调制度测量轮廓术的系统标定

Calibration of the Measurement System Based on Modulation Measurement Profilometry

调制度测量轮廓术是一种采用垂直测量方式的三维面形测量方法,可以测量表面有剧烈变化区域的复杂物体。提出了一种基于调制度测量轮廓术测量系统的标定方法,其纵向标定是利用几个相互平行的标定平面建立与CCD像面各像素点对应的测量高度与实际高度之间的映射关系,并利用映射关系确定每一像素点对应的映射关系系数,然后建立映射关系系数查找表,存入测量系统中,完成纵向标定。首先分析了测量系统的误差来源,然后给出了标定方法和标定过程,最后给出了实测结果。结果表明,利用提出的系统标定方法可以有效消除调制度测量轮廓术测量系统误差,显著地提高了系统测量精度。

In modulation measurement profilometry (MMP), the shape of a testing object is directly decoded from the fringe modulation instead of phase value calculated by fringes recorded from the surface of a diffuse object. A calibration procedure of the measurement system is presented based on MMP. Several parallel planes are used to establish the height-mapping between the measured height and the true height of the object. A look-up table of the height-mapping coefficient is established and stored in the measurement system. The measuring results show that the system error is compensated for and one order higher accuracy can be achieved by the presented system calibration method.