Development Of Precision Air-Bearing Turntable Control System For Micro-Nano CT

Precision turntable is an electromechanical device which integrates optoelectronics and electromechanics.It plays an important role in numerous fields;for instance,optical precision detection and nanometer device manufacturing.The servo driving control technology is one of the most important technologies to realize the function of turntable.Consequently,the research on the control technology of precision turntable has extremely important theoretical and application significance.Taking the micro-nano CT ultra-precision turntable as the control object.The subject researches the servo drive control system of the precision air-bearing turntable manufactured by the ICT Research Center of Chongqing University.The paper will focus on the needs of actual project.The main contents in this paper are as follows:(1)It analysis the structure characteristics of precision air-bearing turntable for micro-nano CT,and states compositions and working principle of servo control system of the turntable in detail from the mechanical structure and driving control system.In addition,the selection of servo control system is completed,and the overall control strategy is designed.(2)Based on the permanent magnet brushless direct drive torque motor,which is the driving part of the turntable.The mathematical model of the controlled object is established by using the equation of electromagnetics and dynamics.And different control algorithms(PID,Fuzzy-PID)are selected to design the controller of the closed-loop for the servo control system in detail.At the same time,the simulation of the control system is carried out in MATLAB/Simulink,which verifies the effectiveness of various algorithms.(3)The hardware and software of the servo drive control system is developed,including the core circuit of the control system,the power amplifier circuit,the phase current detection circuit,the circuit of detection and protection,communication,LDO power circuit of the control system and the monitoring software,lower computer control algorithm,the control strategy program,service and interruption subroutine of the servo system.(4)The experimental platform is set up and the servo drive control experiment is experimentally studied,which verifies the correctness of the design of hardware system and software.The experimental results indicate that the developed system can realize the speed and position control of precision turntable,and has good follow-up.