JP3432966B2 - Control device for electric wheelchair - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric wheelchair control device for braking by controlling energization of a motor for driving wheels.

[0002]

2. Description of the Related Art As a control device as described above, the one disclosed in Japanese Patent Publication No. 4-49321 is known. In this control device, when an occupant operates an accelerator, an accelerator signal is issued, and a motor drive signal generation circuit that receives the accelerator signal generates a motor drive signal and causes the motor to rotate normally. Then, when the accelerator is brought to the stop position, the motor braking signal generation circuit operates to generate the motor braking signal. By this motor braking signal, a current for rotating the motor in the reverse direction instantaneously flows to the motor for braking.

Further, in this control device, when the accelerator reaches the stop position and the temporary operation is stopped at this position, the parking brake drive circuit is driven, and thereafter, the circuit for driving the motor and the circuit for braking are driven. Power supply is stopped.
As a result, it is possible to reduce the waste of electric power when the vehicle is parked or stopped.

[0004]

However, the parking brake driven by the above parking brake drive circuit is a mechanical parking brake. Therefore, in the above technique, since it is necessary to separately provide a mechanical parking brake, the total weight of the vehicle is increased, the amount of driving work is increased accordingly, and power is eventually lost. In addition, a large motor and a large capacity battery are required, which causes an increase in manufacturing cost.

The present invention has been made in consideration of the above circumstances, and is an electric wheelchair control device for braking by energization control, which reduces power loss when parking and stopping and is a mechanical parking brake. An object of the present invention is to provide a control device for an electric wheelchair that does not require the above.

[0006]

In order to solve the above problems, in an electric wheelchair control device according to the present invention, an electric wheelchair control device for controlling traveling of wheels of a wheelchair by a motor is provided. A speed control operator that outputs a travel command and a stop command in response to an operation, a controller that energizes and controls the electric power of the battery to the motor when the travel command is issued, and power on / off of the battery to the controller. A main switch which is turned off, one terminal connected to one end side of the motor, the other terminal connected to one electrode of the battery, and a common switch terminal connected to the other end of the motor ; Of the motor
It is provided in the power supply path and the amount of electricity supplied is controlled by on / off operation.
Comprising a switching unit for controlling I, wherein the controller, when the travel command is issued, to connect the common terminal and the other terminal of the changeover switch means Rutotomoni,
ON / OFF of the switching unit according to the traveling command
While controlling the time, when the stop command is issued,
Or when the main switch is turned off when connecting the common terminal and one terminal of the change-over switch means DOO
By the way, the switching unit is turned off, and after a lapse of a predetermined time.
Connect the common terminal and one terminal of the changeover switch means.
It is characterized by causing.

In this case, the controller is
It is preferable to start the on / off time control of the switching unit after the running command is issued and the common terminal of the changeover switch means is connected to the other terminal.

Further, it is preferable that the switching section is composed of a plurality of switching elements connected in an H bridge.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. A. Configuration of Embodiment First, FIG. 1 is a block diagram showing a circuit of an electric wheelchair control device according to an embodiment of the present invention. In the figure, reference numeral 1a is a main switch, 1b is a joystick (speed control operator), 2 is a battery, 3 is a DC motor (hereinafter referred to as "motor") for rotating wheels, and 4 to 7 are rotations of the motor 3. FET (switching element) for controlling
Is. In the figure, a parasitic diode existing in the FET is also shown.

In this embodiment, the battery 2 is made of Ni.
A battery in which a plurality of storage batteries such as Cd batteries are connected in series is used. As will be described later, the motor 3 and the FETs 4 to 7
Constitutes a voltage adjusting section (switching section) 8 which is an H-bridge circuit, and a relay (changeover switch means) 9 is interposed between the voltage adjusting section 8 and the battery 2. The relay 9 connects the battery 2 and the voltage adjusting unit 8 in the ON state shown by the broken line in the figure, and disconnects the electrical connection between the battery 2 and the voltage adjusting unit 8 in the OFF state shown by the solid line, and at the same time, the voltage adjusting unit. Directly connect both terminals of 8.

