• 대한산업공학회지
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• 제18권2호
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• pp.65-82
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• 1992

We present an approximate analytical model to estimate throughput capacity and expected waiting times for move requests of an Automated Guided Vehicle System(AGVS) used in manufacturing. This analytical model considers an empty vehicle dispatching rule, namely, the First-Come-First-Served(FCFS) rule. The performance of the analytical model is tested extensively through simulation. Using this model one can rapidly evaluate a wide range of handling and layout alternatives for given flow data. Hence, the model would be most effective when used early in the design phase to narrow down the set of alternative handling systems and configurations prior to simulation.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2009년도 공동학술대회
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• pp.149-150
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• 2009

The problem of vehicle routing problem(VRP) with pair operations of pick up and delivery are well-known in real applications in logistics networks, as in planning the routes for automatic guided vehicles(AGVs) in an automatic container terminal(ACT), warehouses or in some just-in-time services. This paper will present a formulation to modeling the problem mathematically which can be used to generate optimal routes of carried vehicles in the field to reduce the incurred cost of moving goods. This selected model could be used in (semi-)automatic short-term planning systems for vehicle fleet working in ACT, or in modern warehouses which the long list of requests is parted and sorted in preprocessing orders systems.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1773-1774
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• 2007

본 논문은 AGVS(Automated Guide Vehicle System)가 여러 작업환경 및 변경 시 좀더 유연하게 대응할 수 있도록 작업환경 내에서 AGVS에 필요한 작업공간요소로 분류하고 이들을 모델링하는 방법을 제안하였다. 또한, 최단경로 생성 시 $A^*$ 알고리즘에서의 평가함수 선정 방법과 최단경로 상에 존재하는 경로의 충돌 모델을 제안하였으며 시뮬레이션을 통해 제안한 방법을 증명하였다.

• 산업경영시스템학회지
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• 제12권19호
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• pp.73-78
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• 1989

This paper concerns the production model that the Automatic Guided Vehicles(AGVs) is used as transporters in assembly line. The model suggests that assembly parts may inter the beginning of the line in multiple units instead entering one unit at a time. Costs are occured in proportion to the number of vehicle on the line and job flow time. Here, the objective of this model is to determine the number of vehicle to minimize the total cost for M products production. Theoretical results are proved which lead to the development of algorithm for solution search. The solution search procedure is illustrated by a numerical example.

• 산업경영시스템학회지
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• 제14권23호
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• pp.47-55
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• 1991

In automated assembly line, an automatic guided vehicle system(AGVS) represents a mire versatile means of moving materials automatically. In this paper, the vehicles not only provide the transportation medium between workstations but also as mobile workstations. The objective for the developed model is the determination of the appropriate time to control AGV based assembly line in order to minimize production makespan while maximizing the efficient use of vehicles. In this paper, we consider the finished goods of two types which are produced in assembly line. The assembly line is considered with and without queue. Because no buffer are present in case 1. this model seeks to determine the point in time at which vehicles should be launched in the assembly line without experiencing a delay. The case 2 model also seek to determine the vehicle launch times while minimizing production makespan. The assumption in this model is that the maximum queue size cannot exceed 1 at any time.

• 디지털융복합연구
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• 제15권5호
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• pp.207-215
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• 2017

세계는 급속한 IT 기술의 발달과 생명공학의 발달로 인간 수명이 급격하게 연장되어 노령화가 사회문제가 되는 시대에 살고 있다. 이러한 노령화 문제는 제조공장 또는 물류창고의 물류운송공장에서의 인력을 대신할 수 있는 무인운반차가 대체로 옮겨지고 있다. 이러한 무인운반차 사용의 증가세는 매년 큰 폭으로 상승하고 있으며, 스마트공장 내에서만 사용하던 무인운반차는 항만의 거대한 컨테이너를 운반할 수 있는 컨테이너 운반용으로 변모하고 있어 실내에서 실외로 그 활용성을 더욱 확장하고 있다. 이렇게 활용도가 증가하고 있는 무인운반차의 중요도가 높아짐에 따라 이를 제어하는 RCS(Remote Control System)의 중요성도 역시 증가하고 있다. 본 연구에서는 무인운반차 RCS의 품질평가체제의 확립을 위해 다양하게 발전하고 있는 무인운반차의 특성과 기술동향 그리고 무인운반차 RCS의 기술적 특징을 조사 분석하여 이를 바탕으로 무인운반차 RCS의 신뢰확보를 위해 국제품질평가 표준인 ISO/IEC 25000 시리즈를 참조하여 기능적합성과 사용성의 평가항목을 도출하고, 도출된 기능접합성과 사용성의 평가항목을 통해 평가모델을 개발하고자 한다.

