JPH0938144A - Auxiliary driving device for manual traveling vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable stable auxiliary drive even in the case of applying to a wheelchair by dividing the differential output of detected manual torque sampled in a prescribed period and preceding sampling output into N and controlling the auxiliary driving torque of an electric motor with the output corresponding to the provided value. SOLUTION: The output of a manual torque detection part 102 is sampled in the prescribed period and taken in. A calculation part 107 calculates the auxiliary driving torque corresponding to this input torque detected output, speed detected output from a speed detection part 105 and the manual driving torque from output characteristics to be stored in an ordinary output characteristic storage part 106 by sampling it in the prescribed period. At a transformation part 108, the calculated auxiliary driving torque values are updated and stored two by two, and its difference is divided into N and transformed as auxiliary driving force for each 1/N cycle. A motor control part 104 controls the driving motor so that this transformed auxiliary driving torque can be outputted to an electric driving part 103.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auxiliary drive device for a human-powered vehicle, for example, an auxiliary drive device for a human-powered vehicle in which a human-powered drive system provided with an electric motor is also provided.

[0002]

2. Description of the Related Art Conventionally, inpatients, persons with disabilities, who cannot walk
Elderly people, depending on the difficulty of walking and the needs of caregivers,
They used either a manual wheelchair (rear wheel drive type folding wheelchair) for the purpose of self-driving by a user or an electric wheelchair for the purpose of electric power running. For example, a manual wheelchair that can be driven by a hand rim has a minimum space for turning and can be folded and placed near the user, so that it is commonly used in hospitals and the like, but it can be used uphill. The force applied to the hand rim increases in places where there are steps and steps, and it is necessary to assist the caregiver each time.

In addition, the conventional electric wheelchair uses no human-powered driving force at all, and can be driven by the electric-powered driving force, so that a person with limited limbs can drive the vehicle, but the power consumption of the battery mounted on the vehicle body is large. Therefore, it was necessary to use a battery having a large capacity (for example, a lead storage battery). In addition, there is a problem that the radius of travel in turning is larger than that of a manual wheelchair, and operability is poor in a narrow space. Therefore, by incorporating the auxiliary drive device in the conventional manual wheelchair, while taking advantage of the manual wheelchair, the load is lighter even in an uphill place or a place with a step, and it is smaller than the battery of the conventional electric wheelchair. Expectations are being placed on the development of an auxiliary drive unit for wheelchairs that can use these batteries.

Conventionally, as a human-powered driving device capable of traveling with an auxiliary driving force of an electric motor, as described in JP-A-4-100790, a human-powered driving system and an electric-motor driving system are provided in parallel, It is known that a load applied to a drive system due to human power is detected to control an auxiliary drive force of an electric motor.

[0005]

However, when the human-powered drive device disclosed in Japanese Patent Laid-Open No. 4-100790 is applied to a vehicle body such as a wheelchair that is not stable in the front-rear direction (driving direction), for example, a start At this point, when a rapid human-powered drive torque is applied, the auxiliary drive torque can be delayed for a certain period of time, but it is not configured so that soft output is possible. Become.

The present invention has been made in consideration of the above circumstances. For example, the auxiliary drive torque for a sudden human-powered drive torque is softly output, and stable auxiliary drive is possible even when applied to a wheelchair. An auxiliary drive device for a human-powered vehicle is provided.

[0007]

FIG. 1 is a block diagram showing the basic configuration of the present invention. In FIG. 1, the present invention relates to a human power drive unit 101 for driving wheels by human power, a human power torque detection unit 102 for detecting a driving torque by human power,
Electric drive unit 10 for auxiliary driving of wheels by an electric motor
3 and a motor control unit 1 for generating an auxiliary drive torque in the electric drive unit in accordance with the detection output of the manual torque detection unit 102.
In the human-powered vehicle equipped with 04, the output of the human-power torque detection unit 102 is sampled and taken in at a predetermined cycle,
A human-powered vehicle characterized in that an output corresponding to a value obtained by dividing the difference output between the output and the immediately preceding sampling output by N is generated, and the auxiliary drive torque of the electric motor is controlled according to the divided output. It is an auxiliary drive device.

