High-bandwidth tracking control of piezo-actuated nanopositioning stages using closed-loop input shaper

An integrated control strategy for piezo-actuated nanopositioning stages is proposed in this paper. The aim is to achieve high-speed and high-precision tracking control of nanopositioning stages. For this purpose, a direct inverse compensation method is firstly applied to eliminate the hysteresis nonlinearity without involving inverse model calculation. Then, an inside-the-loop input shaper is designed to suppress the vibration of the compensated system. A Smith predictor is introduced to prevent the potential closed-loop instability caused by the time delay of the inside-the-loop input shaper. Finally, a high-gain feedback controller is employed to handle the disturbances and modeling errors. To demonstrate the effectiveness of the proposed control method, comparative experiments are carried out on a piezoelectric actuated stage. The results show that the proposed control approach increases the tracking bandwidth of the stage from 22.6 Hz to 510 Hz.