A teaching aid for magnetic flux leakage detection based on LabVIEW

Abstract

The present invention discloses a teaching device for magnetic flux leakage detection based on LabVIEW, which includes a lead wire wound around a ferrite, and both ends of the lead wire are connected to the positive and negative poles of a battery, respectively; the ferrite, the AMR sensor and the displacement sensor are all placed on the upper end of the detection object; the AMR sensor and the displacement sensor are electrically connected to a circuit board; the 3X3 AMR sensor array forms a probe; the circuit board is placed on a display stand; an external power supply supplies power to the circuit board; a host computer compiles and provides a program to the circuit board; the host computer is externally connected to a teaching screen; As shown in the enlarged view above, this device is small in volume, easy to assemble and carry, and convenient in detection operation. It intuitively shows the detection process of the damaged part of the detection object, and the detection process is transmitted to and displayed on the classroom teaching screen in real time. Compared with other traditional software, LabVIEW can use general-purpose hardware, so it is more convenient in terms of hardware procurement and more suitable for the needs of teaching tools compared to other matching software that requires corresponding customized hardware, and fills the gap in educational demonstration teaching tools in the field of magnetic flux leakage detection.

Description

[Technical field]

[0001] The present invention relates to the technical field of teaching equipment, and in particular to a teaching equipment device for magnetic flux leakage detection based on LabVIEW. [Background technology]

[0002] Magnetic flux leakage detection technology has a long history of research and use. The predecessor of magnetic flux leakage technology is the conventional magnetic particle inspection method. The origin of magnetic flux leakage detection technology dates back to the 1870s, when Maxwell inherited the ideas of Faraday, integrated the research of Coulomb, Ampere and others, and proposed Maxwell's electromagnetic equations. The conventional magnetic particle inspection method was proposed in 1922, and magnetic particle inspection was realized eight years later. The first magnetic flux leakage detection device in the true sense was designed and completed by Hastings in the 1940s.

[0003] Research on magnetic flux leakage detection theory began in 1966. Soviet scientists Zastsepin and Scherbinin established the magnetic charge model theory, which is one of the important theoretical foundations of magnetic flux leakage detection method, based on the magnetic dipole theory of rectangular cracks of indefinite length to explain the magnetic flux leakage phenomenon. Another research method of magnetic flux leakage detection, the finite element analysis method, has been widely used in the field of magnetic flux leakage detection since the birth of Swanson J's ANSYS finite element analysis software in 1970. Five years later, Hwang and Lord linked the internal magnetic field and permeability with the leakage magnetic field through the finite element analysis method, and analyzed and calculated the spatial distribution of the leakage magnetic field. Atherton further studied the relationship between defects and the distribution of the leakage magnetic field strength. Li.Y and Tian GY studied the situation of magnetic flux leakage detection system under high-speed motion.

[0004] Traditional magnetic flux leakage detection devices are mainly used in oil and gas pipelines, subsea pipelines, storage tank floors, steel ropes and pressure vessels. Due to the requirement of ensuring safety in the industrial and infrastructure construction fields and the increasing safety awareness of people, the demand for magnetic flux leakage detection technology is increasing. However, when teaching the principle of magnetic flux leakage detection, it is not possible to demonstrate it well to students, and only written explanations are possible. As a result, the principle cannot be intuitively understood by students. The magnetic flux leakage detection devices are too large, have a complex configuration, the detection procedures are complicated, and multiple components need to be coordinated. Therefore, there are currently no demonstration teaching tools on the market that meet the educational needs of magnetic flux leakage detection technology. Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention provides a teaching device for magnetic flux leakage detection based on LabVIEW to solve the problem that, in the past, demonstration teaching tools that meet the educational needs of magnetic flux leakage detection technology are not currently available on the market because conventional magnetic flux leakage detection devices are too large, have complex configurations, have complicated detection procedures, and require the coordination of multiple components.

