High-Accuracy 3D SAW RFID Tag Localization Using a Multi-Antenna Mobile Robot Based Synthetic Aperture Approach

Asset localization for inventory and management applications can benefit from the characteristics of surface acoustic wave (SAW) radio frequency identification (RFID), adding valuable information in Industrial Internet of Things (IIoT) ecosystems. An innovative approach using this technology combined with a multi-channel interrogation hardware integrated on a mobile robot platform under indoor conditions is studied in this work. With this novel system advance, SAW RFID tags can be localized in three dimensions within centimeter accuracy. The system concept and algorithms are described in detail in this paper. Furthermore, the performance in terms of localization accuracy is evaluated theoretically and experimentally and a root mean square error of 1.6 cm is achieved.