🤖 AI Summary
This work addresses the challenge of drift-prone visual-inertial odometry (VIO) in GPS-denied environments for multi-robot systems, where existing ultra-wideband (UWB)-assisted approaches are typically limited to single robots and rely on pre-calibrated anchor nodes, compromising robustness. To overcome these limitations, we propose a distributed collaborative visual-inertial-ranging odometry framework (DC-VIRO), which, for the first time, tightly integrates VIO with online self-calibration of UWB anchors in multi-robot settings. By incorporating anchor positions into the system state and leveraging shared UWB measurements to impose geometric constraints, DC-VIRO employs right-invariant error modeling on Lie groups and distributed optimization to ensure observability and estimation consistency. Experimental results demonstrate that DC-VIRO significantly improves localization accuracy and robustness while successfully achieving distributed self-calibration of UWB anchors.
📝 Abstract
Reliable localization is a fundamental requirement for multi-robot systems operating in GPS-denied environments. Visual-inertial odometry (VIO) provides lightweight and accurate motion estimation but suffers from cumulative drift in the absence of global references. Ultra-wideband (UWB) ranging offers complementary global observations, yet most existing UWB-aided VIO methods are designed for single-robot scenarios and rely on pre-calibrated anchors, which limits their robustness in practice. This paper proposes a distributed collaborative visual-inertial-ranging odometry (DC-VIRO) framework that tightly fuses VIO and UWB measurements across multiple robots. Anchor positions are explicitly included in the system state to address calibration uncertainty, while shared anchor observations are exploited through inter-robot communication to provide additional geometric constraints. By leveraging a right-invariant error formulation on Lie groups, the proposed approach preserves the observability properties of standard VIO, ensuring estimator consistency. Simulation results with multiple robots demonstrate that DC-VIRO significantly improves localization accuracy and robustness, while simultaneously enabling anchor self-calibration in distributed settings.