JPS62190501A - Servo system - Google Patents

Abstract

PURPOSE:To prevent the variance of responsiveness and accuracy due to the influence of the nonlinear characteristic of a control system by setting automatically the control gain of a compensating means to an optimum value in response to a reference input. CONSTITUTION:A command signal (i) outputted from a controller 7 is inputted to a servo valve 17 through a servo amplifier 16. The valve 17 controls the flow rate of oil supplied to a hydraulic motor 9 in response to the output signal of the amplifier 16. A feed quantity generator 71 receives a rolling end signal (p) to generate a feed quantity command delta during an idle period. A subtractor 72 subtracts a rotation angle detection signal (f) from the command DELTA to send a deviation signal (e). A compensator 73 compensates the deviation signal (e) on a basis of a control signal (c) to output a compensated signal required for desired operation of the hydraulic motor 9 as a command signal (i). An automatic gain adjuster 74 receives the feed quantity command delta to send a gain switching code (control signal) (c) which selects a control gain of the compensator 73.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a servo system.

[Conventional technology]

In general, this type of sensor system includes a reference input sending means for sending out a reference input for operating the control system, a detection means for detecting the control amount of the controlled object and sending out the main feedback signal, and a A subtracting means for subtracting the main feedback signal and sending out an operating signal, a compensating means for compensating the operating signal so that the control system performs the desired function and sending out a compensation signal, and controlling by converting the compensation signal into a manipulated variable. It has an operation means for acting on the target.

Conventional compensation means have a constant control dyne.

[Problem that the invention seeks to solve]

Therefore, there is a drawback that the response and accuracy of the control system varies by 74 degrees depending on the reference input due to the influence of the nonlinear characteristics of the control system.

[Means for solving problems]

The sensor system according to the present invention has a compensating means 75E, a plurality of different control chains, a selection means for selecting one of the control chains, and a control signal for controlling the selection means in accordance with a reference input. The present invention is characterized in that a control signal generating means is added.

[For production]

Since the optimum control gain of the compensation means can be automatically set according to the reference input, it is possible to construct a servo system having uniform responsiveness and accuracy over all the reference inputs.

[Embodiments] Two embodiments of the present invention will be described below in detail with reference to the drawings.

Referring to FIG. 4, there is shown in a perspective view the construction of a pilger mill to which the present invention is applied.

The rolling mechanism consists of a main motor 1, a crankshaft 2 connected to the main motor 1, and a roll stand 3 connected to the crankshaft 2 that can move back and forth. A rack and pinion 5 is force-coupled to the rotating shaft of a pair of upper and lower rolls 4, 4 built into the roll stand 3.
4. The roll stand 3 is reciprocated multiple times by forward and backward movement.

The feed mechanism 10 includes a feed carriage 10a provided on the material entry side of the roll stand 3;
The feed screw 10 is composed of a feed screw 10b that is screwed into the feed screw 10b.
b is driven by a hydraulic motor 9 connected via gears. The feed lever 10b is movable only in the circumferential direction and not in the axial direction.

The rotation mechanism is a mandrel rot chuck 12 that can rotate twice.
and a rotatable inlet chuck 13 and an outlet chuck 14 provided on the material inlet side and the material outlet side of the roll stand 3.
These are driven by a drive motor 8 connected via a power transmission mechanism such as gears. Whereas the mandrel rod chuck 12 completely fixes the mandrel.

The inlet chuck 13 and the outlet chuck 14 allow circumferential movement of the material to enable material feeding.

In other words, only rotational movement is restricted, while axial movement of the material is permitted.

A rotation angle detector 15 is attached to the hydraulic motor 9. The rotation angle detector 15 detects the rotation angle of the hydraulic mower 9 and sends a rotation angle detection signal (main feedback signal) f to the control device 7.

The control device 7 receives the rolling end signal p, and based on this signal, controls the drive motor 8 and the hydraulic motor 9 during the so-called idle period from the end of one rolling process to the start of the next rolling process.
Sends a command signal to operate the

Referring to FIG. 1, there is shown a block diagram of an embodiment of a servo system according to the present invention. This embodiment is an example in which the present invention is applied to a hydraulic motor 9 that drives a feed mechanism 10 of a pilger mill.

The command signal 1 output from the control device 7 is sent to the amplifier 1.
6 to the servo valve 17. The servo valve 17 responds to the output signal of the servo amplifier 16 to control the hydraulic motor 9.
Controls the flow rate of oil pumped into.

The control device 7 includes a feed rate generator 71. Subtractor 72° Compensator 73. and an automatic gain adjuster 74. The feed amount generator 71 receives the rolling end signal p.

A feed amount command (reference input) δ is generated during the idle period. A subtracter 72 subtracts the rotation angle detection signal f from the feed amount command δ and sends out a deviation signal (operation signal) e. Compensator 73
compensates for the deviation signal e based on a control signal C, which will be described later, and outputs a compensation signal necessary for the hydraulic motor 9 to perform the required function as a command signal 1. The automatic gain adjuster 74 receives the feed amount command δ and sends out a gain switching code (control signal) C for selecting the control gain of the compensator 73.

