Eddy current array nondestructive testing system based on multi-excitation multi-receiving intelligent sensing control

Abstract

The invention discloses an eddy current array nondestructive testing system based on multi-excitation multi-reception intelligent sensing control, which is characterized in that a tested piece is placed below a multi-excitation multi-reception probe, and multiple paths of alternating excitation current generated by an excitation circuit are simultaneously introduced into a plurality of excitation coils to generate an electromagnetic field acting on the tested piece; magnetic flux in a tested piece changes along with alternating current, eddy current is generated on the surface and in the test piece, the eddy current can generate a secondary magnetic field to act on a plurality of receiving coils above the defective test piece, and induced voltage signals are generated in the receiving coils and are simultaneously acquired by a plurality of acquisition circuits; then the data is transmitted to a computer through a central controller to judge the shape of the defect, excitation parameters are adaptively adjusted, then the adjusted excitation parameters are issued to excitation coils of the multiple excitation circuits, and the excitation coils adaptively change an excitation electromagnetic field according to the initial shape of the defect; and finally, receiving a voltage signal of the coil, transmitting the voltage signal to a computer for feature extraction and processing, and finally determining the accurate shape of the defect.

Description

Technical Field

[0001] The present invention belongs to the technical field of nondestructive testing, and more specifically, relates to an eddy current array nondestructive testing system based on multi-excitation and multi-reception intelligent sensing control. Background Art

[0002] As the manufacturing industry develops towards higher technology levels and intelligence, the demand for complex and high-performance metal structural parts is increasing. These structural parts usually play an important role in key fields such as aerospace, automobile manufacturing and nuclear energy, and their performance and reliability directly affect the safety and efficiency of the system. Non-destructive testing technology can achieve non-contact measurement and has gradually become an efficient tool for ensuring the quality and reliability of high-performance components during production and service. Identifying and evaluating the health of components in the early stages of defect formation can help prevent potential major failures and ensure operational safety, thereby improving production efficiency and reducing economic losses.

[0003] In this context, non-destructive testing of metal structural parts is particularly important. As a non-contact testing technology, non-destructive testing can accurately detect internal or surface defects, such as cracks, corrosion or other discontinuities, without destroying materials or components. This plays an important role in ensuring product quality, extending equipment life, and preventing safety accidents. Among non-destructive testing technologies, eddy current array testing technology (ECA) can achieve rapid analysis and detection of defects on the surface or inside of the test object by virtue of the advantages of multi-probe arrays, and provide rich two-dimensional or multi-dimensional data sets during the detection process.

[0004] The traditional eddy current array detection method is generally to excite multiple receiving coils through one excitation coil. Although different defects can be scanned and imaged, it is difficult for the traditional eddy current array to abstract the entire system into a simple linear model in a complex time-varying environment. It can only passively receive data from the coil, rather than actively adjusting the excitation coil parameters to obtain richer defect detection information. Therefore, it is impossible to accurately quantify the shape of the defect. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide an eddy current array nondestructive testing system based on multi-excitation and multi-reception intelligent sensing control. By actively sensing the defect shape, for defects of different shapes, the excitation parameters of multiple excitation coils are actively adjusted to achieve active sensing of the defect shape, and according to the signal characteristics and change rules of the receiving coil, the defect position and shape can be accurately quantified.

[0006] To achieve the above-mentioned invention object, the present invention provides an eddy current array nondestructive testing system based on multi-excitation and multi-receiving intelligent sensing control, characterized in that it includes: a computer and an intelligent sensing control actuator; wherein the intelligent sensing control actuator includes: a central controller, an excitation circuit, a receiving circuit and a multi-excitation and multi-receiving probe;

