Measuring Technologies For Static Parameters Of Special Type Tube With High Precision Based On Photoelectric Imaging

High precision special type tube is widely used in many fields such as weapon, spaceflight and nuclear energy etc. Measurement of the static parameters is a prerequisite and important technique process in designing, studying and use of the special type of tube. With the development of study, manufacture and requirement of application, the classic measurement method based on optics glass and data processing artificially cannot satisfy new requirements of the special type of tube. A kind of high precision, high efficiency, and automatism measurement system need be constructed urgently.Based on thorough study of the measuring principle, measuring method and performance and limitation of the special type of tube, a project to the tube static parameters measurement system with high precision and automatism are designed which integrate the technical of optical, fine mechanism and electron. The critical technical in image obtain, image process, image measurement and data process is studied deeply to the point of accuracy photoelectric imaging measurement in special type tube complex environment during the design. As a result, a series of suitable technologies have been put forward. The feasibility and effectiveness have been verified by practice.Firstly, because an excellent image must be obtain in the special and complex imaging environment, artificial illumination method should be used. In order to get a relatively "good" image, a scene illumination system design idea has been used and a kind of distributed-LED artificial illumination light source which fits the image obtain in special and complex image environment has been designed and practice shows that the designing can ensure obtain high quality image for measure in the special and complex image environment.Secondly, benefit from LED illumination light source, the image quality is improved in some degree but far from the requirement of high precision measurement and include some noise still. So a series algorithms which suit image obtained in the special and complex environment, such as the image denoise means mixed wavelet and self-adaptive median filter, the image enhancement based on human visual property and generalized fuzzy operator have been adopt here,and a novel nonuniform illumination background suppress algorithm based on markov random field model designed. Simulation and test shows that these image preprocess algorithms can improve the SNR greatly and can meet the requirement for the image quality of the later image process. At the same, as the classic image segmentation methods cannot satisfy the need of high accuracy image measurement of special tube, some new methods are put forward to suit the segmentation special image, which include the multi-threshold image segmentation algorithms based on ant optimization and maximum fuzzy entropy, the concentric circles adaptive high accuracy detection algorithms based on local diameter Hough transform. Simulation and test indicate the image process methods can satisfy the need of the subsequent image measure.Thirdly, in order to realize the special type tube static parameters high accuracy measurement, we invent some new algorithms which include the sub-pixel edge detection algorithm for laser spot based on gauss plotfit and sub-pixel detect algorithms for rule target based on wavelet transform and Zernike moments; Simultaneity, in consequence of the lens distortion serious influence the measurement precision, a few lens calibrating and correction methods are construct such as the lens radial distortion calibrating method based on moving feature target, the lens radial distortion correction algorithm based on recursive least squares, the geometrical distortion correction method based on property parallel lines. Moreover, after analyzing the system-error in detail, a kind of camera rotation compensation algorithms based on sequence image frame feature matching. Result shows that the methods can improve the image measurement accuracy and can reduce even eliminate the error.Lastly, the measurement mathematical model are construct partly, the tube space three-dimension axial reconstruct algorithm based on Cubic NURBS plot-fitting and the power chamber volume reconstruction based on three order spline interpolation algorithm are put forward, and these algorithm can get super effect. Meanwhile, aim at the portable design a real-time hard-ware project based on DSP is designed.