Fast Tool Path Generation Of Surface Machining Based On RE

In surface profile processing, the reverse engineering (RE) should be combined withcomputer aided manufacturing (CAM). A commonly used method is that the objectsurface needs to be digitized at first, then measurement points are processed, and the datastructure is rebuilded. Part surface is structured by measurement points, then connect theCAM system for processing. The process is cumbersome with poor stability in the dataprocessing. Surface reconstruction quality depends on the experience and subjectivejudgment of the researchers. It is hard to guarantee the precision, and hindered the buidingand development of RE/CAM integrated system.A curved surface processing method is proposed in this paper. According to themeasured data, the tool path could be generated directly without surface reconstruction.With this method, the cumbersome data processing is not required, and the disadvantagesof surface reconstructing process is avoided. Measurement and processing can be unifiedby using the same model.This paper is based on quadric surface, and the main characteristics of variousmethods is compared. Contact-type three coordinates measuring is selected to simulateanalytic surface,and the discrete data points are even and orderly. The micro plane andmicro spherical surface of radius compensation are compared juging by the error. Z-mapmodel is used to organize the data acquisition, the C type and R type data structure arecreated corresponding to measurement data. The update and contour line machiningstrategy of the date model which is based on Z-map are proposed. Double three B-spline isselected for discrete points differential geometry information. The tool path generationmethod of the target surface is based on the principle of equal residual height processing.At the same time of the tool path calculation, triangular patch is used to check theinterference and revise if necessary. Cutter axis vector is corrected for local angleinspection on cutting problem. The entire Z-map model in the direction shown by the Rdata index is traversed by the tangency curved surface and the main curvature of contactpoints, then the curved surface machining tool path is generated. The digital process on the surface and NC machining research has certain theoreticalsignificance and practical value. A reference could be provided to achieve RE and CAMintegration in this paper.