[0007] The computer includes a set of intelligent sensing control reinforcement learning algorithms and defect detection algorithms that interact with real physical fields; the intelligent sensing control reinforcement learning algorithm randomly generates a set of N*N initial excitation parameters, and then sends the initial excitation parameters to the N*N digital-to-analog conversion chip of the central controller, converts the initial excitation parameters into excitation signals to act on the N*N excitation circuits, the N*N excitation circuits amplify the excitation signals and act on the N*N excitation coils, the electromagnetic field generated by the excitation coils acts on the test piece, thereby generating induced eddy currents at the defect location, the secondary magnetic field of the induced eddy currents acts in reverse on the N*N receiving coils, causing an initial induced voltage to appear on the receiving coils, the N*N receiving circuits attenuate the initial induced voltage signals, and then pass through the The N*N analog-to-digital conversion chip in the central controller converts the initial induced voltage into a digital signal and then uploads it to the computer; the computer calls the intelligent induction control reinforcement learning algorithm to analyze and process the initial induced voltage on the receiving coil, and adaptively updates the N*N new excitation parameters, and then repeats the above operation until the electromagnetic field generated by the excitation coil is focused near the defect position, so that the induced eddy current generated at the defect position is enhanced, and the secondary magnetic field generated by the induced eddy current is enhanced. The enhanced secondary magnetic field acts in the opposite direction on the N*N receiving coils. The iteration ends when the induced voltage on the N*N receiving coils is higher than the initial induced voltage. Then, the computer calls the defect detection algorithm to perform feature analysis and processing on the induced voltage to obtain the shape information of the defect;

[0008] The central controller comprises an FPGA chip, an N*N digital-to-analog conversion chip and an N*N analog-to-digital conversion chip, wherein the FPGA chip is used to configure the excitation parameters issued by the computer into the N*N digital-to-analog conversion chips, and each digital-to-analog conversion chip is configured with one excitation parameter; at the same time, the induced voltage signal on each receiving coil is received through the N*N digital-to-analog conversion chip, and the induced voltage signal is transmitted to the computer for feature analysis and processing;

[0009] The excitation circuit array comprises N*N independent excitation circuits, which are used to amplify the excitation signals converted by the N*N digital-to-analog conversion chips and then act on the N*N excitation coils;

[0010] Each independent excitation circuit is composed of two stages of amplifier circuits in cascade, the first stage of the amplifier circuit is used to amplify the excitation signal output by the digital-to-analog conversion chip, and the second stage of the amplifier circuit is used to perform voltage following on the output signal of the first stage of the amplifier circuit to obtain an alternating excitation current; each independent excitation circuit generates an independent alternating excitation current of different frequencies, amplitudes and phases according to the excitation parameters sent by the computer;

[0011] The receiving circuit array includes N*N independent receiving circuits for collecting voltage signals of receiving coils in a multi-excitation multi-receiving probe;

[0012] Each independent receiving circuit is composed of two-stage signal attenuation circuits in cascade, wherein the first-stage attenuation circuit attenuates the received signal, and the second-stage attenuation circuit is used to perform voltage following on the first-stage signal and convert the single-ended signal into a differential signal; finally, the N*N differential signals are input into the analog-to-digital conversion chip in the central controller;

[0013] The multi-excitation multi-receiving probe includes N*N excitation coils and N*N receiving coils. The N*N excitation coils are used to excite the test piece, thereby generating induced eddy currents at the defect position of the test piece; the N*N receiving coils are used to receive the secondary magnetic field generated by the induced eddy currents at the defect position, and generate an induced voltage in the receiving coil and upload it to a computer.

[0014] The object of the invention of the present invention is achieved in this way:

[0015] The present invention is based on a multi-excitation multi-receiving intelligent sensing control eddy current array nondestructive testing system. The test piece is placed under a multi-excitation multi-receiving probe. The 16-way alternating excitation current generated by the excitation circuit is simultaneously passed into 16 excitation coils. The electromagnetic field generated by the excitation coil directly acts on the test piece, so that the magnetic flux in the test piece changes with the alternating current, and eddy currents are generated on the surface and inside of the test piece. The eddy currents will generate secondary magnetic fields. The secondary magnetic fields act on the 16 receiving coils above the defective test piece, and an induced voltage signal is generated inside the receiving coil. The induced voltage signal is collected simultaneously by 16 acquisition circuits, and the voltage signal is transmitted to a computer through a central controller. The computer preliminarily determines the shape of the defect according to the voltage signal, and adjusts the excitation parameters adaptively. The central controller configures the excitation parameters issued by the computer through 16 excitation circuits and simultaneously configures them into the excitation coil. The excitation coil adaptively changes the excitation electromagnetic field according to the initial shape of the defect. Finally, the voltage signal of the receiving coil is transmitted to the computer for signal feature extraction and processing, so as to accurately quantify the shape of the defect, thereby achieving the purpose of nondestructive testing.

