基于车牌照模型的大地坐标系下车辆精确定位

Precise vehicle locating in geodetic coordinates based on the vehicle license plate model

为了对车辆位置进行快速准确定位,提出了一种基于车牌照模型来获取大地坐标系下车辆精确位置的方法。首先通过离线标定的摄像机参数,推导图像平面与道路平面之间的坐标转换关系;然后对感兴趣区域内的车辆进行身份识别,根据车牌照宽度和高度已知,以及车牌照平面与道路平面垂直的约束条件,建立车牌照模型来对车辆进行精确定位;最后引入东北天坐标系来实现车辆定位结果从图像坐标系到大地坐标系的转换。实验结果表明该方法能对车辆位置进行快速精确定位。

This paper presents a quick and accurate method to identify a vehicle position in a geodetic coordinate system based on a vehicle license plate model.The camera parameters are calibrated off-line to develop a coordinate transformation between the image plane and the road plane.Then,the vehicle is identified within the region of interest and the vehicle license plate model is used to precisely position the vehicle,since the vehicle license plate＇s width and height are known and the vertical distance between vehicle license plate plane and the road plane is constrained.Finally,an east-north-top coordinate is used to convert the vehicle positioning results from the image coordinates to the geodetic coordinates.Tests show that this method can quickly and accurately identify the vehicle position.