Research On Fuzzy Sliding Mode Control Of Magnetic Levitation System Of Controllable Excitation Linear Synchronous Motor

Aiming at the problem that the Controllable Excitation Linear Synchronous Motor's(CELSM)magnetic levitation feeding platform is susceptible to load changes and various disturbances during operation,this paper designs a magnetic levitation control system to realize the reliable control of the levitation of the motor's moving platform.Specific research contents are as follows.The working principle of the motor is analyzed.The analytical expressions of voltage,flux,electromagnetic thrust and magnetic levitation force of the motor in different coordinate systems are derived,and the motion equations of levitation direction and horizontal direction are further derived.According to the mathematical expression of the force,the coupling problem between the magnetic levitation system and the feed system is analyzed,and the partial decoupling of the two systems is realized by using the method that the armature current q-axis component is zero.The expressions of electromagnetic thrust and magnetic levitation force after partial decoupling are derived.The block diagram of the motor control system with decoupling of the two systems is built to reduce the mutual interference between the control systems and simplify the design of the position controller in the magnetic levitation control system.A fuzzy sliding mode controller for magnetic levitation system is designed.This paper deals with the problem that motor movement platform is susceptible to load changes and external disturbances.The sliding mode controller is designed to reduce the influence of disturbance on magnetic levitation system.In order to reduce the chattering of the magnetic levitation air gap height and improve the anti-disturbance performance of the motor,the designed sliding mode controller is modified,and the fuzzy system is introduced under the premise of retaining the anti-interference ability of sliding mode control,so as to further design the fuzzy sliding mode controller.Using the estimation characteristics of the fuzzy system to estimate the gain in the switching term in real time,and replacing the fixed gain value of the constant velocity approach law with the estimated value,the speed of the state variable when it passes through the hyperplane can be effectively reduced,and the chattering of the air gap height and the excitation current of the magnetic levitation system can besuppressed.The response curve is analyzed to verify that the response performance of the magnetic levitation control system is superior to other magnetic levitation control systems.An adaptive fuzzy sliding mode controller for magnetic levitation system is designed.In order to suppress the disturbance of uncertain disturbance to the moving platform and reduce the chattering of the system's air gap height and avoid the failure of fuzzy sliding mode control due to the limited number of rules and the lack of self-adjustment ability,an adaptive fuzzy sliding mode controller is designed.In order to reduce the chattering and error of the height and current and improve the operation efficiency of the motor,a switching function including the integration of state variables and a piecewise approach law for automatic speed adjustment are constructed.The adaptive fuzzy system is used to estimate the total disturbance of the levitation direction,and the adaptive fuzzy sliding mode controller is obtained by introducing the disturbance estimate value into the controller to reduce the disturbance to the levitation height of the motor.The energy function is constructed to verify that the adaptive fuzzy sliding mode control algorithm can make the system converge.The control system simulation block diagram is established,and the simulation results are analyzed.