Referring to FIG. 2, a specific example of the configuration of the compensator 73 is shown. The illustrated compensator 73 includes a switch 731. of the switch 731 (
n+1) output terminals to control each
Dyne compensation elements 732o-732n with o-Kon
, and transfer function (T2 S+1 )/(TIS +1
). 1T here
1, T2 is a phase compensation time constant, and S is an operator in Laplace transform.

Referring to FIG. 3, a specific example of the configuration of the automatic gain adjuster 74 is shown. The illustrated automatic gain adjuster 74 includes:
Feed amount gain switching points δ0 to δn are set (n+1)
Setting devices 7410 to 7411 e Setting devices 741o to 7
(n+1) comparators 742° to 742nt and comparators 7428 to 7, which compare the output of 41n and the feed amount command δ;
It consists of a gain switching code generator 743 that sends a jig-in switching code C to the switching device 731 of the compensator 73 from the output turn of 42n.

However, δo×δ1×δ. It is.

Next, the operation will be explained.

When it is determined that the rolling end signal p indicates that the shear idle is in the middle, the feed amount generator 71 generates the feed amount command δ.

At this time, the outputs of the comparators 7420 to 742n are all at a low level "L", and the gain switching code generator 743 outputs a signal for selecting the gain compensation element 7320 as the dyne switching code C. Therefore, the compensator 73 The transfer function of is θ.(TZS+1)/(TIS+1).

On the other hand, the subtracter 72 takes the difference between the feed amount command δ and the rotation angle detection signal f, and sends the deviation signal a (e=δ−f) to the compensator 73.
Send to. The compensator 73 performs gain compensation and phase compensation using the transfer function, and sends a valve opening command (compensation signal) for the servo valve to the servo amplifier 16. The servo amplifier 7'16 operates the valve opening degree of the servo valve 17 in accordance with this command, and controls the rotation angle (control amount) of the hydraulic motor 9.

The rotation of the hydraulic motor 9 is transmitted to the feed mechanism 10, and the material feed operation is started.

When the feed amount command δ exceeds the feed amount gain switching point δ0 due to a change in the feed amount command, and becomes δo - δ minus δ1.

Only the output of the comparator 742o changes to 1H''.As a result, the gain switching code generator 743
The dyne switching code C controls the dyne switch 731 to select the gain compensation element 7321. Therefore, compensator 7
The transfer function of 3 is K. 1(T2S+1)/(TI
S+1).

In this way, the control gain K (7) of the compensator 73 can be automatically set to the optimum value according to the feed amount command δ. - A mill feed control system can be realized.

It goes without saying that this system can also be applied to the drive motor 8 that drives the rotation mechanism of the Pilgami Mill. By applying this system to both the rotation mechanism and feed mechanism of a pilger mill, a shell drive system with uniform responsiveness and precision is realized, improving productivity during material rolling. Quality can be stabilized. Further, the motor to be controlled is not limited to a hydraulic motor, but may be an electric motor. Furthermore, the control device 7 may be configured with a microcomputer, in which case the value of the feed amount gain switching point and the value of the control gain can be easily changed to desired values by a program. It goes without saying that the present invention can also be applied to servo systems other than pilger mills.

〔Effect of the invention〕

As is clear from the above description, there are two aspects of the present invention.

By automatically setting the control gain of the compensation means to the optimum value in response to the reference input, it is possible to prevent variations in responsiveness and accuracy due to the influence of nonlinear characteristics of the control system.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the servo system according to the present invention, FIG. 2 is a block diagram showing a specific example of the configuration of the compensator shown in FIG. 1, and FIG. A block diagram showing a specific configuration example of an automatic gain adjuster, FIG. 4 is a pilger to which the servo system shown in FIG. 1 is applied.
FIG. 1 is a perspective view showing an example of the configuration of a mill. 7... Control device, 71... Feed amount generator, 72...
- Subtractor, 73--Compensator, 74--Automatic gain adjuster. 9... Hydraulic motor, 10... Feed mechanism, 15...
Rotation angle detector, 16... servo amplifier, 17... servo valve.

Claims (1)

[Claims] 1. Reference input sending means for sending out a reference input for operating the control system; detection means for detecting the control amount of the controlled object and sending out the main feedback signal; and subtracting the main feedback signal from the reference input. subtracting means for sending out an operating signal; compensating means for compensating the operating signal so that the control system performs a desired function and sending out a compensation signal; and converting the compensation signal into a manipulated variable to act on the controlled object. a servo system comprising: a selection means for selecting one of a plurality of control gains of the compensation means; and a control signal generation for generating a control signal for controlling the selection means in response to the reference input. A servo system having means.