【作者】 罗春红；

【导师】 王文格；

【作者基本信息】 湖南大学 ， 机械电子工程， 2004， 硕士

【摘要】 随着科学技术和工业的发展，三维测量技术在自动化生产、质量控制、机器人视觉、反求工程、CAD／CAM以及生物医学工程等方面的应用日益重要。传统的接触式测量技术存在测量力、测量时间长、需进行测头半径的补偿、不能测量弹性或脆性材料等局限性，因而不能满足现代工业发展的需要。光学非接触式三维测量技术克服了上述缺陷，成为近年来三维测量技术研究的热点。 本文描述了一种新型的非接触式的光学投影三维测量系统。该系统采用了数字相移条纹投影技术，测量具有非接触、全场、精度较高及快速等优点。在传统相移系统中，条纹图通常都是通过物理光栅得到，并且条纹图的相位移动也是由光栅的移动来实现。而本系统采用数字条纹投影系统，用计算机产生高亮度与高对比度的标准正弦投影条纹，从而提高系统的分辨率与测量精度，并用软件控制精确地实现相位移动，避免了传统相移系统带来的各种误差。 文中阐述了基于数字相移条纹投影技术的三维测量方法的基本原理。针对传统结构系统标定法中存在的问题，对传统结构进行了改进，标定中去掉了传统结构的平行度的约束要求，有较高的可操作性，提高了系统的测量精度。对摄像机镜头的非线性畸变的机理进行了研究，提出了一种提高条纹投影测量精度的摄像机镜头畸变系数的优化方法，从对参考平面的测量出发，考察其上的若干测量点，找到其变形与摄像机镜头畸变系数的函数关系，进而确定摄像机镜头畸变系数，并给出了由于镜头畸变给测量带来的误差的补偿方法。更多还原

【Abstract】 With the development of science and technology and industry, 3D measurement techniques are increasingly important in production for automation, quality control machine vision, reversal engineering, CAD/CAM and biomedical engineering, etc. Traditional contact measurement techniques have lots of flaws, such as measurement force companying with measurement process, being time-consuming, needing compensation for radius of the test head, and being unable to measure elastic or fragile material, and so on. Therefore, it can’t meet demands of the development of modern industry. Optical non-contact 3D measurement techniques have become the focus of research of 3D measurement techniques in recent years because of overcoming the defects above-mentioned.A kind of new-type non-contact 3D measurement system is described in this paper. The system adopts digital phase-shifting and fringe projection techniques and its measurement has advantages of non-contact, the whole field, higher precision, and quite high speed. In traditional phase-shifting systems, the fringe patterns are usually abtained through the physical grating, and it is realized by the movement of the grating that phase-shifting of the fringe patterns is moved. However, the system described in this paper adopts the digital fringe projection system to produce the standard sinusoidal projection fringe with the high ratio of light and contrast by a computer, and thus raises the ratio of resolution of the system and precision of the measurement. Phase-shifting is controlled by software accurately and all kinds of errors caused by traditional phase-shifting systems will be avoided.The basic principle of 3D measurement method based on digital phase-shifting and fringe projection techniques is illustrated in this paper. To the questions that exist in the system with traditional structure, the traditional structure is improved to remove parallel degree required in traditional structure for higher maneuverability in system calibration and higher precision of measurement. The mechanism of the non-linear distortion of the camera lens is carried on research. A kind of optimal method of the distortion coefficients of camera lens for improving the precision of the fringe projection measurement is proposed. Based on measuring the reference plane, the approach analyses the errors of some measure points on it, finds the relationship between the errors and the distortion coefficients of camera lens. Then the distortion coefficients of camera lens are determined by iterative optimization. This methodsolves the problem of the error caused by the distortion of camera lens effectively and the method to compensate for the error caused by the distortion of camera lens is given.更多还原