Robustness evaluation of new practical control for PTP positioning systems

This paper presents robustness evaluation of a new practical control for point-to-point (PTP) positioning systems. The proposed controller consists of a nominal characteristic trajectory as an intended motion trajectory and PI elements which are used to restrict the plant motion along the trajectory. The nominal characteristic trajectory is determined with measured open-loop responses of the plant and is also used to determine PI coefficients. Thus the proposed controller does not require an exact model of the plant and its parameters, and is easily applicable to practical systems. The robustness of the proposed controller is evaluated and compared experimentally with conventional PID controllers using an experimental rotary positioning system. It is proved that the proposed controller is better than the conventional PID controllers in robustness to parameter variation