Mobile robot based odor source localization via particle filter

We consider odor-source localization using a mobile robot in a time-variant airflow-field environment. Novel plume tracing and odor-source declaration methods are presented. When odor plume clue is found, an odor-patch path is estimated by a dynamic-window approach, and the robot traces the plume along a route planned from the odor-patch path. In parallel, a particle filter is used to localize an odor source. The source is declared if the estimated locations converge in a relatively small area for a given period. In view of the common foundational odor concentration that already exists in the local or even whole searched area before the robot searches, differential concentration based on moving-average value is used to obtain an adaptively variable concentration threshold. Experiment results in an indoor time-variant airflow experiment show that the robot can effectively approach and declare the odor source.