JPS61147707A - Controller for electric automobile - Google Patents

Abstract

PURPOSE:To smoothen a starting characteristic by restarting by reducing the gain of a current control amplifier when a slip of a drive wheel is detected. CONSTITUTION:When an angular acceleration domega/dt differentiated from an angle velocity detected by a rotation detector 6 increases larger than an abnor mal angle acceleration value K, a comparator 10 sets a flip-flop 11. Thus, an FET2 is turned ON, a capacitor C1 is discharged, and the output of a propor tional integrator 13 becomes zero. If the velocity becomes zero, the flip-flop 11 is reset, and a flip-flop 12 is set. Thus, the FET1 is conducted to reduce the gain of the integrator 13, and a vehicle is automatically restarted in this state. If the velocity omega becomes larger than the set value omega0, the flip-flop 12 is reset, the FET1 is again conducted, and the gain of the integrator 13 is returned to the original.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an improvement of an electric vehicle control device with smooth starting characteristics.

[Technical background of the invention and its problems]

A configuration diagram of a conventional electric vehicle control device is shown in FIG.

Xi control control Ankoko, current reference signal IR1 output from accelerator/! ! F and the current of the motor are detected by the current detector p<, as the current feedback signal IFB, and each is input through the resistor R/1.2, the deviation is proportionally integrated, and the result is used to drive the motor. Outputting to device 3.

The proportional integrator /J is composed of a capacitor C and a resistor R4L' which feed back and integrate the output of the current control amplifier, and the rotation detector 6 which detects the speed of the electric motor is connected to the electric motor! The detection output is fed back to the motor drive device 3 via a coupling g.

This electric motor drive device J is an electric motor! If it is a DC machine, it could be a thyristor Leonard device, and if it is an AC machine, it could be an inverter device, but since we are only focusing on the circuit around the current control amplifier, we will not discuss it here. .

If the driver depresses the accelerator too much during starting, a large current reference IREF will be generated, giving excessive torque to the electric motor and causing damage to the gap between the tires and the road, especially if the road is muddy or icy. The frictional force cannot overcome the excessive torque, causing the tires to spin, making it impossible to start, or in such cases, even if the wheel is released slightly from the accelerator to stop the wheel from spinning, the vehicle may suddenly start. There was a problem.

[Purpose of the invention]

The present invention aims to provide an electric vehicle control device that overcomes the drawbacks of conventional devices, improves the starting characteristics of electric vehicles to smooth ones, and prevents slipping, sudden starts, etc.
That purpose.

[Summary of the invention]

The present invention provides a current control amplifier that immediately adjusts the output of the motor drive device when an electric vehicle starts idling, a capacitor C/ that creates its feedback circuit (for integration), and a resistor R3 connected in series for gain adjustment. The charge stored in the capacitor CI of the proportional integrator/3 consisting of and Rda is discharged, and the electric motor! , then reduce the gain of the proportional integrator 13,
By slowing down the current control response, even if the accelerator pedal is suddenly pressed, the rise of the electric motor's torque will be smooth, preventing slippage and sudden start, and after a smooth start is obtained, the proportional integrator This is an electric vehicle control device comprising means for returning the gain of /J to its original value and increasing the current control response to a normal value again.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows the circuit configuration of this embodiment.

The same reference numerals represent the same or corresponding parts in all drawings.

The rotation detector 6 of the electric motor j is connected to a dffl/dt detection circuit 7 which feeds back the motor speed to the motor control device 3 and which detects the angular velocity ω of the motor shaft and further detects the same angular acceleration.

When the wheels of an electric car spin, it's the electric motor! is accelerated under no-load condition, so the angular acceleration of the motor shaft d6v′d
t shows a considerably larger value than during normal acceleration under load.

Therefore, the angular velocity ω detected by the rotation detector B is d
In the ω/dt detection circuit 7, the angular acceleration d4t is obtained by dividing the value by one aircraft at time t.

Next, the comparator 10 calculates the preset abnormal angular acceleration value.
Compare at.

At this time, if the angular acceleration dφt is large due to an abnormal value, the comparator 10 outputs "P" to the input S of the 7 lip flop//, so the flip 70// outputs "/" to the output Q.