[0006] To achieve the above objectives, the present invention uses the following technical solutions:

[0007] A teaching device for magnetic flux leakage detection based on LabVIEW includes a lead wire wound around a ferrite, both ends of which are connected to the positive and negative poles of a battery, the ferrite, an AMR sensor and a displacement sensor are all placed on the upper end of an object to be detected, the AMR sensor and the displacement sensor are electrically connected to a circuit board, the 3X3 AMR sensor array forms a probe, the circuit board is placed on a display stand, an external power supply supplies power to the circuit board, a host computer compiles and provides a program to the circuit board, and the host computer is externally connected to a teaching screen and enlarged and displayed thereon.

[0008] In a teaching device for magnetic flux leakage detection based on LabVIEW, the circuit board includes a data collection card, an amplifier circuit, a power supply circuit, and a setting circuit, the data collection card is electrically connected to the amplifier circuit and the power supply circuit, the external power supply supplies power to the data collection card by electrically connecting to the power supply circuit, the AMR sensor and the displacement sensor are electrically connected to the setting circuit, and the setting circuit is electrically connected to the amplifier circuit, the upper computer is connected to an external port provided on the data collection card via a general-purpose serial bus, and compiles a higher-level computer program into the data collection card.

[0009] In a teaching device for magnetic flux leakage detection based on LabVIEW, the upper computer program includes a continuous sampling module electrically connected to the amplification circuit, the continuous sampling module sends the collected analog signal to an AD conversion module, and the digital signal converted by the AD conversion module sends to a frequency modulation module, the frequency modulation module sends the modulated signal to a noise removal module, the noise removal module sends the noise-removed signal to a signal division module, the signal division module sends the divided signal to a data display module, and the data display module converts the signal into graphics and sends it to the teaching screen for display.

[0010] In the teaching aid device for magnetic flux leakage detection based on LabVIEW, the ferrite has an inverted concave shape, the two support arms of the ferrite contact the upper surface of the detection object, and the lead wires are wound around the ferrite at equal distances.

[0011] The present invention provides a teaching aid device for magnetic flux leakage detection based on LabVIEW, which has the following advantages and beneficial effects: the present invention has a small volume, is easy to assemble and carry, and is convenient to operate, intuitively shows the detection process of the damaged part of the detection object, and transmits and displays the detection process to the classroom teaching screen in real time; compared with other traditional software, labview can use general-purpose hardware, so that it is more convenient in terms of hardware procurement and more suitable for the needs of teaching aids compared with other matching software that requires corresponding customized hardware, and fills the gap of educational demonstration teaching aids in the field of magnetic flux leakage detection. [Brief description of the drawings]

[0012] [Figure 1] 1 is a structural schematic diagram of a teaching device for magnetic flux leakage detection based on LabVIEW according to the present invention; [Diagram 2] FIG. 2 is a block diagram of a circuit board of a teaching device for magnetic flux leakage detection based on LabVIEW according to the present invention. [Diagram 3] FIG. 2 is a block diagram of a higher-level computer program of the teaching device for magnetic flux leakage detection based on LabVIEW according to the present invention. [Figure 4] FIG. 1 is a circuit diagram of an AMR sensor for magnetic flux leakage detection teaching aid device based on LabVIEW according to the present invention. [Diagram 5] FIG. 1 is a diagram of a configuration circuit of a teaching device for magnetic flux leakage detection based on LabVIEW according to the present invention. [Figure 6] FIG. 1 is a system block diagram of a data acquisition card of a teaching aid device for magnetic flux leakage detection based on LabVIEW according to the present invention. [Figure 7] FIG. 1 is a wiring diagram of a continuous sampling module of a teaching aid for magnetic flux leakage detection based on LabVIEW according to the present invention. [Figure 8] FIG. 1 is a wiring diagram of a data display module of a teaching device for magnetic flux leakage detection based on LabVIEW according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The invention will now be described in detail with reference to the drawings and specific embodiments.