A speed detector 10 for detecting the rotational speed of the wheels.
5, and a steady output characteristic storage unit 10 in which the output characteristics of the auxiliary driving torque corresponding to the traveling speed and the human driving torque are stored in advance.
6, the human power torque detection output detected by the human power torque detection unit 102 and the speed detection output detected by the speed detection unit 105 are sampled at a predetermined cycle, and the steady output characteristic storage unit 1
The calculation unit 107 that calculates the auxiliary drive torque corresponding to the human-powered drive torque from the output characteristics stored in 06, and the value of the auxiliary drive torque calculated in a predetermined cycle is updated and stored for each two, and the difference is divided into N. A conversion unit 108 that converts the auxiliary drive torque for each 1 / N cycle is further provided, and the motor control unit 104 controls the electric motor so that the converted auxiliary drive torque is output to the electric drive unit 103. To do.

In the present invention, the human-powered vehicle means, for example, a bicycle, a wheelchair or the like which is driven by human power. The human-powered drive unit 101 means a device for rotationally driving the wheels by human power, and means a hand rim in a wheelchair. Manual torque detector 102
Is, for example, a pressure sensor, a magnetoresistive element, a strain gauge, a potentiometer, a differential transformer, which converts a mechanical pressure or a deformation amount according to a human-powered driving torque (human-powered driving force) applied from a hand rim to a driving wheel into an electric signal. Etc.

The auxiliary drive torque (auxiliary drive force) of the electric drive unit 103 means a motor drive torque generated in the electric motor. This electric motor is a permanent magnet excitation type DC brush motor, a brushless motor, a flat motor, or the like. Composed of. Speed detection unit 105 for detecting the rotation speed of the wheels
Is composed of a tacho generator, a photo coupler, a Hall IC, and the like. The motor control unit 104, the steady output characteristic storage unit 106, the calculation unit 107, and the conversion unit 108 include a CPU and RO.
It is composed of a microcomputer including an M, a RAM, an I / O port, a timer, and an A / D converter.

In particular, as the steady output characteristic storage unit 106, the ROM therein is used. In addition, the ROM is
A program that functions as the motor control unit 104, the calculation unit 107, and the conversion unit 108 is stored. Further, in the RAM, data processed by the CPU (for example, detection signal, calculated auxiliary drive torque, etc.) is updated and stored. As a drive power source for the electric motor of the electric drive unit 103, for example, 24 V of a rechargeable Ni-cd battery, 2.5
A DC power supply of about Ah or 5.0 Ah may be used. This DC power supply is further stabilized and used as a drive power supply for the above-mentioned components.

A start output characteristic storage unit 109 is further provided in which the output characteristic of the auxiliary drive torque corresponding to the human drive torque at the start of traveling is stored in advance, and the calculation unit 107 is provided.
Is configured to calculate an auxiliary drive torque corresponding to the human power drive torque from the human power torque detection output detected by the human power torque detection unit and the output characteristic stored in the start output characteristic storage unit 109 for a predetermined time at the start of traveling. Preferably. The start output characteristic storage unit 109 is composed of a ROM in the microcomputer.

A current detector 110 for detecting a drive current of the electric motor is further provided, and the motor controller 104 obtains a drive force from the drive current detected by the current detector 110 and matches the drive force with the auxiliary drive force. It is preferable that the electric motor is controlled so as to output the driving force. The current sensor 110 is composed of a shunt resistor, a hall element and the like. When the electric motor is PWM (Pulse Width Modulation) controlled, it can be used also as a rotation speed detection sensor of the electric motor by providing a circuit for detecting the back electromotive force output from the electric motor.

According to the present invention, the manual torque detector 102
Output is sampled at a predetermined cycle, an output corresponding to a value obtained by dividing the difference output between that output and the immediately preceding sampling output by N is generated, and the auxiliary drive torque of the electric motor is calculated according to the divided output. Control. In other words, the calculation unit 107 converts the human power torque detection output detected by the human power torque detection unit 102, the speed detection output detected by the speed detection unit 105, and the output characteristic stored in the steady output characteristic storage unit 106 into a human power drive torque. The corresponding auxiliary drive torque is sampled and calculated in a predetermined cycle, and further, the conversion unit 108 updates and stores two values of the auxiliary drive torque calculated in the predetermined cycle and divides the difference by N, It is converted as an auxiliary driving force for every N cycles. Then, the motor control unit 104 controls the electric motor so that the converted auxiliary drive torque is output to the electric drive unit 103. Therefore, the auxiliary drive torque can be softly output even if a rapid human-powered drive torque is applied to the wheels, so that stable auxiliary drive is possible when applied to a wheelchair.

