JP5617650B2 - vehicle - Google Patents

Description

  The present invention relates to a vehicle having at least a pair of left and right wheels.

  In recent years, in view of the problem of depletion of energy resources, there has been a strong demand for fuel saving of vehicles. On the other hand, the number of vehicle owners is increasing due to the low price of vehicles, and one person tends to own one vehicle. Therefore, for example, there is a problem that energy is wasted when only one driver drives a four-seater vehicle. The most efficient way to save fuel consumption by reducing the size of the vehicle is to configure the vehicle as a one-seater tricycle or four-wheel vehicle.

  However, depending on the running state, the stability of the vehicle may decrease. Therefore, a technique for improving the stability of the vehicle during turning by tilting the vehicle body in the lateral direction has been proposed (for example, see Patent Document 1).

JP 2005-88742 A

  However, in the conventional vehicle, in order to improve the turning performance, the vehicle body can be tilted inward in the turning direction, but the operation of tilting the vehicle body is difficult and the turning performance is low. , Passengers may feel uncomfortable or anxious.

  The present invention solves the problems of the conventional vehicle, controls the tilt angle of the vehicle body so that the centrifugal force to the outside of the turn and the gravity are balanced, and the range in which the position of the center of gravity can be controlled. If the vehicle is off the road, the lateral acceleration component is zero, even when the posture of the vehicle changes or when the road surface is inclined to the left or right, by stopping the operation of tilting the vehicle. Since a force in a direction parallel to the longitudinal axis of the vehicle body acts on the vehicle body and the occupant, the stability of the vehicle body can be maintained, turning performance can be improved, and the occupant feels uncomfortable An object of the present invention is to provide a highly safe vehicle that has a good ride comfort and can realize a stable running state.

  Therefore, in the vehicle according to the present invention, a vehicle body including a steering unit and a drive unit coupled to each other, and a wheel rotatably attached to the steering unit, the steering wheel steering the vehicle body, A wheel rotatably attached to the drive unit, the drive wheel for driving the vehicle body, a plurality of sensors for detecting lateral acceleration and longitudinal acceleration acting on the vehicle body, and the steering unit or the drive unit. A link mechanism for inclining in the turning direction, an inclining actuator device for operating the link mechanism, and a control device for controlling the inclining of the vehicle body by controlling the inclining actuator device. In addition to performing tilt control based on the lateral acceleration detected by multiple sensors, the center of gravity position is outside the controllable range based on the lateral acceleration and longitudinal acceleration detected by the multiple sensors. Whether the judged, when the gravity center position is out of the controllable range stops the operation of inclining the vehicle body.

  According to the configuration of the first aspect, when the running state becomes unstable due to factors such as a sudden change in the shape of the road surface, it is possible to effectively prevent the running state from becoming further unstable. A vehicle with higher safety can be provided.

  According to the configuration of the second aspect, it is possible to appropriately determine that the running state has become unstable.

  According to the structure of Claim 3 and 4, the link mechanism which inclines a vehicle body to right and left can be fixed reliably.

It is a right view which shows the structure of the vehicle in embodiment of this invention. It is a figure which shows the structure of the link mechanism of the vehicle in embodiment of this invention. It is a figure explaining the inclination operation | movement of the vehicle body at the time of turning driving | running | working in embodiment of this invention. It is a figure explaining the operation | movement which returns the vehicle body in an embodiment from the inclination state to an upright state. It is a figure explaining the acceleration which acts on the gravity center of the vehicle body in embodiment of this invention. It is a block diagram which shows the structure of the vehicle body tilt control system in embodiment of this invention. It is a figure which shows the dynamic model explaining the inclination operation | movement of the vehicle body at the time of turning driving | running | working in embodiment of this invention. It is a flowchart which shows the operation | movement of the lateral acceleration calculation process in embodiment of this invention. It is a flowchart which shows the operation | movement of the inclination control process of the vehicle in embodiment of this invention. It is a flowchart which shows the operation | movement of the link motor control process in embodiment of this invention. It is a flowchart which shows the operation | movement of the link brake control process in embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a right side view showing a configuration of a vehicle in an embodiment of the present invention, FIG. 2 is a diagram showing a configuration of a link mechanism of the vehicle in the embodiment of the present invention, and FIG. 3 is a turn in the embodiment of the present invention. FIG. 4 is a diagram for explaining the tilting operation of the vehicle body during traveling, FIG. 4 is a diagram for explaining the operation of returning the vehicle body from the tilted state to the upright state in the embodiment of the present invention, and FIG. It is a figure explaining the acceleration which acts on a gravity center. 3A is a rear view in an upright state, FIG. 3B is a rear view in an inclined state, FIG. 4A is a diagram for explaining an operation in a normal state, and FIG. FIG. 5A is a top view and FIG. 5B is a right side view.

  In the figure, reference numeral 10 denotes a vehicle according to the present embodiment, which includes a main body 20 as a vehicle body drive unit, a riding unit 11 as a steering unit on which an occupant gets on and steer, and a center in the width direction in front of the vehicle body. The wheel 12F is a front wheel disposed as a steering wheel, and the left wheel 12L and the right wheel 12R are drive wheels disposed rearward as rear wheels. Furthermore, the vehicle 10 operates as a lean mechanism for leaning the vehicle body from side to side, that is, as a lean mechanism, that is, a vehicle body tilt mechanism, supporting the left and right wheels 12L and 12R, and the link mechanism 30. And a link motor 25 as a tilt actuator device. The vehicle 10 may be a three-wheeled vehicle with two front wheels on the left and right and one wheel on the rear, or may be a four-wheeled vehicle with two wheels on the left and right. As shown in the figure, a case will be described in which the front wheel is a single wheel and the rear wheel is a left and right tricycle.

