复杂三角网格模型分治加工刀具轨迹生成研究-机械制造及其自动化专业论文.docxVIP

华侨大学硕士学位论文 华侨大学硕士学位论文 Abstract Abstract 万方数据 万方数据 万方数据 万方数据 II Abstract In recent years, application of triangular mesh model is increasingly widespread. Moreover, the research on CNC machining for triangular mesh model has been growing to be concerned. However, researches on the tool path generation for triangular mesh model are insufficient, and tool paths on the model were mostly generated by a single method of tool path generation. That never meets the machining requirement of complex model. Therefore, the method of partition machining was presented to solve the contradiction between machining efficiency and accuracy in CNC machining of the complex triangular mesh model, which is composed of the segmentation of mesh model and tool paths generation of sub-regions. According to the research contents, the following research works are carried out in this paper. Firstly, to seek the adjacency of mesh elements (vertices, edges, facets) and calculate the amount of differential geometry of model quickly, topological structure of the triangular mesh model based on half-edge data structure was established. Moreover, the calculation methods of normal vector, curvature and dihedral angle for mesh model surface were introduced, and the selection method of neighbor point in R-radius was proposed. Secondly, triangular mesh model was divided into sub-regions for machining. In this step, the complex triangular mesh model was classified as model with clear boundary and model with unclear boundary. Then, growing principle based on dihedral angle was proposed for the region growing segmentation of model with clear boundary, and growing principle based on machining feature formulation was presented for model with unclear boundary. To avoid unnecessary short tool path, sub-regions were optimized, and their boundaries were smoothed. Finally, different tool path planning methods were adopted for different feature sub-regions. The tool path of flat feature surface was planned with iso-p