高精度激光测距雷达系统硬件设计

发布时间：2018-01-14 04:25

本文关键词：高精度激光测距雷达系统硬件设计　出处：《西安电子科技大学》2014年硕士论文　论文类型：学位论文

【摘要】：激光雷达自1961年被提出,在过去的50多年已有长足的发展,其中线性调频连续波激光雷达(LFMCW Ladar)的研究是其中的一个重要方向,广泛运用于环境遥感、大气监测、精密测距等。本课题针对线性调频连续波激光雷达高精度测距,特别是宽带线性调频激光的产生和接收进行了研究,设计了适用于分布反馈(DFB)半导体激光器的线性调频激光产生和接收系统,该研究成果是激光雷达三维成像和合成孔径激光雷达(Synthetic Aperture Ladar,SAL)等技术的基础。本论文完成的工作包括以下几个部分:1.介绍了激光雷达的发展,线性调频激光实现测距的基本原理和本系统基于DFB激光器设计的实现激光线性调频的方法较传统方法的优势和难点。2.设计了一种带光电反馈补偿的DFB激光器驱动模块。包括了系统的时钟设计;FPGA+DAC的预置路驱动电压设计;光电反馈环路,反馈环路低通滤波设计;FPGA+DDS的鉴相器参考频率设计;电压信号转电流信号方案设计。3.设计了线性调频激光信号的相干平衡接收电路,系统的激光信号接收电路有两种方案,一种用于光电反馈补偿路的激光信号接收,另一种用于测距路激光回波信号接收,这两部分的激光功率和差频信号带宽不同,本系统设计了两种不同的光电流信号转电压方案以满足系统高信噪比要求。4.针对系统硬件低噪声要求进行板卡设计和关键信号线处理工作。5.使用MATLAB对光电反馈结果进行深入分析,获取DFB激光器的电流调谐特性,针对性地对驱动信号增加迭代补偿和选择最佳的光电反馈环路参数。
[Abstract]:Lidar has been proposed since 1961. In the past 50 years and more, the research of LFMCW Ladar is one of the important directions. It is widely used in environmental remote sensing, atmospheric monitoring, precision ranging and so on. In this paper, the generation and reception of LFM laser with high precision, especially wideband LFM laser, are studied. A linear frequency modulation (LFM) laser generation and receiving system is designed for distributed feedback DFB semiconductor lasers. The results of this research are lidar 3D imaging and synthetic Aperture Ladar. The work accomplished in this paper includes the following parts: 1. The development of lidar is introduced. The basic principle of realizing ranging by LFM laser and the advantages and difficulties of the method of realizing LFM based on DFB laser. 2. A DF with optoelectronic feedback compensation is designed. B laser drive module, including the clock design of the system; The design of preset drive voltage of FPGA DAC; Optoelectronic feedback loop, feedback loop low pass filter design; The design of the reference frequency of FPGA DDS; Design of voltage signal to current signal. 3. The coherent balanced receiving circuit of LFM laser signal is designed. There are two schemes in the laser signal receiving circuit of the system. One laser signal reception for optoelectronic feedback compensation path and the other for ranging path laser echo signal reception, the laser power and differential frequency signal bandwidth of the two parts are different. This system designed two different photocurrent signal switching schemes to meet the system high signal-to-noise ratio requirements .4.To meet the system hardware low noise requirements board design and key signal line processing work .5. use MAT. The results of optoelectronic feedback are analyzed by LAB. The current tuning characteristics of the DFB laser are obtained, and the iterative compensation of the driving signal and the selection of the optimal optoelectronic feedback loop parameters are proposed.
【学位授予单位】：西安电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN958.98

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