光笔式大视场三维视觉测量系统  

Light probe based large FOV 3D vision measurement system

作　　者：冯萍[1] 魏振忠[1] 

机构地区：[1]北京航空航天大学精密光机电一体化技术教育部重点实验室,北京100191

出　　处：《光学精密工程》2013年第9期2217-2224,共8页Optics and Precision Engineering

基　　金：国家重大科学仪器设备开发专项--列车轮对/车体运动状况在线运动测试仪(No.2012YKU14032)

摘　　要：针对先进制造业对大型装备大范围精密尺寸测量需求,根据双目立体视觉测量原理设计了一种光笔式大视场三维视觉测量系统。基于透视投影变换下的时针顺序和共线性不变量设计了光笔特征点空间分布模式,实现了特征点的准确识别与接触探头坐标的计算。应用双目立体视觉传感器的透视投影和齐次坐标三维测量模型,以一维基线尺靶标自由移动和基准长度约束为核心,通过本质矩阵E的线性求解结合非线性优化实现了其结构参数的现场精确标定。研制了由光笔、双目立体视觉测量系统、便携式三脚架、一维基线尺靶标和测量软件构成的大视场三维视觉测量系统,完成了机器人本体表面三维数据的稠密测量实验,在7 m×4.7 m测量范围内系统的测量精度优于0.2 mm。实验显示设计的光笔式大视场三维视觉测量系统在光笔结构、发光点识别方法和系统标定方法上均具有新的思路。To meet the requirements of large-scale equipment for large scope precise measurement in advanced manufacturing industry, a light probe based large Field of View（FOV） 3D vision measure- ment system based on the binocular stereo vision principle was proposed. The spatial distribution mode of the character points on the light probe was determined according to the invariants of clockwise direction and colinearity under a perspective projection, hy which the character points were recognized and the coordinates of the probe were calculated. By using a 3D measurement model based on perspec- tive projection and the homogeneous coordinates of a binocular stereo vision sensor, the structure pa- rameters of the binocular stereo vision sensor were calibrated through linearly solving the essential matrix E, further following with nonlinear optimization by freely moving a 1D target with known pre- cise length. A true large FOV 3D vision measurement system was constructed, which consists of a light probe, a binocular 3D vision measurement system, a portable tripod, a 1D target and a set of measurement software. The real experiment to measure the dense 3D data was performed on a robot body surface in a field of 7 m× 4.7 m and the accuracy better than 0.2 mm was achieved. These re- sults show that the designed system has improvement in the light probe structure, recognition meth- ods of luminous points and the system calibration methods.

关 键 词：三维视觉测量 大视场 光笔 标定 光斑识别 

分 类 号：TP242.6[自动化与计算机技术—检测技术与自动化装置] TP391[自动化与计算机技术—控制科学与工程]