JPS6292705A - Controller for motor car - Google Patents

Abstract

PURPOSE:To obtain excellent travelling performance even on the travelling of both tracks of a straight line and a curve by using a position regulator as a P regulator on travelling on the straight line and employing the position regulator as a PI regulator on travelling on the curve. CONSTITUTION:A position regulator 9 outputs a deviation signal DELTAN* between a position detecting signal x0 and a position set value x*. A speed regulator 6 outputs a current set point I* corresponding to a deviation between a signal acquired by adding the deviation signal DELTAN* and a speed set point N*0 and a speed detecting value. A current regulator 5 controls a power converter 4 in response to a deviation between the current set point I* and a current detecting value. A switch 95 is short-circuited and the position regulator 9 is used as a P regulator on travelling on a straight line, and the switch 95 is opened and the position regulator 9 is employed as a PI regulator on travelling on a curve.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a control device for an electric 1JJJ vehicle that runs unmanned on a predetermined track.

[Conventional technology]

Automation in various factories has been remarkable in recent years, and so-called unmanned electric vehicles, which do not require human intervention, are increasingly being used to transport goods.

FIG. 2 is a schematic diagram showing such an electric vehicle, and FIG. 3 is a block diagram showing a specific example of a position detector attached to the electric vehicle.

That is, as shown in FIG. 2, for example, this type of electric vehicle 20 includes a pair of left and right wheels 21a and 21b driven by electric motors 1a+1b, and travels on a predetermined track 22. A guide wire (not shown) is laid on the track 22, and an alternating current is passed through it. The position detector 10 thereby detects the displacement X of the vehicle 20 from the track 22. Therefore, by providing a speed control system for each of the electric motors 1a and 1b and also providing a position adjuster for adjusting the displacement can be done.

As shown in FIG. 3, the position detector 10 is composed of a pair of left and right induction coils 101, 102, rectifiers 103 and 104, a subtractor 105, a filter 106, etc., and is proportional to the magnitude of the alternating current magnetic field generated from the induction wire. The alternating current voltage is taken out through induction coils 101 and 102, and after rectifying these outputs by rectifiers 103 and 104, the difference between them is calculated by a subtracter 105, 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 taking this control stability into consideration, and the radius of curvature of the track on which the electric vehicle could travel was also determined accordingly. but,
In recent years, when an electric vehicle that can travel on curves with a smaller radius of curvature than before is required in order to make effective use of space, there are cases in which such a P adjuster cannot handle the situation.

Therefore, the applicant changed the position adjuster to a proportional-integral (P) adjuster, so that even with the same proportional sensitivity as the conventional one, a larger regulator output than the conventional one could be obtained by utilizing the integral term function of the PI adjuster. proposed a control device that could run on a curved trajectory with a smaller radius than before (patent application filed in 1983).
0-128307).

However, when the position adjuster is used as a PI adjuster and a P adjuster, and the running performance on a straight line is actually tested and compared, it is found that the running stability is better when the position adjuster is used as a PI adjuster than when it is used as a P adjuster. was found to decrease slightly.

Therefore, an object of the present invention is to provide a control device for an electric vehicle that can improve running performance both when traveling in a straight line and when traveling on nine curves.

[Means for solving problems]

The position adjuster is configured to function as a P adjuster when traveling in a straight line and as a PI adjuster when traveling on a curve.

[Effect]

By configuring the position adjuster as described above, running stability and safety can be maintained on a straight track, and sufficient curve running performance can be ensured on a curved track.

〔Example〕

FIG. 1 is a block diagram showing an embodiment of the invention. In addition, in the figure, each number has a suffix a or b attached to it, but this is to distinguish between the control systems of the left and right wheels, and their functions are completely the same, so the following explanation will be given. Let's omit the suffix unless it's particularly necessary.

