Method and system for measuring magnetic field intensity, computer equipment and storage medium

Abstract

The invention relates to the technical field of magnetic field detection, and discloses a method and system for measuring magnetic field intensity, a computer program, equipment and a storage medium, and the method comprises the steps: setting a simple pendulum device for measuring the magnetic field intensity in a to-be-measured region; measuring the maximum swing angle of each period in the swing process of the simple pendulum device by using an angle sensor, and obtaining a magnetic field generation damping coefficient by using a computer program algorithm and data processing; and calculating the magnetic field intensity by using the damping coefficient and a preset eddy current damping model function. The magnetic field intensity is measured by using the eddy current damping effect generated by the simple pendulum motion in the magnetic field, the cost of magnetic field measurement can be reduced, and the operation complexity of magnetic field measurement is simplified.

Description

Technical Field

[0001] The present application relates to the field of magnetic field detection technology, and in particular to a method, system, computer program, device and storage medium for measuring magnetic field strength by utilizing the eddy current damping effect generated by a simple pendulum motion in a magnetic field. Background Art

[0002] Magnetic field measurement is extremely important in scientific research, medical testing, environmental monitoring, navigation and industrial applications. Accurately measuring magnetic field strength can optimize the performance of electronic equipment, ensure accurate navigation and positioning, monitor electromagnetic radiation safety, and warn of geological disasters.

[0003] Traditional magnetic field measurement methods include Hall elements and sodium lamps. Although they have been widely used, they have shown some limitations in weak magnetic field environments. Hall elements are extremely susceptible to electromagnetic noise interference when measuring weak magnetic field signals; Hall elements are easily affected by temperature changes and produce temperature drift; Hall elements are very sensitive to the amplitude and direction of the magnetic field, and may require precise calibration and configuration; due to sensitivity limitations, the measurement accuracy of Hall elements is not high enough. Sodium lamp measurement requires precise optical instruments and detection equipment, making the construction and maintenance of the entire system relatively complicated and the equipment cost high; environmental factors, such as strong light background or bad weather conditions, may affect the accuracy and stability of the measurement. In addition, there are other methods or instruments for measuring magnetic fields, such as magnetoresistance effect method, fluxgate magnetometer, atomic magnetometer, etc., most of which are expensive, complex equipment, and sensitive to environmental conditions. Summary of the invention

[0004] Based on this, it is necessary to propose a method, system, computer program, equipment and storage medium for measuring magnetic field strength by utilizing the eddy current damping effect generated by a simple pendulum motion in a magnetic field, in order to address the technical problems of high cost and complex operation of magnetic field measurement in the prior art, so as to reduce the cost of magnetic field measurement and simplify the operational complexity of magnetic field measurement.

[0005] A first aspect of the present application provides a method for measuring magnetic field strength, the method comprising:

[0006] A simple pendulum device for measuring the magnetic field strength is arranged in the area to be measured;

[0007] Using an angle sensor to measure the maximum swing angle of each cycle during the swinging process of the simple pendulum device;

[0008] The computer program algorithm is used to process the data to obtain the damping coefficient generated by the magnetic field, and the magnetic field strength is calculated using the damping coefficient and the preset eddy current damping model function.

[0009] Optionally, the data processing device calculates the damping coefficient according to the maximum swing angle using the following formula:

[0010] β 磁 =β-(β 空 +β 机 ),

[0011] in, where θ i ,θ i+6 are the maximum swing angles of the ith and i+6th cycles after the swing, respectively. 空 is the damping coefficient of air resistance, β 机 is the damping coefficient of mechanical resistance. The sum of the damping coefficient of air resistance and the damping coefficient of mechanical resistance is measured through a set of simple pendulum experiments without magnetic field.

[0012] Optionally, the function model is:

[0013]

[0014] Among them, S is the projection area of ​​the magnetic field on the pendulum, t is the thickness of the pendulum, B is the magnetic induction intensity, m is the mass of the pendulum, and ρ is the resistivity of the pendulum.

[0015] Optionally, the method further includes:

[0016] The effectiveness of the eddy current damping model is verified through a single pendulum experiment.

