# TBTAK An Optimization Approach for Airport Ground Operations

TÜBİTAK An Optimization Approach for Airport Ground Operations with A Shortest Path Algorithm 12 November 2015 Orhan Eroglu - TUBITAK BILGEM, Turkey Zafer Altug Sayar - TUBITAK BILGEM, Turkey Guray Yilmaz – Tur. AFA ASTIN, Turkey

Overview TÜBİTAK • Introduction • Floyd-Warshall Shortest Path Algorithm • The FLOW-GRO System • Conclusion • Future Work

TÜBİTAK Introduction

Introduction TÜBİTAK • TUBITAK, BILGEM: The Scientific and Technological Research Council of Turkey, Informatics and Information Security Research Center • Department of Aeronautics Ø Air Traffic Control Studies Tower Simulator • 3 D IG Systems • Ground Radar Control • Ground Optimization Radar Simulator • Approach/Enroute Radar Control

Introduction TÜBİTAK • Ground Radar

Introduction TÜBİTAK • Air traffic seems to going to have twice or three times the current density, in 2020’s [1] • Ground route conflicts everywhere! Ø Revise and optimize traffic control procedures and standards, improving monitoring abilities by development of new traffic surveillance and communication technologies Ø Harden the practices of air traffic controllers Ø Develope new decision support systems [2] usable for controllers to manage ground traffic Ø Route conflicts and routing delays may occur more often when taxiing of vehicles is not performed in the shortest possible way [3] Ø Support human controllers by computer systems

Introduction TÜBİTAK In this study, a computer system is proposed, which generates the shortest path between two points during the taxi procedures of ground traffics

TÜBİTAK Floyd-Warshall Shortest Path Algorithm

Floyd-Warshall Shortest Path Alg. TÜBİTAK • Finds shortest paths between all node pairs in a weighted graph. • Easy to implement • Not much challenging but proposes an appropriate application for the domain.

Floyd-Warshall Shortest Path Alg. TÜBİTAK • Input: Ø The graph array: Holds the edge weights between directly connected nodes. • Outputs: Ø Distance Matrix (D): Holds the distance of the shortest path between each node-pair, if exists. Ø Sequentiality Matrix (S): Holds the sequential relationship between nodes, i. e. it holds the last node before the terminal one, if it exists, in the shortest path between two nodes

Floyd-Warshall Shortest Path Alg. TÜBİTAK procedure [array] Floyd. Warshall(D, S) for k in 1 to n do for i in 1 to n do for j in 1 to n do if D[i][j] > D[i][k] + D[k][j] then D[i][j] = D[i][k] + D[k][j] S[i][j] = S[k][j] Return S

Floyd-Warshall Shortest Path Alg. TÜBİTAK • Pro’s: Ø Easy to implement Ø Very suitable for the problem space (ground traffic control) since airports can be represented as weighted graphs Ø Can be applied for the whole airport at first rather than time of ground operations • Con’s: Ø O( ) complexity Ø Number of iterations may drastically increase for huge airports with thousands of nodes

TÜBİTAK The FLOW-GRO System

The FLOW-GRO System TÜBİTAK • Airports as a node-based, weighted graph [6]: ØParking positions ØAprons ØTaxiway segments ØLineup areas ØRunway points Detailed view of the airport graph

The FLOW-GRO System TÜBİTAK • Performing the Floyd-Warshall algorithm on an airport graph: Ø To guarantee to find the shortest taxiway between any two airport nodes, mathematically • The FLOW-GRO System has been developed Ø The most interesting proposal: Deciding the edge weights Ø Euclidean distance is the very first option Ø Taxiway speeds may vary Inappropriate ØOur proposed weight: The minimum taxiing-time of each edge, which can be calculated by dividing the edge distance by the maximum allowed taxi speed

The FLOW-GRO System TÜBİTAK • The FLOW-GRO system has been examined several times in the ATC simulator system developed by TUBITAK-BILGEM Ø Includes database models of 4 different airports in Turkey Ø Each consists of hundreds of nodes, i. e. varying speed taxiways.

TÜBİTAK Conclusion

Conclusion TÜBİTAK • The study do not cope with the hardest challenges Ø Besides, it proposes the usage of a well-known method for a common problem in air traffic control: Ø Optimization of taxiway routings • A simple application work of a node-based algorithm in a domain of more complex computational problems

TÜBİTAK Future Work

Future Work TÜBİTAK • Inevitably, the system must perform dynamic conflict resolution in order to become more interesting Ø In addition to static computation of the shortest taxiways, the system may also determine whether conflict exists between different traffics dynamically Ø It may also propose the next possible shortest path for the conflicting ground traffics • It can be exploited for the sake of evaluating the ability of traffic controllers to generate the most appropriate taxiing routes over the ground movements

TÜBİTAK References

Future Work TÜBİTAK 1. H. Erzberger, "Transforming the NAS: The next generation air traffic control system. " 24 th International Congress of the Aeronautical Sciences, Yokohama, Japan. 2004. 2. A. P. Sage, Decision support systems. John Wiley & Sons, Inc. , 1991. 3. J. B. Gotteland et al. "Aircraft ground traffic optimization. " ATM 2001, 4 th USA/Europe Air Traffic Management Research and Development Seminar. 2001. 4. E. W. Weisstein, "Floyd-Warshall Algorithm. ", 2008. 5. R W. Floyd, "Algorithm 97: shortest path. " Communications of the ACM 5. 6: 345, 1962. 6. A. G. Marin, "Airport management: taxi planning. " Annals of Operations Research 143. 1: 191 -202, 2006.

TÜBİTAK Thank you…

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