Hardware Design Of Motion Control System For Magnetically Levitated Planar Motor

Magnetically levitated planar motor, which is a planar motion structure, is composed of astator and a translator. The translator of this planar motor is suspended above the stator withno support other than magnetic fields, and can realize large range planar motion. Because ofthe active magnetic bearing the translator can move in six degrees-of-freedom. Comparedwith the traditional stacked linear motors, this type of planar motors with simple structure,high speed and high precision can be used in ultra violet and extreme ultra violetsemiconductor lithography systems as one lynchpin of them.Study on this kind of motor isvery important and significative for promoting the technology of semiconductor lithographysystems with high performance.In this thesis, the motion control system hardware of magnetically levitated planar motorwas designed. According to the features of the motion control and coils current decouplingand control program requirements，the hardware structure of motion controller based onDSP+FPGA and power amplifier were designed.The hardware circuits on motion controllerwere designed such as: the subsystem circuits of DSP and FPGA, analog and digital I/Ointerface circuits, RS-485high-speed communication circuit, high-speed parallel bus interfacecircuits and power supply circuit. The hardware circuits on power amplifier were designedsuch as: interface circuit, PWM circuit, power bridge circuit, LPF circuit, current feedbackcircuit, and overload protection circuits. Finally the integrity and stability of motion controllerand power amplifier were verigied and tested on the system debugging platform.The motion control system hardware of magnetically levitated planar motor is open-ended,and the number of coils drived by the servo system can be expanded to32. Tests show that themotion controller and power amplifier can achieve good driving performance: the PWMswitching frequency can be up to100~200KHz, the driving current can be up to12A, thecurrent resolution is about5mA, the system’s responsive bandwith can achieve4KHz.