Research On Assembly Model Reconfiguration Based On Unit Model

In response to the change of product functional requirements, and to rapid realize product assembly model reconfiguration, a method of assembly model reconfiguration based on unit model was proposed. Through the analysis of product information including function semantics, geometric constraint relation and so on, a method of assembly unit planning was proposed, unit model was built, and a new level 3 assembly structure tree, about product, unit, and relationship among units, was built. On this basis, through reconfiguring new assembly structure tree, the related changes of product function, structure, and information was come true, and then, the assembly model reconfiguration, which take unit as the basic element, was realized. Main works of this paper was as follows,(1) Function information model and relation information model among function parts were built, in order to make full information preparation for assembly unit planning. Based on the original product 3D assembly structure model, through analyzing product input, output and basic functional semantics, using "black box" function analysis, product function model was constructed. Through traversing product structure tree, parts information and geometric constraint information were got, and parts could be divided into function parts and fittings. On this basis, based on the relationship between function parts, through defining the geometric constraint information, fittings and assembly sematic between two function parts, relation model among function parts was built finally.(2) A new method of assembly unit planning, which was based on product function and structure, was proposed. Functional units was derived from function model, and function parts relation matrix was built based on relation model between function parts. Combined with the number of functional units, assembly basic parts was determined. Through analyzing related function parts of basic parts, combined with functional units, assembly unit planning was completed. On the basis of divided function parts, all parts information among unit was got, and next, unit information table and unit structure model were built, assembly unit planning was finished.(3) A method of assembly model reconfiguration based on unit model was proposed. Based on four basic logic method of assembly model reconfiguration including addition, deletion, movement and replacement, combined with the result of assembly unit planning, through constructing level 3 assembly structure tree about product, unit, and relationship among units, based on node of product, unit and relationship among units, assembly model reconfiguration based on unit model was classified realized, and associated changes about assembly structure, product function and assembly information were come true at the same time.Based on 3D modeling software SolidWorks and system development tools Visual Studio, assembly model reconfiguration system based on unit model was constructed. Some basic functions such as function modeling, assembly information modeling, assembly unit planning, model reconstruction, were realized.