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95 accounting for the differences between a copter-type VTOL system and one with the weight, balance and aerodynamic idiosyncrasies of an added tail and wings, as well as updating the user interfaces and the hardware-in-the-loop simulator. “When you introduce wings and a rudder to a multi-rotor platform, you interfere with what the multi-rotor wants to do in take-off and landing, so there are significant design implications to be considered when moving to VTOL- transition aircraft,” Loewen added. Elistair debuted its Orion tethered UAS, which is aimed at providing a persistent platform for surveillance and comms relays. “It’s designed for at least 10 hours of flying time, deployable up to 80 m or 200 ft in the air, and with police, defence, and industrial services in mind,” said Steve Allcock. “Since power is delivered through the tether it allows us to have a small safety battery for emergencies, and we can then provide a truly persistent capability by optimising performance and endurance.” The system currently supports a standard EO camera and an XDM EO/IR camera with 30x optical EO zoom and 4x IR zoom. A 200 Mbit/s comms link is also delivered over the patented tether design. The system has a standard operating weight of 10 kg, and is designed with dual-redundant autopilot sensors, motors and power distribution, as well as an emergency parachute for added safety. “In the future, the aspiration will be to integrate ‘follow me’ functionality so that the Orion can be tethered and operated from a moving vehicle,” Allcock added. “That will be the challenge for our technical team to solve, as there are several different ways of achieving it.” Drone Rescue Systems showcased its parachute safety system for UAVs. The system is designed as an autonomous solution with its own sensors, electronics and embedded software to detect any potential problems with a UAV. A fusion of sensor data combined with machine learning is used to program, record and identify scenarios and manoeuvres that should trigger parachute release. Andreas Ploier commented, “A UAV might suffer from a failure of the flight controller, the power supply or any other issue while flying beyond the visual line of sight, so the independence of the system is critical to ensure the parachute can be ejected without operator input.” To save weight, the system uses a rubber catapult rather than springs or explosive elements to eject the parachute. Its overall weight is 280 g for the version meant for UAVs weighing 3-7 kg, and 350 g for those weighing 15-20 kg. BMPower debuted its hydrogen fuel cell power system for small UASs. The overall powertrain comes in power variants rated at 500, 1000, 2000 and 3000 W. In its smallest size, the system consists of a 1.15 kg fuel cell module, a 2.3 kg (7 litre) hydrogen gas cylinder, a 300 g fuel processing system and a 400 g control module (including wires) for a total weight of 4.15 kg. “It can operate normally down to -40 C – a far lower temperature than with other fuel cell systems,” said Alexey Ivanenko. “Also, the proprietary pressure regulator allows quick replacement of hydrogen cylinders without any special equipment.” The power system comes with a voltage stabiliser as well, to fix the voltage output at whatever level is required. Depending on the variant, the system can support hydrogen cylinder volumes of 7, 10 or 25 litres, and run for between 110 and 440 minutes, with energy densities of between 383 and 672 Wh/kg. CUAV Expo Europe 2018 | Show report Unmanned Systems Technology | June/July 2018 Elistair’s Orion is aimed at police, defence and industrial roles The BMPower hydrogen fuel cell comes in variants ranging from 500 to 3000 W