[0017] Optionally, verifying the effectiveness of the eddy current damping model through a single pendulum experiment includes:

[0018] A single pendulum device is provided in which the pendulum body is a copper sheet;

[0019] The copper pendulum is placed in the experimental magnetic field of the electromagnet gap;

[0020] An angle sensor is installed near the copper pendulum;

[0021] The copper pendulum is released from a small-angle (less than 5 degrees) swinging position, and the angle sensor is used to measure and record the maximum swing angle of each cycle during the swinging process.

[0022] The damping coefficient is calculated using the maximum swing angle data, and the experimental magnetic field strength is calculated based on the damping coefficient and a calibrated preset eddy current damping model function;

[0023] Use a magnetic field measuring device to measure the real magnetic field strength;

[0024] The experimental magnetic field strength is verified according to the real magnetic field strength.

[0025] Optionally, the simple pendulum device includes a pendulum body made of a conductive material and a fixed fulcrum for suspending the pendulum body.

[0026] A second aspect of the present application provides a system for measuring magnetic field strength, the system comprising:

[0027] Single pendulum device;

[0028] An angle sensor, used to measure the maximum swing angle of each cycle during the swinging process of the pendulum of the simple pendulum device;

[0029] A data processing device is used to obtain the maximum swing angle measured by the angle sensor, calculate the damping coefficient according to the maximum swing angle, and calculate the magnetic field strength according to the damping coefficient and a preset eddy current damping model function.

[0030] A third aspect of the present application provides a computer device, the computer device comprising:

[0031] a memory storing a computer program;

[0032] The processor implements the following steps when executing the computer program:

[0033] Store and read angle sensor data, and obtain the maximum swing angle through the peak-finding algorithm program;

[0034] Calculating a damping coefficient according to the maximum swing angle;

[0035] The magnetic field strength is calculated based on the damping coefficient and a preset eddy current damping model function.

[0036] A fourth aspect of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the following steps are implemented:

[0037] Store and record angle sensor data and maximum swing angle;

[0038] Calculating a damping coefficient according to the maximum swing angle;

[0039] The magnetic field strength is calculated based on the damping coefficient and a preset eddy current damping model function.

[0040] A fifth aspect of the present application provides a program for obtaining magnetic field strength by data processing and calculation, characterized in that the computer program comprises:

[0041] Read the angle sensor data and obtain the maximum swing angle through the peak-finding algorithm program;

[0042] The damping coefficient is calculated using the maximum swing angle;

[0043] The magnetic field strength is calculated based on the damping coefficient and a preset eddy current damping model function, and the magnetic field strength is displayed in real time.

[0044] The present application is based on simple mechanical principles and utilizes eddy current effect and damping effect to set up a simple pendulum device for measuring magnetic field strength in the area to be measured. The simple pendulum device has a simple structure, low cost, and easy operation. It does not require complex electronic circuits or optical equipment and has no electromagnetic interference with the magnetic field to be measured. The device can ensure the accurate position of the magnetic field measurement and avoid measurement errors caused by position offset. The device accurately measures changes in weak magnetic fields through amplitude attenuation curves, and can achieve high-precision measurements, especially when the experimental conditions are properly controlled.

[0045] The angle sensor is used to measure the maximum swing angle of each cycle during the swing process of the simple pendulum device, providing a reliable data basis for the subsequent calculation of the damping coefficient. The damping coefficient is calculated according to the maximum swing angle using a data processing device, and the magnetic field strength is calculated according to the damping coefficient and the preset eddy current damping model function (the function model between the damping coefficient and the magnetic field strength). Based on theoretical derivation and experimental verification, the damping coefficient is converted into the magnetic field strength, which is highly scientific and accurate. The eddy current damping model is suitable for measurements in a variety of magnetic field environments, which improves the versatility and practicality of the measurement method and has high measurement accuracy. At the same time, the device has a simple structure and is easy to maintain, which is particularly suitable for teaching and laboratory research environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0047] in:

[0048] Figure 1 is a flow chart of a method for measuring magnetic field strength in one embodiment;

[0049] Figure 2 A schematic diagram of a scenario for measuring magnetic field strength in one embodiment;

[0050] Figure 3 A schematic diagram of a simple pendulum subjected to force in one embodiment;

[0051] Figure 4 A schematic diagram of the relationship between the swing period and the swing angle of a simple pendulum in one embodiment;