Further, by further comprising a start output characteristic storage unit 109 in which the output characteristic of the auxiliary drive torque corresponding to the manpower drive torque at the start of traveling is stored in advance, the calculation unit 107 makes the calculation unit 107 at the start of traveling. For a predetermined time, the auxiliary driving torque corresponding to the human driving torque can be calculated from the human torque detection output detected by the human torque detecting unit 102 and the output characteristic stored in the start output characteristic storage unit 109. In particular, at the start of running and during normal running, the output characteristics storage unit for the auxiliary driving force with respect to the human driving force is used separately for calculation, so it is possible to output the auxiliary driving torque softly, which improves safety. improves.

Further, by further comprising the current detection unit 110 for detecting the drive current of the electric motor, the motor control unit 104 obtains the motor drive torque from the drive current detected by the current detection unit 110. The electric motor can be controlled so as to match the calculated auxiliary drive torque.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings. The present invention is not limited to this. The auxiliary drive device for a human-powered vehicle according to the present invention is mainly applied to a wheelchair to enable stable auxiliary drive.

FIG. 2 is an external view of a wheelchair to which the auxiliary drive device of the human powered vehicle according to the present invention is applied. In FIG. 2, FIG. 2A is a plan view of the wheelchair, FIG. 2B is a side view of the wheelchair, and FIG. 2C is a rear view of the wheelchair. FIG.
(D) is an external view of a battery. FIG. 2E is an external view of the operation panel. 1 is a wheelchair main body. Reference numeral 2 is a drive wheel for driving the wheelchair body 1, and drive wheels 2a, 2b are provided on the left and right
Is provided. 3 is a drive wheel 2a on the left and right by human power,
It is a hand rim (manual drive unit) that drives 2b, and hand rims 3a and 3b are provided on left and right drive wheels 2a and 2b. Reference numeral 4 denotes a frame, which is composed of a left frame 4a, a right frame 4b, a plow 4c, and the like.

Numeral 5 is a universal wheel, which is the left and right frames 4a, 4
Free wheels 5a and 5b are provided at the lower end of b. 6 is a grip, and the grips 7 are provided on the upper end portions of the left and right frames 4a and 4b.
a and 7b are provided. A seat unit 7 supports a user's body, and includes a seat 7a, a backrest 7b, left and right elbow pads 7c1-7c2, left and right footrests 7d1-7.
It consists of d2 and other accessories.

Reference numeral 8 denotes a hub provided on the rotary shafts of the drive wheels 2a and 2b. Inside the left and right hubs 8a and 8b, a human torque sensor (human torque detecting section), a speed sensor (speed detecting section), which are not shown, Each detection unit of the current sensor (current detection unit), an electric drive unit including an electric motor, a speed reduction mechanism, a clutch, a control circuit board on which a microcomputer is mounted, and the like are incorporated. 9 is a battery (DC power supply)
And, for example, rechargeable NiCd (Ni-cd)
It is composed of a battery of about 24 V, 2.5 Ah or 5.0 Ah, and is provided on the side faces of the left and right frames 4a, 4b or the backrest 7b (see FIG. 2 (d)). Reference numeral 10 denotes an operation box having an ON / OFF switch for turning ON / OFF the power supply of the battery 9 and an LED for displaying the ON / OFF state, and is provided, for example, near the elbow pad 7c (FIG. 2 (e)). ,reference). In FIG. 2, the drive wheel 2
Although a manual brake for braking or locking a and 2b is not shown, it is provided in front of the drive wheels 2a and 2b.

FIG. 3 is a block diagram showing a control circuit of a wheelchair to which the auxiliary drive device in the human powered vehicle of the present invention is applied. In FIG. 3, 301a is the left hand rim 3a.
Is a human-power torque sensor for detecting forward / backward human-power drive torque (human-power drive force), and reference numeral 301b is a human-power torque sensor for detecting forward / backward human-power drive force applied to the right hand rim 3b. It is preferable to use a variable inductance type pressure sensor as the manual torque sensors 301a and 301b, since it is possible to accurately convert a small mechanical displacement into an electric signal without contact. 30
2a is an electric motor that drives the left drive wheel 2a,
302b is an electric motor that drives the right drive wheel 2b. For the electric motors 302a and 302b, it is preferable to use a permanent magnet excitation type DC brush motor in terms of rotation speed, power and the like.

