Feasibility Analyze for Double-Load AGVS of Limited Buffers

• Main Authors: Yeh, Ting-Chieh, 葉丁介
• Other Authors: Yang, Neng-Sha
• Format: Others
• Language: zh-TW
• Published: 1997
• Online Access: http://ndltd.ncl.edu.tw/handle/62284041161456451507

碩士 === 國立雲林科技大學 === 工業工程與管理技術研究所 === 85 === An Automated Guided Vehicle System (AGVS) is a common material handling device a flexible manufacturing system. The tandem AGVS is so popular because it is easy to control. When an AGVS was designed in the old day, feasibility inspection of loop included two inspection functions. One is check on handle ability of AGV, the other one is check on arrival rate of empty vehicle. Despite, the two functions are essential conditions that are check on feasibility of loop, but these build on the hypothesis that capacity of buffers is unlimited. In other words, when the buffers are big enough, the two functions have higher limit ability. Once the buffers are limited for hardware, the loop will not operation for deadlock. Therefore, the purpose of this research is building an inspection model on unlimited buffers. And understand how elements influence the performance of system. At deadlock, this research suggests that deadlock problem could be solved by double-load AGV. At the same time, this research bring up the process that moving of double-load AGV and solving deadlock. By this process, double-load AGV could detect the deadlock and eliminate deadlock by two buffers of AGV. In this research, throughput of system, utilization of AGV and average flow time are selected to be the standards to analyze the influence of system of limited buffers by elements by simulation. The results show that increasing the degree of deadlock, reducing the capacity of buffers and broadening loop system would reduce the throughput of system. The larger product, throughput of system multiply the average moving distance of parts, is, the larger utilization of AGV is. Increasing the capacity of buffers and broadening loop system would increase average flow time. At the same time, this result found that the degree of deadlock and size of loop system have low influence when speed of AGV is fast enough. But increasing speed of AGV could not reduce the influence of capacity of buffers. Besides, increasing the capacity of buffers could reduce the deadlock to occur. For this reason, the set of capacity of buffers is one of important elements when designers plan the tandem AGVS.