Chattering-free sliding mode control for a class of nonlinear mechanical systems

Second-order sliding mode control (2-smc) and dynamic sliding mode control (dsmc) eliminate the disturbing characteristic of chattering in static slid ing mode control under the assumption that the derivative of the sliding su rface is available or complex inequalities at the acceleration level can be constructed. In this paper, passivity-based adaptive and non-adaptive chat tering-free sliding mode controllers are proposed assuming that the upper b ound of the norm of the derivative of the sliding surface is available, a w eaker and easy to implement assumption in comparison to those of 2-smc and dsmc. The closed-loop system accounts explicitly for the invariance conditi on without reaching phase, and therefore far a desired transient response w ith global exponential convergence of tracking errors. Preliminary experime nts are presented. Copyright (C) 2001 John Wiley & Sons, Ltd.