Damping Control of Piezo-Actuated Nanopositioning Stages With Recursive Delayed Position Feedback

This paper presents a new damping control scheme for piezo-actuated nanopositioning stages with recursive delayed position feedback (RDPF). The RDPF is proposed to attenuate the resonant mode of the nanopositioning stage in the inner feedback loop, which results in a neutral-type time-delay system. To realize the pole placement of this system, a new numerical integration method is proposed to determine the rightmost pole and select the parameters of the RDPF. Then, a high-gain proportional-integral (PI) controller is designed in the outer loop to minimize the tracking errors caused by the hysteresis nonlinearity and modeling uncertainties. To validate the effectiveness of the proposed approach, comparative experiments are conducted on a piezo-actuated nanopositioning stage. Experimental results demonstrate that the proposed approach improves the control bandwidth of the system from 32.5 Hz (with the PI controller) and 687 Hz (with the conventional delayed position feedback based controller) to 793 Hz.