An active disturbance rejection control method for a six-degree-of-freedom electro-hydraulic vibration table

Abstract

The invention discloses a six-degree-of-freedom electro-hydraulic vibration table active disturbance rejection control method. The six-degree-of-freedom electro-hydraulic vibration table comprises three horizontal valve-controlled cylinder mechanisms, three vertical valve-controlled cylinder mechanisms, an upper platform and a lower platform. The method comprises acquiring the position, the velocity and the acceleration signal of each hydraulic cylinder piston rod in the six valve-controlled cylinder mechanisms, calculating a generalized disturbance compensation signal, and adjusting the driving signals of the valve-controlled cylinder mechanisms by using the generalized disturbance compensation signal so as to improve the control precision of a vibration table system. The control method provided by the invention can reduce the fluctuation of the amplitude-frequency characteristic of a lateral-degree-of-freedom acceleration closed-loop transfer function from 12dB to less than 3dB in the frequency band of 50 Hz, and obviously improves the control precision of the six-degree-of-freedom electro-hydraulic vibration table. The method has an operation cycle less than 1ms and can satisfythe experimental requirements of a vibration simulation system. Thus, the method is easy to be implemented through computer numerical control.

Description

technical field [0001] The invention relates to a vibration simulation experiment technology, in particular to an active disturbance rejection control method for a six-degree-of-freedom electro-hydraulic vibration table. Background technique [0002] Vibration simulation experiments reproduce the actual measured environmental vibration conditions in the laboratory to assess the structural reliability and operational reliability of the test piece under vibration excitation. It is currently widely used in aviation, aerospace, automobiles, construction and other industrial fields and departments. The electro-hydraulic vibration table is easy to realize the vibration excitation of low frequency, large displacement and large thrust. It has a firm structure and a large load capacity. It is often used in vibration simulation experiments of large structures or specimens. The control method of the electro-hydraulic vibration table is the core technology of the electro-hydraulic vibra...

AI Technical Summary

Problems solved by technology

Existing disturbance compensation control methods for a single valve-controlled cylinder mechanism cannot be directly applied to a six-degree-of-freedom electro-hydraulic shaker system

The analysis shows that when the traditional control method is adopted, affected by factors such as model uncertainty and interference force, the amplitude-frequency characteristics of the closed-loop transfer function of the lateral degree of freedom acceleration fluctuate by about 12dB in the 50Hz frequency band, which seriously affects the given signal in the 50Hz frequency band. Reproduction accuracy in this frequency band

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