迭代最小二乘椭圆拟合的锥套图像检测与跟踪  

Drogue image detecting and tracking based on iterative least squares ellipse fitting

作　　者：黄斌[1] 孙永荣[1] 杨博文[1] 王潇潇[1] 刘晓俊[1] 

机构地区：[1]南京航空航天大学自动化学院导航研究中心,南京210016

出　　处：《中国图象图形学报》2014年第8期1202-1209,共8页Journal of Image and Graphics

基　　金：国家自然科学基金项目(61174197);航空科学基金项目(2012ZC52045)

摘　　要：目的针对自主空中加油过程中锥套图像目标识别与定位问题,以锥套内部加油口作为匹配特征,提出一种基于圆形特征的锥套检测与跟踪方法。方法锥套跟踪采用行列扫描法获取锥套内部边缘,并通过迭代最小二乘拟合确定精确的椭圆形状参数,而锥套检测采用多方位最近点区域搜索法提取锥套所在的所有可能图像区域,并采用锥套跟踪进行精匹配和最终决策。结果实验结果表明,该方法下锥套精确定位的成功率高达94.71%,锥套检测耗时小于500 ms,锥套跟踪的最大耗时为21.59 ms,平均耗时4.18 ms。结论本文方法无须在锥套上额外安装光学标记,且能够实时、精确地确定锥套所在的图像位置和大小。Objective To overcome the shortcoming about the lack of payload and endurance,the autonomous aerial refueling technology is an effective solution for unmanned aircraft to extend flight duration,which results in exponentially enhancing of the aircraft fighting efficiency,and it can also reduce the refueling operation risk for manned aircraft.Relative position sensing between the receiver aircraft and the refueling drogue is the first and necessary step in the autonomous aerial refueling procedure,and the vision-based method is the mostly used for relative positioning.We propose a circular featurebased drogue detecting and tracking method by using the internal refueling port of drogue as the matching feature.Method The drogue tracking is the final step which outputs the final image positioning results even in the drogue detecting process.In drogue tracking,the rectangle of interest （ROI） of current frame image is determined and extracted depending on the positioning result in the last frame,and then the Canny algorithm is applied to obtain the ROI edge image.With the edge pixel points,the row and column scanning method is used to obtain the inside edge points of circular objects,which can exclude the irrelevant image pixel points,and then the precise elliptical shape parameters can be solved through an iterative least-squares fitting method.In drogue detecting,a multi-direction closest point searching method is proposed to extract all possible drogue image areas by inspecting the circular feature when scanning the multiple directions of the interested pixel point,and final result with precise matching can be decided by the drogue tracking method mentioned before.Result Experiments are designed and done with a drogue model which has almost the same size of the real refueling drogue.The Hough-based circle detecting method is treated as the comparison method,and simultaneously a laser rangefinder is used to provide the reference positions in the experimental procedure.Experimental results show that,the proposed me

关 键 词：自主空中加油 锥套跟踪 锥套检测 图像定位 最小二乘拟合 

分 类 号：V249.1[航空宇航科学与技术—飞行器设计]