| The controllable excitation magnetic suspension linear synchronous motor is applied to the machine feed platform,which can simultaneously realize suspension of the feed platform in the vertical direction and directly drive in the feed direction,there by eliminating the friction caused by the direct contact between the feed platform and the stationary guide rail and the adverse effects caused by traditional mechanical drive chains.The suspension system of the magnetic suspension feed platform has the characteristics that is difficult to establish the accurate mathematical model,the coupling between the feed system and the suspension system is strong,time-varying,nonlinear,and the external disturbance is caused by the reason that the transmission is deleted and acted on the motor,seriously affecting the performance of the magnetic suspension system.In view of the above problems,variable universe fuzzy PID control is applied to the magnetic suspension linear synchronous motor,and the desired control performance can be obtained.The main research contents of this topic are as follows:(1)Establishment of a mathematical model of the magnetic suspension system.The structure of the magnetic suspension feed platform is analyzed.The magnetic suspension operation mechanism of the magnetic suspension linear synchronous motor is studied and the vector control mode of the motor is proposed.The voltage equation and flux linkage equation of the magnetic suspension linear synchronous motor are given.The mathematical model of the motor under the dq axis system is established,and the suspension force characteristics are analyzed.Finally,the state equation of the magnetic suspension system is derived.(2)Variable universe fuzzy PID controller design for magnetic suspension linear synchronous motor magnetic levitation system.The fuzzy parameter self-tuning unit is designed to adjust the parameters of the PID controller when the error and error rate change,and the controller has good real-time performance.In order to obtain more accurate numerical value of PID parameter adjustment,the variable universe module is added on the fuzzy parameter self-tuning unit,so that the fuzzy universe can be adjusted when the errors is difference,and the controller can use more targeted fuzzy rules.And study the influence of the internal parameters of the scaling factor on the control performance.The simulation results show that the controller can make the suspension system follow the given signal well,strong robustness and good adaptability,which can effectively refrain the interference signal.(3)Design of magnetic suspension control system for magnetic suspension linear synchronous motor.Design the hardware circuit of the control system,including the main control system circuit,MOSFET drive circuit,current detection circuit,suspension height detection circuit and protection circuit;the control software part includes the main program and the interrupt service program,and the interrupt service program includes the variable universe fuzzy PID control algorithms,current and supension height signal sampling,generating PWM and more. |
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