JPH1099380A - Wheelchair with auxiliary driving power - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the supply start of optimum auxiliary driving power when human power to either left or right driving wheel exceeds a prescribed dead zone width by outputting the auxiliary driving power to the other or both driving wheels. SOLUTION: The dead zone width is set based on the history of the human power added to left and right wheel hand rims in a dead zone width setting function 101. Also, a target current required by a motor 31 to generate target torque is obtained in a current limiter 106, a correction amount is obtained in a PID control circuit 107 based on the difference of a target value and a current detected in a current detection sensor 110, control signals are converted to the current in a bipolar power amplifier 109 and an auxiliary current is supplied to the motor 31. In this case, when the human power to either left or right driving wheel exceeds the prescribed dead zone width, the auxiliary driving power is outputted to the other or both driving wheels. Thus, the supply start of the optimum auxiliary driving power is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle in which forward and backward movements and turning operations are performed by a combined force of human power intermittently applied to left and right driving wheels and auxiliary power corresponding to the magnitude of the human power. Related to a wheelchair with auxiliary power.

[0002]

2. Description of the Related Art A wheelchair with auxiliary power has been proposed as an intermediate between a manual wheelchair and an electric wheelchair. This wheelchair with auxiliary power detects a human power intermittently applied to the left and right driving wheels, and applies an auxiliary power corresponding to the detected human power to the left and right driving wheels to make the wheelchair unable to walk. This reduces the physical burden on the user, allows the user to operate it as if a manual wheelchair, and alleviates mental distress.

[0003]

The wheelchair with the auxiliary power supplies the auxiliary power in accordance with the human power. However, in the case where the supply of the auxiliary power is started immediately when the human power is applied, There is a concern that a user may not always follow the user's will exactly. This is mainly due to the variation in accuracy of the human power detection device.

[0004] In order to avoid the above-mentioned problem, human power is
It has been proposed to provide a so-called dead zone width in which auxiliary power is not supplied even when human power is supplied in the auxiliary power characteristic. However, for each of the pair of left and right drive wheels,
Alternatively, in the case of a wheelchair provided with an auxiliary power motor only on one side, it is considered that there is a problem in that the supply start condition of the auxiliary force is determined on the side where the human power exceeds the dead zone width.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and in a case where each of the left and right driving wheels or only one of them is provided with an auxiliary power motor, optimal supply of auxiliary power is started. It is an object to provide a wheelchair with auxiliary power that can be performed.

[0006]

According to a first aspect of the present invention, a human power applied to one or both of two driving wheels disposed on the left and right sides in a traveling direction of a vehicle is determined based on the human power. In a wheelchair with auxiliary power, which performs forward and backward and turning operations of the vehicle by a combined force with the obtained auxiliary power, a human power detecting means for detecting human power applied to each of the drive wheels, and an auxiliary for generating auxiliary power Power source and auxiliary power control means for controlling the auxiliary power source so as to output the auxiliary power to the other or both drive wheels when human power to one of the left and right drive wheels exceeds a predetermined dead zone width. It is characterized by having.

According to a second aspect of the present invention, there is provided a wheelchair with auxiliary power similar to the first aspect, wherein human power detection means for detecting human power applied to each of the driving wheels, an auxiliary power source for generating auxiliary power, and And auxiliary power control means for controlling the auxiliary power source so as to output the auxiliary power to one or both of the driving wheels when the resultant force of the human power to the right driving wheel exceeds a predetermined dead zone width. Features.

According to a third aspect of the present invention, in the first or second aspect, a dead zone width control means for changing the dead zone width is provided.

According to a fourth aspect of the present invention, in the third aspect, the dead zone width control means sets the dead zone width to an assist waiting width N when the power is turned on and when no human power is input for a predetermined time.
1 and an assist width N2, and N1> N2.

[0010]

According to the first aspect of the present invention, when the human power to one of the left and right driving wheels exceeds a predetermined dead zone width, auxiliary power is output to both driving wheels. In this case, the auxiliary power to the left and right driving wheels can be simultaneously and smoothly supplied, and the problem that the vehicle is easily turned by applying the driving force can be avoided.

In the case where the auxiliary power is output to the other drive wheel when the human power to one of the left and right drive wheels exceeds a predetermined dead zone width, the drive motor is provided only on one side. Even when a user with a disability in one arm uses the equipped model, there is an effect that the supply of assisting force can be started smoothly.

