Automatic thermistor chip size identification method and system based on PLC control

Abstract

The invention relates to the technical field of thermistors, in particular to a thermistor chip size automatic identification method based on PLC control. According to the invention, the related characteristics are calculated by acquiring the magnetic field reaction data of the thermistor chip in the preset magnetic field, and the output signal characteristics, the impedance characteristics and the magnetic field distribution characteristics of the chip can be acquired more accurately through the analysis and digital processing of the analog signals; by comprehensively utilizing multi-dimensional signals such as reflection coefficient, transmission coefficient, chip magnetic response frequency and the like, the characteristics of an object can be analyzed more comprehensively, so that higher measurement precision can be maintained under different conditions; the magnetic flux density is obtained through magnetic field distribution characteristics, then the penetration depth is calculated, the chip thickness is calculated by combining the magnetic response frequency and the relative permeability of the chip, and the magnetic flux density, the penetration depth, the magnetic response frequency of the chip, the relative permeability and other physical characteristics are analyzed. The magnetic characteristics and geometric characteristics of the chip material can be comprehensively considered, and the accuracy of thickness calculation can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of thermistors, and in particular to a method and system for automatically identifying the size of a thermistor chip based on PLC control. Background Art

[0002] Thermistor chip is an electronic component used for temperature measurement and temperature compensation. Its resistance value changes with temperature. The resistance characteristics of thermistor make it widely used in temperature sensors, temperature control circuits, battery protection, instruments and meters, household appliances and other fields.

[0003] Since thermistor chips are usually used to measure temperature, their resistance value changes with temperature. The thickness of the thermistor directly affects its thermal response speed and accuracy. Therefore, size identification helps to confirm the volume of the chip, thereby ensuring that it can quickly respond to temperature changes in a given application. The working principle of thermistors is based on the fact that the resistance of the material changes with temperature, and the thickness of the chip has an important influence on the thermal response speed of the thermistor. Identifying the thickness of the thermistor chip can ensure that the thermal response speed, accuracy and temperature characteristics of the chip meet the application requirements. The method for identifying the thickness of the thermistor chip in the prior art is to measure the distance between the surface of the object and the sensor by laser reflection, thereby inferring the thickness of the thermistor chip. However, the above method has the problem of a large error range in inferring the thickness by sensing the distance. Summary of the invention

[0004] The main purpose of the present invention is to provide a method for automatically identifying the size of a thermistor chip based on PLC control, aiming to solve the technical problems in the prior art.

[0005] The present invention proposes a method for automatically identifying the size of a thermistor chip based on PLC control, which is applied to a PLC control system and includes: Acquire magnetic field response data of the thermistor chip under a preset magnetic field, and acquire a magnetic field simulation signal according to the magnetic field response data; Converting the magnetic field analog signal into a magnetic field digital signal through an analog-to-digital converter; Inputting the magnetic field digital signal into a PLC control system to obtain a digitized magnetic field characteristic, wherein the digitized magnetic field characteristic includes an output signal characteristic, an impedance characteristic, and a magnetic field distribution characteristic; Acquire a reflection coefficient and a transmission coefficient according to the output signal characteristics, and acquire a chip magnetic response frequency according to the reflection coefficient and the transmission coefficient; Acquire an inductance value according to the impedance characteristic, and acquire a relative magnetic permeability according to the inductance value; Acquiring magnetic flux density according to the magnetic field distribution characteristics; The penetration depth is obtained according to the magnetic flux density, and the chip thickness is obtained according to the penetration depth, the chip magnetic response frequency and the relative magnetic permeability.

