调频连续波激光测距具有无盲区、非接触测量和绝对测距等优点,但是由于可调谐激光器光频率调制非线性对其测量精度的影响,限制了调频连续波激光测距在精密测量领域中的应用。针对调频连续波激光测距中测距精度受到激光器光频率调制非线性的影响,提出了双干涉光路调频连续波激光测距方法,利用两个干涉系统得到的干涉条纹数量的比值计算得到被测目标的距离,消除了激光器光频率调制非线性对测距精度的影响,实现了65 μm的测量分辨率和15 μm的重复测量精度。该方法无需对激光的波长进行测量,也无需对激光器进行锁频,系统组成简单,在工业大尺寸测量、空间技术、测绘等领域有着广阔的应用前景。

Frequency Modulated Continuous Wave(FMCW)laser ranging has many advantages such as no measuring blind area, noncontact measuring and absolute distance measurement. However the measuring precision of FMCW laser ranging is limited by the modulation nonlinearity of tunable laser. Hence, this technology is not widely used in the field of precision measurement. The precision of FMCW laser ranging was affected by the nonlinearity of laser frequency modulation. The method of dual interferometry FMCW laser ranging was proposed. The distance of the target was equal to the ratio of the interference fringe of two interference systems. Using the method, the influence caused by the nonlinearity of laser frequency modulation was eliminated. The resolution and repeatability precision of the system was 65 μm and 15 μm respectively. The system has the following advantages. There is no need to measure the wavelength of the laser or lock the frequency of laser. And the structure is simple. This system has a wide application prospect in industrial large scale measurement, space technology, and surveying.