A pedestrian POS for indoor Mobile Mapping System based on foot-mounted visual–inertial sensors

Abstract

The mobile mapping system (MMS) is an enabling technology for indoor location-based services. The position and orientation system (POS) is one of the cores of the mobile mapping system. This paper proposes a pedestrian POS solution for infrastructure-free environments based on the fusion of foot-mounted IMU and stereo camera. The structure from motion (SFM) constructs the trajectory and environment under the condition with rich visual textures; the stereo camera detects loop-closure for mitigating the accumulated error; the foot-mounted pedestrian dead reckoning (Foot-PDR) provides reliable continuous trajectories using the IMU when the visual-based system degrades or crashes. The feasibility and reliability of the proposed system were verified by an office building test and an underground parking lot test. The proposed system achieved 0.237 m and 0.227 m position errors in these two scenarios, respectively. Moreover, the system can maintain the average position accuracy of 0.3 m when the camera shortly failed in some areas.