Unmanned Systems Technology 012 | AutoNaut USV | Connectors | Unmanned Ground Vehicles | Cobra Aero A33i | Intel Falcon 8+ UAV | Propellers | CES Show report

66 frequency protocol, somewhat similar to Bluetooth but a lot simpler and a bit more flexible,” Stumpf says. “The data rate is up to 500 kbits per link, so with two transceivers we can send up to 1 Mbit/s of control data.” This control link also makes use of frequency-hopping spread spectrum (FHSS) transmission, in which a carrier is rapidly switched between multiple frequency channels in a pseudo- randomised pattern that the UAV’s transceivers and Intel Cockpit GPS will have pre-installed. Much like the dual redundant data link, FHSS is useful in urban canyons, where buildings can reflect signals at certain moments and frequencies, causing the loss of data packets and the scrambling of messages at critical junctures. Also, in an area of highly congested comms – an increasingly likely scenario as commercial UAVs become ubiquitous – the loss of data packets becomes even more likely as multiple systems use the same wireless frequency. As Stumpf explains, “Hopping to another frequency in the same spectrum gives greater reliability and an increased likelihood that at least some of the packets will get through, even if the band is used by others.” Such a technique may thus prevent mid-air collisions or the temporary loss of a UAV owing to control signals being cut. Power and propulsion As well as the use of redundant electronics buses with multiple-pin connectors running between the motor controllers and the navigational processors, the Falcon 8+ is designed to compensate for the loss of one or more motor or propeller. Just as the Trinity flight controller’s algorithms allow it to compensate for forces from winds (of up to 16 m/s) and uneven weight, it can also detect the absence of a working motor or propeller, and switch off the corresponding motor on the opposite motor rail. Each motor rail consists of four motors mounted atop the carbon tube, with the motor controllers installed within. The motors themselves weigh about 6 g each and use carbon fibre-reinforced plastic propellers measuring 20 x 11.4 cm. The use of lithium-polymer batteries is February/March 2017 | Unmanned Systems Technology The Falcon 8+ uses FHSS in the 2.4 GHz band to minimise the chances of interference to the data link in urban and industrial zones If you connect two battery packs to two plugs, if one battery breaks down then that actually drags the other one down with it