Uploaded May 2021 | Updated September 2026, 3 weeks ago
RA-L/ICRA 2021
"Unified Multi-Modal Landmark Tracking for Tightly Coupled Lidar-Visual-Inertial Odometry"
David Wisth, Marco Camurri, Sandipan Das, Maurice Fallon
Paper link: arxiv.org/abs/2011.06838
VILENS website: ori.ox.ac.uk/labs/drs/vilens-tightly-fused-multi-sensor-odometry
Abstract:
We present an efficient multi-sensor odometry system
for mobile platforms that jointly optimizes visual, lidar, and
inertial information within a single integrated factor graph. This
runs in real-time at full framerate using fixed lag smoothing.
To perform such tight integration, a new method to extract 3D
line and planar primitives from lidar point clouds is presented.
This approach overcomes the suboptimality of typical frame-to-
frame tracking methods by treating the primitives as landmarks
and tracking them over multiple scans. True integration of
lidar features with standard visual features and IMU is made
possible using a subtle passive synchronization of lidar and
camera frames. The lightweight formulation of the 3D features
allows for real-time execution on a single CPU. Our proposed
system has been tested on a variety of platforms and scenarios,
including underground exploration with a legged robot and
outdoor scanning with a dynamically moving handheld device,
for a total duration of 96 min and 2.4 km traveled distance. In
these test sequences, using only one exteroceptive sensor leads
to failure due to either underconstrained geometry (affecting
lidar) or textureless areas caused by aggressive lighting changes
(affecting vision). In these conditions, our factor graph naturally
uses the best information available from each sensor modality
without any hard switches.
RA-L/ICRA 2021
"Unified Multi-Modal Landmark Tracking for Tightly Coupled Lidar-Visual-Inertial Odometry"
David Wisth, Marco Camurri, Sandipan Das, Maurice Fallon
Paper link: arxiv.org/abs/2011.06838
VILENS website: ori.ox.ac.uk/labs/drs/vilens-tightly-fused-multi-sensor-odometry
Abstract:
We present an efficient multi-sensor odometry system
for mobile platforms that jointly optimizes visual, lidar, and
inertial information within a single integrated factor graph. This
runs in real-time at full framerate using fixed lag smoothing.
To perform such tight integration, a new method to extract 3D
line and planar primitives from lidar point clouds is presented.
This approach overcomes the suboptimality of typical frame-to-
frame tracking methods by treating the primitives as landmarks
and tracking them over multiple scans. True integration of
lidar features with standard visual features and IMU is made
possible using a subtle passive synchronization of lidar and
camera frames. The lightweight formulation of the 3D features
allows for real-time execution on a single CPU. Our proposed
system has been tested on a variety of platforms and scenarios,
including underground exploration with a legged robot and
outdoor scanning with a dynamically moving handheld device,
for a total duration of 96 min and 2.4 km traveled distance. In
these test sequences, using only one exteroceptive sensor leads
to failure due to either underconstrained geometry (affecting
lidar) or textureless areas caused by aggressive lighting changes
(affecting vision). In these conditions, our factor graph naturally
uses the best information available from each sensor modality
without any hard switches.

![[Presentation] Elastic and Efficient LiDAR Reconstruction for Large-Scale Exploration Tasks
Video presentation of the article https://arxiv.org/abs/2010.09232
Elastic and Efficient LiDAR Reconstruction for Large-Scale Exploration Tasks
Yiduo Wang, Nils Funk, Milad Ramezani, Sotiris Papatheodorou, Marija Popovic, Marco Camurri, Stefan Leutenegger, Maurice Fallon
IEEE International Conference on Robotics and Automation (ICRA), 2021
Abstract:
We present an efficient, elastic 3D LiDAR reconstruction framework which can reconstruct up to maximum LiDAR ranges (60 m) at multiple frames per second, thus enabling robot exploration in large-scale environments. Our approach only requires a CPU. We focus on three main challenges of large-scale reconstruction: integration of long-range LiDAR scans at high frequency, the capacity to deform the reconstruction after loop closures are detected, and scalability for long-duration exploration. Our system extends upon a state-of-the-art efficient RGB-D volumetric reconstruction technique, called supereight, to support LiDAR scans and a newly developed submapping technique to allow for dynamic correction of the 3D reconstruction. We then introduce a novel pose graph clustering and submap fusion feature to make the proposed system more scalable for large environments. We evaluate the performance using two public datasets including outdoor exploration with a handheld device and a drone, and with a mobile robot exploring an underground room network. Experimental results demonstrate that our system can reconstruct at 3 Hz with 60 m sensor range and ~5 cm resolution, while state-of-the-art approaches can only reconstruct to 25 cm resolution or 20 m range at the same frequency. [Presentation] Elastic and Efficient LiDAR Reconstruction for Large-Scale Exploration Tasks](https://i.ytimg.com/vi/mNMdlNkWeVM/mqdefault.jpg)








![OASIS-Map: Object-Level Change Detection in Multi-Session Mapping using Semantic Correspondence
[Abstract]
Map representations which are consistent across repeated visits to a real-world semi-static environment are very useful for long-term robotic inspection. In such settings, the scene may evolve while the robot is absent, with objects appearing, disappearing, moving, or being replaced, quickly making a static map outdated. Existing change-detection methods reason through geometry, category-level semantics, or object persistence. However, achieving reliable object association across revisits remains a key challenge, especially under partial views, occlusion, and imperfect segmentation. In this work, we propose OASIS-Map, a multi-session mapping system that maintains a spatio-temporally consistent object-level map by establishing dense patch-level semantic correspondences between temporal observations. These correspondences detect where the scene has changed and incrementally associate objects across revisits as the robot re-observes the environment. We demonstrate OASIS-Map on three challenging real-world scenarios: object rearrangements in 3RScan, visually similar car replacements in a car park, and large-scale scene changes in an outdoor market. We achieve 0.783 F1 on change detection in a car replacement scenario in a car park and 0.667 F1 on moved object association in 3RScan. https://dynamic.robots.ox.ac.uk/projects/oasis-map/
Authors: Haedam Oh, Yifu Tao, Nived Chebrolu, and Maurice Fallon
Pre-print: https://arxiv.org/abs/2607.14899 OASIS-Map: Object-Level Change Detection in Multi-Session Mapping using Semantic Correspondence](https://i.ytimg.com/vi/sfVcFEXyTG4/mqdefault.jpg)