According to the second aspect of the present invention, the auxiliary power is output to one or both of the driving wheels when the resultant force of the human power to the left and right driving wheels exceeds a predetermined dead zone width. The supply of auxiliary power to the left and right wheels can always be started simultaneously irrespective of the degree of user's obstacle, and the problem that the wheelchair is easily turned by the supply of auxiliary power can be avoided.

According to the third aspect of the present invention, since the dead zone width control means for changing the dead zone width is provided, the dead zone width can be set according to the degree of the obstacle to the user, and the supply of the auxiliary power can be further reduced. There is an effect that can be started smoothly.

According to the fourth aspect of the present invention, the dead zone width is set to the assist waiting width N1 when the power is turned on and when there is no input of human power for a predetermined time, and the human power is temporarily reduced to the ast waiting width N1.
When the power exceeds 1, the assist width N2 is set, and N1> N2. Therefore, when the power is turned on, the assist power is started to be supplied only when the user applies human power exceeding the relatively large set N1. Thus, it is possible to confirm the user's intention that the auxiliary power is required, and it is possible to prevent the auxiliary power from being generated carelessly.

Since the assist width N2 selected after a human input exceeding the assist wait width N1 is once input is set small, there is an effect that a smooth assist operation can be performed depending on the input history state.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 13 are views for explaining a wheelchair with auxiliary power according to a first embodiment of the present invention. FIG. 1 is a side view of the wheelchair, FIG. 2 is a plan view of the wheelchair, and FIG. FIG. 4 is a front view showing a state in which a cover of a hub portion of the wheelchair of the wheelchair is removed, FIG. 5 is a cross-sectional view taken along line VV in FIG. 4, and FIGS. FIG. 10 is a system configuration diagram of the auxiliary power control device, and FIGS. 11 to 13 are characteristic diagrams for explaining the control operation.

The wheelchair with auxiliary power 1 according to the present embodiment comprises:
The existing folding manual wheelchair has an auxiliary power unit (Power Ass
ist System). The wheelchair 1 is configured such that wheels 2 as driving wheels are detachably attached to left and right sides of a vehicle body, and front and rear portions of a pipe frame-shaped frame 3 are movably supported by a pair of left and right casters 4 and wheels 2. I have.

At the center of the frame 3, a cloth seat 5 (see FIGS. 2 and 3) on which an occupant sits is stretched. As shown in FIG. 3, the frame 3 has a pair of front and rear cross members 3a, and the two X-shaped cross members 3a are pivotally connected at their intersections by a shaft 6.

Further, a pair of left and right handle arms 3b is provided upright at a rear portion of the frame 3, and the upper end of each handle arm 3b is bent rearward, and the bent portion has a grip 7 for an assistant. Is attached.

The handle arm 3b of the frame 3
A pair of left and right arms 3c extending horizontally from the intermediate height position to the front of the vehicle body have their front ends bent at substantially right angles and extend vertically downward, and the casters 4 are rotatably supported at their lower ends. The main switch 8 is attached to a part (upper part of the vertical part) of the right side (right side for the occupant seated in the seat 5) of the arm 3c. The front portions of a pair of left and right arms 3d disposed below the arm 3c extend obliquely downward toward the front of the vehicle body, and a pair of left and right steps 9 is provided at the extension end (front end). Installed.

The wheel 2 outputs a hand rim assembly 70 to which a rotational force (manpower) is applied by a user's hand and a motor driving force (auxiliary power) corresponding to the manpower input from the hand rim assembly 70. And a drive unit 20.

A boss 11 is screwed into the center of the wheel of the frame 3, and an axle 22 is fitted and inserted into the shaft of the boss 11, and is fixedly fastened by a nut 22a. The axle 22 has a hollow shape, and a shaft 23 is inserted into the shaft core so as to be movable in the axial direction. Both ends of the shaft 23 have a larger head 23 than the other parts.
a and 23b are respectively formed. Right head 23
a, a coil spring 24 is disposed inside the shaft 2.
3 is urged to the right with respect to the axle 22. Are accommodated in the axle 22 such that the balls 25,. Each ball 25 is slightly expanded from the outer periphery of the axle 22 by being pushed and expanded by the large diameter portion of the head 23 a of the shaft 23, so that the axle 22 does not come off the boss 11. Further, the shaft 23 is connected to the axle 2
By moving relatively to the left in the figure with respect to 2,
The small-diameter portion of the head 23a moves to the position of the ball 25, so that the ball 25 can move inward. This allows
The axle 22 can be pulled out of the boss 11 to the right in FIG.

