JPS58103009A - Method and apparatus for control efficiency of hydraulic servo mechanism - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention improves the control efficiency of a hydraulic servomechanism, in particular a position-controlled mechanism, with a control circuit having an operating cylinder, a servo valve, a regulator, a setpoint value transmitter and an actual value transmitter. The present invention relates to a method and apparatus for improving the quality of the image.

The control of the servo valve, i.e. the displacement of the valve spool from the central pre-neutral position, is controlled by the connected 71n, if no force acts on the operating piston (in so-called operation without load pressure). l'+1 to the speed of the operating piston in the pressure operating cylinder! It is theoretically comparable. A pressure called load pressure is generated in the working medium of the working cylinder due to acceleration, extension, external force, etc. The load pressure is especially high and the piston speed is high! I quality: When fIi is large, servo valve control and operating piston speed 18. (excitation rate). This non-linearity excites higher harmonic vibrational modes that are distorted when simulating displacement signals, velocity signals and especially force sentinel signals or functions.

In the past, these difficulties could not be overcome, or could not be completely overcome, with hydraulic servo control circuits. It is known to use the differential pressure ΔP in the cylinder chamber of the working cylinder as the auxiliary force II. Therefore, the ΔP times signal of the I-value band is added to the actual predetermined value of the position control circuit. With such an arrangement, the resonance J%QNl number of the hydraulic servo yarn is well damped. However, the return of one amount of auxiliary control does not affect the nonlinearity caused by the load pressure dependence, and simply ^IAI ′l
It is best to perform linear correction of the 1ri instrument code.

In conventional 4n methods and devices, a control signal for a control circuit is derived from the transmission characteristics of the control circuit and a desired signal or function. In this case, it is necessary to analyze and simulate the system, which requires many hours of human time.In such cases, it is disadvantageous that the computer can only process signals with a limited time length.Load pressure compensation is performed by correcting the target value signal.

(3) The purpose of the present invention is to eliminate the drawbacks of the prior art, improve the control efficiency, especially the opening side efficiency of the position side example type hydraulic servo system, and reduce the strain caused by the load pressure (C) in the operating cylinder. (also called distortion rate), especially when balancing acceleration signals or functions, or also when controlling displacements and velocities.Fourth, to reduce the load on the regulator. .

This object is achieved by the method and device as defined in the claims. The claims also include embodiments of the invention.

It has been found that the control characteristics can be significantly improved by multiplying the output signal of the regulator by a correction signal formed from the load pressure or its equivalent. The narrow surface I is preferably formed based on the formula set forth in claim 2. The corrected output signal of the regulator can be further improved by taking into account the transfer function of the servo valve.

Another advantage of the invention is that the temporal length of the signal that can be processed is Tltl! (4) The structure of the compensation circuit is simple, and the compensation circuit remains unchanged after adjustment, and F! l■ Essential control signal detector (
Load pressure, acceleration detectors, valve spool displacement detectors of control valves) can be easily installed, or can be easily used as already provided in the hydraulic servo system.

Let's take a closer look at the history of one embodiment of the present invention with reference to the drawings.
Do 1.

The control circuit of the present invention mainly includes a target value transmitter S that provides a target value W to the regulator R, and an output signal W of the regulator R.

A multiplier unit that performs multiplication by auxiliary 1E and auxiliary number C, a servo valve transfer function correction unit 'BV, a servo valve SV for controlling the operating cylinder, and an operating cylinder 2 that balances a desired target value or target value function. It consists of In the case of cancer control system, which is ranked in history,
In the working cylinder 2, the actual value 11@x is detected in the form of a displacement of the piston rod of the cylinder.

The actual value X is sent to a regulator R in which a comparison is made between the setpoint value W and the actual f+M X. Multiplier M,
Other than this, this arrangement is equivalent to a known control circuit.

Adding 7 to 2 LFiτj described in claim 2
Q Ff! To do this,: Jit + load pressure P in the previous cylinder z.

is detected. However, here, K is the proportionality constant, and P8 is the supply pressure. This pressure detection can be carried out, for example, by means of a differential pressure detector, which is then connected to the two cylinder chambers of the working cylinder Z and supplies a suitable electrical signal to the circuit.

