Unmanned Systems Technology 023 I Milrem Multiscope I Wireless charging I Logistics insight I InterGeo, CUAV London & USA show reports I VideoRay Defender I OS Engines GR400U-FI I Ultrabeam Hydrographic Ultra-2 I IMUs

70 I n the pursuit of more accurate and detailed data about marine assets, a hydrographer’s first instinct may simply be to source a more powerful sensor for their survey vessel. For British start-up Ultrabeam Hydrographic, however, that approach was not enough. A certain dissatisfaction with the architectures of existing survey USVs has prompted the company to develop its own unmanned hydrography platforms. These share a novel propulsion configuration, originally inspired by observations of a quadcopter UAV Ultrabeam had used that had been designed around better motion control and stability than other craft – specifically, its ability to hold its position even in a strong and gusty wind. That, according to the company's technical director Gabriel Walton, enables its Ultra series of USVs to conduct hydrographic surveys in a far more reliable and repeatable manner than is possible with typical hydrography USVs. Position-keeping “In most USVs, the propulsion layout is the same as on a manned boat, only smaller: one or two outboard motors on the stern,” Walton observes. “But we aren’t vessel builders, we’re hydrographers. We therefore have a close understanding of the kind of variables affecting our data collection. “We used that to design our own USVs, rather than going to a manufacturer and asking them to draw what they think we ought to have according to their approach to USV design. “Riverine environments around bridges often have a constant current. Navigating them using manned boats is challenging enough, and you need to maintain your heading for optimal data capture, which is very difficult,” he explains. “Manned boats can typically only do this by ‘crabbing’ into the current – pointing the bow upstream – maybe even by as much as 45°.” Also, with gusts of wind around bridges sometimes reaching 80 kph, manned boats can be put at risk from sudden changes in wind direction, increasing the survey times and costs significantly. Existing survey USVs not good enough? Then do what this company did, and build your own. Rory Jackson reports Ports of call December/January 2019 | Unmanned Systems Technology Ultrabeam Hydrographic’s USV uses four vectored thrusters to minimise the vessel’s movements amidst waves, to output clear, precise sonar and lidar imagery (Images courtesy of Ultrabeam Hydrographic)