Research And Application Of Digital Assembly Process Planning System For Rocket Engine

The assembly process planning of large and complex aerospace product such as rockets engine is a difficult task. Conventional task of assembly process planning accomplished by the salted process designer according the 2D drawing manually and CAAPP at present both have their own defections respectively in this field. On the other hand, digital assembly process planning provides an improved, cost-effective and high responsibility method to overcome such existing problems. This paper studies digital assembly process planning method and its key technologies orienting to rockets engine etc, which has important theorical and pratical values. It mainly includes:The architecture and workflow of digital assembly process planning system is proposed, and its key technologies are maken sure, according its requirement analysis.Product assembly modeling in digital assembly process planning is studied. After analyzing the basic requirements of assembly information model, and drawing lessons from current models, a hierarchically constraints-based assembly information model is proposed, which includes product layer, subassembly layer, part layer and feature layer, and the constraint relationships in these layers.Moreover, the basic distilling arithmetic and its flowchart are put forward. At last, the arithmetic program is realized in Solidworks basing on the Solidworks API. Assembly sequence planning is mainly studied. After absolute constraints set and evaluation set are established to express all constraints and evaluations in assembly, an improved genetic algorithm led by guided search is applied to generate initial optimized assembly sequence rapidly, which is proved effective, superior and available by a case. Besides, assembly path planning and assembly movie recording are implemented.The post-processing of assembly process documents and assembly operation training are studied. The method of organizing assembly process imformation by editing procedures and steps is studied, and then the assembly process tree is obtained. A method based on XML technology is applied to design, generate and output assembly process cards, and a web-based assembly training system is realized for assembly traning.Based on the above research work, the paper develops a digital assembly process planning system EDAPPS(Engine Digital Assembly Process Planning System) oriented to rockets engine, which has been applied in a workshop to guide the assembly process of aerospace product initially.