SGBA: Semantic Gaussian Mixture Model-Based LiDAR Bundle Adjustment

TL;DR

SGBA introduces a semantic Gaussian mixture model for LiDAR bundle adjustment that encodes geometric and semantic info without predefined features, improving robustness and generalizability in pose estimation.

Contribution

It proposes a novel semantic GMM-based LiDAR BA scheme with adaptive semantic selection and probabilistic feature association, enhancing robustness and applicability across environments.

Findings

Achieves accurate pose refinement in challenging scenarios

Demonstrates robustness with limited geometric features

Outperforms traditional feature-based methods

Abstract

LiDAR bundle adjustment (BA) is an effective approach to reduce the drifts in pose estimation from the front-end. Existing works on LiDAR BA usually rely on predefined geometric features for landmark representation. This reliance restricts generalizability, as the system will inevitably deteriorate in environments where these specific features are absent. To address this issue, we propose SGBA, a LiDAR BA scheme that models the environment as a semantic Gaussian mixture model (GMM) without predefined feature types. This approach encodes both geometric and semantic information, offering a comprehensive and general representation adaptable to various environments. Additionally, to limit computational complexity while ensuring generalizability, we propose an adaptive semantic selection framework that selects the most informative semantic clusters for optimization by evaluating the condition number of the cost function. Lastly, we introduce a probabilistic feature association scheme that considers the entire probability density of assignments, which can manage uncertainties in measurement and initial pose estimation. We have conducted various experiments and the results demonstrate that SGBA can achieve accurate and robust pose refinement even in challenging scenarios with low-quality initial pose estimation and limited geometric features. We plan to open-source the work for the benefit of the community https://github.com/Ji1Xinyu/SGBA.