  When turning, the angle of the left and right wheels 12L and 12R with respect to the road surface 18, that is, the camber angle is changed, and the vehicle body including the riding portion 11 and the main body portion 20 is inclined toward the turning inner wheel, thereby improving turning performance and the occupant. It is possible to ensure the comfort of the car. That is, the vehicle 10 can tilt the vehicle body in the lateral direction (left and right direction). In the example shown in FIGS. 2 and 3 (a), the left and right wheels 12L and 12R are upright with respect to the road surface 18, that is, the camber angle is 0 degree. In the example shown in FIG. 3B, the left and right wheels 12L and 12R are inclined in the right direction with respect to the road surface 18, that is, a camber angle is given.

  The link mechanism 30 includes a left vertical link unit 33L that supports a left wheel 12L and a left rotation driving device 51L including an electric motor that applies driving force to the wheel 12L, a right wheel 12R, and the wheel 12R. A right vertical link unit 33R that supports a right rotation drive device 51R composed of an electric motor or the like that applies a driving force to an upper side, and an upper horizontal link unit 31U that connects the upper ends of the left and right vertical link units 33L and 33R; The lower horizontal link unit 31D that connects the lower ends of the left and right vertical link units 33L and 33R, and the central vertical member 21 that has an upper end fixed to the main body 20 and extends vertically. The left and right vertical link units 33L and 33R and the upper and lower horizontal link units 31U and 31D are rotatably connected. Further, the upper and lower horizontal link units 31U and 31D are rotatably connected to the central vertical member 21 at the center thereof. When the left and right wheels 12L and 12R, the left and right rotational drive devices 51L and 51R, the left and right vertical link units 33L and 33R, and the upper and lower horizontal link units 31U and 31D are described in an integrated manner, The rotation drive device 51, the vertical link unit 33, and the horizontal link unit 31 will be described.

  The rotary drive device 51 as a drive actuator device is a so-called in-wheel motor, and a body as a stator is fixed to the vertical link unit 33 and is a rotor attached to the body so as to be rotatable. A rotating shaft is connected to the shaft of the wheel 12, and the wheel 12 is rotated by the rotation of the rotating shaft. The rotational drive device 51 may be a motor other than an in-wheel motor.

  The link motor 25 is a rotary electric actuator including an electric motor or the like, and includes a cylindrical body as a stator and a rotating shaft as a rotor rotatably attached to the body. The body is fixed to the main body portion 20 via the mounting flange 22, and the rotating shaft is fixed to the lateral link unit 31 </ b> U on the upper side of the link mechanism 30. The rotation axis of the link motor 25 functions as an inclination axis for inclining the main body 20 and is coaxial with the rotation axis of the connecting portion between the central vertical member 21 and the upper horizontal link unit 31U. When the link motor 25 is driven to rotate the rotation shaft with respect to the body, the upper horizontal link unit 31U rotates with respect to the main body 20 and the central vertical member 21 fixed to the main body 20, The link mechanism 30 operates, that is, bends and stretches. Thereby, the main-body part 20 can be inclined. Note that the rotation axis of the link motor 25 may be fixed to the main body 20 and the central vertical member 21, and the body may be fixed to the upper horizontal link unit 31U.

  The link motor 25 includes a link angle sensor (not shown) that detects a change in the link angle of the link mechanism 30. The link angle sensor is a rotation angle sensor that detects the rotation angle of the rotation shaft with respect to the body in the link motor 25, and includes, for example, a resolver, an encoder, and the like. As described above, when the link motor 25 is driven to rotate the rotation shaft with respect to the body, the upper horizontal link unit 31U rotates with respect to the main body 20 and the central vertical member 21 fixed to the main body 20. Therefore, a change in the angle of the upper horizontal link unit 31U relative to the central vertical member 21, that is, a change in the link angle can be detected by detecting the rotation angle of the rotation shaft with respect to the body.

  Further, the link motor 25 includes a link brake 26 as a link lock mechanism that fixes the rotation shaft to the body so as not to rotate. The link brake 26 is released when power is supplied, for example, a non-excitation operation type electromagnetic brake, or a mechanical mechanism, and the rotation shaft is fixed to the body so as not to rotate. It is desirable that no power be consumed between them. The link brake 26 can fix the rotation shaft so as not to rotate at a predetermined angle with respect to the body, and fix the link mechanism 30 so as not to bend and stretch.

  The riding part 11 is connected to the front end of the main body part 20 via a connecting part (not shown). The connecting part may have a function of connecting the riding part 11 and the main body part 20 so as to be relatively displaceable in a predetermined direction.

  The boarding part 11 includes a seat 11a, a footrest 11b, and a windbreak part 11c. The seat 11 a is a part for a passenger to sit while the vehicle 10 is traveling. The footrest 11b is a part for supporting the occupant's foot, and is disposed on the front side (right side in FIG. 1) and below the seat 11a.

  Further, a battery device (not shown) is disposed behind or below the riding section 11 or on the main body section 20. The battery device is an energy supply source for the rotation drive device 51 and the link motor 25. In addition, a control device, an inverter device, various sensors, and the like (not shown) are accommodated in the rear portion or the lower portion of the riding portion 11 or in the main body portion 20.

