| With the increasing demands on the CNC machining technology for high speed, ultra-high speed, precision and ultra precision, zero transmission, the linear servo feeding system with highly responsive capability has come into being, and linear drive technology has found wide application in the field of precision positioning. Compared with the traditional feeding of "rotary motor plus ball screw", the linear motor servo feeding system is more difficult to control, while eliminating some adverse effects caused by the mechanical transmission chain. High-precision micro-feed might cause more uncertainty like perturbation and disturbance directly affecting the feeding motion, which is also an inevitable result of zero transmission control. Therefore, we need to find an effective control strategy to meet the demands for high precision and high speed in processing.This thesis analyzes the specific characteristics of linear motors and the actual implementation of vector control principle on the basis of previous experience and research. A vector control model of permanent magnet linear synchronous motor is constructed based on MATLAB/ Simulink, and a concrete model is provided here for the implementation of different controlling strategies as well as a reference for further research in the future. In the meantime, the traditional PID control strategy is analyzed here, because, despite its simplicity of algorithm, high robustness and reliability, the conventional PID controller can hardly achieve the desired control effects due to such factors as nonlinearity, strong coupling, long-time variation and uncertain load disturbances of linear AC servo motors. Aiming at these features, a self-tuning fuzzy controller is designed based on fuzzy control theory and the quantitative factors are optimized with the genetic algorithm. Finally, a simulation model is established under Matlab/ Simulink. The research indicates good control effects through simulation by presetting the parameters. |
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