一种利用结构光照明的高精度三维测量系统

High-resolution three-dimensional measurement system based on structured light illumination

为了实现对微小物体的高精度三维测量,本文构建了一套基于结构光照明的三维形貌测量系统,对该系统所使用的相位编码算法、远心相机标定算法和投影仪标定算法进行了研究。首先,通过边缘提取算法获得二维平面标靶的特征点坐标,使用改进的张氏标定算法完成远心相机标定,通过相位编码结构光得到相机像素与投影仪像素之间的映射关系。然后,由映射关系使投影仪也能捕获特征点的位置信息,进而完成投影仪标定。最后,基于立体视觉模型对被测物体进行三维重建。实验结果表明,标定后的测量系统视场大于2000 mm^(2),全视场的测量精度约为32μm,中心视场的测量精度为10μm。该系统具有良好的稳定性和重复性,能够满足大多数工业检测的应用需求,展示出广阔的应用前景。

In order to achieve high precision 3D measurement of small objects,a set of 3D shape measurement system based on structured light illumination is constructed in this paper.The phase coding algorithm,the calibration algorithm of telecentric camera and the calibration algorithm of projector used in this system are investigated.First,the coordinate of feature points of two-dimensional planar target is obtained by edge extraction algorithm,and an improved Zhang′s calibration algorithm is used to complete the calibration of the telecentric camera,and the mapping relationship between camera pixels and projector pixels is obtained by using phase encoded structural light.Then,the mapping relationship enables the projector to capture the position information of feature points,and then complete the calibration of projector.Finally,based on stereo vision model,the object is reconstructed in three dimensions.The measured results show that the calibrated measuring system has a field of view greater than 2000 cm^(2),the measurement accuracy of full field of view is about 32μm,and the measurement accuracy of center field of view is 10μm.It has good stability and repeatability,and can meet the requirements of most industrial testing applications,having a broad application prospect.