[0006] Preferably, the step of obtaining a reflection coefficient and a transmission coefficient according to the output signal characteristics, and obtaining a magnetic response frequency of the chip according to the reflection coefficient and the transmission coefficient comprises: Acquire the time domain signal characteristics and phase characteristics of the thermistor chip under a preset magnetic field according to the output signal characteristics; Performing Fourier transformation on the time domain signal characteristics to obtain an amplitude spectrum; The reflection coefficient is calculated according to the amplitude spectrum and phase characteristics, wherein the calculation formula is: ; Among them, F(SX) represents the reflection coefficient, F(DP) represents the amplitude spectrum, and X(T) represents the phase characteristic; The transmission coefficient is calculated according to the reflection coefficient, wherein the calculation formula is: ; Where, T(SX) represents the transmission coefficient, and F(SX) represents the reflection coefficient; Acquire a rising frequency curve according to the reflection coefficient, and acquire a falling frequency curve according to the transmission coefficient; Obtaining a first frequency corresponding to each first connection point in the rising frequency curve, and obtaining a first mean frequency according to the plurality of first frequencies; Acquire a second frequency corresponding to each second connection point in the decreasing frequency curve, and acquire a second mean frequency according to the plurality of second frequencies; The chip magnetic response frequency is obtained according to the first mean frequency and the second mean frequency.

[0007] Preferably, the step of acquiring a rising frequency curve according to the reflection coefficient comprises: Obtaining a preset frequency table, wherein the preset frequency table includes a plurality of frequencies arranged in order of magnitude; Obtaining a first amplitude value corresponding to the reflection coefficient at each frequency in a preset frequency table; The frequency-amplitude coordinate axis is established with frequency as the X-axis and amplitude value as the Y-axis; Taking the first amplitude values ​​as first connection points, and connecting them sequentially through a curve and plotting them on the time-amplitude coordinate axis, to obtain a first frequency response curve; Acquire a plurality of first turning points of the first frequency response curve, and truncate the first frequency response curve according to the plurality of first turning points to obtain a plurality of first truncation curves; The first slope corresponding to each of the first truncation curves is obtained, and the first truncation curve corresponding to the largest first slope is selected as the rising frequency curve.

[0008] Preferably, the step of obtaining an inductance value according to the impedance characteristic, and obtaining a relative magnetic permeability according to the inductance value comprises: Acquire complex impedance and impedance resistance according to the impedance characteristics; Obtaining reaction impedance according to the complex impedance and impedance resistance; Obtain the response frequency and size characteristics of the thermistor chip under a preset magnetic field; Acquire an angular frequency according to the reaction frequency, and acquire an inductance value according to the angular frequency and the reaction impedance; Obtaining the cross-sectional area and path length of the thermistor chip in a preset magnetic field action area according to the size characteristics; The vacuum magnetic permeability is obtained, and the relative magnetic permeability is obtained according to the vacuum magnetic permeability, the inductance value, the cross-sectional area and the path length.

[0009] Preferably, the step of obtaining the magnetic flux density according to the magnetic field distribution characteristics comprises: Acquire the reaction magnetic field strength at multiple positions of the thermistor chip according to the magnetic field distribution characteristics; Obtaining the corresponding chip reaction region area according to each of the reaction magnetic field strengths; Obtaining a corresponding magnetic susceptibility according to the area of ​​each chip reaction region, and obtaining a corresponding effective magnetic field strength according to each magnetic susceptibility and the corresponding reaction magnetic field strength; Acquire an average effective magnetic field strength according to the multiple effective magnetic field strengths; The relative magnetic permeability of the thermistor chip is obtained, and the magnetic flux density is obtained according to the relative magnetic permeability and the average effective magnetic field strength.

[0010] Preferably, the step of obtaining the penetration depth according to the magnetic flux density, and obtaining the chip thickness according to the penetration depth, the chip magnetic response frequency and the relative magnetic permeability comprises: Acquire multiple central magnetic field intensities of the center position of the thermistor chip under a preset magnetic field within a preset time period; Obtaining a magnetic field change rate according to multiple center magnetic field intensities and a preset time period; Obtaining the current frequency according to the magnetic flux density and the magnetic field change rate; The conductivity and relative magnetic permeability of the thermistor chip are obtained, and the penetration depth is calculated according to the relative magnetic permeability, current frequency and conductivity, wherein the calculation formula is: ; Where, C(TS) represents the penetration depth, X(CD) represents the relative magnetic permeability, D(DL) represents the electrical conductivity, and D(LP) represents the current frequency; The chip thickness is calculated according to the penetration depth, the chip magnetic response frequency and the relative magnetic permeability, wherein the calculation formula is: ; Among them, X(HC) represents the chip thickness, C(TS) represents the penetration depth, X(CD) represents the relative magnetic permeability, and G(ZP) represents the chip magnetic response frequency.

