By Paul Rincon
Science reporter, BBC News, Gosport
Underwater robot wars
At the edge of a vast indoor tank, a team of university students watches intensely as a robotic vehicle attempts to negotiate an underwater obstacle course.
The box-shaped robot, held in place within an outer frame, has been designed by a team from Heriot Watt University in Scotland.
It is designed to complete a series of challenging tasks: passing through a gate without touching any part of the structure, following a moving target, hovering over a stationary target and "parking" in a box.
But there is not a joystick in sight - this robot is designed to navigate the course independently of a human controller.
Heriot Watt's entry is one of eight autonomous underwater vehicles (AUVs) vying for top place in a competition called SAUC-E (Student Autonomous Underwater Challenge Europe).
The venue for this contest is the Ocean Basin in Gosport. This is Europe's largest freshwater tank, measuring 120m long, 60m wide and 5.5m deep.
2009 SAUC-E CONTEST RESULTS
1st Prize - Heriot Watt University (Team Nessie)
2nd Prize - ENSIETA
Innovation Prize - University of Lubeck (Hanse)
Run by defence research firm Qinetiq, it is mostly used to test models and prototypes of military ships and submarines.
When BBC News visited the facility, the student teams were competing in qualifying runs.
The rules of the SAUC-E competition stipulate that the robotic vehicles must perform their missions "with no control, guidance, or communication from a person, or from any off-board computer including GPS systems".
It is in this key respect that AUVs differ from the Remotely Operated Vehicles (ROVs), which have become indispensable in undersea exploration.
While ROVs are tethered to ships by a cable and controlled by an operator with a joystick, AUVs are guided by onboard artificial intelligence software.
David Burleigh, chief scientist for naval systems at the UK's Defence Science and Technology Laboratory (DSTL), which co-ordinates SAUC-E, told BBC News that autonomy was "a challenging technology".
"It's probably one of the most difficult aspects [to build into vehicles]," he says.
Team Nessie, from Heriot Watt, was the eventual winner
According to the experts, there are countless real-world applications - in industry and the military - for underwater robots that can operate independently of human control.
Nick Johnson, spokesman for Heriot Watt's Team Nessie, explains: "When you lay a cable under the sea, you have one ship laying the cable and another ship following it with an ROV which checks whether the cable is touching the sea floor.
"The ships cost about £10,000 a day each. So you could replace the second ship with an AUV. The fuel waste would go down, the cost would go down, it would be better for everyone."
Heriot Watt University's team won first prize in last year's competition, held in Brest, France, which made it one of the front runners this year. The Brest competition was carried out in sea water, which places distinct engineering pressures on the teams.
They emerged triumphant in the 2009 contest, with the most robust and effective system on the day in the eyes of competition judges.
A team from ENSIETA (Ecole Nationale Superieure des Ingenieurs des Etudes et Techniques d'Armement) in France took second place in the competition for their use of sonar in place of alternative systems.
The Ocean Basin holds six million gallons of water
"There is some prize money, but that's not really why we do it," says Nick Johnson.
"This technology is the kind of thing we do at the Ocean Systems Laboratory [at Heriot Watt University]. It's stressful, but lots of fun."
The Cambridge Autonomous Underwater Vehicle (CAUV) team has entered the competition three times, previously achieving second place.
Team spokesman Andy Pritchard says there is a friendly level of competition between the various teams.
There is some prize money, but that's not really why we do it
Nick Johnson, Team Nessie
Cambridge's sleek, torpedo-shaped vehicle has gone through several different iterations over the past few years.
"We have looked at software aspects, electronic aspects, how we can make things better, how we can make things more robust to compete in the competition," CAUV team member Justin Weng told BBC News.
"Over the past few years, we have grown from a team of about five people to about 15. But with more people, there is more management - how do you make sure that people do what they really want to do.
Some teams here today are new to the contest, such as the students from Lubeck University in Germany whose vehicle is called "Hanse".
Team member Christoph Osterloh told me their AUV had been put together over a period of just five months.
