Stable condition derivation method of electrical-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 the stability condition 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. The reliability of its work is the key to ensuring high-precision, high-speed, continuous and stable operation of the equipment. In the industrial field, it is widely used in construction machinery actuator control system, steel rolling machinery hydraulic pressure system, manipulator control system, etc.; in the defense field, it is widely used in missile automatic control system, radar tracking system, and aircraft rudder surface control system , The steering gear of ships and the stabilizing device of tank artillery. Once the system loses stability, it will cause downtime or affect product quality, and at wo...

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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