[0011] The present application also provides a thermistor chip size automatic identification system based on PLC control, which is applied to a PLC control system, including: A first acquisition module is used to acquire magnetic field response data of the thermistor chip under a preset magnetic field, and acquire a magnetic field simulation signal according to the magnetic field response data; A conversion module, used for converting the magnetic field analog signal into a magnetic field digital signal through an analog-to-digital converter; An input module, used for inputting the magnetic field digital signal into a PLC control system to obtain a digitized magnetic field characteristic, wherein the digitized magnetic field characteristic includes an output signal characteristic, an impedance characteristic and a magnetic field distribution characteristic; A second acquisition module, used to acquire a reflection coefficient and a transmission coefficient according to the output signal characteristics, and to acquire a chip magnetic response frequency according to the reflection coefficient and the transmission coefficient; A third acquisition module, used to acquire an inductance value according to the impedance characteristic, and acquire a relative magnetic permeability according to the inductance value; A fourth acquisition module, used to acquire magnetic flux density according to the magnetic field distribution characteristics; The fifth acquisition module is used to acquire the penetration depth according to the magnetic flux density, and acquire the chip thickness size according to the penetration depth, the chip magnetic response frequency and the relative magnetic permeability.

[0012] Preferably, the third acquisition module comprises: A first acquisition unit, configured to acquire complex impedance and impedance resistance according to the impedance characteristic; A second acquisition unit, used for acquiring a reaction impedance according to the complex impedance and the impedance resistance; A third acquisition unit is used to acquire the response frequency and size characteristics of the thermistor chip under a preset magnetic field; a fourth acquisition unit, configured to acquire an angular frequency according to the reaction frequency, and acquire an inductance value according to the angular frequency and the reaction impedance; A fifth acquisition unit, configured to acquire a cross-sectional area and a path length of the thermistor chip in a preset magnetic field action area according to the size feature; The sixth acquisition unit is used to acquire the vacuum magnetic permeability, and acquire the relative magnetic permeability according to the vacuum magnetic permeability, inductance, cross-sectional area and path length.

[0013] The present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the above-mentioned method for automatically identifying the size of a thermistor chip based on PLC control are implemented.

[0014] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned method for automatically identifying the size of a thermistor chip based on PLC control are implemented.

[0015] The beneficial effects of the present invention are as follows: the present invention can obtain the magnetic field response data of the thermistor chip under a preset magnetic field to infer relevant characteristics and can more accurately obtain the output signal characteristics, impedance characteristics and magnetic field distribution characteristics of the chip through analysis and digital processing of analog signals. By analyzing the magnetic field response data of the thermistor chip, multi-dimensional digital magnetic field characteristics can be obtained. The magnetic field analog signal is converted into a digital signal through an analog-to-digital converter and then input into a PLC control system for processing, so that real-time and efficient data analysis and response can be achieved. By calculating parameters such as reflection coefficient and transmission coefficient, not only the distance between the object and the sensor can be obtained, but also other important physical characteristics can be inferred. By comprehensively utilizing multi-dimensional signals such as reflection coefficient, transmission coefficient, and chip magnetic response frequency, the characteristics of the object can be analyzed more comprehensively, so that high measurement accuracy can be maintained under different conditions. The magnetic flux density is obtained through the magnetic field distribution characteristics, and then the penetration depth is inferred and the chip thickness is calculated in combination with the chip magnetic response frequency and relative magnetic permeability. Through multi-dimensional analysis of physical properties such as magnetic flux density, penetration depth, chip magnetic response frequency, and relative magnetic permeability, the magnetic characteristics and geometric characteristics of the chip material can be comprehensively considered, and it does not rely solely on a single measurement signal. This multi-dimensional information analysis helps to improve the accuracy of thickness calculation and reduce the errors that may be introduced by a single measurement signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure is a schematic diagram of a method flow according to an embodiment of the present invention.

[0017] Figure 2 FIG. 1 is a schematic diagram of a device structure according to an embodiment of the present invention.

