它得到了很好的认识到，从深度感知的LIDAR点云和语义富有的立体图像中融合互补信息将有利于3D对象检测。然而，探索稀疏3D点和密集2D像素之间固有的不自然相互作用并不重要。为了简化这种困难，最近的建议通常将3D点投影到2D图像平面上以对图像数据进行采样，然后聚合点处的数据。然而，这种方法往往遭受点云和RGB图像的分辨率之间的不匹配，导致次优性能。具体地，作为多模态数据聚合位置的稀疏点导致高分辨率图像的严重信息丢失，这反过来破坏了多传感器融合的有效性。在本文中，我们呈现VPFNET - 一种新的架构，可以在“虚拟”点处巧妙地对齐和聚合点云和图像数据。特别地，它们的密度位于3D点和2D像素的密度之间，虚拟点可以很好地桥接两个传感器之间的分辨率间隙，从而保持更多信息以进行处理。此外，我们还研究了可以应用于点云和RGB图像的数据增强技术，因为数据增强对迄今为止对3D对象探测器的贡献不可忽略。我们对Kitti DataSet进行了广泛的实验，与最先进的方法相比，观察到了良好的性能。值得注意的是，我们的VPFNET在KITTI测试集上实现了83.21 \％中等3D AP和91.86 \％适度的BEV AP，自2021年5月21日起排名第一。网络设计也考虑了计算效率 - 我们可以实现FPS 15对单个NVIDIA RTX 2080TI GPU。该代码将用于复制和进一步调查。

3D object detection from LiDAR point cloud is a challenging problem in 3D scene understanding and has many practical applications. In this paper, we extend our preliminary work PointRCNN to a novel and strong point-cloud-based 3D object detection framework, the part-aware and aggregation neural network (Part-A 2 net). The whole framework consists of the part-aware stage and the part-aggregation stage. Firstly, the part-aware stage for the first time fully utilizes free-of-charge part supervisions derived from 3D ground-truth boxes to simultaneously predict high quality 3D proposals and accurate intra-object part locations. The predicted intra-object part locations within the same proposal are grouped by our new-designed RoI-aware point cloud pooling module, which results in an effective representation to encode the geometry-specific features of each 3D proposal. Then the part-aggregation stage learns to re-score the box and refine the box location by exploring the spatial relationship of the pooled intra-object part locations. Extensive experiments are conducted to demonstrate the performance improvements from each component of our proposed framework. Our Part-A 2 net outperforms all existing 3D detection methods and achieves new state-of-the-art on KITTI 3D object detection dataset by utilizing only the LiDAR point cloud data. Code is available at https://github.com/sshaoshuai/PointCloudDet3D.

最近，融合了激光雷达点云和相机图像，提高了3D对象检测的性能和稳健性，因为这两种方式自然具有强烈的互补性。在本文中，我们通过引入新型级联双向融合〜（CB融合）模块和多模态一致性〜（MC）损耗来提出用于多模态3D对象检测的EPNet ++。更具体地说，所提出的CB融合模块提高点特征的丰富语义信息，以级联双向交互融合方式具有图像特征，导致更全面且辨别的特征表示。 MC损失明确保证预测分数之间的一致性，以获得更全面且可靠的置信度分数。基蒂，JRDB和Sun-RGBD数据集的实验结果展示了通过最先进的方法的EPNet ++的优越性。此外，我们强调一个关键但很容易被忽视的问题，这是探讨稀疏场景中的3D探测器的性能和鲁棒性。广泛的实验存在，EPNet ++优于现有的SOTA方法，在高稀疏点云壳中具有显着的边距，这可能是降低LIDAR传感器的昂贵成本的可用方向。代码将来会发布。

近年来，由于深度学习技术的发展，LiDar Point Clouds的3D对象检测取得了长足的进步。尽管基于体素或基于点的方法在3D对象检测中很受欢迎，但它们通常涉及耗时的操作，例如有关体素的3D卷积或点之间的球查询，从而使所得网络不适合时间关键应用程序。另一方面，基于2D视图的方法具有较高的计算效率，而通常比基于体素或基于点的方法获得的性能低。在这项工作中，我们提出了一个基于实时视图的单阶段3D对象检测器，即CVFNET完成此任务。为了在苛刻的效率条件下加强跨视图的学习，我们的框架提取了不同视图的特征，并以有效的渐进式方式融合了它们。我们首先提出了一个新颖的点范围特征融合模块，该模块在多个阶段深入整合点和范围视图特征。然后，当将所获得的深点视图转换为鸟类视图时，特殊的切片柱旨在很好地维护3D几何形状。为了更好地平衡样品比率，提出了一个稀疏的柱子检测头，将检测集中在非空网上。我们对流行的Kitti和Nuscenes基准进行了实验，并以准确性和速度来实现最先进的性能。

