Positioning And Guiding Method Based On Monocular Vision In The Large Space

Laser measurement network can be used to measure heavy equipment in the large space, and it needs to aim the key points on the equipment which is measured to make the final accurate measurement come true. The work people make the measuring instrument aim at the target manually is very easy to result at measurement error, missing key points, inefficient etc. Therefore, designing a set of positioning system which is used to guide instrument to aiming at the target automatically is the research issue needed to be solved.The Master paper is coming from the National Natural Science Fund Project (51275149), and the task of this paper is to use a single camera to measure space coordinates of the mirror in long distant. The target mirror is the 50mm diameter circular, so the accuracy of the positioning system should be controlled within 50mm in 10m. The research contents and results of this Master paper is as follows:(1) Summarized the research current situation based on visual measurements and location on domestic and foreign, and explained the significance of this paper relying on natural fund projects and introduced the research contents of monocular vision localization;(2) Built the final model of relationship between the image information and the spatial location of the target mirror, and used this model to research the affect of landmarks layout to location; According to the results of program simulation, the structure of the group identifier should be 8 points symmetrical layout, which layout intervals is 150mm;(3) Used Zhang Zhengyou calibration algorithm to calibrate the camera to obtain the internal parameters and distortion coefficients of the converting model between the target mirror’s location and image information;(4) Proposed an improved Harris corner detection method to extract useful corner; studied the sub-pixel corner detection method based on Gaussian curve fitting edge; the accuracy of landmark center’s image coordinates can reach to 0.127;(5) Tested and verified the positioning accuracy of the system, and the positioning error of monocular vision positioning can reach to (6.094,-4.597,-48.050) in 12 distant, which could guide the laser ranging system alignment to the target mirror.