The axle 22 penetrates and supports the center of a fixed plate 30 having a substantially bottomed cylindrical shape.
A detent member (not shown) is attached to the fixing plate 30. The detent member prevents the fixed plate 30 from rotating with respect to the frame 3 by engaging with the frame 3.

The axle 22 supports a hub 50 as a rotating member having a substantially cylindrical shape with a bottom through a bearing 51 so as to be rotatable. An internal gear 52 is fixed to the inner surface of the hub 50. An intermediate gear 36a integrally formed with the intermediate shaft 36 meshes with the internal gear 52, and the intermediate shaft 36 serves as a fixed member. Fixing plate 3
0 is rotatably supported on the bottom surface. The intermediate shaft 36
Is driven to rotate by a driving motor 31 (see FIG. 10) attached to the fixed plate 30 via an intermediate pulley 33 fixed thereto and a belt, and as a result, the hub 50 rotates.

On the hub 50, the hand rim assembly 70 is supported so as to be relatively rotatable by a predetermined angle. The hand rim assembly 70 has a function of transmitting the rotational force applied by the user to the hand rim 13 to the hub 50 and detecting the applied rotational force. Hereinafter, a configuration for detecting the rotational force applied by the user will be described.

In FIGS. 4 and 5, reference numeral 71 denotes a disk constituting a central portion of the hand rim assembly 70. The disk 71 has an inner ring 71a and an outer ring 71b connected by three spokes 71c. It has a structure and is connected to the hand rim 13 by three spoke pipes 15. The disk 71 is supported by a boss 50a of the hub 50 via a bush 55 so as to be relatively rotatable.

The spokes 71c, 7 of the disk 71
Between 1c, a potentiometer 72 is arranged, and is attached to the outer surface of the bottom portion 50b of the hub 50 so that the position in the radial direction can be adjusted. The input shaft 72a of the potentiometer 72 protrudes from the inner surface of the bottom portion 50b, and a lever 73 having a long hole 73a is attached to the protruding portion. The pin 53 fixed to the disk 71 is inserted into the long hole 73a of the lever 73. Under this configuration, when the relative angle between the hub 50 and the hand rim assembly 70 changes from the reference position, the input shaft 72a of the potentiometer 72 rotates, and the impedance changes according to the rotation angle.

A spring guide 54 is disposed in a rectangular hole 71d formed in the spoke portion 71c.
A coil spring 56 is accommodated and arranged in the spring guide 54. Both ends of the coil spring 56 are in contact with the inner edge of the rectangular hole 71d of the spoke portion 71c via the slider 57. When the hand rim assembly 70 is rotated relative to the wheel 2 with this configuration, the relative rotation angle is detected by a human power detection device described later.

Reference numeral 58 denotes a resin damper member that functions as a play between the hub 50 and the disk 71. The damper member 58 is mounted inside the convex portion 54a formed on the spring guide 54, faces the outer ring portion 71b of the disk 71, and comes into sliding contact with the outer ring portion 71b by tightening a bolt 58a. The play between the disk 50 and the disk 71 is prevented. Reference numeral 71e denotes a cover that covers the potentiometer 72 and the like, and FIG. 4 shows a state where the cover 71e is removed.

Reference numeral 100 denotes a controller to be described later, which is disposed on the inner surface of the bottom 30b of the fixing plate 30.

Next, the configuration of the human power detection device will be described. Reference numeral 80 denotes a differential rotary transformer, which includes an outer transformer 81 attached to the boss 30a at the center of the fixed plate 30 and a boss 50a at the center of the movable plate 50.
And an inner transformer 82 attached to the main body.

In the outer transformer 81, two winding grooves 83a and 83b are recessed on the outer peripheral surface of a cylindrical bobbin 83 made of a non-magnetic material and an insulating resin.
The primary coils 84a and 84b are wound around 3b.

In the inner transformer 82, two holding grooves 85a and 85b are formed on the outer peripheral surface of a cylindrical core 85 made of a magnetic material (for example, metal such as soft iron), and the holding grooves 85a and 85b are formed. Inside, bobbins 86 and 87 around which secondary coils 89a and 89b are wound are attached to winding grooves 86a and 87a made of resin and formed on the outer peripheral surface thereof.