具有多传感器的3D对象检测对于自主驾驶和机器人技术的准确可靠感知系统至关重要。现有的3D探测器通过采用两阶段范式来显着提高准确性，这仅依靠激光点云进行3D提案的细化。尽管令人印象深刻，但点云的稀疏性，尤其是对于遥远的点，使得仅激光雷达的完善模块难以准确识别和定位对象。要解决这个问题，我们提出了一种新颖的多模式两阶段方法FusionRcnn，有效，有效地融合了感兴趣区域（ROI）的点云和摄像头图像。 FusionRcnn自适应地整合了LiDAR的稀疏几何信息和统一注意机制中相机的密集纹理信息。具体而言，它首先利用RoiPooling获得具有统一大小的图像集，并通过在ROI提取步骤中的建议中采样原始点来获取点设置；然后利用模式内的自我注意力来增强域特异性特征，此后通过精心设计的跨注意事项融合了来自两种模态的信息。FusionRCNN从根本上是插件，并支持不同的单阶段方法与不同的单阶段方法。几乎没有建筑变化。对Kitti和Waymo基准测试的广泛实验表明，我们的方法显着提高了流行探测器的性能。可取，FusionRCNN在Waymo上的FusionRCNN显着提高了强大的第二基线，而Waymo上的MAP则超过6.14％，并且优于竞争两阶段方法的表现。代码将很快在https://github.com/xxlbigbrother/fusion-rcnn上发布。

在鸟眼中学习强大的表现（BEV），以进行感知任务，这是趋势和吸引行业和学术界的广泛关注。大多数自动驾驶算法的常规方法在正面或透视视图中执行检测，细分，跟踪等。随着传感器配置变得越来越复杂，从不同的传感器中集成了多源信息，并在统一视图中代表功能至关重要。 BEV感知继承了几个优势，因为代表BEV中的周围场景是直观和融合友好的。对于BEV中的代表对象，对于随后的模块，如计划和/或控制是最可取的。 BEV感知的核心问题在于（a）如何通过从透视视图到BEV来通过视图转换来重建丢失的3D信息； （b）如何在BEV网格中获取地面真理注释； （c）如何制定管道以合并来自不同来源和视图的特征； （d）如何适应和概括算法作为传感器配置在不同情况下各不相同。在这项调查中，我们回顾了有关BEV感知的最新工作，并对不同解决方案进行了深入的分析。此外，还描述了该行业的BEV方法的几种系统设计。此外，我们推出了一套完整的实用指南，以提高BEV感知任务的性能，包括相机，激光雷达和融合输入。最后，我们指出了该领域的未来研究指示。我们希望该报告能阐明社区，并鼓励对BEV感知的更多研究。我们保留一个活跃的存储库来收集最新的工作，并在https://github.com/openperceptionx/bevperception-survey-recipe上提供一包技巧的工具箱。

We present a novel and high-performance 3D object detection framework, named PointVoxel-RCNN (PV-RCNN), for accurate 3D object detection from point clouds. Our proposed method deeply integrates both 3D voxel Convolutional Neural Network (CNN) and PointNet-based set abstraction to learn more discriminative point cloud features. It takes advantages of efficient learning and high-quality proposals of the 3D voxel CNN and the flexible receptive fields of the PointNet-based networks. Specifically, the proposed framework summarizes the 3D scene with a 3D voxel CNN into a small set of keypoints via a novel voxel set abstraction module to save follow-up computations and also to encode representative scene features. Given the highquality 3D proposals generated by the voxel CNN, the RoIgrid pooling is proposed to abstract proposal-specific features from the keypoints to the RoI-grid points via keypoint set abstraction with multiple receptive fields. Compared with conventional pooling operations, the RoI-grid feature points encode much richer context information for accurately estimating object confidences and locations. Extensive experiments on both the KITTI dataset and the Waymo Open dataset show that our proposed PV-RCNN surpasses state-of-the-art 3D detection methods with remarkable margins by using only point clouds. Code is available at https://github.com/open-mmlab/OpenPCDet.

