Modelling and Simulation of Vehicle Movements using a SPPTW-Algorithm and the Application to Airport Surface Movements Analysis

Abstract

For the optimization of aircraft ground movements a method is described herein based on means of modelling and simulation. The paths of the vehicles are described as a network. Based on graph theory, an algorithm is developed that attempts to find the least time consuming, conflict-free path. The algorithm presented is based on one designed for Automated Guided Vehicles, which was adapted for an Advanced Surface Movement Guidance and Control System at airports. It is derived from a Dijkstra algorithm which calculates the shortest possible path between two nodes in a given network. Due to the fact that the time dependency of the planned paths are taken into account, approaches like this are called Shortest Path Planning with Time Windows (SPPTW), meaning that the path is segmented into parts of fixed duration. In case of a conflict, the vehicle is delayed in a preceding path segment or rerouted. The calculation of the paths for the different vehicles is initiated by a request, including the nodes at the start and at the end as well as the time at entry. The results of the simulations are used to estimate the performance of an airport airside system, with particular focus on the taxiway system.