It carries a small laptop on board (protected in a waterproof casing) where other teams carry processors - a simpler and faster solution, the team believes.
The vehicle built at Lubeck carries a small laptop on board
And unlike other entries which use a type of propulsion motor designed specifically for underwater vehicles, the Lubeck team has opted to waterproof a type of motor that was not intended for immersion in water.
This has proven problematic and the team will probably use the other type in future.
Their vehicle did not perform as expected in the qualifier, several times turning in the opposite direction to the one it was expected to: "In the morning it worked and in the afternoon it did not," Christoph explains.
However, Lubeck University's AUV won the competition's innovation prize; Mr Osterloh says the team will be back next year with an improved vehicle.
Nick Johnson explains that building AUVs involves a "good combination" of electrical engineering and computer science know-how.
"In universities, the electrical engineers and the computer scientists don't always mix. But this breaks down the barriers - which is good," he tells me at Team Nessie's base.
"We have a couple of dedicated hardware engineers this year, and I'm a computer science guy. That means that I can concentrate on the software and not have to worry about the hardware."
DSTL set up the SAUC-E competition to challenge the skills and creativity of young engineers working on autonomous vehicles, fostering new ideas and talent in the process.
The contest also opens a channel for transferring the best ideas from academia to the military and industry.
"This is a European-wide, academic competition that has been going for four years. In recent times, it has been co-hosted with France," Dave Burleigh explains.
"It really is intended to capture bright ideas from our clever academic people in Europe. But it isn't just about trawling for new technical ideas. It's also about stimulating people and exciting people.
"Hopefully, we'll bring them into the fold, helping to solve some of our country's problems in future."
The competitors are faced with a tough underwater docking task
Mr Burleigh explains that the military wants autonomous underwater vehicles to tackle some of the most dangerous scenarios encountered during naval operations.
Sonar-equipped AUVs could be used for such purposes as mine clearance, as well as defending and patrolling harbours.
Indeed, the tasks on SAUC-E's underwater obstacle course have been designed to mimic some of the military uses to which an AUV might be put.
Nick Johnson explains: "The wall-tracking task vaguely reflects harbour defence. The ball-following task is pursuit, so if another sub infiltrates your harbour you follow it out again. The gates are navigation tasks and the docking box imitates offshore maintenance.
"If you've got an installation out in the sea, you send the AUV out. It goes and docks and carries out automatic maintenance."
Autonomous vehicles also release the work-rate burden on personnel: "If there is an element of human control to the mission, you might want to have the machine make as many of the decisions as it can," says David Burleigh.
The SAUC-E contest also provides student teams with the opportunity to evaluate their vehicles in one of Europe's premier maritime testing facilities.
The facility is well-suited to the underwater vehicle competition
The Ocean Basin allows ship and submarine models to be assessed in terms of their manoeuvrability, seakeeping, stability and controllability.
A wavemaker allows engineers to see how designs perform in rough waters and a rotating arm can be used to test the stability of submarines and other underwater vehicles.
"The Ocean Basin is bigger than a football pitch - by quite a way. It holds about six million gallons of fresh water," Phil Hardon, facility manager at Qinetiq's freshwater tank, tells me.
"Primarily we are here to support government work with submarines. So this autonomous submarine competition actually fits in very well with the sort of work we do in here."
Professor Peter Brett, from Aston University, is one of the judges of the SAUCE-E competition.
"It is a good educational exercise. Robotics in general is a wonderful design philosophy. It helps students to understand how to design in difficult environments, to provide good solutions using quite complex and sometimes state-of-the-art technology."
Nick Johnson comments: "A lot of things transfer between autonomous vehicles. So some of the technology we make could potentially go on an autonomous car, or on an autonomous plane. Once you get the waterproofing and the dynamics out of the way, a lot of the problems are quite similar."
Teams competing in the 2009 competition came from the University of Cambridge, University of Bath, University of the West of England, the University of Bremen, the University of Lubeck (both in Germany), Southampton University, Heriot Watt University and ENSIETA in France.
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