LiDAR-based 3D Object detectors have achieved impressive performances in many benchmarks, however, multisensors fusion-based techniques are promising to further improve the results. PointPainting, as a recently proposed framework, can add the semantic information from the 2D image into the 3D LiDAR point by the painting operation to boost the detection performance. However, due to the limited resolution of 2D feature maps, severe boundary-blurring effect happens during re-projection of 2D semantic segmentation into the 3D point clouds. To well handle this limitation, a general multimodal fusion framework MSF has been proposed to fuse the semantic information from both the 2D image and 3D points scene parsing results. Specifically, MSF includes three main modules. First, SOTA off-the-shelf 2D/3D semantic segmentation approaches are employed to generate the parsing results for 2D images and 3D point clouds. The 2D semantic information is further re-projected into the 3D point clouds with calibrated parameters. To handle the misalignment between the 2D and 3D parsing results, an AAF module is proposed to fuse them by learning an adaptive fusion score. Then the point cloud with the fused semantic label is sent to the following 3D object detectors. Furthermore, we propose a DFF module to aggregate deep features in different levels to boost the final detection performance. The effectiveness of the framework has been verified on two public large-scale 3D object detection benchmarks by comparing with different baselines. The experimental results show that the proposed fusion strategies can significantly improve the detection performance compared to the methods using only point clouds and the methods using only 2D semantic information. Most importantly, the proposed approach significantly outperforms other approaches and sets new SOTA results on the nuScenes testing benchmark.

Aiming at highly accurate object detection for connected and automated vehicles (CAVs), this paper presents a Deep Neural Network based 3D object detection model that leverages a three-stage feature extractor by developing a novel LIDAR-Camera fusion scheme. The proposed feature extractor extracts high-level features from two input sensory modalities and recovers the important features discarded during the convolutional process. The novel fusion scheme effectively fuses features across sensory modalities and convolutional layers to find the best representative global features. The fused features are shared by a two-stage network: the region proposal network (RPN) and the detection head (DH). The RPN generates high-recall proposals, and the DH produces final detection results. The experimental results show the proposed model outperforms more recent research on the KITTI 2D and 3D detection benchmark, particularly for distant and highly occluded instances.

基于LIDAR的传感驱动器电流自主车辆。尽管进展迅速，但目前的激光雷达传感器在分辨率和成本方面仍然落后于传统彩色相机背后的二十年。对于自主驾驶，这意味着靠近传感器的大物体很容易可见，但远方或小物体仅包括一个测量或两个。这是一个问题，尤其是当这些对象结果驾驶危险时。另一方面，在车载RGB传感器中清晰可见这些相同的对象。在这项工作中，我们提出了一种将RGB传感器无缝熔化成基于LIDAR的3D识别方法。我们的方法采用一组2D检测来生成密集的3D虚拟点，以增加否则稀疏的3D点云。这些虚拟点自然地集成到任何基于标准的LIDAR的3D探测器以及常规激光雷达测量。由此产生的多模态检测器简单且有效。大规模NUSCENES数据集的实验结果表明，我们的框架通过显着的6.6地图改善了强大的中心点基线，并且优于竞争融合方法。代码和更多可视化可在https://tianweiy.github.io/mvp/上获得

In this paper, we propose a novel 3D object detector that can exploit both LIDAR as well as cameras to perform very accurate localization. Towards this goal, we design an end-to-end learnable architecture that exploits continuous convolutions to fuse image and LIDAR feature maps at different levels of resolution. Our proposed continuous fusion layer encode both discrete-state image features as well as continuous geometric information. This enables us to design a novel, reliable and efficient end-to-end learnable 3D object detector based on multiple sensors. Our experimental evaluation on both KITTI as well as a large scale 3D object detection benchmark shows significant improvements over the state of the art.

In this paper we propose to exploit multiple related tasks for accurate multi-sensor 3D object detection. Towards this goal we present an end-to-end learnable architecture that reasons about 2D and 3D object detection as well as ground estimation and depth completion. Our experiments show that all these tasks are complementary and help the network learn better representations by fusing information at various levels. Importantly, our approach leads the KITTI benchmark on 2D, 3D and bird's eye view object detection, while being real-time. * Equal contribution.† Work done as part of Uber AI Residency program.

