Unmanned Systems Technology 009 | Ocean Aero Submaran S10 | Simulation and testing | Farnborough report | 3W-110xi b2 TS HFE FI | USVs | Data storage | Eurosatory/UGS 2016 report

62 Insight | USVs Both survey vehicles can be monitored while under way, in auto or manual mode, while within line-of-sight range. The mission planner application runs on a base station laptop, connected through a radio telemetry link, and displays the vehicle’s position and progress against a background map of the survey area. Battery voltage, current and remaining capacity are monitored over this link, and it is also possible to switch from autonomous to remote control through a control system over a range of up to 2 km, with a survey endurance of more than eight miles on a single battery pack.  Skanska Construction in Norway is using the EchoBoat-ASV with AutoNav, Seafloor’s autopilot software that allows the company to pre-plan a survey, upload to the onboard memory and autonomously carry out a survey of the sea floor. The USV is equipped with a compact integrated wideband multi- beam sonar from Norbit that uses an internal inertial navigation system from NovaTel and integrated real-time sound velocity sensor from AML. The high-resolution image data from the sensors has either to be stored on board or sent to base for analysis, and this can be a major problem. Even if the craft has a satellite data link it may not have enough bandwidth to transfer high- quality 3D data, and that can reduce the craft’s range and endurance. Mine clearance Clearing mines in the sea is still a major challenge. For example, there are an estimated 80,000 mines in the Baltic that were left over from the two world wars, and some are still extremely dangerous. As recently as 2005, a mine killed three Dutch fishermen in the North Sea. Modern naval mines are made of composite materials in shapes designed to prevent detection by sonar systems, and can be buried by layers of sand, mud and silt. There are also ‘rising mines’ that wait in deep water for a ship to pass overhead, then ascend until in range to fire a torpedo. There are estimates of over 500,000 naval mines in military inventories around the world, so clearing these, and protecting against them, is a major focus. The CUSV that Textron is building for the UISS is 12 m long and can travel at speeds of up to 35 knots over a range of 2200 km and with an endurance of 48 hours. Twin diesels allow it to carry a 2300 kg payload or tow a 2000 kg mine detection and triggering system. “We are designing for modularity,” says Textron’s Prender. “The US Navy and commercial customers are interested in having multiple uses for the vehicles, so modularity for payloads and sensors on the vehicle is essential. In the unmanned world it’s all about payloads to collect data, whether it’s radar or sonar, so the important thing about the hull design is to reduce drag and improve performance. “We improved the design of the engine but also the drivetrain, adding stern drive technology for more manoeuvrability, and the control algorithms for that were part of the development phase.” The power for the control electronics and the payloads is generated by the diesel engines. “There is an element of battery back-up but that becomes payload-dependent,” he says. “Some payloads draw more energy than others, some may need power conversion, and that’s where a system may need its own batteries. But the diesels generate more than sufficient power for the payloads.” The craft is launched from a littoral combat ship (LCS) to detect, pinpoint and trigger mines under the surface. It does so by towing a Mk 104 minesweeping system that emits acoustic and magnetic signals that emulate the signature of a large vessel. The UISS will use a communications system aboard the LCS that is based around the AB3100H embedded computer from Ballard Technology. It comes with PCI mezzanine card modules that enable designers to add an Ethernet switch, synchronous and asynchronous serial interfaces and isolated double- throw relays. This acts as part of the command and control system for the USV. Up to 52 UISS craft are set to be built, with the first expected to be ready by December 2016. Israeli developer Elbit Systems has also developed a USV for anti-submarine operations and minesweeping, called Seagull, that has been demonstrated autonomously firing a torpedo for the first time. Seagull measures 12 m long, has a top speed of more than 30 knots and can carry a 2500 kg payload. It can be operated via a mission control system on the shore or other vessels at August/September 2016 | Unmanned Systems Technology The Seagull USV has been developed for anti- submarine operations and minesweeping, and has autonomously fired a torpedo for the first time