摘要
调频连续波激光测距方法可以实现高精度的大尺寸绝对距离测量,且测量过程无需合作目标,在大空间坐标精密测量领域有很高的研究价值.而如何提高测量分辨率和实用化一直是近年来调频连续波激光绝对测距研究的热点.本文研究了调频连续波激光测距的原理,基于双光路调频连续波激光测距系统,提出了通过信号拼接提高测量分辨率的信号处理优化方案,该方案可以提高测距分辨率,且可以降低对激光器的性能要求;提出了可实现高速测量的简易测量方法.设计加工了双光路光纤调频连续波激光测距系统,利用该系统进行了测距分辨率及测距误差标定实验,实验结果表明:优化方案可以有效地提高测量分辨率和测量效率,在26 m测量范围内,测距分辨率达到了50μm,测距误差不超过100μm;快速测量方案有较高实用价值.
Frequency modulated continuous wave（FMCW） laser ranging is one of the most interesting techniques for precision distance metrology.It is a promising candidate for absolute distance measurement at large standoff distances（10 to 100m） with high precision and accuracy,and no cooperation target is needed during the measuring process.How to improve the measurement resolution in practice has been the research focus of the FMCW laser ranging in recent years.FMCW laser ranging system uses the method which may convert the measurement of flight time to the frequency measurement,while the ranging resolution can be determined by the tuning range of the optical frequency sweep in theory.The main impact-factor that reduces the resolution is the tuning nonlinearity of the laser source,which may cause an amount of error points within the sampling signal.So a dual-interferometric FMCW laser ranging system is adopted in this paper.Compared to the traditional Michelson scheme,an assistant interferometer is added.The assistant interferometer has an all-fiber optical Mach-Zehnder configuration,and the delay distance is at least 2 times longer than OPD（optical path difference） of the main interferometer.Because it provides the reference length,the length of the fiber must remain unchanged.The interference signal is obtained on the photodetector.At the time points of every peak and bottom of the auxiliary interferometer signal,the beating signal from the main interferometer is re-sampled.The original signal is not the equal time intervals,while the re-sampled signal is the equal optical frequency intervals.Based on the property of the re-sampled signal,a method by splicing the re-sampled signal to optimize the signal processing is proposed,by which the tuning range of the laser source limitation can be broken and high precision can be easily obtained.Also,a simple high-speed measuring method is proposed.Based on all the above principles,the two-fiber optical frequency-modulated continuous wave laser ranging system is design
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2015年第23期35-41,共7页
Acta Physica Sinica
基金
国家自然科学基金(批准号:51327006
51275350)
高等学校博士学科点专项科研基金(批准编号:20120032130002)资助的课题~~
关键词
连续激光调频
绝对测距
干涉测量
FMCW
the absolute distance measurement
interferometry
