提出了一种采用频域滤波优化条纹来提高数字相位测量轮廓术(PMP)的测量精度的方法。由于数字投影仪和CCD的数字化特征,CCD获取的正弦条纹会出现多次谐波。而相位测量轮廓术的某些算法对高次谐波敏感使得测量精度低。通过设计滤波器对条纹在频域内进行滤波,对条纹的正弦性进行优化,减弱高次谐波对算法的影响,可以提高系统的测量精度。实验证明,所提出的方法将系统的测量精度提高了3倍,滤波操作完全由计算机自动完成。

A method is presented for improving measuring accuracy of digital phase measuring profilometry(PMP) by frequency filtering. Due to the digitalization characteristics of the digital light projector and CCD,the fringes captured by CCD consist of many harmonic generations. Many algorithms based on PMP are sensitive to the higher harmonic generations,which reduces the measurement accuracy of PMP system. We filter the fringes in frequency domain by designing filters in order to optimize the sine fringes,degrade the effect brought in by higher harmonic generations,so the measuring accuracy of the system is improved. Experiments show the proposed method can improve the measuring accuracy by 3 times,and the filtering operation is accomplished all by computer.