Derivation Method of Stability Conditions for Electro-hydraulic Position Servo System

Abstract

The invention provides a stable condition derivation method of an electrical-hydraulic position servo system. The method comprises steps of (1) according to an electrical-hydraulic position servo system mathematical model and a model information transmission relation, deriving a relational expression 1 between load displacement disturbance quantity and servo valve valve-core displacement disturbance quantity; (2) according to the displacement feedback and a mathematical model of a control part of the electrical-hydraulic position servo system, deriving a relational expression 2 between load displacement disturbance quantity and servo valve valve-core displacement disturbance quantity; (3) according to a transmission relation derived through the relational expression 1 and the relational expression 2, establishing a transmission block diagram of disturbance quantity of a position closed loop system; (4) by sue of Popov frequency criterion, determining the absolute stability during position closed loop control; and (5) according to the Popov principle, deriving an absolute stability condition of the electrical-hydraulic position servo system. According to the invention, based on a traditional transmission function, difficulties in reconstructing decision functions are avoided and the absolute stability condition of the electrical-hydraulic position servo system can be quickly andprecisely derived.

Description

technical field [0001] The invention relates to the technical field of hydraulic system stability judgment, in particular to a method for deriving stability conditions of an electro-hydraulic position servo system. Background technique [0002] The electro-hydraulic position servo system is the core control system of industrial equipment and national defense equipment, and its working reliability is the key to ensure high-precision, high-speed, continuous and stable operation of the equipment. In the field of industry, it is widely used in the control system of construction machinery actuators, the hydraulic pressing system of steel rolling machinery, the control system of manipulators, etc.; in the field of national defense, it is widely used in the automatic control system of missiles, the tracking system of radar, and the rudder surface control system of aircraft , the steering device of the ship and the stabilization device of the tank artillery, etc. Once the system is...

AI Technical Summary

Problems solved by technology

However, the theoretical derivation of the stability conditions of the electro-hydraulic position servo system is still relatively rare.

The system stability criterion based on the Lyapunov method is only a sufficient condition for judging the stability of the system, which has a certain degree of conservatism, and it is not easy to construct the required Lyapunov function in the application

However, the electro-hydraulic position servo system is a typical nonlinear closed-loop control system with many influencing parameters. The dynamic characteristics are complex and changeable, and there are many factors affecting its stability. If it loses stability, it will definitely affect the vibration characteristics of its load.

When the system is in a certain working state, it is very likely to induce nonlinear vibration. If the stable conditions cannot be effectively grasped and effectively controlled in a timely manner, it is likely to cause a major vibration accident in the system.

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