Zhang H, Lalor M J, Burton D R
Coherent and Electro-Optics Research Group, School of Engineering, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, United Kingdom.
Appl Opt. 1999 Jun 1;38(16):3534-41. doi: 10.1364/ao.38.003534.
A spatiotemporal phase-unwrapping method is presented that combines the dynamic fringe-projection method and the phase-shifting technique and extends the phase-unwrapping method, which measures two phase maps at different sensitivities. The most important feature of the method is that it makes possible the automatic three-dimensional shape measurement of discontinuous objects with large dynamic range limits and high precision because the effective wavelength of the fringe-projection profilometry can be continuously varied over several orders of magnitude by rotation of the projection grating in its own plane. Only one grating and several steps of rotating the grating are required; therefore the method is inherently simple, fast, and robust. In the experiment, choosing the rotation angle was crucial for optimizing the measurement speed and the measurement accuracy. A criterion is presented for the choice of the minimum number of rotational steps for a given accuracy. The experimental results demonstrate the validity of the proposed method.
提出了一种时空相位展开方法，该方法结合了动态条纹投影法和相移技术，扩展了相位展开方法，该方法在不同灵敏度下测量两幅相位图。该方法最重要的特点是，由于条纹投影轮廓术的有效波长可以通过投影光栅在其自身平面内的旋转在几个数量级上连续变化，因此可以对具有大动态范围限制和高精度的不连续物体进行自动三维形状测量。只需要一个光栅和几步光栅旋转；因此，该方法本质上简单、快速且稳健。在实验中，选择旋转角度对于优化测量速度和测量精度至关重要。给出了在给定精度下选择最小旋转步数的标准。实验结果证明了该方法的有效性。
