• IE interfaces
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• v.15 no.1
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• pp.1-9
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• 2002

Tandem AGV system is obtained by partitioning all workstations into multiple zones assigning a single vehicle to each zone. In this paper, we propose an analytical model to design a tandem AGV system with multi-load AGVs. Using simulation, the performance of the proposed model is shown by comparing a conventional multi-load AGV system.

• Proceedings of the Korea Society for Simulation Conference
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• 1998.10a
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• pp.209-212
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• 1998

Tandem AGV 시스템은 기존의 AGV 시스템의 운영 문제를 쉽게 해결하기 위해 새롭게 제시된 개념의 시스템이다. 이와 같은 Tandem AGV 시스템의 성능은 설계적, 운영적 영향을 받게 된다. 본 연구에서는 Tandem AGV 시스템의 설계적 요소 중 한 부분인 Transfer Station의 위치를 결정하기 위한 알고리즘을 제시하였다. 그리고 시뮬레이션을 통해 그 성능을 평가하였다.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.509-512
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• 2000

AGV 는 자동화된 생산 시스템에 없어서는 안 되는 중요한 요소로 자리잡았다. 하지만 생산 시스템의 규모가 커짐에 따라 설계와 운영에 있어 많은 어려움이 생겼고, 이를 극복하기 위해서 새로운 형태의 AGV시스템이 제시되고 있다. 이중 대표적인 것이 Tandem AGV 시스템이다. Tandem AGV 시스템은 전체 시스템을 몇 개의 지역으로 분할하고, 하나의 지역에 한대의 차량을 할당하는 방식으로 운영의 효율성을 꾀하고 있다. 본 연구에서는 Multi-load AGV 를 사용하는 Tandem AGV 시스템을 설계하기 위한 효율적인 방법론을 제시하고자 한다.

• Journal of the Korea Society for Simulation
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• v.3 no.1
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• pp.1-16
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• 1994

In this paper, the modeling capabilities of an object-oriented simulator, AgvTalk is demonstrated by designing and simulating a conceptually configuration of AGV systems, known as the tandem configuration. The characteristics and design methodology in AgvTalk are described between the tandem configuration for AGV systems and conventional AGV systems. Also, simulation between the conventional AGV system and its corresponding tandem AGV system are compared with AgvTalk in the job shop environment. From the simulation results, the characteristics of each system observed are discussed.

• IE interfaces
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• v.8 no.2
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• pp.135-150
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• 1995

An object-oriented simulation modeling environment, AgvTalk, is presented to provide flexible modeling capabilities for simulation of many alternative AGV systems. The hierarchical features and modularity of AgvTalk create possibilities for the extension and reuse of simulation object components. Also, detailed behavior of each object in the AGV system can be modeled easily and exactly in AgvTalk because there are no limiting modeling constructs. The modeling capabilities of AgvTalk is demonstrated by designing and simulating a conceptually different configuration of AGV systems, known as, the tandem configuration. Between the tandem and conventional AGV systems, the characteristics and design methodology in AgvTalk are described. Also, simulations between two systems are compared with AgvTalk in the job shop environment.

• Industrial Engineering and Management Systems
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• v.6 no.2
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• pp.125-135
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• 2007

An automated guided vehicle (AGV) system is a group of collaborating unmanned vehicles which is commonly used for transporting materials within manufacturing, warehousing, or distribution systems. The performance of an AGV system depends on the dispatching rules used to assign vehicles to pickup requests, the vehicle routing protocols, and the home location of idle vehicles, which are called dwell points. In manufacturing and distribution environments which emphasize just-in-time principles, performance measures for material handling are based on response times for pickup requests and equipment utilization. In an AGV system, the response time for a pickup request is the time that it takes for the vehicle to travel from its dwell point to the pickup station. In this article, an exact dynamic programming algorithm for selecting dwell points in a tandem-loop multiple-vehicle AGV system is presented. The objective of the model is to minimize the maximum response time for all pickup requests in a given shift. The recursive algorithm considers time restrictions on the availability of vehicles during the shift.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.28 no.1
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• pp.55-63
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• 2005

This paper is to analyze the travel distance and the transport size of the vehicle when the AGV carries multiple-load in the tandem automated guided vehicle systems. The size of multiple-load represents the number of load that the AGV can carry simultaneously. The AGV can carry simultaneously multiple-load that load types are different. The transport system of the manufacturing system is a tandem configuration automated guided vehicle system, which is based on the partitioning of all the stations into several non-overlapping single closed loops. Each loop divided has only one vehicle traveling unidirectionally around it. The AGV of each loop has to have sufficient transport capacity that can carry all loads for given unit time. In this paper, the average loaded travel distance and the size of feasible multiple-load of the vehicle are analyzed. A numerical example is shown.

• IE interfaces
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• v.14 no.2
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• pp.111-119
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• 2001

A tandem AGV system is based on partitioning all the stations into non-overlapping single vehicle closed loops with additional stations provided as an interface between adjacent loops. For an efficient use of this configuration, it is required to solve the load routing problem(LRP), which is primarily based on the fact that a load may be handled by several vehicles and moved through several loops before it reaches its destination. In this paper, a heuristic based on genetic algorithm(GA) is first developed to solve LRP. The first model obtains the optimal route of each job and the optimal direction of each loop when the vehicle in each loop travels unidirectionally. The second GA model obtaines the optimal polling sequence of the empty vehicle in each loop, when the vehicle can move bidirectionally.