Research On Ranging Method Of Spacecraft Object Based On Optical Image

It is a hot focus in the field of optical measurements to estimate the position and orientation of the object by using the optical image of the object observed. The method of relative position estimate based on optical image has wide applications in autonomous navigation, computer vision and spacecraft docking. Taking the applications of smart robot experiments and small autonomous docking of space vehicles as background, this paper puts forward a method to measure the relative position of the object by using the optical imaging sensor in the proximity.Firstly, this paper expounds some basic image processing concepts that is frequently used in the visual measurement of space robot., studies and analyzes ordinary methods about image processing, which include image pretreatment, image segmentation and edge detection. During image recognition, it reduces the yawp and improves the quality of the image with the technology of the median filter, it uses the method of maximum between-class variance to segment the object, then gets better effect. the algorithm is simple, and the adapted capacity is great. It doesn't influence by the change between the contrast and lighteness of the image .So it applies on the real time system.Secondly, the paper studies the correlative theory of the camera and calibration algorithm. Since the camera lens used in computer vision sustain a lot of nonlinear distortion, recent research efforts has been concentrated on the distortion correcting technique. The optimization algorithms in conventional calibration field have shortcomings that the computing quantity is colossal. In order to improve it, Tsai two steps'algorithm was developed in conventional camera calibration in this dissertation, and a calibration algorithm considering radial distortion. Compared with the ordinary optimization algorithm of calibration, this algorithm is simple, less computational and high accuracy.Finally,the paper put forward the ranging method based on similar triangle principle. It gives two ranging models according cooperation object vertical in the optical axis or not vertical in the optical axis and does experiment. Experimental results and error analysis show that the algorithm can make certain...