On a novel magnet-driven linear actuator with long stroke and nano-positioning accuracy

Abstract

The nano-positioning system with long stroke is the key component of the micrometer and nanometer manufacturing and measurement devices, such as atomic force microscope (AFM), laser direct writing, nano-machining, lithography etc. In this paper a novel linear magnet-driven actuator is proposed. The Halbach magnetic array with air bearings is adopted as the mover. The winding of stator is ironless structure. The actuator has a nanometer scale positioning resolution. The designed stroke is 50 millimeter. The high-accuracy optical incremental encoder and subdividing system are employed to measure the motion of the mover, facilitating real-time feedback control. The hardwarein- loop simulation system of the actuator is set up based on XPC-target module in Matlab/Simulink toolbox. The parameter identification and Simulink control model of the actuator are implemented. Finally, the trial test and analysis are carried out. The results show the presented actuator could be operated with the positioning resolution of 9.5 nm root mean square (RMS).