Theoretical And Experimental Research On Measuring Attitude And Velocity Of Moving Target

The research work of the dissertation is a pre-research project cooperated with PLA Second Artillery Forces to measure the attitude and velocity of moving target before landing. The actuality and development of shooting range measuring in the world are introduced, and the modern measurement methods in shooting range are analyzed in detail. According to the task and request, the binocular intersection measuring system has been set up to detect the attitude and velocity of moving target by high-speed image cameras synchronously. The scheme which takes full advantage of the advanced measuring and processing technique of machine vison and image processing is with simple structure, rapid responding speed, high measuring precision, and so on.The mathematics model of binocular intersection measuring system is set up firstly, and then the distribution modes and correlative parameters of binocular cameras are analyzed detailedly. The camera model taking account of radial distortion and the binocular cameras are calibrated by the RAC technique. The relations between effective viewing and image pixels, as well as inner parameters and structure parameters of binocular cameras are discussed as the two cameras are placed symmetrically, and the binocular cameras are calibrated too.Target recognition in complex background based on improved BP neural network is proposed in the dissertation. Median filter is adopted to get ride of the noise and an improved method of maximum classes square error is used to compute the threshold of the image segmentation. The target recognition system based on improved BP neural network is established as seven invariant moments serve as the input feature vector. The experiment results show that the image noise could be gotten rid of effectively and the image could be segmented exactly by the image preprocessing method put forward in the dissertation, and the recognition system acquires an excellent recognition result.Subpixel detection of beeline on image plane based on spatial moment and 3D reconstruction of spatial beeline is researched. First the LOG operator is used to locate the edge at the level of pixel quickly, and then the spatial moment is used to detect subpixel location of the discrete points of edge. The least square fitting is adopted to fit the subpixel edge points which have been detected by Hough transform, after having gotten rid of the camera lens distortion. Mathematics model of reconstruction of spatial beeline from image lines on two image planes is set up. The experiments show that the detection of beeline on image plane and 3D reconstruction of spatial beeline have acquired high precision.The measuring methods of attitude and velocity of rotary moving target are discussed. The binocular intersection measuring system has been set up near the landing area to detect the landing parameters of moving target by high-speed photograph. The polynomial function of target track 3D curve is fitted with the method of least square according the 3D coordinate of centroid at the different moments, so the moving speed could be obtained by calculating the derivatives of the polynomial function. Based on the characteristic of rotary targets, mathmatics model of axes-rotary method to measure the attitude of rotary targets is established. Three measuring methods were proposed to measure the pose according to the size of images in the camera planes. The systemic experiments show that the method proposed in the dissertation could meet the needs of measuring attitude and velocity of moving target with high precision and stability.Both theoretical and experimental researches are taken, then some creative theories and means are proposed and relevant experiments are completed.