Variable structure control of manipulator using linear time-varying sliding surfaces

This paper proposes a new variable structure controller (VSC) for the accurate tracking control of a manipulator using the variable boundary layer. Up to now, VSC applying the variable boundary layer did not remove chattering from an arbitrary initial state of the system trajectory because VSC has used the fixed sliding surface. But, by using the linear time-varying sliding surfaces, the scheme has the robustness against chattering from all states. This scheme can be applied to the second-order nonlinear systems with parameter uncertainty and extraneous disturbances, and have better tracking performance than the conventional method. To demonstrate its performance, the proposed control algorithm is applied to a two-link manipulator.