ATLAS ELEKTRONIK and the GREX-Project: Co-ordination and Control of Co-operating Unmanned Systems

Today scientific and military users demand systems composed of multiple underwater vehicles. In such a swarm each vehicle plays the role of a sophisticated node with sensor, processing and communication capabilities within a network - thus combining the properties of heterogeneous systems in a team. "GREX� - the Latin word for a herd or flock - indicates the focus of a European research project which started in June 2006. The major goal is the creation of a conceptual framework and middleware to coordinate a flock of heterogeneous unmanned marine vehicles in order to achieve their mission goal in an optimised manner.

Currently the exploitation of Unmanned Underwater Vehicles (UUVs) is under rapid development. For many navies one shot mine disposal vehicles are becoming standard, first Autonomous Underwater Vehicles (AUVs) are introduced for remote sensing such as exploratory/reconnaissance operations to name only two examples. Modern concepts of naval mine warfare introduce ships with a variety of different UUVs which might be deployed at the same time. The resulting requirements are that the management of a group of heterogeneous vehicles will be essential for the future mine warfare theatre.

Similar needs come from the civil community: offshore geologists, marine researchers or underwater archaeologists could benefit from the use of multiple vehicles. They allow surveying wider areas in less time, simultaneously obtaining time and space resolutions that are otherwise unachievable. Combining pre-existing vehicles into a team will make research more effective and will lead to completely new applications.

To coordinate and handle such groups of vehicles the research project GREX has been created within the 6th framework of the European Commission. The three years project started in June 2006 and will end in June 2009. The Consortium is composed of 9 Partners which share the work under coordination of the German company ATLAS ELEKTRONIK GmbH. GREX started with a short definition phase. The Instituto do Mar at the University of the Azores, which is dedicated to biological research in the underwater domain, is in charge to define scenarios and requirements, from which development and trials will be deducted. Scientific Methodical Analysis and Research are mainly be performed by the Institute of Robotics of the Instituto Superior Técnico (IST) (Portugal) and the Technische Universität Ilmenau, Faculty of Computer Science and Automation in Germany. Both Institutes combine their theoretical backgrounds to achieve the ambitious goals.

The Bulgarian SME Sciant, experts in embedded systems and communications, develops the middleware for inter-process and inter-vehicle communication as well as for dynamic networking.

The French research institute Ifremer with its operational experience in underwater communication leads the specifications of communication in the GREX system and provides their AsterX-Vehicle for evaluative tests. To test the functionality of the joint modules, an overall simulation is developed by Seebyte Ltd.,UK. They are also responsible to create the GUI for planning and analysis of the coordinated mission. The scientific/technical part of the project, described above, is framed by an intensive marketing.

INNOVA uses their experience in market studies and exploitation plans for GREX. MC Marketing Consulting coordinates the dissemination and promotion during the project and prepares the web presentation. (http://www.grex-project.eu).
The main goal of the project is to achieve a first level of distributed "intelligence� through dependable embedded systems that are interconnected and cooperate towards the coordinated execution of tasks.

Thus the project will witness the development of theoretical methods and practical tools for multiple vehicle cooperation, bridging the gap between concept and practice. The technology developed must be on one hand sufficiently generic in order to interface pre-existing heterogeneous systems. On the other hand it must be sufficiently robust to cover problems caused by faulty communications. The objectives of the GREX project are well rooted in an in-depth analysis of potential user requirements. There are three types of mission scenarios which are the basis for discussion and specifications. These mission scenarios envisioned take into account challenging problems in the field of marine science. Scenario 1 is the quest for hydrothermal vents, scenario 2 deals with download data from tagged fish and scenario 3 addresses marine habitat mapping.

The project is divided into three major phases which are characterized by the main activities:

1. Specifications and scientific research,
2. Applied research and implementation,
3. Successive trials and final demonstration of results

Currently the project approaches the end of the first phase. Most specifications are finalized and research on the challenging topics is in full progress. Beneath methodical research, hardware tests are performed which includes e. g. trials of different acoustic underwater modems. Furthermore, a system simulator is under development which allows testing various software items during the coming development.

The final result will comprise a user interface, based on the SeeTrack software, a common control system for coordinated mission execution and control, a team based navigation system and a sophisticated communication system which takes into account needs for dynamic networking. All control and navigation issues have to be realized under constraints of the challenging underwater environment which allows only sparse communication. At the end of the project in 2009, life sea trials will be performed to validate the results achieved.