[0052] Figure 5is a flow chart of a method for verifying the validity of an eddy current damping model in one embodiment;

[0053] Figure 6 is a schematic diagram of the corresponding relationship between the damping coefficient and the real magnetic field strength in one embodiment;

[0054] Figure 7 is a schematic diagram of a β-B curve fitted in one embodiment;

[0055] Figure 8 A schematic diagram of using Comsol simulation software to simulate eddy current distribution in one embodiment;

[0056] Fig. 9 A schematic diagram of the structure of a system for measuring magnetic field strength in one embodiment;

[0057] Fig.10 FIG. 1 is a schematic diagram of the structure of a computer device in an embodiment. DETAILED DESCRIPTION

[0058] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0059] See also Figure 1 As shown, Figure 1 A flow chart of a method for measuring magnetic field strength provided in an embodiment of the present application, wherein the method for measuring magnetic field strength comprises the following steps.

[0060] S11, setting a simple pendulum device for measuring the magnetic field strength in the area to be measured.

[0061] like Figure 2 As shown, a simple pendulum device is arranged in the area to be measured, and the magnetic field strength in the area to be measured is measured by using the motion characteristics of the simple pendulum.

[0062] The pendulum device may include: a pendulum body, a cycloid and a fixed fulcrum. The pendulum body is a pendulum ball or a pendulum piece made of conductive material, which is suspended on the fixed fulcrum by the cycloid. The cycloid is a light and non-stretchable thin wire or thin rod to ensure that the fixed fulcrum is stable and vertical, so as to reduce interference with the movement of the pendulum.

[0063] It should be understood that in order to accurately measure the magnetic field strength in the area to be measured, it is necessary to ensure that the pendulum can swing freely and will not be interfered by other non-magnetic field factors.

[0064] S12, using an angle sensor to measure the maximum swing angle of each cycle during the swinging process of the simple pendulum device.

[0065] A high-precision angle sensor is installed at an appropriate position, for example, near the center or center of mass of the pendulum, to ensure that the measured angle can accurately reflect the overall swing of the pendulum.

[0066] After the angle sensor is installed, calibrate and test the angle sensor to ensure the accuracy and stability of the measurement results. You can use a reference angle sensor to measure the angle of the pendulum at different angles, use the angle measured by the reference angle sensor as the reference angle, and the angle measured by the angle sensor as the measurement angle. Use the reference angle to calibrate the angle sensor so that the angle sensor's measurement angle at different angles is consistent with the reference angle.

[0067] Start the pendulum device, use the angle sensor to measure and record the angle data of the pendulum during its swing, including the maximum swing angle of each cycle. The maximum swing angle refers to the angle corresponding to the maximum distance that the pendulum deviates from the equilibrium position.

[0068] S13, using a data processing device to calculate a damping coefficient according to the maximum swing angle, and to calculate a magnetic field strength according to the damping coefficient and a preset eddy current damping model.

[0069] The output of the angle sensor is connected to the data processing device, which can be connected wirelessly or wired. In this way, the data processing device can obtain the angle data measured by the angle sensor in real time. The data processing device calculates the damping coefficient based on the maximum swing angle, and then calculates the magnetic field strength based on the damping coefficient and the preset eddy current damping model. The damping coefficient is a physical quantity that describes the energy dissipation rate of a simple pendulum device. Under the action of the magnetic field, the swing amplitude of the pendulum will gradually decrease due to the eddy current damping effect. The damping coefficient can be calculated by analyzing the curve of the swing angle decaying over time. The eddy current damping model is a pre-set function model that defines the corresponding relationship between the damping coefficient and the magnetic field strength, and describes how the damping coefficient changes with the change of the magnetic field strength.

[0070] The following describes in detail how the present application calculates the damping coefficient based on the maximum swing angle, and how the magnetic field strength is calculated based on the damping coefficient and the preset eddy current damping model, in combination with the principles of mechanics and electromagnetism.

[0071] In order to more clearly understand the inventive concept of the present application, the dynamic equation of a simple pendulum device affected by a damping force in a magnetic field is first described in detail.

