Research On Control Strategy And Drive Of The Permanent Magnet Synchronous Linear Motor

Permanent magnet synchronous linear motor(PMSLM) compared to the rotary motor has many advantages such as high-speed, high-precision, high-thrust, direct drive and so on. It has broad application prospects in semiconductor manufacturing, precision CNC machine tools, printing equipment and many other areas. However, because of the structural characteristics of the linear motor and using the "zero transmission" drive way, the thrust ripple caused by load disturbances, system parameter perturbation, positioning force and other disturbance factors will directly affect the stability of low speed and positioning accuracy of the servo system, severely limiting its widespread use in the industrial practice. Therefore, from the view of control point, the problem of how to improve the robustness of the linear motor servo system is studied, and verify it by experiments.At first, this paper analyzes the basic structure of the permanent magnet synchronous linear motor and its works principle. Then, using the idea of coordinate transformation, the mathematical model of linear motor is established in synchronous rotating coordinate system(dq coordinate system). Introducing the vector control theory, analyze and determine to use the id= 0 control strategy, and on this basis, elaborate the voltage space vector pulse width (SVPWM) control technology. Based on analyzing the structure of linear servo three loop control system from inside loop to outside loop, propose a permanent magnet synchronous linear motor speed control strategy. In the design of the speed controller, use the sliding-neural network two degrees freedom controller to replace the traditional single degree freedom PI controller. Sliding mode controller makes the system fast and has good dynamic tracking performance; using BP neural network controller as an output feedback controller for the system, effectively suppress the parameter perturbation, external resistance and other uncertainties, at the same time weaken the system chattering caused by sliding mode control, improving the robustness of the system. Meanwhile, against the thrust ripple caused by permanent magnet synchronous linear motor positioning force, this paper presents a thrust ripple suppression strategy based on BP neural network. Designing a BP neural network force ripple observer can effectively restrain the thrust ripple, reduce the interference source and further reducing the system chattering, improving the system performance. Use simulation software Matlab verify the above theory.At last, based on TMS320F2812’s DSP/BIOS, introduce the design method and the implementation method of permanent magnet synchronous linear motor servo control hardware and software system in detail. Build a control system and conduct experiments debugging and experiments assess. The experimental results demonstrate the effectiveness of the control strategy, laying the foundation for further system optimization, improving control algorithms and other works.