Unmanned Systems Technology 016 | Hydromea Vertex AUV | Power management systems | Unmanned Space Vehicles | Continental CD-155 turbodiesel | Swift 020 UAV | ECUs | DSEI 2017 Show report

21 S ometimes, bringing new technology to market obliges its developer not only to create and nurture it but also to demonstrate it by providing the new services that the technology enables. Alexander Bahr and Felix Schill, principals of Swiss start-up Hydromea, are in this position with their miniature (7 kg) Vertex AUV, which they plan to operate in swarms of 20 or more in water sampling missions to collect data at very high densities down to depths of about 300 m. Marine engineers with PhDs in underwater localisation and communications respectively, Bahr and Schill have been developing the Vertex through a partnership with the École Polytechnique Fédérale de Lausanne (EPFL), a university and research institute based in Switzerland. They formed Hydromea as a commercial spin-off to exploit the AUV as a whole and, along the way, some of the component technologies they have developed for it. Measuring just 70 cm long, Vertex is designed for missions in which remote sensing is impractical because the sensors must be physically present in the medium they are sampling, to measure the parameters in which the researchers are interested. These include conductivity, temperature and depth (CTD), biological parameters such as chlorophyll content and dissolved gases such as oxygen, Schill says. “It’s for where you can only take the measurement exactly where the sensor is – in that cubic centimetre of water. No matter how powerful your vehicle is, you are only going to obtain that one measurement at one point in time and space,” he explains. “If you want a 3D snapshot of something like a plume or a spill, or spatial phenomena like layering – especially things that can change over time – the only way to do it is to have lots of robots with lots of sensors in different places that can coordinate and adapt their behaviour to follow features.” The vision is to create groups of vehicles that interact and that know where they are with respect to the formation of the rest of the group under water so that they can coordinate as a swarm at short distances and build a high-resolution picture. Typically 10 to 50 m apart, they would cover an area ranging from a few hundred square metres to few square kilometres over a six- to eight-hour working day, and managed by one or two people. Size matters The toughest engineering challenges Bahr and Schill had to overcome were all connected with size. “Size matters a lot when you want to make a small and fully capable AUV,” Bahr notes. “In the marine industry, everything is made for big, manly hands – the connectors, the pressure vessels, the bulkheads, everything is big. So we learnt the hard way that the moment you start to make something this size with all the capabilities you want, you have to pretty much make everything from scratch. “Or look very hard – even for something as simple as underwater connectors,” Schill adds. “The first time we went to a trade show asking people for small underwater connectors they showed us things the size of a fist and a quarter the size of the vehicle we wanted to build!” Bahr says they eventually found connectors small enough from Lemo, which is better known for its professional audiovisual connectors but also has a range of underwater units. For a long time, it was payloads that set the practical minimum for AUV size, as Schill explains. “Making a vehicle small is one thing, but if you cannot put the payloads on it, it’s too small.” Hydromea Vertex AUV | Dossier Unmanned Systems Technology | October/November 2017