Chattering-free sliding-mode tracking control for robotic manipulators

In this paper the tracking control problem for robot manipulators is addressed and solved by using a second order sliding mode control methodology. Unless other variable structure control schemes, the control torques are continuous functions of time, with no need for smoothing filters that cause a degradation of the performance as well as potential instability. A novel scheme is proposed, that accomplishes the control task using for feedback the joint position and velocity and relying on a weak informations about the system dynamics.