InterKey: Cross-modal Intersection Keypoints for Global Localization on OpenStreetMap

Reliable global localization is critical for autonomous vehicles, especially in environments where GNSS is degraded or unavailable, such as urban canyons and tunnels. Although high-definition (HD) maps provide accurate priors, the cost of data collection, map construction, and maintenance limits scalability. OpenStreetMap (OSM) offers a free and globally available alternative, but its coarse abstraction poses challenges for matching with sensor data. We propose InterKey, a cross-modal framework that leverages road intersections as distinctive landmarks for global localization. Our method constructs compact binary descriptors by jointly encoding road and building imprints from point clouds and OSM. To bridge modality gaps, we introduce discrepancy mitigation, orientation determination, and area-equalized sampling strategies, enabling robust cross-modal matching. Experiments on the KITTI dataset demonstrate that InterKey achieves state-of-the-art accuracy, outperforming recent baselines by a large margin. The framework generalizes to sensors that can produce dense structural point clouds, offering a scalable and cost-effective solution for robust vehicle localization.

OccCylindrical: Multi-Modal Fusion with Cylindrical Representation for 3D Semantic Occupancy Prediction

The safe operation of autonomous vehicles (AVs) is highly dependent on their understanding of the surroundings. For this, the task of 3D semantic occupancy prediction divides the space around the sensors into voxels, and labels each voxel with both occupancy and semantic information. Recent perception models have used multisensor fusion to perform this task. However, existing multisensor fusion-based approaches focus mainly on using sensor information in the Cartesian coordinate system. This ignores the distribution of the sensor readings, leading to a loss of fine-grained details and performance degradation. In this paper, we propose OccCylindrical that merges and refines the different modality features under cylindrical coordinates. Our method preserves more fine-grained geometry detail that leads to better performance. Extensive experiments conducted on the nuScenes dataset, including challenging rainy and nighttime scenarios, confirm our approach's effectiveness and state-of-the-art performance. The code will be available at: https://github.com/DanielMing123/OccCylindrical

InterLoc: LiDAR-based Intersection Localization using Road Segmentation with Automated Evaluation Method

Intersections are geometric and functional key points in every road network. They offer strong landmarks to correct GNSS dropouts and anchor new sensor data in up-to-date maps. Despite that importance, intersection detectors either ignore the rich semantic information already computed onboard or depend on scarce, hand-labeled intersection datasets. To close that gap, this paper presents a LiDAR-based method for intersection detection that (i) fuses semantic road segmentation with vehicle localization to detect intersection candidates in a bird's eye view (BEV) representation and (ii) refines those candidates by analyzing branch topology with a least squares formulation. To evaluate our method, we introduce an automated benchmarking pipeline that pairs detections with OpenStreetMap (OSM) intersection nodes using precise GNSS/INS ground-truth poses. Tested on eight SemanticKITTI sequences, the approach achieves a mean localization error of 1.9 m, 89% precision, and 77% recall at a 5 m tolerance, outperforming the latest learning-based baseline. Moreover, the method is robust to segmentation errors higher than those of the benchmark model, demonstrating its applicability in the real world.