A review of design and control of automated guided vehicle systems <s> Static vehicle positioning strategy <s> Abstract One of the control decisions in the operation of an Automated Guided Vehivle (AGV) System is that of determining the home positions for idle vehicles. A home position is a location strategically selected within the AGV System network for holding idle vehicles. Such point selection is based on the system operational objective. In this paper, the problem of selecting the home positions vehicles in a single loop type AGV network is addressed. Several single loop home selection models, along with solution methodologies are presented. The models are constructed based on the objective of minimizing the dead travel time of vehicles. <s> BIB001 </s> A review of design and control of automated guided vehicle systems <s> Static vehicle positioning strategy <s> It is discussed how to determine the home location of idle vehicles in an automated guided vehicles (AGVs) with a loop guidepath to minimize the mean response time for a pickup call. Static positioning strategy is analyzed in which a single-parking space is allocated for all the idle vehicles. And dynamic positioning strategy is also considered where a new positioning location is assigned whenever a vehicle becomes idle. Both the cases of unidirectional and bidirectional guidepath are considered. We provide a numerical example to illustrate the algorithm developed for each case. <s> BIB002 </s> A review of design and control of automated guided vehicle systems <s> Static vehicle positioning strategy <s> Abstract An Automated Guided Vehicle System (AGVS) with a loop guide path is modeled as a discrete-time stationary Markov Chain. We consider the AGVS with an unidirectional loop guide path. It is discussedd how to estimate the mean response time, the utilization, and the cycle time of AGV for a delivery order. A procedure is suggested in order to determine the home location of idle vehicles in a way of minimizing the mean response time for an arbitrary delivery order. <s> BIB003 </s> A review of design and control of automated guided vehicle systems <s> Static vehicle positioning strategy <s> In the study of automated guided vehicles systems (AGVS), one assumption often made in the management of vehicles is the existence of either home locations or a circulatory loop to buffer or hold idle vehicles. A review of AGVS literature reveals that different researchers pursue one idle vehicle management policy or the other. In some studies, idle vehicles are assumed to circulate in some loops in the system while others assume they are routed to some dwell point locations where they are held until they are reassigned. When the dwell point option is implemented, different strategies for implementation are also available. However, what is generally lacking in references to dwell point strategies are the techniques for selecting the optimal or best dwell points for a given facility. In this study, the problem of dwell point or home location specification is addressed. The problem was modelled mathematically to determine the optimal home locations. The emphasis in the paper is on a unidirectional AGVS guid... <s> BIB004
Vehicle parking locations should be selected to minimize the vehicle response time to new movement requests or to evenly distribute idle vehicles over the network. Several positioning strategies are proposed in literature BIB001  . Four major approaches are: Central-zone positioning rule: a certain parking area in the vehicle network has been designated for buffering idle vehicles. This area can be close to stations with a high probability of a load transport request, or at battery-recharge or fuel stations. Circulatory-loop positioning rule: one or more cruising loops are defined for idle vehicles. When a vehicle becomes idle, it travels one of the loops until a transport order is received. Two other approaches use Markov chain theory BIB003 and network flow modeling BIB004 . BIB001 According to BIB001 , the optimal home location of a vehicle in the unidirectional loop coincides with the location of a workstation and the optimal home location of a vehicle in the bidirectional loop lies at the midpoint of an arc. Based on these characteristics and the traffic flow of the system, Egbelu proposes several algorithms to find the optimal location for idle vehicles. He also indicates that it is extremely difficult to control multiple vehicles in the bidirectional loop. BIB002 proposes a similar approach to minimize the mean response time for a pick up call and a single parking place policy is used. Gademann and Van de Velde 