Implementation Evaluation of Dynamic Token DS-TWR in SmartFinder with IR-UWB

In construction sites, it is important to determine the locations of workers for work and safety management. However, it is difficult to install permanent localization equipment at construction sites and their layouts frequently change. Therefore, localization for construction sites must be deployed agilely without requiring permanent installation and have a localization error of under 50 cm. SmartFinder has been proposed as an indoor localization method which can estimate the locations of many devices in a large space with only three anchor nodes, making it possible to agilely localize devices with low dependency on infrastructure. To apply SmartFinder with Impulse Radio Ultra-Wide Band (IR-UWB) to construction sites , we previously proposed Dynamic Token Double-Sided Two-Way Ranging (DS-TWR), which is distributed inter-device ranging that does not require a centralized control function for IR-UWB ranging. However, Dynamic Token DS-TWR may not work effectively when obstacles are present in the space. In this paper, we propose an advanced Dynamic DS-TWR, which enables multiple access control of ranging communication in a space with obstacles. Then we demonstrate its ranging accuracy in a space with obstacles and the localization accuracy of SmartFinder with the proposed ranging.