Research On Key Technology Of The Assembly Sequence Planning Based On The Hierarchal Cut-set Method

It is of great significance for improving product quality,shortening production cycle and reducing product cost through conducting the product assembly planning and solving the assembly sequence by using computer in concurrent engineering.The problem of generating the assembly sequence is the core of the assembly sequence planning research and the key link of computer aided assembly process planning.The problem of combination explosion in calculation arises along with the increasing number of parts during the generation of assembly sequence.This thesis puts forward the method of solving assembly sequence based on hierarchical cut-set method.The main research work is as follows.(1)Because the method of assembly sequence planning based on hierarchical cut-set is hard to solve the complex assembly sequence planning.This thesis proposes the general framework model of assembly sequence planning system on the basis of hierarchical cut-set method.The model includes the functional modules such as assembly modeling,generating assembly sequence,feasibility judgment of assembly sequence,evaluation and optimization of assembly sequence,assembly simulation and so on.(2)When solving the assembly sequence,the traditional cut-set method easily induces the problems such as complex graph,too many assembly sequences and so on. Therefore,this thesis proposes that the assembly sequence is solved by the hierarchal cut-set method.The assembly relation tree and the connection relation graph are divided by hierarchy firstly.Then the assembly level and-or graph is solved by the cut-set method.The hierarchal assembly sequence is calculated.Adopting the hierarchal cut-set method reduces the assembly sequence number.Thereby the method solve the assembly sequence explosion problem caused by high calculation complexity.(3)It is validated that the assembly sequence number of complex assembly solved by hierarchical cut-set method is less than the assembly sequence number solved by cut-set method directly through analyzing examples.The feasibility of solving assembly sequence by hierarchical cut-set method is verified by taking interference detection through motion simulation.