Research On Servo System Of CNC Machine Tool Based On Variable Universe Fuzzy PID Control

With the constant development of power electronics, control theory and micro-processing technologies and other related technologies the performance of the servosystem is continuously improving, and the servo system has been widely used invarious fields. In recent years, great progress in the servo system research have beenmade, however, there is still a long distance compared with the foreign. Theperformance of domestic servo system is not excellent, which is mainlyconcentrated in the low-end applications, while high-precision servo system mostlyrelies on foreign imports. Therefore, research on the related technology of the servosystem is of great significance.This subject is mainly about the issues that the universities is short of servosystem experimental platform, the control procedures of some servo experimentalplatform is opaque, and the control algorithm is difficult for secondary development.To teach and research, some research and design have been done about the servosystem and its position control loop in the paper, the main work is as follows:Build an open three-axis servo experimental platform.Three kinds of servosystem theory are introduced in detail in this paper, taking the most appropriatewiring on the experimental platform. The experimental platform takes the localcomputer as a PC, utilizing advantech data acquisition card PCI-1711based on PCIbus to achieve real-time data collection, using Matlab real-time data acquisitionmodules RTWT, automatic code generation module RTW and its powerful datacomputing function to achieve real-time control of the servo system position loop.Research and design the control algorithms of servo system position loop.Based on the servo platform, variable universe fuzzy PID control algorithm hasbeen researched in this paper. Because that position servo system is verycomplex,and it is a nonlinear time-varying system, the traditional PID control can’tmake the servo system achieve better performance. The servo performance of theservo system is improved mainly by adding advanced control methods on theposition loop. This paper starts from control algorithms, combining the fuzzycontrol and traditional PID control, designing the fuzzy PI controller. For the issuethat the controller universe is hard to select when the input error range varies, thefuzzy PI controller is added to the variable universe section. The basic universe offuzzy controller in real time is adjusted according to the input error and error rate ofchange,and fuzzy rules of fuzzy control are fully utilized. This text makes adetailed presentation of the controller design process, and verifies the superiority ofthe control algorithm by simulation. Finally, the variable universe fuzzy PI control algorithm has been verified onthe servo experimental platform built in this paper. Through experimentalwaveforms, the better control performance of variable universe fuzzy PI controllerhas been proved. In the end, two-axis motion of the X-axis and Y-axis of the servosystem has been achieved by applying interpolation algorithm.