Metaheuristics for Air Traffic Management

Nicolas Durand, David Gianazza, Jean-Baptiste Gotteland, Jean-Marc Alliot

• Publisher: Wiley-ISTE
• Year: 2015
• Print ISBN:
  9781848218109
• Edition: 1
• eBook ISBN:
  9781119261537
• Topic: Computer Science
• Subtopic: Computer Engineering
• Index: Computer Science

Air Traffic Management involves many different services such as Airspace Management, Air Traffic Flow Management and Air Traffic Control. Many optimization problems arise from these topics and they generally involve different kinds of variables, constraints, uncertainties. Metaheuristics are often good candidates to solve these problems.   

The book models various complex Air Traffic Management problems such as airport taxiing, departure slot allocation, en route conflict resolution, airspace and route design. The authors detail the operational context and state of art for each problem. They introduce different approaches using metaheuristics to solve these problems and when possible, compare their performances to existing approaches

1
The Context of Air Traffic Management

This chapter is a short introduction to the air traffic management operational context.

1.1. Introduction

The aim of this chapter is to present clearly and concisely the current air traffic management (ATM) system, so that readers who are not familiar with it can understand the problems being addressed in this book. More detailed information on the rules and organization in ATM can be found in specific documentations such as [INT 01, INT 08], published by the International Civil Aviation Organization (ICAO).

ATM covers a wide range of activities, including air traffic control (ATC) in which ground-based controllers monitor aircraft and issue instructions to pilots in order to avoid collisions. Between the moment passengers board the aircraft and the moment they arrive at their destination, a flight goes through several phases: push back at the gate, taxiing between the gate and the runway, takeoff and initial climb following standard instrument departure procedure, cruise, final descent following standard terminal arrival route, landing on the runway and taxiing to the gate. During each phase, the flight is handled by ATC organizations: airport ground control, approach and terminal control and en route control. These control organizations provide services ensuring a safe and efficient conduct of flights, from departure to arrival.

The ATM system is highly complex. It handles a huge number of flights and involves many actors: airlines, air navigation service providers (ANSP), airports, national and international regulatory authorities, etc. In 2013, the ATM system controlled 9.6 million flights operating under instrumental flight rules (IFR) in Europe and 15.1 million in the United States. The Federal Aviation Administration estimates that its National Airspace System is in charge of 4,000–6,000 flights simultaneously¹ during peak hours.

Figure 1.1. Air traffic forecast in Europe.

Sources Eurocontrol/Statfor (ESRA2008).

In terms of future evolutions, the Asia-Pacific region is anticipated to undergo a rapid growth in traffic volume. In North America and Europe, the growth rate is expected to weaken. However, the global trend still points toward a traffic increase, as shown in Figure 1.1.

1.2. Vocabulary and units

The aviation community uses specific units and a specific vocabulary that needs to be introduced before describing the ATM system. An index of acronyms can be found at the end of the book.

Altitudes are expressed in feet (ft), or in flight levels (FL), with 1 FL = 100 ft. There are several definitions of altitude, but the most widely used is the geopotential pressure altitude, computed from the static air pressure p measured onboard the aircraft. FL are defined in reference to the isobar surface p₀ = 1, 013.25 hPa.

Distances are expressed in nautical miles (NM), with 1 NM = 1, 852 m. Velocities are expressed in knots (kts), with 1 kts = 1 NM/h.

The aircraft speed in the air is measured through dynamic pressure sensors. The true airspeed (TAS) is the actual aircraft speed in the air. The calibrated airspeed

(CAS) is the TAS that would be necessary at mean sea level to obtain the same dynamic pressure than that measured onboard the aircraft. If we neglect the instrument errors, the CAS is the speed used by pilots when operating their flight, together with the Mach number, which is the ratio of the TAS and the speed of sound in the air. Typically, a climbing aircraft will follow several climb segments at constant CAS, followed by a climb segment at constant Mach number, at high altitudes.

Aircraft fly in the air, and the air is in movement above the Earth’s surface. We also define velocity relative to the Earth’s surface, called the ground speed, expressed in knots.

1.3. Missions and actors of the air traffic management system

The objective of ATM is to ensure safe and efficient flights, from departure to arrival. This mission is carried out by a number of national or international organizations that provide different services to the airspace users.

There are different kinds of airspace users. General air traffic includes commercial flights, private flights for leisure or for affairs, special flights for geographic data collection, meteorological studies or any other scientific study, drones, gliders, aeromodelling, etc. Military air traffic includes flights with specific missions such as flight combat training, surveillance and in-flight refueling, and other military missions.

Several kinds of services can be provided to the users:

• – ATC services: 1) prevent collisions between airborne aircraft; 2) on the ground between aircraft and obstacles; 3) organize and expedite air traffic flows;
• – flight information services provide useful information and advice to ease safe and efficient traffic;
• – alerting services notify relevant organizations regarding aircraft in need of search and rescue aid, and assist such organizations as required.

While information services are not responsible for trajectory separation, control services are. Therefore, air traffic controllers issue instructions to pilots to maneuver the aircraft laterally, vertically or by adjusting speed or rate of climb/descent. When only the flight information service is provided, pilots take charge of collision avoidance.

The control, information and alert services are provided to users by ANSP. There are many actors interacting with one another in the ATM system: airports, air traffic control centers (ATCCs), airline operators, national and international regulatory authorities, military control centers and authorities, meteorological services, etc.

In order to avoid airspace or airport congestion, it is necessary to organize and regulate the traffic flows. This continental-scale network management is carried out in Europe by the Eurocontrol Network Management Operations Center (NMOC) that enforces air traffic flow management (ATFM) regulations when required so by ATC units anticipating overloads. In the United States, this regulation takes the form of ground delay programs (GDPs) concerning each one or several airports in a same area. These GDPs are coordinated by the Air Traffic Control Strategic Command Center (ATCSCC). Similar organizations exist in other parts of the world where the traffic is dense enough to require such flow regulations.

1.4. Visual flight rules and instrumental flight rules

Flights can be separated into two categories, depending on the level of equipment of the aircraft and level of qualification of the pilots. A flight may operate under visual flight rules (VFR) or instrumental flight rules (IFR).

Under VFR, the pilot must maintain a sufficient distance to the neighboring clouds and obstacles. He/she can fly only if the meteorological conditions are compatible with VFR, especially concerning the visibility. These flight rules are designed for light aviation, where the basic “see and avoid” principle is applied to maintain separation from other aircraft.

IFR are less hampered by degraded meteorological conditions. Because IFR flights are allowed to fly in low visibility conditions, they are generally controlled by an AT...

Table of contents

• Cover
• Table of Contents
• Title
• Copyright
• Introduction
• 1 The Context of Air Traffic Management
• 2 Air Route Optimization
• 3 Airspace Management
• 4 Departure Slot Allocation
• 5 Airport Traffic Management
• 6 Conflict Detection and Resolution
• Conclusion
• Bibliography
• Index
• End User License Agreement