Using multi-robot active olfaction method to locate time-varying contaminant source in indoor environment

•The multi-robot active olfaction method integrates PSO with time-varying contaminant source localization.•The time-varying characteristic of contaminant source is fully considered.•The method can locate time-varying contaminant source through several robots in short time.•The applicability and reliability of the method were tested through a case study in different indoor environments.

Prevention of indoor contaminant source leak disasters is becoming an urgent issue in the indoor environment and public safety fields. Quickly locating such a source is a prerequisite for effective implementation of source control, and a key basis for further guidance on evacuation and emergency rescue. Indoor contaminant sources have many forms because of source characteristic variation. The current research focuses on continuous release from a source with constant intensity and instantaneous release from a source with impulse intensity. There are few studies of sources with varying release intensity. The main goal of the present research study was to develop a source localization method for a time-varying source. A computational fluid dynamics model of leakage for an indoor time-varying contaminant source is established, together with a search strategy using multi-robot active olfaction. Based on the time-varying leakage source localization method, the robots are used to verify method effectiveness through indoor two-dimensional ventilation room simulation experiments. The influence of factors such as intensity change, position and obstacles on the localization is analyzed, which provides a foundation for further study of contaminant source identification in an unsteady flow field.