Handheld Localization Device for Indoor Environments

In this paper, we address the problem of human safety during the search of underground or unknown indoor environments in scenarios where it is required to share the information about the position of the personnel such as first responders or speleologists. We report on the developed localization device to estimate and transmit the user position and state through a custom communication system. The information provided by the device serves to monitor the user state, enable communication between the user and the base station located outside the environment being searched. The personnel's position in the environment is thus provided to the mission supervisor in the case of an emergency. The device is based on low-cost off-the-shelf cameras for vision-based localization and low-bandwidth communication modules suitable for long-range communication in underground environments. Furthermore, the communication range is extendable by affordable transceivers that allow the dynamical building of independent communication networks in the operational environment. The performance of the communication system has been examined in an experimental scenario where five transceivers sufficiently cover 280 m of cave tunnels. The system can localize a human independently on any infrastructure supported by a report on the experimental deployment in an urban scenario with both indoor and outdoor areas.