WIT Press

The Contribution Of State Resources In A Constraint-based Scheduling Model For Conflict Solving At Railway Junctions


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WIT Press


J. Rodriguez


Scheduling is the process of allocating resources to activities over time. In a scheduling problem, resources are scarce and constrained in various ways (e.g. in the order of activities and the capacity of resources), and one is looking for a schedule of the activities that both satisfies the constraints and is optimal according to some criterion. Over the last decade, constraint-based scheduling (CBS) has become the dominant form of modelling and solving scheduling problems. This paper deals with a CBS model of real time management of train traffic through junctions, it focuses on the use of state resources to improve the model of conflicts between trains running in opposite directions. 1 Introduction The railway industry has to improve the quality of service provided in order to increase freight and passenger market-shares. One important parameter that affects the quality of service is the efficiency and the effective use of resources. To achieve this aim, one solution is the use of computer-aided systems in planning and traffic control. A significant part of these computer-aided systems involves the model and the solution method of the optimisation problem, associated with real situations and decisions to be taken. When traffic on connecting lines of a junction is heavy, the junction is likely to be a critical resource. As a consequence, small disruptions are amplified. A few seconds originally can quickly lead to a delay of more than 5 minutes. To limit this