Resource-constrained scheduling for maritime traffic management

National Research Foundation (NRF) Singapore under Corp Lab @ Universit

Decision making for improving maritime traffic safety using constraint programming

A*STAR-Fujitsu-SMU Urban Computing and Engineering Centre of Excellence; Singapore National Research Foundatio

Hierarchical multiagent reinforcement learning for maritime traffic management

Agency for Science, Technology and Research, Fujitsu Limited; National Research Foundation Singapor

Multiagent decision making for maritime traffic management

We address the problem of maritime traffic management in busy waterways to increase the safety of navigation by reducing congestion. We model maritime traffic as a large multiagent systems with individual vessels as agents, and VTS authority as the regulatory agent. We develop a maritime traffic simulator based on historical traffic data that incorporates realistic domain constraints such as uncertain and asynchronous movement of vessels. We also develop a traffic coordination approach that provides speed recommendation to vessels in different zones. We exploit the nature of collective interactions among agents to develop a scalable policy gradient approach that can scale up to real world problems. Empirical results on synthetic and real world problems show that our approach can significantly reduce congestion while keeping the traffic throughput high

The safety case and the lessons learned for the reliability and maintainability case

This paper examine the safety case and the lessons learned for the reliability and maintainability case

A HYBRID SELF-ORGANIZING SCHEDULING METHOD FOR SHIPS IN RESTRICTED TWO-WAY WATERWAYS

Traffic conflicts between ships are one of the most important reasons causing delays in restricted waterways. Aiming to improve the traffic efficiency, a hybrid self-organizing scheduling (HSOS) method for restricted two-way waterways is proposed. Ship transportation system is treated as a distributive and self-organized system under uncertainties. Each ship makes the decision on when to enter the waterway and how to keep the safe distance between them, while the VTS center could manage the direction of traffic flow according to the navigation situations. In order to reduce the traffic conflict between the opposite directions, small ships are given higher priority than the large ships in the same direction. When the large ships are accumulating, they are given higher priority than small ships in the same direction. The large ships are delayed while small ships decrease the waiting time. The trade-off between small and large ships can enhance efficiency by accumulating the large ships. Comparing the results from HSOS with First Come First Served (FCFS), it can effectively reduce the average delays brought by large ships, especially at high arrival rates

On green routing and scheduling problem

The vehicle routing and scheduling problem has been studied with much interest within the last four decades. In this paper, some of the existing literature dealing with routing and scheduling problems with environmental issues is reviewed, and a description is provided of the problems that have been investigated and how they are treated using combinatorial optimization tools

HADES: A multi-agent platform to reduce congestion anchoring based on temporal coordination of vessel arrivals—application to the multi-client liquid bulk terminal in the Port of Cartagena (Spain)

Ports are key factors in international trade, and new port terminals are quite costly and time consuming to build. Therefore, it is necessary to optimize existing infrastructure to achieve sustainability in logistics. This problem is more complex in multi-client port terminals, where quay infrastructure is shared among terminal operators who often have conflicting interests. Moreover, the berth allocation problem in liquid bulk terminals implies demanding restrictions due to the reduced flexibility in berth allocation for these types of goods. In this context, this paper presents HADES, a multi-agent platform, and the experience of its pilot use in the Port of Cartagena. HADES is a software platform where agents involved in vessel arrivals share meaningful but limited information. This is done to alleviate potential congestion in multi-client liquid bulk terminals, promoting a consensus where overall congestion anchoring is reduced. A study is presented using a mixed integer linear program (MILP) optimization model to analyze the maximum theoretical reduction in congestion anchoring, depending on the flexibility of vessel arrival time changes. Results show that 6 h of flexibility is enough to reduce congestion anchoring by half, and 24 h reduces it to negligible values. This confirms the utility of HADES, which is also briefly described.The authors would like to thank Port Authority of Cartagena for data supplied, and terminal operators of docks E010 and E011 for their suggestions