Uploaded July 2025 | Updated September 2026, 1 week ago
Video introducing our paper " Online 6DoF Global Localisation in Forests using Semantically-Guided Re-Localisation and Cross-View Factor-Graph Optimisation", accepted at IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2025).
This work presents FGLoc6D, a novel approach for robust global localisation and online 6DoF pose estimation of ground robots in forest environments by leveraging deep semantically-guided re-localisation and cross-view factor graph optimisation. The proposed method addresses the challenges of aligning aerial and ground data for pose estimation, which is crucial for accurate point-to-point navigation in GPS-degraded environments. By integrating information from both perspectives into a factor graph framework, our approach effectively estimates the robot’s global position and orientation. Additionally, we enhance the repeatability of deep-learned keypoints for metric localisation in forests by incorporating a semantically-guided regression loss. This loss encourages greater attention to wooden structures, e.g., tree trunks, which serve as stable and distinguishable features, thereby improving the consistency of keypoints and increasing the success rate of global registration, a process we refer to as re-localisation. The re-localisation module along with the factor-graph structure, populated by odometry and ground-to-aerial factors over time, allows global localisation under dense canopies. We validate the performance of our method through extensive experiments in three forest scenarios, demonstrating its global localisation capability and superiority over alternative state-of-the-art in terms of accuracy and robustness in these challenging environments. Experimental results show that our proposed method can achieve drift-free localisation with bounded positioning errors, ensuring reliable and safe robot navigation through dense forests.
Paper: arxiv.org/abs/2409.16680
Video introducing our paper " Online 6DoF Global Localisation in Forests using Semantically-Guided Re-Localisation and Cross-View Factor-Graph Optimisation", accepted at IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS 2025).
This work presents FGLoc6D, a novel approach for robust global localisation and online 6DoF pose estimation of ground robots in forest environments by leveraging deep semantically-guided re-localisation and cross-view factor graph optimisation. The proposed method addresses the challenges of aligning aerial and ground data for pose estimation, which is crucial for accurate point-to-point navigation in GPS-degraded environments. By integrating information from both perspectives into a factor graph framework, our approach effectively estimates the robot’s global position and orientation. Additionally, we enhance the repeatability of deep-learned keypoints for metric localisation in forests by incorporating a semantically-guided regression loss. This loss encourages greater attention to wooden structures, e.g., tree trunks, which serve as stable and distinguishable features, thereby improving the consistency of keypoints and increasing the success rate of global registration, a process we refer to as re-localisation. The re-localisation module along with the factor-graph structure, populated by odometry and ground-to-aerial factors over time, allows global localisation under dense canopies. We validate the performance of our method through extensive experiments in three forest scenarios, demonstrating its global localisation capability and superiority over alternative state-of-the-art in terms of accuracy and robustness in these challenging environments. Experimental results show that our proposed method can achieve drift-free localisation with bounded positioning errors, ensuring reliable and safe robot navigation through dense forests.
Paper: arxiv.org/abs/2409.16680




![Large-Scale 2D Laser-Based SLAM
Simultaneous Localization and Mapping (SLAM) is a technique in which the trajectory of a sensor and a map are estimated simultaneously from sensor data. This video demonstrates the 2D SLAM solution developed by CSIRO which enables city-scale mapping in real-time. The solution uses lidar, which is a method of sensing that employs (infrared) laser to measure ranges to surfaces based on time of flight.
Here, two 2D SICK LMS291 lidars are placed on the roof of a vehicle, which is driven around Brisbane, Australia at traffic speeds. There are no other sensors utilized; in particular, no GPS, inertial sensors, or wheel encoders are required. The SICK lidars can measure to a maximum of about 80m, depending on the surface properties.
The local mapping is performed using an EKF-based scan-matching algorithm. Scalability is achieved by using the Atlas framework. Loop closures are detected using a place recognition solution based on regional keypoints extracted from the laser data.
The overall result is map consisting of data collected in multiple datasets over the course of more than one year. The total distance traveled is 165km, and the top speed is 90km/h. The largest loop in the dataset is over 40km. Data collection occurred at various times of day, including peak traffic hours. The appearance of some areas changed dramatically over the data acquisition period due to seasonal variability of vegetation, and major construction on some of the roads.
Relevant Publications (links and pdfs available at http://ict.csiro.au/staff/Robert.Zlot/publications.php ):
[1] https://db.tt/OqZyYWEo or http://dx.doi.org/10.1016/j.robot.2009.07.009 (pdf)
M. Bosse and R. Zlot, Keypoint Design and Evaluation for Place Recognition in 2D Lidar Maps, Robotics and Autonomous Systems, 57(12), December 2009.
[2] https://db.tt/jdmpM2rC or http://dx.doi.org/10.1177/0278364908091366 (pdf)
M. Bosse and R. Zlot, Map Matching and Data Association for Large-Scale Two-dimensional Laser-based SLAM, International Journal of Robotics Research, 27(6), June, 2008.
[3] https://db.tt/0hJB9Ouh or http://dx.doi.org/10.1007/978-3-642-00196-3_42 (pdf)
R. Zlot and M. Bosse, Place Recognition using Keypoint Similarities in 2D Lidar Maps, International Symposium on Experimental Robotics, July, 2008.
More information at:
http://research.ict.csiro.au/research/labs/autonomous-systems/field-robotics/mapping-and-localisation Large-Scale 2D Laser-Based SLAM](https://i.ytimg.com/vi/o1EUWlv5yv0/mqdefault.jpg)



![[RA-L/ICRA 2018] Complementary Perception for Handheld SLAM
We present a novel method for mapping general 3D environments, where sufficient geometric or visual information is not everywhere guaranteed and where the device motion is unconstrained as with handheld systems. The continuous-time SLAM algorithm integrates a lidar, camera and inertial measurement unit in a complementary fashion whereby all sensors contribute constraints to the optimization. The proposed algorithm is designed to expand the domain of mappable environments and therefore increase the reliability and utility of general purpose mobile mapping. A key component of the proposed algorithm is the incorporation of depth uncertainty into visual features, which is effective for noisy surfaces and allows features with and without depth estimates to be modeled in a unified manner. Results demonstrate a wider mappable domain on challenging environments compared to state-of-the-art lidar or vision based localization and mapping algorithms. [RA-L/ICRA 2018] Complementary Perception for Handheld SLAM](https://i.ytimg.com/vi/q8NAsqOH2C0/mqdefault.jpg)

