摘要针对激光雷达系统中高精度时间测量和激光扫描的问题，文章采用TDC（Time-to-Digital-Converter）时间数字转换芯片测时以及转镜扫描激光线的方法进行了单线激光雷达系统设计。通过FPGA设计的脉冲压缩电路，使激光器可以产生15ns脉宽的超窄脉冲。将回波馈入脉冲抑制电路进行预处理，解决了回波中干扰脉冲的问题。基于大量的试验数据，对TDC进行了的误差分析，并利用均值算法提高了TDC的测量精度。另外采用PWM控制无刷电机，解决了电机扫描的同步问题，达到500点/转，误差为10点/转。最后，文章还对系统的各部分及整体的性能进行了试验验证和分析。根据实验的数据和图像得出，激光雷达测量范围能达到10-200m，测量精度为0。15m，帧率为3帧/秒，单帧分辨率为500点/转，可以较好的绘制出场景的一维轮廓。75289

毕业论文关键词激光雷达TDC激光扫描FPGA

Title A Design of Mirror Scanning and Signal Processing Circuit In Lidar System

Abstract To slove the high-precision time measurement and laser scanning problems in Lidar system, the article design a single-line Lidar system by the approach that TDC (Time-to-Digital-Converter) digital conversion chip time measurement and rotating mirror scanning。 By designing a pulse compression circuit in FPGA, the laser can produce ultra-short pulse width of 15ns。 Fed the echo pulse into suppression circuit to solve the problem of interference echo pulse。 Based on a large number of experimental data, made the error analysis about TDC, and use the equal algorithm to improves the TDC's measurement accuracy。 In others, using PWM to control brushless motors to slove the synchronous scanning motor problems and achieve 500 points / revolution, error is 10 points / rev。 Finally, it also verified the performance of every part of the system by experiments and analysis。 According to the experimental data and images obtained, the Lidar can reached with a measurement range of 10-200m, a measurement accuracy of 0。15m, a frame rate of 3 frames / sec, a single frame with a resolution of 500 points / rev, and it can map out a nice scene one-dimensional contour。

Keywords Lidar TDC Mirror scanning FPGA

目 次

1 引言 1

1。1 课题背景及意义 1

1。2 国内外激光雷达研究状况 1

1。3 论文的主要工作 2

2 系统方案设计 4

2。1 激光雷达系统及原理 4

2。2 方案设计 5

3 转镜驱动模块 7

4 信号调理模块 9

4。1 基于 FPGA 的 ns 级窄脉冲发生器 9

4。2 伪回波脉冲抑制电路 12

5 TDC 测量模块 15

5。1 TDC-GP21 简介 15

5。2 TDC 电路 16

5。3 程序框图 17

5。4 主要代码 19

5。5 时间测量方案 20

5。6 数据分析