Mark B. Duinkerken

Comparing transportation systems for inter-terminal transport at the Maasvlakte container terminals

In this paper, a comparison between three transportation systems for the overland transport of containers between container terminals is presented. A simulation model has been developed to assist in this respect. Transport in this study can be done by either multi-trailers, automated guided vehicles or automated lifting vehicles. The model is equipped with a rule-based control system as well as an advanced planning algorithm. The model is applied to a realistic scenario for the Maasvlakte situation in the near future. The experiments give insight into the importance of the different characteristics of the transport systems and their interaction with the handling equipment. Finally, a cost analysis has been executed to support management investment decisions.

Simulation of a multiterminal system for container handling

A generic simulation model structure for the design and evaluation of multiterminal systems for container handling is proposed. A model is constructed by combining three basic functions: transport, transfer, and stacking. It can be used for further detailing of the subsystems in the terminal complex while preserving the container flow patterns in the system. The modeling approach has been applied to the complete set of existing and future terminals in the Rotterdam port area, using forecasts of containers flows, statistical data from existing terminals, expert opinions, and conceptual designs of the new port area called “second Maasvlakte”. Experimental results including the requirements for deep-sea quay lengths, storage capacities, and equipment for interterminal transport are shown. Further traffic flows on the terminal infrastructure are determined, and the consequences of applying security scanning of containers are evaluated.

Comparison of routing strategies for AGV systems using simulation

In automated transport systems, the origin-destination combinations are normally connected through a fixed layout, not representing the shortest path. The flexibility of these systems is limited and often the infrastructure is not optimally used. With the introduction of more powerful onboard computers and advanced sensor technology, the positioning and navigating possibilities of AGVs increased. However the routes, although virtual, are still fixed. A new step ahead would be to determine each path dynamically. This would use the free ranging capacities of AGVs to its full potential. In this paper, the benefits of the dynamic free ranging approach are investigated; a simulation model on the strategic level is presented that compares several common fixed layouts with the shortest connection approach. Naturally, the avoidance of collisions plays a central role. It is concluded that dynamic free ranging has high potential in terms of transport capacity of the resulting system

The application of distributed simulation in TOMAS: redesigning a complex transportation model

This paper describes the application of distributed discrete event simulation in the study of an automated container terminal. The new model was developed to continue the study of large and complex logistic systems. In a previous study, a standalone model of the terminal was used that included all the characteristics of container handling between the ships and the container stack. A new distributed simulation model was developed by decomposing the original model into a distributed structure of communicating, small sub models. It is shown that with relatively little effort and hardly any programming overhead, a complex standalone model can be decomposed into small, easy to understand sub models. The new distributed structure improves the transparency and maintainability of the simulation model, while guaranteeing the original benefits of the standalone model and the required reproducibility of the experiments.

Dynamic Free Range Routing for Automated Guided Vehicles

In this paper an algorithm is presented that allows for dynamic free range route planning for automated guided vehicles (AGVs). This routing algorithm is based on the route choice methodology from a microscopic pedestrian behavioral model. Until now, AGVs use a map of predefined, fixed paths that are combined to obtain routes along which they move from origin to destination point. Although it allows for reliable and safe automation of vehicles with limited maneuverability, the use of fixed paths leads to unnecessary long routes, congestion, deadlocks and makes the routing system vulnerable to disruptions at the level of route execution. The developed routing algorithm dynamically determines free ranging trajectories that are optimized regarding arrival time while avoiding static obstacles and collisions with other AGVs

Decision support for vehicle configuration determination in Inter Terminal Transport system design

A dedicated Inter Terminal Transport (ITT) system must be able to efficiently transport containers inside the port area over a separate road preventing congestion on the ports entry roads, bundling incoming and outgoing container flows, and increasing competitiveness of the port. In this paper, a technique for decision support when designing inter terminal transport systems is proposed. In particular, a deterministic minimum cost flow model with time expanded graphs is presented. The model is able to support the design phase by quickly calculating an optimal vehicle configuration minimizing delays, saving time and money in the early phases of planning. In order to illustrate the potential of the model, it is applied for the proposed ITT system at Maasvlakte 1 and 2 areas in the Port of Rotterdam. The optimal configurations, as well as impact of various parameters, are determined.

Evaluation of inter terminal transport configurations at Rotterdam Maasvlakte using discrete event simulation

In this paper, various Inter Terminal Transport (ITT) systems for the Port of Rotterdam are evaluated. The Port Authority is investigating possible solutions for the transport of containers between terminals at the existing so-called Maasvlakte 1 and new Maasvlakte 2 areas within the port. A discrete event simulation model is presented that incorporates traffic modeling, which means that delays occurring due to traffic will have an impact on the systems performance. The model is applied to four different ITT vehicle configurations, including Automated Guided Vehicles (AGVs), Automated Lifting Vehicles (ALVs), Multi Trailer Systems (MTSs) and a combination of barges and trucks. Furthermore, three realistic demand scenarios for the year 2030 are used for the analysis.

Developing an AGV motion controller using simulation, emulation and prototyping

Today transport systems using automated guided vehicles (AGVs) are centrally controlled and use a fixed infrastructure. Substantial efforts are therefore necessary if expansion or a change in system layout is required. In addition, incidents cannot be handled as part of the common routine. To overcome these problems a distributed anticipatory control method for AGVs is called for. According to this method every AGV is made responsible for its own path planning and collision avoidance. This approach requires a highly accurate controller to enable the AGV to follow its planned trajectory. This paper describes the development and testing of a controller for both positional and speed control. The AGV is modelled as a simple system with two steering wheel axles and an electromotor. The theoretical results obtained by using Matlab, are compared with results from testing the controller using an emulation model. Finally, the controller is implemented on an actual vehicle prototype, scaled 1:25, representing an AGV used for sea-container transport. The results of this research can be used to develop a controller, which is capable of achieving the required accuracy for automated, large scale, container transport systems.

Simulating the operational control of free ranging AGVs

Most transport systems using automated guided vehicles (AGVs) are centrally controlled and use fixed, pre-defined routes. Incidents cannot be handled as part of the common routine. Instead of using fixed path layouts, new trajectory planners for AGVs are developed that utilize the complete available space. To accommodate the increased flexibility, new operational controllers must be able to adapt to small deviations and incidents. In this paper an operational controller is presented that aims to satisfy two conflicting goals. First, the controller directs an AGV along a preplanned trajectory with high accuracy. Second, the controller will avoid conflicts with static and dynamic obstacles. These conflicts are caused by small deviations between planned and realized paths, as well as by incidents like equipment failure. A simulation model is built to study the performance of this controller. The quality is compared to a PI-controller without collision avoidance characteristics

Quality-Aware Modeling and Optimal Scheduling for Perishable Good Distribution Networks: The Case of Banana Logistics

Modern technologies have enabled approaches to estimate freshness of perishable products during production and distribution. Nevertheless, the loss of perishable goods is still high due to the deteriorating nature and inefficiencies in supply chains. This research focuses on improving the scheduling of banana logistics using real-time quality information. Bananas are typically shipped from tropical production sites to other places in the world. With temperature controlled reefer containers and sensor technologies, bananas can be monitored during transport and situations like early ripening can be predicted. In order to minimize spoilage, we propose a mathematical model for scheduling logistics activities with the consideration of both the biological process and the logistics procedure of bananas. Results of simulation experiments indicate that the method could reduce spoilage using real-time monitoring and scheduling.