摘 要：随着计算机技术的发展，结合计算机仿真技术的物体三维轮廓测量得到广泛应用。傅里叶变换轮廓术是测量三维物体重要方法之一，具有快速测量的等优点，但其单一的调制频率无法满足在测量复杂物体时的解相精度要求； 相移方法可以有效抑制零频含有高度信息的基频分量的干扰，但必须由两个具有 相移的光栅条纹图分别投影到被测物体表面，不利于实现快速测量。针对以上问题，本文提出一种在投影之前对光栅进行预处理，将三帧具有 相移的R、G、B单色光栅条纹图调制成一幅彩色光栅图像，投影到被测物体表面，再用彩色CCD采集变形的光栅图像，接着将变形光栅分离成的三幅单色条纹图，利用三步相移算法将含有高度信息的相位分布计算出来，最后利用高度映射公式算出物体三维面形。该方法兼顾了测量范围和解相精度又只需单帧条纹图，避免了严格的相移条件，通过计算机仿真验证，符合计算机软件技术研发的高效性要求，达到快速测量的目的。95001

毕业论文关键词：  三维测量，光栅投影，复合光栅，三步相移算法

Abstract：Along with the rapid development of the technology of computer, the 3D profile measurement of object, combined with computer simulation technology is highly applied。  phase shifting technique is one of the important methods to obtain the information of the object based on Fourier transform profilometry for its great strengths such as fast date acquisition, no damage。 However, the single modulation frequency can not meet the requirement of phase unwrapping accuracy when measuring complex objects。  phase shifting technique can effectively suppress the interference of the zero component on fundamental frequency component which contains altitude information。 But this method need project two grating fringe patterns with  phase shift onto the surface of measured object, which influences the real-time and fast application 。 To measure objects quickly and correctly, a three dimensional measurement, which modulates three R、G、B monochrome gratings with a fixed   phase shift into a color composite grating before the projection, is proposed in this paper。 Then this  composite color grating is projected onto the discontinuous object and the deformed fringe pattern is recorded by a color charge coupled device (CCD) camera。 The captured deformed color fringe is separated into three monochrome gratings。 Next, the phase distribution containing altitude information is calculated by the three step phase shifting algorithm。 Finally, Three-dimensional shape information of the measured object is decoded according to the height mapping formula。 This method ,which only needs a single fringe pattern, takes both the measuring range and the phase demodulation precision into consideration and meets the requirements of the high efficiency of the research as well as the development of computer software technology in order to achieve the purpose of  rapid measurement。 

Keywords：grating projection, three dimensional measurement, composite grating, three-step phase-shifting algorithm

目   录   

1 引言2

1。1 光学三维测量的研究背景2

1。2 光学三维测量的方法2

1。3 光栅投影三维测量的国内外发展现状2

1。4 复合光栅投影法的研究动态3

2 测量原理4

2。1 光栅投影法基本原理4

2。2 相移法基本原理6