Nowadays, the Air Transportation sector faces one of the greatest challenges of all its history. In a time when technological advances in many areas (such as computational methods, computer aided design and production, materials, engines, information technologies, communications and automation) are revolutionizing air vehicle aeronautics, paradoxically, the system responsible for their sustainable, efficient, and safe operation is reaching the limit of its capabilities.
Most commonly known as Air Traffic Management (ATM) system, it was developed as a result of the intensive regulatory and technical efforts that followed to the Chicago Convention of 1944 on International Civil Aviation. The ATM system encompasses an impressive framework of regulations, operating procedures, services and infrastructures which, together, realize the so-called operational concept or, in other words, the paradigm that establishes how civil air transportation operations are carried out along with the necessary resources and roles and responsibilities of the actors involved.
Born from the technology existing after the 2nd World War, the ATM system of today is the result of more than 60 years of continuous evolution, along which key technological advances as well as procedural and regulatory improvements introduced have enabled air transportation attaining the highest safety record ever achieved by any other transportation means.
A far less satisfactory view comes up, nonetheless, when considering other system quality of service (QoS) parameters such as capacity, efficiency, environmental impact, flexibility to accommodate airspace users’ preferences or the –ever increasingly important– security aspects. As an example, only in Europe, the yearly cost of the so-called route inefficiencies1 reaches €2.4B2 and a higher inefficiency figure is estimated for Terminal Maneuvering Area (TMA) operations meanwhile the cost due to delays and cancellations annually exceeds €8B.
The large room for improvement in the mentioned QoS performance aspects arises from the many limitations of the operational concept currently in use, such as excessive safety margins, fixed-route airspace structures, altitude and speed constrains, step-down descent trajectories, in-flight holding, VHF voice communications and a long list of etceteras. A significant part of these limitations are related with the need to guarantee safety of aircraft operations in presence of a high level of uncertainty about the aspects that determine their trajectories3 with no tool other than the brain of the human agents4 in charge.
All this results in four known sources of difficulties in the ATM system of today, namely; i) the central responsibility of the human element as sole source of predictability, ii) the reduced look-ahead time of the predictions, which confers decision making an eminently tactical character, iii) the inability of third-party agents (human or systems) other than the ones in charge of predicting the traffic situation to take part in the decision-making process and, as a result of all of this, iv) the need to fit aircraft trajectories to the ATM system limitations instead of being the ATM systems what accommodates the user-preferred trajectories.
The technological advances introduced throughout the history of aeronautics have allowed the ATM system to overcome the successive traffic capacity crises caused by the sustained increase of air transportation demand, whilst at the same time, continuing to enhance the levels of safety and reduce the environmental impact in relative terms, always avoiding substantial changes in the operational concept. However, in view of the requirements deemed necessary to satisfy the demand foreseen by the year 2020, all points out that a similar solution –i.e. one that does not involve relevant changes in the operational concept that sustains the ATM system– will no longer be possible.
The increasing political and industry awareness of this situation, both in Europe and in the USA has led to the launch of two large initiatives (respectively SESAR and NextGen) aimed at mobilizing during the next decades considerable investments in the modernization of the ATM system. In the context of the European initiative, the objectives of SESAR are to treble ATM system capacity, whilst at the same time reduce by 10% the environmental impact and by 50% the cost incurred by the ATM system users; all of this whilst maintaining at least the current levels of safety.
With similar objectives, the European and North-American initiatives advocate for the replacement of the current operational concept centered on the management of airspace volumes by human controllers that have a pro-active active function on diverse processes, with a new concept called TBO (Trajectory-Based Operations). In TBO, the aircraft trajectory becomes the fundamental resource for air space management and the role of the human element shifts to focus on supervising/taking decisions about optimal solutions provided by advanced automation tools. These tools will allow a collaborative and strategic approach to the management of the aircraft trajectories ultimately facilitated by a net-centric service-oriented architecture.
A long way lies ahead in maturing and developing the still much contested TBO concept, which to date has only been developed up to a very preliminary high level. The implementation of the new paradigm still requires considerable investment on R&D effort to elucidate and demonstrate the optimum scientific-technical approach that will realize it, which is a precondition for overcoming a vast list of difficulties that result in enormous reluctance to the change. These difficulties arise from the extraordinary complexity of the systems of systems that is the ATM, which is extensively multidisciplinary and global in nature and subject to a multitude of economic, political, cultural, technological, geographical, and geophysical aspects regulated through different institutional frameworks. These aspects are also subject to a complicated balance of cost-benefit considerations and stakeholder interests. Moreover, this balance is to a large extent unknown, due to the limitations of analytical and experimental means, as well as to the absence of a concrete referent that makes evident the feasibility of a solution centered upon the future paradigm whilst enabling its evaluation.
