The Residual Height Tool’s Path Planning And Fitting Of Triangular Mesh Model

Triangular mesh surface model has the advantages of fast, flexible, topology adaptable and has simple structure of data, it also has a wide range of application in reverse engineering parts products at the same time. Study on tool path of triangular mesh model can realize the integration of CAE and CAM for curve processing with scattered data points, it is helpful to shorten the manufacturing cycle of parts. In order to improve the surface triangular mesh model’s machining precision and efficiency. This article is mainly based on fitting and trajectory planning of STL residue triangular mesh model, the residues tool path is generated on the triangular mesh surface model. Firstly the equidistant offset triangular mesh model is calculated accurately, then the smooth tool path of is generated by optimization of trajectory.The specific works of this paper are as follows:(1) Analyzing the STL triangular mesh model to generate equidistant offset model based on offset of the vertex normal vector. On the basis of reconstructing topological relationship of the STL triangular mesh model, combining with the interference judgment of tool to generate equidistant offset grid model of high precision without interference, this method is verified that it can obtain higher accuracy of equidistant offset model through the hemispheroid grid model.(2) Studying the method of calculating tool path of residual height based on the model of equidistant offset. Taking ball end for example, firstly through the maximum offset of the residual height and tool’s radius to get mesh in residual site surface grid and cutter locus, then calculating the residual points on residual mesh to fit the residual curve. Finally, the tooth path is generated on the surface by examples, analysis and comparison of machining precision and machining efficiency in and cutting plane method. The results show that residual track method can enhance the processing efficiency under the condition of guarantee the processing precision.(3) Studying the fitting method of discrete cutter locus for fitting in NURBS curve.Firstly, the flaws and redundant points in cutter locus are processed, then the smooth tool path is obtained by NURBS curve fitting based on moving least squares method. The precision of the fitted curve is verified by examples.(4) Verifying the equidistant residual height trajectory method in this paper can generate tool path in equidistant offset triangular mesh model without interference by simulation of machining.