The bobbins 86, 87b are 86b, 87b.
The slits 90 are terminals and 90 is a terminal.
The ends 89a ', 89b' of the next coils 89a, 89b are drawn out through the slits 86b, 87b,
It is wound around the terminal 90.

Since the outer transformer 81 does not have a core made of a magnetic material having a function of blocking an external magnetic field, it is desirable to arrange the outer transformer 81 so as to suppress magnetic imbalance caused by an external metal. In the present embodiment, the magnetic distance from the primary coil 84a to the bottom 50b of the hub 50 (the distance when magnetic effects are taken into account),
In order to make the magnetic distance from the primary coil 84b to the bottom 30b of the fixed plate 30 as uniform as possible, the center line D in the width direction of the outer transformer 81 is positioned on the fixed plate 30 side with respect to the center line B in the wheel width direction. It is displaced by the dimension C.

That is, generally, the center D in the width direction of the outer transformer 81 is made coincident with the center B in the wheel width direction. In this case, the distance from the primary coil 84a to the bottom 50b of the hub 50 is reduced by one. The difference from the distance from the next coil 84b to the bottom 30b of the fixed plate 30 increases.

The left and right potentiometers 72, 72
The human power to the left and right wheels 2, 2 detected by the controller 100 is transmitted via the left and right rotary transformers 80, 80 to the controller 100.
The controller 100 controls power supplied to the motor 31 according to a predetermined processing procedure so that auxiliary power corresponding to the human power is obtained.

Next, the control operation of the auxiliary power by the controller 100 will be described with reference to FIGS. Here, FIG. 10 shows a control operation of the left wheel 2. In addition, the present embodiment device auxiliary power control includes torque control,
That is, a current control method is adopted, in which a duty ratio is limited in a current control loop to limit the auxiliary power from the motor along the constant voltage characteristic. The constant voltage characteristic of the motor has a negative slope with respect to the rotation speed.

First, the dead zone width setting function 101
The dead zone width is set based on the history of human power FL, FR (input) applied to the hand rims 13, 13 of the left and right wheels 2, 2. Note that the dead zone width is a human power width in which no auxiliary power is output even when a human power is input, and has a main purpose of absorbing a variation in sensitivity in the human power detection device.

In the present embodiment, as shown in FIG. 11, the dead zone width is set by the dead zone setting function 101 as the dead zone width.
When the power is turned on and there is no input of human power for a predetermined time, the assist waiting width N1 is selected, and once the human power exceeds the ast waiting width N1, an assist width N2 having a smaller value is selected. Here, the reason why the assist waiting width N1 is set to be large is to confirm the user's will to require the auxiliary power, thereby preventing careless generation of the auxiliary power. And once the waiting time width N
After a human power exceeding 1 is input, the assisting width N2 is selected. The reason for setting the assisting width N2 to a small value is to ensure that a smooth assisting operation is performed.

Here, there are various modes in which the auxiliary power is generated by the input of the human power exceeding the dead zone width. For example, when the human power to one of the left and right wheels exceeds the dead zone width, the power is generated. When the combined force of human power on both wheels exceeds the dead band width, generating auxiliary power to one or the other, or both, the left and right wheels. Generates auxiliary power.

Regarding the setting mode of the dead zone width,
The present invention is not limited to two stages, and may be selectable in multiple stages. It is also possible to provide a changeover switch, an adjustment knob, and the like for changing the size by manual operation of the user. it can.

Next, an amplification ratio (auxiliary ratio) setting function 103
Thus, the assist ratio KL (see FIG. 11) set according to the degree of the user's obstacle or the like is selected. Then, the turning component setting function 104 obtains a turning torque iL as a component that generates a turning motion from the product of the left-hand human power FL and the assist ratio KL. Note that different values may be selected for the assist ratio between the left and right based on the difference between the left and right arm strengths of the user, and the like.

The center-of-gravity component setting function 105 obtains a center-of-gravity torque iG as a component that causes a straight-line motion from the product of the resultant force of the predetermined combined rate of the left human force FL and the right human force FR and the assist ratio KL.

