Research On Intelligent Planning Of Assembly Sequence Based On CAD Model Data And Intelligent Algorith

With the development of digitalization and intelligence in manufacturing industry,assembly sequence intelligent planning has been proved to greatly improve the production efficiency of the whole product chain,effectively reduce the operating costs of enterprises and enhance their market competitiveness.Intelligent assembly sequence planning involves key technologies such as assembly data extraction,assembly sequence reasoning and feasibility verification of assembly sequence.In this thesis,by automatically extracting CAD model data for intelligent assembly sequence planning,reasoning assembly sequence based on hybrid intelligent algorithm and verifying the feasibility of assembly sequence by virtual collision detection,intelligent assembly sequence planning based on CAD model data and intelligent algorithm is studied to improve the automation and intelligence level of assembly sequence planning.The main research contents are as follows:(1)In the assembly data extraction stage,the automatic extraction method of CAD model data based on CATIA is studied.The data structure of CAD model based on CATIA is analyzed,and the automatic object programming interface(Automation API)based on CATIA software is programmed to realize automatic extraction of assembly data and constraint data in product CAD model.The data is stored in local Excel table by Excel VBA interface.To develop an automatic extraction system of CAD model data based on CATIA for assembly sequence planning,complete the extraction of assembly data and constraint data from product CAD model data,and provide data basis for assembly sequence planning based on hybrid intelligent algorithm.(2)In the reasoning stage of assembly sequence,aiming at the shortcomings of single intelligent optimization algorithm in solving product assembly sequence planning,a method of assembly sequence planning based on hybrid intelligent algorithm is proposed.Set up assembly data matrix;Reduce the complexity of assembly sequence arrangement and combination by hierarchical expression of complex products;Select ant colony algorithm as the basic framework,and introduce the crossover variation operation of genetic algorithm to accelerate the convergence speed of ant colony algorithm and improve the diversity of feasible solutions;The annealing mechanism of simulated annealing algorithm is introduced to avoid the algorithm falling into local optimum.Fitness function is constructed by synthesizing four evaluation indexes,namely,stability of assembly sequence,continuity of assembly sequence,number of assembly direction redirection and number of assembly tool changes.Hybrid intelligent algorithm for assembly sequence planning is designed and programmed.The feasibility of assembly sequence planning based on hybrid intelligent algorithm is verified with wind turbine bearing room as the research object.(3)In the stage of assembly sequence simulation and optimization,assembly sequence simulation optimization is realized based on Unity 3D development engine.Unity 3D collision detection technology is studied to verify the feasibility of hybrid intelligent algorithm in reasoning assembly sequence,and assembly sequence optimization is realized based on collision detection information and manual experience.The virtual assembly simulation system of wind turbine bearing room is developed by combining human-machine interaction mechanism,collision detection algorithm,user interface design and space mapping technology in Unity 3D to realize simulation and optimization of virtual assembly sequence of wind turbine bearing room.(4)An intelligent assembly sequence planning system based on CAD model data and intelligent algorithm is developed,which integrates the programs and software used for assembly data extraction,assembly sequence planning,assembly sequence simulation,assembly sequence optimization and assembly sequence evaluation.Taking bearing room of wind turbine as research object,the feasibility of assembly sequence intelligent planning system is verified.This research is based on CAD model data and several intelligent optimization algorithms,combining with CATIA,MATLAB,Visual Basic 6.0,Unity 3D and other software platforms,to study the solution of intelligent planning for complex product assembly sequence,and verify the feasibility of the solution,providing new ideas and references for intelligent planning of assembly sequence.