  A steering device 41 is disposed in front of the seat 11a. The steering device 41 is provided with members necessary for steering such as a handle bar 41a as a steering device, a meter such as a speed meter, an indicator, and a switch. The occupant operates the handle bar 41a and other members to instruct the traveling state of the vehicle 10 (for example, traveling direction, traveling speed, turning direction, turning radius, etc.). As a steering device that is a means for outputting the required turning amount of the vehicle body requested by the occupant, other devices such as a steering wheel, a jog dial, a touch panel, and a push button are used instead of the handlebar 41a as the steering device. It can also be used as

  The wheel 12F is connected to the riding section 11 via a front wheel fork 17 that is a part of a suspension device (suspension device). The suspension device is a device similar to a suspension device for front wheels used in, for example, general motorcycles, bicycles, and the like, and the front wheel fork 17 is, for example, a telescopic type fork with a built-in spring. As in the case of a general motorcycle, bicycle, etc., the wheel 12F as the steered wheel changes the steering angle in accordance with the operation of the handlebar 41a by the occupant, thereby changing the traveling direction of the vehicle 10.

Specifically, the handle bar 41a is connected to the upper end of a steering shaft member (not shown), and the upper end of the front wheel fork 17 is connected to the lower end of the steering shaft member. The steering shaft member is rotatably attached to a frame member (not shown) included in the riding section 11 in a state where the steering shaft member is inclined obliquely so that the upper end is located behind the lower end. The distance between the left and right wheels 12L and 12R axle is the axle and the rear wheel of the wheel 12F is a front wheel, i.e., the wheel base is L _H.

  Further, a vehicle speed sensor 54 as vehicle speed detecting means for detecting a vehicle speed that is the traveling speed of the vehicle 10 is disposed at the lower end of the front wheel fork 17 that supports the axle of the wheel 12F. The vehicle speed sensor 54 is a sensor that detects the vehicle speed based on the rotational speed of the wheel 12F, and includes, for example, an encoder.

  In the present embodiment, the vehicle 10 includes a first lateral acceleration sensor 44a, a second lateral acceleration sensor 44b, a first longitudinal acceleration sensor 44c, and a second longitudinal acceleration sensor 44d. The first lateral acceleration sensor 44a, the second lateral acceleration sensor 44b, the first longitudinal acceleration sensor 44c, and the second longitudinal acceleration sensor 44d are sensors including a general acceleration sensor, a gyro sensor, and the like. Acceleration, that is, acceleration in the lateral direction (horizontal direction in FIG. 3) as the width direction of the vehicle body and longitudinal acceleration of the vehicle 10, that is, acceleration in the longitudinal direction of the vehicle body (lateral direction in FIG. 1) are detected.

  As shown in FIG. 3 (b), the vehicle 10 stabilizes the vehicle body by tilting the vehicle body toward the inside of the turn when turning, so that the centrifugal force to the outside of the turn at the time of turning and the gravity are balanced by inclining the vehicle body. It is controlled so that it becomes such an angle. By performing such control, for example, even if the road surface 18 is inclined in a direction perpendicular to the traveling direction (left and right direction with respect to the traveling direction), the vehicle body can always be kept horizontal. As a result, the vehicle body and the occupant are apparently always subjected to gravity downward in the vertical direction, the sense of incongruity is reduced, and the stability of the vehicle 10 is improved. However, if such control is performed when the traveling state becomes unstable due to factors such as a sudden change in the shape of the road surface 18, the traveling state may be further unstable.

  For example, when the turn is finished, as shown in FIG. 4 (a), the link mechanism 30 is operated so as to lower the right wheel 12R and raise the left wheel 12L. -1) is returned to the posture shown in FIG. 4A-2 from the posture in which the vehicle body is tilted to the right. However, for example, during high speed traveling, a protrusion is present on a part of the road surface 18, and immediately after only the left wheel 12L passes over the protrusion, as shown in FIG. The left wheel 12L floats in the air, and the vehicle body is inclined to the right. In this state, if the link mechanism 30 is operated as in the case shown in FIG. 4 (a), the entire vehicle body is raised as shown in FIG. It may become stable.

  Therefore, in the present embodiment, when the control of tilting the vehicle body is performed, the operation of tilting the vehicle body is stopped when the traveling state may be further unstable. Specifically, in the present embodiment, the lateral acceleration of the tilted vehicle body is detected by the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b attached to the vehicle body, and the detected lateral acceleration is detected. Feedback control is performed so that it becomes zero. As a result, the vehicle body can be tilted to an inclination angle at which the centrifugal force acting during turning and gravity are balanced. Further, even when the road surface 18 is inclined in a direction perpendicular to the traveling direction, the vehicle body can be controlled to have an inclination angle that makes the vehicle body vertical. The first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b are disposed so as to be positioned on the center in the width direction of the vehicle body, that is, on the longitudinal axis of the vehicle body. At the same time, the longitudinal acceleration of the vehicle body is detected by the first longitudinal acceleration sensor 44c and the second longitudinal acceleration sensor 44d attached to the vehicle body, and the center of gravity position of the vehicle 10 can be controlled based on the detected longitudinal acceleration. When it is determined that the vehicle is out of the predetermined range, that is, the stable range, the operation of tilting the vehicle body is stopped. This can effectively prevent the running state from becoming more unstable.

  By the way, if the lateral acceleration of the vehicle body, that is, the lateral acceleration is detected with only one lateral acceleration sensor, an unnecessary acceleration component may also be detected. For example, while the vehicle 10 is traveling, only one of the left and right wheels 12L and 12R may fall into the depression on the road surface 18. In this case, since the vehicle body is tilted, the lateral acceleration sensor is displaced in the circumferential direction and detects the acceleration in the circumferential direction. That is, an acceleration component that is not directly derived from centrifugal force or gravity, that is, an unnecessary acceleration component is detected.

