| The measurement based on the stereo vision is one of the important techniques in the non-contact measurement. The stereo vision measurement is an effective method for measurement when the object’s size is relatively large, flexible and non-contact. The main study destination of this thesis is the study of characteristic targe ts, namely the design of new kinds of characteristic targets,the detection and location of the characteristic targets and the study of the coding and decoding algorithm. The new characteristic targets have been used in the high accurate measurement of the hoop-rib deployable antenna structure.Firstly, the thesis have a study and analysis of the common pattern- circular used in the characteristic targets and have a summary of the detection algorithm of the circular characteristic targets and sub-pixel edge detection. The simulation experiment is carried out. Have an analysis of the eccentric problem after affine transformation and use the cross ratio invariant of the concentric to realize eccentric correction. Considering the disadvantage of the circle pattern, a new characteristic target pattern-concentric is proposed in the thesis.Secondly, considering the disadvantage of the existing coded targets, two kinds of improved schemes of coded targets are proposed. Then, introduced the code theory of the two improved coded targets and the algorithms of recognition and decoding of coded targets. The algorithms are proved by the simulation experiment.Finally, the two kinds of coded targets are used in the practical measurement of the three-dimension stereo visio n. The new coded targets have been placed on the hoop-rib deployable antenna structure and are decoded in the image, and then the three-dimension coordinates of the coded targets are calculated which are compared with the coordinates measured by the three-dimension photogrammetry system of Tian Yuan. The results are used to prove the schemes of characteristic targets are reasonable. |
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