利用信号拼接提高调频连续波激光测距系统的分辨力

提出了一种对等频率间隔的采样信号进行拼接来提高调频连续波激光测距系统的测距分辨力的方法。研究了调频连续波激光测距的原理,设计搭建了基于一种双干涉系统的光纤调频连续波激光测距系统。利用辅助干涉系统产生的时钟信号对测量干涉系统的信号进行等光频间隔的采样,然后对采样信号进行拼接。使用LabVIEW设计了信号错误检测处理、采样和拼接的信号处理系统。利用该测距系统进行了实验验证,结果显示,将等光频间隔的采样信号进行拼接的方法可以突破激光器扫描范围的限制,减少光源非线性的影响,从而提高系统的测距分辨力。得到结果表明,在测量距离为8.7m时,该系统的测距分辨力可达70μm,30组测量结果的重复性标准差为35μm。

Improvement of resolution of frequency modulated continuous wave laser ranging system by signal splicing

A new method to improve the measuring resolution of a Frequency Modulated Continuous Wave (FMCW) laser ranging system was presented by splicing the sampling signals at an equal frequency interval. The principle of FMCW laser ranging was explored and a fiber FMCW laser ranging system based on dual-interferometric systems was built. In which, the auxiliary interferometric system was used to generate time clock pulses to sample the measured signals at equally spaced optical frequencies and then to splice the sampling signals. By using LabVIEW graphical programming software, a signal processing system was design to detect signal errors, sample and splice signals. The experiments on the ranging system proposed were performed. The results show that the proposed method for sampling and splicing measured signals at equally spaced optical frequencies breaks though the laser scanning limitation and reduces the effect of tuning nonlinearity of the laser source, so it improves the ranging resolution. In the experiments, it offers the range resolution of 70 μm at 8.7 m and the standard deviation of 30 group results is 35 μm.