  In addition, the vehicle 10 includes, for example, a portion that has elasticity and functions as a spring like the tire portions of the wheels 12L and 12R, and unavoidable backlash is included in the connection portion of each member. For this reason, the lateral acceleration sensor is considered to be attached to the vehicle body through inevitable play and springs, and therefore acceleration caused by displacement of the play and springs is also detected as an unnecessary acceleration component.

  Such an unnecessary acceleration component may deteriorate the controllability of the vehicle body tilt control system. For example, if the control gain of the vehicle body tilt control system is increased, control system vibration, divergence, and the like due to unnecessary acceleration components occur, so that it is not possible to increase the control gain even if responsiveness is to be improved. .

  Therefore, in the present embodiment, a plurality of lateral acceleration sensors are arranged at different heights. In the example shown in FIGS. 1 and 3, there are two lateral acceleration sensors, a first lateral acceleration sensor 44a and a second lateral acceleration sensor 44b, and the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b are the same. They are arranged at different height positions. By appropriately selecting the positions of the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b, unnecessary acceleration components can be effectively removed. Similarly, the longitudinal acceleration sensor is also a first longitudinal acceleration sensor 44c and a second longitudinal acceleration sensor 44d, and the first longitudinal acceleration sensor 44c and the second longitudinal acceleration sensor 44d are arranged at different height positions. It is installed.

  Incidentally, the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b are general acceleration sensors. If the acceleration sensor has two or more axes, it can detect accelerations in a plurality of directions, for example, lateral and longitudinal accelerations of the vehicle body. That is, the functions of the lateral acceleration sensor and the longitudinal acceleration sensor can be exhibited.

  Therefore, in the present embodiment, the first lateral acceleration sensor 44a functions as the first longitudinal acceleration sensor 44c, and the second lateral acceleration sensor 44b functions as the second longitudinal acceleration sensor 44d. That is, the description will be made assuming that the first lateral acceleration sensor 44a and the first longitudinal acceleration sensor 44c are integrally configured, and the second lateral acceleration sensor 44b and the second longitudinal acceleration sensor 44d are integrally configured. The first lateral acceleration sensor 44a and the first longitudinal acceleration sensor 44c may be configured separately, and the second lateral acceleration sensor 44b and the second longitudinal acceleration sensor 44d may be configured separately.

Specifically, as shown in FIG. 3A, the first lateral acceleration sensor 44a and the first longitudinal acceleration sensor 44c are configured such that the distance from the road surface 18, that is, the height is L on the back surface of the riding section 11. ₁ is arranged. Further, the second lateral acceleration sensor 44b and the second longitudinal acceleration sensor 44d are disposed at a distance from the road surface 18, that is, a height of L ₂ on the back surface of the riding section 11 or the upper surface of the main body section 20. Yes. Note that L ₁ > L ₂ .

When turning, when the vehicle is turned with the vehicle body tilted inward (right side in the drawing) as shown in FIG. 3B, the first lateral acceleration sensor 44a detects the lateral acceleration. The detection value a ₁ is output, and the second lateral acceleration sensor 44b detects the lateral acceleration and outputs the detection value a ₂ . Although the center of the tilting motion when the vehicle body tilts, that is, the roll center, is strictly located slightly below the road surface 18, it is considered that the center is substantially equal to the road surface 18 in practice.

It is desirable that the first lateral acceleration sensor 44a, the first longitudinal acceleration sensor 44c, the second lateral acceleration sensor 44b, and the second longitudinal acceleration sensor 44d are both attached to a sufficiently rigid member. In addition, if the difference between L ₁ and L ₂ is small, the difference between the detection values a ₁ and a ₂ is small. Furthermore, it is preferable that the first lateral acceleration sensor 44a and the first longitudinal acceleration sensor 44c, the second lateral acceleration sensor 44b and the second longitudinal acceleration sensor 44d are both disposed above the link mechanism 30. Further, when the vehicle body is supported by a spring such as a suspension, the first lateral acceleration sensor 44a, the first longitudinal acceleration sensor 44c, the second lateral acceleration sensor 44b, and the second longitudinal acceleration sensor 44d are both so-called “springs”. It is desirable to be arranged “on”. Further, the first lateral acceleration sensor 44a, the first longitudinal acceleration sensor 44c, the second lateral acceleration sensor 44b, and the second longitudinal acceleration sensor 44d are both the axle of the wheel 12F that is the front wheel and the wheels 12L and 12R that are the rear wheels. It is desirable to be disposed between the two axles. Further, it is desirable that the first lateral acceleration sensor 44a, the first longitudinal acceleration sensor 44c, the second lateral acceleration sensor 44b, and the second longitudinal acceleration sensor 44d are both as close to the occupant as possible. Further, the first lateral acceleration sensor 44a, the first longitudinal acceleration sensor 44c, the second lateral acceleration sensor 44b, and the second longitudinal acceleration sensor 44d are both on the central axis of the vehicle body extending in the traveling direction when viewed from above. It is desirable to be located, i.e. not offset with respect to the direction of travel.

  In the present embodiment, a yaw rate sensor 44e is provided as a yaw angular velocity detecting means for detecting the angular velocity of the turning motion of the vehicle body, that is, the yaw angular velocity of the vehicle body. Specifically, the yaw rate sensor 44e is disposed between the seat 11a and the footrest 11b, for example.