[0018] Figure 3 A schematic diagram of the internal structure of a computer device according to an embodiment of the present application.

[0019] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0020] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0021] like Figure 1-Figure 3 As shown, the present application provides a method for automatically identifying the size of a thermistor chip based on PLC control, which is applied to a PLC control system, comprising: S1, obtaining magnetic field response data of the thermistor chip under a preset magnetic field, and obtaining a magnetic field simulation signal according to the magnetic field response data; S2, converting the magnetic field analog signal into a magnetic field digital signal through an analog-to-digital converter; S3, inputting the magnetic field digital signal into a PLC control system to obtain a digitized magnetic field characteristic, wherein the digitized magnetic field characteristic includes an output signal characteristic, an impedance characteristic and a magnetic field distribution characteristic; S4, obtaining a reflection coefficient and a transmission coefficient according to the output signal characteristics, and obtaining a chip magnetic response frequency according to the reflection coefficient and the transmission coefficient; S5. Obtaining an inductance value according to the impedance characteristic, and obtaining a relative magnetic permeability according to the inductance value; S6. Obtaining magnetic flux density according to the magnetic field distribution characteristics; S7. Obtain the penetration depth according to the magnetic flux density, and obtain the chip thickness according to the penetration depth, the chip magnetic response frequency and the relative magnetic permeability.