由于其在各种领域的广泛应用，3D对象检测正在接受行业和学术界的增加。在本文中，我们提出了从点云的3D对象检测的基于角度基于卷曲区域的卷积神经网络（PV-RCNNS）。首先，我们提出了一种新颖的3D探测器，PV-RCNN，由两个步骤组成：Voxel-to-keyPoint场景编码和Keypoint-to-Grid ROI特征抽象。这两个步骤深入地将3D体素CNN与基于点的集合的集合进行了集成，以提取辨别特征。其次，我们提出了一个先进的框架，PV-RCNN ++，用于更高效和准确的3D对象检测。它由两个主要的改进组成：有效地生产更多代表性关键点的划分的提案中心策略，以及用于更好地聚合局部点特征的vectorpool聚合，具有更少的资源消耗。通过这两种策略，我们的PV-RCNN ++比PV-RCNN快2倍，同时还在具有150米* 150M检测范围内的大型Waymo Open DataSet上实现更好的性能。此外，我们提出的PV-RCNNS在Waymo Open DataSet和高竞争力的基蒂基准上实现最先进的3D检测性能。源代码可在https://github.com/open-mmlab/openpcdet上获得。

两阶段探测器在3D对象检测中已广受欢迎。大多数两阶段的3D检测器都使用网格点，体素电网或第二阶段的ROI特征提取的采样关键点。但是，这种方法在处理不均匀分布和稀疏的室外点方面效率低下。本文在三个方面解决了这个问题。 1）动态点聚集。我们建议补丁搜索以快速在本地区域中为每个3D提案搜索点。然后，将最远的体素采样采样用于均匀采样点。特别是，体素尺寸沿距离变化，以适应点的不均匀分布。 2）Ro-Graph Poling。我们在采样点上构建本地图，以通过迭代消息传递更好地模型上下文信息和地雷关系。 3）视觉功能增强。我们引入了一种简单而有效的融合策略，以补偿具有有限语义提示的稀疏激光雷达点。基于这些模块，我们将图形R-CNN构建为第二阶段，可以将其应用于现有的一阶段检测器，以始终如一地提高检测性能。广泛的实验表明，图R-CNN的表现优于最新的3D检测模型，而Kitti和Waymo Open DataSet的差距很大。我们在Kitti Bev汽车检测排行榜上排名第一。代码将在\ url {https://github.com/nightmare-n/graphrcnn}上找到。

This paper aims at high-accuracy 3D object detection in autonomous driving scenario. We propose Multi-View 3D networks (MV3D), a sensory-fusion framework that takes both LIDAR point cloud and RGB images as input and predicts oriented 3D bounding boxes. We encode the sparse 3D point cloud with a compact multi-view representation. The network is composed of two subnetworks: one for 3D object proposal generation and another for multi-view feature fusion. The proposal network generates 3D candidate boxes efficiently from the bird's eye view representation of 3D point cloud. We design a deep fusion scheme to combine region-wise features from multiple views and enable interactions between intermediate layers of different paths. Experiments on the challenging KITTI benchmarkshow that our approach outperforms the state-of-the-art by around 25% and 30% AP on the tasks of 3D localization and 3D detection. In addition, for 2D detection, our approach obtains 14.9% higher AP than the state-of-the-art on the hard data among the LIDAR-based methods.

来自LIDAR或相机传感器的3D对象检测任务对于自动驾驶至关重要。先锋尝试多模式融合的尝试补充了稀疏的激光雷达点云，其中包括图像的丰富语义纹理信息，以额外的网络设计和开销为代价。在这项工作中，我们提出了一个名为SPNET的新型语义传递框架，以通过丰富的上下文绘画的指导来提高现有基于激光雷达的3D检测模型的性能，在推理过程中没有额外的计算成本。我们的关键设计是首先通过训练语义绘制的教师模型来利用地面真实标签中潜在的指导性语义知识，然后引导纯LIDAR网络通过不同的粒度传播模块来学习语义绘制的表示：类别：类别：类别：类别：类别：类别：类别：类别：类别：类别：类别：类别：类别：类别：类别：类别：类别：类别：类别：类别：类别：类别：类别：类别：类别：类别：类别：类别：类别：类：类别：类别：类别：类别：类别：类别：类别： - 通过，像素的传递和实例传递。实验结果表明，所提出的SPNET可以与大多数现有的3D检测框架无缝合作，其中AP增益为1〜5％，甚至在KITTI测试基准上实现了新的最新3D检测性能。代码可在以下网址获得：https：//github.com/jb892/sp​​net。