Reference numeral 11 represents a controller,
The controller 11 includes a CPU unit 12, a control power supply unit 13, a drive circuit 14, a memory (not shown), and the like.

The main switch 1a is turned on / off by an occupant. When the main switch 1a is on, the battery 2 and the controller 11 are electrically connected, and when the main switch 1a is off, the connection is released. The joystick 1b moves the wheels forward
It is provided for reverse operation and speed control, and when the occupant tilts the joystick 1b, a voltage corresponding to the tilt angle is output, and this voltage is converted into a tilt angle signal by an interface (not shown) or the like. In this way, the tilt angle signal takes a value corresponding to the tilt angle of the joystick 1b, and takes a positive value when the joystick 1b is tilted forward and a negative value when tilted backward. The neutral state is when the joystick 1b is not tilted in any direction, and the tilt angle signal is 0 in this state.

The main switch 1a and the joystick 1b are arranged on the same operation panel (not shown) so that an occupant of the electric wheelchair can easily operate them. The electric wheelchair is designed to travel by controlling the rotational speeds of the left and right wheels, and in practice, the motor 3 and the voltage adjusting unit 8 are provided one on each side. However, in the following description, one motor 3 is controlled to facilitate understanding.

Control power supply unit 13 of controller 11
By controlling the voltage of the battery 2, the CPU
A stable voltage is supplied to the unit 12 and the drive circuit 14.
The CPU unit 12 calculates an instruction speed at which the wheels should be rotated based on the tilt angle signal from the joystick 1b,
Based on this instructed speed, a PWM pulse, a gate block signal, and a relay on / off command signal, which are control signals, are output. Here, the PWM pulse is output to control a mutual time width of a gate signal and a gate signal, which will be described later, and to control a rotation direction and a speed of the motor 3, and the gate block signal is an output of all the gate signals ~. Is output to stop the energization from the battery 2 to the motor 3.

In this case, when the tilt angle signal is other than 0, that is, when the traveling command is issued, C
The PU unit 12 calculates the instructed speed, first outputs a relay-on signal, and after a predetermined time T1 (see FIGS. 2 and 3) elapses,
The gate block signal is released and a PWM pulse corresponding to the instructed speed is output. On the other hand, when the tilt angle signal becomes 0, that is, when the stop command is issued,
The CPU unit 12 calculates the instructed speed as 0, and sets the predetermined time T2.
After the elapse of (see FIGS. 2 and 3), the gate block signal is output, the output of the PWM pulse is stopped, and after a predetermined time T3 (see FIGS. 2 and 3), the relay off signal is output. Immediately after turning on the main switch 1a, the CPU unit 12 outputs a gate block signal.

The relay 9 has a normally closed terminal connected to one terminal of the voltage adjusting section 8 and a normally open terminal connected to the positive electrode of the battery 2. The common terminal is connected to the other terminal of the voltage adjusting unit 8. As a result, when the relay 9 is turned on based on the relay on signal, the common terminal and the normally open terminal are connected, the battery 2 and the voltage adjusting unit 8 are connected, and the relay 9 is turned off based on the relay off signal. The common terminal and the normally closed terminal are connected, and both terminals of the voltage adjusting unit 8 are directly connected. The relay 9 is also turned off when the main switch 1a is turned off.

The drive circuit 14 outputs a gate signal for operating the FETs 4 and 7 based on the PWM pulse,
A gate signal for operating the FETs 5 and 6 is output. In this case, as shown in FIG.
A pulsed gate signal is output at the same time, and a pulsed gate signal is output at the same time. Here, the gate signals are the same signals, and the gate signals are also the same signals. However, the gate signal and the gate signal have opposite phases. In addition,
One cycle C of the gate signal is an extremely short time of about several tens of μs.

