Research On Precision Rotary Positioner Based On Stick-slip Driving

The nanomanipulation system is a kind of system which manipulates nanoscaleobjects or whose precision is nanometer level. Because of large chamber and real-timevisual feedback, the nanomanipulation system based on SEM gets extensive application.The precision positioner, whose performance determines the quality ofnanomanipulation, is a key part of nanomanipulation system. Stick-slip driving is a newdriving method which relies on friction and inertia, positioner based on this drivingmethod has good characteristics such as small size, simple structure and high resolution.Based on stick-slip, this article devises a rotary precision positioning system which canapply to nanomanipulation system in SEM.This article firstly designs structure of the precision rotary positioner, which usespiezoelectric ceramic as power and apply flexible hinge to turn linear displacement intorotation displacement. Besides, this positioner uses two springs to adjust friction force.The final design of the precision rotary positioner has the advantages of of smallvolume, light weight, good stability and360°infinite rotating etc..In order to simulate positioner’s movement and analyse various parameters’influences to the motion theoretically. This paper builds dynamic model for thepositioner. By contrast, LuGre friction model is used to describe friction in the dynamicmodel. Results of simulation for positioner by MATLAB/Simulink indicate that thedynamic model can reflect actual motion of the positioner nicely.For controlling the positioner’s motion accurately, this paper establish a controlsystem based on USB communication. By using VC++6.0,Keil uVision2and CCS4.0respectively, this paper designs Man-machine interface, USB firmware and DSPprogram. Meanwhile, Digital-to-analog conversion module is maked. Ultimately, thepositioner can be controlled neatly through personal computer.In order to get the performance of the precision positioning system, this paperbuild corresponding experiments to test the signal generating system and positioner. Theresult indicates that the precision positioning system meets the design requirements.