Sliding mode adaptive control of electro-hydraulic system with nonlinear unknown parameters
含有非线性不确定参数的电液系统滑模自适应控制

An adaptive sliding control method is proposed for an electro-hydraulic system with nonlinear unknown parameters. The proposed control method is for designing a nonlinear adaptive controller with adaptation laws to compensate the nonlinear uncertain parameters due to the uncertainty of the original controlled volumes. Firstly, we developed a novel type Lyapunov function to construct an asymptotically stable adaptive controller and present the adaptation laws of nonlinear uncertain parameters. Then, by combining sliding mode control with a simple robust method, the sliding mode adaptive controller with parameters update laws of the electro-hydraulic system is designed, which can compensate the system for uncertain nonlinearities, linear uncertain parameters and especially nonlinear uncertain parameters resulted from the uncertainty of the original controlled volumes. Finally, the experimental results show that the nonlinear control algorithm, together with the adaptation scheme, gives a good performance for the specified tracking task in the presence of unknown nonlinear parameters.