Robust H∞ control in nano-positioning

This paper considers the use of robust H^∞ tracking control in a nano-positioning system. The design of the controller takes into account of the existence of hysteresis in the piezoelectric actuator. Parameters in a nonlinear model of the system are obtained from experimental measurements. Experimental results show that the robust H^∞ controller yields accurate tracking of displacement and also significantly reduces the hysteresis.