三维形貌检测中自动参考栅技术的改进

Improvement for the automatic reference method of 3-D surface measurement

通过对形貌检测中理论参考面相位分布规律的分析 ,对三维形貌轮廓术中参考面相位自动生成技术进行了研究。利用采集的待测物体栅线图样中未变形区域对应相位信息 ,通过最小二乘迭代法数据拟合 ,获得理想参考面相位分布参数 ,也就是获得理想参考面上的相位分布。由于不需另外采集实物参考面变形光栅图像 ,不仅减少了实物参考面的采集步骤 ,而且不需要对实物参考面相位进行求解 ,这样就可以真正实现只采集一幅图像解调形貌 ,从而提高测试速度 ,同时还可避免由于采用实物参考面而存在的误差 ,使得求解兼有理想参考面方法与实物参考面方法的优点。利用改进的方法对塑胶小熊猫面具进行了实际测量 。

A new method of obtaining automatically phase on the reference plane is proposed based on the theoretical analysis on idealized reference plane. The ideal phase distribution of the reference plane can be achieved according to the parameters which are computed by the least square interactive fitting of the corresponding phase of captured specimen grating. The procedures of capturing objective reference and demodulating of its phase are omitted because it is not necessary to gather the additional objective reference. The advantages of both theoretical reference and objective reference can be combined in the method because the influence of the objective reference is eliminated. The speed is quickened because of only capturing one frame deformed grating. The profile of plastic bear mask is measured by the method. The measurement result is shown.