JPH0971288A - Manual device with drive auxiliary means and its control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control a manual device driven by definite torque in proportion to man power by supplementing torque by a drive auxiliary means in response to both torque applied to a drive shaft by man power and target synthesized torque to be applied to the drive shaft. SOLUTION: A comparison operation circuit 44 computes torque to be manually applied to a crank shaft. Concurrently target synthesized torque for footing force is computed out of a memory. Auxiliary torque by an electric motor is computed based on the difference in torque so as to be stored in the memory, and concurrently a current value required for the electric motor to apply auxiliary torque to the crank shaft, is computed so as to be transmitted to a drive control circuit 46. By this constitution, torque is applied to the crank shaft by the electric motor 3O, and the sum of auxiliary torque and torque thereby coincides with the target synthesized torque.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a bicycle, a three-wheeled vehicle,
The present invention relates to a human power device in which a drive assisting means such as an electric motor is attached to a device driven by human power such as a wheelchair or a rowing boat, and a control method thereof, and particularly to a human power device for smoothing a load required for a user and its control Regarding the method.

[0002]

2. Description of the Related Art Conventionally, there is known a device which is provided with a drive assisting means such as an electric motor in a device driven by human power to reduce a load on a user. For example, in Japanese Unexamined Patent Publication No. 4-244496, an electric motor is connected to a drive system of a bicycle.
As shown in, the torque T _cp (step 1) applied to the drive shaft (11) by depressing the pedal and the rotational speed N of the pedal are
Disclosed is a method of detecting _c (step 2) and applying a control voltage proportional to the product of these values (step 3) to the electric motor (steps 4 and 5) to assist the driving by the user. .

[0003]

The rotational torque T applied to the drive shaft via the pedal of the bicycle is as shown in FIG.
It is represented by the product (F × L ′) of the vertical force F by which the user steps on the pedal and the horizontal distance L ′ from the center of rotation of the crank arm base end to which the pedal is attached to the pedal. Here, if the horizontal distance L ′ between the pedal and the rotation center is the crank length L (constant value) and the rotation angle of the left pedal (pedal shown in FIG. 9) from the vertical direction is θ, then L ′ = L × It is indicated by sin θ. When the rotation angle of the left pedal is 0 ° ≦ θ <180 °, the human power F acts only on the left pedal, and the human power does not act on the right pedal (not shown). Further, when the rotation angle of the left pedal is 180 ° ≦ θ <360 °, the human power F acts only on the right pedal. Therefore, the torque T applied to the drive system by the human power F is represented by the following equation and FIG. 10 when the user pedals the pedal at a constant pedaling force (F = constant) and at a constant rotation speed (N _c = constant).

[0004]

[Equation 1]

Auxiliary torque T applied to the drive system by the electric motor
_{When M} is proportional to the manpower torque T applied to the drive shaft (11) by the pedal, the auxiliary torque T _M is shown as the alternate long and short dash line in FIG. 10, and the combined torque (T
+ T _M ) is shown by the dotted line in FIG. As you can see from the figure,
The combined torque (T + T _M ) fluctuates greatly according to the rotation angle of the pedal. When the combined torque (T + T _M ) fluctuates greatly, the speed of the bicycle also increases or decreases, and the operability and riding comfort deteriorate. This problem is because conventionally, the required assist torque T _M is calculated with reference to the torque T of human power.

The manpower torque T is not proportional to the manpower F, and as is apparent from FIG. 9, the manpower torque T is zero or extremely small at the top dead center and the bottom dead center of the pedal even if the manpower F is large. Therefore, in order to obtain the required rotational force, the pedal must be strongly depressed at the top dead center of the pedal, which causes the user to be tired. The inventors of the present invention have conceived that, when the assist torque is generated based on the human power F on the pedal, the human power F can obtain a necessary rotational force with a substantially constant value.

An object of the present invention is to control the human power device to drive with a constant torque T _ref proportional to the human power F when the user applies the human power F to the human power device. Is not compensated by the drive assisting means, the load fluctuation that the user has to add to the human power device is eliminated, and the operability and the riding comfort are improved.

