Abstract:

A method for 3D model retrieval of mechanical parts based on skeleton tree is put forward. Retrieval is divided into two stages. The first stage is to extract the 3D model skeleton of mechanical parts, and then convert the skeleton into a skeleton tree. Using the adjacency matrix to describe the topological structure of the skeleton tree, the initial selection of mechanical parts is realized by comparing the sum of eigenvalues of the adjacent matrix. A large number of models which have a big difference with the matching model in topological structure are filtered out, which greatly reduces the matching computation of the second stage. The second stage, find the matched skeleton subtree firstly, search matched skeleton branches based on the matched subtree secondly, and then using the curvature and Frenet frame of space discrete curves to calculate the skeleton branches similarity, and then get the whole skeleton tree shape similarity. Through example analysis with the experiment, this method is effective and has high accuracy and good robustness.

Key words: 3D model retrieval, adjacent matrix, Frenet frame, skeleton tree, topological structure, mechanical parts