基于单目视觉的电动公交车自动更换电池系统

AUTOMATIC BATTERY- CHANGING SYSTEM FOR ELECTRIC BUSES BASED ON MONOCULAR VISION

目前电动公交车所用电池沉重而体积大,人工更换时存在挪动调整费力、精确定位困难等问题。针对这些问题,提出一种基于单目视觉的电动公交车自动更换电池系统。该系统使用单目摄像机获取图像,对蓄电池箱的空间位姿进行测量,再通过两级导轨和旋转机构将蓄电池调整到指定位置。位姿测量时采用基于点特征的单目视觉测量算法,提取蓄电池箱的四个角点作为特征点,根据特征点在物体坐标系下以及在CCD成像面上的坐标值,在空间投影模型的基础上求解出物体坐标系相对于摄像机坐标系的变换矩阵,从而求得蓄电池箱的空间位姿。实验证明该方法具有较高的可靠性,并且满足实际问题的精度要求。

At present,storage batteries used in electric buses are heavy and large-sized so that it is very hard to manually move and locate them to battery boxes. To solve these problems,an automatic battery-changing system for electric buses batteries based on monocular vision is proposed. In the suggested system,a monocular camera is used to locate the image and to measure the spatial position and attitude of storage battery box. Then two-level guiderails and a rotating mechanism are used to move the storage battery to the specified position. The monocular vision measuring algorithm based on point feature is used to measure the position and attitude relative to the battery box. Four corner points of the battery box are extracted as the feature points. The transformation matrix of the object coordinate relative to camera＇s coordinate is calculated on the basis of space projection model according to the coordinates of these feature points in the object coordinate system and the CCD image plane coordinate system. Then the spatial position and attitude relative to battery box are worked out. Experiments show that this method is highly reliable and meets the accuracy requirement of the practical problem.