[0072] When a simple pendulum moves in a magnetic field, eddy currents are generated in the pendulum according to Faraday's law of electromagnetic induction. The eddy currents are acted upon by the Lorentz force, which will produce a force that hinders the motion of the pendulum, called the damping force. For a weakly damped simple pendulum motion, the effect of the damping coefficient on the period can be ignored, and its main effect is the decay rate of the amplitude.

[0073] (I) Calculate the damping coefficient based on the maximum swing angle:

[0074] See also Figure 3 As shown in the figure, a small ball is suspended by a light line that cannot be stretched, and it swings at a very small angle, which is a simple pendulum. Assuming the mass of the ball is m, the distance from the center of mass of the ball to the fulcrum O of the pendulum is l (pendulum length), and the angle is θ, then the magnitude of the tangential force acting on the ball is mgsinθ, and the tangential force always points to the equilibrium point O. When the angle θ is very small, sinθ≈θ, then the magnitude of the tangential force can be simplified to mgθ.

[0075] According to Newton's second law, the equation of motion of a particle is:

[0076] ma 切 = -mg sinθ (1)

[0077]

[0078] The above is the equation of simple harmonic motion, and the square of the angular frequency ω0 of this simple harmonic motion is equal to g / l. From this, we can get:

[0079]

[0080] There is the following relationship between the swing period T of a simple pendulum and the swing angle θ:

[0081]

[0082] For a simple pendulum, in general, if it reciprocates with a small swing angle (for example, five degrees), it has resonance, but if it reciprocates with a wide swing angle, it does not have resonance. After considering the effects of non-resonance and weak damping, the motion of the simple pendulum not only has an attenuated amplitude, but also the swing becomes dominated by the fundamental wave, a superposition of the fundamental wave and the third harmonic.

[0083] See Figure 4 As shown in the figure, the relationship between the swing period T and the swing angle θ of the simple pendulum is shown. The smaller the swing angle, the smaller the swing period T, and the larger the swing angle, the larger the swing period T. It can be seen that when the angle θ does not exceed 5°, the deviation between the measured value of the swing period and the result of the small swing approximation will not be greater than one thousandth. Therefore, the swing angle of the simple pendulum needs to be controlled within 5°.

[0084] Since the angle θ is very small, sinθ≈θ, then

[0085]

[0086]

[0087] When the pendulum with a copper pendulum hanging below is magnetically moved, eddy currents will be generated in the pendulum. These eddy currents are acted upon by the Lorentz force, thus generating a force that hinders the movement of the pendulum, which is called the magnetic damping force. It can be written as:

[0088]

[0089] Where B is the magnetic induction intensity, v is the swing speed, S is the projection area of ​​the magnetic field on the swing, t is the swing thickness, and ρ is the swing resistivity.

[0090] In addition to the eddy current damping force, the damped pendulum is also subject to air resistance F 空 and mechanical resistance F 机 For the sake of simplicity, we assume that the three factors are linearly related to the speed. Therefore, the damping coefficient β can be regarded as the sum of the three resistance damping coefficients:

[0091] β=β 磁 +β 空 +β 机 (8) Where β is the damping coefficient, β 磁 is the eddy current damping generated by the magnetic field, β 空 is air damping, β 机 For mechanical damping.

[0092] Damping force F 阻 It can be written as

[0093]

[0094] γ is the coefficient, and the equation of motion of the simple pendulum is:

[0095]

[0096]

[0097] Take the damping coefficient have to

[0098]

[0099] When the damping is weak and the angle θ is small

[0100]

[0101] The solution of the above equation is

[0102]

[0103] in is the initial phase.

[0104] From formula (14), we can see that due to the existence of damping, the amplitude will decrease exponentially over time, and the energy will be gradually dissipated in each oscillation cycle. The larger the damping coefficient β, the faster the attenuation. The formula combines the attenuation term and the oscillation term, revealing how the system gradually decreases from the initial large amplitude while maintaining the oscillation characteristics in the presence of damping.

[0105] From formula (14), we can get the damping coefficient β expression of the data processed by the difference method:

[0106]

[0107] where θ i ,θ i+6 They are the maximum swing angles of the i-th and i+6-th cycles after the swing respectively.