[0008]

In order to solve the above problems, in a human power device equipped with a drive assisting means of the present invention, a human power detecting means for detecting or calculating the magnitude of human power F.
(5) and the torque T applied to the drive shaft (11) by the human power F is detected, and the magnitude of the power to be output by the drive assisting means (3) is controlled according to the measured value of the human power detecting means (5). Control means
(4) and are provided. The control means (4) determines the target combined torque T _ref to be applied to the drive shaft (11) in accordance with the human power F,
The torque T _M according to the target torque T _ref and the torque T applied to the drive shaft (11) by the human power F is applied to the drive assisting means (3).
Controls the drive shaft (11).

Further, in the control method of the human power device having the drive assisting means of the present invention, the human power F applied to the driving means (2) is
Is detected or calculated, the torque T applied to the drive shaft (11) by the human power F is detected, the target combined torque T _ref applied to the drive shaft (11) is determined according to the human power F, and the drive shaft is calculated by the human power F.
The drive assisting means (3) controls the drive shaft (11) to apply a torque T _M corresponding to the human torque T applied to (11) and the target combined torque T _ref .

[0010] and the target combined torque T _ref, the relationship between the torque T according to human power F, a difference between the target combined torque T _ref and the torque T, the drive assist means (3) is a drive shaft (11) The applied torque T _M is T _ref −T.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described. In the following, an example in which the bicycle (6) is used as the human power device (1) and the electric motor (30) is used as the drive assisting means (3) will be described. However, the present invention provides a bicycle (6)
The present invention is not limited to the above, but can be applied to a device that uses human power as a drive source, such as a three-wheeled bicycle, a wheelchair, and a rowing boat. In the following description, "front" means the front wheel (62) side,
"Left" means the left side of the bicycle (6) when viewed from behind. As shown in FIG. 1, a bicycle (6) with an electric motor is provided with a handle (60) and a front wheel (62) at a front portion of a frame (61), and a saddle (63) is provided at a central upper portion of the frame (61). Is provided. Endless chain (64) tensioned sprockets (65) and (66) are respectively arranged at the lower center and rear of the frame (61), and the front sprocket (65) (hereinafter referred to as `` driving sprocket '') is A pedal (8) is mounted via a crankshaft (7) equipped with a human power detecting means (5) described later. Rear sprocket (66) has rear wheels (62a)
By rotating (8), the chain (64) runs and the rear wheels (62a) rotate.

The electric motor (30) is a DC drive type motor and is connected to the chain (64) through a speed reduction mechanism (32). A power supply mechanism (31) is connected to the electric motor (30), and the power supply mechanism (31) is connected to and controlled by the control means (4). Power supply mechanism (31), electric motor (30) and reduction mechanism (3
2) is placed on the frame (61) in the center of the bicycle (6).

As shown in FIGS. 2 and 3, the drive means (2) comprises the drive sprocket, the crankshaft (7) and the pedal (8). Crankshaft (7) is the frame
A drive shaft (11) rotatably supported by a bearing (75) provided in (61) and having a drive sprocket (65), and the drive shaft (1).
Crank arms (72) projecting perpendicularly to the drive shaft (11) from both ends of (1), and crank pins projecting parallel to the drive shaft (11) from the tip of each crank arm (72). (73) and. A pedal (8) is rotatably provided at the tip of the crank pin (73). As shown in FIGS. 2 and 3,
The distance between the axes of the drive shaft (11) and the crank pin (73) is L.

A human power detecting means (5) is provided inside the drive shaft (11) and a pedal (8) described later. An oil hole (9) communicating with the inside of the crank arm (72) and the inside of the crank pin (73) is formed inside the drive shaft (11) on the left side of the center thereof. A hole (90) for communicating the oil hole (9) with an oil reservoir (91) described later is formed through the end of the oil hole (9) on the side of the drive shaft (11). The oil sump (91) is filled with oil (94). A taper pin (93) is slidably provided at the end of the oil hole (9) on the crank pin (73) side to close the oil hole (9). The taper pin (93) has a taper formed at the tip,
The other end is fitted into the oil hole (9) while being slidable in the oil hole (9) and keeping the oil hole (9) liquid-tight. The taper pin (93) is biased in the direction opposite to the crank pin (73) by a spring (87) provided on the pedal (8).

