Research On The Constraint Management Of Virtual Assembly For Aircraft Conceptual Design

Assembly is an important step in the product's life cycle. Compared with other common mechanical products, the aircraft has greater number of parts and narrow space, so the process of assembly becomes complicated. Physical prototype is gradually replaced by digital mockup. The virtual assembly technology supplies easy and direct human-computer interaction interface, so that the simulation environment and simulation operation in the virtual environment can be closer to real word. Therefore, the realization of aircraft assembly simulation in the virtual environment is very significant for finding out and deal with the default of design in advance, reducing the design cost and optimizing product performance.In this thesis, on the basis of analyzing the research and application of constraint management domestically and abroad, the corresponding relation between assembly and geometry constraint and geometry constraint types used frequently were analyzed. A automatic geometry constraint recognition algorithm was proposed. This constraint recognition scheme such as required patch acquisition, constraint precedence judge, constraint parameter matching, destination position matching and constraint validity checking were adopted; On the basis of researching constraint management, constraint solving method was analyzed and chosen, and the equivalent relationship between geometry constraint and DOF was analyzed. The exact placement algorithm based on DOF was proposed.The application shows that this constraint solving method can solve constraint recognition and exact placement in virtual assembly. Some virtual assembly functions of virtual design environment based on CATIA has been realized. The research of the technologies provides good supports for the real and efficient realization of virtual assembly environment.