利用快速傅立叶变换分析PMP相移机构的相移误差

The Analysis of the Phase-Shift Error of the PMP Phase-Shift Device Using FFT Method

对PMP系统中标准N步相移误差进行研究,通过利用快速傅立叶变换的全场快速分析的特点,在频域范围内进行滤波和傅立叶逆变换后,迅速找到每步相移的误差值曲面,然后经过曲面拟合找出每次相移与标准相移之间的较为准确的误差值均值,为后续的PMP相位展开提供了一个用以补偿相移误差的修正值,从而提高PMP测量的准确度。

The research on the phase-shift error of the PMP device＇s standard N-step was carried out in this paper, and every step phase-shift error surface can be obtained by FFT, filtering in the frequency field and the inverse-FFT. And then, the accurate error between every step and standard step was found by the curved surface fitting. Accordingly, it can supply a reference value to compensate the phase-shift error in the later PMP phase-unwrapping, whereby improving the PMP measuring accuracy.