Research On Key Modeling Technologies For Aircraft Assembly Process Mock-up

There is a trend towards integration of aircraft design and manufacturing. Aviation industryenterprises urgently need to establish digital process information transfer system to improve transferefficiency of process information, which can meet the “low cost, short cycle, and good quality”demands of the aircraft manufacturing. In view of the practical problems and applicationrequirements of aviation enterprises, the modeling, representation, and transfer of processinformation are studied. Aircraft assembly process mock-up is defined, and its key modelingtechnologies are researched in depth. The creative achievements are as follows:(1) In the aircraft assembly process planning, a lot of process information is transferred todownstream phases. Through analyzing that process information, assembly process mock-up isdefined. According to the mock-up,3D model is a carrier, and assembly process structure is mastermodel, and the geometry and process attributes of all kinds of process information are modeling. Andthen the relationship between the geometric information and non-geometric information is established.The digital process information can be transferred smoothly and effectively to downstream phases.(2) In view of the nonlinear of aircraft assembly planning, hierarchical mixed assembly planningmodel is proposed to generate assembly process structure, which includes two key methods: anassembly unit partition method based on immune algorithm and a gradually solving method forassembly sequence planning. According to the assembly relation intensity matrix, immune clonealgorithm is applied to clustering optimization, and then all the assembly units are gotten. Accordingto the mixed code matrix of assembly constraints, all the feasibly assembly element of every step areregarded as evaluation object set in assembly process, and an evaluation model based on multi-factorfuzzy comprehensive evaluation is established, which aims to obtain the optimal assembly sequencegradually. The two methods co-operate with each other to generate assembly process structure, whichcan meet the engineering demands.(3) A hierarchical modeling method based on topology for process feature is proposed. Bottomframe of process feature model is constructed by using Polychromatic Sets. Reasoning matrix is usedto get feature surface and datum of the process feature. Feature extraction and process informationmodeling based on feature surface and datum is realized. And then the digital connection betweenprocess information and design geometry is established.(4) According to information form characteristics of assembly process mock-up and frequent modification of aircraft product design, the process information management scheme based onhierarchical code is put forward. Process code and design code is combined to represent processinformation, which not only can clearly express the level and subordination of master model and otherprocess information, but also can establish the connection between assembly process mock-up anddesign model. And then unified representation and management of assembly process mock-up anddesign model can be realized. Modification response mechanism between the two models isresearched. By means of hierarchical code and geometric reference, the process informationmodification with product design modification is realized.(5) A modeling software system for aircraft assembly process mock-up is developed. The systemhas been used in a certain type of aircraft assembly process design. The system can meet the needs oftransfer and distribution of digital process data. The efficiency of assembly process design isimproved greatly.