Integration of CTA Sensors for Resultant Velocity Measurement in Monocopter

In this paper, we present the first integration of constant temperature anemometry (CTA) sensors into a monocopter blade for direct, real-time measurement of local resultant velocity. Two miniaturized probes—a hot-wire sensor (Wind Sensor Rev. P) and a hot-film sensor (Micro-CTA)—are calibrated in a wind tunnel and tested on a spinning rig. Experimental results show that both sensors measure velocity with less than 5% error in controlled conditions and exhibit minimal inertial interference. At low pitch angles and angular speeds, sensor readings align closely with Blade Element Momentum Theory (BEMT) predictions. However, significant deviations occur at higher angles and speeds, emphasizing the role of unsteady, three-dimensional flow. Finally, we install the sensors on a modified Single Actuator Monocopter (SAM) platform. Flight tests demonstrate the feasibility of real-time onboard resultant velocity measurement, revealing notable discrepancies from BEMT predictions. This proof-of-concept highlights CTA’s potential to improve flight performance in next-generation monocopter designs.