In the voltage adjusting section 8, the FETs 4 and 6 are connected in series, and the FETs 5 and 7 are also connected in series.
The row of FETs 4 and 6 and the row of FETs 5 and 7 are connected in parallel, and the connection point of the FETs 4 and 6 and the FET
The motor 3 is connected to the connection points 5 and 7.

Each of the FETs 4 to 7 is turned on and becomes conductive during the high level period of the corresponding gate signal ~ in the figure. In this case, when the relay 9 is turned on and the FETs 4 and 7 are turned on by the gate signal, the terminal a side of the motor 3 is the positive side of the battery 2 and the b terminal side is the battery 2
Is connected to the negative side of. Further, when the FETs 5 and 6 are turned on by the gate signal, the terminal b of the motor 3 is
The side is connected to the positive side of the battery 2, and the side a is connected to the negative side of the battery 2.

Since the a terminal side is connected to the plus side of the battery 2 during the high level period of the gate signal and the b terminal side is connected to the plus side of the battery 2 during the high level period of the gate signal, the motor 3 is connected. The polarity of the applied voltage changes depending on the gate signal. Also, the average value is
It is determined according to the duty ratio, which is the ratio of the width of the high level period of the gate signal. At this time, the direction of the current flowing to the motor 3 cannot change at the same time as the gate signal due to the inductance component of the motor 3, and one cycle period of the gate signal is extremely short for the inertia of rotation of the motor 3. Therefore, the current flowing to the motor 3 depends on the average voltage value applied to the terminals, and its value and direction are determined by the running state of the vehicle. The rotation speed of the motor 3 also depends on the average voltage value.

By the way, when the high level period of the gate signal is long (duty ratio> 50%), the average voltage at the terminal a becomes larger than at the terminal b, the motor 3 rotates in the forward direction, and the electric wheelchair moves forward. To do. When the high level period of the gate signal is long (duty ratio <50%
In the case of), the average voltage at terminal b becomes larger than at a, the motor 3 reverses, and the electric wheelchair moves backward. Then, when both high level periods are the same (when the duty ratio = 50%), the average voltage becomes 0, the motor 3 stops, and the electric wheelchair also stops.

As described above, the rotation speed of the motor 3 is controlled by controlling the gate signal and the pulse width of the gate signal, that is, the duty of the PMW pulse, and the forward / backward switching of the electric wheelchair and the speed control are smoothly performed. Done

As described above, when the tilt angle signal becomes 0 and the CPU section 12 outputs the gate block signal, the drive circuit 14 stops the output of all the gate signals. As a result, all the FETs 4 to 7 are turned off, and the battery 2 does not energize the motor 3.

Further, when the main switch 1a is turned off, the electrical connection between the battery 2 and the controller 11 is released, so that all of the gate signals ~ are stopped and all the FETs 4-7 are turned off. Further, the exciting current from the CPU unit 12 to the relay 9 is stopped and the relay 9 is turned off.

B. Operation of the Embodiment Next, the operation of the present embodiment will be described with reference to FIGS. 2 and 3. 2 is a flowchart showing the operation of the embodiment, and FIG. 3 is a timing chart showing the normal operation of the embodiment. B-1. System Activation First, the occupant turns on the main switch 1a on the operation panel. As a result, the battery 2 and the controller 11 are electrically connected, and the CPU section 12 and the drive circuit 14 are connected.
Is enabled and the system is in the boot state. In this system activation state, the tilt angle signal from the joystick 1b is always input to the CPU section 12, and the CPU section 12 calculates the instructed speed according to the tilt angle signal. And
In step S1, the CPU unit 12 outputs a gate block signal so that the drive circuit 14 does not output the gate signals ~. At this point, the relay 9 is off because the CPU 12 does not output the relay-on signal.

B-2. Running of Electric Wheelchair Next, in step S2, the CPU unit 12 determines whether or not the instructed speed is zero. If the occupant tilts the joystick 1b, the CPU 12 calculates the instructed speed according to the tilt angle, and the instructed speed does not become 0. Therefore, the determination result in step S2 is "YE
S ”, and the process proceeds to step S3. In step S3, it is determined whether or not relay 9 is already turned on.

