Research On Tread Pattern Hierarchical Modeling And Its CAD System Based On Reverse Engineering

Because of the complexity of the tire pattern structure and the existence of micro features, such as grooves, cracks etc, there often exists a certain amount of deviations between the molding pattern and the design pattern in the tire curing process, which lead to distortions on the performance analysis of tire pattern noise, water skiing, grip as well as other aspects. To solve this problem, this thesis focuses on the key technology of tread pattern hierarchical modeling and its CAD system based on reverse engineering, so as to build the semantic rules library for tread patterns and the semantic model library for tires, which could be used to guide the pattern design, analyze the performance of decorative pattern and optimize the process. Specific researches are as follows:(1) The key technology of reverse engineering is analyzed. Summarize the technologies in detail, attempt and compare their application to the tire point cloud data.(2) Characteristics and modeling of tire pattern are studied. Integrate pattern positive design process, split and design the pattern, on this basis, a method of tread pattern hierarchical modeling is proposed.(3) Tire point cloud data pretreatment is studied. Combining with the space segmentation scheme of sphere mixed with sector, project 3D scanning cloud points into a tread gray image with depth referenced by the principle of layering slicing, to bypass the data missing problem at micro characteristics by scanning accuracy.(4) Tire tread pattern border feature extraction is studied. Referring to the method of projection image feature extraction, an algorithm of feature extraction is proposed integrated the regularity of pattern border region growing, which is on the basis of translating depth image into gray image.(5) The technology of tire tread curve approximation and reconstruction is studied. The approximation of pattern curve mixed with straight lines and arcs in tangent continuity is realized based on the definition of best uniform approximation.(6) The system of tire reverse hierarchical intelligent modeling is developed. With CATIA V5 as a design platform, we developed a research and development platform integrated design, analysis and management.