Research On Modeling And Motion Control Of Moving-coil Magnetically Levitated Permanent Magnet Planar Motor

Magnetically levitated permanent magnet planar Motor(MLPMPM)is a new planar motion mechanism,and the mover is levitated above the stator and realizes the large stroke plane motion.Since there is no mechanical contact,MLPMPM has a series of characteristics,such as simple structure,no friction and wear,light movement weight.MLPMPM is the core drive components of the novel high performance lithography machine and the next generation of extreme ultraviolet lithography.A multi freedom degree magnetic levitation planar motor is discussed in the dissertation,and we focus on the levitation control technique and planar positioning control technique.In-depth research on the dynamics of planar motor modeling,coupling analysis,robust decoupling controller strategy,control system integration and a series of problems are made.The following results have been achieved:Firstly,based on the first fundamental model of the permanent magnet arry’s magnetic flux density distribution with the simplified coil model,the mathematical model of single coil thrust/torque is studied by using the Lorentz Force Law.According to the desired thrust/torque,a new current distribution strategy was proposed to realize the decoupling of the thrust/torque of the moving coils.Based on the current allocation strategy,the thrusts along the x and z axis direction are analyzed in Maxwell 3D finite element simulation software when the mover deflecting through small angles.It lays the foundation for 3-DOF control of the motor.Secondly,due to the decrease of electromagnetic force caused by the deflection of the mover or the sharp decrease of magnetic flux density with height,the 3-DOF control system of moving-coil MLPMPM is established using ADRC scheme.The control model is built in Matlab/Simulink environment.The motion simulation of horizontal and vertical direction is carried out in the case of sudden load and disturbances.At the same time,the estimation effect of ESO module for the comprehensive disturbance is analyzed.At last,the realizability of system is proved.Finally,the experimental platform is built by using industrial computer,DAQ card,current converter,position sensor,plane motor and experimental prototype.The sudden load disturbance along the x-axis horizontal direction and the z-axis vertical direction of the motor are experimentally verified,and compared with the simulation results.The experimental result proves the effectiveness of the control system.In summary,the proposed current decoupling strategy and the 3-DOF positioning control system can achieve the high precision and high speed positioning for the moving-coil MLPMPM.Its effectiveness can be proved by the magnetic levitation experiment platform.The research achievement has a certain theoretical significance and practical value for the further development of high precision and large stroke plane positioning device.