基于机器视觉的微工作台位姿三点法测量

Three-point Method on Pose Measurement of Microstructure Stage Based on Machine Vision

基于机器视觉,提出一种全行程检测六自由度微工作台三维运动位姿的新方法,此方法可利用单目视觉来实现目标的三维位姿检测。用三个固定在微工作台上的标准球的球心作为标志点表征工作台在三维空间的位姿,通过固定好的摄像机对工作台上三个标准球在三维空间的视觉跟踪,检测标准球在视野中位置和直径的变化,判断球心在固定坐标系的三维坐标,建立图像空间与物空间的映射模型,得到工作台在三维空间的位姿,进而检测到工作台在每个采样时间的运动误差。

Based on machine vision,this paper describes a new method that measures the error of six degrees of freedom micro-displacement table 3D pose.The method can measure the place and stance of 3D targets by monocular vision.The centre of three fixed standard small spheres at micro-displacement table as mark points characterizes the pose of table in 3D space.The fixed camera traces the spheres at table by vision in 3D space and the quantitative changes of spheres’ position and diameter in eyeshot are ascertained in the 3D coordinates.The mapping model from image space to natural space is built.By this way the pose of table in 3D space is ascertained and the kinematics error of table at every sampling time is measured.