Nonlinear control method of electro-hydraulic system driving Two-DOF robot arm with output constraint

Abstract

Abstract This paper studies tracking control problem for a certain parameter electro-hydraulic system(EHS) to constrain the output cylinder position in prescribed performance. In the control design, a backstepping controller is adopted to guarantee the system stability and the dynamic tracking performance. The dynamic surface control (DSC) is used to eliminate the complexity explosion of virtual control repeatedly derivatives to make the controller and parameter design simple. A barrier Lyapunov function (BLF) is employed in the process of control design to avert the contravention of the time-varying output constraints. The comparative simulation results are given to demonstrate that the effectiveness of the proposed controller. Furthermore the smooth dynamic surface is obtained to guarantee the sufficient stable margin of EHS.