Gas Source Localization in Unknown Indoor Environments Using Dual-Mode Information-Theoretic Search

This letter proposes a dual-mode planner for localizing gas sources using a mobile sensor in unknown indoor spaces. The complexity of indoor environments creates constraints on search paths, leading to situations where no valid paths can be generated, which are termed as dead end in this letter. The proposed dual-mode planner is designed to effectively address the dead end problem while maintaining efficient search paths. In addition, the absence of analytical dispersion models that can be used in unknown indoor environments presents another critical issue for indoor gas source localization (GSL). To address this, we present an indoor Gaussian dispersion model (IGDM) that can analytically model indoor gas dispersion without a complete map. Finally, we establish a GSL framework for indoor environments along with real-time mapping, utilizing the dual-mode planner and IGDM. This framework is validated in indoor scenarios with the realistic gas dispersion simulator. The simulation results show the high success rate of the proposed method, its ability to reduce search time, and its computational efficiency. Furthermore, through real-world experiments, we demonstrate the potential of the proposed approach as a practical solution, evidenced by its satisfactory performance.