| Three-dimensional reconstruction is to create mathematical model forthree-dimensional objects by computer representation and processing, this model is thebasis for storing, processing and analyzing the nature of object by computer, which is keytechnology to express objective world in computers.When loaded circuit switches, electric arc will happen between the contact of lowvoltage electrical apparatus, which is the main factor affecting the life of low-voltageapparatus. The generation and shape of low-voltage electrical arc and arcing motionprocess play importment roles in the analysis of switch capability, electrical life as well aselectrical failure. Therefore, to improve the reliability of low-voltage electrical products, itis necessary to research the dynamic change of the whole process from arcing start to thearcing end, and to research the impact of various factors on the process of arc movement.Because switch arc arcing process is very short, it is not suitable for direct observation andanalysis. To establish visualization model for arc arcing process helps to conduct in-depthresearch, analysis arc characteristics of the arc arcing mechanism, so as to achieveimproved electrical structural design, improved electrical materials and improved thereliability of electrical products. Therefore, to carry out research work on this subject hasimportant theoretical significance and practical value.Based on a comprehensive analysis of existing visualization techniques, thelow-voltage contactor switch arc image acquisition system was proposed, which wasbased on high-speed CCD camera. A system of hardware and software system structurewas designed to acquire arc image and then do three-dimensional reconstruction. Theoryand technology researches on three-dimensional reconstruction process such as edgedetection, feature point matching, image enhancement, camera calibration, surface fittingwas carried out and related solutions was proposedEdge detection is the basis for a variety of three-dimensional computer reconstructionalgorithm, impacting directly on the effect of the three-dimensional reconstruction. In thispaper, concerning the characteristics of the arc image, a profit and loss modified edgedetection algorithm was established based on uniform B-spline with shape parameter, which use uniform B-spline with shape parameter formula to fit the modified imagesurfaces, the image was obtained by calculating the feature points. This method wassimple, high precision, and easy for real-time processing.Feature point is an important feature of images, and plays an important role inthe field of three-dimensional reconstruction. This paper proposed a multi-featurefusion image matching algorithm. Feature points were obtained through SIFTalgorithm, the SIFT algorithm was improved as well. By a zoom doubled processingon the image before the Gaussian and the convolution to improve the speed of thefeature point extraction. Gradation and distance of the feature point were combinedtogether to describe a feature point, and to calculate the degree of similarity betweenthe feature points, these characteristics can describe localized feature better. Usingthis method, we can effectively reduce the number of false feature points, preciselylocate the feature point, and effectively improve the recognition efficiency. To retainthe characteristics of the arc column, the histogram-based image enhancementalgorithm was used; better effect on image enhancement was achieved.Finally, the arc image calibration algorithm was proposed, and based on non-uniformrational spline surface fitting algorithm, visual simulation model of the low-voltageelectrical switch arc was achieved, arc breaking simulation model was achieved. Theelectric arc interrupter movement process was displayed through computer simulation; itwas convenient to observe and analyze the arc from different angles. The application ofarc visual model can improve the electrical design and benefits the electrical apparatusindustries a lot. |
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