Robust and Scalable Multi-Robot Localization Using Stereo UWB Arrays
Hanying Zhao, Lingwei Xu, Yi Li, Feiyang Wen, Haoran Gao, Changwu Liu, Jincheng Yu, Yu Wang, Yuan Shen
AI summary
Problem
Current UWB localization lacks 3-D directional measurements, suffers from rapidly declining update rates as networks scale, and is highly susceptible to hardware and propagation errors.
Approach
The authors design a lightweight stereo UWB array to measure 3-D bearing and distance, calibrate intrinsic sensor errors, and implement a signal-multiplexing network ranging protocol to fuse UWB and IMU data for distributed relative localization.
Key results
- Centimeter-level localization accuracy
- 100 Hz update rate using UWB only
- Robust performance in complex propagation environments
- Scalable network capacity for large multi-robot swarms
Why it matters
Provides a critical, infrastructure-free positioning foundation for safe and coordinated swarm robotics in GNSS-denied environments.
Abstract
In environments where robots operate with limited global navigation satellite system accessibility, ultra-wideband (UWB) localization technology is a popular auxiliary solution to assist visual–inertial odometry systems. However, current UWB approaches lack 3-D pairwise localization capability and suffer from rapidly declining localization update rates as the network scales, limiting their effectiveness for swarm robotic applications. This article presents a novel UWB sensor that enables 3-D pairwise localization and a localization scheme that can deliver robust, scal- able, and accurate position awareness for multi-robot systems. Our approach begins with calibrating intrinsic UWB errors from hard- ware deviations and propagation effects, yielding high-accuracy distance and direction measurements. Using these measurements, we perform distributed relative localization through inter- and intra-node cooperation by integrating UWB and inertial measure- ment unit data. To enable swarm-scale operation, our platform implements the signal-multiplexing network ranging protocol to maximize update rates and network capacity. Experimental results show that our approach achieves centimeter-level localization ac- curacy at high update rates (100 Hz with UWB only), validating its robustness, scalability, and accuracy for robotic applications.