Robuste Regelung eines nicht-holonomen, unteraktuierten SCARA roboters

This paper presents a control strategy for robust stabilization of a non-holonomic underactuated SCARA robot with 2 degrees-of-freedom. The first joint of the robot is actuated by a direct-drive motor whereas the second joint is equipped with a brake. A control law is derived, using non-collocated linearization (NCL) and a PDcontroller. By use of a Lyapunov-function the stability of the NCL-PD-controlled and parameter disturbed system is examined and a stability region is derived. Based on this stability region and appropriate switching of the holding brake an extended control strategy is developed. It is shown that global and robust asymptotic stability can be achieved. Experimental results confirm the efficiency of the proposed approach for global stabilization of the non-actuated joint.