A Sensory Instrumented Particle for Environmental Monitoring Applications: Development and Calibration

Abstract

A plethora of environmental sensing applications, including geomorphic, ecohydraulic and turbulent flow processes, involve the monitoring of the stability of bed surface particles. This work presents a miniaturized sensory instrumented particle that aims to provide a direct, non-intrusive and low-cost method for environmental monitoring of the processes taking place at the interface between the water and sediment surface. Specifically a miniaturized particle (3cm) is designed and developed to simulate the behavior of coarse bed surface particles in aquatic environments, such as rivers and estuaries. This particle has the capability of precisely and at a high frequency (1000Hz) quantifying its inertial dynamics during motion, using embedded microelectromechanical (MEMS) sensors, consisting of a triaxial accelerometer (up to 16g), a triaxial gyroscope (up to 2000°/s) and a magnetometer. The sensors are calibrated using simple physical motions to estimate the uncertainties in the inertial sensor’s logged readings. The performance of the instrumented particle and data uncertainties after using inertial sensor fusion, are assessed with two physical experiments: a random rotating motion and a controlled motor transverse table. The results of the sensor fusion of the logged readings (corrected acceleration, corrected angular velocity and orientation) are deemed reliable with an infinitesimal error range. The instrumented particle is tested at a laboratory setting under well-controlled flow conditions. The results demonstrate that the instrumented particle can be used to sense particle’s motion, which is useful for a range of environmental monitoring applications.