VKFPos: A Learning-Based Monocular Positioning with Variational Bayesian Extended Kalman Filter Integration
Jian-Yu Chen, Yi-Ru Chen, Yin-Qiao Chang, Che-Ming Li, Jann-Long Chern, Chih-Wei Huang
TL;DR
VKFPos tackles monocular 6DoF positioning by fusing learning-based absolute and relative pose estimates within a probabilistic EKF framework under variational Bayesian inference. It decomposes the posterior into APR and RPR components, with each branch predicting pose means and diagonal covariances in $SE(3)$, and uses these covariances to weight training losses and EKF updates. The approach yields competitive single-shot accuracy on indoor and outdoor datasets and surpasses temporal APR and model-based integrations when sequential imagery is available, while maintaining robust covariance estimates for stability. Experimental results on 7-Scenes and Oxford RobotCar demonstrate improved translation and rotation accuracy and highlight VKFPos’s robustness and real-time suitability for autonomous navigation and robotics.
Abstract
This paper addresses the challenges in learning-based monocular positioning by proposing VKFPos, a novel approach that integrates Absolute Pose Regression (APR) and Relative Pose Regression (RPR) via an Extended Kalman Filter (EKF) within a variational Bayesian inference framework. Our method shows that the essential posterior probability of the monocular positioning problem can be decomposed into APR and RPR components. This decomposition is embedded in the deep learning model by predicting covariances in both APR and RPR branches, allowing them to account for associated uncertainties. These covariances enhance the loss functions and facilitate EKF integration. Experimental evaluations on both indoor and outdoor datasets show that the single-shot APR branch achieves accuracy on par with state-of-the-art methods. Furthermore, for temporal positioning, where consecutive images allow for RPR and EKF integration, VKFPos outperforms temporal APR and model-based integration methods, achieving superior accuracy.
