Unmanned Systems Technology 028 | ecoSUB Robotics AUVs I ECUs focus I Space vehicles insight I AMZ Driverless gotthard I InterDrone 2019 report I ATI WAM 167-BB I Video systems focus I Aerdron HL4 Herculift

30 Dossier | ecoSUB Robotics AUVs gets around a limitation of Iridium that forces operators to send information to and from remote objects such as AUVs via the internet. “We had to figure out a way of fooling the satellite into thinking Hermes is a sub,” Sloane says. “Now we can send messages directly from anywhere in the world to the sub, and from the sub directly to us.” All the vehicles are small enough to be launched by hand, while the smallest can be dropped from aircraft, including small UAVs. To launch from ships with high sides, the company has developed a device that resembles a rope ladder, to the end of which the AUV is attached by cords with floats that lift them off their securing hooks when the vehicle enters the water. A boat hook is used for recovery, hooking through the duct of the smallest vehicle and a webbing strap on top of the larger ones. Materials and structure All ecoSUBs have basically the same anatomy. The pressure case is a tube made from 6082-T6 aluminium alloy machined to its final dimensions inside and out, and hard-anodised for corrosion protection. This material is more than strong enough at a reasonable thickness down to and far beyond the m25’s 2500 m depth rating. The company has proved this in the NOC’s test chamber, which can create the equivalent of 6000 m of water, Sloane says, having sacrificed four vehicles in this way. “We take it in stages to the working depth, then to at least 50% beyond, and then keep going until it goes bang. That’s quite exciting,” he says with a smile. He adds that ecoSUB Robotics has worked with a company based on the Isle of Wight, off the south coast of England, on some composite pressure case designs that could be used if the vehicles ever need to be made much lighter or stronger. The pressure case is completed by two end caps, onto which the nose and tail sections are fitted. It is sealed by dual O-rings at each end and a partial vacuum of 500 hPa (hectopascals), or half an atmosphere, that sucks them on. An internal pressure transducer is part of a suite of housekeeping sensors that also includes a humidity sensor. October/November 2019 | Unmanned Systems Technology The Hermes C3 system comes in a box that contains multiple RF and acoustic comms systems and enables direct comms with the AUV over Iridium without an internet connection (Courtesy of ecoSUB Robotics) Launching small AUVs from high- sided vessels can be tricky, so this rope harness with hooks that float free on water entry has been developed to solve the problem (Courtesy of ecoSUB Robotics) A pre-production prototype μ5 on the bench, revealing its electronics chassis, sliding battery pack, free-flooding nose cone and aluminium pressure case in the background (Author’s image)