第21卷第10期 2013年10月
文章编号1004-924X(2013)10-2527-08
光学精密工程
Optics and Precision Engineering
Vol.21No.10
Oct.2013
激光测距系统整形模块和低通滤波模块优化设计
尤政1,2*，杨冉1-2，张高飞1,2，薛旭峰1，叶良琛1.2
（1.清华大学精密仪器系，北京100084；2.清华大学精密测试技术及仪器国家重点实验室，北京100084) 摘要：由于减小相位式激光测距系统的鉴相误差可提高测距精度，本文对鉴相器前置整形模块和后置滤波模块进行了优化设计，以提高鉴相精度。针对整形模块，引人了迟滞比较器，克服了传统开环比较电路在实际噪声条件下存在的多重触发缺陷，解决了鉴相器输出方波高电平宽度不稳定的间题。针对滤波模块，介绍了基于MC4044鉴相芯片的两种典型放大/滤波电路及其缺陷，使用FilterPro软件设计了4阶有源低通滤波器，并说明了它相对于典型设计的优势。实验结果表明：相比于开环比较器，本文设计的迟滞比较器慧免了接地(GND)噪声引起的多重跳变现象，输出方波的上升沿时间由1.66μs下降为108ns；与基于MC4044的两种典型放大/滤波模块设计相比，本文设计的低通滤波电路克服了输出 DC电平值非线性变化的缺陷线性度（R）值由0.9083提高至0.9999)和灵敏度较低的缺陷（转化增益常量提高了 96.5%），而输出DC电平上的干扰信号峰峰值则由50~230mV下降至10~20mV，有效减少了后级的A/D采样误差提高了鉴相精度。
关键调：激光测距系统；萎相精度；退滞比较器；整形模块；放大/滤波模块
中图分类号：TN247：TN713
文献标识码：A
doi:10.3788/OPE.20132110.2527
Optimizationofshapingcircuitandlow-passfilter
inlaserrangingsystem
YOU Zheng-, YANG Ran'-, ZHANG Gao-feil-*, XUE Xu-feng', YE Liang-chen'-(1.DepartmentofPrecisionInstrument，TsinghuaUniversity，Beijing100084,China 2.StateKeyLaboratory ofPrecisionMeasurementTechnologyandInstruments,
TsinghuaUniversity，Beijing100084,China)
+Correspondingauthor,E-mailyz-dpimail.tsinghua.edu.cn
Abstract: As the phase discrimination error of a phase laser ranging system effects its ranging accura cy, this paper optimizes the designs of a preceding stage (shaping circuit) and a subsequent stage(low-pass filter) in the phase detector. For the shaping circuit, a comparator with hysteresis was de signed to avoid the multiple-triggered phenomenon caused by the noise on GND for open loop filters and stabilizes the output of phase detector. For the low-pass filter, two typical amplifier/filter circuits based on MC4044 and their defects were introduced, a 4th-order low-pass filter was designed by using FilterPro, and its advantages were presented. Experimental results indicate that the multiple-trig gered phenomenon is eliminated by using the hysteresis comparator designed, and the rise-time of out
收稿日期：2013-04-10；修订日期：2013-05-13
基金项目：国家863高技术研究发展计划资助项目（No.20124302056）