Measurement and calibration of mass imbalance for rotors are often indispensible as mass imbalance will cause undesired vibration and present serious problems accordingly. In this study, a new method based on digital ...
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Measurement and calibration of mass imbalance for rotors are often indispensible as mass imbalance will cause undesired vibration and present serious problems accordingly. In this study, a new method based on digitalimageprocessing (DIP) to measure the mass imbalance of a special rotor with air suspension is introduced. By hunting the trace of tilt angle through several identification points on the rotor by DIP, the corresponding oscillating period will be determined, which in turn contributes to the calculation of mass imbalance. Two-dimensional monochrome charge-coupled device (CCD) and peripheral component interconnect (PCI) image board are applied in the experiment to capture the rotor's image, and several user interfaces are developed for imageprocessing and curve fitting as well. Besides, the system error analysis and the comparison of experimental results with that of other related work are provided, which prove the effectiveness and accuracy of this DIP method.
We present an improved digitalimageprocessing(DIP)method to calculate the widths of single *** from the traditional laser Fraunhofer diffraction experiment in college physical experiments,by performing fast Fourier ...
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We present an improved digitalimageprocessing(DIP)method to calculate the widths of single *** from the traditional laser Fraunhofer diffraction experiment in college physical experiments,by performing fast Fourier transform,inverse fast Fourier transform and the nonlinear leastsquare fitting on the diffraction pattern taken by a camera,the DIP method can quickly return an analytic expression,whose period is used to calculate widths of single *** comparing the measured results by the DIP method and the successional difference(SD)method,we find that for a single slit whose width is 60372μm,the DIP method is more *** results show that for single slits with widths between 40μm and 160μm,the relative error of the DIP method is less than 2.78%.Also,the DIP method can be used to measure the diameter of filament and fibres online in real time.
In this research, digital image processing method (DIPM) is used as an innovative approach to predict precisely the shape of electrical tree (ET) in cross-linked polyethylene (XLPE) power cables in the presence of air...
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In this research, digital image processing method (DIPM) is used as an innovative approach to predict precisely the shape of electrical tree (ET) in cross-linked polyethylene (XLPE) power cables in the presence of air voids based on the field calculation using finite-element method (FEM). With the help of DIPM, two case studies are held to detect the accurate parameters of either the first initiated major branch or the tips of the major branches of ET. A hyperbolic needle-to-plane simulation model is proposed to illustrate the ET inception and propagation stages. The non-uniform electric fields thatare accompanied with the electrical treeing phenomenon are calculated using FEM as one of the most effective numerical methods to deal with non-uniform shapes. The predicted shapes of ET initiation and growth are provided in an innovative manner with the implemented hybrid connection between FEM and DIPM for the two proposed case studies. Direction branching approach and deviation angle branching approach are provided in this work to predict the shape and the direction of ET branched voids. The validity of the proposed model is assessed with the help of available previous experimental and simulation data.
Although the image of discharge in the nanosecond time scale can provide some details of a single discharge, the essence of gas discharge remains random under the same macroscopic physical conditions. Therefore, the s...
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Although the image of discharge in the nanosecond time scale can provide some details of a single discharge, the essence of gas discharge remains random under the same macroscopic physical conditions. Therefore, the statistical evaluation of discharge images including a large number of stochastic processes in a long-time scale is still of great significance. In this paper, a digital image processing method presented in our previously paper is used to research the statistic indicators of AC corona discharge image in the time scale of seconds, and the axial distribution of the average gray level and the gray level standard deviation about corona discharge image are determined. Then, these statistical indicators are utilized to study the long brush-like corona, and a clear "stem" caused by the point electrode and not by the ball head electrode was found, even if they all belong to the highly non uniform electric field. Considering its corresponding current pulse rise time, we believe that the leader discharge also exists in the cm-level short gap. These results indicate that the statistical analysis on the longtime scales can be used in discharge research, and further image information mining will likely be used to provide some new characteristic parameters.
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