Control Analysis of Point-to-Point Positioning Based on Macro-Micro Stage

Abstract

Macro-micro stage can achieve large travel range and high precision positioning. The macro stage is driven by voice coil motor (VCM). The micro stage is actuated by the piezoelectric (PZT). The positioning theory of macro-micro stage is described. In this paper, the compensating method of point-to-point (PTP) positioning is divided into two types: compensation before steady state (CBS) and compensation after steady state (CAS). The different control strategies are applied to meet CAS and CBS. Because of the structure of macro-micro stage and the saturation of micro stage, switching control plays an important role in realizing high precision PTP motion. When the error of the macro stage is less than the threshold and also the system meets the switching conditions, the compensation signal is sent to the PZT control loop for high resolution compensation. Finally, the numerical simulation results show that the positioning accuracy of dual stage is higher than single macro stage and can reach nanometer scale.