Chattering Elimination With Second-Order Sliding Modes Robust to Coulomb Friction

Abstract

In this paper, a solution to the regulation problem of mechanical systems in presence of Coulomb friction is proposed. The control objective is attained by means of continuous control signals designed according to a second-order sliding mode algorithm. The proposed solution avoids the main drawback presented by the standard first-order sliding mode control, that is the chattering phenomenon which is due to the unavoidable presence of non idealities and to the discontinuous nature of the control signals. The proposed algorithm is proved to be efficient in counteracting discontinuous disturbances such as friction. [S0022-0434(00)00704-8]