[0108] By using the damped motion equation in the absence of a magnetic field, the sum of the damping coefficients of air resistance and mechanical resistance can be measured, and the magnetic damping coefficient β can be obtained. 磁 :

[0109] β 磁 =β-(β 空 +β 机 ) (16)

[0110] According to formula (7), the magnetic damping coefficient β 磁 It can be written as

[0111]

[0112] Among them, m is the mass of the pendulum, v is the speed of the pendulum, S is the projected area of ​​the magnetic field on the pendulum, t is the thickness of the pendulum, B is the magnetic induction intensity, and ρ is the resistivity of the pendulum.

[0113] From formula (17), we can see that β 磁 With B 2 There is a linear relationship between them. As long as β is measured by the damping pendulum 磁 , we can get the value of magnetic induction intensity B.

[0114] From this we can see that there is a theoretically linear relationship between the damping coefficient and the square of the magnetic field intensity, which can be verified by experimental data.

[0115] In an optional implementation, since different application requirements have different requirements for measurement accuracy and sensitivity, the present application can determine the appropriate size of the pendulum according to the measurement requirements. That is, by selecting pendulums of different sizes, the measurement accuracy can be flexibly adjusted to meet different application requirements.

[0116] The pendulum is made of conductive material. When the pendulum performs a single pendulum motion in a magnetic field, eddy currents are generated inside it. The strength of the eddy current is closely related to the size of the pendulum (especially the cross-sectional area perpendicular to the direction of the magnetic field). A larger pendulum will produce stronger eddy currents, resulting in a greater damping effect. A smaller pendulum may be difficult to accurately measure its damping effect due to its weaker eddy current effect. Therefore, by changing the size of the pendulum, the strength of the eddy current effect can be adjusted, thereby affecting the attenuation speed of the swing and the sensitivity of the measurement. For example, in situations where high-precision measurement is required, a smaller pendulum may need to be selected to reduce the nonlinear influence of the eddy current effect; in situations where a fast response is required, a larger pendulum may need to be selected to enhance the eddy current effect and damping effect. Therefore, by selecting pendulums of different sizes, the measurement requirements in different application scenarios can be met.

[0117] like Figure 5 As shown, it is a flow chart of a method for verifying the validity of an eddy current damping model provided in an embodiment of the present application. The method for verifying the validity of an eddy current damping model includes the following steps.

[0118] S51, setting a simple pendulum device.

[0119] The effectiveness of the eddy current damping model is verified by a simple pendulum experiment. The first step of the experiment is to set up a simple pendulum device. The simple pendulum device includes: a pendulum body, a cycloid and a fixed fulcrum, and the pendulum body is suspended from the fixed fulcrum through the cycloid. The pendulum body of the embodiment of the present application can be selected as a copper sheet.

[0120] S52, a non-ferromagnetic metal plate is placed under the pendulum.

[0121] A non-ferromagnetic metal plate is placed underneath the copper sheet to provide a stable surface and ensure that the magnetic field does not change significantly as it passes through due to the strong magnetization of the ferromagnetic material.

[0122] Non-ferromagnetic metals refer to metals that do not have ferromagnetism (i.e., the property of not being easily magnetized), such as non-ferrous metals, some alloys, etc. In a magnetic field, non-ferromagnetic metals will not significantly enhance or change the distribution of the magnetic field. Compared with ferromagnetic metals, non-ferromagnetic metals have lower magnetic permeability and weaker response to magnetic fields. When the external magnetic field disappears, no significant residual magnetism will be left on the non-ferromagnetic metal.

[0123] S53, a magnet device capable of generating a magnetic field is placed under the metal plate.

[0124] To generate a magnetic field, a magnet arrangement is placed beneath a non-ferromagnetic metal plate.

[0125] The magnet device may be a bar magnet, a ring magnet or a magnet array, for example, to generate a stable and uniform magnetic field. Electromagnets may also be used to control the strength and distribution of the magnetic field by adjusting the current, thereby more precisely controlling the experimental conditions.

[0126] S54, adjusting the distance between the magnet and the metal plate to generate magnetic fields of different strengths.

[0127] In order to verify the effectiveness of the eddy current damping model under different magnetic field strengths, it is necessary to adjust the distance between the magnet and the metal plate. This can change the magnetic field strength passing through the copper sheet, so as to conduct multiple sets of single pendulum experiments. In each set of experiments, the magnetic field strength is changed by adjusting the distance to cover different experimental conditions.

