CN114466637A - Electric vehicle, control method for electric vehicle, and control program for electric vehicle - Google Patents

Abstract

Provided is an electric vehicle capable of detecting contact with a step with high accuracy and realizing an intended action of a user. The electric vehicle is provided with: a drive unit that drives a wheel including at least one of a front wheel and a rear wheel; a control unit that controls the drive unit to control the step crossing; a measurement unit that measures at least one of a speed and an acceleration applied to a vehicle body on which the wheel is provided; and a determination unit that determines whether or not to perform step crossing control based on a measurement value of the measurement unit.

Description

Electric vehicle, control method for electric vehicle, and control program for electric vehicle

technical field

The present disclosure relates to an electric vehicle for assisting the walking of persons with limited walking, such as the elderly, the disabled, and hospitalized patients, a control method of the electric vehicle, and a control program of the electric vehicle.

Background technique

Conventionally, walking aids, such as walking devices, have been used for assisting elderly people to go out (rollers, push carts), and walking aids such as walking aids for assisting disabled persons or hospitalized patients. For example, Patent Document 1 discloses a walking assist device capable of raising a front wheel on a step without performing an operation that is a heavy burden on the user.

Patent Document 1 discloses a walking assist device (electric vehicle) comprising: a frame; front wheels and rear wheels provided on the frame; a driving force; and a control portion connected to the driving portion for controlling the driving portion to control the driving portion to cause the front wheels to be relative to the rear when it is determined that the front wheels collide with the step even though the user intends to move the electric vehicle forward Wheel suspension.

prior art literature

Patent Literature

Patent Document 1: Japanese Patent Laid-Open No. 2018-61819

SUMMARY OF THE INVENTION

Invention to solve problem

In such a conventional walking assistance device, there is a limitation on the accuracy of detecting the contact with the step, and a sufficiently fine control cannot be performed. Therefore, the step-over-step operation as intended by the user may not be realized. For example, the step detection function and the step overstepping function of the conventional walking assist device are premised on the fact that the walking assist device enters from a substantially front (substantially perpendicular direction) with respect to the step. Therefore, when the right front wheel and the left front wheel of the walking assist device touch the step with a time difference, it is difficult to get over the step. In addition, in order to accurately determine the necessity of the walking assist device to perform the step-over operation, it is necessary to recognize the contact with the step, the stopping operation of the walking assist device by the user, the contact of the walking assist device with an object other than the step, and the like. difference between.

The present disclosure provides an electric vehicle, a control method for the electric vehicle, and a control program for the electric vehicle capable of detecting contact with a step with high accuracy to realize an action intended by a user.

solution to the problem

An electric vehicle according to the present disclosure is characterized by including: a drive unit that drives a wheel including at least one of a front wheel and a rear wheel provided on a vehicle body; and a control unit that causes the drive unit to cause the control over a step in which a wheel goes over a step; a measurement unit that measures at least one of a speed and an acceleration applied to a vehicle body on which the wheel is provided; and a determination unit that determines whether to use the wheel based on the measurement value of the measurement unit The control unit performs step overshoot control.

In the electric vehicle according to the present disclosure, when the determination unit estimates that the front wheel is in contact with a step based on the measurement value of the measurement unit, the step overrunning control may be performed.

In the electric vehicle according to the present disclosure, the step overstepping control may include a control for increasing the driving force of the driving unit for driving the wheels.

In the electric vehicle according to the present disclosure, the step overstep control may include control of turning the vehicle body.

In the electric vehicle according to the present disclosure, the step overrunning control may include control for increasing the driving force while turning the vehicle body.

In the electric vehicle according to the present disclosure, the front wheel may include a left front wheel and a right front wheel that are separately arranged in the width direction of the vehicle body, and the determination unit may be based on a measurement value of the measurement unit to estimate which of the left front wheel and the right front wheel touches the step.

In the electric vehicle according to the present disclosure, the measurement unit may measure at least one of an acceleration in a direction in which the vehicle body is decelerated and an acceleration in a front-rear direction of the vehicle body, and a width of the vehicle body. acceleration in the direction.

In the electric vehicle according to the present disclosure, the rear wheel may include a left rear wheel and a right rear wheel that are separately arranged in the width direction of the vehicle body, and the measurement unit may calculate at least the left rear wheel. The average value of the acceleration in the rotation direction and the acceleration in the rotation direction of the right rear wheel, or the difference between the acceleration in the rotation direction of the left rear wheel and the acceleration in the rotation direction of the right rear wheel.

In the electric vehicle according to the present disclosure, the measuring unit may calculate at least an average value of the acceleration in the rotation direction of the left front wheel and the acceleration in the rotation direction of the right front wheel, or the rotation direction of the left front wheel. The difference between the acceleration of and the acceleration in the direction of rotation of the right front wheel.

In the electric vehicle according to the present disclosure, the measurement unit may measure at least one of an acceleration in a direction in which the vehicle body is decelerated and an acceleration in a rearward direction of the vehicle body, and a width of the vehicle body. The acceleration in the direction, when at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body measured by the measurement unit is equal to or greater than a first threshold value, the determination unit It is estimated which of the left front wheel and the right front wheel is in contact with the step.

In the electric vehicle according to the present disclosure, the measurement unit may measure at least one of an acceleration in a direction in which the vehicle body is decelerated and an acceleration in a rearward direction of the vehicle body, and a width of the vehicle body. The acceleration in the direction within a predetermined period after at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body measured by the measuring unit becomes equal to or greater than a first threshold value When the maximum value of the measured absolute value of the acceleration in the width direction of the vehicle body is equal to or greater than a second threshold value, the determination unit estimates which one of the left front wheel and the right front wheel is in contact with the steps.

In the electric vehicle according to the present disclosure, the measurement unit may measure at least one of an acceleration in a direction in which the vehicle body is decelerated and an acceleration in a rearward direction of the vehicle body. The determination unit estimates that the left front wheel and the right The front wheels all contact the steps, and the third threshold is smaller than the first threshold.

In the electric vehicle according to the present disclosure, the control unit may make only the rear wheel located on the same side as the front wheel estimated to be in contact with the step in the width direction of the vehicle body. The driving portion generates a driving force.

In the electric vehicle according to the present disclosure, the control unit may cause only the front wheel located on the opposite side of the front wheel estimated to be in contact with the step in the width direction of the vehicle body and the front wheel. The drive unit of at least one of the rear wheels generates driving force.

In the electric vehicle according to the present disclosure, the control unit may cause the front wheel and all the front wheels located on the opposite side of the front wheel estimated to be in contact with the step in the width direction of the vehicle body to be in contact with the step. The driving portion of at least one of the rear wheels generates a driving force that is greater than the front wheel estimated to be in contact with the step and the front wheel located in the width direction of the vehicle body. The driving force of the drive unit of at least one of the rear wheels on the same side of the wheel.

In the electric vehicle according to the present disclosure, the control unit may cause the front wheel on a side estimated to be in contact with the step and the rear wheel on the same side in the width direction of the vehicle body. The driving force of the driving portion of at least one of the wheels is greater than the front wheel on the side estimated to be in contact with the step and all the front wheels on the same side as the front wheel in the width direction of the vehicle body. The driving force of the drive unit of at least one of the rear wheels.

In the electric vehicle according to the present disclosure, the control unit may cause the front wheel and all the front wheels located on the opposite side of the front wheel estimated to be in contact with the step in the width direction of the vehicle body to be in contact with the step. The driving force of the drive unit of at least one of the rear wheels, the front wheel estimated to be in contact with the step, and the front wheel located on the same side as the front wheel in the width direction of the vehicle body. The drive force of the drive unit of at least one of the rear wheels is incremented to a fourth threshold value.

In the electric vehicle according to the present disclosure, one of the front wheel and the rear wheel located on the opposite side of the front wheel estimated to be in contact with the step in the width direction of the vehicle body and the rear wheel may be provided. The driving force of at least one of the driving parts is greater than the front wheel estimated to be in contact with the step and the rear wheel located on the same side as the front wheel in the width direction of the vehicle body the driving force of at least one of the driving parts.

In the electric vehicle according to the present disclosure, when the determination unit estimates that both of the front wheels are in contact with a step based on the measurement value of the measurement unit, the control unit may cause the control unit to be in the vehicle body. The driving force of the driving part of at least one of the front wheel and the rear wheel on both sides in the width direction is equal to the driving force of the front wheel or the rear wheel.

In the electric vehicle according to the present disclosure, when the maximum value of the absolute value of the acceleration in the width direction of the vehicle body measured by the measurement unit is equal to or greater than a second threshold value, the control unit may be configured as The fifth threshold value of acceleration, which is a condition for performing the step-over action, is set to be small.

In the electric vehicle according to the present disclosure, as the speed of the vehicle body measured by the measurement unit increases, the control unit may use, as a condition for executing the step-over-moving operation, The sixth threshold value of the absolute value of the acceleration is set to be large.

In the electric vehicle according to the present disclosure, the measurement unit may measure at least one of an acceleration in a direction in which the vehicle body is decelerated and an acceleration in a rearward direction of the vehicle body, and the measurement unit may measure the When at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body is greater than a seventh threshold value, the determination unit estimates that the front wheel touches a step.

In the electric vehicle according to the present disclosure, at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body measured by the measurement unit may be the seventh When the threshold value is less than or equal to the threshold value, the determination unit does not estimate that the front wheel is in contact with the step.

In the electric vehicle according to the present disclosure, the measurement unit may measure a frequency spectrum of vibration of the vehicle body, and when a representative value of the values measured by the measurement unit is greater than an eighth threshold value, the determination unit may estimate for the front wheel to come into contact with the step.

In the electric vehicle according to the present disclosure, when the representative value of the value measured by the measurement unit is equal to or less than the eighth threshold value, the determination unit may not estimate that the front wheel is in contact with a step.

The electric vehicle according to the present disclosure may include a storage unit that stores a measurement value of the measurement unit, and the determination unit may adjust the measurement value based on the measurement value stored in the storage unit. Seventh threshold.

In the electric vehicle according to the present disclosure, after the control unit makes the front wheel go over a step, the determination unit may be within a predetermined period before the control unit performs the step over control of the front wheel When an acceleration smaller than the seventh threshold value is detected, the determination unit changes the seventh threshold value to a smaller value.

In the electric vehicle according to the present disclosure, the acceleration measured by the measurement unit may be greater than the seventh threshold value when the control unit causes the front wheel to go over a step, and the acceleration may be the same as the acceleration. When the difference between the seventh threshold values is larger than a predetermined value, the determination unit changes the seventh threshold value to a larger value.

In the electric vehicle according to the present disclosure, the vibration of the vehicle body may include vibration in the front-rear direction of the vehicle body.

The electric vehicle according to the present disclosure may include a buffer member that covers at least a part of the front of the vehicle body or both side surfaces in the width direction of the vehicle body.

In the electric vehicle according to the present disclosure, the front wheels may be casters configured to be able to turn.

The electric vehicle according to the present disclosure is characterized by comprising: a drive unit that drives a wheel including at least one of a front wheel and a rear wheel; a control unit that controls the drive unit to perform step overstep control; and a measurement a unit that measures at least one of a speed and an acceleration applied to a vehicle body on which the wheel is provided; and a determination unit that determines, based on the measurement value of the measurement unit, whether to cause the control unit to perform step overshoot control, When the determination unit determines that the front wheel is in contact with a step based on the measurement value of the measurement unit, the control unit performs control to increase the driving force of the drive unit for driving the wheel or to cause the Control of the body turning.

A control method for an electric vehicle according to the present disclosure is characterized by comprising the steps of: measuring at least one of a speed and an acceleration applied to a vehicle body; and determining whether to perform a step based on at least one of the speed and the acceleration beyond the control.

The control method for an electric vehicle according to the present disclosure may also further include the steps of: judging whether the front wheel is in contact with a step based on at least one of the speed and the acceleration; and when it is estimated that the front wheel is in contact with the step When a step is used, the step-over control is performed.

In the method for controlling an electric vehicle according to the present disclosure, the step overstepping control may include control for increasing a driving force for driving wheels, control for turning the vehicle body, and turning the vehicle body. At least one of the controls for increasing the driving force.

A control program for an electric vehicle according to the present disclosure is characterized by comprising the steps of: measuring at least one of a speed and an acceleration applied to a vehicle body; and judging whether a front wheel is in contact based on at least one of the speed and the acceleration to a step; and performing a step over control when it is estimated that the front wheel is in contact with the step.

In the control program for an electric vehicle according to the present disclosure, the step overstepping control may include control for increasing a driving force for driving wheels, control for turning the vehicle body, and turning the vehicle body. At least one of the controls for increasing the driving force.

According to the present disclosure, the contact with the step can be detected with high accuracy, and the action intended by the user can be realized.

Description of drawings

FIG. 1 is a perspective view showing an electrically-assisted traveling vehicle according to a first embodiment of the present disclosure.

FIG. 2 is a side view showing the electric-assisted traveling vehicle according to the first embodiment of the present disclosure.

FIG. 3 is a schematic diagram showing a foot detection sensor.

FIG. 4 is a schematic diagram showing a grip sensor.

FIG. 5 is a schematic diagram showing a modification of the grip sensor.

FIG. 6 is a flowchart for explaining an example of the operation of the control unit.

FIG. 7 is a graph showing the change in driving force with the passage of time from the collision of the front wheel to the step.

FIG. 8 is a graph showing an example of an acceleration detected in each case of a collision with a step and a stop operation and a threshold value.

FIG. 9 is a graph showing an example of acceleration detected when colliding with a soft object and acceleration detected when colliding with a step.

FIG. 10 is a schematic diagram showing a configuration example in which a shock absorbing material is provided in front of the vehicle body.

FIG. 11 is a plan view showing an example of acceleration applied to the vehicle body when the electric-assisted traveling vehicle collides with a step.

FIG. 12 is a graph showing a difference in acceleration detected by the collided front wheel.

FIG. 13 is a graph showing an example of the acceleration detected in the case of a turn entry and a straight entry.

FIG. 14 is a graph showing an example of a time waveform of acceleration measured at the time of collision with a step.

FIG. 15 is a plan view showing a first example of the electric-assisted traveling vehicle entered so as to have an angle with respect to the step.

FIG. 16 is a plan view showing a second example of the electric-assisted traveling vehicle entered so as to have an angle with respect to the step.

FIG. 17 is a plan view showing a second example of the electric-assisted traveling vehicle entered so as to have an angle with respect to the step.

FIG. 18 is a graph showing an example of control for turning the electric vehicle after detecting that any one of the front wheels is in contact with the step.

FIG. 19 is a graph showing an example of control for turning the electric vehicle after detecting that any one of the front wheels is in contact with the step.

FIG. 20 is a plan view showing a first example in the case where the front wheels have an angle with respect to the traveling direction of the vehicle body.

FIG. 21 is a plan view showing a second example in the case where the front wheels have an angle with respect to the traveling direction of the vehicle body.

FIG. 22 is a plan view showing an example of a collision of the electric-assisted traveling vehicle with a step.

FIG. 23 is a plan view showing an example of the collision of the electric-assisted traveling vehicle with the step.

FIG. 24 is a perspective view showing an electrically-assisted traveling vehicle according to a second embodiment of the present disclosure.

FIG. 25 is a side view showing an electrically-assisted traveling vehicle according to a second embodiment of the present disclosure.

26 is a side view showing a configuration around a rear wheel of an electrically-assisted traveling vehicle according to a second embodiment of the present disclosure.

27 is a cross-sectional view (a cross-sectional view taken along the line XI-XI in FIG. 25 ) showing a structure around a rear wheel of the electrically-assisted traveling vehicle according to the second embodiment of the present disclosure.

28 is a cross-sectional perspective view showing a structure around a rear wheel of an electrically-assisted traveling vehicle according to a second embodiment of the present disclosure.

FIG. 29 is a schematic diagram showing a modification of the electrically assisted traveling vehicle (during normal traveling).

FIG. 30 is a schematic diagram showing a modification of the electrically assisted traveling vehicle (when the front wheels are locked).

FIGS. 31( a ) and 31 ( b ) are schematic diagrams each showing an electrically-assisted traveling vehicle according to a third embodiment of the present disclosure.

FIGS. 32( a ) and 32 ( b ) are schematic diagrams each showing an electrically-assisted traveling vehicle according to a modification of the third embodiment of the present disclosure.

FIG. 33 is a perspective view showing an electrically-assisted traveling vehicle according to a fourth embodiment of the present disclosure.

Detailed ways

(first embodiment)

First, the first embodiment of the present disclosure will be described with reference to FIGS. 1 to 23 . Hereinafter, the same reference numerals are assigned to the same constituent elements. They have the same name and function. The detailed description is not repeated with respect to the structural elements denoted by the same reference numerals.

