Experiment Research Of Non-cooperative Space Target Relative Measurement Based On Binocular Vision

With the development of the space technology, the rendezvous and docking hasbecome more and more important. Relative measurement based on stereo vision plays thekey role in the process of rendezvous and docking, especially for non-cooperativemeasurement.In order to achieve the relative position and oritation measurement of non-cooperativetargets in short range, the binocular vision measurement technology is proposed in thisthesis. The main work is to design two binocular vision measurement systems, respectivelyfor the non-cooperative rectangular solar panels and round star arrow docking ring andengine nozzle which sizes are unknown. The ground based simulation system is alsoestablished in this thesis to verify the real-time performance and precision of the proposedmethods.The binocular vision measurement system for rectangular solar panels contains6functions: image preprocessing, feature point extraction, feature point matching,3-Dreconstruction, object recognition and tracking, relative position measurement. The Harrissub-pixel corner points extraction method is used to obtain feature information, theimproved feature points matching algorithm is developed to increase matching accuracy,after that, the geometric threshold strategy is used to recognize rectangular target, then theROI setting is helpful to achieve the tracking measurement. Finally the relative posemeasurement algorithm can calculate the relative pose information of target.The binocular vision measurement system for round star arrow docking ring andengine nozzle contains4functions: image preprocessing, the least-squares ellipse fittingmethod, imaging cone model, radius estimation by3-D reconstruction method. At first, inorder to recognize the target ellipse from background fast and efficient, a least-squaresellipse fitting method is designed; then the imaging cone model to determine the center ofcircle and the normal vector of target is established; at last, the radius of the target isdetermined by3-D reconstruction method.The ground based simulation system contains motion simulation sub-system and thevisual measurement sub-system. The visual measurement software， which compiled by C++, can control the measurement process. The experiment of the relative motion androtation, the velocity and angular velocity, etc., are simulated by this system. The goodperformance of the experiment demonstrated the validity of the proposed method in thisthesis.