[0016] At the same time, the eddy current array nondestructive testing system based on multi-excitation and multi-reception intelligent sensing control of the present invention also has the following beneficial effects:

[0017] (1) The present invention adaptively changes the excitation parameters according to the different basic shapes of the defects under the excitation coil, focuses the generated electromagnetic field to the defect position, and improves the detection accuracy;

[0018] (2) The array of multiple excitation coils and multiple receiving coils used in the present invention can modulate the parameters of the excitation coil according to the defect shape, so that the electromagnetic field is focused near the defect, which can scan the defect more comprehensively and quickly;

[0019] (3) The excitation circuit and the detection circuit adopt parallel excitation and acquisition, and the voltage signals between the multiple detection coils will be coupled with each other, providing richer defect feature information, and can achieve rapid, effective and accurate quantitative detection and evaluation of defect shapes;

[0020] (4) The present invention adopts a set of intelligent sensor-controlled reinforcement learning algorithms that interact with real physical fields, and has the ability to regulate independent alternating excitation currents of different frequencies, amplitudes and phases in the excitation coil; by adaptively regulating the alternating excitation current in the excitation coil, after continuous iteration, the electromagnetic field generated by the excitation coil is focused on the defect position, the induced eddy current at the defect position is enhanced, and the secondary magnetic field generated by the induced eddy current at the defect position acts in the receiving coil in reverse, so that the induced voltage in the receiving coil is enhanced, thereby improving the sensitivity of defect detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural principle diagram of the eddy current array nondestructive testing system based on multi-excitation and multi-reception intelligent sensing control of the present invention;

[0022] Figure 2 It is a multi-excitation multi-receive probe.

[0023] Figure 3 It is the schematic diagram of the excitation circuit.

[0024] Figure 4 It is the schematic diagram of the acquisition circuit. DETAILED DESCRIPTION

[0025] The specific implementation of the present invention is described below in conjunction with the accompanying drawings so that those skilled in the art can better understand the present invention. It should be noted that in the following description, when the detailed description of known functions and designs may dilute the main content of the present invention, these descriptions will be omitted here.

[0026] Example

[0027] Figure 1 It is a structural principle diagram of the eddy current array nondestructive testing system based on multi-excitation and multi-reception intelligent sensing control of the present invention.

[0028] In this embodiment, if Figure 1 As shown, the present invention is an eddy current array nondestructive testing system based on multi-excitation and multi-receiving intelligent sensing control, including: a computer and an intelligent sensing control actuator; wherein the intelligent sensing control actuator includes: a central controller, an excitation circuit, a receiving circuit and a multi-excitation and multi-receiving probe;

[0029] The computer includes a set of intelligent sensing control reinforcement learning algorithms and defect detection algorithms that interact with real physical fields; the intelligent sensing control reinforcement learning algorithm randomly generates a set of 4*4 initial excitation parameters, and then sends the initial excitation parameters to the 4*4 digital-to-analog conversion chip of the central controller, converts the initial excitation parameters into excitation signals to act on the 4*4 excitation circuit, and the 4*4 excitation circuit amplifies the excitation signal and acts on the 4*4 excitation coil. The electromagnetic field generated by the excitation coil acts on the test piece, thereby generating induced eddy currents at the defect location, and the secondary magnetic field of the induced eddy current acts in the opposite direction on the 4*4 receiving coil, causing an initial induced voltage to appear on the receiving coil. The 4*4 receiving circuit attenuates the initial induced voltage signal and passes through the central The 4*4 analog-to-digital conversion chip in the central controller converts the initial induced voltage into a digital signal and then uploads it to the computer; the computer calls the intelligent induction control reinforcement learning algorithm to analyze and process the initial induced voltage on the receiving coil, and adaptively updates the 4*4 new excitation parameters, and then repeats the above operation until the electromagnetic field generated by the excitation coil is focused near the defect position, so that the induced eddy current generated at the defect position is enhanced, and the secondary magnetic field generated by the induced eddy current is enhanced. The enhanced secondary magnetic field acts in the opposite direction on the 4*4 receiving coil. The iteration ends when the induced voltage on the 4*4 receiving coil is higher than the initial induced voltage. Then, the computer calls the defect detection algorithm to perform feature analysis and processing on the induced voltage to obtain the shape information of the defect;

