光电工程, 2016, 43 (9): 39, 网络出版: 2016-12-09
利用三频外差实现的小视场三维测量系统
Three-dimensional Small-field Measurement System Based on Tri-frequency Heterodyne Fringe Analysis
三维测量 三频外差法 相移 时间相位展开 3D shape measurement tri-frequency heterodyne method phase shifting temporal phase unwrapping
摘要
搭建了一套小视场的三维面形测量系统。该测量系统采用基于DLP4500 芯片开发的高速数字投影模块套件实现条纹图像的高速投影和相机的同步触发图像采集。利用该投影模块向小视场物体表面投影三种不同频率的相移条纹图,相机同步记录受到物体表面形貌调制而发生形变的条纹,分别计算出三组条纹对应的截断相位图,再进行两次外差得到频率为1 的相位分布,以此为基准往回展开得到连续的相位分布,从而重建被测物体的三维面形分布。实验成功重建了以硬币为代表的小视场(8 mm×6 mm)物体在100 μm 深度范围内的表面三维形貌。
Abstract
A three-dimensional (3D) shape measuring system has been built. In the system, a high-speed digital projection module was developed with a DLP4500 chip and synchronously trigged with a CCD camera. Three different frequencies fringe patterns were projected onto the surface of a tested object in turns and were used to calculate the natural phase distribution, as well as the height distribution of the measured object by phase-shifting algorithm and heterodyne phase unwrapping method. Several practical experiments were carried out some tested samples in a small field of view (8 mm×6 mm). The results show that the system can restore the objects’ (coins for example) 3D shape (~100 μm) with a high accuracy.
艾佳, 刘守起, 刘元坤, 张启灿. 利用三频外差实现的小视场三维测量系统[J]. 光电工程, 2016, 43(9): 39. AI Jia, LIU Shouqi, LIU Yuankun, ZHANG Qican. Three-dimensional Small-field Measurement System Based on Tri-frequency Heterodyne Fringe Analysis[J]. Opto-Electronic Engineering, 2016, 43(9): 39.