Reference numeral 303a is a speed sensor for detecting the rotational speed of the left drive wheel 2a (or electric motor 302a), and 303b is the right drive wheel 2b (or electric motor 30).
2b) is a speed sensor for detecting the rotation speed. These speed sensors 303a and 303b are photocouplers and Hall I
It is composed of C etc. The traveling speed S (km / h) of the wheel is
The rotational speed (n / s) of the drive wheel (or the electric motor), the radius r of the drive wheel, and S = 2πrn / 3600 are used for the calculation.

Reference numeral 304a is a current sensor for detecting the drive current Ia of the left electric motor 302a, and 304b is a current sensor for detecting the drive current Ib of the right electric motor 302b. The current sensors 304a and 304b are
It consists of a shunt resistor and a Hall IC. The drive torques Fa and Fb of the electric motors 302a and 302b are Fa =
K · Ia, Fb = K · Ib (K is a constant).

Reference numeral 305 is a controller, which is a CPU, R
It is composed of a microcomputer consisting of an OM, a RAM, an I / O port, a timer, an A / D converter, and a counter, and has a motor control unit, a steady output characteristic storage unit (steady output characteristic table), a start output characteristic storage unit (start output characteristic). It functions as a table), a calculation unit, and a conversion unit. The start output characteristic table that pre-stores the start output characteristics of the auxiliary drive torque with respect to the human power drive torque at the time of traveling start, and the steady output characteristic table that pre-stores the output characteristics of the auxiliary drive torque that corresponds to the traveling speed and the human drive torque are
It consists of ROM. Further, the ROM stores programs that function as a motor control unit, a calculation unit, and a conversion unit. Further, the data processed by the CPU is updated and stored in the RAM.

Further, the A / D converter samples the forward / backward human-power driving force signals detected by the human-power torque sensors 301a and 301b at a predetermined cycle to perform A / D conversion.
(Analog-digital) conversion to convert to forward / reverse driving force data. Current sensors 304a, 304b
Similarly, the drive currents Ia and Ib detected by Sampling the drive current signal are also sampled at a predetermined cycle, A / D (analog-digital) converted, and converted into electric drive torque data of the electric motor. The counter is a speed sensor 303a,
The rotation speed signal detected by 303b is counted and converted into traveling speed data.

Reference numeral 306a is a motor drive circuit for driving the left electric motor 302a, and 306b is a motor drive circuit for driving the right electric motor 302b. The motor drive circuit 306a (306b) includes a bridge of switching transistors Q1a to Q4a (Q1b to Q4b) and diodes D1a to D for protecting the bridge.
4a (D1b to D4b).

Reference numeral 307a is a forward drive circuit for the motor drive circuit 306a to drive the left electric motor 302a forward, and 307b is a forward drive circuit for the motor drive circuit 306b to drive the right electric motor 302b forward. . When the forward drive circuit 307a (307b) receives the forward drive signal from the controller 305, for example, the transistors Q1a and Q4a (Q1b and Q4b) are turned on to drive the electric motor 302a (302b) in the clockwise direction. At this time, the controller 305 determines the auxiliary driving torque from the human power torque detection signal detected by the human power torque sensor 301a (301b), and the current sensor 3
Drive current Ia detected by 04a (304b)
The forward drive torque of the electric motor is calculated from (Ib), and PWM (pulse width modulation) control is performed so that the auxiliary drive torque and the forward drive torque match.

Reference numeral 308a is a reverse drive circuit for the motor drive circuit 306a to drive the left electric motor 302a in reverse, and 308b is a reverse drive circuit for the motor drive circuit 306b to drive the right electric motor 302b in reverse. . When the reverse drive signal is received from the controller 305, the reverse drive circuit 308a (308b) turns on the transistors Q2a and Q3a (Q2b and Q3b) to drive the electric motor 302a (302b) counterclockwise, for example. At this time, the controller 305 determines the auxiliary drive torque from the manual torque detection signal detected by the manual torque sensor 301a (301b) and the drive current Ia detected by the current sensor 304a (304b).
The backward drive torque of the electric motor is calculated from (Ib), and PWM (pulse width modulation) control is performed so that the auxiliary drive torque and the backward drive torque match.

