共查询到19条相似文献,搜索用时 78 毫秒
1.
双步相移光栅投影测量轮廓术 总被引:3,自引:0,他引:3
双三步相移算法证明可以较大地减少数字光栅投影测量轮廓术的测量误差,基于理论分析与实验验证,针对常用的四步、五步相移算法,提出了相应的双四步、双五步相移算法。通过两次传统相移算法得到两幅主值相位图,直接融合两幅主值相位图即可获得测量所需的相位信息,与已有的针对两幅展开相位进行相位融合方法相比,此方法实现简单且更加有效。相较于双三步相移算法,双四步和双五步相移算法实现简单且能够极大地减少测量误差,仅需通过投影2倍数目传统相移算法所需的投影光栅,且可保持常用三步、四步及五步相移算法固有的优点。 相似文献
2.
3.
三维形貌测量的扫描相移法研究 总被引:7,自引:6,他引:1
物体三维形貌测量中常用的光切法的主要优点是易于实现扫描测量大型物体表面,缺点是光刀中心位置难以精确确定;相移法的主要优点是可以用较宽的光栅提高测量的灵敏度与准确度,具有测量速度快和较好的抗静态噪声的能力,缺点是当待测范围较大时,采集图像的像差较大,不利于大型物面的测量.将这两种方法有机地结合起来,取长补短,提出了一种扫描相移法.实验结果表明,这个方法不但适用于长形大物面的形貌检测,而且又大大地减少了图像采集系统畸变误差的影响,从而提高了检测准确度. 相似文献
4.
两步相移实现投影栅相位测量轮廓术 总被引:7,自引:2,他引:7
提出一种新的投影栅相位测量方法--两步相移法。该方法只需两幅相移条纹图,因此计算量小,速度快。给出了实验及计算结果,并同四步相移法进行了比较,证明了该方法具有较高的精度。 相似文献
5.
6.
8.
基于彩色光栅投影的快速三维测量方法 总被引:2,自引:1,他引:1
针对条纹投影术提取物体高度信息的问题,提出了一种新的基于彩色光栅投影的三维测量方法。对选取G分量为255,R,B分量各取0或255而组成的青、白、黄、绿四色遵循格雷码原理进行编码,然后将G分量作正弦调制形成投影光栅投向被测物体。提取采集到的光栅变形图中G分量,利用傅里叶变换方法得到其初始相位;同时对采集到图像中的R,B分量作阈值迭代分割而G分量自动赋值为255,综合三分量信息得到条纹颜色信息进而获取条纹的周期信息,从而展开相位。全过程仅需投影一幅彩色光栅图就能完成三维测量,实验结果表明该算法易于实现,在测量实时性和精确性上表现良好。 相似文献
9.
用投影光栅法测量三维物体表面轮廓形状的评述 总被引:1,自引:0,他引:1
从相位的调制与解调角度出发,综述用投影光栅法测量三维物体表面轮廓形状的几种方法:莫尔拓扑法、傅里叶交换轮廓法和相位步进解调法,同时讨论各种方法的优点和不足。 相似文献
10.
11.
12.
13.
In the fringe projection profilometry, the traditional triangle method, such as Fourier-transform profilometry (FTP), is difficult to recover the stepped shape object from the deformed fringe pattern. In order to solve this problem, the neural network is introduced to deal with this kind of fringe patterns and gain the three-dimensional (3D) information of the measured object. By training the network, the relationship between the deformed fringe pattern and the height of the object can be obtained, and thereby the height of the object can be obtained. Furthermore, the object can be reconstructed perfectly without knowing the optical parameters of the experiment system. An obvious merit of this network method is that it can recover the 3D object in a short time and only need one deformed fringe pattern. Computer simulations and experiment validate the feasibility of the method. 相似文献
14.
Quality-guided algorithm is a widely used method in phase unwrapping. This paper shows an accurate quality map based on fringe contrast for 3D shape measurement. Phase-shifted fringe patterns are projected onto an object surface by a programmable liquid crystal projector and recorded by a CCD camera. A wrapped phase map and a fringe contrast map are extracted from the deformed fringe patterns by the phase-shifting technique. Guided by the contrast map, the quality-guided unwrapping algorithm minimizes unwanted shadow and non-uniform surface reflectance effects and is able to retrieve a correct surface profile. Validity of the proposed method is tested on a fish model and a cutting tool specimen. 相似文献
15.
3-D shape measurement based on complementary Gray-code light 总被引:2,自引:0,他引:2
A combination of phase-shift with Gray-code light projection into a three-dimensional (3-D) measurement system has been exploited to digitalize 3-D shape information of a tested object, even with a discontinuous surface. Unfortunately, the phase unwrapping will fall into an error, when an improper value of Gray coding is caused by mistake at the partial boundary of two adjacent binary words. To this end, a new complementary Gray-code method is proposed in this paper as well as the corresponding phase-unwrapping method. This problem of phase unwrapping could be cleverly solved by projecting an additional Gray-code pattern to extend this code and using the different and complementary boundary locations of the traditional and additional codes. The results of computer simulation and experiment confirm that this proposed method based on complementary Gray-code can reliably reconstruct the nature phase distribution of the tested object with only one extra fringe pattern. 相似文献
16.
17.
18.
数字投影系统在三维轮廓术中的应用 总被引:12,自引:4,他引:12
提出了一种测量三维形貌的新型系统 ,并对该系统的特点进行了分析。通过本实验系统与传统实验系统的比较 ,指出了本系统的优点。运用本实验系统 ,采用四步相移法测量的实验步骤 ,提出了一种新的简易而有效的解包络算法。给出了运用本方法测量人头像和标准斜面的结果。通过对测量结果的分析 ,对本实验系统进行了误差因素分析。结果表明 ,该系统易于实现 ,且具有很高的测量精度 ,有广泛的实用价值 相似文献