Unmanned Systems Technology 028 | ecoSUB Robotics AUVs I ECUs focus I Space vehicles insight I AMZ Driverless gotthard I InterDrone 2019 report I ATI WAM 167-BB I Video systems focus I Aerdron HL4 Herculift

Engine control units | Focus (or fuel injection) can be adjusted before the engine begins to slow down, to match the change in torque and keep the propeller and crank at the right speed. Such design care will keep the engine running and reduce the burden on the flight controller. Striking a balance between the need to widen the throttle to provide more electrical power to the airframe, for example, and the need to slow the engine during survey or descent can be challenging, and result in significant lags in control feedback. ECU design and programming then becomes more complex for parallel hybrid or full-hybrid systems generating upwards of 10 kW of electricity. For example, if a UAV in flight needs to go from cruise to climbing mode (changing the load by orders of kilowatts), or quickly evacuate unsafe airspace, the flight controller might respond by going to wide-open throttle. And although the current draw will probably have shot up, the engine might not be able to turn fast enough to provide the jump in power. At that point, the ECU may need to interact not only with the engine and motor controller but with the battery, to have the generator temporarily run off battery power. That would allow the engine to spool up to the required speeds for the power required, or perhaps for it and the generator to deliver their maximum power outputs to the propeller at the same time. Increasing the number of I/Os on the ECU might be necessary to account for the extra sensors, transistors and commands in high-power hybrid powertrains. However, it largely falls to UAV manufacturers to decide whether they want to place the intelligence for handling complex power systems on the ECU or the flight controller. One of the most notable additions being seen across ECUs designed and built for UAVs are systems for electronic logging and tracking maintenance. The growing adoption of fuel-powered UAVs has driven more customer requests for easier ways to track and reduce their operating costs. Adding an SD card to an ECU means it can precisely record fuel consumption, with a 16 Gbyte card capable of taking 50 kbit/s and holding 15 days’ worth of ECU logs. Maintenance To help with maintenance tracking, the ECU can have the SD card automatically record when maintenance has been performed. It can also track engine wear and anomalies such as overheating or knocking, and send alerts to the GCS or ground technicians if maintenance is required. Even if those recordings are not automatic, having an engine ‘log book’ functionality on the ECU would still encourage more UAV technicians to