A gear (74) is cut on the outer periphery near the left end of the drive shaft (11), and a known rotary type for detecting the rotation angle θ of the crankshaft (7) on the gear (74). Potentiometer
The gear (52b) provided on the shaft (52a) of (52) is meshed.
The potentiometer (52) is electrically connected to an electric circuit (42) described later. The rotation angle θ of the crankshaft (7)
Is the angle between the plane passing through the drive shaft (11) and the crank arm (72) as shown in FIG.
When the planes are parallel to each other and the left crank arm (72) is located above, the degree is 0 degree.

The oil sump (91) is a cylinder provided around the drive shaft (11), and is filled with oil (94) inside,
Bearings with oil seals at both ends of the cylinder (9
The drive shaft (11) is rotatably supported by 1a). A detection hole (92) having a diameter smaller than the diameter of the oil hole (9) inside the crankshaft (7) is formed through the side surface of the cylindrical body, and the detection hole (92) has a potentiometer ( 53) is slidably provided. Potentiometer for detecting pedal force (53)
Is a known direct-acting potentiometer (53), which is electrically connected to an electric circuit (42) described later, and the shaft (53a) of the potentiometer (53) changes the oil pressure in the oil sump (91). Sliding in the detection hole (92) in proportion. The reason why the potentiometer (53) for detecting the pedaling force is not directly arranged on the crankshaft (7) is that the crankshaft (7) rotates, so that the wiring becomes complicated when it is attached to the crankshaft (7). The detection hole (92) has a smaller diameter than the oil hole (9) inside the crankshaft (7) because the phase amount due to the sliding of the taper pin (93) is detected in the detection hole (92).
This is for sensitive and accurate detection.

A pedal (8) is rotatably provided at the tip of the crank pin (73) as shown in FIGS. 2 and 3. The pedal (8) has a tread plate (81) to which a user's treading force is applied. The tread (81) has grooves (8) formed in the left and right side plates (84).
4a) is slidable in the vertical direction, and a taper receiving groove (83) with a semicircular cross section is provided at the approximate center of the end of the footboard (81) inside the housing. The plate (82) is provided, and the tapered pin (93) slidably provided on the tip of the crankshaft (7) slides. Also, the left side plate (84)
A plate piece (85) is projected on the inner side of the plate piece (85).
Springs that push the treads (81) outwards
(86) has been deployed. Furthermore, a spring (87) is arranged between the left end of the plate piece (85) and the tapered tip of the tapered pin (93),
The taper pin (93) is urged in the direction opposite to the crank pin (73), that is, in the direction of the plate piece (85).

The potentiometers (52) and (53) of the human power detection means (5) having the above-mentioned structure are controlled by the electric circuit (42) which is the control means (4). As shown in FIG. 4, the electric circuit (42) is
It is mainly composed of a central processing circuit (CPU (43)), and the CPU (43) has a comparison processing circuit (44), detected human power F, and data such as a target combined torque T _ref corresponding thereto. The memory (45) in which is stored is connected to the drive control circuit (46) that controls the power supply mechanism (31). The pedaling force detection potentiometer (53) and the crank angle detection potentiometer (52) are connected to the comparison operation circuit (44) via an amplification circuit and an A / D conversion circuit (not shown). The memory (45) has a function of storing auxiliary torque data described later in addition to the above data.

The operation of the electric motor-operated bicycle (6) having the above structure will be described with reference to the flowchart of FIG. still,
In the following control, the left pedal (8) is forward, that is, 0 ° ≤
When θ <180 ° (hereinafter “first half cycle”), the human power F is measured, and when 180 ° ≦ θ <360 ° (hereinafter “second half cycle”), the same human power as the immediately preceding first half cycle is measured. Assuming that F is added, the torque assistance by the electric motor (30) in the second half cycle is the same as the torque assistance in the first half cycle. When the user puts his / her foot on the pedal (8) and pedals the pedal (8), the pedal force of the user is applied to the tread plate (81). The rotation angle θ of the crank arm (72) at this time is measured by the potentiometer (52) for crank angle detection (step 1). As described above, in the bicycle (6), the force of the user is applied only to the pedal (8) located in front. The rotation angle θ is measured as a resistance value by the crank angle detecting potentiometer (52) and sent to the electric circuit (42). If the measured crank angle θ is in the first half cycle, the pedal (8)
Measure the pedaling force applied to (step 2). The case where the measured crank angle θ is in the second half period will be described later.

