Accurate position tracking with a single UWB anchor

TL;DR

This paper presents a novel approach for accurate robot localization using only a single UWB anchor and a low-cost IMU, employing an EKF to estimate pose and correct errors.

Contribution

It introduces a single-anchor UWB localization method combined with IMU data, enabling effective pose estimation and error correction for robotic tracking.

Findings

Effective correction of accumulated error in robot tracking

High accuracy in position estimation with minimal hardware

Robust performance in indoor and outdoor environments

Abstract

Accurate localization and tracking are a fundamental requirement for robotic applications. Localization systems like GPS, optical tracking, simultaneous localization and mapping (SLAM) are used for daily life activities, research, and commercial applications. Ultra-wideband (UWB) technology provides another venue to accurately locate devices both indoors and outdoors. In this paper, we study a localization solution with a single UWB anchor, instead of the traditional multi-anchor setup. Besides the challenge of a single UWB ranging source, the only other sensor we require is a low-cost 9 DoF inertial measurement unit (IMU). Under such a configuration, we propose continuous monitoring of UWB range changes to estimate the robot speed when moving on a line. Combining speed estimation with orientation estimation from the IMU sensor, the system becomes temporally observable. We use an Extended Kalman Filter (EKF) to estimate the pose of a robot. With our solution, we can effectively correct the accumulated error and maintain accurate tracking of a moving robot.