University of Electronic Science and Technology of China

Yuhua Cheng

Kai Chen

Chun Yin

Libing Bai

Xuegang Huang

Bo Xu

Ting Xue

Jia Zhao

Haonan Zhang

Songting Zou

Hang Geng

Yanjun Yan

Gen Qiu

Fei Wang

Yi Bu Li

Jie Zhang

Yang Yang

Jing Jiang

Chao Wang

Zezhan Zhang

Jun Hu

Yueming Wang

Houjun Wang

Hongchuan Jiang

Jiexiong Ding

Li Du

Xiao Yang

Chengui Zhang

Zeqi Wang

Xutong Tan

Zhibo Li

Aolin Yang

Jianhao Luo

Anhua Shi

Junjie Liu

Lulu Tian

Xiaoyu Huang

Ruiheng Zhang

Yiping Liang

Chao Ren

Xu Zhang

Yonggang Wang

Yong Duan

Yali Zheng

Shuai Shi

Jinliang Shao

Xue Chen

Yinze Wang

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 method for high-precision true color three dimensional reconstruction of mechanical component. Firstly performs image acquisition: the left and right high-resolution grayscale cameras are fixed at same height and spaced at certain distance, an optical transmitter fixed between the two grayscale cameras, and low-resolution color camera fixed above optical transmitter, thus images of measured high-precision mechanical component are shot. Then performs image processing: all images are transmitted to a computer, which uses image processing to record surface information of measured high-precision mechanical component in the point cloud by high-precision true color three-dimensional reconstruction, which reflects color texture information of the surface, so as to realize the non-contact high-precision true color three dimensional reconstruction of high-precision mechanical component. The method uses binocular high-precision grayscale cameras instead of binocular color cameras, which broadens the range of capture wavelengths, retains richer texture details of high-precision mechanical component and improves accuracy of measurement.

Method for high-precision true color three-dimensional reconstruction of a mechanical component

The present invention provides a method for quantitatively identifying the defects of large-size composite material based on infrared image sequence, firstly obtaining the overlap area of an infrared splicing image, and dividing the infrared splicing image into three parts according to overlap area: overlap area, reference image area and registration image area, then extracting the defect areas from the infrared splicing image to obtain P defect areas, then obtaining the conversion coordinates of pixels of defect areas according to the three parts of the infrared splicing image, and further obtaining the transient thermal response curves of centroid coordinate and edge point coordinates, finding out the thermal diffusion points from the edge points of defect areas according to a created weight sequence and dynamic distance threshold &#x3b5;&#xd7;d, finally, based on the thermal diffusion points, the accurate identification of quantitative size of defects are completed.

Method for quantitatively identifying the defects of large-size composite material based on infrared image sequence

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 separating out a defect image from a thermogram sequence based on weighted naive Bayesian classifier and dynamic multi-objective optimization, we find that different kinds of TTRs have big differences in some physical quantities. The present invention extracts these features (physical quantities) and classifies the selected TTRs into K categories based on their feature vectors through a weighted naive Bayesian classifier, which deeply digs the physical meanings contained in each TTR, makes the classification of TTRs more rational, and improves the accuracy of defect image's separation. Meanwhile, the multi-objective function does not only fully consider the similarities between the RTTR and other TTRs in the same category, but also considers the dissimilarities between the RTTR and the TTRs in other categories, thus the RTTR selected is more representative, which guarantees the accuracy of describing the defect outline. And the initial TTR population corresponding to the approximate solution for multi-objective optimization is chosen according to the previous TTR populations, which makes the multi-objective optimization dynamic and reduces its time consumption.

Method for separating out a defect image from a thermogram sequence based on weighted naive bayesian classifier and dynamic multi-objective optimization

The present invention provides a method for separating out a defect image from a thermogram sequence based on feature extraction and multi-objective optimization, we find that different kinds of TTRs have big differences in some physical quantities, such as the energy, temperature change rate during endothermic process, temperature change rate during endothermic process, average temperature, maximum temperature. The present invention extract these features (physical quantities) and cluster the selected TTRs into L clusters based on their feature vectors, which deeply digs the physical meanings contained in each TTR, makes the clustering more rational, and improves the accuracy of defect separation. Meanwhile, the present invention creates a multi-objective function to select a RTTR for each cluster based on multi-objective optimization. The multi-objective function does not only fully consider the similarities between the RTTR and other TTRs in the same cluster, but also considers the dissimilarities between the RTTR and the TTRs in other clusters, the RTTR is more representative, which guarantees the accuracy of describing the defect outline.

Method for separating out a defect image from a thermogram sequence based on feature extraction and multi-objective optimization

An apparatus for measuring temperature of turbine blades, including: a radiation collection device, a data processing module; a master control unit (MCU); a calibration module; and a motion servo. The radiation collection device includes a scan reflector, a collimator lens, a first dichroic mirror, a first focus lens, a visible and near-infrared (VNIR) detector, a second dichroic mirror, a second focus lens, a short-wave infrared (SWIR) detector, a third focus lens, and a medium-wave infrared (MWIR) detector. The calibration module includes a calibration reflection mirror and a blackbody furnace. The scan reflector, the collimator lens, the first dichroic mirror, the second dichroic mirror, the third focus lens, and the MWIR detector are disposed successively along a first optical axis; the first dichroic mirror, the first focus lens, and the VNIR detector are disposed successively along a second optical axis that is perpendicular to the first optical axis.

Apparatus for measuring temperature of aero-engine turbine blades

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

Yuhua Cheng