Realization method of nonlinear robust position controller for electro-hydraulic servo system based on discontinuous projection mapping

Abstract

The invention belongs to the field of electromechanical hydraulic servo control, and provides a discontinuous projection mapping-based implementation method for the nonlinear robust position controller of an electro-hydraulic servo system. The method considers the uncertainty of the parameters of the system and the uncertainty of the external interference to establish a nonlinear model of the system. Meanwhile, for the uncertainty of the parameters of the system, unknown parameters are estimated accurately according to the parameter adaptive algorithm designed based on discontinuous projection operators, so that the estimated values of parameters are always within a known region. By means of a controller designed by introducing an auxiliary function, the robustness is ensured to be good for the external interference of the system and the uncertainty of unmodeled dynamics and the like. The controller is a full-state feedback controller, and enables the asymptotic tracking function for the position output of the electro-hydraulic servo system. Even when the time tends to be infinite, the tracking error is ensured to be zero. The controller designed in the invention is continuous in control voltage, and can be better applied in the practical engineering application.

Description

technical field [0001] The invention relates to a controller, in particular to a method for realizing a nonlinear robust position controller of an electro-hydraulic servo system based on discontinuous projection mapping, and belongs to the field of electro-mechanical-hydraulic servo control. Background technique [0002] Electro-hydraulic servo systems are widely used in aviation, aerospace, automobiles, ships, and construction machinery due to their outstanding advantages such as large power-to-weight ratio, fast dynamic response, good pressure and flow controllability, and flexible power transmission. With the development of these fields and the continuous improvement of the technical level, there is an urgent need for a high-performance electro-hydraulic servo system as a support, and the control performance obtained by the traditional linearization method cannot meet the system requirements gradually. The nonlinearity of the electro-hydraulic servo system, such as pressu...

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Problems solved by technology

[0008] The present invention solves the problem that the nonlinear model of the simplified system is linear or ignores the uncertainty of the system modeling in the control of the existing electro-hydraulic servo system, the phenomenon of high gain feedback exists in the traditional adaptive robust control, and the problem of parameter uncertainty and uncertainty exists at the same time. A deterministic nonlinear system can only ensure that the tracking error is bounded. At the same time, the design of a robust adaptive controller based on the error sign integral is relatively complex and can only guarantee the semi-global asymptotic stability of the entire system and cannot guarantee parameter estimation in complex environments. For the problem that the value is always in a bounded area, an implementation method of nonlinear robust position controller for electro-hydraulic servo system based on discontinuous projection mapping is proposed

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