Research On Three-axis Servo System Of CNC Machine Tool Based On Repetitive Control

Although our country began with the introduction and absorption of foreigntechnology in the last century and a series of servo motor bodies and digital controlsystems are researched and developed independently, there is a certain gap betweenforeign countries and us. Performance of servo system has already affected thehealthy development of China’s machine tool industry. So the research on the relatedcontrol technology of machine tool servo system has important significance. And itcan be applied to other servo systems.The error of servo system is analyzed based on the model of servo system in thispaper. The seasibility of repetitive control used in the servo system is proved. Andthe parameters of DC servo system and PMSM servo system of the experimentalplatform is designed. The plug in repetitive controller is introduced in position loopto compensate error and the simulation is done.At present, general CNC machine tool servo sytem has advantages such as non-transparent procedures, long development cycyle. Computer with data acquisitioncard and Matlab software is used to realize CNC machine tool servo system controlplatform in this paper. The proposed algorithm can be verified quickly by theplatform. Transplantable C code can be generated by Matlab. The code can betransplanted in to DSP. Therefore, the development cycyle is shortened.The control and detection of servo motor is realized by Matlab toolbox. Thus theservo system based on repetitive control is realized. The control parameter areoptimized through debugging. The single axis servo system performace achieves thedesired performance. The change of system performance is studied before and afterthe application of repetitive controller through experiment. The influence on thesystem by different repetitive controller parameters are also studied. Experimentalresults show that the proposed method eliminates the phase lag of position outputcompared with traditional PID control method. The servo system has high dynamicproformance and good steady accuracy.Finally the periodic motion of three axis servo system is realized with themethod of repetitive control. The experimental results show that the proposed systemwith repetitive contrl can suppress the periodic disturbance. The motion trackrealized by repetitive contrl has a high precision. The application of repetitive controlin the servo system has certain research value.