Continuous-Time Ultra-Wideband-Inertial Fusion

TL;DR

This paper presents SFUISE, a real-time continuous-time ultra-wideband-inertial fusion system using quaternion spline parameterization, offering superior online motion estimation performance over existing discrete-time methods.

Contribution

It introduces a novel continuous-time sensor fusion framework with quaternion cubic B-splines, enabling asynchronous multi-sensor fusion and online calibration.

Findings

Real-time performance demonstrated in real-world scenarios

Superior accuracy over state-of-the-art discrete schemes

Open-source implementation provided

Abstract

We introduce a novel framework of continuous-time ultra-wideband-inertial sensor fusion for online motion estimation. Quaternion-based cubic cumulative B-splines are exploited for parameterizing motion states continuously over time. Systematic derivations of analytic kinematic interpolations and spatial differentiations are further provided. Based thereon, a new sliding-window spline fitting scheme is established for asynchronous multi-sensor fusion and online calibration. We conduct a dedicated validation of the quaternion spline fitting method, and evaluate the proposed system, SFUISE (spline fusion-based ultra-wideband-inertial state estimation), in real-world scenarios using public data set and experiments. The proposed sensor fusion system is real-time capable and delivers superior performance over state-of-the-art discrete-time schemes. We release the source code and own experimental data at https://github.com/KIT-ISAS/SFUISE.