基于PnP算法的前方车辆测距方法  

Method of measurement vehicle distance based on PnP

作　　者：李占旗 高继东 彭凯[2] 刘全周 许小伟[3] Li Zhanqi;Gao Jidong;Peng Kai;Liu Quanzhou;Xu Xiaowei(CATARC(Tianjin)Automotive Engineering Research Institute Co.,Ltd.,Tianjin 300300,China;Hebei University of Technology,Tianjin 300130,China;Wuhan University of Science and Technology,Wuhan 430000,China)

机构地区：[1]中汽研(天津)汽车工程研究院有限公司,天津300300 [2]河北工业大学,天津300130 [3]武汉科技大学,武汉430000

出　　处：《国外电子测量技术》2020年第12期104-108,共5页Foreign Electronic Measurement Technology

基　　金：国家自然科学基金面上项目(51975428);国家自然科学基金(51975426);天津市科技计划(17YDLJGX00020)项目资助。

摘　　要：针对路面起伏导致前方车辆距离测量偏差过大,提出一种基于PnP算法的前方车辆距离测量方法。以前方车辆的车牌作为靶标,采用深度学习算法SSD对车牌进行识别,获得车牌在图像中的位置坐标,根据PnP算法估计车牌的位姿,由相机的映射关系计算出目标车牌与本车的纵向和横向距离。该方法与地面是否起伏无关,仅与前方车辆车牌图像测量相关,通过靶标测试、虚拟场景和实际场景对算法的有效性进行测试,测试过程中表明,目标在5~30 m,车距的相对误差为1.4%,可实现较好的距离探测与预警。For a large measurement error due to the road surface fluctuation,a vehicle distance measurement method based on license plate image is proposed to measure distance in front of the vehicle.The vehicles’license plates are taken as the targets and the deep learning algorithm SSD is used to recognize these targets.he deep learning algorithm SSD is used to recognize the license plate to obtain the position coordinates of the license plate in the image.The position coordinates of the license plates in the image can also be obtained by the SSD algorithm.The position and posture of the license plate can be calculated by the PnP algorithm.The vertical and horizontal distance between the target license plate and the vehicle is calculated according to the mapping relationship.This method has nothing to do with whether the ground undulates or not,but only with the front vehicle license plate image measurement.The effectiveness of the algorithm is tested through target testing,virtual scenes and actual scenes.The test process shows that the target is within 5~30 m and the relative error of the vehicle distance is 1.4%.It can achieve accurate distance detection and warning.

关 键 词：车距测量 车牌 PnP算法 相对误差 

分 类 号：U491.6[交通运输工程—交通运输规划与管理]