Unmanned Systems Technology 014 | Quantum Tron | Radio links and telemetry | Unmanned Aerial Vehicles | Protonex fuel cell | Ancillary systems | AUVSI 2017 Show report

74 zoom lens assembly had to be optimised in terms of size, weight and geometry, and all the components had to be tightly integrated with special attention to heat dissipation.” The detector is made from indium arsenide antimonide and, operating at -123 C, is classed as a ‘high operating temperature’ (HOT) infrared detector. “HOT detectors live longer and consume power more efficiently when accounting for size and weight,” Popiks said. Each sensor in the Epsilon 175 uses a specially designed ‘window’ for its respective waveband. The EO camera, laser illuminator and laser rangefinder use optical glass with anti-reflective coatings optimised for wavelengths of 400-700 nm, 830 nm and 1500 nm respectively, while the MWIR sensor uses a silicon window and diamond-like carbon outer coating to resist scratches. Hirth showcased an off-the-shelf version of its 50 bhp UAV two-stroke, the F23 NG. Dietrich Kehe told us that this air- cooled model uses twin cylinders and a displacement of 521 cc to obtain its power rating for a weight of 22 kg (less exhaust) or 33.6 kg including optional mounts, belt reduction drive and 3 kW generator. An evolution of a proven sports aviation engine, it has a boxer configuration and features CDI ignition and port fuel injection. Trig Avionics, a British company specialising in certified avionics, was showing its TT26 multi-mission system designed for Male-to-Hale UAVs engaging in critical BVLOS operations in mixed airspace. The TT26 consists of a mode-S transponder, ADS-B out broadcaster, altitude encoder and GPS – all certified up to 70,000 ft according to FAA performance criteria. Jon Roper told us, “It lets a UAS operator retrofit and upgrade for navigation indicators and surveillance compliance. It weighs just over 1 lb, and uses industry-standard RS-232 and RS-485 to connect to autopilots and complement other onboard sensors.” The unit saves weight by omitting cooling fans, owing to design choices such as paint treatment to the exterior to help dissipate heat, and heat treatments on the interior of the case to improve the radiation of heat. The three fixing points that form part of the case can be bolted directly to structural components of the UAS to provide an additional heat sink. “This enables installation next to other avionics without fear of heat damage,” Roper added. “It also comes with a certified tray to secure the box where fixtures are needed, and three 5 mm mounting points in the chassis.” Swift Engineering showcased its Swift020 small VTOL UAV. A fixed-wing ‘tailsitter’, it takes off with its nose facing vertically and transitions by pitching downwards until flying horizontally. Much of its capability is derived from its autopilot, which is configured to enable VTOL as well as vertical-to-horizontal transition. “The transition is difficult, as is turning off motors in flight, not to mention take-off and landing from a ship,” Andrew Streett told us. “Developing that in-house was a key part of the X-Blade Technology, which is our patented system for fixed-wing VTOL transition without using any rotating June/July 2017 | Unmanned Systems Technology Trig Avionics’ TT26 multi-mission system for Male-to-Hale BVLOS UAVs Sample output from Overwatch Imaging’s TK-5 Firewatch wide-area camera