Research And Development On Digital Assembly Path Planning System For Valve Products

Assembly is an important procedure in product manufacturing process,and the assembly quality has direct influence on the usability of the product.Complex products have the characters of high research and development cost,large quantity of parts,complicated structure and assembly relation,large capacity of data,etc.In order to realize information sharing and integrating between CAD and CAASP,as well as CAAPP,the assembly path planning technology of complex products is researched,with the case of complicated valve products.The assembly information models are established with the polychromatic sets theory,as the model foundation of assembly path planning.The calculation method for assembly direction is described based on interference matrix information.The assembly path planning automatic search algorithm is studied.And an algorithm of improved deviation target rapidly-exploring random tree(Goal Bia-RRT)is proposed for the assembly path planning.The algorithm adopts sampling strategy and node extension strategy mainly to improve RRT algorithm,and it is based on the partial target extension strategy,using chaotic mapping distribution instead of the traditional RRT uniform random distribution sampling.The generation of new nodes are guided with local collision information and the golden section rule,which not only retains the characteristics of being fast and efficient of GoalBia-RRT algorithm,but also solves the problem that complex assembly environment search path is easy to fall into local minimum region at some degree,and the superiority and effectiveness of the improved algorithm are verified through the simulation test.To share the assembly planning information,MBD technology is adopted to study the composition and expression method of MBD data set facing assembly path planning,realizing integration of assembly path planning information and the 3D model.Finally,based on the improved RRT algorithm,with the CATIA platform via secondary development tool CAA,the digital assembly path planning system is constructed,and the assembly path planning and simulation is tested with the case of the blind flange valves.