Thales has teamed up with 19 high-tech startups to develop the AUSS autonomous underwater and surface system, a concept that is set to reshape autonomous operations at sea.

Surveillance, intelligence, counter-terrorism, mine countermeasures, anti-submarine warfare, monitoring of offshore infrastructure, and shipwreck search & recovery are among the applications envisaged for the new concept now being developed by Thales’s underwater systems business and 19 French small and medium-size enterprises. A potential game-changer, this hybrid autonomous underwater system will be equipped not only for underwater missions, but also for surface intelligence, surveillance and reconnaissance, or ISR. For over three years, Thales and its partners have been quietly developing the basic concept and its underlying innovations.

More capable than an AUV

The proposal to call the concept an ‘autonomous underwater and surface system’ is partly due to the difficulty the team had in describing it in just a few words. AUSS aims to overcome the shortcomings of current-generation AUVs. “Over the last decade or so we’ve done a lot of work on AUVs for mine countermeasures. This time, we wanted to develop a more capable autonomous system for a broader range of missions,” says Jean-François Ghignoni, Director of Marketing & Strategy, Thales Underwater Systems. “Today’s AUVs suffer from several limitations. First, they cannot stop. Second, they can only avoid obstacles by manoeuvring while maintaining speed. More generally, attitude control is ensured by maintaining relative motion between the control surfaces and the surrounding water. In other words, whether under water or close to the surface, they are not very agile. Note too that the only current-generation AUVs capable of raising a sensor mast weigh 5 tonnes or more.”

AUSS (© Thales)

ISR, the main game

The AUSS concept was initially developed to meet a range of ISR needs. While AUVs have proven their worth for MCM, they are ill-suited to surface ISR. First, their behaviour when floating or close to the surface is difficult to model; second, their stability depends on the sea state. There is, however, growing demand for ISR drones that can be launched from the shore, from surface vessels, or, in future, from submarines. Standoff ISR drones will significantly improve a submarine’s tactical situation awareness and surveillance capabilities without compromising its discretion; in other words, without exposing the boat or its crew to unnecessary risk.

Light, stable and agile

Considerations such as these suggested that the platform should be relatively light — say 500 to 1000kg, depending on the payload — as well as stable, agile, and able to manoeuvre in confined spaces. It should feature a deployable mast carrying a range of sensors including a radar, electro-optical devices, Sigint interceptors and antennas for radio and/or satellite communications. It should also be stable in moderate seas and offer good endurance along with the ability to evade threats. “The aim then was to design a platform combining all these features yet weighing less than a tonne. It would also have to be able to remain stationary, or on station, in the presence of strong currents, move or remain on station close to the surface, and, while stationary, deploy a 3-metre mast,” says Jean-François Ghignoni. While AUVs continue to improve, all are based on the same operating principles with the same inherent limitations. Thales saw a need and an opportunity to aim for a disruptive technology.

A mandate to think outside the box

To address the challenge, Thales and its partners decided to go back to basics and explore alternative approaches. “To promote innovation, we began by giving the team an explicit mandate to think outside the box, to get off the beaten track and to come up with new solutions meeting our needs. It was an exhilarating experience. The SMEs came up with a host of innovative ideas resulting in the AUSS concept; a clever combination of an AUV and an unmanned surface vehicle, or USV.

Five sea trial campaigns completed

Design work began in 2013 and the first series of sea trials was conducted the following year off Brest. Since then, four more campaigns have been conducted to validate the basic concept and evaluate the platform’s performance for different mission profiles.

AUSS (© Thales)

The importance of industrial design

The prototype AUSS is 5.5 metres long, 53cm in diameter and weighs around 600 kilos. Initially it looked like a torpedo. The current version looks somewhat different, firstly because the team wanted to ensure that it was clearly distinguishable from a conventional AUV. In fact, Thales asked an industrial designer to give the AUSS a different look. The engineering teams saw this essentially as a marketing ploy, until, contrary to all expectations, they realised that the new design would have a significant operational benefits. “When we called in Concept Frenoy Design, we initially asked them to make the AUSS more visually appealing than a simple tube. The industrial design team submitted a number of proposals. On examining them, the project’s scientific director was surprised to see that some of the proposed shapes offered better performance than the simple tube!

AUSS (© Thales)

Like an underwater helicopter

Hydrodynamically efficient thanks to the absence of control surfaces, the platform is powered by contrarotating propellers and surprisingly agile. “The AUSS advances discreetly to its designated area of operation with its obstacle avoidance system activated. Should it encounter an obstacle, the combined propulsion and manoeuvring system enables it to stop, then ascend or descend vertically rather than having to manoeuvre while maintaining speed like an AUV. To put it in a nutshell, an AUSS drone behaves like a helicopter whereas AUVs behave like a fixed-wing aircraft. The AUSS can, for instance, come to a complete stop in about 10 metres.”

AUSS drone in surface ISR mode (© Thales)

Standing tall, mast up

Another innovation is the centre-of-gravity control system, a closely guarded Thales secret that enables the AUSS to adopt any attitude in a limited volume of water. “The concept was first validated in the Thales 20mx8m test tank at Brest, then at sea by making the platform move through 360° while remaining within a cubic volume just 8m on a side.” Thanks to this new approach to mass and centre-of-gravity control, the AUSS can remain upright and on station. This breakthrough is the result of many tests exploring a number of ideas. “To achieve this paradigm shift, we had to think way outside the box,” says Jean-François Ghignoni. “For ISR missions, the platform needs to stand upright with its nose close to the surface and its sensor mast protruding. Keeping the hull below the surface improves stability by limiting the impact of wave action.” If an AUSS drone on an operational ISR mission deploys its panoramic sensors and identifies a threat or intrusion likely to betray its presence, it retracts its mast and retreats to deeper water. Then, when the danger has passed, it automatically resumes its mission where it left off.