Reference numeral 309 is a dynamic braking circuit for dynamic braking the electric motors 302a and 302b. Dynamic braking circuit 309
When the stop signal is received from the controller 305, the electric motor 302a is controlled, for example, by ON / OFF controlling the transistors Q3a and Q4a (Q3b and Q4b) for a predetermined time.
(302b) is dynamically braked. Reference numeral 310 denotes a battery, which is composed of, for example, a rechargeable Ni-cd battery having a voltage of about 24 V, 2.5 Ah, or 5.0 Ah. Reference numeral 311 is a constant voltage circuit, which is composed of, for example, a 5V regulator IC, and a battery voltage of 24V is 5V.
The constant voltage of the controller 305, human torque sensor 301a, 301b, speed sensor 303a, 303
b, etc. An ON / OFF switch 312 turns ON / OFF the power supply of the battery 310, and when turned ON, supplies 24V voltage to the switching circuits 306a and 306b, and the LED lamp 313 is turned on.

Here, the control circuit of the wheelchair enables reversible rotation driving of the electric motor 302a (302b),
Although the auxiliary drive can be performed during the forward traveling and the backward traveling, the control circuit can be simplified so that the auxiliary driving can be performed only during the forward traveling. Also,
An electromagnetic clutch for electrically connecting the reduction mechanism of the electric motor 302a (302b) and the transmission mechanism of the driving wheels may be provided so that the electric wheel 302 can be used as a normal wheelchair when the power is turned off.

FIG. 4 is a flow chart showing the auxiliary drive torque calculation processing of the present invention. In FIG. 4, Step 401: Human torque sensor 301a (301
The forward / reverse manpower drive torque signal detected in b) is read (sampling) at a predetermined cycle T and converted into forward / reverse manpower drive torque data (for example, T = 100 m).
S). Step 402: The forward / reverse rotational speed signal detected by the speed sensor 303a (303b) is read (sampling) at a predetermined cycle T and converted into forward / reverse traveling speed data. Step 403: A timer measures to determine whether or not a predetermined time has elapsed since the wheelchair was started to drive.

Step 404: A predetermined time (for example, 2
Second), reference is made to a start output characteristic table in which the output characteristics of the auxiliary driving torque with respect to the human driving torque at the start of traveling are stored in advance, and the auxiliary driving torque (assist amount) is calculated from the human driving force data obtained in step 401. Is calculated in synchronization with a predetermined cycle T. FIG. 5 is an explanatory diagram showing the output characteristics of the auxiliary driving force of the start output characteristic table.
In FIG. 5, MAX of the ratio of the auxiliary driving force to the human driving force is 1 for 0 to 2 seconds at the time of starting the forward / reverse traveling.
It is increasing linearly. The ratio of the auxiliary driving force to the human driving force and the predetermined time at the start of traveling can be set by an external DIP switch.

Step 405: Predetermined time (for example, 2
Second), the steady output characteristic table in which the output characteristics of the auxiliary driving torque corresponding to the traveling speed and the manpower-driven torque are stored in advance is referred to, and the human-powered driving torque data obtained in step 401 and the traveling obtained in step 402 are referred to. The auxiliary drive torque (assist amount) is calculated from the speed data in synchronization with the predetermined cycle T. FIG. 6 is an explanatory diagram showing the output characteristic of the auxiliary drive torque of the steady output characteristic table. In FIG. 6, for example, when the forward speed (running speed) is 4 km / h or less, it is constant at a ratio of auxiliary driving torque / manual driving torque = 1, 4 to 6
The auxiliary drive torque is linearly reduced between km / h. In addition, the reverse speed (travel speed) is 0 to -6 km / h.
The auxiliary drive torque (amount of assist) is linearly reduced during the period.

Step 406: The assist amount A calculated last time and the assist amount B calculated this time are updated and stored in the RAM in synchronization with the constant period T. Step 407: The magnitudes of the previously calculated assist amount A and the presently calculated assist amount B are compared and determined. Step 408: When the assist amount B calculated this time is larger than the assist amount A calculated last time, the change amount, C = BA, is calculated. Step 409: When the assist amount B calculated this time is smaller than the assist amount A calculated last time, the change amount, C = A−B, is calculated. Step 410: C / N = D is calculated, and the change amount C is divided into N equal parts. Here, N is a numerical value that divides the constant period into N equal parts (for example, N = 5).

Step 411: T / N is converted into an assist amount by adding / subtracting a change amount D equally divided into N to the assist amount A.
Output to the motor control unit (inside the controller) every cycle. Step 412: It is determined whether or not | B−A | = C = ND, and step 411 is performed until | B−A | = C.
Return to and repeat. Step 413: It is judged whether or not A = B = 0,
If A = B = 0, the process proceeds to step 414, where A = B =
If it is not 0, the process returns to step 401 and finally converted into the assist amount obtained in step 411.

Step 415: If the assist amount becomes 0, it is judged whether or not the traveling speed = 0, and the traveling speed =
If it is 0, the traveling is stopped and the calculation of the assist amount is finished. If the traveling speed is not 0, the process returns to step 401 and steps 401 to 414 are repeated. The auxiliary drive torque calculation processing of steps 401 to 414 is performed in parallel for the electric motors 302a and 302b. Further, the same step processing is applied to the forward traveling or the backward traveling. Since the auxiliary drive torque can be softly output even when a rapid human-powered drive torque is applied, stable auxiliary drive is possible when applied to a wheelchair. In particular, at the start of running and during normal running, the output characteristic table of the auxiliary drive torque with respect to the human-powered drive torque is used separately for calculation, so it is possible to output the auxiliary drive torque softly, improving safety. To do.

FIG. 7 is an explanatory diagram showing output conversion of the assist amount according to the present invention. In FIG. 7, (1) in FIG. 7 is the assist amount calculated for each predetermined cycle T, and the step 4 in FIG.
01, 402, 405. Conventionally, in a bicycle that can run with an auxiliary drive torque of an electric motor, when a sudden human-power drive torque is applied, the amount of change is not adjusted, and the electric motor is controlled simply by obtaining the auxiliary drive torque with respect to the human-power drive torque. It was (2) in the figure is the assist amount converted for each T / N cycle, and the step 4 in FIG.
It is calculated from 01 to 411. While the value of the auxiliary driving force calculated in the predetermined cycle T is updated and stored in the RAM for every two times, the amount of change is equally divided into N and converted into the auxiliary driving force for every T / N cycle to the motor control unit. Since the output is performed, the motor control unit can control the electric motor with the auxiliary driving force whose change amount is adjusted, even if a rapid human-powered driving torque is applied. Therefore, when the travel assistance drive device of the present invention is applied to a wheelchair, stable travel assistance drive is possible.

FIG. 8 is an explanatory diagram showing a signal processing circuit of the manual torque sensor and its signal waveform. In FIG. 8, the human power sensor is a variable inductance type sensor including a coil 801 and a ferrite 802, and a ferrite 80
2 is slid in parallel with the coil 801 so that it can be moved closer to or farther from the coil 801 in proportion to the magnitude of the driving force of human power. A pulse voltage having a waveform as shown in FIG. 7A is applied from the controller 305 to the coil 801. In addition, the ferrite 802 and the coil 801
, The inductance of the coil 801 changes, and the output becomes a broken line having a waveform as shown in FIG. The output pulse voltage (B) is supplied to the integration circuit 803.
Is integrated, converted into a waveform as shown in FIG. 9C, converted into a direct current, amplified by the next amplifier 804, and input to the I / O port of the controller 305 as a human power driving signal.

The CPU of the controller 305 takes in the human-powered drive torque output in a predetermined cycle, A / D-converts it, and converts it into human-powered drive torque data. When detecting the forward / reverse human-power drive torque, two human-power torque sensors and two signal processing circuits may be provided, but one ferrite 8
The slide area of 02 can be divided into two areas, forward / reverse, and accordingly, the DC voltage level of the detection signal is also divided into two areas so that the forward driving force and the backward driving force signal can be determined. You may comprise.

Further, in this embodiment, the amount of change in human power changed in one sampling period is divided into N equal parts, and the value is gradually added to perform the soft start. However, for example, the change is changed in two or more sampling periods. The amount may be divided into 2N and 3N, and the start may be performed more gently. With this configuration, the assist force can be made to respond with a delay to the human power, and therefore the motor is driven with a slight delay from the human power. Therefore, when the human power gradually increases, the human power is assisted with a smaller assist force, and when the human power reaches the maximum, the assist amount is smaller than the human power.
Then, when the human power starts to decrease, the assisting force from the motor becomes maximum, so that smooth assisted traveling can be realized.

