| The controllable excitation linear synchronous motor does not require multi-point support by electromagnets during operation.It has the advantages of frictionless and wear-free,etc.,through the excitation current to control the vertical electromagnetic attraction,and the platform is suspended on the guide rail..It can meet the requirements of high-precision CNC machine tools for high positioning accuracy and high speed,and has a wide application prospect.In view of the non-linearity,strong coupling and susceptibility to external disturbances of the magnetic levitation system,it is necessary to find a suitable control strategy to improve the stability and control accuracy of the control system of the controllable excitation linear synchronous motor.This subject is funded by the National Natural Science Foundation of China: "Research on the Operation Mechanism and Control Strategy of Magnetically Levitated Feeding Platform for Controllable Excitation Linear Synchronous Motors(Project Approval Number: 51575363)",with the magnetically levitation feeding platform as the application background.Study the control problem of linear motor magnetic levitation system under the disturbance of external uncertainty.The main research contents of the article are as follows:(1)The operation mechanism of magnetic suspension system of linear synchronous motor is studied and the mathematical model is established.According to the structure of Magnetic feed platform driven by linear motor,the operation mechanism of horizontal direction and levitation direction is analyzed,the mathematical model is established,and the analytical expressions of electromagnetic thrust and magnetic levitation force are derived.Combined with the motion equation,the state space model of magnetic system is established.(2)A direct adaptive controller based on RBF neural network is designed.The error function is constructed by the tracking error of the levitation height and the variation of the error.The direct adaptive ideal controller is designed and approximated by RBF neural network;An adaptive law is designed to estimate the ideal weight of neural network.The quadratic Lyapunov function is constructed for the change rate of error function,and the stability of the system is proved by Lyapunov stability theory;The control system is simulated by MATLAB,and the steady-state and dynamic performance are compared with the adaptive fuzzy sliding mode controller and PID controller.(3)Hardware circuit and software design of magnetic levitation control system.Hardware circuit design includes main circuit,control circuit and detection circuit.The main circuit of bridge reversible PWM converter is designed.The average value of output voltage is changed by adjusting the duty cycle,and the excitation current is adjusted to change the magnetic levitation force.The design of DSP minimum system circuit based on TMS320F28335 is introduced,including the design of 3.3V and 1.9V dual power supply circuit,the design of reset circuit with manual reset terminal TPS3828-3.3,and the design of DSP standard interface JTAG interface circuit.The design of sampling circuit includes position sampling and current sampling.Software design includes main program design and interrupt service subprogram design.The main program realizes the initialization of DSP system and the call and cycle of interrupt service subroutine.Interrupt service subroutine realizes signal sampling,A/D conversion,control algorithm realization and PWM control signal generation.The experimental platform of magnetic levitation system of linear synchronous motor is established,and part of the experimental research on magnetic levitation control system is carried out. |
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