[0030] The central controller includes FPGA, 4*4-channel digital-to-analog conversion chips and 4*4-channel analog-to-digital conversion chips, where the FPGA model is AXU2CG, each digital-to-analog conversion chip model is AD9959, and each analog-to-digital conversion chip model is ADS6445;

[0031] FPGA is used to configure the excitation parameters sent by the computer into the 4*4 digital-to-analog conversion chips, and each digital-to-analog conversion chip is configured with one excitation parameter; at the same time, the induced voltage signal on each receiving coil is received through the 4*4 digital-to-analog conversion chip, and the induced voltage signal is transmitted to the computer for feature analysis and processing;

[0032] The excitation circuit array includes 4*4 independent excitation circuits, which are used to amplify the excitation signals converted by the 4*4 digital-to-analog conversion chips and then act on the 4*4 excitation coils;

[0033] Among them, each independent excitation circuit is composed of two-stage amplifier circuits in cascade, the first stage amplifier circuit is used to amplify the excitation signal output by the digital-to-analog conversion chip, and the second stage amplifier circuit is used to perform voltage following on the output signal of the first stage amplifier circuit to obtain an alternating excitation current; in this embodiment, 16 channels are excited simultaneously, so that each independent excitation circuit can generate an alternating excitation current with different frequencies, amplitudes and phases for each independent channel according to the excitation parameters sent by the computer;

[0034] The receiving circuit array includes 4*4 independent receiving circuits for collecting voltage signals of receiving coils in the multi-excitation multi-receiving probe;

[0035] Each independent receiving circuit is composed of two-stage signal attenuation circuits in cascade, wherein the first-stage attenuation circuit attenuates the received signal, and the second-stage attenuation circuit is used to perform voltage following on the first-stage signal and convert the single-ended signal into a differential signal; finally, the 4*4 differential signals are input into the analog-to-digital conversion chip in the central controller;

[0036] The multi-excitation multi-receiving probe includes 4*4 excitation coils and 4*4 receiving coils. The 4*4 excitation coils are used to excite the test piece, thereby generating induced eddy currents at the defect location of the test piece; the 4*4 receiving coils are used to receive the secondary magnetic field generated by the induced eddy currents at the defect location, and generate induced voltage in the receiving coils and upload it to the computer.

[0037] In this embodiment, if Figure 2 As shown, the multi-excitation multi-receiving probe includes 16 excitation coils and 16 receiving coils. The 16 excitation coils are located above the 16 receiving coils, and the lifting distance is set to 4 mm; the 16 receiving coils are located above the test piece, and the lifting distance is set to 1 mm; all the excitation coils and receiving coils are arranged in an array of 4 rows and 4 columns.

[0038] In this embodiment, if Figure 2 As shown in (a), a single excitation coil comprises 4 layers, each layer is composed of 17 turns of copper wire of a printed circuit board, and the whole is in a spiral shape; wherein, the width of the copper wire is 0.125 mm, the thickness is 0.035 mm, the distance between two adjacent turns of wire is 0.125 mm, the distance between the first and second layers is 0.21 mm, the distance between the second and third layers is 1.065 mm, the distance between the third and fourth layers is 0.21 mm, and adjacent layers are connected by copper-plated vias with a diameter of 0.2 mm;

[0039] In this embodiment, if Figure 2As shown in (b), a single receiving coil comprises 6 layers, each layer is composed of 21 turns of copper wire of a printed circuit board, and the whole is spiral-shaped; wherein, the width of the copper wire is 0.1 mm, the thickness is 0.035 mm, the distance between two adjacent turns of wire is 0.1 mm, the distance between the first and second layers is 0.2 mm, the distance between the second and third layers is 0.25 mm, the distance between the third and fourth layers is 0.51 mm, the distance between the fourth and fifth layers is 0.25 mm, the distance between the fifth and sixth layers is 0.2 mm, and adjacent layers are connected using 0.2 mm diameter copper-plated vias.