If all this was not enough, the global socio-economics and politics evolution along with the recent technological advances have precipitated the rise of new airspace users such as the Unmanned Aerial Vehicles (UAVs) and the Personal Aerial Vehicles (PAVs), of whose phenomena the known Very Light Jets (VLJ) do only constitute the tip of the iceberg. Due to these emerging users, during the next decades the demand for air vehicle operations might exceed by an order of magnitude that one foreseen for conventional aviation, which confronts the future ATM system with new challenges of very considerable proportions.
Fig. A1. Schematics of the ATLANTIDA experimental setup
In particular, Unmanned Aerial Vehicles (UAV) sit at the technological fore-front with respect to automation of air vehicle operations, and so for this reason, the integration of these operations in the ATM system is often perceived as the most difficult problem that the solution for the future ATM system needs to address.
However, these emerging users that confront the ATM system with the greatest difficulties do also provide a unique opportunity to develop the solution – and this idea is exactly the rationale behind the ATLANTIDA initiative.
With a budget of 28,9 million euro (44% financed by the Spanish Center for the Technological and Industrial Development, CDTI) and 2010 as the time horizon, the ATLANTIDA project will tackle the technological and scientific challenges that need to be addressed for high levels of automation to be introduced into the management of complex air spaces. ATLANTIDA (Application of Leading Technologies to Unmanned Aerial Vehicles for Research and Development in ATM) will explore an approach for automation in the management of air traffic seamlessly applicable to any air vehicle operations, including conventional aviation, civil and military UAVs, VLJ operations and the futuristic personal air transport systems.
To this end, the development of advanced high-fidelity simulations are planned along with the employment of experimental means based on UAV platforms, which will allow the development, validation and ultimately the evaluation of innovative concepts and technologies for air vehicle trajectory management in a net-centric environment, in line with the premises of the TBO paradigm. To achieve this, the project is organized into 15 R&D activities grouped up into 4 Blocks as illustrated in the figure.
Fig. A2. ATLANTIDA project’s work breakdown structure
The core of the technical approach that sustains the ATLANTIDA initiative consists on an advanced technology being developed by the Boeing Research & Technology Europe (BR&TE) center known as Aircraft Intent Description Language (AIDL).
The AIDL is a formal language that describes arbitrary air vehicle trajectories with minimum information and no ambiguity at all, thereby enabling the possibility to exchange them throughout the different automation tools that will realize the TBO paradigm, eventually addressing an important set of the central problems inherent to the new concept.
BR&TE leads the ATLANTIDA Consortium, which encompasses another 16 leading aerospace, information technology and communications companies: Indra Sistemas, Atos Origin, TCP Sistemas e Ingeniería, GMV Aerospace & Defense, Altran Technologies, TTI Norte, Aernnova Engineering Solutions, INSA (Ingeniería y Servicios Aeroespaciales), Aertec Ingeniería y Desarrollos, Indisys (Intelligent Dialogue Systems), Integrasys, Aerovision Vehículos Aéreos, MDU (Militärtechnologie Dienst Überwachung), Isdefe (Ingeniería y Sistemas para la Defensa de España), Catón Sistemas Alternativos and Iberia Líneas Aéreas de España. The consortium also includes 16 prestigious public R&D entities, among which are the Spanish universities more reputed in the aforementioned technologies.
The project has received explicit endorsement by Eurocontrol (the European agency for Air Navigation safety), and has invited the major international ATM R&D and UAS (Uninhabited Aerial Systems) organizations, such as the European Commision, NASA, FAA, as well as numerous international providers of air navigation services to join its international advisory committee.
A remarcable aspect of the ATLANTIDA initiative is that it represents the main International R&D effort in the area of civil UAV operations and the third largest effort related to ATM, complementing the SESAR and NextGen initiatives. Along with the considerable knowledge and expertise present in the consortium, the ATLANTIDA project will allow the participating industry, universities and professionals to consolidate their position as global leaders in development of the technology for future UAS and ATM systems, a field in which, even after a century of aviation, it still appears possible to be pioneers.
1 2 Data source: Eurocontrol Performance Review Commission 2007 report.
3 Essentially, atmospheric conditions, the way in which the aircraft is solicited and its response or performance
4 Basically, pilots and air traffic controllers
5 The Polytechnic University of Madrid, through its High Technical Schools of Aeronautical and Telecommunications Engineering, various groups of University of Sevilla and its ascribed foundation, the Association for Industrial Research and Cooperation of Andalucía, The universities Rey Juan Carlos and Carlos III of Madrid, the Autonomous University of Barcelona, the universities of Cantabria, León and Castilla la Mancha, the Superior Council of Scientific Research through the Astrophysics Institute of Andalucía and the foundations Robotiker Tecnalia, Center of Aeronautical Technologies and Innaxis Research Institute. Additionally, the ATLANTIDA consortium includes the collaboration of Tecnobit, a defense company specialized in avionics hardware of high integration level.