Robust hybrid dynamic control of robot arms

The sliding mode technique is used to overcome the need for an accurate robot model. The independent linear task-space controllers of force and velocity are designed in the discrete-time domain, taking explicitly into account delays due to control computation. Additional integral control can be included to compensate for a reduced knowledge of the environment geometry or to deal with unmodeled terms. The resulting control law is simple enough to be implemented in real time. The robustness of the control scheme is confirmed by realistic simulations for a two-link robot arm moving along a circular surface in the vertical plane