A new type robust adaptive control for electric hydraulic servo system

This document explains and demonstrates the mismatched uncertain nonlinear system control problem. Combing the Backstepping algorithm with sliding mode control, we present a robust adaptive sliding mode control. Design sliding mode control recursive, and finally get the virtual control input value. Meanwhile, CMAC learns system' uncertainty as well as the derivative information of each order virtual control on-line. Because the conventional sliding mode control uses sign function as switching function, which easily leads to chattering phenomenon. Therefore, we apply hyperbolic tangent function instead of sign function as sliding mode switching function, to avoid the possible chattering problem owing to discontinuous terms. Finally, the proposed control algorithm is applied to the electric hydraulic servo system, and is verified by simulation.