• 대한산업공학회지
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• 제20권3호
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• pp.151-166
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• 1994

The manufacturing environment on which this research is focused is an FMS in which AGVs are used for material handling and each part type has one or more process plans. The research aims at developing a methodology whereby, given a part and volume mix for production during any production session, the best set of process plans including one plan per part type is selected and the best unidirectional AGV guidepath can be dynamically reconfigured in response to changes in parts and lot sizes combination. For the integrated PPS/FGD problem in which two functions of process plan selection (PPS) and flexible AGV guidepath design (FGD) are integrated, a zero-one integer programming model is developed. The integrated problem is decomposed into two subproblems, process plan selection given a directed AGV layout and AGV guidepath design with a fixed process plan per part type. A heuristic algorithm that alternately and iteratively solves these two subproblems is developed. The effectiveness of the heuristic algorithm is tested by solving various randomly generated sample problems and comparing the heuristic solutions with those obtained by an exact procedure. From the test results, the following conclusions are drawn: 1) For a reasonable size problem, the heuristic is very effective. 2) By integrating the two functions of PPS and FGD, a remarkable benefit in total production time for a given part and volume mix is gained.

• 산업경영시스템학회지
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• 제34권1호
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• pp.1-8
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• 2011

Controlling industrial vehicle operated by human in warehouse was not simple since the information transfer for controlling the vehicle was not easy. However, as the technology for the WMS (Warehouse Management System) has been advanced and the PDA (Personal Digital Assistant) has come into wide use in a workplace, the control of man-operated vehicle became less difficult as do to AGVS (Automated Guided Vehicle System). This study examines the ways to improve the efficiency of warehouse operation through introducing rule of task assignment for the vehicles, particularly forklift. This study, basically, refer to AGV operation policy because a great number of studies for AGV dispatching rule have been done and the mechanism for the controlling vehicles is very similar. The workers in field prefer to simple dispatching rules such as Shortest Retrieval Time First (SRTF), Shortest Travel Time First (STTF), and Longest Waiting Time First (LWTF). However, these rules have potential disadvantage. Thus, several rules made up by combining rules mentioned above are introduced and these new rules use threshold value or evaluation formula. The effectiveness of these new rules are tested by simulation and the results are compared. This study proposes favorable dispatching rules for forklift in warehouse for the efficiency of the vehicle operation and stability of service level.

• 로봇학회논문지
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• 제5권4호
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• pp.332-338
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• 2010

This paper presents a study of path-planning method for AGV(automated guided vehicle) based on path-tracking. It is important to find an optimized path among the AGV techniques. This is due to the fact that the AGV is conditioned to follow the predetermined path. Consequently, the path-planning method is implemented directly affects the whole AGV operation in terms of its performance efficiency. In many existing methods are used optimization algorithms to find optimized path. However, such methods are often prone with problems in handling the issue of inefficiency that exists in system's operation due to inherent undue time delay created by heavy load of complex computation. To solve such problems, we offer path-planning method using modified binary tree. For the purpose of our experiment, we initially designed a AGV that is equiped with laser navigation, two encoders, a gyro sensor that is meant to be operated within actual environment with given set of constrictions and layout for the AGV testing. The result of our study reflects the fact that within such environments, the proposed method showed improvement in its efficiency in finding optimized path.

• 한국항공우주학회지
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• 제38권2호
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• pp.180-187
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• 2010

본 논문에서는 위성항법 기반의 위치 정보만을 이용하여 저속으로 운행하는 이동체의 제어 성능을 확인하기 위해서 골프장에 무인으로 운행하는 AGV(Autonomous Guided Vehicle)를 위성항법 기반의 AGV로 구성하여 조향 시험을 수행하였다. 이를 위해 기존 AGV 시스템의 구성에 대한 분석을 수행한 후 위성항법 기반의 위치 정보를 이용하여 조향 제어가 가능하도록 제어기 및 조향 제어 알고리즘을 개발하였다. AGV의 조향 성능을 알기 위해서 직선과 원형으로 이루어진 기준궤적을 생성하여 시험을 수행하였으며 시험 결과 기준궤적에서 ${\pm}0.2m$ 범위 안으로 조향 제어가 가능함을 확인하였다.