When the result of the determination in step S3 is "NO", the process proceeds to step S4, in which the CPU section 12 outputs a relay-on signal to turn on the relay 9. This allows
The battery 2 and the voltage adjusting unit 8 are connected, and the voltage adjusting unit 8
Can be operated. Next, the CPU unit 12 waits until the predetermined time T1 elapses, and the CPU unit 12 releases the gate block signal (steps S5 to S6). As a result, the drive circuit 14 becomes ready to supply the gate signal ~ to the voltage adjusting unit 8. Then, the process proceeds to step S7. In addition, when the determination result of step S3 is "YES", it transfers to step S7 immediately.

In step S7, the CPU section 12
The PWM pulse according to the commanded speed is output. As a result, the drive circuit 14 outputs the gate signal and the gate signal as described above, and the FETs 4, 7 and FET
The motors 5 and 6 are alternately turned on, the motor 3 rotates normally or reversely at the instructed speed, and the electric wheelchair runs.

Now, in step S5, the predetermined time T1
By waiting, as shown in FIG. 3, the output of the gate signals ~ is delayed by a predetermined time T1 after the relay 9 is turned on. Immediately after the relay 9 is switched, the terminal portion vibrates and the connection state of the relay 9 is not stable, and the energization of the voltage regulator 8 from the battery 2 becomes unstable, which adversely affects the life of the relay 9. This is because there is a possibility that However, by providing the standby time T1, it is possible to energize after the connection state of the relay 9 becomes stable, and
It is possible to extend the life of the. The waiting time T1 is
It is preferably about several tens of ms.

After that, the process proceeds to step S8, it is determined whether or not the main switch 1a is turned off. If the main switch 1a is not turned off, the process returns to step S2 described above and the traveling control of the electric wheelchair is continued. If the occupant tilts the joystick 1b, step S
The determination result of 2 is "NO", and the determination result of step S3 is "YES" because the relay 9 is already turned on. The process proceeds to step S7, and the output of the PWM pulse according to the instructed speed is output. Done. Then, this process is repeated, and the traveling of the electric wheelchair is continued.

B-3. Stopping Operation by Joystick Further, when the occupant sets the joystick 1b to the neutral position, the CPU section 12 calculates the instructed speed to be 0 in response to this. As a result, the determination result in step S2 becomes "NO", and the process proceeds to step S9. In step S9, it is determined whether relay 9 is turned on. Here, for example, while driving, the joystick 1b
The relay 9 remains on when the switch is set to the neutral position. In such a case, the judgment result is "YES".
Becomes

When the result of the determination in step S9 is "YES", the process stands by until the predetermined time T2 elapses (step S10). During the waiting time T2, as shown in FIG. 3, the pulse width of the gate signal and the pulse width of the gate signal are set to C / 2 during one cycle C of the gate signal. Thus, in the voltage adjusting unit 8, when the pulse widths of the FETs 4, 7 and the FETs 5, 6 are made equal, the rotation of the motor 3 is suppressed, and the electric wheelchair is stopped as shown as the actual speed in FIG. The waiting time T2 is preferably 1 to several seconds.

After that, the CPU section 12 outputs a gate block signal (step S11). As a result, the gate signals ~ are all stopped, the FETs 4-7 are all turned off, and the power supply from the battery 2 to the motor 3 is stopped. Further, the CPU unit 12 stops the calculation of the instructed speed, and
The output of the WM pulse is stopped (step S12).

Thereafter, the CPU section 12 waits until the predetermined time T3 has elapsed, and the CPU section 12 turns off the relay 9 (step S
13-S14). As a result, both terminals of the voltage adjusting unit 8 are directly connected, and via the parasitic diodes of the FETs 4 to 7,
Both terminals of the motor 3 are directly connected.