[0041]

According to the present invention, the auxiliary drive torque can be softly output even when a rapid human-powered drive torque is applied. Therefore, when applied to a wheelchair, stable auxiliary drive can be performed. In particular, at the start of running and during normal running, the output characteristic table of the auxiliary drive torque with respect to the human-powered drive torque is used separately for calculation, so it is possible to output the auxiliary drive torque softly, improving safety. To do.

[Brief description of drawings]

FIG. 1 is a block diagram showing a basic configuration of the present invention.

FIG. 2 is an external view of a wheelchair to which the auxiliary drive device of the human powered vehicle according to the present invention is applied.

FIG. 3 is a block diagram showing a control circuit of a wheelchair to which the auxiliary drive device in the human powered vehicle of the present invention is applied.

FIG. 4 is a flowchart showing an auxiliary drive torque calculation process of the present invention.

FIG. 5 is an explanatory diagram showing output characteristics of auxiliary drive torque in a start output characteristic table.

FIG. 6 is an explanatory diagram showing output characteristics of auxiliary drive torque of a steady output characteristic table.

FIG. 7 is an explanatory diagram showing output conversion of an assist amount according to the present invention.

FIG. 8 is an explanatory diagram showing a signal processing circuit of a manual torque sensor and its signal waveform.

[Explanation of symbols]

 1 wheelchair body 2 drive wheel 3 hand rim 4 frame 5 universal wheel 6 grip 7 seat unit 8 hub 9 battery 10 operation box 301a, 301b human torque sensor 302a, 302b electric motor 303a, 303b speed sensor 304a, 304b current sensor 305 controller 306a, 306b Motor drive circuit 307a, 307b Forward drive circuit 308a, 308b Reverse drive circuit 309 Power generation braking circuit 310 Battery 311 Constant voltage circuit 312 ON / OFF switch 313 LED lamp

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Kan, 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd.

Claims (5)

[Claims] 1. A human-powered drive unit for driving wheels by human power, a human-power torque detection unit for detecting drive torque due to human power, an electric drive unit for auxiliary driving of wheels by an electric motor, and a detection output of the human-power torque detection unit. Correspondingly, in a human-powered vehicle equipped with a motor control unit that generates an auxiliary drive torque in an electric drive unit, the output of the human-power torque detection unit is sampled and taken in at a predetermined cycle, and the difference between the output and the immediately preceding sampling output is sampled. An auxiliary drive device for a human powered vehicle, wherein an output corresponding to a value obtained by dividing the output by N is generated, and the auxiliary drive torque of the electric motor is controlled according to the divided output. 2. A speed detecting section for detecting a rotation speed of a wheel, a steady output characteristic storing section for storing beforehand an output characteristic of an auxiliary driving torque corresponding to a traveling speed and a human driving torque, and the human torque detecting section. A calculation unit that calculates the auxiliary driving torque corresponding to the human driving torque from the output characteristics stored in the steady output characteristic storage unit by sampling the detected human power torque output and the speed detection output detected by the speed detecting unit in a predetermined cycle, The motor control unit further includes: a conversion unit that updates and stores two values of the auxiliary drive torque calculated in a predetermined cycle, divides the difference by N, and converts the difference into an auxiliary drive torque for each 1 / N cycle. The auxiliary drive device for a human powered vehicle according to claim 1, wherein the electric motor is controlled so that the converted auxiliary drive torque is output to the electric drive unit. 3. A start output characteristic storage unit that stores in advance the output characteristics of the auxiliary drive torque corresponding to the human drive torque at the start of traveling, wherein the calculation unit is a human torque detection unit for a predetermined time at the start of traveling. The auxiliary drive device for a human-powered vehicle according to claim 2, wherein an auxiliary drive torque corresponding to the human-power drive torque is calculated from the human-power torque detection output detected by and the output characteristic stored in the start output characteristic storage unit. . 4. A current detection unit for detecting a drive current of the electric motor is further provided, wherein the motor control unit obtains a motor drive torque from the drive current detected by the current detection unit and matches the auxiliary drive torque. The auxiliary drive device for a human powered vehicle according to claim 1, wherein the electric motor is controlled so as to output a motor drive torque. 5. The auxiliary drive device for a human powered vehicle according to claim 1, wherein the auxiliary drive device is applied to a wheelchair.