A bionic plume tracing method with a mobile robot in outdoor time-varying airflow environment

A bionic plume tracing method named the Surge-S algorithm is proposed for robot odor source localization problems in outdoor time-varying airflow environment. The rapid change of wind direction in the outdoor environment leads to a fact that the odor plume released from the odor source are changing quickly, winding and intermittent. In this case, the robot would easily lose the contact with the odor plume, resulting an inefficient plume tracing. In order to track the plume efficiently in outdoor time-varying airflow environments, inspired by the plume-tracing behavior of the male moth, the Surge-S algorithm is proposed. The proposed method makes the robot surge a given distance against the wind after the contact with the plume. When the robot loses the contact with the plume, it will search the plume like the casting of the moth, following a gradually increasing S-shaped path based on the end location of the surge and with a center line in upwind direction. The gradually increasing S-shaped path is designed to make the robot likely re-meet the plume within the area possibly covered by the plume, and thus the robot can get into next plume tracing and gradually approaches the odor source. Simulation experiments were carried out and the proposed method was compared with the classic Spiral-surge algorithm. The simulation results show the feasibility and validity of the Surge-S method.