为了精确测量薄板类材料的厚度, 分析了双光路激光三角法测厚原理, 建立了一种单镜头激光三角法厚度测量系统。该系统以半导体激光器为光源, 配以单镜头成像系统、图像采集与数据处理系统。描述了系统的检测原理、检测方法和实验装置, 讨论了激光器光束轴心线与成像透镜光轴夹角与系统分辨率的关系, 并基于最小二乘法拟合得出了光斑距离与被测物厚度的函数关系式, 最后通过标定实验对系统精度进行了实验论证。结果表明, 该系统消除了双光路激光三角法上下测量系统难以同步的问题, 分辨率高, 精度控制在10μm, 良好地满足了工业测量的需求。

In order to measure the thickness of thin plates accurately, the principle of thickness measurement based on double light path laser triangulation was summarized, and a gauging system based upon single lens laser triangulation was established. This system consists of two symmetrically-installed laser devices, a single lens imaging system, an image acquisition system and a data analysis system. Then the principle of measurement, measurement method and experimental facility were described. In the following part, the relation between system distinguishability and intersection angle among laser beam axis line and imaging lens axis was discussed, after that the least square fitting method was selected to get the fitted equation between measure thickness and flare spacing convenient to data analysis. Finally, a calibration experiment was conducted to demonstrate the accuracy. It is found that this system not only eliminate the difficulty of synchronization problem laid in double light path laser triangulation method but also has a high distinguishability, it meets the commercial measurement demand well.