An Ultrasonic airspeed sensor prototype for a fixed-wing drone

Abstract

This project explores the development of a low-cost ultrasonic airspeed sensor prototype that can be implemented in fixed-wing drones. The current methods for measuring airspeed, such as the Pitot tubes, have limitations in terms of their usability in low-cost Unmanned Aerial Vehicles (UAV). By exploiting the Doppler shift in ultrasonic sensing, the proposed prototype offers a viable alternative to traditional methods of calculating airspeed. The prototype comprises an ultrasonic transmitter and two receivers aligned at angles between 30± and 60±, a signal processing circuitry, and a micro-controller. Through systematic experiments, an investigation of the sensor’s response to various airspeeds was carried out. The collected data was extensively analysed to evaluate the system’s performance, accuracy, and operational range. The results successfully demonstrate the feasibility of using ultrasonic technology to estimate the airspeed of a fixed-wing drone by operating the transmitter in a pulsed mode setting and the receiver in a scanning mode configuration, applying the Doppler beam swinging method, calculating the resulting frequency shift and thereby deriving the indicated airspeed.