液晶面板廠機台與無人搬運車指派機制之設計

Abstract

在液晶面板廠中，搬運系統的效率性會直接影響到生產系統的成效。首先在搬運距離上，規劃者若未對各產品的生產位置進行妥善指派，搬運系統可能因為搬運距離過長而造成負荷的增加。而車輛數目的決定亦會對搬運系統的效率產生影響，過少的車數可能無法完成搬運的負荷，過多的車輛可能使得車輛間碰撞的機率增加。現場機台阻塞的發生則會造成生產活動的停滯，因此派車法則的優劣亦會對生產系統產生影響。本文因此提出一套機台與車輛指派機制，以期生產系統能在既定的路徑設計下，順利達成主生產排程的預定產出目標。 本文針對以無人搬運車為搬運工具的液晶面板廠，設計各工作站內產品別生產位置指派與搬運系統車輛數指派機制。首先根據所給定之主生產排程結果，計算規劃週期內完成各產品產量所必須耗用之各工作站機台數目。據此資訊，本文設計了一線性規劃模式，並以最短化搬運總距離為目標來求解各工作站內各產品別生產的機台位置。接著，依據各產品別機台位置規劃結果來求算滿足主生產排程所需之必要搬運總距離，用以估算各工作站間所需要之車輛數目。在現場控制法則上，本文以避免機台阻塞及減少搬運距離為原則來設計派車法則以確保車輛搬運的效率性。 實例驗證的結果發現，生產系統確實可能因為搬運系統的規劃不當而使得產出無法達成應有的水準。而由模擬結果說明，本文所提出之派車法則能有效的避免機台因阻塞而造成的生產活動停滯。透過本文所提出的機台與車輛指派機制之運作，主生產排程的產出目標能在所既定的搬運系統路徑設計下順利達成。

In the TFT-LCD cell assembly factory, the efficiency of the transportation system will influence the performance of the production system directly. The load on transportation system will be increased due to unnecessary lengthening the moving distance. The number of vehicle will influence the transportation system’s efficiency too. With too less vehicles, the movement request may not be fulfilled. With too many vehicles, the probability of collision between vehicles will increase. Also, the blockage of machines will force the production progress being stagnated. The vehicle dispatch rule hence is critical to production system. Therefore, this thesis proposes the mechanism for assignment of machines and vehicles to fulfill the master production schedule under the given vehicle route design. In this study, the mechanism for machines and vehicles assignment is designed to fulfill the movement request in the AGV-based cell assembly factory. First, the number of machines needed to produce each product type in every workstation in the planning horizon is decided. According to the information, a linear programming model is built to assign the machines to each product type based on minimizing the moving distance. Then, total distance for transporting target throughput between any two consecutive workstations is calculated for deriving the vehicle units needed. This thesis then proposes a dispatch rule based on reducing the blockage of machines and on minimizing movement distance to enhance the efficiency of vehicle transportation. According to the simulation result, the production system is indeed influenced by the unsuitable scheduling of transportation system. Also, the proposed dispatching rule has the effect on preventing machine blockage that will cease the production progress. Experiments also show that through the application of the mechanism proposed, the master production schedule can be fulfilled under the given vehicle route design.