As a result, FET:1 turns ON, and capacitor C
The charge stored in I is discharged through resistor R5,
The output of the proportional integrator /3 approaches zero, becomes sufficiently small, and when the torque of the electric motor meets the frictional force of the mechanical system, the rotation of the electric motor j stops.

To stop the electric motor 5, the angular velocity ω detected by the rotation detector B is compared with the value O by the comparator D, and if ω=O,
The comparator D outputs 11", sets the output Q of the flip-flop 70/l to "O#", turns off the FET/co, and at the same time outputs °l" to the input S of the flip-flop/20.

As a result, QK@/" is output to the flip-flop and FET/ is turned on. As a result, the resistor R3 of the proportional integrator 13 is short-circuited, and the gain of the proportional integrator 13 becomes the original (RJ + R da). /R/ changes to Rs/R/,
Gain decreases.

In such a state, even if you step on the accelerator l suddenly, the rise of the current will be gradual, and no slipping or sudden start will occur.
A smooth start can be obtained.

After a smooth start, the angle ω of the motor shaft is set to the value ω previously set by the comparator/4'. and the angular velocity ω
When it becomes larger, the comparator /f outputs "/" and resets the flip-flop /co. Therefore, FET/
becomes the OFF state again, and the gain of the proportional integrator /,3 returns to the original (R,?+In)/R/.

The reason why the gain is switched in this way is that when actually driving a car, the current response needs to be fast in order to avoid danger or overtake.

The operation of the electric vehicle control circuit according to this embodiment is expressed in a time chart, which is shown in FIG.

As shown in FIG. 2(a), the angular velocity ω of the motor shaft increases rapidly when idling occurs.

On the other hand, when the angular acceleration dm/at reaches the abnormal value K at time t, FE is
While T2 turns ON, electric motor j goes to a stop.

When it stops completely, FETJ turns OFF and at the same time FE
T/ is ONt, and the electric motor starts at time t2 more slowly than before.
The vehicle accelerates from t4 to t4, and at time t4, the vehicle shifts to constant speed driving.

On the way, set value ω. When passing through, FET/ is turned off and the gain of the proportional integrator 13 returns to its original value, as shown in FIG. 1(d).

Other embodiments of the present invention include the following means.

In FIG. 1, the resistor Rt is grounded via the FETJ, but it may be connected to a negative potential of a control power source (not shown) instead of the ground.

This is because the capacitor C discharges faster, so the output of the current control amplifier also goes to zero faster, and as a result, the time it takes for the motor to stop [from t1 to t2 in Figure 2 (a) It gets faster.

FETJ is the angular velocity of the electric motor, O at the moment ω becomes zero.
Since it is in the FF state, the output of the current control amplifier will never become negative.

〔Effect of the invention〕

Thus, according to the present invention, even if the driver depresses the accelerator too hard and idling occurs, it is immediately detected, and the control device not only automatically prevents the idling, but also prevents the driver from pressing the accelerator once. It is possible to start smoothly even if the pedal is pressed down without having to return it.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a circuit configuration in an embodiment of the present invention, FIG. 1 is a time chart showing temporal state transitions of each part in a control device, and FIG. 3 is a circuit configuration diagram of a conventional device. l...Accelerator, Co...Current control amplifier, 3...
Motor drive device, G... Current detector, S... Electric motor, 6... Rotation detector, 7... dffl/dt (angular acceleration) detection circuit, t... Coupling, ? , 10
．． /'f... Comparator, //, /λ... Flip-flop, 13... Proportional integrator.

Claims (1)

[Scope of Claims] 1. In a control device for an electric vehicle using an electric motor as a drive source, the circuit includes: a circuit that detects idling of the drive wheels at the time of starting; and an output of a current control amplifier that adjusts the output of the electric motor drive device after the idling is detected. An electric vehicle control comprising: a circuit provided with a means for once narrowing down the gain in a negative direction, a means for lowering the gain of a current control amplifier when the rotation of the drive shaft stops, and a means for switching the gain to the normal gain again after restarting. Device.