  The yaw rate sensor 44e is a general yaw rate sensor, and for example, a gyro sensor is attached so as to detect a rotational angular velocity in a plane parallel to the road surface 18.

  The vehicle 10 in the present embodiment has a vehicle body tilt control system as a part of the control device. The vehicle body tilt control system is a kind of computer system and includes a tilt control device including an ECU (Electronic Control Unit) or the like. The tilt control device includes arithmetic means such as a processor, storage means such as a magnetic disk and a semiconductor memory, input / output interfaces, and the like, and includes a first lateral acceleration sensor 44a, a second lateral acceleration sensor 44b, a first longitudinal acceleration sensor 44c, The second longitudinal acceleration sensor 44d, the yaw rate sensor 44e, the vehicle speed sensor 54, the link motor 25, and the link brake 26 are connected. The tilt control device outputs a torque command value for operating the link motor 25 and a command for operating the link brake 26.

  The tilt control device performs feedback control during cornering so that the tilt angle of the vehicle body becomes zero in the lateral acceleration value detected by the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b. The link motor 25 is actuated so as to have an angle. That is, the tilt angle of the vehicle body is controlled so that the centrifugal force to the outside of the turn and gravity are balanced and the lateral acceleration component becomes zero. As a result, a force in a direction parallel to the longitudinal axis of the vehicle body acts on the vehicle body and the occupant on the riding section 11. Therefore, the stability of the vehicle body can be maintained and the turning performance can be improved.

  Further, as shown in FIG. 5, when it is determined that the position of the center of gravity M of the vehicle 10 is out of a predetermined controllable range, that is, a stable range in the horizontal plane, the operation of tilting the vehicle body is stopped. Control to do. The center of gravity M is the total center of gravity including not only the vehicle 10 but also the occupant on board and the loaded object.

  The predetermined range is a range in which an extension is defined by a line segment connecting the contact points of the wheels 12, and is a polygon formed by a line segment connecting the contact points of the wheels 12. The polygon is a quadrangle when the vehicle 10 is a four-wheel vehicle, and a triangle when the vehicle 10 is a tricycle. In the present embodiment, as shown in FIG. 5A, the polygon has apexes at the grounding point of the wheel 12F as the front wheel and the grounding points of the left and right wheels 12L and 12R as the rear wheels. An isosceles triangle K. When the position of the center of gravity M is outside the isosceles triangle K, the link brake 26 is operated to fix the rotation shaft of the link motor 25 so as not to rotate with respect to the body. Fix it so that it cannot bend or stretch.

In FIG. 5B, h is the height of the center of gravity M, that is, the distance from the road surface 18 to the center of gravity M. L is a horizontal component of the distance from the ground contact point of the wheel 12F to the center of gravity M. W is a distance between the treads, that is, the ground contact points of the left and right wheels 12L and 12R which are rear wheels. Further, a _Cx is a longitudinal acceleration acting on the center of gravity M, a _Cy is a lateral acceleration acting on the center of gravity M, and a _R is a tolerable lateral acceleration, that is, a marginal value of the lateral acceleration.

Here, the marginal value a _R of the lateral acceleration is expressed by the following equation (1).
a _R = W (l−ha _Cx ) / 2 hL _H (1)
When the following expression (2) is satisfied, the link brake 26 is operated to fix the link mechanism 30 so that it cannot bend and stretch.
a _R <| a _Cy | (2)
Thereby, even when subjected to disturbance, it is possible to effectively prevent the running state from becoming more unstable, and to maintain the stability of the vehicle body. In addition, the rider does not feel discomfort and the ride comfort is improved.

  Next, the configuration of the vehicle body tilt control system will be described.

  FIG. 6 is a block diagram showing the configuration of the vehicle body tilt control system in the embodiment of the present invention.

  In the figure, 46 is a tilt control ECU as a tilt control device, and includes a first lateral acceleration sensor 44a, a second lateral acceleration sensor 44b, a first longitudinal acceleration sensor 44c, a second longitudinal acceleration sensor 44d, a yaw rate sensor 44e, and a vehicle speed sensor. 54, connected to the link motor 25 and the link brake 26. The tilt control ECU 46 includes an acceleration calculation unit 48, a tilt control unit 47, and a link motor control unit 42.

Here, the acceleration calculation unit 48 calculates a combined lateral acceleration based on the lateral acceleration detected by the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b. Further, the acceleration calculation unit 48 determines the center of gravity M based on the lateral acceleration and the longitudinal acceleration detected by the first lateral acceleration sensor 44a, the second lateral acceleration sensor 44b, the first longitudinal acceleration sensor 44c, and the second longitudinal acceleration sensor 44d. The longitudinal acceleration a _Cx and the lateral acceleration a _Cy acting on and the tolerable lateral acceleration a _R are calculated, and if the equation (2) is satisfied, a link stop command is output.

  The tilt control unit 47 calculates and outputs a speed command value as a control value based on the combined lateral acceleration calculated by the acceleration calculation unit 48 and the link stop command. The link motor control unit 42 outputs a torque command value as a control value for operating the link motor 25 based on the speed command value output from the inclination control unit 47, and the acceleration calculation unit 48 outputs the torque command value. Based on the link stop command, an operation command for the link brake 26 and an operation stop command for the link motor 25 are output.

  Next, the operation of the vehicle 10 configured as described above will be described. First, the operation of the lateral acceleration calculation process, which is a part of the operation of the vehicle body tilt control process in turning, is described.

  FIG. 7 is a diagram showing a dynamic model for explaining the leaning operation of the vehicle body during cornering in the embodiment of the present invention, and FIG. 8 is a flowchart showing the operation of the lateral acceleration calculation process in the embodiment of the present invention.

