Retarded Control Method And Experiments On Magnet-Driven Nanopositioning Stage

Nanopositioning stage is widely used in microelectronic manufacturing,precision measurements and micro/nano machining.The performance requirements of positioning stage in precision measurements and machining are higher and higher,and reach nano-scale resolution as well as longer stroke.Traditional piezo-actuated positioning stages have very high precision,but the moving range is limited within micrometers.Though additional structure or macro-level actuators can extend the range,it is very hard to design mechanisms and control.In order to solve above problems,this paper designs and builds electric-magnet driven planar nanopositioning stage and hardware-in-loop(HIL)system,and presents quick positioning retarded controller.Firstly,design the mechanical structure of positioning stage and actuators according to the performance indicators.Use air bearings to support the moving platform.Drive with 3 linear actuators in a plane.Choose planar grating encoder as position sensor.Secondly,design electric circuits for driving signals,feedback signals and communicational signals for power board,convertor board and data acquisition board as hardware of control system.Program drivers for read modules,communicational protocols and DMA modules.Construct HIL system based on Simulink Real-Time toolbox in MATLAB.Presents retarded controller on electricmagnet actuators,and compares with PI controller and PIDN controller.Analyze stability of retarded controller with direct integral method(DIM).Apply differential evolution algorithm to optimize parameters of controllers.Finally,decouple forces of planar 3-DOF stage and control with retarded controller.3-order trajectory plan is designed for point-topoint motion.Verify resolution and range of the stage.