FIGS. 1 and 2 are diagrams showing an electric traveling vehicle (hereinafter referred to as an electric-assisted traveling vehicle) as an example of an electric vehicle. FIG. 1 is a schematic perspective view showing an example of the appearance of the electrically-assisted traveling vehicle 10 according to the first embodiment, and FIG. 2 is a side view of the electrically-assisted traveling vehicle 10 of FIG. 1 .

(Structure of Electric Assisted Walking Vehicle)

As shown in FIGS. 1 and 2 , the electric-assisted traveling vehicle 10 includes a frame 11 , a pair of front wheels (wheels) 12 and a pair of rear wheels (wheels) 13 provided on the frame 11 , and a pair of connected to the frame 11 . A handle (operating part) 14 . Two of the pair of rear wheels 13 are arranged so as to be separated from each other in the width direction of the vehicle body. Similarly, two of the pair of front wheels 12 are arranged so as to be separated from each other in the width direction of the vehicle body. Hereinafter, the case where the electric vehicle is mainly a four-wheeled vehicle in which two front wheels and two rear wheels are arranged will be described as an example, but this configuration is merely an example. For example, the electric vehicle may be a tricycle in which one front wheel is provided on the vehicle body, and a pair of (two) rear wheels are arranged so as to be separated from each other in the width direction of the vehicle body. In addition, three or more front wheels may be arranged apart from each other in the width direction. The front wheel arranged on the far right side with respect to the front direction of the vehicle body is called a right front wheel, and the front wheel arranged on the far left side with respect to the front direction of the vehicle body is called a left front wheel. That is, the front wheel includes a left front wheel and a right front wheel which are arranged apart from each other in the width direction of the vehicle body. Furthermore, three or more rear wheels may be arranged to be separated from each other in the width direction. The rear wheel arranged on the far right side with respect to the front direction of the vehicle body is called a right rear wheel, and the rear wheel arranged on the far left side with respect to the vehicle body front direction is called a left rear wheel. That is, the rear wheel includes a left rear wheel and a right rear wheel that are spaced apart in the width direction of the vehicle body. The number of wheels included in the electric vehicle is not particularly limited. Therefore, the electric vehicle may be provided with a different number of wheels than the above.

In addition, each handle 14 is provided with a brake unit 15 for manually stopping the electrically-assisted traveling vehicle 10 . Hereinafter, the frame 11 and the structure supported by the frame 11 as a whole will be referred to as the body of the electrically-assisted traveling vehicle 10 .

The pair of rear wheels 13 are respectively connected to motors 20 for assisting the movement of the corresponding rear wheels 13 . In addition, the electrically-assisted traveling vehicle may include a motor that is coupled to each of the front wheels 12 and assists the movement of each of the front wheels 12 . The front wheels 12 and the rear wheels 13 may be connected to the motor, or only the front wheels 12 may be connected to the motor. The battery 21 and the control unit 16 are respectively mounted in the frame 11 .

Moreover, the control part 16 is provided with the acceleration sensor 22a and the speed sensor 22b. In addition, the handle 14 is provided with an inclination detection sensor 23 and a grip sensor (operation force sensor) 24, respectively. A foot detection sensor 25 for detecting the presence or absence of a user's foot is arranged on the frame 11 at a position below the pair of handles 14 .

Next, each constituent element of the electrically-assisted traveling vehicle 10 will be further described.

The frame 11 includes a pair of left and right duct frames 31 and a connecting frame 32 that connects the pair of duct frames 31 laterally.

A pair of front wheels 12 are respectively provided on the front end sides of each of the pair of left and right duct frames 31 . That is, the two front wheels are arranged apart from each other in the width direction of the vehicle body of the electrically-assisted traveling vehicle 10 . Among the pair of front wheels 12 , the front wheel on the side in the direction R is called a right front wheel, and the front wheel on the side in the direction L is called a right front wheel for distinction. The pair of front wheels 12 are respectively rotatable in the front-rear direction, and are provided so as to be rotatable around the vertical axis.

In addition, a pair of rear wheels 13 are respectively provided on the rear end sides of each of the pair of left and right duct frames 31 . Among the pair of rear wheels 13 , the rear wheel on the side in the direction R in particular is referred to as a right rear wheel, and the rear wheel on the side in the direction L in particular is referred to as a right rear wheel for distinction. Each of the rear wheels 13 is provided so as to be rotatable in the front-rear direction. As a result, the electrically-assisted traveling vehicle 10 can be easily moved forward and backward, and the electrically-assisted traveling vehicle 10 can be easily moved in the left-right direction or changed in direction (turned).

In addition, brake pads 33 that can be mechanically contacted are provided on the outer periphery of each rear wheel 13 .

The brake pad 33 is connected to the brake lever 34 of the brake unit 15 via a lead wire 35 . Therefore, in response to the user manually operating the brake lever 34 , the brake pads 33 operate to brake the rear wheels 13 . In addition, the structure of the mechanical brake is not limited to this, and an arbitrary structure can be used.

In addition, a fall prevention member 36 is provided from the rear end side of each of the pair of left and right duct frames 31 . The fall prevention member 36 is used to prevent the pair of front wheels 12 of the electrically assisted traveling vehicle 10 from being suspended from the ground and falling backward.

A pair of handles 14 are respectively provided on the upper ends of the pair of left and right duct frames 31 . The pair of handles 14 are respectively held by the user's hands. The pair of handles 14 has rod-shaped members 41 . The rod-shaped members 41 are each provided with a grip portion 42 . In addition, the brake levers 34 are attached to the rod-shaped members 41, respectively. In addition, the structure of the handle 14 is not limited to this. For example, a handle extending in the horizontal direction may be provided so as to connect the pair of left and right duct frames 31 , and the handle may be provided with a grip portion 42 as the pair of left and right handles 14 . .

In the present embodiment, as the motor 20, an arbitrary motor such as a servo motor, a stepping motor, an AC motor, and a DC motor can be used. In addition, the motor 20 formed integrally with the reduction gear may also be used. The motor 20 assists the movement of the rear wheel 13 and drives the rear wheel 13 in the forward direction so as to be used during running. In addition, in the present embodiment, the motor 20 also functions as a drive unit that lifts the front wheel 12 with respect to the rear wheel 13 . That is, the driving force of the motor 20 (driving part) generates a moment in a direction in which the front wheel 12 is lifted.

In addition, the motor 20 may function as a generator brake. In this case, the motor 20 further functions as a braking unit for braking the rear wheels 13 . When the motor 20 brakes the rear wheels 13 , the motor 20 is operated as a generator, and the brake is applied by the resistance of the motor 20 . In addition, when the motor 20 functions as a braking unit, the motor 20 may be used as a reverse brake for driving in the opposite direction. The braking portion that brakes the rear wheels 13 may be a different component from the motor 20 . As an example of such a brake part, an electromagnetic brake, a mechanical brake, etc. can be mentioned.

In addition, with regard to the left and right motors 20 , the left and right motors 20 may be independently controlled by the control unit 16 . However, the control unit 16 may control the motor 20 integrally on the left and right when it is not necessary to cause a difference in speed and acceleration between the wheels on the right side of the vehicle body and the wheels on the left side of the vehicle body.

In the present embodiment, the motor 20 is connected to each of the rear wheels 13 (left rear wheel, right rear wheel). However, a structure in which the same motor is connected to both the pair of front wheels 12 and the pair of rear wheels 13 is not excluded.

The control unit 16 controls the drive unit (for example, the above-described motor 20 ) of the electric-assisted traveling vehicle 10 to perform step overrunning control. Here, the step overrunning control refers to a control for causing the front wheel of the vehicle body to ride on the step. The determination unit 16a determines whether or not to perform step overshoot control based on the measurement value of the measurement unit. For example, when it is estimated that the front wheel 12 is in contact with the step, based on the measurement value of the measuring unit, the determination unit 16a determines that the step overstep control is performed. Examples of the measurement unit include acceleration sensors 22a, 81r to 82l, and a velocity sensor 22b, which will be described later. For example, the measurement unit may measure at least one of acceleration in the direction of decelerating the vehicle body, acceleration in the front-rear direction of the vehicle body, and acceleration in the width direction of the vehicle body. This makes it possible to discriminate which one of the left front wheel and the right front wheel is in contact with the step (one-sided contact) or whether both the left and right front wheels are in contact with the step (two-wheel contact).

For example, the control unit 16 and the determination unit 16 a are provided in the vicinity of the battery 21 . The control unit 16 and the determination unit 16a may include a processor capable of executing various commands or programs. The control unit 16 and the determination unit 16a execute, for example, a control program for the electrically-assisted traveling vehicle 10 (electric vehicle). In addition, the control unit 16 and the determination unit 16a may include hardware circuits such as ASIC, FPGA, and PLD, for example. In addition, the electrically-assisted traveling vehicle 10 may include a storage unit 16b. The control unit 16 and the determination unit 16a can read and write data to and from the storage unit 16b. The commands, programs or commands executed by the control unit 16 and the determination unit 16a, data used in the execution of the programs, and measurement values of various sensors (measurement units) are stored in the storage unit 16b. The control unit 16 and the determination unit 16a may be mounted using a common hardware circuit. In addition, the control unit 16 and the determination unit 16a may be installed using a common program. In addition, the control unit 16 and the determination unit 16a may be implemented by different hardware circuits or programs.

The step overstep control by the drive unit may include control to increase the driving force of the drive unit to drive the wheels. In addition, the control for passing the step may include control for turning the vehicle body. The step overrun control may include control to increase the driving force while turning the vehicle body. Details of the processing executed by the control unit 16 and the determination unit 16a will be described later.

The storage unit 16b provides a storage area capable of storing various data. The storage unit 16 b may be provided in the vicinity of the control unit 16 or may be a part of the control unit 16 . The storage unit 16b may be, for example, a volatile memory such as SRAM and DRAM, or a nonvolatile memory such as NAND, MRAM, and FRAM. In addition, a storage device such as a hard disk, an SSD, or an external storage device may be used, and the type of the device is not particularly limited. In addition, the storage unit 16b may be a combination of various types of memory devices and storage devices.

The acceleration sensor 22a measures the acceleration in the front-rear direction of the vehicle body and the acceleration in the width direction of the vehicle body. Therefore, the acceleration in the front-rear direction of the vehicle body refers to the acceleration in the direction FB in FIG. 1 . In addition, the acceleration in the width direction of the vehicle body refers to the acceleration in the direction L and the direction R in FIG. 1 . As will be described later, the acceleration sensor 22a may measure the acceleration in the direction of decelerating the vehicle body in addition to the acceleration in the front-rear direction of the vehicle body. In addition, the acceleration sensor 22a may measure the acceleration in the direction in which the vehicle body is decelerated instead of measuring the acceleration in the front-rear direction of the vehicle body. The control unit 16 can acquire the acceleration measured by the acceleration sensor 22a. As an example of a sensor that measures the acceleration applied to the vehicle body, a MEMS sensor or the like can be cited, but any type of device may be used.

In addition, a piezoelectric sensor, a strain gauge, an operation force sensor (for example, a grip sensor), etc. may be used to measure the force applied to the electrically-assisted traveling vehicle 10 or any one of the components of the electrically-assisted traveling vehicle 10 to obtain Estimated value of acceleration.

In addition, the acceleration sensor may measure the acceleration in the rotational direction of each wheel of the electric-assisted traveling vehicle 10 . For example, the acceleration sensors 81r to 82l of FIG. 1 measure the acceleration in the rotational direction of each wheel. Specifically, the acceleration sensor 81r measures the acceleration of the right front wheel (the front wheel 12 on the direction R side). The acceleration sensor 811 measures the acceleration of the right front wheel (the front wheel 12 on the direction L side). The acceleration sensor 82r measures the acceleration of the right rear wheel (the rear wheel 13 on the direction R side). The acceleration sensor 821 measures the acceleration of the right rear wheel (the rear wheel 13 on the direction L side).

The acceleration sensors 81r to 82l may directly measure the acceleration of each wheel, or may measure the acceleration of the motor 20 to provide an estimated value of the acceleration of the wheel. Alternatively, the speed of the wheel or motor 20 may be measured to calculate an estimate of acceleration. In addition, the estimated value of the acceleration may be obtained by measuring the rotational speed per unit time of the wheel or the motor 20 to calculate the time differential of the rotational speed. The control unit 16 can acquire the accelerations measured by the acceleration sensors 81r to 82l.

The speed sensor 22b detects the rotational speed or speed of the rear wheel 13 and transmits a signal of the rotational speed or speed to the control unit 16 . The speed sensor 22b can be provided in the vicinity of the control unit 16, for example. In addition, the speed sensor 22b may be built in the inside of the pair of rear wheels 13 of the electrically-assisted traveling vehicle 10 . Alternatively, the speed sensor 22b may be built in only the inside of the pair of front wheels 12 , or may be built in all of the pair of front wheels 12 and the pair of rear wheels 13 . As an example of the velocity sensor, a gyro sensor that measures angular velocity can be cited. By using a gyro sensor, it is possible to detect which of the left and right wheels collided with an object such as a step.

When the motor 20 is a brushless motor, the speed sensor 22b may use the Hall element built in the motor 20 to calculate the rotational speed or speed of the wheels and the speed of the electric-assisted traveling vehicle 10 .

In addition, when the speed detection can be performed based on the counter electromotive force of the motor 20, the rotation speed or speed of the wheels and the speed of the electrically assisted traveling vehicle 10 are calculated based on the counter electromotive force, and each rear wheel 13 or each front wheel 10 is configured to be able to detect the speed. In the case of detecting the angular velocity of the wheel 12 , the rotational speed or speed of the wheel and the speed of the electrically-assisted traveling vehicle 10 can be calculated from the angular velocity.

In addition, the speed sensor 22b is not limited to being incorporated in the pair of front wheels 12 and the pair of rear wheels 13, and may be attached to other arbitrary members such as the frame 11 and the pair of handles 14. Alternatively, the velocity may be calculated by integrating the acceleration measured by the acceleration sensor. In addition, in the case of using GPS (Global Positioning System), the velocity can also be calculated based on the displacement per unit time of the coordinates.

The acceleration in the direction of decelerating the vehicle body (negative acceleration) may be measured using the speed sensor 22b and the acceleration sensors 81r to 82l. First, the traveling direction of the vehicle body is determined based on the measurement value of the speed sensor 22b. Then, the directions of the accelerations measured by the acceleration sensors 81r to 82l are determined. When the direction of the measured acceleration includes a component in the opposite direction to the traveling direction of the vehicle body, the acceleration of the component can be the acceleration in the direction of decelerating the vehicle body.

The tilt detection sensor 23 detects the tilt of the electrically-assisted traveling vehicle 10, for example, whether the electrically-assisted traveling vehicle 10 is on a flat surface or an inclined surface, and transmits a signal related to the tilt of the electrically-assisted traveling vehicle 10 to the determination unit 16a. The determination unit 16a may estimate whether the electric-assisted traveling vehicle 10 has successfully climbed over the steps based on the measurement value of the inclination sensor 23 . The inclination detection sensor 23 is provided in the upper part of the electric-assisted traveling vehicle 10 , for example, inside the pair of handles 14 . The inclination detection sensor 23 can also be provided in the lower part of the electric-assisted traveling vehicle 10 , but by arranging it in the upper part, the posture of the electric-assisted traveling vehicle 10 can be detected more reliably than when the inclination detection sensor 23 is arranged in the lower part. In addition, as the tilt detection sensor 23, a gyro sensor can also be used. In addition, an acceleration sensor may be used to detect the inclination of the electrically-assisted traveling vehicle 10 .

FIG. 3 is a schematic diagram showing an example of the foot detection sensor 25 . As shown in FIG. 3 , the foot detection sensor 25 is provided on the connection frame 32 . As an example of the foot detection sensor 25, an image sensor, an infrared sensor, etc. can be mentioned. The foot detection sensor 25 can detect the movement of the foot by measuring the distance from the lower part of the foot of the user of the electrically assisted walking vehicle 10 .

Specifically, the foot detection sensor 25 of FIG. 3 can determine whether the user's feet want to move within the range AR, or want to stop, separate, approach, or sit on the seat surface 37 toward the rear.

4 and 5 are schematic diagrams for explaining the grip sensor 24 .

Grip sensors 24 for detecting an operating force (grip force) of the electric-assisted traveling vehicle 10 by the user's hand are respectively provided on the grip portions 42 of the pair of handles 14 . The grip sensor 24 restricts movement in either or both of the pushing direction and the pulling direction with respect to the rod-shaped member 41 by an elastic member (eg, a spring) not shown, and includes a potentiometer for detecting the movement.

As described above, the grip portion 42 can move in the front-rear direction with respect to the rod-shaped member 41 , and when it moves in the direction of the arrow (front direction) in FIGS. 4 and 5 , it can be determined that the electric-assisted walking is being pushed by the user When the vehicle 10 moves in the opposite direction (rear direction) of the arrows in FIGS. 4 and 5 , it can be determined that the electric-assisted traveling vehicle 10 is being pulled by the user, and when the vehicle 10 does not move in either direction, it can be determined that It is determined that neither of these movements is performed.

