Advanced Dynamometer Designed to Fully Characterize the Propulsion System for a UAV

One of the more difficult aspects of designing a propulsion system for an unmanned aerial vehicle (UAV) is selecting a propeller and motor combination that will not only give optimum performance at the desired flight speed, but also allows the aircraft to become airborne. To aid in this critical aspect of flight, a low-cost dynamometer system was developed that can be used to measure the thrust, torque, rotational rate, voltage, current, and airspeed of the system.

This low-cost dynamometer was designed utilizing a low-cost microprocessor so as to be a stand-alone system. The system can currently measure thrust up to 176 oz and torque over a range of ±324 oz-in. The system has been tested in a low-speed wind tunnel using an electric motor and propeller. The results revealed that the thrust and torque coefficients and overall efficiency could all be determined to within ±2.5%.