JPS61288705A - Controller for motor-driven vehicle - Google Patents

Abstract

PURPOSE:To obtain a controller for a motor-driven vehicle having excellent traveling performance curve by using a position regulator necessary to control the vehicle not to displace from an orbit as a proportional integrating regulator. CONSTITUTION:A speed regulator 9 compares the output of a position detector 10 with a set position value X*, regulates it, and applies the calculated result directly to an adder 7a and through an inverting amplifier 8 to an adder 7b. The adder 7 inputs the output of the regulator 9 and the set speed value N*0, and forms a target speed value N*(N*a,N*b). A proportional integrating regulator is used as the regulator 9. Thus, the speed difference between a right wheel and a left wheel can be increased, and a vehicle can travel along a curved orbit having smaller radius of curvature than the conventional one.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The invention relates to a control device for an electric vehicle that runs unmanned on a predetermined trajectory.

[Conventional technology]

Automation in various factories has been remarkable in recent years, and so-called unmanned electric vehicles, which do not require human labor to handle and transport cargo, are increasingly being used. FIG. 3 is a sectional view showing an outline of such an electric vehicle, and FIG. 4 is a block diagram showing a specific example of a position detector.

That is, this type of electric vehicle 20 is, for example, as shown in FIG.
, a pair of left and right wheels 21a s 2 lb driven by electric motors 1a and 1b, and a predetermined trajectory 22.
run on top. A guide wire (not shown) is laid on the track 22, and an alternating current is passed between and. The position detector 10 is
Thereby, the displacement X of the vehicle 20 from the track 22 is detected. Therefore, by providing a speed control system for each electric motor 1a+1b and also providing a position adjuster for adjusting the displacement X, it is possible to make the vehicle run along a predetermined trajectory. .

The position detector 10 is configured as shown in FIG. 4 (a pair of left and right induction coils 101 and 102, a rectifier 103 and
Consisting of a subtracter 105 and a filter 106, the current voltage proportional to the magnitude of the alternating magnetic field generated from the induction wire is taken out via induction coils 101 and 102, and the outputs of these are rectified by rectifiers 103 and 104, respectively. did.

After that, the subtracter 105 calculates the difference between them, and the filter 10
6 to obtain the position detection amount.

Note that such a position detector is publicly known.

[Problem that the invention seeks to solve]

By the way, in the past, P (proportional) adjusters were exclusively used as position adjusters in such devices;
There were the following problems. In other words, if the trajectory is a curve, a speed deviation command ΔN sufficient for the electric vehicle to curve around the curve must be given to the left and right speed control systems, but the P adjuster must give a value proportional to the input deviation. When traveling on a trajectory with a small radius of curvature,
The proportional sensitivity of the regulator must be set to a large value. However, if the proportional sensitivity is increased unnecessarily, the control system may become unstable, so there is naturally an upper limit to the proportional sensitivity that can be selected. Therefore, in the past, the proportional sensitivity was selected with this control stability in mind, and the radius of curvature of the track on which the electric vehicle could travel was also determined accordingly. but,
In recent years, when electric vehicles that can travel on curves with a smaller radius of curvature than conventional ones are required in order to make effective use of space, there will be cases where this more rigid P adjuster cannot handle the situation.

Therefore, an object of the present invention is to provide a control device for an electric vehicle that has excellent curved running performance.

[Means for solving problems]

In a travel control device for an electric vehicle that travels on a predetermined trajectory by controlling the speeds of two left and right wheels,
The position adjuster required to control the electric vehicle so that it does not deviate from the track is a PI (relative integral) adjuster.

[Effect]

By doing the above, even with the same proportional sensitivity as before, P
By utilizing the function of the integral term by the I regulator, a larger regulator output than before can be obtained, and it is possible to travel on a curved trajectory with a smaller radius than before.

〔Example〕

FIG. 1 is a block diagram showing an embodiment of the invention. In addition, in the same figure, each number has a suffix a or b attached to it, but this is to distinguish between the left and right wheel control systems, and their functions are completely the same, so the following explanation will not use them. Suffixes shall be omitted unless particularly necessary.

