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摘要对回波信号的处理是激光雷达系统工作的核心部分，时刻鉴别直接影响着脉冲激光测距的精度。论文在阐述了激光雷达基本原理的基础上，通过计算机仿真和实验分析，得出了前沿时刻鉴别、峰值鉴别、高通容阻时刻鉴别以及恒比定时时刻鉴别的测距统计分布和测距精度。根据结果，分析了每种时刻鉴别方法的特点以及各方法的测距方差与克拉美罗界的关系。前沿鉴别适用于脉冲较窄的激光，不能解决回波信号脉冲波形和幅值变化造成的漂移误差；峰值鉴别、高通容阻时刻鉴别和恒比定时时刻鉴别可避免因回波信号幅值变化引起的误差，但峰值鉴别可能需对多个峰值进行筛选，高通容阻时刻鉴别无法解决回波信号脉冲极大值附近的斜率带来的误差问题，回波波形的改变会对恒比定时时刻鉴别的测量误差造成大的影响。因此，需要根据具体的测量环境选择合适的方法。43103
毕业论文关键词 激光雷达 脉冲激光测距 时刻鉴别 仿真 实验
毕业设计说明书外文摘要
Title Research on the Method of Pulse Ranging Time Discriminatoin in Digital Full Waveform Laser Radar
Abstract
Echo signal processing is the key part of the work of the ladar system,and the precision of the pulse laser ranging is directly influenced by the timing discrimination.Based on describing the basic principles of ladar,through the computer simulation and experimental analysis,the ranging statistics and ranging precision of the leading edge timing discrimination,peak discrimination,the high pass capacitor and resistor timing discrimination and the constant fraction timing discrimination(CFD) are obtained. According to the results,the characterristics of the respective timing discrimination method and the relationship between the ranging variance of each method and the Cramer-Rao Bound are analyzed.The leading edge discrimination is suitable for the laser with narrow pulse,but it can’t solve the drift error caused by the change of the waveform and amplitude of the echo signal.Peak discrimination, the high pass capacitor and resistor discrimination and CFD can avoid the error caused by the amplitude change of the echo signal.However, peak discrimination may need to select multiple peaks; the high pass capacitor and resistor discrimination can’t solve the error problem caused by the slop near the echo signal maxima;the change of echo waveform will cause great influence on the measurement error of constant fraction timing discrimination.Therefore,we need to select appropriate method according to the specific measurement environment.
Keywords ladar, pulse laser ranging, timing discrimination, simulation， experiment
目 录
摘要 Ⅰ
Abstract Ⅱ
1 绪论 1
1.1 研究背景及意义 1
1.2 国内外研究状况 1
1.3 课题主要研究内容 3
2 激光雷达的基本结构与工作原理 4
2.1 激光雷达的基本结构 4
2.2 激光雷达脉冲测距的工作原理5
2.3 激光雷达脉冲测距中常用的时间鉴别方法6
2.3.1 前沿时刻鉴别法 6
2.3.2 峰值鉴别法 7
2.3.3 高通容阻时刻鉴别法 8
2.3.4 恒比定时时刻鉴别法 8
3 以数字化仿真波形为基础的时刻鉴别方法研究 10
3.1数字化仿真波形获取方法 10
3.2基于不同时刻鉴别方法的测距数据统计分布 13
3.3不同时刻鉴别方法下测距精度的比较和分析 17
3.3.1 克拉美罗下界 17