激光3D图像传感器收发合置光学系统设计与实现

发布时间：2018-06-04 14:15

本文选题：激光雷达 + 扩束准直　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：近年来,随着无人机、无人车等环境感知技术的发展,激光3D图像传感技术得到了各国学者高度关注,其高分辨率和高精度是其广泛应用的基础。本文根据激光3D图像传感器实际需求,提出并设计了一种新型收发合置光学系统,以偏振光学隔离开关为核心,将发射光学系统和接收光学系统共口径;引入f-?扫描光学系统,解决了接收系统效率较低的问题;利用ZEMAX软件对发射和接收光学系统进行设计和优化,最终加工完成收发合置光学系统,并通过实验进行验证。论文主要从以下几个方面展开:首先,结合收发分置和收发合置系统的不同特点,分析了两种系统存在的优势和不足,从提高系统共轴度、降低背景噪声角度出发,提出了本文收发合置系统设计;研究了发射光学系统和透镜准直扩束技术,推导了高斯光束的基本特性和透镜变换的基本原理;结合课题设计要求,应用高斯光束透镜变换理论,使用ZEMAX软件设计了一级扩束(预扩束)和二级扩束光学系统,分析研究了两个系统点列图、像差等,最终实现了10mm光斑直径准直输出;其次,基于激光成像雷达直接探测基本理论,分析了激光雷达系统探测过程中,系统回波功率计算方法以及背景光噪声对系统成像质量的影响;研究了传统光隔离开关的设计原理与方法,指出了中心孔洞造成回波信号功率损失的弊端;从薄膜偏振分束棱镜原理出发,有效利用1/2、1/4波片不同偏振特性,设计了一种基于偏振隔离原理的光学隔离开关。同时,完成了光学隔离开关系统搭建,并就如何降低光隔离系统信噪比进行了研究;针对接收光学系统聚焦回波信号特性,分析了APD探测器与接收视场的关系,设计了一套接收光学系统,符合本文设计要求;最后,完成了激光3D图像传感器收发合置光学系统设计,分析了本文设计的合置收发系统在激光成像雷达领域的优势,对整个实验装置进行了装调和实验。完成了偏振隔离系统测试和不同目标成像实验,在均匀材质和复杂目标成像方面得到了很好的探测结果。测试结果表明,本文设计的光学系统符合技术指标要求,杂散光隔离效果较好,近地目标探测精度较高。
[Abstract]:In recent years, with the development of environment sensing technology, such as unmanned aerial vehicle and unmanned vehicle, laser 3D image sensing technology has been paid great attention by scholars all over the world. Its high resolution and high precision are the basis of its wide application. According to the actual demand of laser 3D image sensor, a new transceiver and receiver optical system is proposed and designed in this paper. The problem of low efficiency of receiving system is solved by scanning optical system, and the transmitter and receiver optical system is designed and optimized by ZEMAX software. Finally, the optical system of transceiver and receiver is finished and verified by experiment. Firstly, combining the different characteristics of the transceiver and transceiver system, the advantages and disadvantages of the two systems are analyzed. From the angle of increasing the coaxiality of the system and reducing the background noise, the paper analyzes the advantages and disadvantages of the two systems in order to improve the coaxiality of the system and reduce the background noise. In this paper, the design of the transceiver and transceiver system is presented, the emission optical system and collimation beam expansion technology are studied, the basic characteristics of Gao Si beam and the basic principle of lens transformation are deduced. Based on the theory of Gao Si beam lens transformation and ZEMAX software, the first and second order beam expanding optical systems are designed. The point diagram and aberration of the two systems are analyzed and studied. Finally, the collimation output of 10mm spot diameter is realized. Based on the basic theory of direct detection of laser imaging radar, the calculation method of system echo power and the influence of background light noise on the imaging quality of laser radar system are analyzed. This paper studies the design principle and method of traditional optical isolator, points out the disadvantage of the power loss of echo signal caused by central hole, and, based on the principle of thin-film polarization beam splitting prism, effectively utilizes the different polarization characteristics of 1 / 2 / 1 / 4 wave plate. An optical isolation switch based on polarization isolation principle is designed. At the same time, the optical isolation switch system is built, and how to reduce the SNR of the optical isolation system is studied, and the relationship between the APD detector and the receiving field of view is analyzed according to the characteristics of the focused echo signal of the receiving optical system. A set of receiving optical system is designed, which meets the design requirements of this paper. Finally, the design of laser 3D image sensor transceiver combined optical system is completed, and the advantages of the combined transceiver system in the field of laser imaging radar are analyzed. The installation and experiment of the whole experimental device are carried out. Polarization isolation system test and different target imaging experiments are completed, and good detection results are obtained in the aspect of uniform material and complex target imaging. The test results show that the optical system designed in this paper meets the technical requirements, the stray light isolation effect is better, and the detection accuracy of near-Earth target is higher.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN958.98;TP212

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