[0014] As shown in Figures 1 to 8, the teaching device for magnetic flux leakage detection based on LabVIEW according to this embodiment includes a lead wire 2 wound around a ferrite 1, both ends of which are connected to the positive and negative poles of a battery 3, respectively; the ferrite 1 has an inverted concave shape; when the two support arms 11 of the ferrite 1 come into contact with the surface of the upper end of the detection target 6, they form an excitation element; the effect of magnetization is also related to the resolution and signal-to-noise ratio of the magnetic field signal converted from the defect; the ferrite 1 is a non-metallic magnetic material, whose resistivity is 1,000 times that of metal and whose magnetic permeability reaches several thousand times at high frequencies, making it suitable for high-frequency eddy current detection; when the detection target 6 is in a saturated state or close to saturation, the defective part of the target generates a leakage magnetic field signal sufficient to be captured by the probe in the signal detection system.

[0015] The ferrite 1, the AMR sensor 4 and the displacement sensor 5 are all placed on the top of the detection object 6, the AMR sensor 4 is used to detect the leakage magnetic field of the detection object, the 3X3 AMR sensor 4 array forms a probe 13, its model number is HMC1021, which has a wider range, lower power consumption, smaller size and lower cost, the setting characteristics of the AMR sensor 4 can make it work in a high sensitivity state, and can also reduce the influence of various factors such as temperature and vertical axis, the displacement sensor 5 detects the displacement of the object, so that the length of the crack can be more clearly displayed in three axes of X, Y and Z, and furthermore, the software can show the waveform and display a three-dimensional model of the waveform.

[0016] The AMR sensor 4 and the displacement sensor 5 are electrically connected to a circuit board 7, and the circuit board 7 is placed on a display stand 12, which holds the circuit board 7 upright so that the layout of the circuit board 7 can be easily observed, an external power source 8 supplies power to the circuit board 7, and a host computer 9 compiles and provides a program to the circuit board 7, and the host computer 9 is externally connected to a teaching screen 10 and is displayed enlarged thereon.

[0017] The circuit board 7 includes a data collection card 71, an amplifier circuit 72, a power circuit 73, and a setting circuit 74. The data collection card 71 is electrically connected to the amplifier circuit 72 and the power circuit 73. The external power supply 8 is electrically connected to the power circuit 73 to power the data collection card 71. The AMR sensor 4 and the displacement sensor 5 are electrically connected to the setting circuit 74. The setting circuit 74 is electrically connected to the amplifier circuit 72. The upper computer 9 is connected to an external port provided on the data collection card 71 via a general-purpose serial bus and compiles the upper computer program 90 into the data collection card 71. The operating principle of the setting circuit 74 is to convert a short-term large current into an S / R current of the chip. The main function of the setting circuit 74 is to adjust the AMR sensor 4 and the displacement sensor 5 to a good working state so that the sensitivity of the AMR sensor 4 and the displacement sensor 5 can be fully exerted.

[0018] The model number of the data collection card 71 is USB3100, which performs the required analog-to-digital conversion and provides hardware support for each module by interacting with the computer, and the analog input section of the USB3100 mainly consists of an AI terminal, a MUX data selector, a PGIA programmable gain amplifier, a low-pass filter, an analog-to-digital converter, an AI buffer, an analog trigger device, etc. The difference between this system and ordinary magnetic flux leakage is that this system captures the magnetic flux leakage signal of the ferromagnetic body using a group of four arrays of AMR sensors, processes the signal through a hardware circuit, and then controls and collects the data collection card 71 through LabVIEW software to complete the final waveform display.

[0019] The upper computer program 90 includes a continuous sampling module 91 electrically connected to the amplifier circuit 72, and the continuous sampling is performed in real time, which actually means that after starting up, the AI ​​continuously and constantly samples the defects of the ferromagnetic material according to the initially set sampling frequency and channel scan mode, that is, in the sampling process, the sampled continuous data is read in real time. In the implementation process, it is necessary to use many functions in the dynamic link library (DLL) provided with the LabVIEW program.

