Deep-sea mapping by a swarm of autonomous vehicles

Pictorial representation of Aggronauts — © Fraunhofer IOSB

Water Strider Structure — © Fraunhofer IOSB
Setting up a Water Strider during the competition final in Kalamata, Greece.

Diving Drone Water Strider — © Fraunhofer IOSB
One of the diving drones on the water surface

Short description of the project

Behind the project name "Arggonauts" lies the development of unnamed, autonomous submersibles. For this purpose, the Fraunhofer IOSB team presented five unmanned surface vehicles based on inflatable catamarans, so-called "Water Striders", as well as 2.60 metre long diving drones, nicknamed "Great Drivers", as part of the worldwide technology competition for deep-sea mapping "Shell Ocean Dicovery XPrice". The electrically powered catamarans can transport the submarines, which are also electrically powered, to an operation site up to 90km from land, where the "Great Drivers" descend independently. Here, the Great Divers survey the seabed by communicating with the surface vehicles via sound waves. The Water Drivers, in turn, obtain their information from GPS signals from space, which they convert into acoustic signals. The submersibles use these signals to orient themselves and navigate the geo-position. The seabed is scanned by means of a high-resolution sonar from a distance of about 80 metres.

Project goals

To date, only about 5 per cent of the deep sea (the oceans beyond a depth of 1000 metres) has been explored, despite the fact that over 60 per cent of the Earth is covered by water that has an impact on our lives. In the oceans, CO2 and methane hydrate are released and stored, and submarine trenches, canyons, hills and mountain peaks affect the course of currents. The research vessels used so far have the disadvantage of being large, cumbersome, dependent on human crews and therefore costly. The aim of the project is therefore to map the seabed in high resolution using a low-cost and autonomous technology. The extended benefits of a technology like Arggonauts are research into the impact of the deep sea on the CO2 budget as well as environmental and species protection.

Project outcome

The Arggonauts team at Fraunhofer IOSB has succeeded in developing tandems of lightweight autonomous surface vehicles and torpedo-shaped diving drones that operate in a swarm. This development made it possible to carry out high-resolution surveys of the ocean floor at a depth of 4000 metres and to take photos of objects such as shipwrecks. The successful participation in the Shell Ocean Discovery XPRIZE research competition (2016-2018) was an important milestone in the field of mobile, autonomous systems in hostile environments. The "Arggonauts" were the only German team out of 32 to make it into the top five.

TV programme Terra X features Team ARGGONAUTS

The programme "Terra X: Measuring the Earth" from April 4, 2019 reports on the ARGGONAUTS project of Fraunhofer IOSB from minute 20.

Go to video

Detailed information

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Underwater vehicles

Underwater vehicle "Great Diver"

Can navigate autonomously
Position determination by means of sonar signals from the surface vehicles
Weight: 350 kg
Length: 260 cm
Diameter: 57 cm
Motor power: 370 watts
Speed: 8 km/h

The design is open: The interior of the submarine is filled with water. Buoyancy is provided by the outer skin made of pure polypropylene. A large part of the electronics is embedded in silicone rubber in a pressure-neutral manner. Only a few components are not pressure-resistant, as they are located in a titanium tube. Thus, despite its compact design and low weight, the Great Diver is suitable for the extreme pressure in the deep sea (up to 400 bar).

Surface Vehicle

Oberflächenfahrzeug Water Strider — © Fraunhofer IOSB / Eduard Maydanik
Test mission near Laredo off the coast of Spain: a Water Strider traveling autonomously.

Surface vehicle "Water Strider"

Inflatable catamaran (2 air chambers)
For transporting and recovering the Great Divers (the latter via a specially developed and patent-pending recovery manoeuvre) and for communicating with the submersibles (see graphic below)
Navigates autonomously as well
Weight: approx. 500 kg (when fully operational)
Length: 594 cm
Width: 287 cm
Motor power: 10 hp (= 7355 watts)

There are five tandems in operation, each consisting of a Water Strider and a Great Diver. One of the Great Divers has a high-performance LED flash system and specially developed photo cameras on board.

Team

Arggonauts group photo — © Fraunhofer IOSB
The team during the competition final in Greece.

The ARGGONAUTS team

17 people
7 nations
Site: Fraunhofer IOSB, Karlsruhe

Competition

The competition

The Shell Ocean Discovery XPRIZE, launched in late 2015, was a three-year research competition. It aimed to promote the development of maritime technologies and advance autonomous, rapid and high-resolution exploration of the deep sea. The competition was funded by Shell. It was organised by the non-profit XPRIZE Foundation, which has launched other science and technology competitions to promote innovative ideas and technologies. The foundation was founded in 1995 by the American aeronautical engineer Peter Diamandis.

In 2016, 32 teams entered the Shell Ocean Discovery XPRIZE. Twenty-one of them qualified for the semi-finals. Nine teams met the criteria and thus qualified for the final.

In the final, the teams had to fulfil the following tasks:

The developed systems had to be launched from shore, autonomously perform a reconnaissance mission to collect data and also autonomously return to port.
At least 50 per cent of the discharge area, which is 500 km² in size and lies at depths of up to 4000 metres, had to be mapped.
Resolution of the generated 3D map: 5 metres horizontally, 50 cm vertically.
Time limit: 24 hours for data collection, 48 hours for return transport and data analysis
Slim equipment: All the equipment used had to fit into a standard ISO container

In addition, it was required that the systems could demonstrably generate underwater images. The task was to find and photograph the XPRIZE Ocean Trophy - in a delimited sub-area at a depth of 4000 metres. Bonus points were awarded for photos of other biological, geological or archaeological features.

Final venue

The starting point was the port of Kalamata in Greece. There, in the so-called Ionian Basin, is the Calypso Deep, where the Mediterranean Sea is more than 5,000 metres deep in places.

Name and logo

History of the name Arggonauts — © Pixabay

Background on the project name

The name comes from the Argonaut saga: The Argonauts (with a g) were a group of Greek heroes (including Heracles (Latin Hercules), Orpheus and Theseus, son of Poseidon) who went in search of the Golden Fleece for their leader Jason. They were named after their ship Argo, which was built by Argos. They travelled from Greece through the Aegean and the Black Sea to what is now Georgia, to Kyta (now Poti). Conquering oceans, facing the dangers of the sea and experiencing adventure - this is what connects the ARGGONAUTS with the Argonauts.

The development of the logo

In their logo, the ARGGONAUTS use the ancient constellation Argo Navis (ship Argo), which represents the ship from the Argonaut saga. Today, this constellation is no longer in use. It was composed of today's constellations Carina ("keel of the ship"), Puppis ("stern deck of the ship") and Vela ("sails of the ship").

Focus topic maritime technologies

Our expertise in autonomous mobile systems as well as in data and image exploitation enables us to develop diverse solutions on, under and above the water. On the focus topic page, you can learn more about our specific research topics and projects and find out which IOSB departments and sites are involved.

Maritime technologies

visIT "Mobile robot systems"

This issue of Fraunhofer IOSB's visIT topic brochure focuses on approaches that increase the degree of autonomy of robotic systems. Several of the articles deal with the XPRIZE project and the field of autonomous maritime systems.

To the ePaper of the visIT issue

Media response

During its duration (2015-2019), Fraunhofer IOSB's activities within the Shell Ocean Discovery XPRIZE were reflected in a variety of media channels. Here is a selection: