Cylindrical-Shaped Waterflow Vector Sensor Using Multiple Absolute-Pressure Sensors and Polynomial-Regression Models

With the growing interest in leveraging sensor technology for sustainable and efficient aquaculture, the measurement of ocean currents is considered a critical aspect of fish-cage environment monitoring. Conventional ocean-current sensors are typically large with high-energy consumption. Thus, they fall short of the specific demands for monitoring fish cages, which require the installation of multiple sensors in a small area. In this study, we developed a compact waterflow-vector sensor equipped with six absolute-pressure sensor elements. These elements measure the pressure on the surface of a cylinder-like housing. Through the application of fourth-degree polynomial regression, the pressure data are transformed into 2-D water-velocity and direction measurements. We fabricated a sensor based on a design informed by simulations and conducted circulating water-tunnel experiments using the fabricated sensor. Polynomial-regression models were constructed and validated from the experimental pressure output, and the models achieved an estimation accuracy of 0.21 m/s in velocity and 10° in direction within a 2.0 m/s range. Thus, our proposed sensor demonstrates the potential for monitoring sea currents in aquaculture.