As a result, it can be recognized that the user intends to move the electrically-assisted traveling vehicle 10 forward, the user intends to move the electrically-assisted traveling vehicle 10 backward, or the user does not intend to change the state of the electrically-assisted traveling vehicle 10 .

An independent grip sensor 24 is provided on the pair of left and right handles 14, respectively. Each grip sensor 24 independently detects the operation force (grip force) on the handle 14, and transmits the detected operation force to at least one of the control unit 16 and the determination unit 16a. Therefore, at least one of the control unit 16 and the determination unit 16a can recognize that the user is holding only one of the pair of handles 14 (one-handed holding state), not holding both of the pair of handles 14 (two-handed state), or Both of the pair of handles 14 are held (the state of being held by both hands).

In addition, as shown in FIG. 5 , a strain sensor 38 (eg, a strain gauge) may be provided on the grip portion 42 so as to detect the moment applied to the grip portion 42 or the pair of pipe frames 31 , and the strain sensor 38 may be used as a The sensor 24 is held. In this case, since the grip portion 42 is fixed with respect to the rod-shaped member 41, the structure can be simplified. In addition, a joystick, a push button, or a proximity sensor that detects the user's hand may be provided in the grip portion 42 , and this proximity sensor may be used as the grip sensor 24 . That is, in the case of "it is determined that the user intends to move the electric vehicle forward via the operation unit (the user performs the forward operation of the electric vehicle)", except that the operation unit is pushed or pulled by the user's hand or a part of the body, In addition to the case of detecting the user's operation force given to the operation part, the case of detecting the user's operation by a switch means such as a joystick and a push button is also included.

(Outline of Electric Assisted Walking Vehicle)

The electrically-assisted traveling vehicle 10 (electric vehicle) includes a drive unit that drives a wheel including at least one of a front wheel and a rear wheel provided on a vehicle body, and a control unit 16 that causes the drive unit to cause the Control over the step of the wheel over the step; a measurement unit that measures at least one of a speed and an acceleration applied to the vehicle body provided with the wheel; and a determination unit 16a that determines whether or not to perform the step over based on the measurement value of the measurement unit control. When the determination unit 16a determines that the front wheel is in contact with the step based on the measurement value of the measurement unit, the control unit of the electrically assisted traveling vehicle 10 may perform control to increase the driving force of the driving unit for driving the wheels, or to turn the vehicle body. control. Thereby, the electrically-assisted traveling vehicle 10 can detect the collision (contact) with the step, and can also determine the form of contact with the step. In addition, the electrically-assisted traveling vehicle 10 can perform a step-over-step operation of an appropriate content at an appropriate timing.

In the following, description will be given by taking, as an example, a case where the control unit 16 transmits a command based on an algorithm of step overrun control to the drive unit to operate the drive unit. However, the allocation of processing in each component may be different from this. For example, the control unit 16 may send a command to start the step overstep control to the drive unit, and the drive unit may start the operation based on the step overstep control algorithm set in itself.

The determination unit 16a discriminates, based on the measurement value (including at least one of speed and acceleration) of the measurement unit, the contact of the electric assisted traveling vehicle with the step, the stop operation by the user, and the collision with an object other than the step. In addition, the determination unit 16a can estimate the traveling direction of the electrically-assisted traveling vehicle with respect to the step (the angle of the electrically-assisted traveling vehicle with respect to the step) based on the measurement value.

When the contact with the step is detected, the control unit 16 performs a step over the step according to the estimated traveling direction (angle) of the electric-assisted traveling vehicle with respect to the step. Examples of the step-over-ride movement include turning of the vehicle body, assistance by the drive unit connected to the front wheels, and combination of the vehicle body turning and assistance by the drive unit connected to the front wheels.

In addition, the control method for an electrically assisted walking vehicle (electric vehicle) may also include the steps of: measuring at least one of the speed and acceleration applied to the vehicle body; determining whether there is a step or not based on at least one of the speed and the acceleration; When there is a step, the step-over action is performed.

The control of the electrically-assisted traveling vehicle (electric vehicle) can also be realized by hardware such as a program, a processor, and an electronic circuit mounted on the electrically-assisted traveling vehicle, or a combination thereof. In addition, the electrically-assisted traveling vehicle may receive a wireless signal from the outside and be controlled based on a control signal transmitted from an external control device (information processing device).

(Function of this embodiment)

Next, the operation of the present embodiment having the above-described configuration will be described. FIG. 6 is a flowchart for explaining an example of the operation of the control unit 16 .

First, the control unit 16 determines whether or not the front wheel 12 has collided with a step while the user is operating the electric-assisted traveling vehicle 10 to move forward. In this case, first, the control unit 16 determines whether or not the pair of handles 14 on the left and right has been pressed for a fixed time or longer (for example, 1 second, for example) based on the signals detected from the grip sensors 24 respectively provided in the pair of handles 14 on the left and right. above) (step S101).

In addition, the control unit 16 may use the value (absolute value) of the change in the operation force in addition to the value (absolute value) of the operation force, thereby determining whether the handle 14 is fixed by the user's hand or not. Press hard. In this case, it can be determined more accurately whether the handle 14 is pressed by the user's hand with a force equal to or higher than a fixed value. For example, when the absolute value of the operating force is equal to or less than a predetermined value and the absolute value of the change in the operating force (differential value of the operating force) is equal to or less than a predetermined value, it may be determined that the handle 14 is not covered by the user's hand. In other cases, it is determined that the handle 14 is pressed by the user's hand with a force greater than or equal to a fixed force. In addition, it may be determined that the handle 14 is not grasped by the user's hand when the operating force and the change in the operating force are within an elliptical region bounded by a rectangular numerical range divided by each predetermined value. In this case, determination can be made with higher accuracy.

Here, when the pair of handles 14 is not pressed with a force more than fixed (step S101 : NO), it is determined that the user does not intend to move the electric-assisted traveling vehicle 10 forward, and the following control is not performed. In this case, the control unit 16 may brake the rear wheels 13 by using the motor 20 as a generator brake.

On the other hand, when the pair of handles 14 is pressed for a fixed time or longer by a fixed force or more (step S101 : YES), the control unit 16 determines that the user intends to move the electric-assisted traveling vehicle 10 forward. Next, the control part 16 determines whether the front wheel 12 collides with a step (step S102).

Specifically, the speed sensor 22b detects the rotational speed or speed of the rear wheel 13 and transmits a signal of the rotational speed or speed to the control unit 16 . The control unit 16 calculates the speed of the rear wheels 13 based on the transmitted signal, and compares the speed with a predetermined speed (threshold value) V determined in advance.

Assuming that when the rear wheels 13 are being driven, that is, when the rear wheels 13 are moving at a speed higher than the predetermined speed V (step S102: YES), the control unit 16 determines that the electrically-assisted traveling vehicle 10 is running at a normal speed. In the state of walking, the motor 20 is used to continuously assist the movement of the rear wheel 13 .

On the other hand, when the rotation of the rear wheels 13 is stopped and the speed is 0 (the movement of the electrically-assisted traveling vehicle 10 is stopped), or when the vehicle moves at a predetermined speed V or less determined in advance (the traveling speed of the electrically-assisted traveling vehicle 10 is constant) In the case of the following) (step S102: NO), the control unit 16 estimates, based on the measurement value (including at least one of the speed and the acceleration) of the measurement unit, whether the electric-assisted traveling vehicle has collided with the step, or whether an accident has occurred due to Any of other events such as a stop operation by the user and a collision with an object other than a step.

In addition, when the control unit 16 determines that the electric-assisted traveling vehicle has collided with the step (step S103 : YES), the control unit 16 estimates based on the measurement value (including at least one of speed and acceleration) of the measurement unit The traveling direction (angle) of the electric vehicle with respect to the step is assisted (step S104). Then, a step over the step is performed according to the estimated traveling direction (angle) of the electric-assisted traveling vehicle with respect to the step (step S105 ). Examples of the step-over-ride movement include turning of the vehicle body, assistance by the drive unit connected to the front wheels, and combination of the vehicle body turning and assistance by the drive unit connected to the front wheels. The step-over action may also include the action of raising the front wheel.

In addition, the details of the processing of the control unit 16 for detecting a collision with the step (step S103 ), the processing for estimating the traveling direction of the electric-assisted traveling vehicle with respect to the step (step S104 ), and the operation of crossing various steps (step S105 ) are given in It will be described later. As will be described later, in steps S103 to S105 , the difference in control processing for the left and right components, and the direction of the detected speed and acceleration are important. The difference in the control processing related to the left and right components will be described later, and an example of the operation of raising the front wheel will be described below first.

When the operation to lift the front wheels is performed, the control unit 16 controls the motor 20 (driving unit) to increase or decrease the driving force of the motor 20 in accordance with, for example, the force of pressing the handle 14 (operation force applied to the handle 14 ). . Since the front wheel 12 collides with the step and the electric-assisted traveling vehicle 10 cannot move forward, the driving force in the forward direction of the rear wheel 13 causes the electric-assisted traveling vehicle 10 to generate a moment in the direction of raising the front wheel 12 . Therefore, the front wheel 12 can be lifted with respect to the rear wheel 13 .

When the control unit 16 determines that the user intends to move the electric-assisted traveling vehicle 10 forward (intention to move forward), the control unit 16 can accurately determine that the user intends to move forward by using the time and force when the handle 14 is pressed as described above, thereby avoiding Judgment that is different from the user's intention. Thereby, the user can use the electrically-assisted traveling vehicle 10 with greater peace of mind. In this determination, only the force with which the handle 14 is pressed can be used. For example, when the handle 14 is pressed with a force equal to or greater than a fixed value, it is determined that the user intends to move the electric-assisted traveling vehicle 10 forward. In this case, the control unit 16 can quickly determine that the user intends to move forward, and the user can raise the front wheels 12 without significantly reducing the walking speed.

In addition, the control unit 16 may use the acceleration of the rear wheel 13 in addition to the speed of the rear wheel 13 when determining whether the front wheel 12 collides with the step. Thereby, it can be determined with higher accuracy whether or not the electric-assisted traveling vehicle 10 is moving. For example, when the speed of the rear wheels 13 is equal to or less than a predetermined speed V, and the acceleration of the rear wheels 13 is equal to or less than a predetermined acceleration, it may be determined that the electric-assisted traveling vehicle 10 has collided with a step. In this case, it is determined that the electrically-assisted traveling vehicle 10 does not collide with the step.

Alternatively, the speed of the rear wheels 13 may be equal to or less than a predetermined speed V close to 0, and the deceleration (negative acceleration) of the electrically-assisted traveling vehicle 10, that is, the deceleration (negative acceleration) of the rear wheels 13 may be predetermined. When the threshold value (threshold value) is greater than or equal to the threshold value, the control unit 16 determines that the front wheel 12 collides with the step regardless of the user's intention to move the electric-assisted traveling vehicle 10 forward (intentional forward operation operation). That is, when the speed of the rear wheel 13 is a value close to 0 and the deceleration of the rear wheel 13 is a fixed value or more, it is considered that the front wheel 12 collided with the step and stopped suddenly. In this case, it can be determined that the front wheel 12 has collided with the step without using the information from the grip sensor 24 . Therefore, it is not necessary for the electrically-assisted traveling vehicle 10 to include the grip sensor 24 . In addition, the deceleration is negative acceleration as described above, and the value of the deceleration is positive when the electrically-assisted traveling vehicle 10 is decelerating, and the value of the deceleration is negative when the electrically-assisted traveling vehicle 10 is accelerating.

In addition, when the pair of handles 14 is pressed for a fixed time or longer by a force equal to or greater than a fixed value, and the deceleration (negative acceleration) of the rear wheel 13 is equal to or greater than a predetermined threshold value, the user may make the electric assist The traveling vehicle 10 moves forward (intention to move forward), but the control unit 16 determines that the front wheel 12 has collided with the step. Thereby, it can be determined with higher accuracy whether or not the electrically-assisted traveling vehicle 10 is moving. Further, as described above, it can be determined based on the detection signal from the grip sensor 24 whether or not the pair of handles 14 has been pressed for a fixed time or longer by a force equal to or greater than a fixed value. Further, the collision of the step 12 with the step may be determined using the acceleration in the rearward direction of the vehicle body instead of the negative acceleration.

When the step is relatively low, the front wheel 12 can be lifted by the driving force of the rear wheel 13 described above, and the front wheel 12 can climb the step. Here, in the case where the front wheel 12 is not raised, the user then weakens the force for pressing the handle 14 . At this time, the moment in the direction in which the front wheel 12 is pushed down (the moment against the lift of the front wheel 12 ) in the electrically-assisted traveling vehicle 10 is reduced. The control unit 16 maintains the driving force in the forward direction of the rear wheels 13 to be more than constant and drives the rear wheels 13 forward (see FIG. 7 ). Thereby, the moment in the direction of lifting the front wheel 12 increases, and acts to lift the front wheel 12 .

Even when the front wheel 12 is not raised, the user then performs an operation of pulling the handle 14 rearward. At this time, the force pulling the handle 14 rearward generates a moment in the direction in which the rear wheel 13 is used as an axis to lift the front wheel 12 , and acts together with the driving force of the rear wheel 13 to lift the front wheel 12 . In this way, in addition to the operating force from the motor 20, the electric-assisted traveling vehicle 10 generates a moment in the direction of lifting the front wheel 12 by operating the operating handle 14 by the user (refer to the arrow M in FIG. 2), thereby enabling more The front wheel 12 is securely lifted (the electric-assisted walking vehicle 10 is supported by the rear wheel). Alternatively, the front wheel 12 may be lifted by the user stepping on a pedal (not shown) fixed to the rear of the rotation shaft of the rear wheel 13 instead of pulling the handle 14 rearward by the user.

At this time, as the front wheel 12 is lifted relative to the rear wheel 13, a gap is generated between the front wheel 12 and the step. Since the rear wheel 13 is driven in the forward direction, the electric-assisted traveling vehicle 10 moves forward to fill the gap, and the front wheel 12 can be brought into contact with the upper stage of the step. As a result, the front wheel 12 can smoothly climb the steps.

After raising the front wheels 12, the control unit 16 gradually reduces the driving force in the forward direction of the rear wheels 13 by the first decrease amount. In this case, the rear wheel 13 is not accelerated excessively after the front wheel 12 passes over the step, and therefore, the front wheel 12 can smoothly pass over the step. The timing at which the reduction of the driving force is started can be set so as not to satisfy a predetermined condition when the control unit 16 controls the driving unit to raise the front wheel 12 (when the user intends to electrically assist the forward operation of the traveling vehicle 10, it is determined that the front wheel 12 is connected to the front wheel 12 ). conditions for step collision). For example, when the handle 14 is not pressed with a force greater than or equal to the fixed force (when the user reduces the force for pressing the handle 14 or when the handle 14 is pulled backward), or when the rear wheel 13 rotates at a fixed speed or more in the forward direction Time.

After that, the user presses the pair of handles 14 in a state where the front wheel 12 is raised relative to the rear wheel 13 . Thereby, the electrically-assisted traveling vehicle 10 is moved forward, and the front wheel 12 can go over the step.

In this way, when the user pulls the handle 14 rearward, a moment around the rear wheel 13 can be generated, so that the front wheel 12 can be easily lifted in accordance with the driving force of the motor 20 . Therefore, the front wheel 12 can easily go over the steps without raising the electric assist traveling vehicle 10 by the user. In addition, as described above, in the case where the steps are low, etc., the front may be lifted only by the increase of the driving force of the motor 20 (driving part) without accompanying the operation of pulling the handle 14 rearward by the user. round 12.

In a state where the output of the motor 20 is increased after the front wheel 12 has passed the step, the electrically-assisted traveling vehicle 10 may be over-accelerated. Therefore, the control unit 16 may determine that the front wheel 12 has passed over when any of the following conditions (1) to (3) is satisfied after the front wheel 12 is raised relative to the rear wheel 13 . Steps, the electrically assisted traveling vehicle 10 does not further accelerate. In this case, the control unit 16 controls the motor 20 to further increase the reduction amount of the driving force of the rear wheel 13 of the motor 20 . Specifically, the reduction amount of the driving force in the forward direction of the rear wheels 13 is set to a second reduction amount larger than the above-described first reduction amount (refer to the two-dot chain line in FIG. 7 ). Alternatively, the control unit 16 may make the driving force in the forward direction of the rear wheels 13 to be zero.

(1) When the inclination angle of the electrically-assisted traveling vehicle 10 detected by the inclination detection sensor 23 is equal to or greater than a fixed value (because the electrically-assisted traveling vehicle 10 is inclined when the front wheels 12 climb the steps).

(2) When the rotational speed of the rear wheel 13 detected by the speed sensor 22b satisfies a predetermined condition. For example, when the rotational speed of the rear wheels 13 is equal to or higher than a fixed value (because the speed of the rear wheels 13 increases at the moment when the front wheels 12 go over the step. In addition, it is because the rotational speed of the rear wheels 13 is caused when the rear wheels 13 are idling. rise).

