Robust Sliding Mode Based Impedance Control

The industrial robots are confronted with performing tasks where a contact with their environment occurs. Therefore, a need for control algorithms with position tracking performance and the force control ability appears. Up to date a lot of algorithms were proposed which deal with robot motion and force control. They could be mainly separated into two great classes, namely Hybrid control, where constrained and unconstrained DOFs of the robot are observed separately based on the principe of the ortoghonality, and Impedance control where the robot should adopt some physical properties such as mass, damping and stiffness in order to assure stable dynamic interaction with the environment. In this paper the robust impedance control law based on the attractive theory of sliding mode is proposed. The control law guarantees a robot predefined impedance and therefore force regulation based on possessed impedance properties is discussed. Experimental result on a simple 1 DOF mechanism is shown to verify theoretical statements.