Search Results (5)

Simultaneous Localization and Mapping (SLAM) has become a critical tool for fully autonomous driving. However, current methods suffer from inefficient data utilization and degraded navigation performance in complex and unknown environments. In this paper, an accurate and tightly coupled method of LiDAR-inertial odometry is proposed. First, a self-adaptive voxel grid filter is developed to dynamically downsample the original point clouds based on environmental feature richness, aiming to balance navigation accuracy and real-time performance. Second, keyframe factors are selected based on thresholds of translation distance, rotation angle, and time interval and then introduced into the factor graph to improve global consistency. Additionally, high-quality Global Navigation Satellite System (GNSS) factors are selected and incorporated into the factor graph through linear interpolation, thereby improving the navigation accuracy in complex and unknown environments. The proposed method is evaluated using KITTI dataset over various scales and environments. Results show that the proposed method has demonstrated very promising better results when compared with the other methods, such as ALOAM, LIO-SAM, and SC-LeGO-LOAM. Especially in urban scenes, the trajectory accuracy of the proposed method has been improved by 33.13%, 57.56%, and 58.4%, respectively, illustrating excellent navigation and positioning capabilities. Full article

Achieving high-precision anomaly detection with incomplete sensor data is a critical challenge in industrial automation and intelligent manufacturing. This incompleteness often results from sensor failures, environmental interference, occlusions, or acquisition cost constraints. This study explicitly targets both types of incompleteness commonly encountered in industrial multimodal inspection: (i) incomplete sensor data within a given modality, such as partial point cloud loss or image degradation, and (ii) incomplete modalities, where one sensing channel (RGB or 3D) is entirely unavailable. By jointly addressing intra-modal incompleteness and cross-modal absence within a unified cross-distillation framework, our approach enhances anomaly detection robustness under both conditions. First, a teacher–student cross-modal distillation mechanism enables robust feature learning from both RGB and 3D modalities, allowing the student network to accurately detect anomalies even when a modality is missing during inference. Second, a dynamic voxel resolution adjustment with edge-retention strategy alleviates the computational burden of 3D point cloud processing while preserving crucial geometric features. By jointly enhancing robustness to missing modalities and improving computational efficiency, our method offers a resilient and practical solution for anomaly detection in real-world manufacturing scenarios. Extensive experiments demonstrate that the proposed method achieves both high robustness and efficiency across multiple industrial scenarios, establishing new state-of-the-art performance that surpasses existing approaches in both accuracy and speed. This method provides a robust solution for high-precision perception under complex detection conditions, significantly enhancing the feasibility of deploying anomaly detection systems in real industrial environments. Full article

Accurate 3D object detection is becoming increasingly vital for the development of robust perception systems, particularly in applications such as autonomous driving vehicles and robotic systems. Many existing approaches rely on bird’s eye view (BEV) feature maps to facilitate multi-modal interaction, as BEV representations enable efficient operations. However, the inherent sparsity of LiDAR BEV features often leads to misalignment with the dense semantic information in camera images, resulting in suboptimal fusion quality and degraded detection performance, especially in complex and dynamic environments. To mitigate these issues, this paper proposes a novel multi-dimension semantic–spatial feature fusion (MDFusion) method that combines LiDAR and image features in 2D and 3D spaces. Specifically, image semantic features are extracted using the DeepLabV3 segmentation network, which captures rich contextual information and is aligned with LiDAR point cloud voxel features through a summation operation to achieve precise semantic fusion. Additionally, LiDAR BEV features are fused with downsampled image features in 2D space via concatenation and spatially adaptive dilated convolution. The mechanism dynamically adjusts to the spatial characteristics of the data, ensuring robust feature integration. Extensive experiments on the KITTI and ONCE datasets demonstrate that our method achieves competitive performance in complex scenes, significantly improving the multi-modal fusion quality and detection accuracy while maintaining computational efficiency. Full article

In response to the challenge of handling large-scale 3D point cloud data, downsampling is a common approach, yet it often leads to the problem of feature loss. We present a dynamic downsampling algorithm for 3D point cloud maps based on an improved voxel filtering approach. The algorithm consists of two modules, namely, dynamic downsampling and point cloud edge extraction. The former adapts voxel downsampling according to the features of the point cloud, while the latter preserves edge information within the 3D point cloud map. Comparative experiments with voxel downsampling, grid downsampling, clustering-based downsampling, random downsampling, uniform downsampling, and farthest-point downsampling were conducted. The proposed algorithm exhibited favorable downsampling simplification results, with a processing time of 0.01289 s and a simplification rate of 91.89%. Additionally, it demonstrated faster downsampling speed and showcased improved overall performance. This enhancement not only benefits productivity but also highlights the system’s efficiency and effectiveness. Full article

Traditional LiDAR odometry (LO) systems mainly leverage geometric information obtained from the traversed surroundings to register lazer scans and estimate LiDAR ego-motion, while they may be unreliable in dynamic or degraded environments. This paper proposes InTEn-LOAM, a low-drift and robust LiDAR odometry and mapping method that fully exploits implicit information of lazer sweeps (i.e., geometric, intensity and temporal characteristics). The specific content of this work includes method innovation and experimental verification. With respect to method innovation, we propose the cylindrical-image-based feature extraction scheme, which makes use of the characteristic of uniform spatial distribution of lazer points to boost the adaptive extraction of various types of features, i.e., ground, beam, facade and reflector. We propose a novel intensity-based point registration algorithm and incorporate it into the LiDAR odometry, enabling the LO system to jointly estimate the LiDAR ego-motion using both geometric and intensity feature points. To eliminate the interference of dynamic objects, we propose a temporal-based dynamic object removal approach to filter them out in the resulting points map. Moreover, the local map is organized and downsampled using a temporal-related voxel grid filter to maintain the similarity between the current scan and the static local map. With respect to experimental verification, extensive tests are conducted on both simulated and real-world datasets. The results show that the proposed method achieves similar or better accuracy with respect to the state-of-the-art in normal driving scenarios and outperforms geometric-based LO in unstructured environments. Full article