M8激光雷达回波的非接触式发射率三维分布测量方法  

Non-contact three-dimensional emissivity distribution measurement method of M8 LiDAR echo

作　　者：李荣华[1,2] 邓源 薛豪鹏 周心晨 赵明硕 Li Ronghua;Deng Yuan;Xue Haopeng;Zhou Xinchen;Zhao Mingshuo(Institute of Mechanical Engineering,Dalian Jiaotong University,Dalian 116028,China;Dalian Advanced Robot Perception and Control Technology Innovation Center,Dalian 116028,China)

机构地区：[1]大连交通大学机械工程学院,辽宁大连116028 [2]大连市先进机器人感知与控制技术创新中心,辽宁大连116028

出　　处：《红外与激光工程》2024年第4期157-171,共15页Infrared and Laser Engineering

基　　金：辽宁省教育厅科学研究项目重点项目(LJKZ0475);大连市高层次人才创新支持计划项目(2022RJ03)。

摘　　要：针对目前发射率测量方法只是对某一单一物质进行接触式测量,难以获得复杂目标的发射率三维分布问题,提出一种基于M8激光雷达回波的非接触式发射率三维分布测量方法。首先基于激光雷达传输距离方程分析回波强度特性,通过M8激光雷达对95%标准漫反射板进行扫描,叠加多帧单线点云,得到具有反射光谱特性的雷达强度三维点云像;运用分段多项式模型拟合距离-强度及入射角-强度之间的关系,基于得到的分段多项式模型校正距离和入射角度影响下的回波强度,使不同距离与入射角情况下所测回波强度能够真实地反映目标的反射光谱特性,校正结果显示,标准漫反射板回波强度变异系数分别从0.2676和0.3438降低到了0.0420和0.0412,回波强度一致性分别提高了84.31%和88.02%,使雷达所测得强度值能直接反映目标材料的反射光谱特性,验证了强度校正模型的有效性;最后基于得到的分段多项式校正模型对带有反射率真值贴片的缩比卫星模型雷达强度三维点云像进行强度校正,利用校正后的回波强度的反射光谱特性,计算出目标表面的反射率,运用反射法进一步推导其发射率,得到缩比卫星模型发射率的三维分布,三组卫星模型表面贴片的发射率平均偏差均分别能控制在3.33%、4.84%和4.44%。为目标识别、低空可探测技术等提供技术支持。Objective Emissivity is an important physical quantity to characterize the radiation ability of material surface.It is an important thermal physical parameter and has very important applications in many fields.Emissivity is not the intrinsic property of an object.It is a physical quantity that is difficult to measure accurately.It is related to temperature,wavelength,angle and so on.Its measurement is more complicated.At present,most of the emissivity measurement methods are only contact measurement of a single substance.It is impossible to measure the three-dimensional distribution of emissivity of complex targets.Combined with the characteristics of LiDAR,a non-contact three-dimensional distribution measurement method of emissivity is proposed based on LiDAR echo.Methods Firstly,the echo intensity characteristics are analyzed based on the LiDAR transmission distance equation,the main factors affecting the LiDAR echo intensity are explored,and the target point cloud data with intensity information by line array scanning of 95%reflectivity standard diffuse reflector plate are obtained by line array LiDAR(Fig.4).The stacked multi-frame single line point cloud(Fig.5)and the three-dimensional point cloud image of radar intensity with reflective spectral characteristics is obtained(Fig.8).Secondly,the piecewise polynomial model is used to fit the relationship between distance-intensity and incident angle-intensity(Tab.4).Based on the obtained piecewise polynomial model,the echo intensity under the influence of distance and incident angle is corrected,so that the measured echo intensity under different distance and incident angle can truly reflect the reflection spectrum characteristics of the target,and the validity of the correction model is verified(Fig.15-16).Finally,based on the obtained piecewise polynomial correction model,the intensity correction of the three-dimensional point cloud image of the radar intensity of the scaled satellite model with the reflectivity true value patch is carried out.The reflectivity

关 键 词：激光雷达 发射率 反射率 回波强度 回波强度校正 

分 类 号：TN959.1[电子电信—信号与信息处理]