基于PTZ摄像机的行车吊钩主动跟随算法  

An Active Following Algorithm for Crane Hooks Based on PTZ Camera

作　　者：朱林 龙永红[1] 胡聪崴 ZHU Lin;LONG Yonghong;HU Congwei(College of Railway Transportation,Hunan University of Technology,Zhuzhou Hunan 412007,China)

机构地区：[1]湖南工业大学轨道交通学院,湖南株洲412007

出　　处：《湖南工业大学学报》2023年第5期1-8,共8页Journal of Hunan University of Technology

基　　金：湖南省自然科学研究青年基金资助项目(2020JJ5144);湖南省教育厅科学研究基金资助项目(19C0563);2022年度省市联合基金资助项目(20221150088)。

摘　　要：传统固定式摄像机由于其监控的狭隘性与被动性,无法自适应调整其焦距值来获得目标清晰图像,使得行车吊钩跟随具有较大的挑战性。因此,提出一种基于PTZ摄像机的行车吊钩主动跟随算法。首先通过摄像机标定求解摄像机初始状态角度和内置参数K中的焦距值,利用几何投影关系,建立摄像机与车间坐标系的动态成像模型,根据模型和行车吊钩位置估计摄像机的P、T、Z值;然后针对高分辨率图像逐渐偏移图像中心区域的问题,采用特征点自动对准算法,二次计算摄像机的P、T增量;最后基于估计的P、T、Z值及其增量,调用摄像机接口函数进行姿态调整,使行车吊钩始终位于图像中心,完成主动跟随任务。实验结果表明,该算法可以很好地适用于大视场下的目标跟随。同时,该算法需要实时采集目标点的世界坐标,因此同样适用于装有GPS定位设备或者距离传感器等的目标跟随。Due to the narrowness and passivity of the traditional fixed camera monitoring,as well as its inability to adjust the focal length values to obtain clear images of the target,crane hook following is confronted with a significant challenge.Therefore,an active following algorithm has thus been proposed for crane hooks based on PTZ camera.Firstly,a calculation can be made of the initial state angle of the camera and the focal length value in the built-in parameter K through camera calibration.By using geometric projection relationships,a dynamic imaging model can be established between the camera and the workshop coordinate system,followed by an estimation of the P,T,and Z values of the camera based on the model and the position of the crane hooks.Then,in view of the problem of high-resolution images gradually shifting from the center area of the image,a feature point automatic alignment algorithm is adopted for a calculation of the P and T increments of the camera twice.Finally,based on the estimated P,T,Z values and their increments,the camera interface function is called to adjust the attitude,so that the crane hook is always located in the center of the image,thus completing the active following task.The experimental results show that the proposed algorithm can be well applied to target tracking in a large field of view.Meanwhile,the algorithm requires a real-time collection of the world coordinates of the target point,which makes it applicable to target tracking equipped with GPS positioning equipment or distance sensors as well.

关 键 词：PTZ摄像机 主动跟随 动态成像模型 自动对准 

分 类 号：TP273.2[自动化与计算机技术—检测技术与自动化装置]