采用传统的傅里叶变换轮廓术(FTP), 必须保证投影装置出射光瞳和成像装置入射光瞳的连线与参考面平行, 并且它们的光轴应在同一平面上, 才能得到较为准确的测量结果。改进了傅里叶变换轮廓术测量装置, 从理论上证明了双瞳连线不平行参考面, 且双光轴也不共面时的测量原理, 推导出了新的、适用范围更广泛的相位-高度映射算法, 使实验系统的搭建变得比较容易, 投影装置和成像装置的摆放位置可以随意移动以方便获取全场条纹。所提出的方法为在难以实现双瞳与参考面平行或难以使双轴共面的特殊环境下提供了获得可靠测量结果的途径, 并且传统的傅里叶变换轮廓术测量系统是所提出系统结构的一个特例。计算机模拟及实验均证实了该方法的有效性。

In order to obtain the correct height reconstruction of a measured object through the traditional Fourier transform profilometry (FTP), the connecting-line between the exit pupil of the projecting lens and the entrance pupil of the imaging lens must be horizontal and set to parallel to the reference plane. Here an improved optical geometry of FTP is discussed, and a strict theoretical analysis about an improved phase-height mapping formula based on a new description of a reference fringe and a deformed fringe in FTP is proposed in this paper when the location of the exit pupil of the projecting lens and that of the entrance pupil of the imaging lens do not meet the conditions. Employing the new theory, it is easier to obtain the full-field fringe through adjusting either the location of the projector or imaging device. Especially, in some cases, i.e., the connecting-line of the two pupils cannot be set parallel to the reference plane and the requived conditions that the projecting and imaging axes must be horizontal cannot be met, the new method offers a flexible way to obtain the reliable height distribution of a measured object. Computer simulations and experiments have proved its correctness.