光学位相测量轮廓术的原理研究

Research of principle of phase measurement profilometry

光学位相测量轮廓术(PMP)是一种基于光栅投影和相位测量的光学三维面形测量技术,可有效实现物体表面三维轮廓的自动测量。这种方法采用结构光照明,将正弦光栅图像投影到被测物体表面,用与投影方向成一定角度的CCD摄像机获取受物体表面面形调制的变形光栅像,根据数字相移算法计算出相位分布,由于从相移计算的相位被截断在反三角函数的主值范围[-π,π]内,因而是不连续的,必须通过相位展开恢复出连续相位分布,由相位-高度关系最终求出物体轮廓的三维数据信息。针对该原理进行了阐述,对测量过程中的关键技术进行了分析,并给出了详尽的算法及实验结果。通过MATLAB实验仿真,对条纹图像进行处理和轮廓重构。模拟实验证明,这种测量方法快速高效、分辨率高,且易于实现。

The Phase Measurement Profilometry(PMP) is one of the optical three-dimensional profile measurement techniques based on the grating projection with the structure-light lighting and phase measurement.It can get the three-dimensional profile of the object surface effectively.Because of the cragginess of the three-dimensional surface when sine grating is projected the image of the sine grating is modulated and the modulated image is taken by a CCD camera with an angel compared to projecting direction.After the phase shift measuring method,the phase is gotten.Because the phase is calculated by the phase shift measuring ranges from-π to +π it isn't continuous.The phase unwrapping is necessary to recover the continuous phase about the object shape.With the phase-height relation arithmetic,the three-dimensional surface coordination is obtained.The PMP principle is studied and the detailed algorithm and experimental results are shown. Based on MATLAB language the data processing and reconstructing object are done for the fringe image.Through the simulation experiment this method is proved to be a quick,effective,high precise and easily implemented three-dimensional profile measurement technology.