In FIG. 1, 2 is a speed detector for detecting the speed of the motor, and 3 is a current detector for detecting the motor current. The current detected by the current detector 3 is led to the current regulator (ACR) 5, where it is compared and adjusted with a current target value. The calculation result is led to the power converter 4, and the converter 4 changes the converter output so that a current corresponding to the current target value flows through the motor. 6 is the speed regulator (ASR
), and the speed target value N obtained as the output of the adder 7 is
By comparing and adjusting the detected speed value given as the output of the speed detector 2, the above-mentioned current target value ■'' is created. 8 is an inverting amplifier, 9 is a position adjuster, and 10 is a position detector.

The output of the position detector 10 is compared and adjusted with the position setting value x1 in the position adjuster 9, and this calculation result is sent to the adder 7a.
The signal is directly guided to the adder 7b via the inverting amplifier 8. The adder 7 inputs the thus derived output of the position adjuster 9 and the speed setting value No. to form a speed target value N CNB *Nb ).

As the position adjuster 9 used for the toro and to, for example, a PI adjuster consisting of an operational amplifier 91, resistors 92, 93, a capacitor 94, and a switch 95 as shown in FIG. 2A is used.

This switch 95 is opened when the electric vehicle is operated,
Functions as a proportional integrator. Therefore, in this state, a, the input X of the PII 14 node. Even when is small, the output ΔN can be larger by the integral term than when the same input is applied to a P adjuster with the same proportional sensitivity.

Therefore, the speed difference between the two left and right wheels is Na - Nb (=2Δ
b) can be made larger than before, which makes it possible to travel on curves with smaller edge radii than before.

On the other hand, when the engine is stopped, the switch 95 is closed and the output of the regulator is held at zero. In this state, the voltage across the capacitor tends to zero, so that the output of the regulator at the moment the switch 95 is opened during operation has almost no effect from the integral term. Therefore, an unstable state such as an unintended spin turn does not occur in the electric vehicle at the time of starting, and therefore stable control can be performed from the time of starting.

FIG. 2B shows another embodiment of the PI regulator used in the present invention.

This is because the mounting position of the switch 95 is only slightly different from that shown in FIG. 2A, and the operating method is the same as that shown in FIG. 2A, in which the switch 95 is short-circuited when the engine is stopped and opened during operation. Since they are functionally the same, the same driving performance as in the previous embodiment can be obtained in this case as well.

〔Effect of the invention〕

According to this invention, since the position adjuster is a PI clause, even if the proportional sensitivity of the adjuster is the same as the conventional one, a large adjuster output can be obtained due to the effect of the integral term of the adjuster. Since it is possible to increase the speed difference between the left and right wheels, the advantage is that the vehicle can travel on a curved track with a smaller radius of curvature than before.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIGS. 2A and 2B are configuration diagrams showing a specific example of a PI controller, FIG. 3 is a sectional view showing an outline of a general electric vehicle, and FIG. FIG. 4 is a block diagram showing a specific example of the position detector. Code explanation 1a, 1b...Electric motor, 2a, 2b...
・Speed detector, 5a*3b...Current detector, 4
a, 4b...Four gravity converter, 5ae 5b...
Current regulator (ACR), 6a, 6b... Speed regulator (ASR), 7a, 7b-... Adder, 8.
...Inverting amplifier, 9.Tune/position adjuster (PI controller), 10.....Position detector, 2o.Tune/vehicle.
21a, 21b... Wheel, 22... Track, 91... Operational amplifier (op-amp), 92
,93...Resistance, 94・Bending・Capacitor, 95
... Song switch, ICN, 102... Induction coil, 103, 104... Rectifier, 101 song/subtractor, 1o6... Song filter. Agent Patent Attorney Akio Namiki Agent Patent Attorney Kiyoshi Matsuzaki Figure 2A Figure 311! ! 1 210 wheel diagram 4

Claims (1)

[Claims] A speed control system that individually controls the speed of wheels attached to the left and right sides of an electric vehicle that runs unmanned on a predetermined trajectory, and a speed control system that adjusts the position of the electric vehicle so that it does not deviate from the trajectory. and a position adjuster for controlling the speed, and the speed target value of each speed control system is formed by adding the output of the position adjuster to one system and subtracting it to the other system with respect to a common speed setting value. A control device for an electric vehicle that controls traveling of an electric vehicle based on each speed target value, characterized in that the position adjuster is composed of at least a proportional element and a capacitor, and acts as a proportional-integral element during control. A control device for electric vehicles.