| Ultra-precision manufacturing field such as microelectronics processing is developing in a very small, very precise direction, requiring a super-clean, high-speed precision positioning platform. Magnetic levitation platform integrated the technology of electromagnetic levitation and linear drive, with zero friction, zero transmission links and other notable features.Based on the magnetic levitation system as a research object, a planar magnetic levitation platform and electromagnet parameters are designed and the suspension control of the system is studied in this paper. Specific contents are as follows:(1) The electromagnetic and temperature characteristics of the platform are anslyzed. The lines and characteristics of magnetic force provided guidance for the magnet pole layout and found the weakness point of control system. Electromagnet heating situation is analyzed and the results show that parameters design is reasonable.(2) The decentralized control of magnetic levitation system is researched. Through optimization design of electromagnetic force, equivalent single degree of freedom model is established. After discussed the relationship between stiffness and damping and PID control parameters, dynamic control parameters and simulation results are obtained. Finally, an improved PID controller is designed.(3) The method of state feedback decoupling control and coordinate transform decoupling control are researched for the coupling characteristics of magnetic levitation system. For the former, a servo controller is designed for one of the translational degree based on constraints and a feedback decoupling controller for the other three degrees. For the latter, a dynamic coordinate transformation matrix is derived to establish a dynamic decoupling controller. Simulation results show that the latter controller can obtain a better overall performance.(4) Hardware and software platform of control system are built and experimental reasearch. An amplifier and software control flow are designed. Single degree of freedom suspension experiment results show that the control system is effective and more robust under improved PID controler. |
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