Research On Calibration Method For Camera With Large Field Of View Based On Model Of EICC

Now, the measurement system based on computer vision has been increasingly used in aerospace industry processing, assembling, quality inspection, and other links. Its camera calibration precision of the measurement core parts directly affects the performance of the whole visual measuring system. In the aviation industry, the scope of parts assembly and testing are usually 2 to 20 meters wide field. In order to ensure the wide field vision measurement system precision, targets should be as possible full of the entire field of view. Because the large size of two-dimensional or three-dimensional target is difficult to process and target location accuracy is difficult to guarantee, Multiple small size two-dimensional target are usually combined into big size of two-dimensional or three-dimensional targets. However, the existing target combination should make various targets to be met coplanar, know the location of the strict relation between small targets, can’t make any changes in the process of calibration, and need other constraint conditions. In order to break through the limitations of existing methods, this paper puts forward a large field of view Camera Calibration based on Expediently Implemented Camera Calibration(EICC) model method and researches its related features. The main research contents and results are as follows:1, The paper puts forward wide-field camera calibration based on the EICC model method.1) According to the characteristics of the wide field calibration, the design method of Multi-azimuth targets is proposed. Multi-azimuth target solved the processing difficulties of large size targets, question of inconvenient to carry and transportation problem.2) To obtain the feature information of the Multi-azimuth target. Experimental results show that the method can accurately obtain the feature point information, and accurate sorting, This lays a solid foundation for calibration parameters of this EICC model.3) Obtain wide field calibration parameters. The experimental results show that the method can avoid the problem the direct using genetic algorithm into the local optimum or the actual problems of seeking internal deviates from the value, and improve the calibration precision large field of view.The paper compares the proposed EICC model calibration method and the traditional plane calibration method(checkerboard target and circular feature points were used to target respectively). And the experimental results show that the calibration precision of the EICC model is better, and the EICC model is feasible.2, Analysis related features of EICC model calibration.1) Through the analysis that Multi-azimuth targets placing distance and Multiazimuth target size affect EICC model calibration error, the paper obtains the target Area and optimal position relations – Area-Position Relation(APR). In the actual wide field calibration, according to the field of size and APR known, the paper guides the experiment to determine the optimal distance between Multi-azimuth targets, so as to improve the calibration accuracy.The paper puts forward the design method of Multi-azimuth targets, and greatly improve the convenience of calibration. Then the paper advances a kind of wide field camera calibration method based on the EICC model, and analyzes the characteristics of the method to obtain APR relation. The APR relation can guide the placement of the wide field calibration target location to determine the optimal distance between the targets, thus reduce the calibration error.