Design and implementation of an innovative airborne electric propulsion measure system of fixed-wing UAV

The electric propulsion system combination of unmanned aerial vehicles (UAVs) plays a vital role in improving the endurance time for newly designed aircraft. To realize the measurement of the parameters of the electric propulsion system in an actual flight, a novel airborne powered test scheme is proposed and developed in this work. Both the flight test and wind tunnel experimental study are performed to estimate the accuracy of the test approach by discussing the effect of the airspeed on the electric aircraft powered system. Additionally, the thrust, torque, and efficiency curves are also studied as the increase of revolutions per minute (RPM) in flight tests. The results suggest that the innovatively designed electric-powered test system is capable of measuring the aircraft propulsion efficiency parameters within 4% when compared to a wind tunnel experiment. Compared with the wind tunnel experiment, the uncertainty of the airborne test is 0.32% (motor speed), 0.83% (voltage), 1.17% (current), 0.93% (thrust), and 2.0% (torque). This kind of airborne test method can replace the high cost of wind tunnel test, which is more suitable for fixed-wing aircraft, has high application potential for the propulsion system optimization, and real-time state monitoring of power equipment.