A Quality Flow Model in Battery Manufacturing Systems for Electric Vehicles

作者：Ju Feng^*; Li Jingshan; Xiao Guoxian; Huang Ningjian; Biller Stephan

来源：IEEE Transactions on Automation Science and Engineering, 2014, 11(1): 230-244.

DOI：10.1109/TASE.2013.2237765

• Battery
• bottleneck
• flow model
• monotonicity
• quality
• repair
• sensitivity
• serial line

Improving quality in large volume battery manufacturing systems for hybrid and electric vehicles is of significant importance. In this paper, we present a flow model to analyze and improve product quality in electrical vehicle battery assembly lines with 100% inspections and repairs for defective parts. Specifically, a battery assembly line consisting of multiple inspection stations is considered. After each inspection, defective parts will be repaired and sent back to the line. A quality flow model is introduced to analyze quality propagations along the battery production line. Analytical expressions of final product quality are derived and structural properties, such as monotonicity and sensitivities, are investigated. A bottleneck identification and mitigation method is introduced to improve quality performance. Finally, a case study is presented to illustrate the applicability of the method.
Note to Practitioners-Battery manufacturing is becoming more and more important due to increasing demand of hybrid and electric vehicles. To achieve a high volume production of high-performance battery packs, improving manufacturing quality is of critical importance. In battery assembly process, multiple inspections on dimension, stacking, welding, electrics, and leaking, etc., will be carried out to ensure battery quality, and repair stations are typically installed immediately after inspection to correct all the defects. The variation of individual processwill not only affect quality ratio at the specific inspection station, but also may propagate and accumulate along the manufacturing process, which can be viewed that there exists a quality flow along the line. Such a flow of quality characteristics may include multiple quality features (such as dimension, conductivity, joints, sealing, etc.) and have multiple repair processes. Developing a method to analyze such systems is of importance. In this paper, a quality flow model is presented to evaluate the quality propagation and investigate system-theoretic properties. Bottleneck identification methods are developed to improve product quality. A case study at a battery assembly line for electric vehicles is introduced to illustrate the method and its applicability.

• 出版日期2014-1