The Design And Control Method Of Magnetic Levitation Stage System

Maglev technology has the advantages of no friction, no lubrication, no wear, no noise, long service life etc, so it is quite suitable for the precision machining below the micron level. However, as the strong nonlinear and strong electromechanical coupling characteristics of magnetic suspension, which will reduce the motion precision and robustness, the maglev system performance mainly depends on the quality of the control system. Magnetic levitation stage control system includes magnetic suspension actuator, maglev power amplifier and magnetic levitation controller; this work implements optimization analysis and realization of these links step by step:The first part is dedicated to analyzing the mechanics characteristic, electrical characteristics of the magnetic suspension actuator, and deducing the relevant characteristic equations. Based on the characteristics of maglev system, we optimize the value range of electromagnet coil turns and coil diameter using characteristic equations.Based on the analysis and comparison of the feedback signal types, modulation mode and current response speed of power amplifiers, we complete the design and debugging of the hardware and software of a digital power amplifier and carry out experiments to test the performance of the power amplifier. The experimental results show that digital power amplifier has an output with high precision and linearity, responses rapidly, and the current ripple is small.Besides, the interference observer control structure based on the is introduced to improve the performance of the magnetic flux-type power amplifier. According to the actual magnetic levitation system, a new disturbance observer structure is constructed using the multi-feedback observation. The simulation results show that the new type of disturbance observer can obviously reduce the flux output jitter of the maglev power amplifier and is more suitable for the application demand of flux-type power amplifier compared with ordinary disturbance observer control structure. Finally, in order to promote the adaptability to the nonlinear characteristics of magnetic levitation system, the type-two fuzzy adaptive control algorithm is used as a magnetic levitation controller. The algorithm using adaptive structure combined with type-two fuzzy algorithm to conduct optimal robust controller regression approximation to the control target. Simulation results show that the compound intelligent controller can get better non nonlinear magnetic adaption speed and control quality in maglev system compared with the fuzzy intelligent controller and linear controller.Through the design and research on power amplifier, controller and actuator, the response speed and robustness of the control system are enhanced, and a nonlinear adaptive control algorithm is presented for reducing output jitter and nonlinear degree. This work will contribute to the improvement of the magnetic levitation control system performance.