Robot robust path tracking

A new discontinuous robust control law for a rigid manipulator with bounded parameter uncertainties to track a desired trajectory is presented. Global exponential stability is proved by the use of a natural Liapunov function based on a transformation of the manipulator's differential equation due to Slotine and Li (1987). Convergence is to a sliding mode along which the tracking error is reduced at an arbitrary exponential rate. It is also shown how adaptation of bounds on uncertainties, and parameter adaptation, can be incorporated. For a continuous approximation of the discontinuous control law, practical stability (essentially, global uniform ultimate boundedness) of the tracking error is proved. Simulation results for the continuous control law exhibit excellent robust tracking. (Author)