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Geo-Localization Based on Dynamically Weighted Factor-Graph

IEEE Robotics and Automation Letters + 2024 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)

Miguel Ángel Muñoz-Bañón, Alejandro Olivas, Edison Velasco-Sánchez,
Francisco A. Candelas, Fernando Torres
Group of Automation, Robotics and Computer Vision (AUROVA) - University of Alicante
Diagram Robust Single Object Tracking and Following by Fusion Strategy

Handcrafted feature-based maps obtained from aerial geo-referenced imagery are usually sparse and ambiguous:

  1. Ambiguity mitigation: We provide a factor graph that weights the residuals depending on the information in the data (see pipeline). In this way, when the data is ambiguous, we can hold the localization, providing more weight to the prior trajectory (odometry + GPS-corrected) and less to the data association.
  2. Sparsity mitigation: When the data is sparse, it is possible to lose data association parts. When this occurs, the SOTA methods converge to the prior (odometry + GPS). However, due to our GPS error estimation, we can hold the localization by the corrected prior (odometry + GPS-corrected).

Depiction of mitigation for the drawbacks (1) and (2)

Aerial image
Global map
Robot BLUE

Experiments setup: (Left) Aerial geo-referenced image - (Center) Ground boundaries map (from aerial image) + 4 drove circuits - (Right) BLUE robot (UGV), used for the experiments

Paper Abstract

Feature-based geo-localization relies on associating features extracted from aerial imagery with those detected by the vehicle's sensors. This requires that the type of landmarks must be observable from both sources. This lack of variety of feature types generates poor representations that lead to outliers and deviations produced by ambiguities and lack of detections, respectively. To mitigate these drawbacks, in this letter, we present a dynamically weighted factor graph model for the vehicle's trajectory estimation. The weight adjustment in this implementation depends on information quantification in the detections performed using a LiDAR sensor. Also, a prior (GNSS-based) error estimation is included in the model. Then, when the representation becomes ambiguous or sparse, the weights are dynamically adjusted to rely on the corrected prior trajectory, mitigating outliers and deviations in this way. We compare our method against state-of-the-art geo-localization ones in a challenging and ambiguous environment, where we also cause detection losses. We demonstrate mitigation of the mentioned drawbacks where the other methods fail.

BibTeX


        @article{munoz2024geolocalization,
          title={Geo-Localization Based on Dynamically Weighted Factor-Graph},
          author={Muñoz-Bañón, Miguel Ángel and Olivas, Alejandro and Velasco-Sánchez, Edison and Candelas, Francisco A. and Torres, Fernando},
          journal={IEEE Robotics and Automation Letters},
          volume={9},
          number={6},
          pages={5599--5606},
          year={2024},
          doi={10.1109/LRA.2024.3396055},
          publisher={IEEE}
        }