Phase measuring deflectometry (PMD) is a superior technique to obtain three-dimensional (3D) shape information of specular surfaces because of its advantages of large dynamic range, noncontact operation, full-field measurement, fast acquisition, high precision, and automatic data processing. We review the recent advances on PMD. The basic principle of PMD is introduced following several PMD methods based on fringe reflection. First, a direct PMD (DPMD) method is reviewed for measuring 3D shape of specular objects having discontinuous surfaces. The DPMD method builds the direct relationship between phase and depth data, without gradient integration procedure. Second, an infrared PMD (IR-PMD) method is reviewed to measure specular objects. Because IR light is used as a light source, the IR-PMD method is insensitive to the effect of ambient light on the measured results and has high measurement accuracy. Third, a proposed method is reviewed to measure the 3D shape of partial reflective objects having discontinuous surfaces by combining fringe projection profilometry and DPMD. Then, the effects of error sources that mainly include phase error and geometric calibration error on the measurement results are analyzed, and the performance of the 3D shape measurement system is also evaluated. Finally, the future research directions of PMD are discussed.

中文翻译：

---

用于获得镜面表面3D形状的相位测量折光仪：最新技术回顾

相位测量偏折法（PMD）是一种获得镜面曲面的三维（3D）形状信息的高级技术，因为它具有动态范围大，非接触式操作，全场测量，快速采集，高精度和自动数据处理的优点。我们回顾了PMD的最新进展。介绍了基于条纹反射的几种PMD方法，介绍了PMD的基本原理。首先，回顾了直接PMD（DPMD）方法以测量具有不连续表面的镜面对象的3D形状。DPMD方法无需梯度积分过程即可建立相位和深度数据之间的直接关系。其次，回顾了红外PMD（IR-PMD）方法来测量镜面物体。由于使用红外光作为光源，IR-PMD方法对环境光对测量结果的影响不敏感，并且具有很高的测量精度。第三，回顾了一种提出的方​​法，通过结合条纹投影轮廓测量法和DPMD测量具有不连续表面的部分反射物体的3D形状。然后，分析主要包括相位误差和几何校准误差的误差源对测量结果的影响，并评估3D形状测量系统的性能。最后，讨论了PMD的未来研究方向。分析了主要包括相位误差和几何校准误差的误差源对测量结果的影响，并评估了3D形状测量系统的性能。最后，讨论了PMD的未来研究方向。分析了主要包括相位误差和几何校准误差的误差源对测量结果的影响，并评估了3D形状测量系统的性能。最后，讨论了PMD的未来研究方向。