Robust motion control of mechanical systems with compliance

Modeling and effects of coupling compliance of mechanical systems in high performance motion control systems and robust control of a simple model of such systems, a two inertia system with a compliant coupling, are addressed. Two optimal control approaches, a frequency shaped linear quadratic regulating control and a linear quadratic tracking control with observed disturbance compensation, are presented. Frequency shaped weighting functions are used to suppress the vibration caused by the higher order unmodelled dynamics. A disturbance observer is proposed to estimate the disturbance entering the system through a different channel, from that of the control input. This makes it possible to design a state observer using the Kalman filter technique. Simulation results show that both of the two optimal control approaches both have better performance than selected existing control schemes