Variable structure model-reaching control strategy for robot manipulators

A control strategy named model-reaching control is applied to control the motion of robot manipulators. It is proposed to achieve this goal using the theory of dynamic variable-structure systems. For this purpose a dynamic compensator is introduced, forming the switching function such that the dimension of the sliding mode equals that of the manipulator system. The resulting motions of the system reach and stay on the desired motion of an ideal model. In this manner, good dynamic performance of the sliding mode can be prescribed. Several reaching strategies are proposed to steer the trajectory towards the sliding manifold. The associated reaching conditions are specified such that the desired motion of the model can be reached in a finite interval of time. A variety of algorithms are recommended to govern the rate of reaching the model while satisfying the reaching conditions