„ Fuzzy Expert” System for Determination of Runways in Use Case Study: Zurich Airport Fedja Netjasov University of Belgrade Faculty of Traffic and Transport Engineering Division of Airports and Air Traffic Safety

Airport Traffic Control Tasks Monitoring of departing and arriving traffic at the airport with aim of securing: - safe, - accurate and - expeditious traffic. This is obligation of Air Traffic Controllers who are located in the Airport Control Tower.

Airport Traffic Controller Duties Most important ones are: Airport Traffic Monitoring (directly through the window or by binoculars); Radio Comunication with aircraft pilots and ground handlung personal; Determination of runway(s) in use.

Determination of runways in use Problem definition For the case of multiple runways: depending on meteorological conditions and planned traffic demand, airport traffic controller determine the runways in use trying to “maximize” utilization of available airport capacity and “minimize” the noise level.

Problem nature Real Time Combinatorial Problem; Large number of feasible combination of runways; Large number of operational constraints; Conflicting Goals; Decision making process is dependant of controller’s subjective judgments.

Reasons for development of “fuzzy expert” model Usage of input data in different form (linguistic, quantitative); Individual differences between controllers (personal experience, age, personality, etc.); Better satisfaction of given criteria (maximization of capacity, minimization of noise level, etc.);

Conceptual model for determination of runway in use Determination of meteorological conditions on the basis of visibility and ceiling; Determination of operational concept in use on the basis of meteorological conditions, wind direction and runway condition; Aircraft assignment to runways in use on the basis of operational concept in use and estimated number of departures and arrivals

Fuzzy Model 1 Serves for the determination of meteorological conditions at a specific time using the fuzzy variable visibility and ceiling.

Fuzzy Model 1 (cont.) The output of the model is presented as fuzzy variables “preference of meteorological condition (VMC/MMC/IMC)”.

Fuzzy Model 2 Using fuzzy variables “planned hourly number of departures (arrivals)” and “absolute difference” determines the “estimated” number of departures and arrivals.

Fuzzy Model 2 (cont.)

Output from Fuzzy model 2 is presented as fuzzy variables “preference that number of departures (arrivals) is small/middle/large”.

Rule Base Based on results from Fuzzy Model 1 and 2, and using additional information on wind direction and runway conditions, as a result gives us the operational concept in use and distribution of traffic (by aircraft category) on runways in use.

A

Numerical example Meteorological data are: visibility – 3000 m; ceiling – 1100 ft; wind direction – 90 0 ; runway condition – wet. Traffic data planned for next hour are: planned number of departures - 29; planned number of arrivals - 11;

Concept A Concept B Concept C Concept D

Determination of meteorological condition VMC

Determination of number of departures MIDDLE

Determination of number of arrivals SMALL

Determination of final results

Conclusion and Further Research Developed model could serve for evaluation or for suggestion of decision; Model could be easily applied for any other airport; This is prototype of a model, so further verification and additional “fine tuning” is required.

University of Belgrade Faculty of Transport and Traffic Engineering Department of Air Transport Division of Airports and Air Traffic Safety Vojvode Stepe 305, Belgrade Serbia and Montenegro tel: fax: Thank you for your attention