  When turning is started, the vehicle body tilt control system starts the vehicle body tilt control process. By performing posture control, the vehicle 10 turns with the link mechanism 30 in a state where the vehicle body is tilted inward (right side in the drawing) as shown in FIG. Further, during turning, a centrifugal force to the outside of the turning acts on the vehicle body, and a lateral component of gravity is generated by tilting the vehicle body to the inside of the turn. Then, the acceleration calculation unit 48 executes a lateral acceleration calculation process, calculates a combined lateral acceleration a, and outputs it to the tilt control unit 47. Then, the inclination control unit 47 performs feedback control, and outputs a speed command value as a control value such that the value of the combined lateral acceleration a becomes zero. Then, the link motor control unit 42 outputs a torque command value to the link motor 25 based on the speed command value output from the inclination control unit 47.

The vehicle body tilt control process is a process that is repeatedly executed by the vehicle body tilt control system at a predetermined control cycle T _S (for example, 5 [ms]) while the vehicle 10 is turned on. This is a process for improving turning performance and ensuring passenger comfort.

  In FIG. 7, 44A is a first sensor position indicating the position where the first lateral acceleration sensor 44a is disposed on the vehicle body, and 44B is a first position indicating the position where the second lateral acceleration sensor 44b is disposed on the vehicle body. Two sensor positions.

The acceleration detected by the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b and outputting the detected value is <1> centrifugal force acting on the vehicle body when turning, and <2> tilting the vehicle body toward the inside of the turn. The lateral component of the generated gravity, <3> the first lateral acceleration sensor 44a and the like due to the inclination of the vehicle body, the backlash or the displacement of the spring, etc., when only one of the left and right wheels 12L and 12R falls into the depression of the road surface 18; The acceleration generated by the displacement of the second lateral acceleration sensor 44b in the circumferential direction, and the <4> operation of the link motor 25 or the reaction thereof causes the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b to be displaced in the circumferential direction. It is considered that there are four accelerations caused by this. Of these four acceleration, the <1> and <2>, the height of the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b, that is, independent of L ₁ and L _2. On the other hand, since <3> and <4> are accelerations generated by displacement in the circumferential direction, they are proportional to the distance from the roll center, that is, roughly proportional to L ₁ and L ₂ .

Here, the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44a and the second lateral acceleration sensor 44b detect and output the detected value. The acceleration <3> is defined as a _X1 and a _X2, and the first lateral acceleration sensor 44a and the second lateral acceleration. The acceleration of <4>, which is detected by the sensor 44b and outputs the detected value, is a _M1 and a _M2 . Further, the acceleration of <1> to the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b outputs the detected value detected by the a _T, a first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b is detected Then, the acceleration of <2> that outputs the detected value is defined as a _G. Since <1> and <2> are irrelevant to the heights of the first and second lateral acceleration sensors 44a and 44b, the detection values of the first and second lateral acceleration sensors 44a and 44b are equal. .

Then, only one of the left and right wheels 12L and 12R are inclined in the vehicle body due to the fall in a recess of a road surface 18, the angular velocity omega _R the circumferential direction of displacement by the displacement or the like of Gataya spring, the angular acceleration omega _{Let R} '. Further, the angular velocity of the circumferential displacement due to the operation of the link motor 25 or its reaction is ω _M , and the angular acceleration is ω _M ′. The angular velocity ω _M or the angular acceleration ω _M ′ can be obtained from the detection value of the link angle sensor.

Then, a _X1 = L ₁ ω _R ′, a _X2 = L ₂ ω _R ′, a _M1 = L ₁ ω _M ′, a _M2 = L ₂ ω _M ′.

Further, when the detection value of the acceleration by the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b is detecting and outputting the a ₁ and a _2, a ₁ and a _2, four acceleration <1> to <4 It is represented by the following formulas (3) and (4).
_{a 1 = a T + a G} + L 1 ω R '+ L 1 ω M' ··· (3)
_{a 2 = a T + a G} + L 2 ω R '+ L 2 ω M' ··· formula (4)
Then, when the equation (4) is subtracted from the equation (3), the following equation (5) can be obtained.
a ₁ -a ₂ = (L ₁ -L ₂ ) ω _R '+ (L ₁ -L ₂ ) ω _M ' (5)
Here, the values of L ₁ and L ₂ are known because they are the heights of the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b. The value of ω _M ′ is known because it is a differential value of the angular velocity ω _M of the link motor 25. Then, on the right side of the equation (5), only the value of ω _R ′ of the first term is unknown, and all other values are known. Therefore, the value of ω _R ′ can be obtained from the detection values a ₁ and a _{2 of} the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b. That is, unnecessary acceleration components can be removed based on the detection values a ₁ and a ₂ of the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b.

