UWB Tracking for Home Care Systems with Off-the-Shelf Components

摘要

This study presents preliminary results of a broader research on Home Robot monitoring for elder people. The final goal of the project is the development of a robot that works in synergy with an automatic fall detection device, reaching the patient and checking his condition in case of triggered alarm. This paper covers the initial steps necessary for the design of the tracking network which provides the machine with the subject's position, in particular the single node performance. The network is based on Ultra-Wide Band (UWB) wireless transceivers that in this study are the Decawave EVB1000 evaluation boards. Two types of analysis have been performed on the anchor: a Line of Sight (LOS) baseline accuracy and interference robustness. The results demonstrate that, for LOS distance estimation, to achieve a margin of error below 15 cm, the node has to be closer than 12 m to the target. If we remove the line of sight condition, introducing a subject walking straight between the two anchors, the error is spread in the order of 10 cm from the original baseline for a 10 m nodes distance recording. If the path is obstructed instead by a subject walking perpendicularly to the nodes instead leads to a different types of perturbations, with an absolute error below 13 cm.