The target torque iR is obtained by adding the turning torque iL and the center-of-gravity torque iG. Then, the target current iRE required to generate the target torque iR in the motor 31 by the current limiter 106
F is obtained, the target value iREF and the current detection sensor 11
The correction amount is obtained by the PID control circuit 107 based on the difference from the current iFB actually flowing detected at 0,
Further, a voltage check described later is performed by the duty limiter 108, and a predetermined duty ratio is output. Then, the control signal (duty ratio) is converted into an actual current by the bipolar power amplifier 109, and the auxiliary current is supplied to the motor 31 in this manner.

Here, the auxiliary current is set based on the magnitude of the human power, but does not become zero immediately after the supply of the human power is stopped. Is maintained, and then gradually reduced.

In the present embodiment, the upper limit voltage E 111 is set by the upper limit voltage setting function 111 and the lower limit voltage setting function 112.
1 and the lower limit voltage E2 are set, and the voltage obtained from the duty ratio in the duty limiter 108 is
The output is limited to values within the upper and lower limit voltages E1 and E2. Thereby, the rotation speed of the motor 31, that is, the vehicle speed is limited by the upper limit voltage and the lower limit voltage.

The upper limit voltage E1 and the lower limit voltage E2 increase as the sum of the input human power FL, FR increases (see FIG. 1).
3 (a)), the smaller the value, the smaller it is set (see FIG. 3 (b)). In FIG. 13, the upper limit voltage E1 defines the rotation speed of the motor, that is, the vehicle speed, and the target current iREF
Indicates that the motor torque is specified.

The upper limit voltage E1 and the lower limit voltage E2 are
A predetermined value (for example, the value shown in FIG. 13A) is set according to the magnitude of the human power. As shown in FIG. 12, for a predetermined time t1 after the input of the human power is stopped, The value at the time of human power stop (the value in FIG. 13A) is held, and thereafter gradually decreases to, for example, the value shown in FIG. 13B over time.

As a result, in the present embodiment, the motor 3
In a state from the fourth set vehicle speed V4 to the first set vehicle speed V1, the auxiliary power output from 1 is held at the target torque iREF set according to the input human power, and when the auxiliary power exceeds the first set vehicle speed V1. It gradually decreases as the vehicle speed increases, becomes substantially zero at the second set vehicle speed V2, and when the vehicle speed exceeds the second set vehicle speed V2, the motor 31 acts as a load.

The auxiliary power output from the motor 31 increases as the vehicle speed decreases when the vehicle speed falls below the fourth set vehicle speed V4. This is because, for example, when the vehicle speed is lower than V4, the auxiliary power is increased during the predetermined time t1 even if the input is stopped.
4 and gradually decreased thereafter.

As described above, in this embodiment, when the combined force of the human power on both the left and right wheels exceeds the dead zone width, the auxiliary power is generated on both the left and right wheels. Irrespective of the degree of the obstacle, the supply of the auxiliary power to the left and right wheels can always be started at the same time, and the problem that the wheelchair turns too much due to the supply of the auxiliary power can be avoided.

It should be noted that, when human power to either the left or right wheel exceeds the dead zone width, auxiliary power to both the left and right wheels may be generated. The supply of the auxiliary force can be started simultaneously on the left and right sides, and the same effect as the above case can be obtained.

When the human power to one of the left and right wheels exceeds the dead zone width, the supply of the auxiliary power from the motor provided only to one of the wheels can be started.

Furthermore, in this embodiment, the dead zone width is set to the assist waiting width N1 when the power is turned on and when no human power is input for a predetermined time, and when the human power once exceeds the ast waiting width N1, the assist dead zone is set. With two steps of width N2,
In addition, since N1> N2, when the power is turned on, the auxiliary power is started to be supplied only when the user applies a human power exceeding the relatively large set N1, and the user needs the auxiliary power. Can be confirmed, and careless generation of auxiliary power can be prevented.

Once a human power exceeding the assist waiting width N1 is input, the assisting width N2 is selected. However, since the assisting width N2 is set to a small value, a smooth assist operation is performed depending on the input history state. It can be performed.

The dead zone width can be adjusted by the user using an external switch or an adjustment knob, and in this case, the dead zone width can be adjusted according to the degree of obstacle to the user. There is an effect that the setting can be performed and the supply of the auxiliary power can be started more smoothly.