[0128] S55, install a high-precision angle sensor near the copper pendulum.

[0129] In order to accurately measure the angle change of the copper pendulum during its swing, a high-precision angle sensor needs to be installed near the copper sheet. This sensor can capture the swing angle of the copper sheet in real time and provide accurate data for the subsequent damping coefficient calculation.

[0130] S56, releasing the copper pendulum from a small angle (less than 5°), and using a high-precision angle sensor to accurately measure and record the maximum swing angle of each cycle during the swinging process.

[0131] At the beginning of the experiment, the copper pendulum was released from a small angle position, and a high-precision angle sensor was used to accurately measure and record the maximum swing angle of the copper pendulum in each cycle during the swinging process.

[0132] S57, using a data processing device connected to the angle sensor to obtain the maximum swing angle in real time, calculating the damping coefficient according to the maximum swing angle, and calculating the experimental magnetic field intensity according to the damping coefficient and the eddy current damping model function.

[0133] S58, using a magnetic field measuring device to measure and obtain the real magnetic field strength.

[0134] In order to verify the accuracy of the experimental results, it is necessary to use a magnetic field measuring device to directly measure the real magnetic field strength generated by the magnet device at the position of the copper sheet. The magnetic field measuring device is an instrument specially used to measure the magnetic field strength and can provide accurate magnetic field strength data. Optionally, the magnetic field measuring device can be a Gauss meter.

[0135] like Figure 6 As shown, it is the damping coefficient β 磁The corresponding relationship with the real magnetic field strength B, the horizontal axis represents the square of the real magnetic field strength B, which is the magnetic field strength directly measured by a Gauss meter in a simple pendulum experiment. The vertical axis represents the damping coefficient β 磁 , is the rate at which the energy of a simple pendulum device decays due to the eddy current effect caused by the magnetic field. The larger the damping coefficient, the faster the energy decays. Figure 6 The data points in the figure represent the damping coefficient β measured at different real magnetic field strengths. 磁 The value reflects the experimental relationship between the damping coefficient and the magnetic field strength.

[0136] right Figure 6 A linear fit is performed on the data in to obtain a β describing the relationship between the damping coefficient and the magnetic field strength. 磁 -B 2 Curves, such as Figure 7 As shown, for Figure 6 The curve obtained by fitting is shown in Figure 2, and the relationship between B and β is obtained by fitting. 磁 Relationship function.

[0137] S59, verify the experimental magnetic field strength according to the real magnetic field strength.

[0138] The damping β generated by the magnetic field to be measured 磁 , substitute the fitted eddy current damping model function, calculate the experimental magnetic field strength, and compare it with the actual magnetic field strength measured by the Gauss meter. If the two are consistent within the error range, it means that the eddy current damping model is valid under experimental conditions.

[0139] according to Figure 6 Statistical analysis of the data:

[0140] β 磁 -B 2 The curve is linearly fitted, and the correlation coefficient is 0.9978, which is a relatively high positive correlation, indicating that there is a strong positive linear relationship between the magnetic field strength B square and the damping coefficient β. Such a high correlation coefficient means that when other variables are kept constant, the change in magnetic field strength can be almost completely predicted by the change in the damping coefficient.

[0141] It can be seen that although there are inevitably various errors and uncertainties in the experimental process, such as the accuracy limitation of the measuring equipment, the interference of environmental factors, and the individual differences of the samples, which lead to deviations between the experimental data and the theoretical predictions, the overall consistency proves the rationality and effectiveness of the eddy current damping model in describing the actual physical process.

[0142] In order to further verify the effectiveness of the eddy current damping model, this application also uses Comsol simulation software to simulate the eddy current distribution, such as Figure 8As shown in Figure 2, Comsol is a multi-physics field simulation software that can accurately simulate various physical phenomena such as magnetic field, electric field, fluid flow and their interactions.

[0143] After the magnetic field strength is measured, it can be applied in many fields. For example, in the design of electromagnetic equipment such as motors, transformers, and generators, measuring the magnetic field strength in the working area can optimize equipment performance, reduce energy loss, and improve efficiency. For another example, magnetic resonance imaging (MRI) is a medical technology that uses magnetic fields and radio frequency waves to image the inside of the human body. Accurately measuring the magnetic field strength can improve the resolution and clarity of MRI images. For another example, measuring the magnetic field strength in the environment can evaluate the level of electromagnetic radiation and ensure the safety of humans and the ecological environment.