When the vehicle body tilt control system starts the vehicle body tilt control process, the acceleration calculation unit 48 starts the lateral acceleration calculation process, and first acquires the first lateral acceleration sensor value a ₁ (step S1) and the second lateral acceleration. A sensor value a ₂ is acquired (step S2). Then, the acceleration calculation unit 48 calculates the acceleration difference Δa (step S3). The Δa is expressed by the following equation (6).
Δa = a ₁ −a ₂ Formula (6)
Subsequently, the acceleration calculation unit 48 performs ΔL call (step S4), and performs the L ₂ call (step S5). The ΔL is expressed by the following equation (7).
ΔL = L ₁ −L ₂ Formula (7)
Subsequently, the acceleration calculation unit 48 calculates the combined lateral acceleration a (step S6). The combined lateral acceleration a is a value corresponding to the lateral acceleration sensor value a in the case where there is one lateral acceleration sensor, and the first lateral acceleration sensor value a ₁ and the second lateral acceleration sensor value a ₂ are calculated. It is a synthesized value and is obtained by the following equations (8) and (9).
a = a ₂ − (L ₂ / ΔL) Δa (8)
a = a ₁ − (L ₁ / ΔL) Δa (9)
Theoretically, the same value can be obtained by both formula (8) and formula (9), but the acceleration caused by the circumferential displacement is proportional to the distance from the roll center, so in practice, the roll center. It is desirable to use a ₂ which is a detection value of the lateral acceleration sensor closer to the second lateral acceleration sensor 44b as a reference. Therefore, in the present embodiment, the combined lateral acceleration a is calculated by equation (8).

  Finally, the acceleration calculation unit 48 sends the combined lateral acceleration a to the tilt control unit 47 (step S7) and ends the process.

Thus, in this embodiment, a first lateral acceleration sensor 44a and a second lateral acceleration sensor 44b is placed in different height positions, a first lateral acceleration sensor value a ₁ and the second lateral acceleration sensor A combined lateral acceleration a obtained by combining the value a ₂ is calculated, and feedback control is performed so that the value of the combined lateral acceleration a becomes zero to control the tilt angle of the vehicle body.

  As a result, unnecessary acceleration components can be removed, so that it is not affected by road surface conditions, the occurrence of vibrations and divergence of the control system can be prevented, and the control gain of the vehicle body tilt control system is increased. Control responsiveness can be improved.

  In this embodiment, the case where there are two lateral acceleration sensors has been described. However, if there are a plurality of lateral acceleration sensors arranged at different heights, the number of lateral acceleration sensors is three or more. It can be any number.

  Next, the operation of the inclination control process for outputting the speed command value to the link motor control unit 42 will be described.

  FIG. 9 is a flowchart showing the operation of the vehicle tilt control process according to the embodiment of the present invention.

  In the tilt control process, the tilt control unit 47 first receives the combined lateral acceleration a from the acceleration calculation unit 48 (step S11).

Subsequently, the inclination control unit 47 makes an _old call (step S12). a _old is the combined lateral acceleration a stored when the vehicle body tilt control process is executed last time. In the initial setting, a _old = 0.

Subsequently, the inclination control unit 47 acquires a control cycle T _S (step S13), and calculates a differential value of a (step S14). Here, when the differential value of a is da / dt, the da / dt is calculated by the following equation (10).
da / dt = (a−a _old ) / T _S (10)
And the inclination control part 47 preserve _| saves as _aold = a (step S15). That is, the lateral acceleration sensor value a acquired at the time of execution of the current vehicle body tilt control process is stored as a _old in the storage unit.

Then, tilt control unit 47 calculates the first control value U _P (step S16). Here, if the control gain of the proportional control operation, that is, the proportional gain is C _P , the first control value _UP is calculated by the following equation (11).
U _P = C _P a ··· formula (11)
Then, tilt control unit 47 calculates the second control value U _D (step S17). Here, the control gain of the differential control operation, i.e., when the derivative time and C _D, the second control value U _D is calculated by the following equation (12).
U _D = C _D da / dt (12)
Subsequently, the inclination control unit 47 calculates a third control value U (step S18). Third control value U is the sum of the first control value U _P and the second control value U _D, is calculated by the following equation (13).
U = U _P + U _D ··· formula (13)
Finally, the inclination control unit 47 outputs the third control value U as a speed command value to the link motor control unit 42 (step S19), and ends the process.

  Next, the operation of the link motor control process for outputting a torque command value to the link motor 25 will be described.

  FIG. 10 is a flowchart showing the operation of the link motor control process in the embodiment of the present invention.

  In the link motor control process, the link motor control unit 42 first receives the third control value U from the inclination control unit 47 (step S21).

  Subsequently, the link motor control unit 42 calculates an angular velocity Δη of the link angle of the link mechanism 30 based on the link angle sensor value η detected by the link angle sensor (step S22).

  Further, the link motor control unit 42 may omit the operation of step S22 when the value of Δη can be acquired from the acceleration calculation unit 48 or the like.

Subsequently, the link motor control unit 42 calculates a control error (step S23). Here, when the control error is ε, ε is calculated by the following equation (14).
ε = U−Δη Formula (14)
U is the third control value U received from the inclination control unit 47.

Subsequently, the link motor control unit 42 obtains the motor control proportional gain G _MP (step S24). The value of the motor control proportional gain _{GMP is} a value set based on experiments or the like, and is stored in advance in the storage means.

Subsequently, the link motor control unit 42 calculates a torque command value for operating the link motor 25 (step S25). Here, when the torque command value is U _T , the U _T is calculated by the following equation (15).
U _T = G _MP ε (15)
Finally, the link motor control unit 42 outputs the torque command value _UT to the link motor 25 (step S26) and ends the process.

  Next, the operation of the link brake control process for outputting the operation command for the link brake 26 and the operation stop command for the link motor 25 will be described.

  FIG. 11 is a flowchart showing the operation of the link brake control process in the embodiment of the present invention.

