JP3175353B2 - Control system switching control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching control device for switching a control system without giving a switching shock to a control target in a control system having a plurality of control systems.

[0002]

2. Description of the Related Art Various test devices such as chassis dynamometers and engine test devices for simulated driving tests of automobiles and unit tests of engines require switching between speed control, torque control, and intake pressure control during operation. become.

[0003] In addition, a control device having a plurality of control systems is often switched for control of various mechanisms and hydraulic control in a plant in accordance with the operating state.

FIG. 3 illustrates a switching control circuit for switching between speed control and torque control in a dynamometer. A dynamometer 1 serving as a power absorption load or the like from driving wheels of an automobile generates a driving / braking force by an output of a power converter 3 according to a control output of a speed / torque control amplifier 2.

In the speed / torque control amplifier 2, the set values of the speed setting device 4 and the torque setting device 5 are switched by the speed / torque changeover switch 6 at the time of manual setting, and are given as target values. The speed or torque set value is given a target value through the automatic / manual changeover switch 8.

[0006] A feedback signal to the speed / torque control amplifier 2 is supplied to a pulse pickup 9 and an F / V converter 10.
The speed / torque changeover switch 13 switches between the speed detection signal of the dynamometer 1 and the torque detection signal of the load cell 11 and the torque converter 12.

The changeover switches 6 and 13 are switched automatically by the programmable controller 7 or manually, and the control characteristic changeover switches 2A and 2B in the speed / torque control amplifier 2 are switched in conjunction with the changeover.

Further, a speed and torque detection signal is given to the programmable controller 7 and used as a state signal for adjusting and switching a program command value (speed or torque).

In the above configuration, for example, when switching from the speed control state to the torque control, a torque detection signal immediately before switching is read by the controller 7, and a manual or automatic torque set value is made to match this signal.
8, 13 and 2A, 2B are switched to the torque control side.

[0010] By such switching, occurrence of torque shock at the time of switching is prevented (bumpless), and after switching, the torque command is gradually changed to a new setting.

[0011]

In the conventional bumpless switching, it is difficult to make the manually set value coincide with the detected value at the time of switching the control system. Shock occurs.

In this regard, the switching by the automatic set value is easy to make the set value coincide with the detected value. However, a coincidence control circuit for this is necessary, and the change gradually changes to the target set value after the change. Requires a setting value adjustment circuit.

In the case of automatic switching, there is a tendency for a difference between the output timing of the command value and the switching timing of the switches 8 and 13 and the like. For example, although the command value and the switching command are output simultaneously, the switching is delayed due to the operation delay of the interface relay. Such a delay causes the operation in the control state before the switching and the set value after the switching, and causes a large output torque change in the dynamometer 1.

The torque shock at the time of switching as described above adversely affects the measurement of the dynamometer system, making accurate measurement and testing difficult, and the switching shock may damage the control target.

SUMMARY OF THE INVENTION An object of the present invention is to provide a switching control device which simplifies the device configuration while ensuring bumpless switching of the control system.

[0016]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a control system for controlling a control target by switching a plurality of control systems during operation. Circuits 18 _S , 18 _T for holding the control amplifier 2 _T of the control system in the same input / output state as the control amplifier 2 _{S of} the one control system; Hold circuit 1 that holds the output of control amplifier 2 _S of one control system and makes it a control output
6, the input of one control system is switched to the control state detection output of the other control system for the fixed time, and the input is used as the setting input of the control amplifier of the other control system. A time function circuit 20 is provided that obtains an output that has a cushion characteristic and matches the setting input of the other control system.

[0017]

[Function] The input / output states of the control amplifiers of a plurality of control systems are set to be the same, and when the control systems are switched, the control state of the control system up to that time is held by a hold circuit for a certain period of time.
Within this fixed time, the time function circuit gives the same value as the control state detection power of the other control system as the set value input of the other control system, and from this value, gives the other control system a set value input with cushion characteristics. To change to normal control when they match.

[0018]

FIG. 1 is a circuit diagram showing an embodiment of the present invention, in which the same components as those in FIG. 3 are denoted by the same reference numerals. The control amplifier is separated into a speed control amplifier 2 _S and a torque control amplifier 2 _T, and the outputs of both amplifiers 2 _S and 2 _T are switched by a changeover switch 15.
, And is further input to the control input of the power converter 3 through the hold circuit 16.

The hold circuit 16 always outputs the input signal as it is, holds the output when a hold command is given, and returns to the output of the input signal when the hold command is released.

The control amplifier 2 _S, 2 _T is the change-over switch 17 _S, 17 _T is provided on the input side, the deviation detector circuit 18 _S, 1
A deviation input from 8 _T can be captured. The deviation detection circuits 18 _S and 18 _T detect deviations between the output of the hold circuit 16 and the outputs of the amplifiers 2 _S and 2 _T.

By taking in the inputs from these deviation detecting circuits 18 _S , 18 _T , the amplifiers 2 _S , 2 _T normally make their outputs coincide with each other. For example, in the speed control state where the switches 17 _S and 17 _T are in the states shown in the figure, the output of the amplifier 2 _S matches the output of the hold circuit 16, and the output of the amplifier 2 _T matches the output of the hold circuit 16. that the differential output of the difference detection circuit 18 _T is adjusted so as to be zero.

The input to the speed control amplifier 2 _S or the torque control amplifier 2 _T is a time shift circuit 19 and a time function circuit 20.
And deviation calculation circuits 21 _S and 21 _T.

