Lidar has become an essential sensor for autonomous driving as it provides
reliable depth estimation. Lidar is also the primary sensor used in building 3D
maps which can be used even in the case of low-cost systems which do not use
Lidar. Computation on Lidar point clouds is intensive as it requires processing
of millions of points per second. Additionally there are many subsequent tasks
such as clustering, detection, tracking and classification which makes
real-time execution challenging. In this paper, we discuss real-time dynamic
object detection algorithms which leverages previously mapped Lidar point
clouds to reduce processing. The prior 3D maps provide a static background
model and we formulate dynamic object detection as a background subtraction
problem. Computation and modeling challenges in the mapping and online
execution pipeline are described. We propose a rejection cascade architecture
to subtract road regions and other 3D regions separately. We implemented an
initial version of our proposed algorithm and evaluated the accuracy on CARLA
simulator.

本研究讨论了一种实时的用于自动驾驶场景的动态物体检测算法，该算法利用了先前建立的 Lidar 点云的静态背景模型，并将动态物体检测视为背景减法问题。研究者提出了拒绝级联结构用于对道路区域和其他 3D 区域分别进行减法操作，该算法基于 CARLA 模拟器进行了初步实现和准确度评估。

使用先验 3D 地图的自动驾驶实时动态物体检测

Real-time Dynamic Object Detection for Autonomous Driving using Prior  3D-Maps

This paper presents a model-free, setting-independent method for online
detection of dynamic objects in 3D lidar data. We explicitly compensate for the
moving-while-scanning operation (motion distortion) of present-day 3D spinning
lidar sensors. Our detection method uses a motion-compensated freespace
querying algorithm and classifies between dynamic (currently moving) and static
(currently stationary) labels at the point level. For a quantitative analysis,
we establish a benchmark with motion-distorted lidar data using CARLA, an
open-source simulator for autonomous driving research. We also provide a
qualitative analysis with real data using a Velodyne HDL-64E in driving
scenarios. Compared to existing 3D lidar methods that are model-free, our
method is unique because of its setting independence and compensation for
pointcloud motion distortion.

本文提出了一种无模型、独立于设置的方法，可以在线检测 3D 激光雷达数据中的动态物体。我们明确地补偿了当前 3D 旋转激光雷达传感器的移动扫描操作（运动畸变）。我们的检测方法使用一种运动补偿的 freespace 查询算法，并在点级别对动态（当前移动）和静态（当前静止）标签进行分类。我们使用 CARLA 建立了基于运动畸变激光雷达数据的基准进行定量分析，CARLA 是用于自动驾驶研究的开源模拟器。我们还使用 Velodyne HDL-64E 在驾驶场景中提供了实际数据的定性分析。与现有的无模型 3D 激光雷达方法相比，我们的方法独特之处在于其设置独立性和对点云运动畸变的补偿。

基于 3D 激光雷达的无地图动态物体在线检测

Mapless Online Detection of Dynamic Objects in 3D Lidar

The assumption of scene rigidity is typical in SLAM algorithms. Such a strong
assumption limits the use of most visual SLAM systems in populated real-world
environments, which are the target of several relevant applications like
service robotics or autonomous vehicles. In this paper we present DynaSLAM, a
visual SLAM system that, building over ORB-SLAM2 [1], adds the capabilities of
dynamic object detection and background inpainting. DynaSLAM is robust in
dynamic scenarios for monocular, stereo and RGB-D configurations. We are
capable of detecting the moving objects either by multi-view geometry, deep
learning or both. Having a static map of the scene allows inpainting the frame
background that has been occluded by such dynamic objects. We evaluate our
system in public monocular, stereo and RGB-D datasets. We study the impact of
several accuracy/speed trade-offs to assess the limits of the proposed
methodology. DynaSLAM outperforms the accuracy of standard visual SLAM
baselines in highly dynamic scenarios. And it also estimates a map of the
static parts of the scene, which is a must for long-term applications in
real-world environments.

本文提出了 DynaSLAM，这是一种基于 ORB-SLAM2 的视觉 SLAM 系统，可以检测动态对象并背景填充，适用于单目，立体和 RGB-D 配置，并在公共数据集中证明了其在高度动态场景中优于标准视觉 SLAM 基线的准确性。