基于多周期条纹投影技术的位相逆推法在物体表面形状测量中的应用

Measurement of surface profiles using back-propagation method based on multi-period fringe projection method

提出了一种基于多周期条纹投影技术和位相逆推法的物体表面形状测量法,该方法通过分析干涉条纹的位相分布来测得物体的表面形状。相对于单波长干涉仪、条纹投影法等其他测量方法而言,多周期条纹投影法不仅具有更高的测量精度和更大的测量范围,而且还可以用来测量非连续表面形状。此外,在多周期条纹投影法的基础上,还介绍了一种新的空间位相分析方法:位相逆推法。运用这种方法测量物体表面形状可以极大提高测量的精度和系统的稳定性。数值仿真及实验表明,由位相过零点所得到的测量值精度高于由振幅最大值所得到的测量值精度;当测量范围为毫米级时,基于多周期条纹投影法的位相逆推法的测量精度可以达到微米级。

A measurement method of surface profiles using multi-period fringe projection method is put forward in this pa- per. Interference fringes with different periods are projected on an object surface. Multi-period fringe projection method not only has a higher measurement accuracy but also is suitable for measuring surface profiles with discontinuity. In addition, a new space phase analysis method based on multi-period fringe projection method is proposed： Back-propagation Method. The distance of the baekpropagation provides the position of the object surface. The simulation analysis and experiments show that this method can measure an object surface with discontinuities of several millimeters with high accuracy of several micrometers.