When the crank angle is in the first half cycle, the pedaling force F applied to the pedal (8) is measured in parallel with the above operation.
(Step 3). When the user depresses the pedal (8),
The step plate (81) is pushed down against the resistance of the spring (86), and the taper pin (93) retracts inside the oil hole (9) along the taper receiving groove (83) of the taper plate (82). By the movement of the taper pin (93), a part of the oil (94) in the oil hole (9) flows out to the oil sump (91) and pushes up the shaft (53a) of the potentiometer (53) for detecting the pedaling force. The movement of the shaft (53a) of the pedal force detecting potentiometer (53) is sent to the electric circuit (42) as a resistance value. The measured values of the pedaling force detection potentiometer (53) and the crank angle detection potentiometer (52) are input to the comparison calculation circuit (44) as resistance values. After these resistance values are amplified and A / D converted,
It is input to the comparison operation circuit (44).

In the comparison operation circuit (44), the pedaling force F and the crank rotation angle θ are obtained from these resistance values, and the torque T = Fsinθ × L that the human force F applies to the crankshaft (7) is calculated.
The pedaling force F of the left pedal (8) is shown in FIG. 7, and the torque T is shown by the solid line in FIG. At the same time, the target combined torque T _ref (dotted line in FIG. 8) for the pedal effort F is derived from the memory (45).
(Step 4). Next, the difference from the torque T (T _ref −T, FIG.
A) to auxiliary torque T _M = T _ref from the electric motor (30)
-T is calculated (step 5, dashed-dotted line in FIG. 8) and stored in the memory (45) as auxiliary torque data (step 6), and the auxiliary torque T _M is supplied to the crankshaft (7) by the electric motor (30).
A current value I = T _M / K (K: torque constant) required to supply the current is calculated and transmitted to the drive control circuit (46) (step 7). The drive control circuit (46) issues a command to flow a current value I ′ = I ₀ + I obtained by adding the transmitted current value I to the current value I ₀ being fed by the power feeding mechanism (31) at that time. Send to 31). The torque T is applied to the crankshaft (7) by the electric motor (30).
_{When M} is added (step 8), the sum of the auxiliary torque T _M and the torque T matches the target combined torque T _ref . Therefore,
The electric motorized bicycle (6) runs with torque T _ref .

When the crank angle is in the second half cycle, the electric motor (30) continuously applies the auxiliary torque T _M in the first half cycle. That is, using the auxiliary torque data stored in the memory (45) in step 6 above, the same current value I ′ as in the first half cycle is used.
The electric motor (30) is driven by (step 7).

The above operation is repeated while the user pedals the bicycle (6). As a result, the bicycle (6) is driven by the torque determined based on the pedal effort of the user. If the torque generated by the pedaling force is less than the target torque,
Driving of the crankshaft (7) is assisted by the electric motor (30).

FIG. 6 shows another embodiment of means for detecting the pedaling force of the pedal (8). Oil hole in the crankshaft (7)
A wire (95) is provided instead of the oil (94) in (9), one end of the wire is connected to the taper pin (93), and the other end is connected to the drive shaft (1
It is connected to one end of a lever (96) pivotally supported by a hole (90) opened in the wall surface of 1). The other end of the lever (96) is in contact with a disc (97) slidably arranged on the drive shaft (11), and the disc (97) has a shaft of a direct acting potentiometer (53).
The disc (97) is in contact with the disc (97) in a constantly biased state. When the pedaling force is applied to the pedal (8), the disc (97) is pushed and moved by the lever (96), and the potentiometer (53) is moved.
Push in the shaft (53a). Axis (53a) of potentiometer (53)
Similarly to the above, the movement amount of is transmitted to the electric circuit as a resistance value, and the pedaling force of the pedal (8) is calculated in the same manner as above.