[0022] As described in the above steps S1-S2, the thermistor chip is an electronic component used for temperature measurement and temperature compensation, and its resistance value changes with the change of temperature. The resistance characteristics of the thermistor make it widely used in the fields of temperature sensors, temperature control circuits, battery protection, instruments, household appliances, etc. Since thermistor chips are usually used to measure temperature, their resistance value changes with the change of temperature. The thickness of the thermistor directly affects its thermal response speed and accuracy. Therefore, size identification helps to confirm the volume of the chip, and the thickness of the thermistor chip has an important influence on the thermal response speed of the thermistor. Thinner thermistor chips have faster thermal response speeds because thinner chips can reach thermal equilibrium with the ambient temperature more quickly. On the contrary, thicker chips have slower response speeds due to their larger thermal inertia, thereby ensuring that they can quickly respond to temperature changes in a given application. The method for identifying the thickness size of thermistor chips in the prior art is to measure the distance between the surface of the object and the sensor by laser reflection, thereby inferring the thickness size of the thermistor chip, but the above method has the problem of a large error range in inferring the thickness size by sensing the distance. The present invention obtains magnetic field response data of the thermistor chip under a preset magnetic field, obtains a magnetic field analog signal according to the magnetic field response data, then converts the magnetic field analog signal into a magnetic field digital signal through an analog-to-digital converter, and inputs the magnetic field digital signal into a PLC control system to obtain a digitized magnetic field characteristic, wherein the digitized magnetic field characteristic includes an output signal characteristic, an impedance characteristic, and a magnetic field distribution characteristic. The output signal characteristic, the impedance characteristic, and the magnetic field distribution characteristic are deduced by obtaining the magnetic field response data of the thermistor chip under a preset magnetic field, wherein the magnetic field response number refers to the performance change (including resistance change, signal response change, conductivity, etc.) of the thermistor chip under the action of the magnetic field. Compared with the laser reflection method, the error that may be caused by surface unevenness, light scattering, reflection angle problems and other external factors is avoided. The laser ranging method usually requires precise reflection conditions, otherwise the measurement result may be affected. The influence of factors such as surface gloss, color, and angle can lead to inaccurate results. However, since the magnetic field response is independent of the surface optical properties, these problems can be overcome. Through the analysis and digital processing of analog signals, the output signal characteristics, impedance characteristics, and magnetic field distribution characteristics of the chip can be obtained more accurately. By analyzing the magnetic field response data of the thermistor chip, multi-dimensional digital magnetic field characteristics can be obtained. These characteristics help to more comprehensively evaluate the quality and performance of the chip. Compared with the traditional laser reflection measurement method, the magnetic field response can provide more intrinsic characteristic information about the chip itself, which helps to better control quality and optimize design. The magnetic field analog signal is converted into a digital signal through an analog-to-digital converter and then input into the PLC control system for processing, which can achieve real-time and efficient data analysis and response. This digital processing enables the system to have a higher level of automation and improves detection accuracy.The reflection coefficient and transmission coefficient are obtained through the output signal characteristics, and the magnetic response frequency of the chip is obtained based on the reflection coefficient and transmission coefficient. The inductance value is obtained through the impedance characteristics, and the relative magnetic permeability is obtained based on the inductance value. Among them, the reflection coefficient is the ratio of the amplitude of the reflected wave to the amplitude of the incident wave, and the transmission coefficient is the ratio of the amplitude of the transmitted wave to the amplitude of the incident wave. The reflection coefficient represents the reflection intensity of the electromagnetic wave on the interface, which is affected by parameters such as the conductivity and magnetic permeability of the chip medium, thereby changing the reflection coefficient. As the frequency changes, the magnetic response of the chip may cause the reflection coefficient to mutate at certain frequencies, while the transmission coefficient represents the amplitude of the electric The transmission intensity of magnetic waves through the chip. The change of magnetic permeability of chip materials at different frequencies will affect the propagation speed of waves, wave impedance and other characteristics, thereby affecting the transmission coefficient. The chip magnetic response frequency usually refers to the frequency in the thermistor chip where fluctuations (such as electromagnetic waves or sound waves) produce strong reflection / transmission or the magnetic response of the chip reaches a significant change, which will cause the reflection coefficient to reach the maximum value or the transmission coefficient to reach the minimum value. When the transmission coefficient reaches the minimum value, it means that the transmission intensity of electromagnetic waves is the weakest, which usually occurs when the chip material absorbs electromagnetic waves or hinders the propagation of electromagnetic waves the most. At this time, the magnetic permeability of the chip material is at a specific frequency. The sharp change in the rate may lead to the absorption peak of the electromagnetic wave, that is, the magnetic response frequency. Among them, the absorption peak usually refers to the frequency point where the chip material absorbs the strongest electromagnetic wave energy. At this frequency, the chip material absorbs the electromagnetic wave the most. Therefore, near the chip magnetic response frequency, the reflection coefficient often shows a significant peak value. The transmission coefficient usually has a minimum value near the chip magnetic response frequency. Therefore, at this frequency, the transmission coefficient reaches the minimum and the reflection coefficient reaches the maximum. By analyzing the signal characteristics, such as the reflection coefficient and the transmission coefficient, the signal change can be compensated to a certain extent, thereby reducing the error caused by surface unevenness or material changes. By calculating parameters such as the reflection coefficient and the transmission coefficient, the system can not only obtain the distance between the object and the sensor, but also infer other important physical properties (such as the chip magnetic response frequency, impedance, inductance, etc.). For example, in the system of electromagnetic wave propagation, the reflection coefficient is closely related to the characteristic impedance of the material. By measuring the reflection coefficient, the impedance of the system can be inferred, and then the electromagnetic properties of the material can be inferred. For electromagnetic waves in transmission lines or waveguides, the relationship between the reflection coefficient and the incident wave and the reflected wave can be described by the characteristic impedance. According to the reflection coefficient formula, , where R represents the reflection coefficient, Z1 represents the load impedance, and Z0 represents the characteristic impedance of the transmission line. When the reflection coefficient is known, the load impedance can be inferred according to the above formula, which helps to fully understand the characteristics of the object, especially for the measurement of tiny sizes such as the thickness of thermistor chips. In addition, since traditional laser reflection measurement often relies on a single distance signal, it is easily limited by the surface state and material properties. By comprehensively utilizing multi-dimensional signals such as reflection coefficient, transmission coefficient, and chip magnetic response frequency, the characteristics of the object can be analyzed more comprehensively, the robustness of the system can be enhanced, and a high measurement accuracy can be maintained under different conditions. The magnetic flux density is obtained through the magnetic field distribution characteristics, and the magnetic flux is obtained through the magnetic flux. The penetration depth is obtained by density, and the chip thickness is obtained according to the penetration depth, chip magnetic response frequency and relative magnetic permeability. Among them, the penetration depth is the depth when the electromagnetic wave decays to the original intensity in the chip, which usually refers to the attenuation degree of the electromagnetic wave in the conductive material. The thickness of the chip is inferred by the magnetic field response through the analysis of the magnetic field distribution characteristics. It has nothing to do with the optical properties of the surface of the object, is not affected by the changes in the surface optical conditions, and avoids optical reflection errors. Specifically, the magnetic flux density is obtained through the magnetic field distribution characteristics, and then the penetration depth is inferred, and the chip thickness is calculated in combination with the chip magnetic response frequency and relative magnetic permeability. For example, the thickness of the chip is directly related to the propagation and reflection of electromagnetic waves and the magnetoelectric properties of the material. Specifically, the chip thickness is inferred by combining the penetration depth, the chip magnetic response frequency and the relative magnetic permeability. The following factors can be used to understand: the chip will show resonance at certain frequencies, which affects the reflection, penetration and other behaviors of electromagnetic waves. The chip magnetic response frequency is affected by the chip thickness, material properties, etc. If the chip magnetic response frequency of the chip is known, combined with the relative magnetic permeability and electrical conductivity of the material, the corresponding chip thickness can be calculated. Or in a chip containing magnetic materials, the change in magnetic permeability will affect the propagation speed, attenuation and reflection of electromagnetic waves in the material, thereby affecting the penetration depth. If the magnetic permeability of the material and the frequency of the electromagnetic wave are known, the propagation characteristics of the electromagnetic wave can be inferred, and then the thickness of the chip can be calculated. Compared with the indirect inference method of laser reflection, magnetic field measurement has higher accuracy and stability. Through multi-dimensional analysis of physical properties such as magnetic flux density, penetration depth, chip magnetic response frequency, relative magnetic permeability, etc., the magnetic characteristics and geometric characteristics of the chip material can be comprehensively considered, not just relying on a single measurement signal. This multi-dimensional information analysis helps to improve the accuracy of thickness calculation and reduce the errors that may be introduced by a single measurement signal.