In the present embodiment, the upper limit voltage E1 supplied to the motor 31 is limited to a value corresponding to human power. Therefore, the vehicle speed is limited by the upper limit voltage E1, and the vehicle speed is excessively increased. Can be avoided. When the vehicle speed exceeds the second set vehicle speed V2, the motor 31 becomes a load.
The problem that the vehicle speed is too high even on a downhill can be avoided.

Further, the target current iREF and the upper limit voltage E1 are maintained at the magnitude at the time of supplying the manual power for a predetermined time t1 after the supply of the human power F is stopped, and thereafter, are controlled to be small as time passes. Therefore, for example, when climbing a hill, it is possible to avoid a problem that the speed is suddenly decelerated as soon as the supply of the human power is stopped, or that the motor drive system becomes a load after the supply of the human power.

Further, when the vehicle speed is lower than the fourth set vehicle speed V4, the auxiliary power is increased in accordance with the decrease in the vehicle speed. Therefore, for example, the wheelchair is stopped midway on a slope without supplying human power. It is possible to improve usability, such as taking out a wallet in the middle of a slope. In this case, the time during which the slope can be stopped depends on the setting of the upper limit voltage holding time t1, and when the time elapses, the auxiliary power gradually decreases.

In the first embodiment, the auxiliary power is limited by limiting the upper limit voltage E1 and the lower limit voltage E2 of the motor. As a result, the vehicle speed is controlled. However, the target vehicle speed is set. The vehicle speed may be controlled based on the difference between the target vehicle speed and the detected vehicle speed. FIG. 14 is a diagram showing the second embodiment as described above. In the drawing, the same reference numerals as those in FIG. 10 indicate the same or corresponding parts.

In this embodiment, the upper limit speed setting function 21
1, the human power F input by the lower limit speed setting function 212
Upper limit speed ω1 and lower limit speed ω2 are set based on L and FR. Note that the upper limit speed ω1 is the second speed ω1 in FIG.
It corresponds to the set vehicle speed V2, and the lower limit speed ω2 is the fourth speed.
It corresponds to the set speed V4.

The vehicle speed calculating means 213 determines the wheel speed ωL based on the duty ratio output from the duty limiter 108, the current from the current detection sensor 110, the power supply characteristics, the motor constant of the motor 31, and the like.
Is calculated. Although a mechanical vehicle speed sensor can be separately provided, the system of this embodiment is more advantageous in terms of cost, weight, arrangement space, and the like.

Then, the center-of-gravity speed ωG is obtained by halving the sum of the left wheel speed ωL and the right wheel speed ωR.
The center-of-gravity speed ωG is compared with the upper limit speed ω1 and the lower limit speed ω2. When the center-of-gravity speed ωG is higher than the upper limit speed ω1, the current −i1 to be reduced according to the difference is determined by the gain applying functions 214 and 215, and when the center-of-gravity speed ωG is lower than the lower limit speed ω2, the current −i1 corresponds to the difference. Then, a current + i2 to be increased is obtained. The increase current + i2 and the decrease current -i1 are added to the obtained current corresponding to the turning torque and the center-of-gravity torque to obtain the target current iREF.

The same effects as those of the first embodiment can be obtained in the second embodiment as well, but furthermore, the usable range of the duty ratio in the PWM control is wide, and the system abnormality can be detected. There is.

That is, in the first embodiment, since a duty ratio is limited, only a part (for example, about 70%) of the entire duty ratio can be used. However, in the second embodiment, the use of the full duty ratio is not possible. It is possible. Further, in the second embodiment, since the target current value itself is corrected and controlled, if the difference between the target current value and the detected current value is equal to or larger than a predetermined value, it can be determined that the system itself is abnormal. .
On the other hand, in the first embodiment, since the upper limit and lower limit voltages are provided, for example, in an operation state limited to the upper limit voltage E1, there is a large difference between the target current value and the detected current value. Since it is assumed, a system abnormality cannot be detected from the difference between these current values.

In the first and second embodiments, the auxiliary power is set to zero at the second set vehicle speed V2, and the motor 31 acts as a load as the vehicle speed increases beyond the second set vehicle speed V2. However, FIGS. 15 and 16 show the second
FIG. 10 is a diagram showing a third embodiment in which the motor 31 acts as a load when the vehicle speed increases beyond a third set vehicle speed V3 which is higher than the set vehicle speed V2.
14 denote the same or corresponding parts.

