Abstract: 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.

Abstract: 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.

Abstract: A random transient power test signal generator based on three-dimensional memristive discrete map, which utilizes a three-dimensional parallel bi-memristor Logistic map module to generate two pseudo-random sequences, and based on the sequences, uses two waveform output modules to generate transient voltage and transient current signals respectively, thus the random transient power testing signal is obtained. The map can significantly improve the complexity of chaos and greatly extend its range of chaos. In addition, a performance evaluation shows the map has more robust hyperchaotic behavior in much larger chaos range. Moreover, the random sequences generated by the map module combines with DDS, which can generate a transient power signal with completely random period, starting phase and ending phase.

Abstract: A circuit and method for simulating real-time reconfigurable general-purpose memristor, nonlinear m-order polynomial fitting of mathematical model of a memristor is performed by using McLaughlin formula. m is related to the amplitude and frequency of an input signal and the fitting accuracy, thus the mathematical model of a memristor can be easily and quickly adapted by updating the polynomial order, the polynomial coefficients and the FPGA system clock cycle. Based on the FPGA, a system state variable generation module, a FIFO, a output module are used to obtain an output signal y[n]. the detailed steps of signal processing and displaying are given to obtain a display of a pinched hysteresis loop and a waveform display of time-domain. Simulation of high frequency memristor by setting polynomial coefficients can be obtained. Meanwhile, this is built based on FPGA, adopt digital circuit to simulates a reconfigurable general-purpose memristor, and experimental accuracy is enhanced.

Abstract: 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.

Abstract: 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.

Abstract: 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×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.

Abstract: 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×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.

Abstract: 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.

Abstract: 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.