Secondary Development of CAD Software for the Construction of Mechanical Product Design System

Abstract

To meet the needs of different stages of product generalized design process, presents a CAD software secondary development method for the construction of mechanical product design system. Firstly, a freehand drawing board based on CAD geometric modeling platform is used to draw three-view sketches. Then, feature information was extracted from the freehand three-view sketch and the three-view projection from CAD models in the model library, and 2.5D spherical harmonic descriptor was used to represent the feature information of the sketch. Finally, Euclidean distance was used to calculate the distance between graphic feature vectors obtained by spherical harmonic transformation, so as to realize the similarity evaluation between models, and the algorithm was verified in the agricultural machinery and equipment model base. The experimental results show that the feature extraction time and feature comparison time of the proposed algorithm are only 0.471s, while the processing time of the other two algorithms are 0.937 and 0.826 respectively. The product designed by this system has better retrieval performance, and the retrieval results can better reflect the user's retrieval intention. It can save design time and improve production efficiency of products, and has high practical application value.