Unmanned Systems Technology 008 | Alti Transition UAS | Ground control systems | Xponential 2016 report | Insitu Orbital N20 | UAVs | Solar power | Oceanology International 2016 report

28 example is 60.7 mm in diameter, 39.5 mm in length and weighs 255 g. The company quotes an idle current of 0.9 A, a maximum continuous current of 40 A, maximum continuous power of 1180 W and an internal resistance of 33 m Ω . The stators are hand-wound at 180 C from a single thick, oxygen-free copper wire to enhance resistance to short- circuits. The housing is machined from aluminium and the stators are made from 0.2 mm laminations of silicon steel for efficiency and minimum eddy current losses. Stator plates are epoxy coated to prevent shorts in the windings, and a stainless steel propeller adapter is available as an option. The propeller shaft is designed to prevent loosening, and the large bearing has a claimed Mean Time Between Failures of 160 hours. Integral air cooling is to a patented design, and the motor is claimed to be waterproof as well as resistant to dirt and sand. The motor is tested to military standards, says T-Motor. For power and signal distribution from the batteries to the motors, avionics and payload, the prototypes are wired up, but the company is working on a distribution board/box for production. This will have a cable connector with about 20 pins to mate it with the avionics box, which has other interfaces for sensors. PX4-based flight control De Villiers says the Alti Transition flies much like a large quadcopter in hover mode but with less yaw authority; pitch and roll are very responsive, with yaw taking a little longer owing to the long wingspan and lateral mass. The conventional differential motor speed technique is used for yaw control in the hover. To control the aircraft, Alti has developed its own autopilot based on the open source PX4 standard with a companion PC. The PX4 flight stack is described as a complete control solution for multicopter and fixed- wing UAVs, and even ground robots, while the middleware consists of a robotics communications toolkit that the development team calls efficient, lightweight and “blazing fast”. Developed from 2009 by the Computer Vision and Geometry Laboratory at ETH Zurich, otherwise known as the Swiss Federal Institute of Technology, PX4 software is also supported by the institute’s Autonomous Systems Laboratory and Automatic Control Laboratory. It received a further boost when Qualcomm Technologies adopted it for its new Snapdragon Flight board, which forms the core of the Snapdragon June/July 2016 | Unmanned Systems Technology For transport, Transition can be disassembled into four sections – the two outer wings, fuselage/wing roots and the tail hoop with booms and stabiliser CAD rendering showing the engine fairing with only the cylinder exposed; detail of rear lift motor that will be integrated into the wing centre/fuselage for production