[0020] The continuous sampling module 91 sends the collected analog signal to the AD conversion module 92, and the digital signal converted by the AD conversion module 92 is sent to the frequency modulation module 93, which sends the modulated signal to the noise removal module 94, which sends the noise removed signal to the signal division module 95, which sends the divided signal to the data display module 96, and the output magnitude of the parameter output terminal determines the voltage value collected by the continuous sampling module, which mainly plays the role of a buffer, and what is stored therein is voltage data, the unit of which is volt-amperes (V), and the data type is double-precision floating-point type. Each data point of each channel interacts like a dog's teeth, and the opened point space is often larger than the parameter value of nSizePoint. The data display module 96 converts the signal into graphics and sends it to the teaching screen 10 for display.

[0021] The above describes the present invention and its embodiments, but the description does not limit the present invention, and the illustrated one is only an example of the embodiment of the present invention, and the actual structure is not limited thereto. In short, if a person skilled in the art does not deviate from the inventive purpose of the present invention, but creatively designs the same structural aspects and embodiments as the technical solutions, and takes inspiration from them, all of them shall belong to the protection scope of the present invention.

[0022] In describing the present invention, as necessary for explanation, orientations or positional relationships indicated by terms such as "upper", "lower", "inner", "outer", "front", "rear", "side", etc. are based on the orientations or positional relationships shown in the accompanying drawings and are used only to explain and simplify the description of the present invention, and do not indicate or imply that the devices or elements referred to have a particular orientation and must be constructed and operated in a particular direction, and therefore, they should not be construed as limitations on the present invention. [Explanation of symbols]

[0023] Explanation of drawing symbols 1. Ferrite, 2. Lead wire, 3. Battery, 4. AMR sensor, 5. Displacement sensor, 6. Detection object, 7. Circuit board, 8. External power supply, 9. Host computer, 10. Teaching screen, 11. Support arm, 12. Display stand, 71. Data acquisition card, 72. Amplification circuit, 73. Power supply circuit, 74. Setting circuit, 90. Host computer program, 91. Continuous sampling module, 92. AD conversion module, 93. Frequency modulation module, 94. Noise elimination module, 95. Signal division module, 96. Data display module.

Claims

1. A teaching device for magnetic flux leakage detection based on LabVIEW, comprising a lead wire (2) wound around a ferrite (1), both ends of the lead wire (2) being connected to the positive and negative poles of a battery (3), the ferrite (1), an AMR sensor (4) and a displacement sensor (5) all being placed on the upper end of a detection target (6), the AMR sensor (4) and the displacement sensor (5) being electrically connected to a circuit board (7), a 3x3 array of the AMR sensor (4) forming a probe (13), the circuit board (7) being placed on a display stand (12), an external power source (8) supplying power to the circuit board (7), a host computer (9) compiling and providing a program to the circuit board (7), the host computer (9) being externally connected to a teaching screen (10), The circuit board (7) includes a data collection card (71), an amplifier circuit (72), a power supply circuit (73), and a setting circuit (74), the data collection card (71) is electrically connected to the amplifier circuit (72) and the power supply circuit (73), the external power supply (8) is electrically connected to the power supply circuit (73) to supply power to the data collection card (71), the AMR sensor (4) and the displacement sensor (5) are electrically connected to the setting circuit (74), and the setting circuit (74) is electrically connected to the amplifier circuit (72), the host computer (9) is connected to an external port provided on the data collection card (71) via a general-purpose serial bus, and compiles a host computer program (90) into the data collection card (71), the host computer (9) includes a continuous sampling module (91) electrically connected to the amplifier circuit (72), the continuous sampling module (91) transmits collected analog signals to an AD conversion module (92), and transmits the digital signals converted by the AD conversion module (92) to a frequency modulation module (93), the frequency modulation module (93) transmits the modulated signals to a noise removal module (94), the noise removal module (94) transmits the noise-removed signals to a signal division module (95), the signal division module (95) transmits the divided signals to a data display module (96), and the data display module (96) converts the signals into graphics and transmits them to the teaching screen (10) for display.

2. The teaching aid for magnetic flux leakage detection based on LabView according to claim 1, characterized in that the ferrite (1) has an inverted concave shape, two support arms (11) of the ferrite (1) contact the upper surface of the detection target (6), and the lead wires (2) are wound around the ferrite (1) at equal distances.

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