[0040] like Figure 3 The figure shows the excitation circuit. The central controller outputs the excitation parameters to the digital-to-analog conversion chip AD9959 in the excitation circuit. The AD9959 outputs an analog signal with a maximum peak-to-peak voltage of 1V to the operational amplifier chip AD8129. The operational amplifier chip amplifies the input voltage signal by 10 times and outputs an analog signal with a maximum peak-to-peak voltage of 10V to the power amplifier chip LT1210. The LT1210 will follow the input voltage signal and increase the output current to a maximum output of 1A. Finally, the output of LT1210 is connected to the excitation coil to excite the coil and generate an electromagnetic field. The output electromagnetic field signal is controlled by the excitation parameters. The output excitation acts on the defective specimen and can generate a maximum peak-to-peak voltage of 10V; a maximum sine wave frequency of 10MHz, a minimum step frequency of 1Hz; a maximum sine wave phase of 359 degrees, and a minimum step of 1 degree. Finally, the electromagnetic field signal acts on the defective specimen and generates eddy currents in the specimen.

[0041] like Figure 4 The figure shows the acquisition circuit. The secondary magnetic field generated by the eddy current in the test piece acts on the receiving coil, generating an induced voltage in the receiving coil. The induced voltage is reduced by 5 times by the operational amplifier chip AD8055, and then sent to the single-ended to differential operational amplifier chip AD8138, which converts the single-ended voltage signal into a differential signal. Finally, it is acquired by the analog-to-digital conversion chip ADS6445, converted into a 14-bit acquisition voltage signal, and transmitted to the central controller.

[0042] Although the above describes the illustrative specific embodiments of the present invention to facilitate those skilled in the art to understand the present invention, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art, as long as various changes are within the spirit and scope of the present invention as defined and determined by the attached claims, these changes are obvious, and all inventions and creations using the concept of the present invention are protected.