In the link brake control process, the acceleration calculation unit 48 first calculates the longitudinal acceleration at the center of gravity, that is, the longitudinal acceleration a _Cx acting on the center of gravity M (step S31). Here, when the detected longitudinal acceleration values detected by the first longitudinal acceleration sensor 44c and the second longitudinal acceleration sensor 44d are a _x1 and a _x2 , the a _Cx is calculated by the following equation (16). The a _x1 and a _x2 are values with the traveling direction being positive.
a _Cx = h (a _x1 −a _x2 ) / (L ₁ −L ₂ ) + a _x2 −L ₂ (a _x1 −a _x2 ) / (L ₁ −L ₂ ) (16)
Subsequently, the acceleration calculation unit 48 calculates a marginal value a _R for the lateral acceleration (step S32). The a _R is calculated by the equation (1).

Subsequently, the acceleration calculation unit 48 calculates the lateral acceleration at the center of gravity, that is, the lateral acceleration a _Cy acting on the center of gravity M (step S33). Here, if the detected values of the lateral acceleration detected by the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b are a _y1 and a _y2 , the a _Cy is calculated by the following equation (17).
_{a Cy = h (a y1 -a} y2) / (L 1 -L 2) + a y2 -L 2 (a y1 -a y2) / (L 1 -L 2) ··· (17)
Subsequently, acceleration calculator 48 compares the absolute value of the value and a _Cy of the calculated a _R, the value of a _R is equal to or less than the absolute value of a _Cy (step S34 ). If the value of a _R is less than the absolute value of a _Cy , the acceleration calculation unit 48 outputs a link stop command to the tilt control unit 47 (step S35), and the process ends. Then, the link stop command is transmitted from the inclination control unit 47 to the link motor control unit 42 as it is. The link motor control unit 42 outputs an operation command for the link brake 26 and an operation stop command for the link motor 25 based on the link stop command. As a result, the link motor 25 stops operating and the link brake 26 operates to fix the rotation shaft of the link motor 25 so as not to rotate with respect to the body, so that the link mechanism 30 is fixed so as not to bend and stretch.

Note that the value of a _R, it is determined whether or not less than the absolute value of a _Cy, when the value of a _R is not less than the absolute value of a _Cy, acceleration calculating unit 48, tilt control link operation permission command It outputs to the part 47 (step S36), and complete | finishes a process. Then, the link operation permission command is transmitted from the inclination control unit 47 to the link motor control unit 42 as it is. The link motor control unit 42 outputs a release command for the link brake 26 and an operation permission command for the link motor 25 based on the link operation permission command. As a result, the link motor 25 is operated, and the link brake 26 is released so that the rotation shaft of the link motor 25 is released from the non-rotatably fixed state with respect to the body, so that the link mechanism 30 can bend and stretch. Is done.

  Thus, in the present embodiment, based on the lateral acceleration detected by the first lateral acceleration sensor 44a and the second lateral acceleration sensor 44b and the longitudinal acceleration detected by the first longitudinal acceleration sensor 44c and the second longitudinal acceleration sensor 44d. Thus, it is determined whether or not the position of the center of gravity M is out of the controllable range. If the position of the center of gravity M is out of the controllable range, the operation of tilting the vehicle body is stopped.

  As a result, when the running state becomes unstable due to factors such as a sudden change in the shape of the road surface 18, it is possible to effectively prevent the running state from becoming further unstable. A high vehicle 10 can be provided.

  Further, when the position of the center of gravity M in the horizontal plane is located outside the isosceles triangle K formed by a line segment connecting the grounding points of the wheels 12, it is determined that the center of gravity M is out of the controllable range. It is possible to appropriately determine that the state has become unstable.

  Furthermore, since the link brake 26 is operated and the rotation shaft of the link motor 25 is fixed to the body so as not to rotate, the link mechanism 30 can be fixed securely.

  In addition, this invention is not limited to the said embodiment, It can change variously based on the meaning of this invention, and does not exclude them from the scope of the present invention.

  The present invention can be used for a vehicle having at least a pair of left and right wheels.

DESCRIPTION OF SYMBOLS 10 Vehicle 11 Boarding part 12F, 12L, 12R Wheel 20 Main-body part 25 Link motor 26 Link brake 30 Link mechanism 44a 1st lateral acceleration sensor 44b 2nd lateral acceleration sensor 44c 1st longitudinal acceleration sensor 44d 2nd longitudinal acceleration sensor

Claims (4)

A vehicle body including a steering unit and a drive unit coupled to each other;
A wheel rotatably attached to the steering unit, the steering wheel for steering the vehicle body;
A wheel rotatably attached to the drive unit, the drive wheel driving the vehicle body;
A plurality of sensors for detecting lateral acceleration and longitudinal acceleration acting on the vehicle body;
A link mechanism for tilting the steering part or the drive part in the turning direction;
An inclination actuator device for operating the link mechanism;
A control device for controlling the tilt of the vehicle body by controlling the actuator device for tilting,
The control device performs tilt control based on the lateral acceleration detected by the plurality of sensors, and determines whether the position of the center of gravity is out of a controllable range based on the lateral acceleration and the longitudinal acceleration detected by the plurality of sensors. A vehicle characterized in that the operation of tilting the vehicle body is stopped when the position of the center of gravity is outside the controllable range.   The control device determines that the position of the center of gravity is out of a controllable range when the position of the center of gravity in a horizontal plane is located outside a polygon formed by a line segment connecting the grounding points of the wheels. The vehicle described. A link brake for fixing the link mechanism;
3. The control device according to claim 1, wherein when the position of the center of gravity is out of a controllable range, the control device operates the link brake to fix the link mechanism and stops the operation of the tilt actuator device. The vehicle described.   The vehicle according to claim 3, wherein the tilt actuator device is a motor, and the link brake is a brake that fixes a rotation shaft of the motor to a body of the motor.

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