In FIG. 1, 2 is a speed detector for detecting the speed of the motor, and 6 is a current detector for detecting the motor current. The current detected by the current detector 3 is led to a current regulator (ACR) 5, where it is compared and adjusted with a current target value I. The calculation result is led to the power converter 4, and the converter 4 changes the converter output in order to cause a current corresponding to the current target value I to flow through the motor. 6 is the speed regulator (ASR
), and the speed target value N obtained as the output of the adder 7 is
The above current target value Bi is created by comparing and adjusting the detected speed value given as the output of the speed detector 2. 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 X 1 in the position adjuster 9, and the result of this calculation is directly led to the adder 7a and to the adder 7b via the inverting amplifier 8. In the adder 7, the position adjuster 9 guided in this way
Using the output and the speed set value No as input, a speed target value N''(Na'', Nb) is formed.

By the way, the position adjuster 9 used here includes, for example, an operational amplifier 91 and a resistor 92 as shown in FIG. 1A.
, 93, a capacitor 94, and a switch 95.

This switch 95 is short-circuited when the vehicle is running in a straight line, so that the position adjuster 9 becomes a P adjuster, and is opened when the vehicle is running on a curve and becomes a PI adjuster. The signal necessary for switching the switch 95 can be easily obtained by a detector having the same configuration as the position detector 10, a proximity switch, or the like. When such an adjuster is used as the position adjuster shown in FIG. 1, since the position adjuster acts as a P adjuster during straight running, more stable control is possible than when using a PI adjuster. Furthermore, since the position adjuster acts as a PI adjuster when traveling on a curve, sufficient traveling performance can be obtained when traveling on a curve.

When moving from curved driving to straight driving, the position adjuster is switched from the PI adjuster to the P adjuster.
When used as an I regulator, if the ratio of the magnitude of the integral term of the regulator to the magnitude of the regulator output is large, the change in the regulator output when switching from the PI regulator to the P regulator will be large, and the switching At times, the running of electric vehicles may become unstable.

However, if you switch to the P adjuster after completely shifting to a straight trajectory, the integral term will be small, so there will be no instability at the time of switching. On the other hand, P from the P regulator
When switching to the I regulator, the magnitude of the integral term of the P regulator changes slowly from O over a constant integration time, so
There is no instability during switching.

Further, when the electric vehicle is stopped, the switch 95 is shorted. In this way, the voltage of the integral term of the regulator is 0
Therefore, even if the switch is opened at the start of operation, the regulator will only output a value determined by the proportional sensitivity of the regulator. Therefore, the electric vehicle can run stably from the time it is started.

〔Effect of the invention〕

According to this invention, the position adjuster is a P adjuster when traveling in a straight line and a PI adjuster when traveling on a curve.
The advantage is that good running performance can be obtained when running on any curved track.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 1A is a circuit diagram showing a specific example of a position adjuster, Fig. 2 is a schematic diagram showing a general electric vehicle, and Fig. 5 is a position detector. It is a block diagram showing a specific example. Code explanation 1a, 1b...Electric motor, 2a, 2b...
・Speed detector, 3a, 3b...Current detector, 4
a + 4 b...Power converter, 5a,
5b =-'IL flow regulator (Act"t), 6a+6b
... Speed regulator (ASR), 7a, 7b...
...Adder, 8...Inverting amplifier, 9...
...Position adjuster (PI adjuster), 10...Position detector, 20...Vehicle, 21a, 21b...
...Wheel, 22...Track, 91...
Operational amplifier (op-amp), 92.93...Resistor, 94...Capacitor, 95...Switch, 1CN. 102... Induction coil, 103, 104...
... Rectifier, 105 ... Subtractor, 106 ...
····filter. 2nd figure 27a character figure 3

Claims (1)

[Claims] A speed control system that individually controls the speed of a pair of wheels attached to the left and right sides of an electric vehicle that runs unmanned on a predetermined trajectory, and the electric vehicle does not deviate from the trajectory. A position adjuster is provided to adjust the position as shown in FIG. In an electric vehicle control device that controls an electric vehicle based on each speed target value,
A control device for an electric vehicle, characterized in that the position adjuster is configured to function as a proportional adjuster when traveling on a straight track and as a proportional/integral adjuster when traveling on a curved track.