[0023] In one embodiment, the step S4 of acquiring the reflection coefficient and the transmission coefficient according to the output signal characteristics, and acquiring the magnetic response frequency of the chip according to the reflection coefficient and the transmission coefficient, comprises: S41, acquiring the time domain signal characteristics and phase characteristics of the thermistor chip under a preset magnetic field according to the output signal characteristics; S42, performing Fourier transform on the time domain signal feature to obtain an amplitude spectrum; S43, calculating the reflection coefficient according to the amplitude spectrum and phase characteristics, wherein the calculation formula is: ; Among them, F(SX) represents the reflection coefficient, F(DP) represents the amplitude spectrum, and X(T) represents the phase characteristic; S44, calculating the transmission coefficient according to the reflection coefficient, wherein the calculation formula is: ; Where, T(SX) represents the transmission coefficient, and F(SX) represents the reflection coefficient; S45, acquiring an ascending frequency curve according to the reflection coefficient, and acquiring a descending frequency curve according to the transmission coefficient; S46, obtaining a first frequency corresponding to each first connection point in the rising frequency curve, and obtaining a first mean frequency according to the plurality of first frequencies; S47, obtaining a second frequency corresponding to each second connection point in the decreasing frequency curve, and obtaining a second mean frequency according to the plurality of second frequencies; S48. Obtain the chip magnetic response frequency according to the first mean frequency and the second mean frequency.

