Sliding mode control with perturbation estimation: application to motion control of parallel manipulator

Sliding mode control(SMC) incorporated with perturbation compensation is de veloped here to reduce the low-frequency tracking error in the presence of wide-band frequency perturbations for a nonlinear dynamic system. The contr ol scheme is then applied to the motion control of a two-degree-of-freedom (DOF) parallel manipulator, utilizing its reduced dynamics for real-time im plementation. It is shown that the SMC with perturbation compensation is fa r superior to the conventional SMC in tracking control of the manipulator u nder large payload and external disturbance conditions. (C) 1998 Elsevier S cience Ltd. All rights reserved.