Instead of the load pressure, the acceleration of the piston or piston rod of the working cylinder 2 can also be detected by means of a suitable detector. This is possible in systems where the mass is rigidly coupled to the piston. The ratio PJ/Ps of the load pressure P and the supply pressure P8 is in this case replaced by an acceleration derived from the acceleration, for example in the form of a suitable electrical signal.

The load pressure signal P is multiplied by a proportional constant that can be given in advance or adjusted from an external constant setter F'G in a first multiplier M1. The stability of the compensation circuit is adjusted by the proportionality constant. The value of the proportionality constant is between 0 and 1. This value is supplied to the circuit as an electrical signal. The supply pressure P can be fixedly adjusted within the circuit, but its regulation can also be made variable if necessary. Adjustment?
When o, the compensation circuit is disabled and the A bias correction signal in the corrector is equal to one. That is, the load pressure signal Pl
! is not corrected. In the device of the present invention, in addition to the load pressure Pl,
The valve spool position of v is also detected and the actual value of the spool position, Xsv, is used to control switch sw'1. The switches sw&'f and the second multiplication (1) section Mdru switch SW are always operated or switched λ when the spool of the servo valve SV passes through the center position.

Since the load pressure P, is dependent on the prefix, the correction signal must also be made dependent on the control direction of the servo valve SV.

Another @ Santo A in history, and compensation circuit Ms''' through A
The output signal of the C regulator R is multiplied. Further improvement can be achieved by using the output signal w of the multiplication unit (7) M and the transfer function correction unit Fsv of the H servo valve 8v.

Before the output signals W, U are sent to the servo valve SV itself, they are multiplied by feedback, for example, by the measured reverse twist width characteristic of the servo valve SV.

Instead of the servo valve SV, a proportional valve can also be used in the method and device according to the invention. Instead of a position-side control circuit, a control circuit may be provided, for example with a speed control system or a mixed control system.

The illustrated compensation circuit can advantageously be assembled with the regulator or integrated into the regulator housing in the device described above, and thus effectively forms part of the regulator (7, e.g. on a printed circuit board). It can also be configured as a shape.

[Brief explanation of drawings]

The figure is a block diagram showing one embodiment of a compensation circuit according to the invention in a position-controlled hydraulic servo control circuit. P... Load pressure, R... Controller, S... Target value transmitter (8), SV... Servo valve, W,... Output signal, Z...
・Motion cylinder applicant Kiyoshi Inomata

Claims (1)

Claims: 1) Method for improving the control efficiency of a hydraulic servomechanism, in particular a position-controlled mechanism, with a control circuit having an operating cylinder, a servo valve, a regulator, a setpoint value transmitter and an actual value transmitter. In this step, a correction signal is formed from the load output or its equivalent control amount, and the nonlinearity between the control eA1 of the servo valve and the flow control of the valve, which occurs in the operating cylinder due to the load pressure, is compensated for by forming a correction signal from the load output or its equal control amount, and adding a controller to the correction signal. A method for improving the control efficiency of a hydraulic servo mechanism, characterized in that the control efficiency of a hydraulic servomechanism is improved by multiplying output signals. 2) The correction signal MC of the load pressure is expressed as K=proportionality constant (<the method according to claim 1, which is characterized by I.O of the patent claim characterized in that it is modified by
1, Section 1 or Section 210. 4) A hydraulic servo mechanism equipped with a control circuit that has an operating cylinder, a servo valve, a control circuit, and an eye (required value transmitter, real V, and 4-value transmitter), especially the control efficiency of the control type mechanism. Several devices are provided with a compensation circuit having an input end for a load pressure signal or an acceleration surface signal, an input end for a servo valve spool position signal, and an input end for a proportional constant signal, and the opening side one circuit and the compensation circuit are connected to each other. A transmitter for input signals is provided in each of the
Previous H: Control efficiency of a hydraulic servo mechanism, characterized in that the compensation circuit has a control section that forms a correction signal and a multiplication section that receives and receives the correction signal and the controller. 5) The device according to claim 4, wherein the Ail recording compensation circuit has a packaging part for servo valve transmission. 6 ) The device according to claim 4 or 5, wherein the compensation circuit is part of a regulator.