Augmented UWB-ZUPT-SLAM Utilizing Multisensor Fusion

This article proposes a generalized UltraWideBand (UWB)-Zero-velocity-UPdaTe (ZUPT)-simultaneous localization and mapping (SLAM) algorithm, a SLAM approach, utilizing a combination of foot-mounted localization systems integrating inertial measurement units (IMUs), UWB modules, barometers, and dynamically-deployed beacons incorporating UWB, IMUs, and reference barometers. The proposed approach leverages a ZUPT-aided Inertial Navigation System augmented with self-contained sensor fusion techniques to map unknown UWB beacons dynamically deployed in an environment during navigation and then utilizes the localized beacons to bound position error propagation. An experimental testbed was developed, and we conducted two series of experiments to validate the performance of the proposed approach. The first experiment involved high-accuracy motion capture cameras in generating ground truth, and the results showed that the proposed approach estimated positions of UWB beacons with a maximum localization error of 0.36 m, when deployed during the first 15 and 20 s of the navigation. In the second experiment, a pedestrian traveled for around 3.5 km in 1 h in a large multifloor indoor environment and deployed seven beacons, during the first 63, 151, 290, 399, 517, 585, and 786 s of the experiment. The proposed generalized UWB-ZUPT-SLAM had a 3-D mean absolute error of 0.48 m in this experiment, equivalent to 0.013% traveling distance.