[0024] As described in the above steps S41-S48, the present invention obtains time domain signal characteristics and phase characteristics through output signal characteristics, and performs Fourier transform on the time domain signal characteristics to obtain an amplitude spectrum, and calculates the reflection coefficient through the amplitude spectrum and phase characteristics. Specifically, the principle of calculating the reflection coefficient based on the amplitude spectrum and phase characteristics involves wave propagation, reflection and interference phenomena. The reflection coefficient reflects the relative intensity and phase difference between the incident wave and the reflected wave, and the amplitude spectrum and phase characteristics provide complete waveform information. Specifically, the reflection coefficient is a complex number that includes the amplitude and phase information of the reflected wave. Usually, the reflection coefficient is determined by measuring the frequency domain characteristics of the incident wave and the reflected wave. If the amplitude spectrum and phase spectrum of the incident wave and the reflected wave are known, the amplitude of the reflection coefficient can be calculated according to the ratio of the amplitude of the reflected wave to the amplitude of the incident wave, and the phase of the reflection coefficient is the phase difference between the reflected wave and the incident wave. Since the reflection coefficient is a complex number, consisting of amplitude and phase, the reflection coefficient can be calculated by the amplitude and phase difference, and then the transmission coefficient is calculated according to the reflection coefficient. Since the reflection coefficient and the transmission coefficient are interrelated, and since the thermistor chip is in a preset magnetic field at this time, and since there is no other loss at this time, that is, energy conservation, the energy of the incident wave is equal to the energy of the reflected wave plus the energy of the transmitted wave. Among them, the amplitude spectrum refers to the amplitude distribution of the signal at different frequencies, indicating the frequency components of the signal and the intensity of each frequency component. By using time domain signal characteristics and phase characteristics, the interference of surface reflection can be reduced, because this method mainly relies on the frequency domain characteristics of the signal, such as amplitude spectrum, phase spectrum, etc., and does not directly rely on the surface reflection characteristics, thereby effectively reducing the error caused by changes in surface conditions. After obtaining the amplitude spectrum and phase characteristics through Fourier transform, the behavior of the signal at different frequencies can be more accurately analyzed, especially When the signal is interfered by noise in the time domain, frequency domain analysis can help separate useful signals and noise, thereby improving the reliability of the measurement results. By calculating the reflection coefficient and the transmission coefficient, not only can the distance be measured, but also the physical properties of the object, such as dielectric constant and magnetic permeability, can be analyzed. This makes the thickness measurement accuracy and depth of the thermistor chip higher. First, the rising frequency curve is obtained through the reflection coefficient, and the falling frequency curve is obtained through the transmission coefficient. Then, the first frequency corresponding to each first connection point in the rising frequency curve is obtained. Specifically, the reflection coefficient is usually lower when the frequency is lower, but as the frequency increases, the reflection coefficient usually increases gradually, especially at the chip magnetic response frequency close to the chip, the reflection will be significantly enhanced. Therefore, the rising frequency curve corresponding to the reflection coefficient and the falling frequency curve corresponding to the transmission coefficient are obtained, and the first mean frequency is obtained according to multiple first frequencies. The second frequency corresponding to each second connection point in the falling frequency curve is obtained, and the second mean frequency is obtained according to multiple second frequencies. Finally, the chip magnetic response frequency can be calculated by the average of the sum of the first mean frequency and the second mean frequency.Specifically, the first mean frequency is the frequency mean of the area corresponding to the truncation curve with the largest slope in the reflection coefficient, and the second mean frequency is the frequency mean of the area corresponding to the truncation curve with the smallest slope in the transmission coefficient. In addition, the chip magnetic response frequency is the frequency that occurs when the reflection coefficient reaches the maximum value or the transmission coefficient reaches the minimum value. Therefore, the chip magnetic response frequency can be obtained by calculating half of the sum of the first mean frequency and the second mean frequency. By obtaining the rising frequency and falling frequency curves corresponding to the reflection coefficient and the transmission coefficient respectively, since the reflection coefficient and the transmission coefficient respectively reflect the reflection and penetration behaviors of the magnetic field on the surface of the object, they are affected by the surface morphology, material properties and thickness, etc. By accurately calculating the mean frequency of these frequency curves, the actual characteristics of the object can be more accurately reflected, and the error caused by a single measurement method can be reduced. By obtaining multiple first frequencies and second frequencies and calculating the mean frequency, the influence of accidental errors and system noise can be effectively reduced, so that the final calculated chip magnetic response frequency has higher stability and reliability, thereby improving the measurement accuracy of the thickness of the thermistor chip. By combining the reflection coefficient and transmission coefficient method and using the characteristics of the frequency curve, it is possible to eliminate or reduce the nonlinear error in the measurement result caused by the laser reflection measurement method, which may be affected by factors such as the laser beam angle, the smoothness of the reflection surface, and the shape of the object.

