Unmanned Systems Technology 022 | XOcean XO-450 l Radar systems l Space vehicles insight l Small Robot l BMPower FCPS l Prismatic HALE UAV l InterDrone 2018 show report l UpVision l Navigation systems

30 high-end off-the-shelf components. These include a weather station, a GNSS receiver and antenna, a triducer that measures speed through the water plus depth under the keel and water temperature, inertial sensors and sound velocity profiling devices. Comms hardware includes satcom, a short-range UHF radio that works with a hand controller, and a wi-fi router. There are also four daylight TV cameras, a steerable IR camera, an active radar target enhancer, a foghorn, a microphone and lighting, in addition to a power management system and sensor interfaces. The system also includes a central computer – again subordinate to the PLC – that runs both Windows and Linux operating systems to support the software that comes with different sensors. It also manages the recording of sensor data onto the removable hard drive. Each survey sensor also comes with internal as well as external hardware, which must be accommodated in payload bays in the hulls or the pod, and must interface with the power supply, the PLC and the central computer. Integration effort Ives says the main engineering challenge in the development programme has been integrating all these components and subsystems. The approach they took was to test all the systems off the boat first, connecting them up on the bench and making sure they could communicate with each other before moving on to the next system. Once powered and connected to the network, each of the 30 or so systems had to be persuaded to talk to the PLC, a task that involved establishing which protocol it was running and translating it. “Some of them took an afternoon to do; some of them a week or so,” Ives notes. The thrusters are a good example, he adds. “It took us a while to understand the architecture of the system and the comms to it, but as soon as we understood it we got it working in an afternoon.” Despite the different and unpredictable levels of effort involved in integrating each system, none proved a particular stumbling October/November 2018 | Unmanned Systems Technology Length: 4.5 m Beam: 2.2 m Height: 2.2 m Weight: 750 kg Payload: 100 kg Hull type: glass fibre-reinforced plastic composite wave-piercing catamaran Hybrid power system: diesel generator, solar deck, lithium-polymer batteries Continuous electrical load: 1.05 kW Propulsion: two x DC, fixed reversible pod drives Steering: differential thrust Speed: 3.5 knots in normal operation, 7 knots in transit between survey areas Endurance: 18 days Range: 1512 nautical miles Comms: over-the-horizon via satcom, UHF radio for local remote control, wi-fi for maintenance and configuration Networking: Ethernet, National Marine Electronics Association network, serial Collision avoidance: automatic identification system, thermal imaging and daylight TV cameras Transport: road trailer or shipping container Some key suppliers Weather station: Airmar Programmable logic controller: Allen-Bradley Satcom hardware: Cobham Radar target enhancer: Echomax Steerable EO/IR camera pod: FLIR Systems GNSS: Garmin Control interface: in-house Trailer: Indespension (customised in-house) Satcom services: Inmarsat Satcom services: Iridium Motion reference unit: Kongsberg Daylight TV cameras: Iris Innovations Electrical power supply and management system: Mastervolt Hull construction: MB Yachts Fish-finding sonar: Simrad Diesel generator: Yanmar Data sheet XOcean’s safety boat escorts the first XO-450 prototype into the marina at Carlingford, with the USV under manual remote control from a handset (Author’s image)