Research On Assembly Sequence Planning And Evaluation Of Body-in-white

With the rapid development of automotive industry, automobile production and consumption modes have changed dramatically. In terms of production, higher space and resources utilization ratio and lower cost are intensively concerned. In terms of consumption, higher quality, more individual, and faster update rate of automobile are required by consumers. All these prompt the development of concurrent engineering methodology, taking full account of the body welding process at the design stage. And the welding sequence planning is the key to BIW (Body in White) welding process.This paper proposed welding sequence planning based on graph theory and fuzzy composite evaluation with reference to mainstream BIW assembly process, welding sequence planning, and welding sequence evaluation methodology.According to features of unique hierarchical structure of BIW In welding process, analyzing the BIW structure and its design workflow, studying layout for BIW assembly line and welding process, this paper researched into the major body sub-assemblies, simplifying planning, transferring the body model to matrix by means of graph theory according to the assembly sequences. Matrix theory and computerized automatic planning can be employed for BIW sequence planning therefore. Then the BIW assembly sequence analysis is a matrix operation problem, which can be used by computer conveniently. The paper also proposed a computerized automatic planning process and algorithm. In this programe, fuzzy composite evaluation methodology was proposed, system of evaluation was established, by numerous evaluation standards and fuzzy evaluation results.Finally, the research output was applied to an engine compartment problem. The results for the example proved that the method is feasible and efficient.The research on BIW assembly sequence planning and evaluation has an important theoretical and practical significance in welding process design, car body design at simultaneous engineering, and body quality improvement and cost down as well.