[0144] The technical effects of this application are as follows:

[0145] High-precision magnetic field measurement, by utilizing the damping effect and eddy current effect, the pendulum device of the present application can achieve high-precision magnetic field measurement, meeting the demand for accurate magnetic field data in scientific research and industrial applications. By adjusting the parameters of the pendulum device, such as the size of the copper plate, magnetic field measurements of different accuracies can be achieved.

[0146] Non-contact measurement: No direct contact with the object being measured is required. The device is particularly suitable for extreme environments such as high temperature and high pressure. It solves the limitations of traditional measurement methods in these environments and expands the application scenarios of magnetic field measurement.

[0147] Wide measurement range: Theoretically, the simple pendulum device can achieve a wide range of magnetic field measurements from zero to extremely large. Through appropriate eddy current damping models and experimental device design, it can cover magnetic fields of various intensities and meet the measurement needs of different fields.

[0148] Real-time monitoring capability: It has real-time monitoring function and can dynamically track changes in the magnetic field. It is of great significance for application scenarios that require real-time monitoring of the magnetic field state (such as magnetic resonance imaging, eddy fluid dynamics research, etc.).

[0149] Low cost and high efficiency: The pendulum device has a simple structure and is composed of low-cost materials such as a pendulum and a magnet. It has a low manufacturing cost while maintaining high measurement accuracy, meeting the requirements of economic efficiency and cost-effectiveness.

[0150] In summary, the present application realizes a new method of magnetic field measurement by using a mechanical simple pendulum device combined with the principle of eddy current effect.

[0151] Fig. 9 A schematic diagram of the structure of a system for measuring magnetic field strength provided in an embodiment of the present application.

[0152] The system 9 for measuring magnetic field strength is used to measure magnetic field strength, and includes: a simple pendulum device 90 , an angle sensor 91 and a data processing device 92 .

[0153] Among them, the simple pendulum device 90 may include: a pendulum body, a cycloid and a fixed fulcrum. The pendulum body is a pendulum ball or pendulum piece made of conductive material, which is suspended on the fixed fulcrum through the cycloid. The cycloid adopts a lightweight and non-stretchable thin wire or thin rod to ensure that the fixed fulcrum is stable and vertical to reduce interference with the movement of the simple pendulum.

[0154] The angle sensor 91 is installed at the center or near the center of mass of the pendulum, and is used to measure and record the angle data of the pendulum during the swinging process after starting the pendulum device, and the angle data includes the maximum swing angle of each cycle. The maximum swing angle refers to the angle corresponding to the maximum distance that the pendulum deviates from the equilibrium position.

[0155] The data processing device 92 is used to receive the maximum swing angle sent by the angle sensor, calculate the damping coefficient according to the maximum swing angle, and calculate the magnetic field strength according to the damping coefficient and a preset eddy current damping model.

[0156] Fig.10 A schematic diagram of the structure of a computer device provided in an embodiment of the present application.

[0157] The computer device includes a processor, a memory, a network interface and a database connected through a system bus. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile and / or volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface of the computer device is used to communicate with an external client through a network connection.

[0158] When the computer program is executed by a processor, the following steps are implemented:

[0159] Get the maximum swing angle;

[0160] Calculating a damping coefficient according to the maximum swing angle;

[0161] The magnetic field strength is calculated based on the damping coefficient and a preset eddy current damping model.

[0162] In an optional implementation, the processor calculates the damping coefficient according to the maximum swing angle using the following formula:

[0163] β 磁 =β-β 空 -β 机 ,

[0164] in, where θ i ,θ i+6 are the maximum swing angles of the ith and i+6th cycles after the swing, respectively. 空 is the damping coefficient of air resistance, β 机 is the damping coefficient of mechanical resistance. The sum of the damping coefficient of air resistance and the damping coefficient of mechanical resistance is calculated through a set of simple pendulum experiments without magnetic field.

[0165] In an optional embodiment, the preset eddy current damping model is a function model between a damping coefficient and a magnetic field strength that is pre-set through calibration.

