单镜头运动颗粒三维定位方法  

Method of three-dimensional positioning for moving particles with single lens

作　　者：金娜[1] 周骛[1] 胡嘉睿 蔡小舒[1] 

机构地区：[1]上海理工大学能源与动力工程学院,上海市动力工程多相流动与传热重点实验室,上海200093

出　　处：《中南大学学报（自然科学版）》2016年第9期3246-3251,共6页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51206112,51327803);上海市自然科学基金资助项目(12ZR1446900);上海市教委科研创新项目(12YZ110)~~

摘　　要：在光学离焦测距原理的基础上,提出一种采用单镜头双相机的运动颗粒三维定位方法,搭建图像法颗粒测量装置,并就图像离焦模糊度与颗粒深度位置关系进行理论和试验研究。系统采用分光棱镜连接1个镜头和2个相机,使用信号发生器实现两相机的同步拍摄,通过接圈调节相机与镜头的距离,获取同一时刻同一物体不同模糊程度的2张照片,根据模糊度的对比获得颗粒的深度。试验中选取2个图像传感器与镜头距离的差值为4.2 mm,采用静止圆点进行离焦测距系统试验验证,相对误差在10%以内,并采用该系统对电解食盐水产生的气泡进行三维离焦测距试验。研究结果表明:该方法可行性良好;该装置可解决单镜头拍摄颗粒场的离焦二义性问题,实现无参考物条件下运动颗粒场的深度重构。Based on the optical principles of depth from defocus（DFD）, a method with a single lens and two image sensors was proposed to determine the three-dimensional positions of moving particles and an imaging system was established for measurement of particle locations. The theoretical and experimental analyses were carried out to explore the relationship between defocus blur degree of image and particle depth. A dispersion prism was used to connect a lens and two cameras, and synchronous measurement was realized with a signal generator. Two images with different defocus blur degrees could be captured for the same particle by adjusting the distances between the two image sensors and the lens. The depth information could be extracted from these two images. The distance difference between two image sensors and the lens was adopted as 4.2 mm. The validation experiments of the measurement system were carried out using static particles, in which the relative measurement errors were within 10%. And the three-dimensional defocus distance test was carried out for bubbles produced by electrolysis of salt water using the system. The results show that this method well feasible, and the problem of position blur in DFD with single lens can be solved using this setup, which indicates that DFD without references can be realized.

关 键 词：运动颗粒 单镜头双相机 离焦测距 空间定位 离焦二义性 

分 类 号：TH7[机械工程—仪器科学与技术]