Chattering Reduction in VSC Systems of Robotic Manipulators

Abstract

The sliding mode motion design is considered for the nonlinear plants linear with respect to the control input. The dynamics of the robotic manipulators is treated with and without the dynamics of the actuators. When the dynamics of the actuators is included, design of the sliding modes for the systems with discontinuous control is performed. If actuators dynamics is neglected the control is assumed to be continuous quantity. By combining variable structure systems and Lyapunov design a new discrete-time algorithm has been developed. It possesses all the good properties of the sliding mode systems and avoids the unnecessary discontinuity of the control input, thus eliminating chattering. Neither the explicit calculation of the equivalent control nor the implicit high gain feedback inside the boundary layer are used. Control parameters depend on the plant gain matrix and on the gradients of the sliding mode manifold. Simulations justify the solutions developed in this paper.