The above description of the embodiments of the present invention is for explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope. Further, it goes without saying that the configuration of each part of the present invention is not limited to the above example, and various modifications can be made within the technical scope described in the claims.

For example, in the above embodiment, the means for detecting the pedal effort is provided on the left side of the crankshaft (7), but the human power detecting means (5) may be attached on the right side or both. It is also possible to mount a strain sensor or the like on the drive shaft (11), calculate the pedaling force from the means for detecting the crank angle and the detection value of the strain sensor, and perform the above control.

[0027]

According to the human power device (1) having the drive assisting means (3) and the control method thereof, the auxiliary torque T _M is generated based on the force F by which the user drives the human power device (1). It was generated, manpower device (1) by a torque T and assist torque _M by human power F can be made to drive at a constant torque T _{r ef.} The torque T generated by the user is the target torque T
_When it does not reach the _ref , the drive assisting means (3) assists the drive force to match the drive torque with the target torque T _ref . Therefore, the manpower device (1) is operated with a constant torque T
_{When the} vehicle is driven by _ref , the load that the user has to add does not fluctuate, fatigue of the user is reduced, and operability and riding comfort are improved.

[Brief description of drawings]

FIG. 1 is a side view of a bicycle with an electric motor.

FIG. 2 is a sectional view of a crankshaft.

FIG. 3 is a sectional view of a pedal.

FIG. 4 is a diagram showing an electric circuit.

FIG. 5 is a flowchart showing a flow of operations of the present invention.

FIG. 6 is a partial cross-sectional view of driving means.

FIG. 7 is a graph showing a pedaling force F.

FIG. 8 is a graph showing torques T, T _ref and T _M.

FIG. 9 is a side view of a drive shaft and a pedal.

FIG. 10 is a graph showing conventional torque T and auxiliary torque T _M.

FIG. 11 is a flowchart showing a flow of a conventional operation.

[Explanation of symbols]

 (1) Human power device (2) Drive means (3) Drive assist means (30) Electric motor (4) Control means (5) Human power detection means (42) Electric circuit (6) Bicycle with electric motor (7) Crankshaft ( 8) Pedal

Claims (4)

[Claims] 1. A human power drive means (2) for driving the drive shaft (11) by a human power connected to the drive shaft (11), and a drive shaft (1).
A human-powered device comprising a drive assisting means (3) which is linked to 1) and assists the drive of a drive shaft (11) by a human-powered driving means by power, and which detects or calculates the magnitude of the human power F. Detection means (5)
And a control means (4) for detecting the torque T by the human power F and controlling the magnitude of the power to be output by the drive assisting means (3) according to the measured value of the human power F by the human power detection means (5). The control means (4) determines a target combined torque T _ref to be applied to the drive shaft (11) in accordance with the human force F, and a torque T applied to the drive shaft (11) by the human force F and a target combined torque. T _ref
The drive assisting means (3) produces the torque T _M according to
A human-powered device having a drive assisting means characterized by performing control to be added to the power source. 2. A target combined torque T _ref, the relationship between the torque T according to human power F, a difference between the target combined torque T _ref and the torque T, the drive assist means (3) is a drive shaft (11) The device of claim 1, wherein the torque T _M applied to T _ref is T _ref −T. 3. A human-powered driving means (2) for driving the drive shaft (11) by human power connected to the drive shaft (11), and a drive shaft (1).
A method of controlling a drive assisting means (3) for assisting the drive of a drive shaft (11) by a human-powered driving means by a power in cooperation with 1), and a magnitude of a human power F applied to the driving means (2). Is calculated or calculated, the human torque T is detected, and the drive shaft (11) is detected according to the human power F.
The target combined torque T _ref to be applied to the drive shaft (11) is determined by the human power F and the target combined torque T
_The drive assisting means (3) applies the torque T _M according to _ref to the drive shaft (1
A method for controlling a human-powered device, characterized by performing control in addition to 1). 4. The relationship between the torque T applied to the drive shaft by a target combined torque T _ref and human power F (11), a difference between the target combined torque T _ref and the torque T, the drive assist means
The control method according to claim 3, wherein the torque T _M applied to the drive shaft (11) by (3) matches T _ref −T.