Research On FTS Tracking Control Based On Voice Coil Motor

With the great progress of technology in the motor field,people turn their attention to the technology related to CNC machine tool manufacturing.Traditional processing methods such as grinding,polishing,etc were less efficient,and on the other hand,the accuracy was hardly to reach the demand.Diamond ultra-precision machining has the advantages of high precision,high efficiency and low cost.At the same time,this precision machining method has played an irreplaceable role in automobile,aerospace,military,medicine and other fields.With the advantage of high precision,fast tool servo plays a very important role.In this thesis,the fast tool servo system driven by a voice coil linear motor was studied,and the system was controlled by methods such as sliding mode control and active disturbance rejection control controled to the motor to achieve ideal tracking and disturbance suppression.The specific contents are as follows:First of all,the domestic and foreign references about the fast tool servo system were read and classified,and the drive mode,corresponding characteristics,and application fields of the fast tool servo system were mastered.According to the structure and working principle of the actuating device,a mathematical model was established to facilitate simulation building,and the control strategies and the main factors affecting the control accuracy of the system were analyzed in depth.Secondly,for the fast tool servo system studied in this thesis,the driver was selected as a voice coil linear motor.Based on the mathematical model of the motor,the corresponding integral sliding mode control law was designed.At the same time,for the problems of jitter vibration,high frequency noise emitted by the motor,the accuracy does not meet the requirements,and no filtering effect of the sliding mode control,the active disturbance rejection control controller was designed to combined with the sliding mode control to reduce the negative impact of disturbance on the system by using the filtering capability and the expansion state observer to enhance the immunity of the system and reduce the gain of the system.Finally,an exponentially convergent disturbance observer based on the disturbances that exist during the operation of the system,such as cutting forces and external vibrations,was designed,and the compensation effect of the sliding mode control was used to suppress the disturbances.The adaptive sliding mode control controller was also designed and combined with the expansion state observer in Chapter 3,which combined the advantages of both adaptive control and sliding mode control,allowing the system to maintain a high performance.Finally,the proposed composite control strategy was simulated in Matlab/Simulink to verify the tracking performance of the system and the suppression capability of the disturbance observer on the disturbance.