[0166] In an optional implementation, the function model is:

[0167]

[0168] Among them, S is the projection area of ​​the magnetic field on the pendulum, t is the thickness of the pendulum, B is the magnetic induction intensity, m is the mass of the pendulum, and ρ is the resistivity of the pendulum.

[0169] It should be noted that the functions or steps that can be implemented by the computer-readable storage medium or computer device can be found in the aforementioned method embodiments. To avoid repetition, they will not be described one by one here.

[0170] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0171] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0172] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for measuring magnetic field strength, characterized in that: The method comprises: A simple pendulum device for measuring the magnetic field strength is arranged in the area to be measured; Using an angle sensor to measure the maximum swing angle of each cycle during the swinging process of the simple pendulum device; The computer program algorithm is used to process the data to obtain the damping coefficient generated by the magnetic field, and the magnetic field strength is calculated using the damping coefficient and the preset eddy current damping model function.

2. The method for measuring magnetic field strength according to claim 1, characterized in that: The data processing device calculates the damping coefficient according to the maximum swing angle using the following formula: β 磁 ＝β-(β 空 +β 机 )， in, where θ i ,θ i+6 are the maximum swing angles of the ith and i+6th cycles after the swing, β 空 is the damping coefficient of air resistance, β 机 is the damping coefficient of mechanical resistance. The sum of the damping coefficient of air resistance and the damping coefficient of mechanical resistance is measured through a set of simple pendulum experiments without magnetic field.

3. The method for measuring magnetic field strength according to claim 1, characterized in that: The preset eddy current damping model is a function model between a preset damping coefficient and a magnetic field strength.

4. The method for measuring magnetic field strength according to claim 3, characterized in that: The function model is: Among them, S is the projection area of ​​the magnetic field on the pendulum, t is the thickness of the pendulum, B is the magnetic induction intensity, m is the mass of the pendulum, and ρ is the resistivity of the pendulum.

5. The method for measuring magnetic field strength according to any one of claims 1 to 4, characterized in that: The method further comprises: The effectiveness of the eddy current damping model is verified through a single pendulum experiment.

6. The method for measuring magnetic field strength according to claim 5, characterized in that: The verification of the effectiveness of the eddy current damping model by a single pendulum experiment includes: A single pendulum device is provided in which the pendulum body is a copper sheet; The copper pendulum is placed in an experimental magnetic field of an electromagnet gap; An angle sensor is installed near the copper pendulum; The copper pendulum is released from a small-angle swing position of less than 5 degrees, and the angle sensor is used to measure and record the maximum swing angle of each cycle during the swing process; The damping coefficient is calculated using the maximum swing angle data, and the experimental magnetic field strength is calculated based on the damping coefficient and a calibrated preset eddy current damping model function; Use a magnetic field measuring device to measure the real magnetic field strength; The experimental magnetic field strength is verified according to the real magnetic field strength.

7. A system for measuring magnetic field strength, characterized in that: The system comprises: Single pendulum device; An angle sensor, used to measure the maximum swing angle of each cycle during the swinging process of the pendulum of the simple pendulum device; A data processing device is used to obtain the maximum swing angle measured by the angle sensor, calculate the damping coefficient according to the maximum swing angle, and calculate the magnetic field strength according to the damping coefficient and a preset eddy current damping model function.

8. A computer device, characterized in that: The computer device comprises: a memory storing a computer program; The processor implements the following steps when executing the computer program: Store and read angle sensor data, and obtain the maximum swing angle through the peak-finding algorithm program; Calculating a damping coefficient according to the maximum swing angle; The magnetic field strength is calculated based on the damping coefficient and a preset eddy current damping model function.

9. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the following steps are implemented: Store and record angle sensor data and maximum swing angle; Calculating a damping coefficient according to the maximum swing angle; The magnetic field strength is calculated based on the damping coefficient and a preset eddy current damping model function.

10. A program for obtaining magnetic field strength by data processing and calculation, characterized in that: The computer program comprises: Read the angle sensor data and obtain the maximum swing angle through the peak-finding algorithm program; The damping coefficient is calculated using the maximum swing angle; The magnetic field strength is calculated based on the damping coefficient and a preset eddy current damping model function, and the magnetic field strength is displayed in real time.

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