The time shift circuit 19 delays a manual or automatic set value given via the changeover switch 8 for a predetermined time, thereby inputting the set value and the switch 1
Synchronous switching that compensates for deviations from control switching command timings such as 3, 17 _S , 17 _T , and 15 is obtained. For example, the delay is set to a value obtained by adding a margin +10 ms to the delay time of the speed / torque switching signal with respect to the set value output from the programmable controller 7.

The time function circuit 20 always outputs the set value from the time shift circuit 19 as it is, and takes in and outputs a feedback signal from the speed / torque switch 13 for a fixed time (hold command period) during switching. Thereafter, when a time function run command is given, an output that gradually increases or decreases from the feedback signal to the set value input is obtained.

The deviation calculation circuits 21 _S and 21 _T calculate the deviation between the speed or torque set value from the time function circuit 20 and its detection signal, and obtain control inputs to the control amplifiers 2 _S and 2 _T.

The operation of this embodiment will be described in detail with reference to a time chart shown in FIG.

The programmable controller 7 has an ASR /
The switches 6 and 13 are switched between speed setting and speed detection or torque setting and torque detection according to the ATR command, and the switch 8 is switched between manual speed / torque setting or automatic speed / torque setting according to the manual / automatic command.

Each switch in FIG. 1 shows an automatic speed control state, and switching from this state to torque control and switching from torque control to speed control are performed at the timing shown in FIG.

In FIG. 2, when switching from speed control to torque control, the controller 7 switches the internal speed set value to the torque set value (time t ₁ ). This set value is a time t delayed by the time shift circuit 19 by a certain time Td.
Appears in ₃ .

This delay compensates for the delay of the relay for switching the switches 13 and the like in the set value switching and the control switching signals ATR and AST occurring almost simultaneously in the controller 7,
After the switching of the switch 13 and the like is completed, a set value switching signal is obtained.

When the switch 13 is switched by the generation of the signals ATR and AST (time t ₂ ), the switch 22
Is turned on for a predetermined time, and a hold command is given to the hold circuit 16.

When the switch 22 is turned on, the current torque detection value is taken into the input of the time function circuit 20, and this torque detection value becomes the output of the time function circuit 20 as it is.

On the other hand, the hold circuit 16 holds the control output based on the speed control state up to that time for a fixed time according to the hold command.

During this hold time, the switches 15, 17
_S, 17 _T is switched from the illustrated state. At this time, the output of the torque control amplifier 2 _T is switched in a state consistent with the speed control output, the input of the torque control amplifier 2 _T the output of the time to switching of the switch 17 _T function circuit 20 becomes the torque detection value The switching is maintained at zero, and no unnecessary vibration occurs.

At the end of the hold command period (time t ₃ )
The switch 22 is returned to the set value input side, but performs a cushion operation in which the output of the detected torque value is gradually shifted to the set value by the run command given at the same time. At the same time, the automatic control of the electric motor 1 in accordance with the output of the torque control amplifier 2 _T by hold release of the hold circuit 16 is resumed.

As a result, the process shifts to the torque control, and when the input and output of the time function circuit 20 match (time t ₄ ), the run command is released, and thereafter the automatic control according to the input of the torque set value is continued.

[0037] In the torque control state speed control amplifier 2 _S there switch 17 _S is in the ON state becomes an output that matches the output of the torque control amplifier 2 _T, also the input is zero.

Thereafter, when the torque control is switched to the speed control (time t ₅ ), the speed control is switched to the bumpless speed control in the same manner as the times t _{2 to} t ₄ .

Although the above-described operation is performed in the case of automatic setting, bumpless switching can be similarly performed in manual setting. Further, the controller side can use a standard output without adding a bumpless function to the command output and the setting output.

Although the embodiment shows a case where the speed control system and the torque control system are switched, it is needless to say that the present invention can be applied to the switching of other control systems.

[0041]

As described above, according to the present invention, the control amplifiers of a plurality of control systems are set to the same input / output state, and when the control systems are switched, the control state of the control system is maintained for a certain period of time. In the meantime, the same value as the control state detection output of the other control system is used as the set value input of the other control system, and after that, the set value input of the other control system is made to match the set value input of the other control system with a cushion characteristic. Bumpless switching can be performed with absolutely zero shock when switching the control system. Further, in terms of the circuit configuration, it is not necessary to add a bumpless function to the processing on the controller side, and it is sufficient to use a standard controller and add a few circuits to the control system.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing one embodiment of the present invention.

FIG. 2 is a time chart of the embodiment.

FIG. 3 is a conventional circuit diagram.

[Explanation of symbols]

1 ... dynamometer 2 _S ... speed control amplifier 2 _T ... torque control amplifier 7 ... controller 16 ... hold circuits 19 ... time shifting circuit 20 ... time function circuit.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) G01M 17/00-17/10 H02P 5/06 H02P 7/00

Claims (2)

(57) [Claims] 1. A control system for controlling a plurality of control target is switched during operation of the control system, the control amplifier of one of the control system of the control amplifier 2 _T of the other control system in a controlled manner by one of the control system 2 a circuit 18 _S, 18 _T held in the same output state _S, the control holds the output of the control amplifier 2 _S only the one control system a certain time when switching from one control system to another control system A hold circuit 16 serving as an output, and switching input from one input of the control system to a control state detection output of the other control system for the fixed time, and inputting the input as a setting input of a control amplifier of the other control system; A switching control device for a control system, further comprising a time function circuit 20 for obtaining an output which has a cushion characteristic and matches the setting input of the other control system from the setting input later. 2. The switching control apparatus for a control system according to claim 1, further comprising a time shift circuit for applying a set value of each of the control systems to the time function circuit with a delay of the predetermined time or more.