Plume tracking strategy in turbulent environment using odor sensor with time constant

Abstract

The problem of tracking a dynamic odor plume using a realistic odor sensor model was investigated in a computer simulation. A chemical sensor typically has a significant time response delay that can disturb its practical application. This characteristic presents a challenge in tracking a dynamic plume toward the source. A reliable plume tracking strategy in a dynamic turbulent environment was designed through this simulation, which exploits the transient response of the chemical sensor. In this simulation, a mathematical model derived from a semiconductor gas sensor for sensing ethanol gas was used to model the sensor response. The sensor model was embedded into a chemotaxis-anemotaxis-based plume tracking strategy using a single sensor node to localize the source. In essence, the localization strategy is to search for the plume centerline and then move upwind along the centerline. The plume edges are estimated by evaluating the gradient of the fitting model of the frame size of the latest data points of sensor response during tracking. The strategy was tested on a turbulent environment simulated using a computational fluid dynamics (CFD) software. Although the odor distribution was complicated owing to the turbulent airflow and the obstacles, evaluation of the plume tracking strategy to localize the source starting from 404 initial positions achieved a success rate of approximately 70%.