JP3114342B2 - Travel control device for electric vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling control device for an electric vehicle such as an electric wheelchair using an electric motor.

[0002]

2. Description of the Related Art In an electric vehicle, the running speed is controlled by the output ratio of a driving pulse of a power supply to a wheel driving motor and a braking pulse (the number of driving pulses in one cycle is called a duty, and all driving pulses There is a traveling control method that is performed by changing the ratio of the duty ratio to the duty ratio. When the vehicle is decelerated and stopped by this traveling control method, the duty is gradually reduced, and finally the duty is stopped at zero, that is, only the braking pulse, so that a sudden braking action is prevented. Further, since it is difficult to completely stop the vehicle body only by the output of the braking pulse, the duty is set to zero and the traveling speed becomes extremely low, and then the electromagnetic brake is actuated to completely stop.

[0003]

In the above-mentioned traveling control method, there is no problem in traveling on flat ground,
If it falls, even if the duty is reduced to zero,
Ri not so much reduced speed by the own weight, so the sudden braking when the action of the electromagnetic brake is a risk that stop shock tipping greatly at this point. SUMMARY OF THE INVENTION It is an object of the present invention to provide a drive control device for an electric vehicle that prevents a sudden brake stop even when the vehicle descends a steep slope.

[0004]

SUMMARY OF THE INVENTION In an electric vehicle in which the rotational speed of a wheel driving motor M is controlled by changing the duty D of a driving pulse, detecting means 14 and 15 for detecting a traveling direction and a speed V.
And speed determining means 10 and driving direction switching means 20 are provided.
If the traveling speed V is less than the extremely low stopping speed Vs or the vehicle is traveling in the reverse direction under the condition that the duty D is zero when the braking is stopped, the electromagnetic brake 24 is operated and stopped if the traveling speed V is equal to or higher than the stopping speed Vs. The reverse brake power is applied to the motor M by operating the means 20, and the electromagnetic brake 24 is operated after the traveling speed V is reduced to less than the stop speed Vs.

[0005]

During normal traveling, the vehicle travels while controlling the rotation speed of the motor M by determining the duty D so that the vehicle travels at the traveling speed V according to the operation of the speed setting device.
When the setting of the speed setting unit is stopped, the duty D is gradually reduced, the traveling speed V is reduced, and when the duty D becomes zero, the traveling speed V becomes zero, and the electromagnetic brake 24 is operated to maintain the stopped state. Complete stop. During this stop operation, if the traveling speed V is higher than the extremely low stop speed Vs even though the duty D has become zero due to reasons such as being down a slope, the electromagnetic brake 24
Drive direction switching means 20 so as to provide reverse drive braking having a larger braking force than regenerative braking or power generation braking without operating the
Since the driving direction of the electric power supplied to the motor M is switched to apply the reverse driving electric power to the motor M for braking, and the traveling speed V becomes smaller than the stop speed Vs, the electromagnetic brake 24 is actuated. Also, a smooth stopping state is achieved, and the riding comfort is improved.

[0006]

Next, embodiments of the present invention will be described. FIG.
FIG. 3 is a block diagram illustrating a connection state between a signal input unit and a control unit. First, an ON / OFF signal of the power switch 11 is input to the central processing unit (CPU) 10, and the output voltage of the variable resistor, which is rotationally adjusted by the accelerator lever 1, is A / A.
D-converted and input, and high / medium / low speed running speed selection is input by the speed change switch 12, and signals from various sensors 13 such as a collision detection sensor, a turning angle sensor and an outside temperature sensor are input. A rotation sensor 14 for detecting the number of rotations of the motor M
The rotation speed and the rotation direction are input through the rotation detection circuit 15.

A power source is a battery 16, which supplies power to the CPU 10 through a CPU power supply circuit 17, inputs a voltage into the CPU 10 through a battery voltage detection circuit 18, performs arithmetic processing, and reduces the charge amount of the battery to five stations. This is indicated on the battery meter 23 composed of an LED. The battery 16 includes a main relay 19 and a forward / reverse switching circuit 2.
0, motor power braking circuit 21, motor drive circuit 22, and motor M to supply power.

[0008] The CPU 10 outputs a drive command to the main relay 19, outputs a braking pulse to the motor power generation braking circuit 21, and outputs a driving pulse to the motor driving circuit 22. The forward / reverse switching circuit 20 is supplied to the CPU 10 by the rotation direction of the accelerator lever 1 or another control signal.
Outputs a forward or reverse switching command. The electromagnetic brake 24 functions as a brake when the power is off,
The brake is released when the power is turned on, and the brake is activated when decelerating and stopping, and when the vehicle is stopped.

Next, the operation state will be described. When the accelerator lever 1 is rotated, the rotation holding angle α is changed by the CPU 1.
When input to 0, the running speed V is calculated, and after turning on the main relay 19, a driving pulse is output to the motor driving circuit 22 and a braking pulse is output to the motor power generation braking circuit 21 so as not to become too fast. Specifically, one cycle is divided into 250 sections, and a drive pulse and a braking pulse are arranged between them. The duty D indicates the number of drive pulses. This is a state in which the motor drive circuit 22 is constituted by pulses and the motor drive circuit 22 is kept energized, and a duty D of zero is a state in which the brake pulse is constituted by one cycle and the motor power generation brake circuit 21 is kept energized. Therefore, if the duty D is large, the vehicle runs at a high speed, and if the duty D is small, the vehicle runs at a low speed.

When the accelerator lever 1 is returned to the stop position, as shown in the flowchart of FIG. 1, the duty D is gradually reduced so as not to cause sudden braking.
If the running speed V is less than the stop speed Vs of 0.1 km / h or reverse running, the electromagnetic brake 24 is actuated and stopped immediately. Running speed V even when duty D becomes zero
If the stop speed Vs is equal to or higher than 0.1 km / h, the deceleration is not sufficient.
After the power supply direction is reversed so that the motor rotates in the reverse direction, the duty D is increased and the traveling speed V becomes 0.1 km of the stop speed Vs.
/ H or less, the electromagnetic brake 24 is actuated and stopped.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a control operation.

FIG. 2 is a block diagram of control.

[Explanation of symbols]

 Reference Signs List 10 speed determination means 14 traveling speed detection means 20 drive direction switching means 24 electromagnetic brake D duty M motor V traveling speed Vs stop speed

Claims (1)

(57) [Claims] 1. An electric vehicle in which the rotation speed of a wheel driving motor (M) is controlled by changing a duty (D) output of a driving pulse, a driving direction and a speed (V) detecting means (1).
4) and (15), a speed judging means (10) and a driving direction switching means (20) are provided.
Is zero, the traveling speed (V) is extremely low and the stop speed (V
s) If the traveling is less than or in the reverse direction, the electromagnetic brake 24 is actuated to stop. If the traveling speed (V) is equal to or higher than the stop speed (Vs), the drive direction switching means (20) is activated to reverse the motor (M). A drive control device for an electric vehicle configured to apply drive power to reduce a travel speed (V) to a value less than a stop speed (Vs) and then to operate and stop an electromagnetic brake (24).