Tracking Control Of Slow Tool Servo System Based On Repetitive Control

Since the 1950 s and 1960 s,with the continuous development of optoelectronic technology in civil and national defense scientific research,traditional simple optical elements with single function can not keep up with the needs of production and living.At this time,complex optical surface elements with rich functions gradually appear.Slow tool servo is an efficient processing platform for complex optical surface elements,It uses solid diamond tools to precisely process optical components.It has the advantages of large stroke,high machining precision and convenient operation.In order to improve the machining accuracy of the slow tool servo system,this thesis takes the feed Z axis where the slow tool servo system processes the tool as the research object,studies the tracking accuracy of the feed Z axis and the control method to suppress the disturbance.The specific research contents are as follows:Firstly,by collecting and viewing the research status and relevant data of the slow tool servo system at domestic and aboard,have a deep understanding of the structure and principle of the processing machine tool of the slow tool servo system,classify the permanent magnet synchronous linear motor,select the ironless permanent magnet synchronous linear motor as the system feed z-axis driving device,select the surface-mounted permanent magnet synchronous motor as the rotating C-axis drive device,analyze the advantages of the motors,and establish the motors mathematical model and friction model.Secondly,design the controller.In the process of machining,the slow tool servo system requires the system not only to have good tracking accuracy for periodic input commands,but also to have good suppression ability for periodic and aperiodic interference in machining.In view of the above problems,the improve repetitive control is designed to suppress periodic interference while tracking input signals.In order to suppress aperiodic load disturbance,it is combined with terminal sliding mode control,The fractional calculus operator is introduced to weaken the of sliding mode chattering,increase the adjustability of the system and improve the tracking accuracy of the system.Finally,the designed control algorithm is simulated in Matlab/Simulink and compared with the traditional terminal sliding mode repetitive control to verify the superiority of this method.Finally,the slow tool servo system belongs to the precision machining system.Any small errors can lead to the non-compliance of the machined parts.The load disturbance has a great impact on the machining accuracy.Now,a fractional order terminal sliding mode repetitive control based on the third-order extended state observer is designed to observe and compensate the unknown disturbances such as system modeling error and load disturbance in real time,and prove the observation stability of the third-order extended state observer,Finally,the control algorithm is simulated and verified in Matlab/Simulink.The fractional terminal sliding mode repetitive control is compared,and the excellent effect of the designed control algorithm is compared and analyzed.