Nonlinear robust adaptive control of electro-hydraulic system

Based on Lyapunov method, a nonlinear robust adaptive control scheme is proposed for an electro-hydraulic system to reduce the influence of the systems uncertain parameters and uncertain model. Firstly, the control objective function is defined. Then, on the base of the control objective function, the adaptive controller and the parameters update laws are presented via using Lyapunov stability method and a simple robust method is introduced to compensate the model uncertainty. The proposed control scheme is simple and insensitive to parameter and model uncertainties. In addition, the controller is smooth and does not cause chattering phenomena. Simulation results show that the control approach can improve tracking accuracy effectively and the theory analysis is correct.