Discrete-time sliding mode control of a direct-drive robot manipulator

This paper investigates the application of an introduced discrete-time sliding mode algorithm in robot motion control. The algorithm was developed to ensure chattering-free discrete-time sliding mode control in finite time. Robustness against disturbances and modeling errors are the additional merits of this algorithm. Here, the algorithm is adapted for the robot motion control problem, and it is used to design feedback controllers of a benchmark direct-drive robot. Theory and experiments confirm the applicability of the algorithm. However, they also reveal restrictions in controller tuning that may result in undesirable amplification of noise and in excitation of parasitic dynamics.