Chattering elimination with second-order sliding modes robust to coulomb friction

In this paper, a solution to the regulation problem of mechanical systems i n presence of Coulomb friction is proposed. The control objective is attain ed by means of continuous control signals designed according to a second-or der sliding mode algorithm. The proposed solution avoids the main drawback presented by the standard first-order sliding mode control, that is the cha ttering phenomenon which is due to the unavoidable presence of non idealiti es and to the discontinuous nature of the control signals. The proposed alg orithm is proved to be efficient in counteracting discontinuous disturbance s such as friction. [S0022-0434(00)00704-8].