一种基于重叠因子的同轴警戒激光雷达动态范围压缩方法  

A dynamic range compression method for coaxial warning LiDAR based on overlap factor

作　　者：刘敬[1,2,3] 金伟其 阙开良[2] Liu Jing;Jin Weiqi;Que Kailiang(MOE Key Laboratory of Photoelectric Imaging Technology and System,Beijing Institute of Technology,Beijing 100081,China;Baoding Galaxy Electronic Technology Co.,Ltd.,Baoding 071025,China;College of Electronic and Information Engineering,Hebei University,Baoding 071000,China)

机构地区：[1]北京理工大学光电成像技术与系统教育部重点实验室,北京100081 [2]河北省保定市天河电子技术有限公司,河北保定071025 [3]河北大学电子信息工程学院,河北保定071000

出　　处：《红外与激光工程》2023年第10期117-126,共10页Infrared and Laser Engineering

基　　金：中央高校基本科研业务费专项资金项目(2021CX02058);河北大学高层次人才科研启动项目(521000981120)。

摘　　要：针对警戒激光雷达近场信号过饱和与雨、雾等天气形成的近距离虚假信号造成“虚警”或“漏警”的问题,研究了一种基于重叠因子的同轴警戒激光雷达动态范围压缩方法。由经典激光雷达方程以及同轴遮挡和激光光斑能量分布的概率密度函数,建立了激光雷达方程修正模型;针对商用警戒激光雷达进行了响应曲线测试,并与基于激光雷达方程修正模型仿真的响应曲线进行对比分析,验证模型的有效性;仿真分析了发射透镜半径、光阑半径、激光发散角、接收透镜焦距四个参数对响应曲线的影响,结果表明:光阑半径是影响响应曲线的最主要因素,增大光阑半径可以显著压缩近场信号,进而压缩响应曲线的动态范围。论文建立的激光雷达方程修正模型对激光雷达初始设计具有重要指导意义及广泛的应用前景。Objective The warning LiDAR used in industries such as autonomous driving and smart mining obtains target distance and alerts by threshold detection of echo.When an warning LiDAR works in an adverse environment(fog,dust,etc.),the emitted laser pulse will be scattered when it hits water drops or dust.Backscattered light will form backscattering echo,and forwardscattered light will be reflected when encountering an object to form a target reflection echo.Backscattering echo will interfere with the detection of target reflection echo.Therefore,backscattering echo compression is essential for the warning LiDAR.Methods For the detection of surface targets,the intensity of the LiDAR echo is inversely proportional to the square of the distance,resulting in the intensity of the near-distance echo being several orders of magnitude greater than the intensity of the far-distance echo.Because the optical path of the backscattering echo is shorter than that of the target reflection,the backscattering echo is in front of the target reflection echo.The optical and mechanical structure of the LiDAR transmission module obstructing the receiving field of view can affect the near-distance responsibility,resulting in the echo strength not monotonically decreasing with distance,but first increasing and then decreasing with distance.By reverse utilizing this attribute,we can model the LiDAR echo based on the optical and mechanical structural parameters(overlap factor)to achieve near-distance echo compression,thereby compressing backscattering echo in adverse environments(fog,dust,etc.)without affecting target reflection echo,and thus reducing false alarm rate.A dynamic range compression method for coaxial warning LiDAR based on overlap factor is proposed utilizing the influence of coaxial occlusion and nonuniformity of laser spot energy distribution on overlap factor(Fig.4-7).Results and Discussions LiDAR with parameters in Tab.1 is used to measure response curve and parameters in Tab.1 is used to get simulated response curve.Table 2

关 键 词：激光雷达 响应曲线 动态范围压缩 基模高斯激光 

分 类 号：O439[机械工程—光学工程]