In the third embodiment, the set vehicle speed calculation function 2
16, the human power F applied to the left and right drive wheels 2, 2
First to fourth set vehicle speeds V1 to V4 are calculated based on L and FR. In this case, the first to fourth set vehicle speeds V1 to V
4 is set larger as the human power is larger, and set smaller as the human power is smaller.

The center-of-gravity component setting function 105 calculates the center-of-gravity torque iG based on the calculated first to fourth set vehicle speeds V1 to V4 and the detected center-of-gravity speed ωG, and determines the target current iREF.

In this case, the target current iREF is determined such that when the center of gravity speed ωG is in the fourth to first set vehicle speeds V4 to V1, auxiliary power corresponding to human power is obtained. When the vehicle speed is between the second set vehicle speeds V1 and V2, the assist power is determined to decrease as the vehicle speed increases, and when the vehicle speed is between the second and third set vehicle speeds V2 and V3, the auxiliary force is determined to be zero. It is determined that a larger load is generated as the vehicle speed increases beyond the third set vehicle speed V3.

[Brief description of the drawings]

FIG. 1 is a side view of a wheelchair with auxiliary power according to a first embodiment of the present invention.

FIG. 2 is a plan view of the wheelchair.

FIG. 3 is a rear view of the wheelchair.

FIG. 4 is a front view showing a state where a cover of a hub portion of a wheel of the wheelchair is removed.

FIG. 5 is a sectional view taken along line VV of FIG. 4;

FIG. 6 is a front view of a rotary transformer portion of the wheelchair.

FIG. 7 is a sectional side view of a rotary transformer portion of the wheelchair.

FIG. 8 is a side view of a rotary transformer portion of the wheelchair.

FIG. 9 is a perspective view of a rotary transformer portion of the wheelchair.

FIG. 10 is a configuration diagram of a system showing a control operation of auxiliary power of the wheelchair.

FIG. 11 is a characteristic diagram of the human power and the output torque.

FIG. 12 is a characteristic diagram showing a temporal change of an upper limit voltage in the control operation.

FIG. 13 is a vehicle speed-motor torque characteristic diagram in the control operation.

FIG. 14 is a configuration diagram of a system showing a control operation of an auxiliary power according to a second embodiment of the present invention.

FIG. 15 is a configuration diagram of a system showing a control operation of an auxiliary power according to a third embodiment of the present invention.

FIG. 16 shows vehicle speed in the control operation of the third embodiment.
It is a motor torque characteristic diagram.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Wheelchair 2 Wheel (drive wheel) 31 Motor (auxiliary power source) 72 Potentiometer (human power detection means) 100 Controller (auxiliary power control means, dead zone width control means) N1 Assist waiting width (dead zone width) N2 Assist width (dead zone) width)

Claims (4)

[Claims] 1. A vehicle according to claim 1, wherein a combined force of a human power applied to one or both of two driving wheels disposed on the left and right sides in a traveling direction of the vehicle and an auxiliary power obtained based on the human power. In a wheelchair with auxiliary power configured to perform forward and backward and turning operations, a human power detection unit that detects human power applied to each of the drive wheels, an auxiliary power source that generates auxiliary power, and one of left and right Auxiliary power control means for controlling the auxiliary power source so as to output the auxiliary power to the other or both drive wheels when human power to the drive wheels exceeds a predetermined dead zone width. Wheelchair. 2. The vehicle according to claim 1, further comprising: a human power applied to one or both of two driving wheels disposed on the left and right sides in a traveling direction of the vehicle, and a combined power of an auxiliary power obtained based on the human power. In a wheelchair with auxiliary power adapted to perform forward and backward and turning operations, a human power detecting means for detecting human power applied to each of the drive wheels, an auxiliary power source for generating auxiliary power, and a left and right drive wheel. Auxiliary power control means for controlling the auxiliary power source so as to output the auxiliary power to one or both drive wheels when the resultant force of the human power exceeds a predetermined dead zone width. wheelchair. 3. The wheelchair with auxiliary power according to claim 1, further comprising a dead zone width control means for changing the dead zone width. 4. The apparatus according to claim 3, wherein the dead zone width control means sets the dead zone width to an assist waiting width N1 when the power is turned on and when no human power is input for a predetermined time, and that the human power is N1.
The assisting wheelchair, characterized in that the width at the time of assisting after exceeding N2 is N2 and N1> N2.