University of Electronic Science and Technology of China

Libing Bai

Yuhua Cheng

Kai Chen

Bo Xu

Jia Zhao

Songting Zou

Hang Geng

Yanjun Yan

Jie Zhang

Chun Yin

Chao Ren

Xu Zhang

Yong Duan

Yiping Liang

Xue Chen

Yali Zheng

Jinliang Shao

Yonggang Wang

Lulu Tian

Xiaoyu Huang

Shuai Shi

Ruiheng Zhang

The present invention provides a method for eddy current thermography defect reconstruction based on electrical impedance tomography, first, obtaining a thermal reference image of temperature change with time by acquiring a thermogram sequence S of the specimen in the process of heating and fitting a curve for pixels of each location of the thermogram sequence S, then, creating a current matrix and a magnetic potential matrix, and calculating the satisfied conductivity distribution through iterations, so as a reconstructed image is obtained, then taking the low conductivity area of the reconstructed image as the defect profile, thus the defect profile is identified and quantified.

Method for eddy current thermography defect reconstruction based on electrical impedance tomography

The present invention provides a system for data mapping and storing in digital three-dimensional oscilloscope, wherein the fixed coefficients, which are calculated according the parameters and settings of a digital oscilloscope, are stored into a fixed coefficient memory CO RAM, the fixed coefficients are outputted to N fractional operation units through N−1 D flip-flop delay units to multiply with the acquired data x(n) and then be accumulated, thus N fractional calculus results are obtained. In this way, N fractional calculus results can be obtained by performing L/N fractional calculus operations. N fractional calculus results are sent to a signal processing and display module, in which they are converted into a display data through a drawing thread, and the display data are sent to LCD for displaying, thus the fractional calculus operation and display of a input signal in a digital oscilloscope is realized.

Digital oscilloscope having fractional calculus operation and display function

A system maps and stores data in digital three-dimensional oscilloscope, wherein an ADC module has four ADC submodules. Four acquired waveform data are sent to an extraction module, and buffered in a FIFO module. When a trigger signal arrives, FIFO module outputs four extracted waveform data to a mapping address calculation module for calculating a mapping address and a RAM serial number for each point data, and the waveform data comparison and control module performs the reading and writing control of the 4&#xd7;N dual port RAMs. When mapping number reaches a frame number, the RAM array module outputs its waveform probability values to the upper computer module to convert each value into RBG values, and the display module displays the waveforms of input signals of four channels on a screen according the RBG values.

System for data mapping and storing in digital three-dimensional oscilloscope

The present invention provides a method for simulating magnetic flux leakage based on loop current, the magnetic distribution of a single loop current is obtained by solid angle, then the magnetic field distribution of a semi-infinite solenoid is obtained based on the assumption of arrangement of loop currents in the magnetized specimen, and its equation is given; and the JA hysteresis model is introduced to obtain the distribution of quasi-static magnetic flux leakage field, on the basis of analyzing the relation between the distribution of a loop current on the surface of the defect and the excitation magnetic field, the distribution of quasi-static magnetic flux leakage field is obtained based on the semi-infinite solenoid.

Method for simulating magnetic flux leakage based on loop current

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Chengdu, China

Libing Bai