632 nm FMCW激光雷达在水汽环境中测速与测距的应用  

Application of 632 nm FMCW lidar for simultaneous velocity and distance measurement in humid environment

作　　者：张欣雨 蒋莉莉 宋冉 张治军[1] 李冰冰 苏娟 吴锜 Zhang Xinyu;Jiang Lili;Song Ran;Zhang Zhijun;Li Bingbing;Su Juan;Wu Qi(Institute of Marine Science and Technology,Shandong University,Qingdao 266237,China;Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou 511458,China)

机构地区：[1]山东大学海洋研究院,山东青岛266237 [2]南方海洋科学与工程广东实验室(广州),广东广州511458

出　　处：《红外与激光工程》2024年第3期276-279,共4页Infrared and Laser Engineering

基　　金：南方海洋科学与工程广东省实验室(广州)基金项目(GML2021GD0808)。

摘　　要：在高海况及复杂环境下,面向无人机和无人艇协同精准降落的需求,在水汽环境中同时精确测量彼此的距离和速度对于无人机的安全着艇很有必要。针对这一需求,提出了一种基于可见光波长、调频连续波(FMCW)原理的同时测速和测距的激光雷达系统并开展了实验验证。该系统采用了三角波电流调制信号直接注入调制激光器,利用激光入射到被测目标物上产生的散射信号光与本振光发生干涉产生拍频信号,解调出被测目标物的速度和距离信息。实验结果显示,该技术可以实现距离测量范围10~130 cm,分辨率1.5 cm,最大相对标准偏差1.5%;速度测量范围10~125 cm/s,速度分辨率0.5 cm/s,最大相对标准偏差0.6%。Objective In high sea conditions and complex environments,for achieving safe landing of unmanned aerial vehicles(UAV)on unmanned surface vehicles(USV),it is necessary to accurately measure the distance and speed simultaneously between them and provide real-time feedback to the control system.However,commonly used GPS navigation and vision-based navigation approaches often suffer from insufficient dynamic positioning.These technologies could only measure distance but not the relative speed between UAV and USV.Frequency modulated continuous wave(FMCW)lidar,which could simultaneously measure both velocity and distance,has great potential for application in autonomous landing between UAV and USV during high sea conditions.For different applications,FMCW lidar could utilize different frequency modulation schemes on the optical carrier.Commonly used frequency modulation scheme includes the triangular,the sawtooth,and the sinusoidal waveforms.It is an economical and convenient approach to measure velocity and distance simultaneously using a triangular waveform modulated FMCW lidar.Considering eye safety,FMCW lidar normally deploys lasers with wavelengths longer than 1550 nm.However,the light absorption in the moisture above air/sea surface is too large for the infrared wavelength range.Methods In this paper,the lidar system employing a 632 nm distributed Bragg reflector(DBR)semiconductor laser which operating the water vapor transmission wavelength band and an FMCW technology was proposed and experimentally demonstrated.The symmetric triangular waveform modulation was achieved by directly modulating the laser injection current.The schematic diagram of the system is shown in Fig.1(a),and the experimental setup of the system is shown in Fig.1(b).The modulated laser output,with continuous frequency tuning,was further divided into two beams by a beam splitter(BS).Of which,one beam is used as the reference light,and another beam is used as the detection beam and incident on the measurement target.The detection light,which is

关 键 词：调频连续波 激光雷达 速度测量 距离测量 

分 类 号：TN958.98[电子电信—信号与信息处理]