Research On Dynamic Control Technology Of Magnetic Levitation Positioning Platform

With the rapid development of IC manufacturing and high-speed and high-precision machining,the stroke,speed,acceleration and accuracy of the positioning system are put forward higher and higher requirements.The traditional precision positioning movement platform has been unable to meet the demand.In order to further improve the accuracy of positioning platform,this paper uses the suspension technology and linear drive technology to replace the traditional institutions designing the magnetic levitation positioning platform.This paper focus on the structure,magnetic field design and control methods to optimize the movement performance of the magnetic levitation positioning platform to achieve high-precision positioning.Aiming at the complex electromechanical coupling characteristics of the magnetic levitation positioning platform,the geometrical parameters of the positioning platform are optimized by optimizing the thrust,thrust fluctuation,normal force and cogging force of the positioning platform from the viewpoint of magnetic field optimization..Based on the design and optimization of magnetic levitation positioning platform,the mathematical model of single degree of freedom and three degrees of freedom will be established which will reduce the difficulty of the control system.Aiming at the high precision positioning of the magnetic levitation positioning platform,different decoupling control algorithms are proposed for different models based on the dynamic decoupling in the suspension direction and the horizontal driving direction.For the single degree of freedom in the direction of suspension,design incomplete differential PID control algorithm.For the three degrees of freedom in the horizontal drive direction,design Sliding Mode Variable Structure Control Algorithm based on the index approaching rate.For uniaxial synchronization error,design sliding mode variable structure synchronization controller.These control methods are designed to improve the positioning accuracy of the magnetic levitation positioning platform,and do research on the dynamic tracking response simulation.On this basis,to build a magnetic levitation positioning platform control system based on the master chip of TMS320F28335.The hardware circuit design scheme including current sampling circuit,off-chip ADC module,laser displacement sensor module,IPM intelligent power module and fault detection circuit module is given.This paper analyzes the control strategy of the software,such as the initial zeroing position of the positioning platform,the interruption of the stable suspension,the interruption of the XY plane displacement,and the software link based on the exponential approximation rate and completes the construction of the magnetic levitation positioning platform experimental system.Finally,based on the experimental system of magnetic levitation positioning platform,the localization accuracy is studied and verified to meet the design index of this paper.Through the collection and analysis of experimental data,it is proved that the magnetic levitation positioning platform based on the control system can achieve high precision positioning.