Fast Estimation of Relative Transformation Based on Fusion of Odometry and UWB Ranging Data
Yuan Fu, Zheng Zhang, Guangyang Zeng, Chun Liu, Junfeng Wu, Xiaoqiang Ren
TL;DR
The paper addresses real-time estimation of the 4-DOF relative transformation between two robots using odometry and UWB ranging data. It introduces a two-step maximum likelihood method: an unconstrained least squares initialization with projection, followed by a single Gauss-Newton refinement, achieving fast and accurate relative pose estimates under space constraints. It also provides path design and UWB configuration guidelines to guarantee identifiability and minimum operating time, demonstrated via simulations against SDP that show substantial reductions in computation time with maintained accuracy. The work enables practical real-time relative transformation estimation in constrained spaces and lays groundwork for extending to multi-robot scenarios and broader attitude estimation tasks.
Abstract
In this paper, we investigate the problem of estimating the 4-DOF (three-dimensional position and orientation) robot-robot relative frame transformation using odometers and distance measurements between robots. Firstly, we apply a two-step estimation method based on maximum likelihood estimation. Specifically, a good initial value is obtained through unconstrained least squares and projection, followed by a more accurate estimate achieved through one-step Gauss-Newton iteration. Additionally, the optimal installation positions of Ultra-Wideband (UWB) are provided, and the minimum operating time under different quantities of UWB devices is determined. Simulation demonstrates that the two-step approach offers faster computation with guaranteed accuracy while effectively addressing the relative transformation estimation problem within limited space constraints. Furthermore, this method can be applied to real-time relative transformation estimation when a specific number of UWB devices are installed.