(3) In the case where the distance between the user and the electric-assisted walking vehicle 10 detected by the foot detection sensor 25 is a fixed value or more The electrically assisted walking vehicle 10 is kept away from the user).

In addition, when it is determined that the user intends to move the electric vehicle forward (intention to move forward), the method is not limited to the above-mentioned method. Outputs from the strain gauges of the electrically-assisted traveling vehicle 10, (iii) the air pressure of the tires of the front wheels 12 or the rear wheels 13, (iv) the acceleration in the front-rear direction of the electrically-assisted traveling vehicle 10, (v) from the handle 14 provided One or more elements selected from the output of the pressure sensor such as (vi) the output from the myoelectric sensor provided in the handle 14 or the like, and (vii) the movement of the user's foot.

(step detection)

Next, the details of the process of detecting the collision of the electrically assisted traveling vehicle (electric vehicle) with the step will be described.

As an example of the detection of a step by a conventional electric-assisted traveling vehicle (electric vehicle), the detection of a step by acceleration can be mentioned. However, the acceleration detection of the electrically-assisted traveling vehicle is not limited to the time of collision with a step. For example, the acceleration is detected even when the user performs a stop operation of the electric-assisted traveling vehicle, and the acceleration is also detected when the electric-assisted traveling vehicle collides with an object other than a step. In order to improve the detection accuracy of the step, it is necessary to discriminate the difference between the acceleration detected when the electrically assisted traveling vehicle collides with the step and the acceleration detected when the user performs a stop operation of the electrically assisted traveling vehicle. Likewise, differences in detected accelerations due to the type of object that the electrically assisted walking vehicle collided with must also be considered.

FIG. 8 is a graph showing an example of an acceleration and a threshold value detected in each case of a collision with a step and a stop operation. The horizontal axis of the graph of FIG. 8 represents the speed of the vehicle body of the electrically-assisted traveling vehicle 10 (electric vehicle). In addition, the vertical axis of the graph of FIG. 8 represents a negative acceleration. The negative acceleration refers to the acceleration (deceleration) in the direction of decelerating the electrically-assisted traveling vehicle 10 (electric vehicle).

In FIG. 8 , the relationship between the speed measured at the time of the collision with the step and the stop operation by the user and the negative acceleration is plotted. Referring to FIG. 8 , upon collision with a step, an acceleration greater than that at the time of the stop operation by the user is detected due to the impact applied to the electric-assisted traveling vehicle 10 . That is, the measurement unit only needs to measure at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body. In this case, when at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body measured by the measurement unit is greater than a threshold (seventh threshold), the determination unit 16a may estimate For the front wheel 12 to touch the step. In addition, when at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body measured by the measurement unit is equal to or less than a threshold value, the determination unit 16a may not estimate that the front wheel 12 is in contact with steps. Thereby, the contact between the front wheel 12 and the step can be determined.

For example, when an acceleration smaller than a threshold is detected in a fixed period before the step overshooting control (that is, when it is determined that the front wheel 12 is in contact with the step), the threshold is set too large, although the front wheel 12 It may not be judged that the step is actually touched. Therefore, after the control unit 16 makes the front wheel 12 go over the step, the determination unit 16a may detect an acceleration smaller than the threshold value (seventh threshold value) within a predetermined period before the control unit 16 executes the step overshoot control of the front wheel 12 . In this case, the threshold value (seventh threshold value) is changed to a smaller value. In addition, when the acceleration detected before the step overstep control is performed (ie, when it is determined that the front wheel 12 is in contact with the step) is larger than the threshold value and the difference between the detected acceleration and the threshold value is larger than a predetermined value, the set value of the threshold value Possibly too small. Therefore, when the control unit 16 makes the front wheel 12 go over the step, the acceleration measured by the measurement unit may be larger than the threshold value (seventh threshold value) and the difference between the acceleration and the threshold value (seventh threshold value) may be larger than a predetermined value. The determination unit 16a changes the threshold value (seventh threshold value) to a larger value. In this way, when the front wheel 12 successfully goes over the step, the threshold value used for the determination of the contact between the front wheel 12 and the step is adjusted, whereby the accuracy of step contact detection can be improved.

As described above, the electrically-assisted traveling vehicle 10 may include the storage unit 16b that stores the measurement values of the measurement unit. In this case, the determination unit 16a may adjust the threshold value (seventh threshold value) based on the measurement value stored in the storage unit 16b. The threshold value can be adjusted with higher accuracy by using the measured values at the time of step overshoot control stored in the storage unit 16b in the past multiple times. In addition, it is not limited to the seventh threshold value, and other threshold values described in this specification may be adjusted based on the measurement value stored in the storage unit 16b.

Referring to FIG. 8 , it can be seen that the speed of the electrically-assisted traveling vehicle 10 increases with the stop operation performed by the user when it collides with a step, and a large acceleration tends to be detected. In addition, when the speed measured in each case and the acceleration in the rearward direction of the vehicle body are plotted in the graph, the same relationship as in FIG. 8 holds.

The same threshold value is not always used to detect the collision with the step, and the threshold value used can be increased according to the speed of the electrically-assisted traveling vehicle 10 . Then, when the measured acceleration is larger than the threshold value, the electric-assisted traveling vehicle 10 can perform the step-over-stepping motion. As the speed of the vehicle body of the electrically-assisted traveling vehicle 10 (electric vehicle) measured by the measuring unit increases, the control unit 16 may set the threshold value of the absolute value of the acceleration as a condition for performing the step-over-moving operation (No. Six thresholds) are set large. An example of such a threshold (fourth threshold) is shown by the broken line in FIG. 8 . Thereby, the detection accuracy of the step can be improved.

In addition, as an example of the function of the threshold value, T=Σ(α _n v＾β _n )+γ can be cited, but forms different from these may be used. Here, v is the speed of the vehicle body, and α _n and β _n are coefficients (positive real numbers) larger than 0. γ is an arbitrary coefficient. γ can be either a positive real number, 0 or a negative real number. In addition, when the structure and the material to be used differ depending on the side surface of the electric-assisted traveling vehicle 10, a threshold value or a function of the threshold value that differs depending on the direction may be used. For example, when at least any one of the material, structure, and size of the front wheel and the rear wheel is different, different coefficients may be used for the detection of the collision between the front wheel and the step and the collision between the rear wheel and the step.

FIG. 9 is a graph showing an example of acceleration detected when the electric-assisted walking vehicle 10 collides with a soft object and acceleration detected when it collides with a step. Here, the soft object refers to an object having a smaller rebound hardness than that of a step. As an example of such an object, a human body can be cited. The horizontal axis of the graph of FIG. 9 represents the speed of the vehicle body of the electrically-assisted traveling vehicle 10 (electric vehicle). In addition, the vertical axis of the graph of FIG. 9 represents negative acceleration (deceleration).

In FIG. 9 , the relationship between the measured speed and the negative acceleration is plotted when the electrically-assisted traveling vehicle 10 collides with a soft object and when the electrically-assisted traveling vehicle 10 collides with a step. Referring to FIG. 9 , it can be seen that when the speed of the electrically-assisted traveling vehicle 10 is at the same level, when the electrically-assisted traveling vehicle 10 collides with a step, the detection is greater than when the electrically-assisted traveling vehicle 10 collides with a soft object acceleration. From the results, it can be seen that the magnitude of the rebound hardness of the object with which the electrically-assisted walking vehicle 10 collides can be estimated from the magnitude of the acceleration detected at the time of the collision. For example, by comparing the detected acceleration with a threshold value, a collision with a step and a collision with a human body can be distinguished. In the graph of FIG. 9 , the negative acceleration (acceleration in the direction of decelerating the vehicle body) is shown, but the same relationship holds even if the graph is created using the acceleration in the rearward direction of the vehicle body instead of the negative acceleration.

In addition, also in the example of FIG. 9, there exists a tendency for the detected acceleration to become larger as the speed of the electrically-assisted traveling vehicle 10 becomes larger.

The determination unit 16a of the electrically-assisted traveling vehicle 10 can determine whether or not the step-over-stepping operation is performed by comparing the measured acceleration with a threshold value. For example, when at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body measured by the measurement unit is equal to or less than a predetermined threshold value, the determination unit 16a may estimate that the front wheels 12 are in contact with each other. to objects other than steps. At least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body of the electrically-assisted traveling vehicle 10 (electric vehicle) measured by the measurement unit may be equal to or less than a threshold value (fourth threshold value) At this time, the determination unit 16a does not cause the driving unit to perform the step-over-stepping operation. This makes it difficult to perform a step-over-step operation when the electrically-assisted traveling vehicle 10 is stopped by the user or when the electrically-assisted traveling vehicle 10 may come into contact with a person, and the safety of the electrically-assisted traveling vehicle 10 can be improved.

When the acceleration in the direction of decelerating the vehicle body or the acceleration in the rearward direction of the vehicle body of the electrically assisted traveling vehicle 10 (electric vehicle) measured by the measurement unit is larger than a threshold value (fourth threshold value), the determination unit 16a may The drive unit performs a step-over operation. Generally speaking, when the acceleration in the direction of decelerating the electric vehicle (deceleration) or the acceleration in the rearward direction of the vehicle body is larger than a threshold value, it can be estimated that the electric vehicle has touched a step. For example, the measurement unit may measure at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body, and the acceleration in the direction of decelerating the vehicle body measured by the measurement unit and the acceleration in the direction of the vehicle body may be measured. When at least one of the accelerations in the rearward direction is larger than a predetermined threshold value (fifth threshold value), the determination unit 16a estimates that the front wheel 12 has touched the step. Thereby, only when the determination part 16a determines that it collided with a step, the drive part can be made to perform the operation|movement of overstepping a step.

In addition, the control method for an electrically assisted traveling vehicle (electric vehicle) may include the steps of: measuring at least one of speed and acceleration applied to the vehicle body; and judging whether or not to cross the step based on at least one of the speed and the acceleration control. In addition, the control method for an electrically assisted traveling vehicle (electric vehicle) may further include the steps of: judging whether the front wheel 12 has touched the step based on at least one of speed and acceleration; and when it is estimated that the front wheel 12 has touched the step When the step is over the control. Further, the step overstepping control may include at least any one of control for increasing the driving force for driving the wheels, control for turning the vehicle body, and control for increasing the driving force while turning the vehicle body.

In addition, the control program of the electrically assisted walking vehicle (electric vehicle) may also include the steps of: measuring at least one of the speed and acceleration applied to the vehicle body; step; and when it is estimated that the front wheel 12 is in contact with the step, the step-over control is performed. Further, the step overstepping control may include at least any one of control for increasing the driving force for driving the wheels, control for turning the vehicle body, and control for increasing the driving force while turning the vehicle body. The control program may be executed by the control unit 16 or the determination unit 16a, or may be executed by an external controller, server, or the like.

In addition, in order to obtain the acceleration in the direction of decelerating the electrically-assisted traveling vehicle 10 (electric vehicle), that is, the negative acceleration (deceleration), the traveling direction of the electrically-assisted traveling vehicle 10 needs to be determined. The traveling direction of the electrically-assisted traveling vehicle 10 can be estimated based on, for example, the measurement value of the speed sensor 22b.

In addition, the acceleration used for determining whether or not the electrically-assisted traveling vehicle 10 is going over a step is not limited to a negative acceleration (deceleration). For example, the determination unit 16a may determine whether to cause the control unit 16 to execute the step overpass control based on the acceleration applied in the rearward direction of the vehicle body of the electrically assisted traveling vehicle 10 (electric vehicle) measured by the measurement unit. When the determination is made based on the acceleration of the electrically assisted traveling vehicle 10 in the rearward direction of the vehicle body, the traveling direction of the vehicle body may not be determined.

For example, when at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body of the electrically-assisted traveling vehicle 10 (electric vehicle) measured by the measurement unit is equal to or less than the fifth threshold value, the determination unit 16a determines It is not necessary to cause the control unit 16 to perform the step overstepping control. Then, when at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body of the electrically assisted traveling vehicle 10 (electric vehicle) measured by the measurement unit is greater than the fifth threshold value, the determination unit 16a also The control unit 16 can be made to perform step overstep control.

In addition, the determination part 16a of the electrically-assisted traveling vehicle 10 (electric vehicle) may determine whether or not to cause the control part 16 to perform step overshooting control based on the vibration detected by the measurement part.

The determination unit 16a may not cause the control unit 16 to perform step overpass control when the representative value of the frequency spectrum of the vibration of the body of the electrically-assisted traveling vehicle 10 (electric vehicle) measured by the measurement unit is equal to or less than the sixth threshold value . In addition, when the representative value of the frequency spectrum of the vibration of the body of the electrically-assisted traveling vehicle 10 (electric vehicle) measured by the measurement unit is larger than the sixth threshold value, the determination unit 16a may cause the control unit 16 to perform step overriding control. . That is, the measurement unit may measure the frequency spectrum of the vibration of the vehicle body, and when the representative value (of the spectrum) measured by the measurement unit is larger than a threshold value (eighth threshold value), the determination unit 16a may estimate that the front wheel 12 is touching the step . In addition, when the representative value of the value (of the spectrum) measured by the measurement unit is equal to or smaller than the threshold (eighth threshold), the determination unit 16a may not estimate that the front wheel 12 has touched the step. In addition, the specific example of a representative value will be described later.

Generally speaking, it is known that the vibration generated when objects collide with each other depends on the rebound hardness of the objects. When the rebound hardness of the object is large, the frequency of vibration generated at the time of the collision increases. Thus, in the case where the frequency of the detected vibration is greater than the threshold value. It can be estimated that the electric-assisted traveling vehicle 10 (electric vehicle) collided with the step. In addition, when the frequency of the detected vibration is equal to or lower than the threshold value, it can be estimated that the electrically assisted traveling vehicle 10 collided with an object other than a step, or that the user performed a stop operation of the electrically assisted traveling vehicle 10 . As an example of the collision (or contact) with an object other than steps, a case where any part of the electrically assisted walking vehicle 10 (electric vehicle) comes into contact with another person's feet or luggage, etc. can be mentioned. However, the kinds of objects are not particularly limited.

The representative value of the spectrum may be the frequency of the largest peak in the spectrum, or may be a weighted average value of a plurality of peaks in the spectrum. In addition, it may be an intermediate frequency in the spectrum or an average frequency. That is, the calculation method of the representative value is not particularly limited.

When the front side of the electrically-assisted traveling vehicle 10 collides with an object such as a step, a force is applied in the front-rear direction of the vehicle body. Therefore, the vibration of the vehicle body of the electrically-assisted traveling vehicle 10 (electric vehicle) measured by the measuring unit may include vibration in the front-rear direction of the vehicle body. In addition, the direction of the vibration of the body of the electrically-assisted traveling vehicle 10 (electric vehicle) measured by the measuring unit of the electrically-assisted traveling vehicle 10 is not particularly limited.

The electrically-assisted traveling vehicle 10 (electric vehicle) may include a buffer member that covers at least a part of the front of the vehicle body or both side surfaces in the width direction of the vehicle body. When the frame of the electrically-assisted walking vehicle 10 (electric vehicle) collides with a relatively hard part of the human body that is close to the bone, such as the tibia, a large deceleration occurs, and the determination unit 16a may erroneously detect a step. Therefore, by providing the first buffer member on at least a part of the front or both side surfaces in the width direction of the electrically assisted traveling vehicle 10 (electric vehicle), it is possible to prevent a large deceleration from being detected when colliding with a human body.

FIG. 10 is a schematic diagram showing a configuration example in which a shock absorbing material is provided in front of the vehicle body. The duct frame 31 of the electrically-assisted traveling vehicle 10 of FIG. 10 protrudes forward of the vehicle body. Furthermore, a buffer member 81 is provided at the front end of the portion of the duct frame 31 that protrudes forward. Further, as examples of the buffer member 81, there are rubber, urethane foam, foamed resin, various springs, and the like, but the kind of the buffer member is not particularly limited. Here, FIG. 10 shows the structure of the duct frame 31 and the buffer member 81 on the left side of the electric-assisted traveling vehicle 10 . Similarly to the left side, the duct frame 31 on the right side of the electrically assisted traveling vehicle 10 may also include a buffer member 81 at the front end of the portion protruding forward. In addition, the structure provided in FIG. 10 is only an example. Therefore, the buffer member may be integrally formed, or may be attached to the electric-assisted traveling vehicle by a method different from that shown in FIG. 10 . In addition, the buffer member may be provided on at least a part of both side surfaces in the width direction of the electric-assisted traveling vehicle.

The step detection and step overtaking functions of the conventional walking assistance device are premised on the fact that the walking assistance device enters from a substantially front (substantially vertical direction) with respect to the step. Therefore, when the walking assist device enters at an angle with respect to the step, and the right front wheel and the left front wheel contact the step with a time difference, it is difficult to go over the step. Hereinafter, the step detection in the case where the walking assistance device enters so as to have an angle with respect to the step will be described.

