Opportunistic radio SLAM for indoor navigation using smartphone sensors

This paper provides the experimental results of a system utilising only the sensors available on a smartphone to provide an indoor positioning system that does not require any prior knowledge of floor plans, transmitter locations, radio signal strength databases, etc. The system utilises a Distributed Particle Filter Simultaneous Localisation and Mapping (DPSLAM) method to provide constraints on the drift of a simple hip-mounted Inertial Measurement Unit (IMU) integrated into the smartphone and providing the core information on the movement of the user. This system was developed during a project investigating methods of providing relative positioning systems to a team operating for extended periods without GPS. The paper concentrates on the DPSLAM positioning technique suitable for use by an individual with no prior knowledge of the area of operation before deployment. As with all SLAM systems, the user is simply required to revisit locations periodically to enable IMU drifts to be observed and corrected.