当前仅激光雷达的3D检测方法不可避免地会遭受点云的稀疏性。提出了许多多模式方法来减轻此问题，而图像和点云的不同表示使它们很难融合，从而导致次优性能。在本文中，我们提出了一个新颖的多模式框架SFD（稀疏的保险丝密度），该框架利用了从深度完成生成的伪点云来解决上述问题。与先前的工作不同，我们提出了一种新的ROI Fusion策略3D-GAF（3D网格的专注融合），以更全面地使用来自不同类型的点云的信息。具体而言，3D-GAF以网格的细心方式从两点云中融合了3D ROI功能，这更细粒度，更精确。此外，我们提出了一种登录（同步增强），以使我们的多模式框架能够利用针对仅激光雷达方法的所有数据增强方法。最后，我们为伪点云自定义有效，有效的特征提取器CPCONV（色点卷积）。它可以同时探索伪点云的2D图像特征和3D几何特征。我们的方法在Kitti Car 3D对象检测排行榜上排名最高，证明了我们的SFD的有效性。代码可在https://github.com/littlepey/sfd上找到。

Accurate detection of objects in 3D point clouds is a central problem in many applications, such as autonomous navigation, housekeeping robots, and augmented/virtual reality. To interface a highly sparse LiDAR point cloud with a region proposal network (RPN), most existing efforts have focused on hand-crafted feature representations, for example, a bird's eye view projection. In this work, we remove the need of manual feature engineering for 3D point clouds and propose VoxelNet, a generic 3D detection network that unifies feature extraction and bounding box prediction into a single stage, end-to-end trainable deep network. Specifically, VoxelNet divides a point cloud into equally spaced 3D voxels and transforms a group of points within each voxel into a unified feature representation through the newly introduced voxel feature encoding (VFE) layer. In this way, the point cloud is encoded as a descriptive volumetric representation, which is then connected to a RPN to generate detections. Experiments on the KITTI car detection benchmark show that VoxelNet outperforms the state-of-the-art LiDAR based 3D detection methods by a large margin. Furthermore, our network learns an effective discriminative representation of objects with various geometries, leading to encouraging results in 3D detection of pedestrians and cyclists, based on only LiDAR.

基于摄像头的3D对象探测器由于其更广泛的部署而欢迎其比LIDAR传感器较低。我们首先重新访问先前的立体声检测器DSGN，以表示代表3D几何和语义的立体音量构建方式。我们抛光立体声建模，并提出高级版本DSGN ++，旨在在三个主要方面增强整个2d到3D管道的有效信息流。首先，为了有效地将2D信息提高到立体声音量，我们提出了深度扫地（DPS），以允许较密集的连接并提取深度引导的特征。其次，为了掌握不同间距的功能，我们提出了一个新颖的立体声音量 - 双视立体声卷（DSV），该卷（DSV）集成了前视图和顶部视图功能，并重建了相机frustum中的子素深度。第三，随着前景区域在3D空间中的占主导地位，我们提出了一种多模式数据编辑策略-Stereo-lidar拷贝性 - 可确保跨模式对齐并提高数据效率。没有铃铛和哨子，在流行的Kitti基准测试中的各种模式设置中进行了广泛的实验表明，我们的方法始终优于所有类别的基于相机的3D检测器。代码可从https://github.com/chenyilun95/dsgn2获得。

利用多模式融合，尤其是在摄像头和激光雷达之间，对于为自动驾驶汽车构建准确且健壮的3D对象检测系统已经至关重要。直到最近，点装饰方法（在该点云中都用相机功能增强，一直是该领域的主要方法。但是，这些方法无法利用来自相机的较高分辨率图像。还提出了最近将摄像头功能投射到鸟类视图（BEV）融合空间的作品，但是它们需要预计数百万像素，其中大多数仅包含背景信息。在这项工作中，我们提出了一种新颖的方法中心功能融合（CFF），其中我们利用相机和激光雷达中心的基于中心的检测网络来识别相关对象位置。然后，我们使用基于中心的检测来识别与对象位置相关的像素功能的位置，这是图像中总数的一小部分。然后将它们投射并融合在BEV框架中。在Nuscenes数据集上，我们的表现优于仅限激光雷达基线的4.9％地图，同时比其他融合方法融合了100倍。