Application of VSC in position control of a nonlinear electrohydraulic servo system

The hydraulic servomechanism is widely used in manufacturing machinery, heavy-duty machine and the automobile industry. The variable structure control (VSC) is one of the major approaches in dealing with the nonlinear systems. In this paper, we apply the technique of the variable structure control to an electrohydraulic servo control system which is described by a third-order nonlinear equation with time-varying coefficients. First, we construct a two-phase variable structure controller to get the precise position control of an electrohydraulic servo system. Second, we compare the performance among three different types of VSC controllers. Finally, the jerks of the state trajectories will be discussed in the simulation results. (C) 1998 Elsevier Science Ltd.