區域式無人搬運車路徑與設施佈置並行設計之研究

Abstract

不同於傳統網路式無人搬運車系統的派車、車輛途程及系統控制問題，區域式無人搬運車系統的車輛行走軌道是由數個互不重疊的迴圈組成，每一迴圈內由一輛無人搬運車負責物料搬運的工作，而系統內迴圈間設有轉運站可傳輸物件，當有一負載需跨迴圈搬運時，可藉由轉運站之物件傳輸來完成。本論文強調在自動化工廠內機器佈置未知之情況下，同時設計機器之分群與佈置，並決定無人搬運車之路徑及方向，以完成一區域式無人搬運車系統。在設計過程中，系統所需車輛數，各迴圈內所包含之機器數、無人搬運車之路徑方向，及迴圈內物料搬運量相對於該迴圈內之總物料搬運量(含跨迴圈物料搬運量)的比值均是迴圈內機器佈置之考量重點。 為求簡化設計過程中之計算複雜度，本論文進而提出一啟發式演法，以最小化物料搬運成本為目標來設計各迴圈內之設施佈置，且建議迴圈內之無人搬運車路徑採行雙方向性。該啟發式演算法之複雜經由驗證為O(n4)。 最後，本論文考慮區域式無人搬運車系統之負載途程問題，以最關鍵路徑(most vital link)之觀念，找出系統中之最關鍵路徑，也就是可能造成瓶頸之路段。在避免系統發生堵塞或碰撞現象的前提下，規劃系統內之負載途程。

A tandem automated guided vehicle system is composed of several nonoverlapping closed loops. Stations or machines within each loop are served by a single dedicated vehicle. The transit area located between two adjacent loops serves as an interface and allows loads to be transferred from one loop to another. If a load needs to be delivered to a machine not located within the same loop, the load will need more than one vehicle to carry it to its destination. This paper develops a model to solve the machine partition and layout problems concurrently in tandem AGV systems. During the design process, the objective is to minimize the number of loops to reduce the setup cost of AGVs in the system. Naturally, the desirability of a prospective loop must be evaluated in terms of the number of machines it covers, the workload of each AGV and the ratio of the flow within the loop to the total flow associated with that loop. As its subject, this paper proposes a heuristic algorithm to implement the facilities layout within each loop and the route of each vehicle in order to reduce the material handling cost. It is proved to be true that the heuristic algorithm is polynomial time complexity with O(n4). Finally, the load routing problem is considered in this paper. Based on the idea of the most vital link, the bottlenecks of the system are found. Under the premise of avoiding collisions, the routes for all vehicles in a tandem AGV system are planned. Key Words: tandem automated guided vehicle (AGV) system, machine partition, facilities layout, material handling systems, load routing problem.