Permanent Magnet Synchronous Motor Control Strategy Research And Cnc Machine Tool Servo System Optimization

As an important part of CNC machine tools, servo system directly determines thequality of machining performance. Permanent magnet synchronous motor servo systemis a high-performance servo system that commonly used in CNC machine tools. Thecore of the servo system is to control motor speed and torque (current) via the servodriver, and torque control is more important. In order to gain insight into and master themachine tools servo drive methods, and provide methodological basis for the control ofdirect drive permanent magnet linear motors and torque motors, etc., permanent magnetsynchronous motor servo drive system control strategies and methods widely used sofar are studied in the article. In the establishment of permanent magnet synchronousmotor dynamic mathematical model, the principles and characteristics of the vectorcontrol method which is a commonly adopted servo control way, are detailed analyzed.The control mode of i d=0is analyzed via the Matlab simulation modeling method,and effectiveness of the control way is verified.There are few mature servo products based on using the direct torque controltechnology, and this control method is the one of the hot spot in the research of scholars.The direct torque control method is studied on the basis of in-depth principle analysis ofthe theory. In order to improve the problems exist in the conventional direct torquecontrol, such as the torque fluctuations and the inverter switching inconstant frequency,measures of using the zero vector and SVM techniques are proposed. For theSVM-DTC method, the calculation of torque angle change to consider the rotor locationangle changes or not in predict-flux estimation model may have an impact on systemperformance.The Matlab/Simulink simulation models of PMSM speed control systembased on these modified control methods are established. Simulation results demonstratethe prominent role of these control methods in reducing the torque ripple, and show thatcontrol effect to consider rotor angle change in predict-flux estimation model is betterthan those does not consider the rotor angle change in SVM-DTC.In the context of domestic servo products mostly relying on imports, the thesisfirstly researches and explores the servo optimization methods to improve the drive performance of machine tools. Based on a particular horizontal machining center, whichis driven by FANUC servo control system, we use FANUC servo system optimizationsoftware Servo-Guide and machine circular error measurement devices ball bar tomeasure changes in machine performance after servo parameters are adjusted. Analysisand summary works are engaged subsequently in getting a general servo optimizationway, so that we can provide a viable basis for the actual servo optimization work ofmachine tool plant.