FIG. 11 is a plan view of the electrically-assisted traveling vehicle 10 (electric vehicle) when viewed from above. In the plan view of FIG. 11 , the electric-assisted traveling vehicle 10 moves in the direction of the broken line P of the step 80 (the upper left direction in FIG. 11 ). That is, the dotted line P indicates the traveling direction of the electrically-assisted traveling vehicle 10 . Referring to FIG. 11 , it can be seen that since the step 80 exists in front of the broken line P, the electric-assisted traveling vehicle 10 enters in the direction in which the step 80 exists. In addition, when the electrically-assisted traveling vehicle 10 is turning, the traveling direction of the electrically-assisted traveling vehicle 10 changes depending on the time. Therefore, the broken line P can be said to indicate the direction of the speed vector of the electrically-assisted traveling vehicle 10 at a certain time.

The broken line S in FIG. 11 is a vertical line of the step 80 and indicates the front (vertical) direction of the step 80 . On the other hand, the dotted line P representing the traveling direction of the electric-assisted traveling vehicle 10 forms an angle θ with respect to the vertical line S of the step 80 . In this way, the electrically-assisted traveling vehicle 10 may enter not from the vertical direction of the step but at an angle with respect to the vertical direction. In addition, the step 80 may not necessarily be linear as in the example of FIG. 11 . For example, when the step is curved, the vertical line of the tangent to the step can be a vertical line.

As shown in FIG. 11 , when the electric-assisted traveling vehicle 10 enters at an angle with respect to the step 80 , either the front right wheel or the left front wheel collides with the step 80 first. It can be seen that in the example of FIG. 11 , the right front wheel of the electrically-assisted traveling vehicle 10 collides with the step 80 . Arrow a is a vector representing the acceleration applied to the vehicle body due to the collision of the right front wheel with the step 80 . In addition, the arrow 1 of the electrically-assisted traveling vehicle 10 represents the front-rear direction of the vehicle body, and the arrow w represents the width direction of the vehicle body. Referring to FIG. 11 , it can be seen that the acceleration vector a has a component in the front-rear direction l of the vehicle body and a component in the width direction w of the vehicle body.

Next, an example of the acceleration in the front-rear direction of the vehicle body and the acceleration in the width direction of the vehicle body detected by the electrically-assisted traveling vehicle 10 will be described.

FIG. 12 is a graph showing the difference in acceleration detected according to the collision of the front wheel. The horizontal axis of FIG. 12 represents the acceleration in the front-rear direction of the vehicle body. On the other hand, the vertical axis of FIG. 12 represents the acceleration in the width direction of the vehicle body. In the example of FIG. 12 , regarding the acceleration in the front-rear direction of the vehicle body, the acceleration in the front direction of the vehicle body is a positive value, and the acceleration in the front direction of the vehicle body is a negative value. In addition, regarding the acceleration in the width direction of the vehicle body, the acceleration in the right direction is assumed to be a positive value, and the acceleration in the left direction is assumed to be a negative value. The correspondence between the direction of acceleration and the positive and negative values shown here is an example, and a different correspondence may be used.

The graph of FIG. 12 shows that not only the acceleration in the front-rear direction of the vehicle body but also the acceleration in the width direction of the vehicle body is generated in the case where any one of the front wheels collides with the step. Acceleration in the left direction is detected when the right front wheel hits the step. On the other hand, the acceleration in the right direction is detected when the left front wheel collides with the step. Referring to the accelerations measured in the case where both front wheels collide with the step in the graph of FIG. 12 , it can be seen that the acceleration in the rear direction of the vehicle body tends to be larger than when either one of the front wheels collides with the step. . In addition, even when both front wheels collide with the step, acceleration in the width direction is detected. In addition, in the graph of FIG. 12 , the acceleration in the width direction detected when both the front wheels collide with the step is deviated to the right. It is presumed that the left front wheel is ahead of the right front wheel at the time of measurement. There are many cases of collision with steps.

From the results of FIG. 12 , it can be seen that which of the right front wheel and the left front wheel collided with the step can be estimated based on the direction of the detected acceleration in the width direction. That is, the acceleration measured by the measuring unit may include at least any one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the front-rear direction of the vehicle body of the electrically-assisted traveling vehicle 10 (electric vehicle), and the electrically-assisted traveling vehicle 10 (electric vehicle) acceleration in the width direction of the body of an electric vehicle). Then, the determination unit 16a can estimate which of the left and right wheels is touching the step based on the acceleration in the width direction of the body of the electrically-assisted traveling vehicle 10 (electric vehicle). That is, the determination unit 16a may estimate which of the front wheels is estimated to be in contact with the step based on the measurement value of the measurement unit.

In addition, the determination unit 16a can determine, based on the measurement value of the measurement unit, which one of the left front wheel and the right front wheel is in contact with the step (one-sided contact), or whether both the left front wheel and the right front wheel are in contact with the step (dual wheel touch). Thereby, the control of the vehicle body including the step overrunning operation can be performed according to the method of contacting the step (one-side contact or double-wheel contact). For example, the determination unit 16a can determine the one-sided contact and the two-wheel contact based on the acceleration in the width direction of the vehicle body and the acceleration in the front-rear direction of the vehicle body. For example, the determination unit 16a can determine that the one-sided contact is made when the acceleration in the vehicle body width direction is larger than the threshold value th _w . In addition, the determination unit 16a can determine that the two wheels are in contact when the acceleration in the front-rear direction of the vehicle body is larger than the threshold value th _fb . In addition, it may be determined that the two wheels are in contact when the acceleration in the vehicle body width direction is smaller than the threshold value th _w and the acceleration in the vehicle body front-rear direction is greater than the threshold value th _fb .

The measurement unit may measure at least any one of acceleration in the direction of decelerating the vehicle body, acceleration in the rearward direction of the vehicle body, and acceleration in the width direction of the vehicle body. When at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body measured by the measurement unit is equal to or greater than a predetermined threshold value (first threshold value), the determination unit 16a estimates the left front wheel and the right front wheel Which of the wheels touches the step. In addition, the measurement may be performed within a predetermined period after at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body measured by the measuring unit becomes equal to or greater than a predetermined threshold value (first threshold value) When the maximum value of the absolute value of the obtained acceleration in the width direction of the vehicle body is equal to or greater than a predetermined threshold value (second threshold value), the determination unit 16a estimates which of the left front wheel and the right front wheel is touching the step. Thereby, it is possible to discriminately determine that the left front wheel or the right front wheel is in contact with the step.

In addition, the acceleration in the width direction of the vehicle body used for the determination may be measured at the same timing as when the acceleration in the direction of decelerating the vehicle body or the acceleration in the rear direction of the vehicle body becomes equal to or greater than a threshold value (first threshold value), It can also be measured at different times. The control unit 16 can execute the step-over operation according to the result of the determination.

The control method of the electrically-assisted traveling vehicle 10 (electric vehicle) may include the step of measuring at least the first acceleration which is either one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the front-rear direction of the vehicle body, and the width of the vehicle body a second acceleration in a direction; estimating which of the left and right wheels is in contact with the step based on the measured first and second accelerations; and performing a step-over action corresponding to the wheel estimated to be in contact with the step.

In addition, the control program of the electrically-assisted traveling vehicle 10 (electric vehicle) may include the step of measuring at least the first acceleration which is either one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the front-rear direction of the vehicle body, and the vehicle body. a second acceleration in the width direction of the step; estimating which of the left and right wheels is in contact with the step based on the measured first and second accelerations; and performing a step-over action corresponding to the wheel estimated to be in contact with the step.

Here, the method of estimating the wheel touching the step by measuring the accelerations in multiple directions by the acceleration sensor 22a has been described, but the use of the speed value measured by the speed sensor 22b is not prohibited. For example, it can be estimated that there is contact with the step when the amount of decrease in the speed within a predetermined period is equal to or greater than the threshold value. In addition, the velocity sensor 22b may be used to measure velocity in a plurality of directions, or both velocity measurement and acceleration measurement may be performed. That is, the determination part 16a may estimate the front wheel which touched a step based on at least one of speed and acceleration. The front wheel touching the step may be only the left front wheel, only the right front wheel, or both the left front wheel and the right front wheel.

13 is a graph showing accelerations measured when the electric-assisted traveling vehicle 10 collides with a step while turning, and acceleration measured when the electrically-assisted traveling vehicle 10 collides with a step while traveling straight. The vertical axis of the graph of FIG. 13 represents the acceleration in the width direction of the vehicle body. On the other hand, the horizontal axis of the graph of FIG. 13 represents the acceleration in the front-rear direction of the vehicle body.

Referring to the graph of FIG. 13 , when only the acceleration in the front-rear direction of the vehicle body and the acceleration in the width direction of the vehicle body are referred to, the electric-assisted traveling vehicle 10 collides with a step while traveling straight, or the electrically-assisted traveling vehicle 10 collides while turning Getting to the steps doesn't have to be explicit.

Therefore, the former case and the latter case can be discriminated by using the information related to the rotation of the wheel together. For example, when the speed sensor 22b measures the rotational speed of the rear wheels, a value obtained by adding a negative sign to a value obtained by differentiating the rotational speed with time can be used as the deceleration (negative acceleration) of the rear wheels. . When the right front wheel collides with the step, the deceleration of the right rear wheel tends to be larger than the deceleration of the left rear wheel. Therefore, not only the acceleration in the front-rear direction of the vehicle body and the acceleration in the width direction of the vehicle body but also the deceleration of the right rear wheel and the deceleration of the left rear wheel can be used to estimate that the electric-assisted traveling vehicle 10 collides with a step while traveling straight or The electrically-assisted traveling vehicle 10 collides with a step while turning.

For example, when the rear wheel 13 includes a left rear wheel and a right rear wheel that are spaced apart in the width direction of the vehicle body, the measurement unit may calculate at least the acceleration in the rotational direction of the left rear wheel and the acceleration of the right rear wheel. The average value of the acceleration in the rotational direction, or the difference between the acceleration in the rotational direction of the left rear wheel and the acceleration in the rotational direction of the right rear wheel. In addition, when the front wheel 12 includes a left rear wheel and a right rear wheel that are separated in the width direction of the vehicle body, the measurement unit may calculate at least the acceleration in the rotational direction of the left front wheel and the acceleration of the right front wheel. The average value of the acceleration in the rotational direction, or the difference between the acceleration in the rotational direction of the left front wheel and the acceleration in the rotational direction of the right front wheel. This makes it possible to discriminately determine which one of the right front wheel and the left front wheel is in contact with the step.

The measurement unit may calculate an average value of the acceleration in the rotation direction of the left front wheel and the acceleration in the rotation direction of the right front wheel, or the average value of the acceleration in the rotation direction of the left rear wheel and the acceleration in the rotation direction of the right rear wheel. value as the first acceleration. In addition, the measurement unit may calculate the difference between the acceleration in the rotation direction of the left front wheel and the acceleration in the rotation direction of the right front wheel, or the difference between the acceleration in the rotation direction of the left rear wheel and the acceleration in the rotation direction of the right rear wheel. as the second acceleration. In this case, when the second acceleration is larger than the threshold value, it can be estimated that the electrically-assisted traveling vehicle 10 (electric vehicle) is making a turn. According to this method, it is also possible to discriminately determine which of the right front wheel and the left front wheel is in contact with the step.

Here, different threshold values may be used depending on the value of the first acceleration. For example, a larger threshold value can be used as the first acceleration becomes larger. As an example of the function of the threshold value, T=Σ(α _n a＾β _n )+γ can be cited, but a threshold value defined differently from these can also be used. Here, a is the acceleration of the vehicle body (first acceleration), and α _n and β _n are coefficients (positive real numbers) larger than 0. γ is an arbitrary coefficient. γ can be a positive real number, 0 or a negative real number.

The graph of FIG. 14 shows an example of the time waveform of the acceleration measured when the electric-assisted traveling vehicle 10 collides with the step. The horizontal axis of FIG. 14 represents the time, and the vertical axis represents the detected acceleration. In the graph of FIG. 14 , the measured values of the acceleration in a plurality of operation modes of the electrically-assisted traveling vehicle 10 are shown. 14 shows a waveform 90 measured when the electric-assisted traveling vehicle 10 collides from the front of a step, a waveform 91 measured when each of the front wheels of the electrically-assisted traveling vehicle 10 collides with the step at a shifted time, and The waveform 92 measured when the user performs the stop operation of the electrically assisted traveling vehicle 10 .

In the waveform 90, at time 0.0 seconds, the electric-assisted traveling vehicle 10 collided with the step, and a large impact was applied compared with other waveforms, and a large acceleration was detected. On the other hand, in the waveform 91 , the front wheels collide with the step at a time-shifted time, so the impact is dispersed into a plurality of times, and the magnitude of the detected acceleration peak is smaller than that of the waveform 90 . In the waveform 92 , the electric-assisted traveling vehicle 10 did not collide with the step, and the user manually stopped the electrically-assisted traveling vehicle 10 . Therefore, the magnitude of the peak value of the acceleration detected in the waveform 92 is smaller than that in the waveform 91 .

The threshold value used when detecting the collision with the step needs to be determined in consideration of the acceleration detected in each operation mode illustrated in FIG. 14 . For example, when the threshold value is set based on the peak value of the acceleration (for example, waveform 90 ) detected when the electric-assisted traveling vehicle 10 collides from the front of the step, the threshold value is too large, and therefore, the timing of each front wheel of the electrically-assisted traveling vehicle 10 is shifted. In the case of collision with a step (for example, waveform 91 ), there is a possibility that the step cannot be detected. On the other hand, when the threshold value is set too small, there is a possibility that a step may be erroneously detected when the user manually stops the electric-assisted traveling vehicle 10 .

Therefore, in order to improve the accuracy of the step detection by the electrically-assisted traveling vehicle 10, the threshold value can be used separately according to the conditions. For example, when it is estimated by the above-described method whether or not the electric-assisted traveling vehicle 10 is turning, and it is estimated that the electric-assisted traveling vehicle 10 is turning, a different threshold or threshold value may be used from the case where the electrically-assisted traveling vehicle 10 is traveling straight. function. That is, when the maximum value of the absolute value of the acceleration in the width direction of the body of the electrically-assisted traveling vehicle 10 (electric vehicle) measured by the measurement unit is equal to or greater than a predetermined threshold (second threshold), the determination unit 16a may set the The threshold value (fifth threshold value) of the acceleration as a condition for performing the step-overrunning operation is set to be small. Here, as an example of the acceleration, the acceleration in the direction of decelerating the vehicle body or the acceleration in the rearward direction of the vehicle body of the electrically-assisted traveling vehicle 10 (electric vehicle) measured by the measurement unit can be cited. However, it is also possible to determine whether or not the step-over-stepping operation can be performed based on other accelerations. In addition, the threshold value may be selected from any of a plurality of fixed values, or may be a function using the speed of the vehicle body as a parameter.

Referring to the waveform 91 of FIG. 14 showing the acceleration measured when the front wheels of the electric-assisted walking vehicle 10 collide with the step at a time-staggered time, there are acceleration peaks at time 0.0 second and time 0.6 second. The acceleration at the peak detected initially (time 0.0 seconds) is greater than the acceleration at the peak detected later (time 0.6 seconds). At each peak it is estimated that the front wheels on different sides are in contact with the step. It is considered that since the kinetic energy of the electrically assisted traveling vehicle 10 is reduced by the first contact with the step, the acceleration detected when the second contact is made with the step becomes small. Therefore, when each of the front wheels of the electrically-assisted traveling vehicle 10 collides with a step at a time-shifted time, a different threshold value can be used according to the number of collisions.

For example, when the electric-assisted traveling vehicle 10 enters at an angle with respect to the step, and the right front wheel and the left front wheel are in contact with the step at different timings, if it is detected that either of the front wheels is in contact with the step, the use of A threshold value smaller than the threshold value used for the detection of the first contact with the step is used as a threshold value for detecting the contact of the other front wheel with the step. That is, the measuring unit measures at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body, and in the direction of decelerating the vehicle body of the electrically-assisted traveling vehicle 10 (electric vehicle) measured by the measuring unit When at least one of the acceleration in the rearward direction of the vehicle body and the acceleration in the rearward direction of the vehicle body is equal to or greater than a threshold value (third threshold value) smaller than the first threshold value, the determination unit 16a may estimate that both the left front wheel and the right front wheel are touching the step.

Thus, by using an excessively small threshold value, it is possible to prevent the occurrence of erroneous detection of a step in a situation other than a collision with a step, such as when the electrically-assisted traveling vehicle 10 is manually stopped.

