摘要
为了提高激光测距的精度与稳定性,通过改良传统相位激光测距仪,设计了新型正交调制降频与最小二乘法解相位的相位式激光测距仪。使用反射镜实现内外测距光路,通过正交调制技术对发射激光进行幅度调制,接收模块接收到的回波信号经过混频器后再经过低通滤波器将回波信号降频,降低解相难度并提升解相精度。改用分时测量得到距离相位从而消除二次混频方法所产生的附加相移,分别对内外光路低频回波信号采样进行模数转换后使用最小二乘法求解相位。采用多频率调制测量兼顾激光测距范围与测量精度,最后通过超定方程解模糊算法求解多频测距的待测距离。在国家标准基线上进行样机测试,实验结果表明,在60m量程内正交调制激光测距仪的测量平均误差控制在1.5mm以内,测距量程内标准差保持在0.9mm以内。
A novel laser range finder method based on the quadrature modem and least square method was investigated to improve the accuracy and reliability of traditional portable phase laser range find- ers. A reflector was employed for inner and outer optical paths. After amplitude modulation of laser intensity by the quadrature modulation method, the echo signal was mixed with modulation signal and passed through a low-pass filter to reduce the frequency, thus simplifying phase detection and impro- ving solution accuracies. The inner and outer phase shifts were used to eliminate the additional phase shift lead by the secondary mixing. The low frequency echo signal from the inner and outer optical path were sampled for analog to digital conversion respectively, then the phase was solved base on the least square method. Multi-frequency measurement was adopted to maintain the laser ranging range and measurement accuracy. Finally, the measured distance was obtained by solving the laser ranging am- biguity by overdetermined linear equation. The proposed range finder was experimented on the national stand- ard baseline. The results show that the prototypes of those rangers exhibit an average measurement error less than 1.5 mm and an standard deviation less than O. 9 mm in the range of 0-60 m.
出处
《光学精密工程》
EI
CAS
CSCD
北大核心
2017年第8期1979-1986,共8页
Optics and Precision Engineering
基金
国家重点基础研究发展计划资助项目(No.2011CB707904)
关键词
激光测距
正交调制
最小二乘法
超定方程
解模糊
laser ranging
quadrature modem
least square method
overdetermined equation
ambi-guity resolution
作者简介
许贤泽（1967-），男，湖北京山人，博士。教授，博士生导师，1989年于合肥工业大学获得学士学位，1992年和2002年于武汉理工大学分别获得硕士和博士学位，主要从事精密仪器与超声医学图像处理领域的研究。E-mail：XXZ@whu．edu．cn
翁名杰（1992-），男，福建福清人，硕士研究生，2015年于武汉理工大学获得学士学位，主要研究方向为精密仪器与智能控制。E-mail：723809366@qq．com
徐逢秋（1990-），男，江西丰城人，博士，讲师，2011年和2016年于武汉大学分别获得学士和博士学位，主要从事精密仪器，超声医学图像处理等方面的研究。E-mail：hncxu@whu．edu．cn
