On sliding mode control of uncertain mechanical systems

A sliding mode control law is proposed for regulation control of a class of uncertain mechanical systems. The algorithm uses only the bounds of uncertainties and disturbances and does not require matching conditions. The existence of a sliding mode, its closed loop stability, and its robustness characteristics are proved by using Lyapunov's stability theory. The proposed control is shown to be robustly stable with respect to parameter variations and external disturbances. Examples are given to demonstrate the application and performance of the proposed approach.