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

51 advanced automotive engine platforms both in production and race automobiles. Currawong brings aerospace-grade fuel injection technology proven through more than 50,000 man-hours in various UAV applications and, among other assets, Power4Flight brings a deep understanding of the relationship between a UAV autopilot and its engine control system. Cobra’s president Sean Hilbert says, “Our group has a huge advantage in being able to integrate flight control and engine control. Because we have an insight into the control of the entire aircraft – whether it is an engine load, an auxiliary load or a manoeuvre the plane is going to go through – we have the ability to feed that forward into the engine controller in a highly integrated way.” The geographical split between the three parties has been addressed by all of them installing an identical Tygerdyne dynamometer. This has an eddy current absorber with motoring capability plus full high-speed instrumentation, and is housed in an environmental chamber to control temperature and humidity. Hilbert points out that it is specifically set up for low-power engines, and provides data “at a level not matched by many others in the marketplace”. This dyno offers the likes of measurement of friction and pumping losses, and even in-cylinder combustion analysis. “We have a capability for engine testing that other vendors don’t have,” says Hilbert. “Few others have a motoring dynamometer that is instrumented to allow you to map the engine properly, look at all the data and know exactly where you are operating throughout the whole envelope. Without that you resort to making ‘guesstimates’ and you can’t see subtle differences between engines and engine settings.” For its part, Cobra has a full production CNC ’shop in-house, plus additive manufacturing equipment and a quality control laboratory that embraces advanced metrology and test equipment. Currently Cobra has a global supply chain of 150 companies underpinning its hand assembly of 2000 customer motocross engines each year. The plan is to supply core engines that have been built at Cobra to Power4Flight, where they will be fitted with Currawong fuel and control hardware, and prepared for integration with the customer’s UAV project, including suitable mapping. Design of the A33 The A33 is a 33.4 cc single-cylinder two-stroke. It has a direct drive for the propeller on the nose of its crankshaft and the admission of the charge into its crankcase at the other end, axially. This is possible since the crankpin is cantilevered with both main bearings positioned ahead of the crank throw. The cylinder is upright and air-cooled. The engine has port fuel injection and twin spark ignition. It is to be offered in two versions – the A33i will offer active exhaust technology, while the A33n will not, in the interest of minimising cost. Both versions have been developed initially around the use of gasoline. Hilbert explains, “The use of heavy fuel calls for a lot of care and maintenance, in particular with lots of chasing for deposits. Commercial users aren’t interested in heavy fuel, and for now it is in commercial uses where we see our market.” Cobra Aero A33i | Dossier Unmanned Systems Technology | February/March 2017 Our insight into the control of the entire aircraft gives us the ability to feed that into the engine controller in an integrated way A33n (this version lacks the active exhaust technology)