The Research in Toolpath Generation Method for High Speed Machining of Pocket
|School||Shanghai Jiaotong University|
|Course||Mechanical and Electronic Engineering|
|Keywords||High Speed Machining Toolpath generation Level Set Method Spiral Trochoid|
In the High Speed Machining of pocket, continuous and smooth toolpath with an even cutting load will ensure a higher efficiency and precision. But the traditional zigzag and contour-offset toolpath cannot fulfill these requirements, so in this dissertation, we proposed a spiral toolpath based on the Level Set Method and developed the trochoid toolpath generation technology based on the Medial Axis Transform. And the two novel toolpath can ensure the tool an even cutting load and less retraction, which will extend the tool life and make the machining more efficient.Frist, we introduced the theory and technology of Level Set Method, including the level set formula and the signed distance function, the numerical solution of the Hamilton-Jacobi equation, reinitiation, and curvature flow technology.Then, we proposed the spiral toolpath generation method. This method was divided into two steps: contour-offset generation based on Level Set Method and path linking based on the diagonal curve between the neighbor offsets. The curvature flow technology was employed to smooth the contour-offset curves in the first stage. And three different algorithms were developed to shorten the linking time in the second stage.Since spiral toolpath shows inefficient while machining the elongate pocket, so trochoid toolpath was studied by many researchers. We developed a full procedure for torchoid toolpath generation, and also came up with a medial axis traversing method which solved the difficulty on the linkage of the largest inscribed circles in sequence.At last, a toolpath generation toolbox developed in MATLAB platform——ADToolpath was introduced. And the toolpath simulation was performed on the VERICUT software; the two novel toolpaths generated by the toolbox were verified and analyzed.