Nonlinear Robust Position Control Method for Electro-hydraulic Servo System with Time-Varying Output Constraints

Abstract

The invention provides a nonlinear robust position control method for an electro-hydraulic servo system with time-varying output constraints. The electro-hydraulic position servo system is selected as the research object, and a nonlinear model of the system is established, taking into account external disturbances of the system, etc. Uncertainty of the model; Uncertainties such as unmodeled disturbances are estimated through the extended state observer and combined with the backstepping control method for feed-forward compensation, which improves the robustness of the actual electro-hydraulic position servo system for external disturbances; the present invention is Full state feedback control, and the nonlinear robust controller designed by the time-varying asymmetric obstacle Lyapunov function can carry out time-varying asymmetric constraints on the output position tracking error, and has greater flexibility; the nonlinear robust controller designed by the present invention The control voltage of the robust controller is continuous, which is more conducive to the application in engineering practice.

Description

technical field [0001] The invention relates to the field of electro-hydraulic servo control, in particular to a nonlinear robust position control method of an electro-hydraulic servo system with time-varying output constraints. Background technique [0002] Electro-hydraulic servo systems are widely used in industry, national defense and other fields due to their outstanding advantages such as high power density, fast dynamic response, large output force / torque, and strong load stiffness. With the continuous advancement of the technical level in these fields, there is an urgent need for high-performance electro-hydraulic servo systems as support, and the control performance obtained by traditional linearization methods cannot meet the system requirements gradually. The nonlinearity of the electro-hydraulic servo system, such as servo valve pressure flow nonlinearity, pressure dynamic nonlinearity, friction nonlinearity, etc., has gradually become a bottleneck factor that li...

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Problems solved by technology

[0009] The present invention solves the problem that the simplified system nonlinear model in the existing electro-hydraulic servo system control is linear or ignores the uncertainty of system modeling, high gain feedback, vibration phenomenon based on the traditional sliding mode control method, and the inability to arbitrarily constrain the output tracking error. Tolerance problem, a nonlinear robust position control method for electro-hydraulic servo system with time-varying output constraints is proposed

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