In step S13, the predetermined time T
By waiting for 3 hours, as shown in FIG. 3, the relay 9 is turned off for a predetermined time T3 after the output of the gate signals ~ is stopped.
Will be delayed only. This is because if the current continues to be supplied just before the relay 9 is turned off, a surge may occur when the relay 9 is turned off, which may adversely affect its life. However, by providing the waiting time T3, the relay 9 can be switched after the power supply is stopped, and the life of the relay 9 can be extended. Standby time T
3 is preferably about several ms.

Now, after the power supply to the motor 3 is stopped,
When a force to rotate the wheels is applied, the motor 3 operates as a generator and generates a voltage between the terminals. At this time, in step S14, since both terminals of the motor 3 are directly connected, a current according to the magnitude of the generated voltage flows through the motor 3. Due to this current, a torque in the direction opposite to the force applied to the wheels is generated on the rotating shaft of the motor 3. Rotation of the motor 3 is suppressed by the torque that repels the force that attempts to rotate the wheel.

That is, when the motor 3 rotates forward and the electric wheelchair tries to move forward, the current generated by the motor 3 tends to flow in the direction of arrow B in FIG. 1, that is, from the FET 6 to the FET 5. This is the direction of the current that causes the motor 3 to rotate in the reverse direction. When the motor 3 rotates in the reverse direction and the electric wheelchair tries to move backward, the current generated by the motor 3 is in the direction of arrow A in FIG.
In other words, it tries to flow from FET7 to FET4. This is the direction of the electric current that normally rotates the motor 3. With such an electric current, the rotation of the motor 3 is forcibly suppressed, and the power generation braking by the motor 3 is applied. Thus, thereafter, the motor 3 itself acts as a parking brake for the wheels.

Then, in step S8, when the occupant turns off the main switch 1a, the electrical connection between the battery 2 and the controller 11 is released, and the system becomes inoperative.

If the main switch 1a is not turned off in step S8, the process proceeds to step S2. If the occupant does not tilt the joystick 1b, the instruction speed calculated by the CPU unit 12 is 0, so the determination result of step S2 is "YES", and the process proceeds to step S9. Since the vehicle is stopped, the determination result in step S9 is "NO", and the relay 9
The OFF state and the gate block signal output state are maintained (step S15), and the process returns to step S8. In this way, the state in which the motor 3 is not energized and the motor 3 works as a parking brake is continued. Even when the occupant does not tilt the joystick 1b after the system is started, the operation of shifting to step S2, step S9, step S15, and step S8 in this order is repeated, and the motor 3 continues to function as a parking brake. To be done.

When the electric wheelchair is to be restarted after the vehicle is once stopped by operating the joystick 1b, the joystick 1b with the main switch 1a kept on.
Again, tilt it back or forth. As a result, step S8, step S2, step S3, step S4 are performed in this order, and the motor 3 is rotated forward or backward.

B-4. Stopping operation by main switch In the present embodiment, while the electric wheelchair is running,
The brake is adapted to operate even when the main switch 1a is turned off. Explaining this, after the traveling operation from step S2 to step S7,
When it is detected in step S8 that the main switch 1a is off, the electrical connection between the battery 2 and the controller 11 is released. In this case, the drive circuit 14 is also in the non-operating state, that is, all of the gate signals ~ are in the same state as the output stop, and the FETs 4-7 are turned off. As a result, the power supply to the motor 3 is stopped.

When the main switch 1a is turned off, the exciting current from the CPU section 12 to the relay 9 is stopped and the relay 9 is turned off. Accordingly, the voltage adjusting unit 8
Are directly connected, and both terminals of the motor 3 are directly connected via the parasitic diodes of the FETs 4 to 7. Even if the drive current of the motor 3 is stopped, the rotating shaft of the motor 3 tries to idle, but by directly connecting both terminals of the motor 3 in this way, the motor 3 acts as a power-generating brake as described above. . As a result, the rotation of the motor 3 is forcibly stopped, and the electric wheelchair stops. Then, thereafter, similarly to the above, the motor 3 itself acts as a parking brake for the wheels.

