Point-to-point motion control for a high-acceleration positioning table via cascaded learning schemes

In this paper, effort is devoted to point-to-point motion control for the high-acceleration positioning table driven by linear motors. New performance indices for point-to-point motion are first introduced. Then, a cascaded controller is designed. It consists of an inner loop velocity PI controller and an outer loop position P plus A-type iterative learning controller. In the subsequence, the convergence analysis in both time and frequency domains is given. The control strategy has the property that only the position signal is required in the outer loop. With the common motion profiles, i.e., T-curve and S-curve, and partial knowledge of the system, point-to-point motion experiments are carried out. The maximum acceleration of the motion profile is 0.04 mm/ms(2) (about 4.07 g), and the maximum velocity is 0.4 mm/ms. Experimental results illustrate that the proposed controller can greatly improve the performance, and the S-curve motion profile has advantages over the T-curve one.