Antiwindup Control of an Electrohydraulic System With Load Disturbance and Modeling Uncertainty

Abstract

In this study, a linear antiwindup controller of an electrohydraulic system (EHS) is proposed to drive the joint motion of a two-degree-of-freedom robotic arm. Since the unknown external load disturbance is caused by the driven force/torque of the robotic arm and some hydraulic parametric uncertainties existing in an EHS model, perhaps the control saturation emerges in the controller, which will degrade the dynamic performance and the stable margin of the EHS. Thus, a model recovery antiwindup compensator embedded in an unconstrained controller is designed to suppress the control saturation of a servo valve. The antiwindup effectiveness of the proposed controller has been demonstrated by a comparative experiment study with both linear and nonlinear controllers, which indicates the proposed controller can achieve better dynamic performance under largely unknown load disturbance and model uncertainty.