C. Conclusion As described above, in the present embodiment, when the occupant operates the joystick 1b to set the instructed speed to 0, the CP
The U portion 12 switches the relay 9 to stop energization from the battery 2 to the motor 3 and directly connect both terminals of the motor 3. As a result, the motor 3 is electrically braked and its rotation is suppressed. Therefore, the brake can be applied to the motor 3 only by switching the relay 9, and the control circuit can be made extremely simple.

Further, since both terminals of the motor 3 are directly connected, the motor 3 can be operated even when the electric wheelchair is parked or parked.
Acts as a parking brake. Therefore, it is not necessary to use the electric power for the parking brake when parking or stopping the vehicle, and it is not necessary to separately provide a mechanical parking brake. As a result, it is possible to reduce the electric power cost for parking and stopping and the manufacturing cost for mechanical braking. Further, by eliminating the need for a mechanical brake, the electric wheelchair can be made lighter in weight, and the loss of electric power during traveling can be reduced, which is economical.

Further, in this embodiment, not only is the joystick 1b set to the neutral position, but also the main switch 1
By turning off a, the motor 3 also applies a power-generating brake to prevent its rotation. As described above, since there are two stopping methods, it is convenient in the case of an emergency stop or the like.

In step S5, the predetermined time T1
By turning on the relay 9 by turning on, the FETs 4 to 7 are turned on to start energizing the relay 9, and by waiting for a predetermined time T3 in step S13, the energizing of the relay 9 is turned on. After being stopped, the relay 9 is turned off and both terminals of the motor 3 are directly connected. As a result, when the contact state after switching the relay 9 is unstable, the energization is prevented, and the life of the relay 9 can be extended. This is particularly advantageous when the terminal portion is likely to vibrate immediately after switching the relay 9.

Further, in step S10, the predetermined time T
2 stand by, and during this period, the pulse width of the gate signal is made equal to the pulse width of the gate signal, so that the motor 3
The average voltage to is 0. Also by this, the electric wheelchair is decelerated or stopped, and it is surely stopped when the motor 3 acts as a dynamic brake.

Further, in the present embodiment, the polarity of the voltage applied from the battery 2 to the motor 3 via the relay 9 is instantly inverted by the voltage adjusting section 8 within a predetermined cycle, whereby the rotation direction and rotation of the motor 3 are rotated. Adjusting speed. Then, by adjusting the pulse width of the PWM pulse voltage output by the CPU unit 12, the conduction of the FETs 4 to 7 forming the voltage adjusting unit 8 is controlled, and the forward / backward switching of the electric wheelchair is smoothly performed. Therefore, it is economical because it is not necessary to separately provide a change-over switch for changing the energization direction to the motor 3 by the operation of the occupant. Further, since the voltage control section 8 performs all traveling control such as speed control, braking, and switching of traveling direction of the electric wheelchair, the control circuit can be made extremely simple.

D. Modifications The present invention is not limited to the above-described embodiment, and various modifications can be made as follows. One or both of the main switch for the caregiver and the joystick may be provided so that the caregiver can operate the electric wheelchair. In this case, the means for stopping the electric wheelchair is increased, which is convenient in the case of an emergency stop or the like. When a tilt sensor is provided on the body of an electric wheelchair and the vehicle travels on a forward slope, the pulse width of the gate signal is made longer to increase the forward drive force than in the above-described embodiment, and the vehicle travels on a forward slope. At times, the pulse width of the gate signal may be made longer than in the above-described embodiment to reduce the forward drive force. In this case, if the vehicle is traveling on a flat road during the waiting time T2 when the vehicle is stopped, as described above,
Both the pulse width of the gate signal and the pulse width of the gate signal may be set to C / 2. The pulse width of the gate signal may be made slightly longer than C / 2 when climbing forward, and the width of the gate signal may be shortened when falling forward. The pulse width may be set slightly longer than C / 2 so that a larger amount of drive current flows in the direction against gravity. It is possible to use not only the relay 9 but also other means as the changeover switch means.