AUSS drone in surface ISR mode (© Thales)

AUSS mockup at Euronaval 2016 (© Thales)

Two weeks at sea

On completing an operational ISR phase, the drone rotates to a horizontal attitude and proceeds with its mission profile. One option is to have it sink to the seafloor, deploy an anchor, then wait for a given time or event in a low-energy state. Several innovative technologies contribute to the drone’s optimal operational potential and low power consumption. “To give just one example, efficient mass control means efficient buoyancy control, which in turn ensures that the drone consumes very little power while stationary.” The end result is significantly improved endurance. The Thales designers aim to achieve two weeks’ endurance, a range of 50nm and a maximum speed of 20 knots. The prototype already achieved 17 knots during sea trials. “The high dash speed will enable the AUSS to escape threats, deploy rapidly and trail fast targets,” says Jean-François Ghignoni.

Excellent results

Thales chose not to publish the videos recorded during the five test campaigns conducted off Brest in 2016. Journalists who were allowed to see the footage confirm that the prototype’s behaviour corresponds broadly to that shown in the demonstration video. The platform’s agility is impressive, as it can rotate to the vertical, deploy its mast and record imagery with surprising stability up to sea state 3 without a sensor stabilisation system.

These capabilities are precisely those required for ISR missions where discretion and endurance are vital. This is not, however, the only area in which the AUSS concept is expected to excel. “The aim, from the outset, was to design a multimission platform. Now that the basic concept has been validated, we plan to talk to clients about tailoring it to their operational needs.”

Counter-terrorism

AUSS drones are expected to prove particularly useful in maritime counter-terrorism. An AUSS drone could, for instance, surveil a hijacked vessel or facility from relatively close range using a variety of sensors (TV/IR camera, eavesdropping systems, etc.) enabling the authorities to monitor the situation in real time. The drone could also, presumably, be equipped with jammers to cut off communications between the hijackers and the outside world and to incapacitate the vessel’s radar, thereby giving a commando team an opportunity to board and take control.

AUSS drone in MCM mode (© Thales)

Mine countermeasures

Although the AUSS drone was not designed primarily for mine countermeasures, it nevertheless looks very promising for MCM missions. First, the hull can accommodate Thales’s Samdis side-scan sonar; a type already used by dedicated MCM AUVs. The nose section can also be equipped with various payloads, including a camera and projector for mine identification. The AUSS drone’s agility is an important advantage as it can manoeuvre to record images of an object of interest from various angles. “We believe that the AUSS drone could be readily repurposed for MCM to offer higher performance than existing MCM AUVs, particularly as regards its stability and ability to operate in the presence of strong currents,” says Jean-François Ghignoni.

AUSS drone in MCM mode (© Thales)

Surveillance of offshore infrastructure

Turning to the civil sector, one application that has attracted attention is in offshore oil & gas where AUSS drones could be used to monitor seabed equipment. “This work is currently performed by vessels equipped with remotely operated vehicles. These vessels and their ROVs are, however, both costly and labour intensive. An AUSS drone could leave a port under its own power, transit to an offshore oil or gas field, then autonomously monitor kilometres of seabed piping and associated equipment while periodically transmitting imagery via, say, a satellite link to a shore-based control centre. This would significantly reduce the cost of monitoring seabed infrastructure.”

AUSS drone in seabed surveillance mode (© Thales)

A concept with enormous potential

Given its modular design and adaptability to a wide range of operating constraints and needs, the potential applications for AUSS drones are enormous. “Operational personnel who have seen our presentations have been amazed by the drone’s capabilities and consider that the concept has great potential,” says Jean-François Ghignoni. “While we have already validated the feasibility of some applications, many others have still to be explored. For the moment, we have only made public a small proportion of what AUSS drones will be capable of. We are still a long way from measuring the full impact of their unprecedented agility and performance.”

Sonar barrage

One of the many disruptions to established operational procedures could be in anti-submarine warfare. With the number of submarines in operation rising rapidly and many countries lacking the means to detect their presence, suitably equipped AUSS drones could be deployed as sonar stations with capabilities similar to those of large sonobuoys, or, alternatively, in groups to form mobile or even permanent acoustic barrages protecting harbours, maritime approaches and other sensitive areas.

Discussions under way

After years spent improving existing concepts for autonomous underwater systems, the AUSS is expected to prove truly disruptive on both the technological and operational fronts. Time will tell. For the moment, all Thales will say is that the concept is attracting enormous interest and that discussions are in progress with various navies impressed by its potential.

Towards a new cluster

After spending millions of euros on company-funded R&D on this project, Thales now aims to establish itself as a world leader in the field. “The operational prospects are huge and we have what it takes to offer better solutions than our competitors,” says Jean-François Ghignoni, who hopes to see a new field of French excellence emerge. “We hope that the SMEs that helped us to develop the concept thus far will start exporting and indeed that the project acts as a pole for French companies active in AUVs in general. We are already talking to our partners about setting up a new export-focussed AUSS cluster.”

Asked whether Thales could end up competing head on with established French leaders, Jean-François Ghignoni replied: “We do not aim to compete with French companies producing MCM AUVs. The AUSS concept is a truly multimission one. Navies that choose to acquire AUSS drones are unlikely to do so primarily to conduct MCM missions for which AUVs already offer satisfactory performance. The first applications will be for ISR, counter-terrorism or the surveillance of offshore infrastructure.” Even so, some clients clearly may be tempted to reduce overall acquisition, maintenance and training costs by using AUSS drones in multiple roles.

Original, in French, by Vincent Groizeleau, translated and adapted by Steve Dyson