Ultra-Wideband Localization: Advancements in Device and System Calibration for Enhanced Accuracy and Flexibility

Abstract

We show how the state of use of Ultra-Wide-Band (UWB) system is improved by removing systematic errors (bias) on device-level to improve accuracy and apply simple procedure to automate calibration process on the system-level to reduce manual efforts. On device-level, we discern the different sources of bias and establish a method that determines their values, for specific hardware and for individual devices. Our comprehensive approach includes simple, easy-to-implement methodologies for compensating these biases, resulting in a significant improvement in ranging accuracy. The mean ranging error has been reduced from 0.15m to 0.007m, and the 3-sigma error margin has decreased from 0.277m to approximately 0.103m. To demonstrate this, a dedicated test setup was built. On system-level, we developed a method that avoids measuring all anchor positions one by one by exploiting increased redundancy from anchor-to-anchor and anchorto-tag ranges, and automatically calculating the anchors topology (relative positions between each other). Nonlinear least squares (NLS) provides the maximum likelihood estimate (MLE) of the anchor positions and their uncertainty. This approach not only refines the accuracy of tag localization but also offers a predictive measure of its uncertainty, giving users a clearer understanding of the system's capabilities in real-world scenarios. This system-level enhancement is further complemented by the integration of a ranging protocol called Automatic UWB Ranging Anyto-any (AURA), which offers additional layers of flexibility, reliability and ease of deployment to the UWB localization process.

Future Research and Trends in Ultra-Wideband Indoor Tag Localization

“…Tieman also uses the MAC protocol to monitor the energy used and compare energy consumption between each of the ranging techniques used [57]. ToF/TDoA and TWR Ranging Improvement [41], [42], [43], [44], [45], [174] Flueratoru evaluates energy consumption, distance measurement, and accuracy in 2 types of UWB physical interfaces (PHY), namely LRP and HRP (High/low pulse repetition). Measurements were made in LOS and NLOS conditions.…”