Miniature Multihole Airflow Sensor for Lightweight Aircraft Over Wide Speed and Angular Range
Lukas Stuber, Simon Luis Jeger, Raphael Zufferey, Dario Floreano
AI summary
Problem
Current airflow sensors are either too heavy or require high airspeeds, making them unsuitable for lightweight UAVs that operate at low speeds and are highly susceptible to dangerous stalls.
Approach
The authors designed a lightweight, tubing-free multihole pressure probe with integrated differential sensors, optimized its geometry via wind tunnel testing, and calibrated it using multivariate polynomial regression.
Key results
- Conical tips significantly improve measurement resolution and reduce noise compared to spherical tips
- Achieves 0.44 m/s airspeed and 0.16° angular accuracy across 3-27 m/s and ±35° ranges
- Successfully validated in outdoor acrobatic and stall-prone flight tests
- Design and CAD files released to the public domain
Why it matters
This lightweight, low-speed sensor enables safe stall detection and expanded flight envelopes for small, uncrewed aerial vehicles.
Abstract
An aircraft’s airspeed, angle of attack, and angle of side slip are crucial to its safety, especially when flying close to the stall regime. Various solutions exist, including pitot tubes, angular vanes, and multihole pressure probes. However, current sensors are either too heavy (> 30g) or require large airspeeds (>20 m/s), mak- ing them unsuitable for small uncrewed aerial vehicles. We propose a novel multihole pressure probe, integrating sensing electronics in a single-component structure, resulting in a mechanically robust and lightweight sensor (9 g), which we released to the public do- main. Since there is no consensus on two critical design parameters, tip shape (conical vs spherical) and hole spacing (distance between holes), we provide a study on measurement accuracy and noise generation using wind tunnel experiments. The sensor is calibrated using a multivariate polynomial regression model over an airspeed range of 3-27 m/s and an angle of attack/sideslip range of ±35◦, achieving a mean absolute error of 0.44 m/s and 0.16◦. Finally, we validated the sensor in outdoor flights near the stall regime. Our probe enabled accurate estimations of airspeed, angle of attack and sideslip during different acrobatic manoeuvres. Due to its size and weight, this sensor will enable safe flight for lightweight, uncrewed aerial vehicles flying at low speeds close to the stall regime.