Determination of the number of automated guided vehicles required at a semi-automated container terminal
- PDF / 162,685 Bytes
- 9 Pages / 595 x 842 pts (A4) Page_size
- 26 Downloads / 201 Views
#2001 Operational Research Society Ltd. All rights reserved. 0160-5682/01 $15.00 www.palgrave.com/jors
Determination of the number of automated guided vehicles required at a semi-automated container terminal IFA Vis*, R de Koster, KJ Roodbergen, and LWP Peeters Erasmus University, Rotterdam, The Netherlands This paper describes the development of a minimum ¯ow algorithm to determine the number of automated guided vehicles (AGVs) required at a semi-automated container terminal. At such a terminal the containers are transported by AGVs from the quay cranes to the automated stacking cranes and vice versa. A model and a strongly polynomial time algorithm are developed to solve the case in which containers are available for transport at known time instants. Keywords: logistics; container terminal; AGVs; networks and graphs
Introduction Containerised transportation was introduced in the early 1960s. The ®rst-generation ships had a capacity of about 400 TEU (Twenty-foot-Equivalent Unit; length of container is twenty feet). The steadily increasing proportion of cargo handled with containers has resulted in the use of much larger ships (capable of carrying 4000 TEU and more). In addition, there has been an increase in the importance of marine transport systems, including networks of ports and terminals. These ports and terminals are used for the transshipment of containers from a ship to other modes of transportation, such as barges, trains and trucks, and vice versa. To satisfy the demands of customers, such as short berth times of the ship, short lead times and high quality products, all operations must now be carried out quickly and ef®ciently. Furthermore, the strong competition between terminals means that it is essential to reduce the costs. An ef®cient terminal must therefore ensure that container ships are unloaded and loaded quickly. The introduction of much larger ships and the requirements for shorter ship handling times have made it necessary to develop new techniques and methods which allow effective coordination of all activities at a terminal. Most of the terminals use manned equipment. However, a few terminals, such as the port of Rotterdam, are semiautomated. The process of unloading and loading a ship at a semi-automated terminal is illustrated in Figure 1 and may be described as follows: when a ship arrives at the port, the containers have to be taken off the ship. This is done by manned quay cranes (QCs), which take the containers from *Correspondence: IFA Vis, Rotterdam School of Management, Erasmus University Rotterdam, PO Box 1738, 3000 DR Rotterdam, The Netherlands. E-mail: [email protected]
the ship's hold and the deck. Next, the QCs put the containers on automated guided vehicles (AGVs), robotic vehicles which travel along a prede®ned path. After receiving the container, the AGV moves to the stack. This stack consists of a number of lanes where containers can be stored for a certain period. These lanes are served by automatically controlled automated stacking cranes (ASCs). When an AGV arrives at
Data Loading...