[0050]

As described above, according to the invention described in claim 1, when the stop command is issued from the speed control operator or the main switch is turned off,
Both terminals of the motor are directly connected, and with this alone, the motor can be braked dynamically. Therefore, the control circuit can have an extremely simple structure. Further, by directly connecting both terminals of the motor, the motor functions as a parking brake even when the electric wheelchair is parked or stopped. Therefore, it is not necessary to use the electric power for the parking brake when parking or stopping the vehicle, and it is not necessary to separately provide a mechanical parking brake. As a result, it is possible to reduce the electric power cost for parking and stopping and the manufacturing cost for mechanical braking. Further, by eliminating the need for mechanical brakes, it is possible to reduce the weight of the electric wheelchair and reduce the loss of electric power during traveling, which is economical. Further, when a stop command is issued from the speed control operator, or when the main switch is turned off, the motor is electrically braked and rotation of the motor is suppressed. As described above, since there are two stopping methods, it is convenient in the case of an emergency stop or the like. Furthermore, the contact state after the changeover switch means is changed
When it is unstable, the energizing of the changeover switch means is prevented.
It is possible to extend the life of the changeover switch means.
It This is because the terminal part which is the contact immediately after switching does not vibrate.
Use a relay that is easy to raise as changeover switch means
The case is particularly advantageous.

[0051] In the invention described in 請 Motomeko 2, after stabilizing the contact state of the switch means, it can be energized to this, it is possible to increase the life of the switch means. This is particularly advantageous, for example, when a relay in which a terminal portion which is a contact immediately after switching is apt to vibrate is used as the changeover switch means.

According to the third aspect of the present invention, the switching unit facilitates switching between forward and backward movements of the electric wheelchair and speed control. Therefore, it is economical because it is not necessary to separately provide a changeover switch for changing the energizing direction to the motor by the operation of the occupant. In addition, the control device can have an extremely simple structure.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit of an electric wheelchair control device according to an embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of the same embodiment.

FIG. 3 is a timing chart showing a normal operation of the same embodiment.

[Explanation of symbols]

1a Main switch, 1b Joystick (speed control operator), 2 batteries, 3 DC motor, 4-7 FET (switching element), 8 voltage regulator (switching unit), 9 relays (changeover switch means), 11 controller, 12 CPU part, 13 Control power supply unit, 14 Drive circuit

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) A61G 5/04 B60L ^7/ 00-7/28 H02P 3/12

Claims (3)

(57) [Claims] 1. An electric wheelchair control device for controlling the traveling of a wheel of a wheelchair by a motor, wherein a speed control operator for outputting a traveling command and a stop command according to an operation of an operator, and the traveling command are provided. A controller for energizing and controlling the electric power of the battery to the motor, a main switch for turning on / off the electric power supply to the controller of the battery, one terminal connected to one end side of the motor, and the other terminal of the battery It is connected to one electrode of, on a change-over switch means for the common terminal is connected to the other end of the motor, provided on the feeding path of the motor, the energization amount /
Comprising a switching unit controlled by off operation, said controller, when said travel command is issued, Rutotomoni to connect the common terminal and the other terminal of the changeover switch unit, the traveling
The on / off time of the switching unit is controlled according to the command.
On the other hand, when the stop command is issued or when the main switch is turned off, the common terminal of the changeover switch means is connected to one terminal and the switch switch is connected .
The switch section is turned off after a lapse of a predetermined time.
A control device for an electric wheelchair, characterized in that one of the common terminals is connected to the other terminal . 2. The controller starts ON / OFF time control of the switching unit after the traveling command is issued to connect the common terminal and the other terminal of the changeover switch means. The control device for an electric wheelchair according to Item 1 . Wherein the switching arrangement, H-bridge-connected plurality of electric wheelchair control system according to claim 1 or 2 wherein, characterized in that it is constituted by a switching element.