傅里叶变换轮廓术中零频对三维面形测量精度的影响

The Influence on the 3-D Profile Measurement Accuracy of the Object by Zero Frequency in FTP

傅里叶变换轮廓术是一种测量物体表面三维形貌的技术,它只需要一幅干涉图即可对整个范围进行分析,其测量系统简约,分辨率高,计算机处理数据快,计算精度高,且具有很强的非接触测量优势,从而得到广泛的应用.本文采用了双色正弦条纹投影技术来消除零频的影响,该方法同传统的π相移方法相比,不需要相移装置,测量系统简单,能真正实现高速测量.本文从理论和实验上阐述了零频对三维面形测量精度的影响.

In This paper,an optical profilometric technique was investigated,Fourier Transform Profilometry.It has the advantage that only one fringe pattern is needed to full-field acquisition,system simple,high-resolution,fast processing,high calculation accuracy,and suitable for non-contact operation,it made this technology be widely used.Bi-color fringe pattern is projected onto the object and the deformed color fringe pattern is captured by color digital camera.Two separate fringe patterns with phase difference are extracted and used to eliminate the zero component.The method not only can eliminate zero frequency overlapping fundamental component using only one fringe pattern,but also simplify the experimental setup because of no need of phase-shift device.The influence on the 3-d profile measurement accuracy of the object were discussed by zero frequency in theoretical and practical method.