Robust linear control of flexible joint robot systems

This paper presents the development and design of a robust linear controller for a flexible joint robot. First, a realistic model is developed taking into account the effects of stick-slip friction, nonlinear spring force characteristic, the rotors' Coriolis and centrifugal acceleration due to the velocities of the precedent links and rotors, and measurement noise. Second, a robust controller is designed using LQG/LTR techniques. Extensive simulation was performed on an experimental robot system using several trajectories. The results demonstrate that the proposed model/controller provides excellent tracking and regulation performance.