In addition, when the electrically-assisted traveling vehicle 10 collides with a step, the peak value of the acceleration in the width direction of the vehicle body may be measured later than the peak value of the acceleration in the front and rear direction of the vehicle body. Therefore, after the acceleration in the direction of decelerating the vehicle body or the acceleration in the rearward direction of the vehicle body of the electrically-assisted traveling vehicle 10 (electric vehicle) measured by the measuring unit becomes equal to or greater than the first threshold value, the electric power When the maximum value of the absolute value of the acceleration in the width direction of the vehicle body of the assisting vehicle 10 (electric vehicle) is equal to or greater than the second threshold value, the determination unit 16a may estimate which of the left and right wheels is touching the step. As an example of the above-mentioned predetermined period, there is 10 milliseconds, but a value different from this may be used.

(Crossing the steps)

Next, the step-over-stepping operation by the electrically-assisted traveling vehicle (electric vehicle) will be described.

FIG. 15 is a plan view showing a first example of an electric-assisted traveling vehicle that enters a step at an angle with respect to the step. Hereinafter, with reference to FIG. 15 , description will be given of the overtaking operation of the step 80 when the electrically-assisted traveling vehicle 10 enters so as to have an angle with respect to the step 80 . When an angle of 0 degrees or more is formed between the vector (dotted line P) related to the traveling direction of the electric-assisted traveling vehicle 10 and the vertical line (dotted line S) of the step 80 , the electrically-assisted traveling vehicle 10 is angled with respect to the step 80 . way to enter. In FIG. 15 , the right front wheel of the electrically-assisted traveling vehicle 10 is in contact with the step 80 . The determination unit 16a detects the collision of the right front wheel with the step based on the measurement value of the measurement unit.

In FIG. 15 , the blank arrows indicate the driving force d _pl of the left rear wheel and the driving force d _pr of the right rear wheel, respectively. In the example of FIG. 15 , when it is assumed that the driving force d _pl of the left rear wheel and the driving force d _pr of the right rear wheel are set to be equal, the force in the direction perpendicular to the step 80 is the driving force d _pl and the driving force d pl of the right rear wheel. Sin(90-theta) times the resultant force of the force d _pr . Therefore, the larger the angle θ is, the more difficult it is for the electrically-assisted traveling vehicle 10 to go over the step 80 . Therefore, when turning the body of the electrically-assisted traveling vehicle 10 and the step 80 is moved over, a larger force is applied in the direction perpendicular to the step 80 .

For example, as in the example of FIG. 15 , the control unit 16 can control the drive unit so that the driving force d _pl of the left rear wheel is larger than the driving force d _pr of the right rear wheel. As a result, a force for turning the body of the electrically-assisted traveling vehicle 10 in the right direction acts, and the step 80 can be crossed at a smaller angle θ. In this way, the control unit 16 may cause the drive unit of at least one of the front wheel 12 and the rear wheel 13 located on the opposite side of the front wheel 12 estimated to be in contact with the step in the width direction of the vehicle body to generate a driving force, The driving force is greater than the driving force of at least one of the driving portion of the front wheel 12 on the side estimated to be in contact with the step and the rear wheel 13 on the same side as the front wheel 12 in the width direction of the vehicle body.

In addition, the control unit 16 may generate driving force only for the drive unit of at least one of the front wheel 12 and the rear wheel 13 on the opposite side of the front wheel 12 estimated to be in contact with the step in the width direction of the vehicle body. That is, the driving force of at least one of the drive unit of the front wheel 12 and the rear wheel 13 on the opposite side to the front wheel 12 estimated to be in contact with the step in the width direction of the vehicle body may be greater than the driving force estimated to be in contact with the step. The driving force to at least one of the drive unit of the front wheel 12 on the step and the rear wheel 13 located on the same side as the front wheel 12 in the width direction of the vehicle body. Thereby, after any one of the left front wheel and the right front wheel touches the step, the electrically-assisted traveling vehicle 10 can be made to face the step. Further, the wheel on the side touching the step can be estimated using the method described in the above-mentioned description of the step detection process.

In addition, when the electrically-assisted traveling vehicle 10 enters so as to have an angle with respect to the step 80 , it is not necessary to generate a driving force for turning the body of the electrically-assisted traveling vehicle 10 . For example, the control unit 16 may generate the driving force only for the drive unit of the rear wheel 13 located on the same side as the front wheel 12 estimated to be in contact with the step in the width direction of the vehicle body. In addition, the control unit 16 may control the driving force of at least one of the driving unit of the front wheel 12 on the side estimated to be in contact with the step and the rear wheel 13 on the same side as the front wheel 12 in the width direction of the vehicle body. The driving force is larger than the driving force of at least one of the front wheel 12 on the side estimated to be in contact with the step and the rear wheel 13 on the same side as the front wheel 12 in the width direction of the vehicle body. According to these methods, it is possible to make the electric-assisted traveling vehicle 10 face the step after either the left front wheel or the right front wheel touches the step. For example, when the step to be crossed is not high, or when the step is inclined (inclined), the step can sometimes be crossed without a large driving force. In this case, the step-over-step control may be performed after the electric-assisted traveling vehicle 10 is turned, and the step-over-step control accompanying the turning of the electrically-assisted traveling vehicle 10 may not be performed. Thereby, since control is simplified, the user can go over the steps in a shorter period of time.

FIGS. 16 and 17 are plan views showing a second example of the electric-assisted traveling vehicle that entered at an angle with respect to the step. 16 and 17 show each step of the operation of the electrically-assisted traveling vehicle 10 . Hereinafter, the operation of the electrically-assisted traveling vehicle 10 will be described with reference to FIGS. 16 and 17 .

Initially, the electric-assisted traveling vehicle 10 travels so as to have an angle θ greater than 0 degrees with respect to the step 80 (step S1 ). At the time point of step S1, the driving force d _pl of the left rear wheel is equal to the driving force d _pr of the right rear wheel. In this case, d _pl >0, d _pr >0, or d _pl =d _pr =0 may be used. In the case of d _pl =d _pr =0, the user moves the electrically-assisted traveling vehicle 10 forward without using an assist force.

As a result of the advance of the electrically assisted traveling vehicle 10 according to step S1, the right front wheel touches the step 80 (step S2). The determination unit 16a detects the collision of the right front wheel with the step 80 based on the measurement value of the measurement unit. Then, the control unit 16 controls the drive unit to set the driving force d _pr of the right rear wheel in the traveling direction, which is the wheel estimated to be in contact with the step 80 , to zero. In addition, the control unit 16 may control the braking unit to apply the brake to the right rear wheel. At this time, the driving force of the left rear wheel, which is the wheel on the side estimated not to be in contact with the step 80 , is set to d _pl >0. Therefore, the electrically-assisted traveling vehicle 10 starts to turn in the right direction (direction change).

In this way, the control unit 16 may generate driving force only for the drive unit of either the front wheel or the rear wheel located in the width direction of the vehicle body on the opposite side to the front wheel estimated to be in contact with the step. Thereby, the vehicle body can be turned in a short time after any one of the front wheels comes into contact with the step.

As a result of turning the electrically-assisted traveling vehicle 10 to the right, the left front wheel of the other front wheel 12 comes into contact with the step 80 (step S3). At this time, the electrically-assisted traveling vehicle 10 faces substantially the front of the step 80 . That is, the above-mentioned angle θ is substantially equal to 0 degrees. The smaller the angle θ is, the smaller the driving force of the electric-assisted traveling vehicle 10 can be over the step 80 . Therefore, the electrically-assisted traveling vehicle 10 may start the operation of passing over the step 80 according to the timing of step S3. That is, if it is estimated that both the front wheels are in contact with the step, the control unit 16 may perform a step overrunning operation. Thereby, since the electrically-assisted traveling vehicle 10 can take a more stable posture, the step 80 can be passed over without performing complicated control.

For example, when the determination unit 16a estimates that both the front wheels 12 are in contact with the step based on the measurement value of the measurement unit, the control unit 16 may place the two sides in the width direction of the body of the electrically-assisted traveling vehicle 10 (electric vehicle) The driving force of the drive unit of at least one of the front wheel and the rear wheel is set to be equal. Thereby, the driving force of the drive unit can be adjusted so that the amount of turning of the electrically-assisted traveling vehicle 10 is not too large. Since the assistance is performed at a stage where the front surface of the electrically-assisted traveling vehicle 10 faces substantially the front of the step 80 , there is an advantage that the step 80 can be passed over more reliably.

Furthermore, the timing at which the left front wheel and the right front wheel (both front wheels) come into contact with the step is not particularly limited. For example, the left front wheel and the right front wheel may contact the step at substantially the same time, or the timing at which the left front wheel contacts the step and the timing at which the right front wheel contacts the step may be staggered. In addition, the control method of the driving force after the start of the overrunning operation of the step 80 will be described later.

Then, in step S4, the electric-assisted traveling vehicle 10 performs the operation of passing over the step 80. As shown in FIG. In step S4, the driving force of the driving force d _pr of the right rear wheel and the driving force d _pl of the left rear wheel is made larger than these driving forces before step S3 to assist the overstepping of the step 80 .

Next, an example of a wheel control method when the electrically-assisted traveling vehicle 10 enters so as to have an angle with respect to the step will be described. 18 and 19 are graphs showing an example of a method of controlling the wheels of the electrically-assisted traveling vehicle 10 (electric vehicle). The horizontal axis of FIGS. 18 and 19 represents time. On the other hand, the vertical axis of FIGS. 18 and 19 represents the driving force of the wheels.

The broken line c1 in FIG. 18 represents the driving force of the driving unit connected to the wheel on the opposite side to the side estimated to be in contact with the step. On the other hand, the dotted line c2 represents the driving force of the driving portion connected to the wheel on the side estimated not to be in contact with the step. For example, assuming a case where the electric-assisted traveling vehicle 10 having the configuration shown in FIGS. 1 and 2 is used and the right front wheel touches the step first, the broken line c1 corresponds to the drive unit of the drive unit connected to the right rear wheel. On the other hand, the broken line c2 corresponds to the drive part of the drive part connected to the left rear wheel. the following. The control shown in FIG. 18 will be described by taking the case where the right front wheel touches the step first as an example.

Before time t1, the electrically-assisted traveling vehicle 10 moves forward, and the driving force d _pl of the left rear wheel and the driving force d _pr of the right rear wheel are set to be equal. In addition, in the example of FIG. 18, d _pl >0 and d _pr >0 before time t1, but d _pl =0 and d _pr =0 may be satisfied.

Then, at time t1, the right front wheel of the electrically-assisted traveling vehicle 10 touches the step. The determination unit 16a estimates that the right front wheel collided with the step based on the measurement value of the measurement unit. Then, the control unit 16 determines that a step has been detected at time t1, and increases the driving force d _pl of the left rear wheel and the driving force d _pr of the right rear wheel after time t1. Here, the rate of increase per unit time of the driving force d _pl of the drive unit connected to the wheel on the side estimated to be in contact with the step (here, the left rear wheel) is set to be greater than that of the wheel estimated to be not in contact with the step. The rate of increase per unit time of the driving force d _pr of the drive unit connected to the wheel on the side of the step (here, the right rear wheel).

Then, at time t2, the driving force _dpl of the left rear wheel with the larger increase rate per unit time of the driving force reaches the target value. Here, the target value may or may not be the maximum driving force of the drive unit. The control unit 16 maintains the drive force d _pl of the left front wheel after the time t2 at the target value. On the other hand, at time t2, the driving force d _pr of the right rear wheel, which has a smaller increase rate per unit time of the driving force, has not yet reached the target value. The control unit 16 also increases the driving force d _pr of the right rear wheel after the next time t2.

At time t3, the driving force d _pr of the right rear wheel with a small increase rate per unit time of the driving force also reaches the target value. Then, the control unit 16 maintains the drive force d _pl of the left front wheel after the time t3 at the target value.

For example, the control unit 16 maintains the driving force d _pl of the left front wheel and the driving force d _pr of the right rear wheel at the target values until it is determined that the electrically-assisted traveling vehicle 10 has successfully passed the step. The control unit 16 can, for example, determine whether or not the electric-assisted traveling vehicle 10 has successfully climbed over a step based on the measurement value of the inclination detection sensor 23 , but the method of determining whether or not the step has been successfully climbed is not particularly limited. As described in FIG. 7 described above, when it is determined that the electrically-assisted traveling vehicle 10 has successfully passed the step, the control unit 16 can reduce the driving force d _pl of the left front wheel and the driving force d _pr of the right rear wheel.

Referring to FIG. 18 , between time t1 and time t3 , the relationship of d _pl >d _pr is established, and the state in which the driving force of the left front wheel is greater than the driving force of the right rear wheel continues. Therefore, it is possible to turn the vehicle body to the right while the vehicle body of the electrically-assisted traveling vehicle 10 climbs the steps. Thereby, after going over the step, the orientation (angle θ) of the vehicle body of the electrically-assisted traveling vehicle 10 is corrected, and the user can enter the step with a safer posture.

The broken line c3 in FIG. 19 represents the driving force of the driving part connected to the wheel on the opposite side to the side estimated to be in contact with the step. On the other hand, the broken line c4 represents the driving force of the driving part connected to the wheel on the side estimated not to be in contact with the step. For example, assuming that the electric-assisted traveling vehicle 10 having the configuration shown in FIGS. 1 and 2 is used and the right front wheel touches the step first, the broken line c3 corresponds to the drive unit of the drive unit connected to the right rear wheel. On the other hand, the broken line c4 corresponds to the drive part of the drive part connected to the left rear wheel. the following. The control in FIG. 19 will be described by taking the case where the right front wheel touches the step first as an example.

Then, at time t1, the right front wheel of the electrically-assisted traveling vehicle 10 touches the step. The determination unit 16a estimates that the right front wheel collided with the step based on the measurement value of the measurement unit. Then, the control unit 16 determines that a step has been detected at time t1, and increases the driving force d _pl of the left rear wheel and the driving force d _pr of the right rear wheel after time t1. Here, the increase rate per unit time of the driving force d _pl of the driving unit that is also connected to the wheel estimated to be in contact with the side of the step (here, the left rear wheel) is set to be greater than the rate of increase per unit time that is estimated to be in contact with the wheel. The rate of increase per unit time of the drive force d _pr of the drive unit connected to the wheel on the side of the step (here, the right rear wheel).

The increase rate per unit time of the driving force d _pr of the right rear wheel is set to a fixed value, whereas the increase rate per unit time of the driving force d _pl of the left rear wheel decreases as time elapses. Therefore, the inclination of the broken line c4 after the time t1 is smooth.

At time t3, either the driving force of the driving force d _pr of the right rear wheel and the driving force of the driving force d _pl of the left rear wheel reaches the target value. The target value may or may not be the maximum driving force of the drive unit. Then, the control unit 16 maintains the driving force d _pr of the right rear wheel and the driving force d _pl of the left rear wheel at the target values after time t3 .

For example, the control unit 16 maintains the driving force d _pl of the left front wheel and the driving force d _pr of the right rear wheel at the target values until it is determined that the electrically-assisted traveling vehicle 10 has successfully passed the step. The control unit 16 can, for example, determine whether or not the electric-assisted traveling vehicle 10 has successfully climbed over a step based on the measurement value of the inclination detection sensor 23 , but the method of determining whether or not the step has been successfully climbed is not particularly limited. As described in FIG. 7 described above, when it is determined that the electrically-assisted traveling vehicle 10 has successfully passed the step, the control unit 16 can reduce the driving force d _pl of the left front wheel and the driving force d _pr of the right rear wheel.

Referring to FIG. 19 , between time t1 and time t3, the relationship of d _pl >d _pr is established, and the state in which the driving force of the left front wheel is greater than the driving force of the right rear wheel continues. Therefore, it is possible to turn the vehicle body to the right while the vehicle body of the electrically-assisted traveling vehicle 10 climbs the steps. As a result, after the step has been crossed, the orientation (angle θ) of the vehicle body of the electrically-assisted traveling vehicle 10 is corrected, and the user can enter the step with a safer posture.

As exemplified in the control methods of FIGS. 18 and 19 , the control unit 16 may make at least one of the front wheel 12 and the rear wheel 13 on the opposite side of the front wheel 12 estimated to be in contact with the step in the width direction of the vehicle body and the rear wheel 13 The driving force of any one of the driving parts and the driving force of at least one of the front wheel 12 estimated to be in contact with the step and the rear wheel 13 located on the same side as the front wheel 12 in the width direction of the vehicle body are increased. to a predetermined threshold (fourth threshold or target value). Thereby, the vehicle body can be prevented from turning excessively.

In the methods of FIGS. 18 and 19 , between time t1 and time t3 , a driving force is also applied to the rear wheel estimated to collide with the step (closer to the step). Therefore, it is possible to climb the steps using the two rear wheels while turning the body of the electrically-assisted traveling vehicle 10 . In the methods of FIGS. 18 and 19 , in the transition period (times t1 to t3 ) before the driving forces of the two rear wheels reach the target value, there is a difference in the driving forces of the left and right rear wheels, and the electric assist can be smoothly corrected The direction of the vehicle body of the traveling vehicle 10 .

