Unmanned Systems Technology 010 | nuTonomy driverless taxi | Embedded computing | HFE International marine powertrain | Space vehicles | Performance monitoring | Commercial UAV Show Asia report

76 Report | Commercial UAV Show Asia Swiss start-up Flyability also showcased its approach to preventing collision damage to UAVs and their payloads. The company’s flagship Elios UAV is, at its core, a quadcopter powered by four brushless dc motors and three 28 Ah lithium-polymer battery cells, integrated with a lighting system, and a full HD and thermal camera payload with 180 º tilt. Around the Elios, however, Flyability has constructed a 100 g spherical cage-like frame, using 120 carbon fibre reinforced plastic rods held together with 60 pentagonal plastic bindings in a geodesic structure. “This shape provides a lot of stiffness and robustness for minimum weight,” said Flyability’s Dr Adrien Briod. “We ran a lot of simulations to optimise this cage to take considerable force from impacts without breaking. We can collide at 15 kph into a wall, and continue flying completely undisturbed, while most UAVs impacting at only a few kph would be destroyed.” Also, the decoupling system that links the cage to the UAV gives the cage three degrees of freedom from the vehicle, the mountings for which are also made from stiff carbon fibre, keeping the UAV stable should the cage rotate against a wall due to cramped flying conditions. The craft’s digital control link extends to 5 km with line of sight, although reflections of the signal off metal or other surfaces allow operations in applications such as inspecting the confined spaces in the oil & gas and maritime industries, the boiler of a power plant or crevasses in glaciers, where manned missions would be hazardous. RAN Systems from Poland is developing a radar-based sense and avoid system, Radoslaw Rak announced at the show. It has a detection range of up to 500 m for large objects such as other UAVs, with a minimum reliable detection range of 100 m for objects such as small birds. When asked why radar was chosen at a time when Lidar sensors and 3D cameras are growing in popularity for obstacle avoidance platforms, Rak said, “Radars can ‘see’ mirrors and glass much more easily than lasers, which can bounce around in a city with many glass buildings, such as Singapore. Radar also allows all-weather operation, night and day and guarantees, and effective detection distance an order of magnitude greater than other competing technologies, like Lidar and camera.” The system uses digital beam-forming radar and has a standard operating frequency of 10 GHz, although this can change minimally between versions, and it stays within the X band to avoid the need for a licence. Other advantages include very low power consumption (3 W) and low overall weight at roughly 35 g, although these specifications may change as development continues. Septentrio displayed its SWaP- optimised GNSS receiver module, the AsteRx-m UAS. Intended for micro-UASs with tight SWaP-constraints, the unit measures 47.5 x 70 mm, and consumes 400-700 mW depending on accuracy settings, which can be fixed at submetre-level or centimetre-level accuracy (0.6 cm + 0.5 ppm vertically and 1 cm + 1 ppm horizontally) if using the optional real- time kinematic (RTK) processing. The AsteRx-m weighs 27 g, and along with the greater accuracy provided by dual antennas, it supports the use of GPS and GLONASS signals through 132 hardware channels for simultaneously tracking all visible satellites in either constellation. October/November 2016 | Unmanned Systems Technology The Flyability protective cage withstands collisions of up to 15 kph Part of the RAN Systems radar- based sense and avoid system