The Research On Assembly Sequence Planning Of Products Based On The Layer Reasoning

With the competition of manufacturing and rapid development of the newcomputer technology, in order to adapt the quickly changeable market requirement,new technology, new philosophy, new pattern and new ideology, such asComputer-Aided Design and Computer-Aided Manufacture, Computer IntegratedManufacture, No-paper Design in different place, Concurrent Engineering etc., emergein endlessly. In Concurrent Engineering, Digital product assembly planning usingcomputer can provide foundation for guaranteeing assembly feasibility andoptimization using actual product assembly procedure, and is very important inimproving production quality, decreasing product cost and shortening production time.This paper presents a research of Computer-Aided Assembly sequences planningand it related key technology combined under the research condition and practicalsituation both inside and abroad.The detail contains of this dissertation are summarized as follows:1. Assembly ModelingOn the basis of the discussions of the product assembly model based onConcurrent Engineering, some methods of assembly modeling and the "Bottom-Up"and "Top-Down" design methods and process are researched. The product assemblymodel technique is also researched.2. Assembly Sequence PlanningMethods is proposed to generate the assembly hierarchical relation tree based onthe product assembly sequence layer-built model;and then use the sub-assembly partsof the tree to generate the Mating Graph of the products. In order to confirm theultimate assembly sequence planning and reduce the work in the end, it is uses theBreadth-First Search in Mating Graph.3. Assembly Sequence EvaluationThe criterions of the most assembly angle, a reorientation, assembly parallelism,subassembly stability, assembly operation complexity, assembly clustering, assemblyhardness, assembly cost and their corresponding algorithm are proposed. This paperconsiders of most assembly angle as the base of assembly reorientation, subassemblystability, assembly operation complexity, assembly clustering, which has the advantageof simplification and efficiency in implement. The work is creative.Most of methods and algorithms are available and utilizable by implementing inan application instances. In the end this paper summarizes the dissertation and bringforward problem to study in this filed in future.