Ring wing allows tight manoeuvring

The RingWing is a unmanned underwater vehicle in the form of an annular, sculpted wing, instead of the more conventional torpedo shape. This allows it to turn on the spot or glide under no power. The idea has been conceived by a team led by Harry Gosling, who have named their business GO Science. The company is based in a technology centre in the University of Bristol. Manoeuvring is achieved by having two thrusters inside the ring, which allow it to perform static turns or roll. It is radio controlled, but includes a built-in computer to allow it to undertake autonomous missions. Apart from the thrusters, all the batteries, control electronics and other hardware are housed within the thickness of the wing. It presently exists in the form of a working prototype, 481mm in diameter and 0.6m long, which was demonstrated at the recent Unmanned Underwater Vehicle Showcase at the National Oceanography Centre in Southampton. Gosling said the design had been tested in ‘pools, quarries and lakes’, with the next stage being harbour testing. Gosling added: “Wing rings are notoriously difficult to control – there are some ring winged UAVs [unmanned aerial vehicles], but not with twin thrust propulsors.” Although the prototype has a foam core and, to prevent possible crush damage, drives itself up to the surface if it goes deeper than 20m, Gosling said: “We are moving into a program of test and evaluation with an offshore customer.” The project, which began in 2003, is being assisted by a UK government grant, as well as an EPSRC grant relating to collision avoidance sensor work. GO Science engineer Roman Kingsland added: “It has a lot lower drag than other vehicles and a very good glide path.” Conventional torpedo shaped underwater vehicles tend to have to be kept under power if they are not to sink. They also take a while to turn. According to Kingsland, the intention is to keep the vehicle very low cost and that one of the goals is to enable swarms of the devices to operate just above the sea bed to undertake oil and gas exploration. The vehicles would gather sensor data in their loggers until told to return and unload it. Another target application is asset inspection, although the machines could also be used for harbour protection, intruder classification, hull inspection, environmental monitoring and adaptive sensor and adaptive communication networks. The platform can support temperature, heading, acoustic, seismic, infra red and video sensors. Gosling says the prototype has two 2kW rated ‘off the shelf’ thrusters, with custom motors and shaft seals. Power is delivered by 1.1 kWh capacity lithium polymer batteries. Gosling says the next generation of RingWings will have pressure balanced, sealed motors, a buoyancy control system and be able to dive deeper. Pointers * Ring winged UAV is able to turn on the spot and manoeuvre in very tight places * Drag is much lower than for conventional torpedo shaped vehicles and it can also glide under low power, reducing energy consumption * The idea presently exists in the form of a working prototype.