Application of a new adaptive robust controller design method to electro-hydraulic servo system

This paper proposes a new design method of adaptive robust controller and applies it to a valve-control-cylinder electro-hydraulic servo system. Firstly, the system is fully derived in the state-space form, which includes all the certain, uncertain, known, unknown, linear and nonlinear terms of the system. Then the adaptive robust controller designed by the new method is employed, together with the chosen adaption laws, to deal with all the elements of the modeled mathematical system. The proposed controller is obtained by designing a control state-space expression with auxiliary control components and a state observer. Under an arbitrary given trajectory, all the system states will converge to the desired states through designing the appropriate auxiliary control components. Lyapunov method is utilized to strictly prove the convergence and stability of the system. Finally, a hardware platform of the system is set up and comparative experiments with the adaptive robust controller are implemented to verify the effectiveness and advantages of the proposed method.