Contour Error Estimation Of Free-form Path And The Compesation Algorithm Research

With the high-speed development of CNC technology, people have becomeincreasingly demanding of the contour accuracy of the product in modernmanufacturing systems. Therefore, it has great significance to reduce the the contourerror arising in the CNC machining process and enhance China’s CNC technology. Thisis the core values of this topic. There are two ways increaseing the tracking accuracy ofthe machining process and improveing the accuracy of the contour of its machiningprocess directly to improve the machining accuracy of the numerical control equipment.For the two methods mentioned previously, the former operation can not guarantee thatthe contour error can actually be reduced, whereas the latter is inhibited the contourerror generation fundamentally. Apparently，the more direct and effective way toimprove the contour accuracy of the CNC equipment processing is to inhibit directlycontour error.This thesis is based on the free curve interpolation technology to research thereason of the generating of the contour error in CNC machining, analyze the extractionand the approximate estimation model of the contour error and design the closed-loopcontour error controller to reduce this error and improve the processing accuracy. Themain research work of this thesis is focuses on the following aspects.The contour error estimation model have beene analysed and a contour error modelbased on the concept of the system error has been established. The work involved in thispaper are the extraction and the appropriate approximate calculation of the contour error,as well as the analyses of the contour error model about real-time, feasibility andefficiency, etc.For the factors that generate the contour error, sach as CNC system dynamiccharacteristics and the presence of unstable factors, to explore the stability controlsystem disturbance effects of possible factorss. The perturbation characteristics of thesefactors the dynamic characteristics of the machine dynamicshave been analysed. And itscorresponding mathematical model has been established.After the established of the CNC system dynamic model, a controller based onpassive analysis has been designed to reduce or eliminate non-linear disturbances andunpredictable interference of the contour error. And contour error model and controllerhas been simulated by the MATLAB software and experimental verification on thebench.