Unmanned Systems Technology 025 | iXblue DriX I Maintenance I UGVs I IDEX 2019 I Planck Aero Shearwater I Sky Power hybrid system I Delph Dynamics RH4 I GCSs I StreetDrone Twizy I Oceanology Americas 2019

22 H aving a job to do but not quite the right tool with which to do it is the situation that iXblue faced three years ago when the maritime survey division of this navigation, positioning and imaging company was competing for a contract from the New Zealand Hydrographic Service (NZHS) to map the seabed around Tonga, in the South Pacific. It did not have the equipment that would allow it to match the day rates offered by the big survey companies against whom it was bidding, so it decided to look for an off-the-shelf unmanned solution that could be launched from and recovered by a mother ship. “We benchmarked a number of USVs, and while we were doing that we found a number of things we didn’t like,” says Guillaume Eudeline, business development manager for the company’s Shipyard division. “First of all, they were very slow, and they all had either V-shaped monohulls or catamaran hulls. They simply did not handle the sea correctly.” Their motion over the waves, he says, limited their potential usefulness because it would degrade the performance of the sensors. Unable to find a vehicle that met their needs, they therefore decided to develop one themselves that would draw on in-house capabilities and experience. This experience included a USV built for the French Navy to tow targets and monitor missile launches; it was iXblue’s first autonomous vehicle. Fast forward to 2016, and the NZHS was sufficiently impressed with the DriX for iXblue to win the Tonga contract, which it completed at the end of 2018. Displacing 1.4 tonnes, the DriX’s development was led by iXblue’s Shipyard director Sebastien Grall. His engineering team had to find ways to minimise any interference with the sensors from bubbles, vibration and the vehicle’s own radiated noise. “The benchmarking we did of other USVs helped us considerably, because all the flaws we noticed when we conducted those trials were in reality the beginning of our development. We wanted to make sure the DriX had none Minimising noise and vibration are key to this USV’s success, writes Peter Donaldson , who explains how it was developed April/May 2019 | Unmanned Systems Technology The DriX carrying out the contract to survey the seabed around the Tonga archipelago for which iXblue developed the vehicle (Courtesy of iXblue) The high fineness ratio that minimises drag, the wave- piercing reverse bow, the drop keel and the sensor gondola it supports are all intended to promote stability in the pitch, yaw and roll axes (Courtesy of iXblue)