In addition, in the methods of FIGS. 18 and 19 , after detecting that the other front wheel has contacted the step, the driving forces of the two rear wheels may be set to be equal. Thereby, when both the left front wheel and the right front wheel are in contact with the step, the step can be climbed with a large driving force (for example, the driving force of the above-mentioned target value).

As described above, the overtaking operation performed by the control unit 16 may include an operation of causing the drive unit to increase the driving force of the wheels while turning the body of the electrically-assisted traveling vehicle 10 (electric vehicle), and causing the electrically-assisted traveling vehicle 10 (electric vehicle) to increase the driving force of the wheels. Either an operation of causing the drive unit to increase the driving force of the wheels after the body of the vehicle is turned, or an operation of increasing the driving force of the wheels by the drive unit.

(Use of double casters)

As shown in the plan view of FIG. 20 , the electric-assisted traveling vehicle 10 (electric vehicle) may enter the step 80 in a state where the rotation direction of the front wheel 12 and the rotation direction of the rear wheel 13 are different. For example, when the electrically-assisted traveling vehicle 10 performs a direction change (turning) while moving, the front wheels 12 may face in a direction different from the traveling direction of the vehicle body of the electrically-assisted traveling vehicle 10 .

20 is a plan view showing a first example of the case where the front wheels have an angle with respect to the traveling direction of the vehicle body. In step S10 of FIG. 20 , the two front wheels 12 (left front wheel and right front wheel) of the electrically-assisted traveling vehicle 10 collide with the step 80 . Each of the front wheels 12 receives resistances F _nl and F _nr from the step 80 as a reaction to the driving force (d _pl +d _pr ) of the rear wheels 13 . The resistance forces F _nl and F _nr become moments with respect to the rotation center 12r of each of the front wheels 12, and the front wheels 12 are rotated counterclockwise (left-hand rotation).

By turning, the front wheel 12 becomes the direction in which the side surface is substantially parallel to the step 80 (step S11 ). In step S11 , the rotatable direction of the front wheel 12 is a direction substantially parallel to the step 80 . Since the front wheel 12 cannot turn in the direction of the step 80 , even if it is assisted by the driving force (d _pl , d _pr ) of the rear wheel 13 , it is difficult for the electrically-assisted traveling vehicle 10 to go over the step 80 .

In addition, in the example of FIG. 20 , the traveling direction of the vehicle body of the electrically-assisted traveling vehicle 10 is substantially perpendicular to the step 80, but the problem shown here also occurs when the vectors in the traveling direction of the vehicle body of the electrically-assisted traveling vehicle 10 are relative to each other. In the case where the vertical line of the step 80 has an angle θ (θ>0 degrees).

The wheels of the electrically-assisted traveling vehicles in the above-mentioned examples all have single-wheel tires. However, the wheels of the electrically-assisted walking vehicle need not necessarily be single-wheeled tires. For example, the front wheels 12 (the right front wheel and the left front wheel) of the electrically-assisted traveling vehicle 10a of FIG. 21 are casters 12a configured to be able to turn.

21 is a plan view showing a second example of the case where the front wheels have an angle with respect to the traveling direction of the vehicle body. In step S20 of FIG. 21 , the casters 12 a on both sides of the front of the electrically-assisted traveling vehicle 10 a collide with the step 80 . Each of the casters 12a receives resistances F _nl and F _nr from the step 80 as a reaction to the driving force (d _pl +d _pr ) of the rear wheel 13 . The resistance forces F _nl and F _nr become moments with respect to the rotation center 12r of each tandem caster 12a, and each tandem caster 12a rotates clockwise (right rotation).

The width of the entire wheel of the caster 12a is larger than the width of the entire wheel of the front wheel 12 of FIG. 20 . Therefore, the contact surface of the caster of the caster 12a is made substantially parallel to the step 80 by the rotation (step S21). Therefore, the electrically-assisted traveling vehicle 10a can get over the step 80 with the assistance of the driving force (d _pl , d _pr ) of the rear wheel 13 .

As shown in the example of FIG. 21 , the front wheels of the electrically-assisted traveling vehicle (electric vehicle) may be 2-wheel casters configured to be rotatable with respect to the vertical axis. In addition, it is not necessary to use casters as the front wheels of the electrically-assisted traveling vehicle (electric vehicle). For example, it is possible to use a tire having a larger tire width than the rear wheel as the front wheel, thereby reducing the probability of a state in which it is difficult to move the vehicle body forward as shown in FIG. 20 .

(Step detection when using twin casters)

As a front wheel of an electrically assisted traveling vehicle (electric vehicle), when a caster is used, the collision between the wheel and the step may be multi-stage. 22 and 23 are plan views showing examples of collisions between the electric-assisted traveling vehicle 10a and the steps. Hereinafter, the multi-stage collision with the step will be described with reference to FIGS. 22 and 23 .

In the examples of FIGS. 22 and 23 , the electric-assisted traveling vehicle 10a enters so as to have an angle θ with respect to the step 80 (θ>0 degrees). That is, the vertical line of the step 80 forms an angle θ with the traveling direction of the electric-assisted traveling vehicle 10a. Each of the casters 12a attached to the front side of the electrically-assisted traveling vehicle 10a has an angle with respect to the traveling direction of the electrically-assisted traveling vehicle 10a. In addition, the directions of the left and right casters 12a are different.

Referring to step S30, when comparing the magnitudes of the angles with respect to the traveling direction of the electric assist traveling vehicle 10a, the angle of the right caster 12a is larger than that of the left caster 12a. First, in step S30 , one end of the right caster 12 a collides with the step 80 . The determination part 16a detects the collision of the right side caster 12a and a step based on the measurement value of a measurement part. Thereby, the control part 16 determines that it is necessary to turn in the right direction of the electrically-assisted traveling vehicle 10a. Then, the control unit 16 controls the driving unit to set the driving force d _pl of the left rear wheel to be larger than the driving force d _pr of the right rear wheel. Therefore, in step S30, the electric-assisted traveling vehicle 10a starts to turn right.

In the next step S31 , one end of the left caster 12 a collides with the step 80 . The determination part 16a may detect the collision of the left caster 12a and a step based on the measurement value of a measurement part. When the collision is detected, the control unit 16 may determine that the direction of the vehicle body has been changed, and may set the difference between the driving force d _pl of the left rear wheel and the driving force d _pr of the right rear wheel to be smaller than before. the difference. In addition, the control unit 16 may not change the driving force d _pl of the left rear wheel and the driving force d _pr of the right rear wheel in step S31 . Regardless of the driving force d _pl of the left rear wheel and the driving force d _pr of the right rear wheel, the electrically-assisted traveling vehicle 10a continues to turn right in step S31.

Then, in step S32 , the other end of the right caster 12 a collides with the step 80 . The determination part 16a may detect the collision of the right side caster 12a and a step based on the measurement value of a measurement part. When the collision is detected, the control unit 16 may determine that the direction of the vehicle body has been changed, and may set the difference between the driving force d _pl of the left rear wheel and the driving force d _pr of the right rear wheel to be smaller than before. the difference. In addition, the control unit 16 may not change the driving force d _pl of the left rear wheel and the driving force d _pr of the right rear wheel in step S32 . Regardless of the driving force d _pl of the left rear wheel and the driving force d _pr of the right rear wheel, the electrically-assisted traveling vehicle 10a continues to turn right in step S31.

Finally, in step S33 , the other end of the dual-wheel caster 12 a of the left dual-wheel collides with the step 80 . The determination part 16a detects the collision of the right side caster 12a and a step based on the measurement value of a measurement part. As a result, since the front surface of the electrically-assisted traveling vehicle 10a faces substantially the front of the step 80, the control unit 16 determines that it is not necessary to turn the electrically-assisted traveling vehicle 10a to the right. The control unit 16 controls the driving unit to set the driving force d _pl of the left rear wheel and the driving force d _pr of the right rear wheel to the same value. Here, the driving force d _pl of the left rear wheel and the driving force d _pr of the right rear wheel may be set to the above-described target values in FIGS. 18 and 19 .

After step S33, the electrically-assisted traveling vehicle 10a can go over the step 80 with the assistance of the driving force d _pl of the left rear wheel and the driving force d _pr of the right rear wheel.

In the example of FIG. 22 and FIG. 23 mentioned above, the caster 12a with two wheels is shifted in time and collides with the step many times. Therefore, the shock applied to the electrically-assisted traveling vehicle 10a is dispersed into a plurality of times. Therefore, there is a possibility that the acceleration detected by the acceleration sensor 22a is smaller than the case where a single-wheel tire is used for the front wheel. Similarly, in the case of detecting a collision using the speed sensor 22b, there is a possibility that the change in speed in one collision is smaller than that in the case where a single-wheel tire is used for the front wheel. Therefore, when the front wheels of the electrically assisted traveling vehicle (electric vehicle) use casters, the value of the threshold value used for the detection of the collision with the step can be set to be smaller than that in the case where the front wheels are single-wheel tires value of . Thereby, detection of a step can be performed.

(Second Embodiment)

Next, a second embodiment of the present disclosure will be described. The second embodiment shown in FIGS. 24 to 30 is different from the above-described first embodiment in the structures around the rear wheel 13 and the motor 20 , and other structures are the same as the above-described first embodiment. In FIGS. 24 to 30 , the same reference numerals are assigned to the same parts as those of the first embodiment, and detailed descriptions are omitted.

In the configuration shown in FIGS. 24 to 28 , the motor 20 of the electrically-assisted traveling vehicle 10 is connected to each of the rear wheels 13 via the planetary gear mechanism 50 .

As shown in FIGS. 26 to 28 , the motor 20 includes a casing 61 fixed to the duct frame 31 , an output shaft support 62 accommodated in the casing 61 and rotatable with respect to the casing 61 , and a support fixed to the output shaft The output shaft 63 rotates integrally with the output shaft support portion 62 . Among them, a flange 64 is fixed to the casing 61 , and the output shaft 63 protrudes from the center of the casing 61 . A bearing 65 is provided between the housing 61 and the output shaft support portion 62 . In addition, a magnet 66 is provided on the outer periphery of the output shaft support portion 62 . Further, a coil 67 is arranged around the magnet 66 , and the coil 67 is fixed to the case 61 . Electric power from the battery 21 is supplied to the coil 67, and the output shaft support portion 62 provided with the magnet 66 rotates. Moreover, the cap 68 is provided in the center part of the case 61 .

The rear wheel 13 includes a rim 71 , a tire 72 provided on the outer periphery of the rim 71 , and a rim pressure plate 73 coupled to the rim 71 . The rim 71 is fixed to the bearing 75 provided around the flange 64 via the pressure plate 74 .

The planetary gear mechanism 50 includes a sun gear 51, an internal gear 52 arranged around the sun gear 51, three planetary gears 53 that mesh with the sun gear 51 and the internal gear 52 and revolve while rotating when the output shaft 63 rotates, and The planetary carrier 54 to which the three planetary gears 53 are rotatably supported and the revolving motion of the planetary gears 53 is transmitted.

Among them, the sun gear 51 is connected to the output shaft 63 of the motor 20 , and can rotate with the rotation of the output shaft 63 . In addition, the internal gear 52 is connected to the rim 71 of the rear wheel 13 . The carrier 54 is connected to the flange 64 of the motor 20 , and is fixed to the duct frame 31 via the flange 64 and the housing 61 .

Next, in the present embodiment, the operation when the motor 20 is controlled to lift the front wheel 12 relative to the rear wheel 13 (rear wheel support) will be described.

First, it is assumed that the electric-assisted traveling vehicle 10 moves in a normal state without the front wheel 12 hitting the step. In this case, the assist force from the output shaft 63 of the motor 20 is transmitted from the sun gear 51 connected to the output shaft 63 of the motor 20 to the internal gear 52 via the planetary gears 53 , and then to the internal gear 52 connected to the internal gear 52 . 13 rear wheels. Thereby, the movement of the rear wheel 13 is assisted by the motor 20 . At this time, the duct frame 31 connected to the planet carrier 54 does not rotate.

Here, when the numbers of teeth of the sun gear 51 and the inner gear 52 are respectively Za and Zc (Za<Zc), and the angular velocities of the sun gear 51 , the inner gear 52 and the carrier 54 are respectively Wa, Wc and Wx, The following formula (1) holds.

Zc(Wc-Wx)=-Za(Wa-Wx)... Formula (1)

When the electric-assisted traveling vehicle 10 is moving in the normal state, the carrier 54 is fixed, and therefore Wx is zero. Therefore, the following formula (2) holds.

Wc=(-Za/Zc)Wa... Formula (2)

That is, the rotational speed of the output shaft 63 from the motor 20 is decelerated to -Za/Zc times and transmitted.

On the other hand, when the front wheel 12 of the electrically-assisted traveling vehicle 10 collides with the step, the front wheel 12 is locked, so that the rear wheel 13 does not rotate. At this time, the ring gear 52 of the planetary gear mechanism 50 connected to the rear wheel 13 is also locked. On the other hand, the rotational force from the output shaft 63 is transmitted to the sun gear 51 connected to the output shaft 63 of the motor 20 . This rotational force is transmitted from the sun gear 51 to the planetary carrier 54 via the planetary gears 53 , and the rotational force acts in the direction of the arrow M (see FIG. 25 ) with respect to the pipe frame 31 connected to the planetary carrier 54 (the same as that of the electric-assisted traveling vehicle 10 ). the opposite direction of travel).

Therefore, when the front wheel 12 hits the step, the motor 20 is controlled by the control unit 16 , so that the electric assist traveling vehicle 10 can be rotated as a whole to raise the front wheel 12 to a position higher than the rear wheel 13 . In this case, the control unit 16 may control to increase the output of the motor 20 in accordance with, for example, an operating force (grip force) applied to the handle 14 . Specifically, the motor 20 is controlled so that the output of the motor 20 is relatively large (that is, the proportional coefficient of the motor output to the operating force is increased) even if the operating force is the same as that in the normal state, and the This makes it possible to lift the front wheel 12 to a position higher than the rear wheel 13 .

In this way, when the front wheel 12 of the electrically-assisted traveling vehicle 10 collides with the step, the internal gear 52 is fixed, and therefore Wc is 0 in the above formula (1). Therefore, the following formula (3) holds.

Wx={Za/(Zc+Za)}Wa... Equation (3)

That is, the rotational speed of the output shaft 63 from the motor 20 is decelerated to Za/(Zc+Za) times, and the entire electric-assisted traveling vehicle 10 connected to the carrier 54 receives the rotational force in the opposite direction of travel (the side where the front wheels 12 are suspended). .

As described above, according to the present embodiment, the motor 20 is connected to the rear wheel 13 via the planetary gear mechanism 50 . Thereby, when the front wheel 12 of the electrically-assisted traveling vehicle 10 collides with the step, the planetary gear mechanism 50 can be used to lift the front wheel 12 to a position higher than the rear wheel 13 . That is, the control unit 16 can rear-wheel support the front wheels 12 with respect to the rear wheels 13 by the reaction of the planetary gear mechanism 50 by the driving force of the motor 20 .

Further, according to the present embodiment, the planetary gear mechanism 50 includes the sun gear 51 connected to the output shaft 63 of the motor 20 , the internal gear 52 arranged around the sun gear 51 , and the sun gear 51 and the internal gear 52 that mesh with the sun gear 51 and the internal gear 52 and output When the shaft 63 rotates, the planetary gear 53 revolves while rotating, and the planetary gear 54 rotatably supports the planetary gear 53 and transmits the revolving motion of the planetary gear 53. The internal gear 52 is connected to the rear wheel 13, and the planetary carrier 54 is fixed. on the duct frame 31. As a result, when the front wheel 12 collides with the step, the rotational force from the output shaft 63 of the motor 20 is transmitted from the sun gear 51 to the carrier 54 via the planetary gears 53 , and the rotational force can act on the pipe frame connected to the carrier 54 . 31. Thereby, the electric-assisted traveling vehicle 10 can be rotated as a whole, and the front wheels 12 can be raised relative to the rear wheels 13 .

In the present embodiment, the case where the control unit 16 uses the planetary gear mechanism 50 to lift the front wheel 12 relative to the rear wheel 13 has been described as an example, however, it is not limited to the planetary gear mechanism 50, and an eccentric reduction gear may be used. etc., a mechanism with a gear that revolves while rotating.

Alternatively, a mechanism including two gears may be used instead of the planetary gear mechanism 50 . Specifically, as shown in FIGS. 29 and 30 , the first gear 57 and the motor 20 may be directly connected, and the second gear 58 and the rear wheel 13 may be directly connected, so that the first gear 57 and the second gear 57 may be directly connected to the rear wheel 13 . The gears 58 mesh with each other. As shown in FIG. 29 , during normal running, the motor 20 is used to assist the movement of the rear wheels 13 to electrically assist the traveling vehicle 10 to run. On the other hand, as shown in FIG. 30 , for example, when the front wheel 12 hits a step and the front wheel 12 is locked, the rear wheel 13 is also locked. When the motor 20 is further rotated in this state, a force is generated to lift the entire electric-assisted traveling vehicle 10 . At this time, the force action of turning is performed in the direction opposite to the traveling direction of the electric-assisted traveling vehicle 10 . Thereby, the front wheel 12 of the electrically-assisted traveling vehicle 10 can easily go over the steps.

