Full-Bridge Design for Error Reduction of 3-D Printed Mechanical Wind Sensor

In this article, a 3-D printed mechanical wind sensor with reduced measurement errors is demonstrated. This sensor consists of a cylindrical sensing structure arranged vertically in the center of a cross-shape cantilever. Eight strain gauges are symmetrically designed on the four beams of the cross cantilever to measure the airflow-induced cantilever deformation. With these eight strain gauges, two sets of Wheatstone full-bridge circuits can be constructed, enabling the measurement errors of the mechanical wind sensor to reduce remarkably. The experimental results indicate that, compared with the four-strain-gauge mechanical wind sensor in the previous work, the eight-strain-gauge design presented in this article can achieve a 62.4% sensitivity improvement for wind speed measurement. This increased sensitivity allows the wind sensor to realize a maximum speed measurement error of 0.53 m/s in the range of 0–30 m/s, achieving a 39.1% reduction compared with 0.87 m/s of the previous four-strain-gauge sensor. In addition, the test results also show that the proposed full-bridge sensor can define the airflow direction over the full range of 360° with a maximum error of 6°, which is 2° less than the four-strain-gauge device.