Claims

1. An eddy current array nondestructive testing system based on multi-excitation and multi-reception intelligent sensing control, characterized in that: include: Computer and intelligent sensor control actuator; wherein the intelligent sensor control actuator includes: a central controller, an excitation circuit, a receiving circuit and a multi-excitation and multi-receiving probe; The computer includes a set of intelligent sensing control reinforcement learning algorithms and defect detection algorithms that interact with real physical fields; the intelligent sensing control reinforcement learning algorithm randomly generates a set of N*N initial excitation parameters, and then sends the initial excitation parameters to the N*N digital-to-analog conversion chip of the central controller, converts the initial excitation parameters into excitation signals to act on the N*N excitation circuits, the N*N excitation circuits amplify the excitation signals and act on the N*N excitation coils, the electromagnetic field generated by the excitation coils acts on the test piece, thereby generating induced eddy currents at the defect location, the secondary magnetic field of the induced eddy currents acts in reverse on the N*N receiving coils, causing an initial induced voltage to appear on the receiving coils, the N*N receiving circuits attenuate the initial induced voltage signals, and then pass through the The N*N analog-to-digital conversion chip in the central controller converts the initial induced voltage into a digital signal and then uploads it to the computer; the computer calls the intelligent induction control reinforcement learning algorithm to analyze and process the initial induced voltage on the receiving coil, and adaptively updates the N*N new excitation parameters, and then repeats the above operation until the electromagnetic field generated by the excitation coil is focused near the defect position, so that the induced eddy current generated at the defect position is enhanced, and the secondary magnetic field generated by the induced eddy current is enhanced. The enhanced secondary magnetic field acts in the opposite direction on the N*N receiving coils. The iteration ends when the induced voltage on the N*N receiving coils is higher than the initial induced voltage. Then, the computer calls the defect detection algorithm to perform feature analysis and processing on the induced voltage to obtain the shape information of the defect; The central controller includes an FPGA, an N*N digital-to-analog conversion chip and an N*N analog-to-digital conversion chip, wherein the FPGA is used to configure the excitation parameters issued by the computer into the N*N digital-to-analog conversion chips, and each digital-to-analog conversion chip is configured with one excitation parameter; at the same time, the induced voltage signal on each receiving coil is received through the N*N digital-to-analog conversion chip, and the induced voltage signal is transmitted to the computer for feature analysis and processing; The excitation circuit array comprises N*N independent excitation circuits, which are used to amplify the excitation signals converted by the N*N digital-to-analog conversion chips and then act on the N*N excitation coils; Each independent excitation circuit is composed of two stages of amplifier circuits in cascade, the first stage of the amplifier circuit is used to amplify the excitation signal output by the digital-to-analog conversion chip, and the second stage of the amplifier circuit is used to perform voltage following on the output signal of the first stage of the amplifier circuit to obtain an alternating excitation current; each independent excitation circuit generates an independent alternating excitation current of different frequencies, amplitudes and phases according to the excitation parameters sent by the computer; The receiving circuit array includes N*N independent receiving circuits for collecting voltage signals of receiving coils in a multi-excitation multi-receiving probe; Each independent receiving circuit is composed of two-stage signal attenuation circuits in cascade, wherein the first-stage attenuation circuit attenuates the received signal, and the second-stage attenuation circuit is used to perform voltage following on the first-stage signal and convert the single-ended signal into a differential signal; finally, the N*N differential signals are input into the analog-to-digital conversion chip in the central controller; The multi-excitation multi-receiving probe includes N*N excitation coils and N*N receiving coils. The N*N excitation coils are used to excite the test piece, thereby generating induced eddy currents at the defect position of the test piece; the N*N receiving coils are used to receive the secondary magnetic field generated by the induced eddy currents at the defect position, and generate an induced voltage in the receiving coil and upload it to a computer.

2. The eddy current array nondestructive testing system based on multi-excitation and multi-reception intelligent sensing control according to claim 1 is characterized in that: The multi-excitation multi-receiving probe includes 16 excitation coils and 16 receiving coils, the 16 excitation coils are located above the 16 receiving coils, and the 16 receiving coils are located above the test piece, and all the excitation coils and receiving coils are arranged in an array of 4 rows and 4 columns.

3. The eddy current array nondestructive testing system based on multi-excitation and multi-reception intelligent sensing control according to claim 2 is characterized in that: The single excitation coil comprises 4 layers, each layer is composed of 17 turns of copper wire of a printed circuit board, and the whole is spiral; wherein, the width of the copper wire is 0.125mm, the thickness is 0.035mm, the distance between two adjacent turns of wire is 0.125mm, the distance between the first and second layers is 0.21mm, the distance between the second and third layers is 1.065mm, the distance between the third and fourth layers is 0.21mm, and adjacent layers are connected using copper-plated vias with a diameter of 0.2mm.

4. The eddy current array nondestructive testing system based on multi-excitation and multi-reception intelligent sensing control according to claim 2 is characterized in that: The single receiving coil comprises 6 layers, each layer is composed of 21 turns of copper wire of a printed circuit board, and the whole is spiral; wherein, the width of the copper wire is 0.1 mm, the thickness is 0.035 mm, the distance between two adjacent turns of wire is 0.1 mm, the distance between the first layer and the second layer is 0.2 mm, the distance between the second layer and the third layer is 0.25 mm, the distance between the third layer and the fourth layer is 0.51 mm, the distance between the fourth layer and the fifth layer is 0.25 mm, the distance between the fifth layer and the sixth layer is 0.2 mm, and adjacent layers are connected using copper-plated vias with a diameter of 0.2 mm.

5. The eddy current array nondestructive testing system based on multi-excitation and multi-reception intelligent sensing control according to claim 2 is characterized in that: The lifting distance between the excitation coil and the receiving coil is set to 4 mm, and the lifting distance between the receiving coil and the test piece is set to 1 mm.

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