脉冲激光测距接收电路与计时方法研究-光学工程专业毕业论文.docxVIP

浙江大学坝}学位论立摘 浙江大学坝}学位论立 摘 要 Y S81391 本论文详细讨论了一种可实现高速激光测距的接收电路和计时电路。实验系 统采用APD作为光电传感器，将激光脉冲信号转变为微弱电流脉冲，经过两级 放大后．信号变为幅度较大的电压脉冲，经过时点鉴别电路分别确定计时起点和 终点后，由计时电路来精确测量两个时问点之间的时间间隔。普通脉冲测距计时 方法，往往需要对飞行时间放大，导致测量速度下降。针对陔问题，基于传递延 时插入法和CPLD的工作原理，对快速测距技术进行了研究，研制了一种能实现 收到回波脉冲后80ns内完成测距，测距精度±O．2m的计时电路，并将该电路集 成于一片可编程逻辑器件中，减小了电路面积和功耗，增强了抗干扰能力。对 15m外的物体，测量时间由目标物的距离决定。该项技术可用于需要对H标物进 行高速扫描的三维激光成像雷达。 关键词： 高速测距可编程逻辑器件传递延时激光测距APD 黔、聊同意～ 纫全文公布 浙江人学坝打学位论文n‘J 浙江人学坝打学位论文 n‘J Abstract +1 1 A type of receiver circuit and timing circuit which can be applied in high·speed laser range—finder is discussed in this papen in the experimental system APD transferred laser pulse to weak electrical current．After two-level amplification we got a voltage pulse that had a enough amplitude to be applied，the timing point was discriminated by the constant-fraction timing discriminator circuit．Timing circuits transferred the pulse flight time to digital signal accurately．Implementing normal time measuring method，night time of pulse laser Was multiplied and measuring speed was de．multiplied．To solve this problem，quick range measurement technology was researched based on the method ofpropagation delay and working principle of CPLD A time measurement circuit with an accuracy of±0．2m was designed and accomplished．It could finish the whole measurement process in 80ns after the bounced pulse was received．This circuit could be integrated in one chip of programmable logic device，SO the area and power consumption was decreased and anti，interference ability was strengthened．If the object was more than 1 5m away，the measuring time of radar was determined by the distance of the objects．The content of this paper can be applied in three—dimensional laser image radar which scans on targets in high—speed． Keyword：high-speed measurement；programmable logic device；propagation delay laser range·finder；APD 2 浙江人学坝I‘学位论文第一章绪论 浙江人学坝I‘学位论文 第一章绪论 §1．1激光测距技术原理介绍 §1．1．1原理概述 一个典型的激光测距系统应具备以下几个单元：激光发射单元，激光接收单 元，距离计算与显示单元，准直与聚焦单元，如图1-1所示。系统工作时，激