摘要： 为减小特征匹配以及摄像机光轴倾斜对单目测距造成的误差,提出一种基于单目视觉的轮式移动机器人目标测距方法,将测距目标从平面物体推广到立体物体,在无须校正的情况下提高测量精度。通过对摄像机进行标定测量其内外参数,建立小孔平面成像模型得到世界坐标系与像素坐标系的对应关系。针对坐标变换矩阵奇异的情况,引入面积这一特性进行求解,推导特定矩阵奇异情况下目标距离与像素面积的关系。实验结果表明,该方法可将综合误差率控制在0.7%以内,能够满足轮式移动机器人单目视觉测距实时性和可靠性的要求。

关键词: 轮式移动机器人, 摄像机标定, 单目测距, 立体物体, 小孔平面成像

Abstract: In order to reduce the deviation brought by feature points matching and optical axis inclination,this paper proposes a new method to measure the target distance for wheeled mobile robot based on the monocular vision,which can extend the plane objective to the three-dimensional one and achieve high measurement accuracy without adjustments.Firstly,it extracts internal and external camera parameters by camera calibration.Secondly,by establishing the pinhole imaging model,it sets up the corresponding relationship between world coordinate system and pixel coordinate system.Then,with respect to the singularity caused by matrix transformation,it introduces the concept of area and obtains the relationship between target distance and size of pixel area under a specific singularity case.Experimental results indicate that the comprehensive error ratios of the proposed method are all under 0.7%,which can satisfy the system requirements of instantaneity and reliability for monocular distance measurement of wheeled mobile robot.

Key words: wheeled mobile robot, camera calibration, monocular distance measurement, three-dimensional object, pinhole plane imaging

中图分类号: 

• TP242.6