Monocular recognition measurement method based on the geometric model of the drogue

In order to precisely obtain the relative distance between probe and drogue during unmanned aerial vehicle(UAV) autonomous aerial refueling docking,a monocular vision method based on the geometric model for identifying refueling drogue and measuring the relative distance between probe and drogue is presented.In this method,firstly,using edge detection algorithm to get edge segment of image including refueling drogue,and connecting the line segments with the same deflection direction into circular arcs.Secondly, fitting circular arcs with similar radius and center into candidate circles,and validating candidate circles to obtain true circles.Thirdly,detecting lines in the true circles,and the drogue recognition is completed according to the characteristics of the drogue model.Finally,according to the known information of the drogue and the recognition drogue,the relative distance between probe and drogue can be measured. Especially,the method can be used to detect drogue accurately and has good performances in images when there are interfering objects.The experiment results show that the method has high real-time performance and high measurement accuracy,can fulfill the demand of probe and drogue aerial refueling.