金属表面轮廓的线结构光测量研究

Measurement of metal surface profile using line structured light

为研究线结构光法在测量金属表面轮廓时所能达到的测量精度和影响因素,首先对线结构光测量仪的性能进行了分析,然后完成了对金属样块表面轮廓的测量实验,并与同属光三角测量原理的光切法进行了对比。结果表明:线结构光测量仪的线性度、分辨率和重复测量精度都比较高,能实现微米级的位移测量。但受激光散斑噪声和金属表面反光等因素的影响,该方法的轮廓测量精度大于10μm。而光切法的轮廓测量精度接近微米级。因此,结合光切法的优点,在保证测量范围和工作距离的前提下,设计能投射无散斑高质量光条的光路结构,可以进一步提高线结构光法的轮廓测量精度。

To study the measurement accuracy and influence factors of line structured light method in measuring the metal surface profile,the performance of line structured light measuring instrument was analyzed first,then profile measurement experiments using metal specimens were conducted and compared with light-section method which belongs to the same principle of optical triangulation.The results indicated that the line structured light measuring instrument had high linearity,resolution and repeatable measuring accuracy,and could realize displacement measuring at micron level.However,due to the influence of laser speckle noise and metal surface reflection,the profile measurement accuracy of this method was greater than 10μm.The profile measurement accuracy of light-section method was close to micron level.Therefore,combining the advantages of light-section method,under the premise of ensuring enough measuring range and working distance,the design of light path structure that can project non-speckle highquality light strip can further improve profile measurement accuracy of line structured light method.