UST030

70 Show report | Commercial UAV Expo 2019 capabilities tested to Mil-Std 810G and DO-160G as well as I/Os including three USB 3.1s, two HDMIs, two CAN 2.0bs, and others,” Callaghan added. CR Flight attended the show to unveil the three production-ready models of its counter-rotating electric motor technology, which is designed to produce thrust that is equivalent to or greater than motors of similar size and voltage at far less current draw and therefore power. “On a standard motor, you’re just turning one side of it – the rotor – where the permanent magnets are mounted,” said Jonathan Emigh. “Our configuration uses what we call a ‘rotary transformer’, which is integrated into the assembly and allows us to power the armature [or stator] as well as the rotor so that they’re both turning in opposite directions, with no gears and no parasitic frictional losses. “With counter-rotating props the standard ‘swirling’ thrust pattern is now redirected straight down, gaining 10- 15% more thrust for free. The rotational torque applied by a standard motor is eliminated, reducing stress and vibration on the drone. “Combined with additional cooling of the motor, the net gain is between 15 and 30% for the same power as a standard motor, allowing UAV operators to swap out significant battery weight and add extra payload instead.” The rotary transformer is a form of rigid slip ring that is designed to allow the stator to move using the energy generated by the reactive force from the rotor and its propeller. A second propeller can thus be mounted on the housing (to which the stator is fixed); the movement of the stator slows the first propeller to half speed and engages the second prop at half speed as well. This also reduces the load and speed of the bearings, which is the main cause of failure for the motors. A large propeller is used to harvest the thrust at a lower rpm. “What the transformer essentially does is pass power through plates that aren’t touching but are still conducting, allowing us to drive 10-15,000 rpm at 200 A on our largest models,” Emigh added. “They also handle cooling and power spikes much better than most motors, because spinning the armature turns the inside of the motor into an axial compressor, forcing air through it. Because of the amount of cooling, you can pull much more power through it if you need to.” The smallest of the three coaxial motor models is the V10, so named for the 10 lb (4.54 kg) of thrust it produces at maximum constant operation when fitted with an 18 in (45.72 cm) diameter propeller. It is aimed at commercial UAS operations such as multi-rotor survey UAVs carrying Lidar payloads. When spinning one propeller only and set to produce 6 lb of thrust, it consumes 32-33 A, but when the rotary transformer is engaged it consumes 21-22 A for the same thrust output. Both modes operate over a 30.6 V supply. Next in order of scale is the V20, a 20 lb thrust motor that ordinarily is paired with a 76.2 cm propeller. The third motor, the V50, comes with a 106.68 cm propeller and produces 50 lb of thrust. The company is currently testing the rotary transformer to determine an exact lifespan figure, which is already more than 1200 hours. Swarmly is a developer of turnkey solutions for low-density UAV autonomous swarm operations, and it displayed a number of its RF boards and demonstrator UAVs it uses to test and develop its swarming technology. “We aim to build specific mission- centric swarm solutions. For example, when clearing land mines you might have 60 square miles to cover, which is expensive, unsafe and slow to do manually,” explained Igor Rafalovsky. “We would deploy a multi-tiered solution. First, we would use 50 light fixed-wing UAVs such as our H1 Athena to detect the IR signatures of mines, and build a map of potential mine sites. “Then, five of our X2 Xelos quadcopters can fly out with a more extensive array of sensors to inspect and confirm the real mine sites from among these, and finally a series of disposable UAVs fitted with explosives can be sent out to detonate the mines.” The Cyprus-based company also sees search & rescue and wide-area facility security as key areas where its swarm technology can save time and lives. Its craft use vision-based SLAM for February/March 2020 | Unmanned Systems Technology CR Flight’s V10 counter-rotating electric motor