(third embodiment)

Next, a third embodiment of the present disclosure will be described. The third embodiment shown in FIGS. 31 and 32 is different from the above-described first embodiment in that a drive unit that generates a driving force for raising the front wheel 12 is provided independently of the motor 20 , and the other structures are the same as those of the above-described first embodiment. One embodiment is the same. In FIGS. 15 and 16 , the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed descriptions are omitted.

In FIGS. 31( a ) and 31 ( b ), the drive unit that generates the driving force for raising the front wheels 12 includes an additional motor 46 that is different from the motor 20 . In this case, the rotational axis of the additional motor 46 may be provided on the same axis as the rotational axis of the rear wheel 13 ( FIG. 31( a )), or may be provided on a different axis from the rotational axis of the rear wheel 13 ((b) of FIG. 31 ).

In FIGS. 32( a ) and 32 ( b ), the drive unit that generates the driving force for raising the front wheel 12 includes an actuator 47 that is different from the motor 20 . The actuator 47 is connected to the frame 11 . In this case, the actuator 47 may be a telescopic type actuator that lifts the front wheel 12 relative to the rear wheel 13 by expanding and contracting ( FIG. 32( a )), or may be a telescopic actuator that swings the front wheel 12 . A swing-type actuator that lifts the wheel 12 with respect to the rear wheel 13 ( FIG. 32( b )).

In addition, in FIGS. 31 and 32, the motor 20 need not necessarily be provided.

(Fourth Embodiment)

Next, a fourth embodiment of the present disclosure will be described using FIGS. 33 and 34 . In FIGS. 33 and 34 , the same reference numerals are assigned to the same parts as those of the first to third embodiments, and detailed descriptions are omitted.

FIG. 33 is a schematic perspective view showing an example of the appearance of the electrically-assisted traveling vehicle (electric vehicle) 10 of the present embodiment.

(Structure of Electric Assisted Walking Vehicle)

As shown in FIG. 33 , the electrically-assisted traveling vehicle 10 includes a frame 11 , a pair of front wheels 12 and a pair of rear wheels (wheels) 13 provided on the frame 11 , and a pair of handles 14 connected to the frame 11 .

A motor 20 for assisting the movement of the corresponding rear wheel 13 is connected to each of the pair of rear wheels 13 . The battery 21 and the control unit 16 are attached to the frame 11 , respectively. In addition, the control unit 16 is provided with an inclination detection sensor 23 .

In the present embodiment, a pair of handles 14 to be operated by the user are provided at the upper ends of the pair of left and right duct frames 31 . The pair of handles 14 are connected to each other by handles 17 extending in the horizontal direction. In addition, the pair of handles 14 and the handle 17 are substantially U-shaped. Furthermore, the pair of handles 14 is equipped with an arm support portion 27 on which the user's elbow can be placed. A hole is provided in the arm support portion 27 so that each handle 14 can be inserted, and the handle 14 can be attached to the hole.

A sheet portion 37 on which a user can sit is provided between the pair of left and right duct frames 31 as needed.

The battery 21 supplies electric power to each element of the motor 20 , the control unit 16 , and the like, and the electrically-assisted traveling vehicle 10 . The battery 21 is provided below the sheet portion 37 between the pair of duct frames 31 .

In addition, a speed sensor (an example of a component related to the measurement unit) 22 b is provided on each of the pair of rear wheels 13 . In addition, the speed sensor 22b is not limited to being incorporated in the pair of front wheels 12 and/or the pair of rear wheels 13, and may be attached to other arbitrary members such as the frame 11 and the pair of handles 14. Alternatively, the speed sensor 22b may be arranged in the vicinity of the control unit 16 . In addition, in the present embodiment, the traveling speed of the electrically-assisted traveling vehicle 10 is determined based on the rotational speed of the rear wheels 13 , but it is not limited to this, and may be determined based on the rotational speed of the front wheels 12 or the front wheels 12 and the rear wheels 13 . Judging by the rotational speed of both sides.

The measurement unit may include an acceleration sensor 22a. In this case, the acceleration sensor 22 a directly measures the acceleration of the electrically-assisted traveling vehicle 10 without using the rotational acceleration of the rear wheel 13 , and transmits a signal of the acceleration to the control unit 16 . Then, the control unit 16 calculates the speed by integrating the acceleration.

In addition, the measurement unit may include GPS (Global Positioning System). In this case, the GPS detects the position of the electrically-assisted traveling vehicle 10 without using the rotational acceleration of the rear wheels 13 . Then, the control unit 16 may calculate the speed of the electrically-assisted traveling vehicle 10 by differentiating the position information from the GPS, and calculate the acceleration by quadratic differentiation of the position information from the GPS.

The tilt detection sensor 23 includes acceleration sensors of two or more axes. The tilt detection sensor 23 is provided in the vicinity of the control unit 16 . Alternatively, the inclination detection sensor 23 may be provided on the upper portion of the electrically-assisted traveling vehicle 10 . In addition, as the tilt detection sensor 23 , a gyro sensor may be used instead of an acceleration sensor, and the posture of the electrically-assisted traveling vehicle 10 may be estimated.

In addition, the other structure of the electrically-assisted traveling vehicle 10 is the same as that of the electrically-assisted traveling vehicle 10 ( FIGS. 1 and 2 ) in the first embodiment.

In addition, in the present embodiment, a grip sensor, a strain sensor, a proximity sensor, a pressure sensor, or the like that directly detects whether the user is gripping the pair of handles 14 is not provided in the electrically-assisted traveling vehicle 10 . However, the present invention is not limited to this, and the grip sensor 24 may be provided in the handle 14 in the same manner as the electric-assisted traveling vehicle 10 ( FIGS. 1 and 2 ) in the first embodiment.

Each embodiment and each modification of the present disclosure have been described above, but each embodiment and each modification are given as examples and are not intended to limit the scope of the present invention. Each embodiment and each modification can be implemented in various other forms, and various omissions, substitutions, and changes can be made without departing from the gist of the invention. Each embodiment and each modification are included in the scope and gist of the present invention, and similarly, are also included in the invention described in the claims and the scope of their equivalents.

Description of reference numerals

10, 10a: Electric assisted walking vehicle; 11: Frame; 12: Front wheel; 13: Rear wheel; 14: Handle; 15: Brake unit; 16: Control part; 20: Motor; 21: Battery; 22a: Acceleration sensor; 22b: speed sensor; 23: tilt detection sensor; 24: grip sensor; 25: foot detection sensor; 31: pipe frame.

Claims (37)

1. An electric vehicle comprising: a drive unit that drives a wheel provided on the vehicle body including at least one of a front wheel and a rear wheel; a control unit that controls the driving unit to make the wheel go over a step of the step; a measurement unit that measures at least one of a speed and an acceleration applied to the vehicle body on which the wheel is provided; and A determination unit that determines whether or not to cause the control unit to perform step overstep control based on the measurement value of the measurement unit. 2. The electric vehicle of claim 1, wherein, When the determination unit determines that the front wheel is in contact with a step based on the measurement value of the measurement unit, the control unit is caused to perform control over the step. 3. The electric vehicle of claim 1 or 2, wherein, The step overshooting control includes control for increasing the driving force of the driving unit for driving the wheel. 4. The electric vehicle of any one of claims 1 to 3, wherein, The control for passing the step includes control for turning the vehicle body. 5. The electric vehicle of any one of claims 1 to 4, wherein, The control over the step includes control for increasing the driving force while turning the vehicle body. 6. The electric vehicle of claim 2, wherein, The front wheel includes a left front wheel and a right front wheel that are disposed apart from each other in the width direction of the vehicle body, The determination section determines which of the left front wheel and the right front wheel is in contact with the step based on the measurement value of the measurement section. 7. The electric vehicle of claim 6, wherein, The measurement unit measures at least one of an acceleration in a direction in which the vehicle body is decelerated, an acceleration in a front-rear direction of the vehicle body, and an acceleration in the width direction of the vehicle body. 8. The electric vehicle of claim 7, wherein, The rear wheel includes a left rear wheel and a right rear wheel that are disposed apart from each other in the width direction of the vehicle body, The measurement unit calculates at least an average value of the acceleration in the rotation direction of the left rear wheel and the acceleration in the rotation direction of the right rear wheel, or the acceleration in the rotation direction of the left rear wheel and the right rear wheel. The difference in acceleration in the direction of rotation of the wheel. 9. An electric vehicle according to claim 7 or 8, wherein, The measuring unit calculates at least an average value of the acceleration in the rotation direction of the left front wheel and the acceleration in the rotation direction of the right front wheel, or the acceleration in the rotation direction of the left front wheel and the right front wheel. The difference in acceleration in the direction of rotation of the wheel. 10. The electric vehicle of any one of claims 6 to 9, wherein, The measurement unit measures at least one of an acceleration in a direction in which the vehicle body is decelerated, an acceleration in a rearward direction of the vehicle body, and an acceleration in the width direction of the vehicle body, The determination unit estimates that the left front Which of the wheel and the right front wheel touches the step. 11. An electric vehicle according to any one of claims 6 to 10, wherein, The measurement unit measures at least one of an acceleration in a direction in which the vehicle body is decelerated, an acceleration in a rearward direction of the vehicle body, and an acceleration in the width direction of the vehicle body, After at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body measured by the measuring unit becomes equal to or greater than a first threshold value, the When the maximum value of the absolute value of the acceleration in the width direction of the vehicle body is equal to or greater than a second threshold value, the determination unit estimates which of the left front wheel and the right front wheel is in contact with the step. 12. An electric vehicle according to claim 10 or 11, wherein, The measurement unit measures at least one of an acceleration in a direction in which the vehicle body is decelerated and an acceleration in a rearward direction of the vehicle body, The determination unit estimates that the left Both the front wheel and the right front wheel are in contact with the step, and the third threshold is smaller than the first threshold. 13. The electric vehicle of any one of claims 6 to 12, wherein, The control unit generates a driving force only for the drive unit of the rear wheel located on the same side as the front wheel estimated to be in contact with the step in the width direction of the vehicle body. 14. The electric vehicle of any one of claims 6 to 13, wherein, The control unit drives only at least one of the front wheel and the rear wheel located on the opposite side of the front wheel that is estimated to be in contact with the step in the width direction of the vehicle body. Department generates driving force. 15. The electric vehicle of any one of claims 6 to 14, wherein, The control unit causes the drive unit of at least one of the front wheel and the rear wheel to be located in the width direction of the vehicle body on the opposite side to the front wheel that is estimated to be in contact with the step. generating a driving force greater than at least either one of the front wheel on the side estimated to be in contact with the step and the rear wheel on the same side of the front wheel in the width direction of the vehicle body the driving force of the driving part. 16. The electric vehicle of any one of claims 6 to 15, wherein, The control unit drives at least one of the front wheel on the side estimated to be in contact with the step and the rear wheel on the same side in the width direction of the vehicle body to drive the drive unit The force is greater than the drive portion of at least any one of the front wheel on the side estimated to be in contact with the step and the rear wheel on the same side as the front wheel in the width direction of the vehicle body of the driving force. 17. An electric vehicle according to any one of claims 6 to 16, wherein, The control unit causes the drive unit of at least one of the front wheel and the rear wheel to be located in the width direction of the vehicle body on the opposite side to the front wheel that is estimated to be in contact with the step. and the drive part of at least one of the front wheel estimated to be in contact with the step and the rear wheel located on the same side as the front wheel in the width direction of the vehicle body The driving force of is incremented to a fourth threshold. 18. The electric vehicle of claim 17, wherein, The driving force of the driving portion of at least one of the front wheel and the rear wheel on the opposite side of the front wheel estimated to be in contact with the step in the width direction of the vehicle body The drive is greater than the drive of the drive unit of at least one of the front wheel estimated to be in contact with the step and the rear wheel located on the same side as the front wheel in the width direction of the vehicle body force. 19. The electric vehicle of any one of claims 1 to 18, wherein, When the determination unit estimates that both the front wheels are in contact with the step based on the measurement value of the measurement unit, the control unit causes the front wheels and the front wheels on both sides in the width direction of the vehicle body to be The driving force of the drive unit of at least one of the rear wheels is equal. 20. The electric vehicle of any one of claims 1 to 19, wherein, When the maximum value of the absolute value of the acceleration in the width direction of the vehicle body measured by the measurement unit is equal to or greater than a second threshold value, the control unit sets, as a condition for executing the step-over operation, The fifth threshold value of acceleration is set small. 21. The electric vehicle of any one of claims 1 to 20, wherein, As the speed of the vehicle body measured by the measurement unit increases, the control unit sets a sixth threshold value of the absolute value of the acceleration as a condition for executing the step-over operation to be larger. 22. The electric vehicle of claim 2, wherein, The measurement unit measures at least one of an acceleration in a direction in which the vehicle body is decelerated and an acceleration in a rearward direction of the vehicle body, When at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body measured by the measurement unit is greater than a seventh threshold value, the determination unit estimates that the front wheel touch the steps. 23. The electric vehicle of claim 22, wherein, When at least one of the acceleration in the direction of decelerating the vehicle body and the acceleration in the rearward direction of the vehicle body measured by the measurement unit is equal to or less than the seventh threshold value, the determination unit does not estimate that the The front wheel touches the step. 24. An electric vehicle according to claim 22 or 23, wherein, including a storage unit that stores the measurement value of the measurement unit, The determination unit adjusts the seventh threshold based on the measurement value stored in the storage unit. 25. The electric vehicle of claim 24, wherein, After the control unit causes the front wheel to go over the step, the determination unit detects an acceleration smaller than the seventh threshold within a predetermined period before the control unit performs the step-over control of the front wheel , the determination unit changes the seventh threshold to a smaller value. 26. An electric vehicle according to claim 24 or 25, wherein, When the acceleration measured by the measurement unit when the control unit moves the front wheel over a step is larger than the seventh threshold value, and the difference between the acceleration and the seventh threshold value is larger than a predetermined value, The determination unit changes the seventh threshold value to a larger value. 27. The electric vehicle of claim 2, wherein, The measuring section measures the frequency spectrum of the vibration of the vehicle body, When the representative value of the values measured by the measurement unit is larger than the eighth threshold value, the determination unit estimates that the front wheel is in contact with a step. 28. The electric vehicle of claim 27, wherein, When the representative value of the value measured by the measurement unit is equal to or less than the predetermined eighth threshold value, the determination unit does not estimate that the front wheel is in contact with the step. 29. An electric vehicle according to claim 27 or 28, wherein, The vibration of the vehicle body includes vibration in the front-rear direction of the vehicle body. 30. The electric vehicle of any one of claims 1 to 29, wherein, A buffer member is provided which covers the front of the vehicle body or at least a part of both side surfaces in the width direction of the vehicle body. 31. The electric vehicle of any one of claims 1 to 30, wherein, The front wheel is a two-wheel caster configured to be able to turn. 32. An electric vehicle having: a drive unit that drives a wheel including at least one of a front wheel and a rear wheel; a control unit that controls the drive unit to perform step overstep control; a measurement unit that measures at least one of a speed and an acceleration applied to the vehicle body on which the wheel is provided; and a determination unit that determines, based on the measurement value of the measurement unit, whether to cause the control unit to perform step overstep control, When the determination unit determines that the front wheel is in contact with a step based on the measurement value of the measurement unit, the control unit performs control to increase the driving force of the drive unit for driving the wheel or to cause the Control of the body turning. 33. A control method for an electric vehicle, comprising the steps of: measuring at least either of velocity and acceleration applied to the vehicle body; and Based on at least one of the speed and the acceleration, it is determined whether or not to perform step overshoot control. 34. The control method for an electric vehicle according to claim 33, further comprising the steps of: determining whether the front wheel is in contact with a step based on at least one of the speed and the acceleration; and The step overrunning control is performed when it is estimated that the front wheel is in contact with the step. 35. The control method of an electric vehicle according to claim 33 or 34, wherein, The step overshooting control includes at least one of control for increasing the driving force for driving the wheels, control for turning the vehicle body, and control for increasing the driving force while turning the vehicle body. 36. A control program for an electric vehicle, comprising the steps of: measuring at least one of the velocity and acceleration applied to the vehicle body; determining whether the front wheel is in contact with a step based on at least one of the speed and the acceleration; and The step overrunning control is performed when it is estimated that the front wheel is in contact with the step. 37. The control program for an electric vehicle according to claim 36, wherein, The step overshooting control includes at least one of control for increasing the driving force for driving the wheels, control for turning the vehicle body, and control for increasing the driving force while turning the vehicle body.

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