[0025] In one embodiment, the step S45 of acquiring a rising frequency curve according to the reflection coefficient includes: S451, obtaining a preset frequency table, wherein the preset frequency table includes a plurality of frequencies arranged in order of magnitude; S452, obtaining a first amplitude value corresponding to the reflection coefficient at each frequency in a preset frequency table; S453, establish a frequency-amplitude coordinate axis with frequency as the X-axis and amplitude as the Y-axis; S454, using the plurality of first amplitude values ​​as first connection points, and sequentially connecting them through a curve and plotting them on a time-amplitude coordinate axis to obtain a first frequency response curve; S455, acquiring a plurality of first turning points of the first frequency response curve, and truncating the first frequency response curve according to the plurality of first turning points to obtain a plurality of first truncation curves; S456: Obtain the first slope corresponding to each of the first truncation curves, and select the first truncation curve corresponding to the largest first slope as the rising frequency curve.

[0026] As described in the above steps S451-S456, the method of obtaining the falling frequency curve according to the transmission coefficient is the same as that of the present embodiment and will not be described here. The present invention obtains a plurality of preset frequencies arranged in order of magnitude, and obtains the corresponding first amplitude value of the reflection coefficient at each frequency in the preset frequency table. Specifically, the amplitude value of the reflected signal at different frequencies is obtained by an instrument (such as a network analyzer). For example, to obtain the reflection coefficient amplitude value of a transmission line in the frequency range of 1GHZ to 5GHZ, some discrete frequency points may be selected, such as 1GHZ, 2GHZ, 3GHZ, 4GHZ, and 5GHZ, and then the reflection coefficient of each frequency point may be measured by using a network analyzer, and then the reflection coefficient of each reflection point may be obtained according to the reflection coefficient of each reflection point. The corresponding amplitude value is obtained from the coefficient, and then the frequency-amplitude coordinate axis is established with the frequency as the X-axis and the amplitude value as the Y-axis. The multiple first amplitude values ​​are used as the first connection points and are connected in sequence through curves and plotted on the time-amplitude coordinate axis to obtain the first frequency response curve. The relationship between the reflection coefficient and the amplitude value at different frequencies can be captured more accurately through the frequency-amplitude curve. This detailed frequency response curve can effectively avoid errors in traditional laser reflection measurement. By combining multi-frequency reflection coefficient data, it can effectively reduce possible interference at a single frequency and improve the robustness of the measurement system. By accurately establishing the frequency response curve, the thickness estimation error caused by laser reflection error can be reduced, thereby improving the quality control accuracy of the chip. By obtaining a plurality of first turning points of the first frequency response curve, and truncating the first frequency response curve according to the plurality of first turning points to obtain a plurality of first truncated curves, by obtaining the corresponding first slope of each first truncated curve and selecting the first truncated curve corresponding to the largest first slope as the rising frequency curve, since the turning points in the frequency response curve are usually the key nodes of signal change, they can reflect the obvious changes in the response of the system, and these turning points often correspond to the positions where the characteristics of the object change greatly, by truncating the curve and focusing on these turning points, the key response of the system can be captured more accurately, the interference of noise and low-frequency parts can be avoided, and the measurement accuracy can be improved. Selecting the truncated curve with the largest slope as the rising frequency curve can make The system focuses on the area with the strongest response. The maximum slope usually means the part of the system that changes most dramatically, which is crucial for identifying the distance change between the object surface and the sensor. It can provide higher resolution and sensitivity and reduce measurement errors. The turning points in the frequency response curve often correspond to areas where the signal changes rapidly. By truncating the curve and selecting the rising part corresponding to the maximum slope, the influence of low-frequency or inconspicuous changes in the frequency response caused by noise, environmental changes or surface irregularities can be effectively eliminated. This can effectively reduce measurement errors and avoid errors introduced by signal fluctuations. By selecting the truncated curve with the maximum slope as the rising frequency curve, the area with the strongest reaction caused by the distance change on the object surface can be effectively identified.This method plays an important role in solving the errors caused by surface irregularities or changes in reflection angles in traditional laser measurement methods. In particular, when measuring the thickness of thermistor chips, by accurately identifying the rising frequency curve, it can reduce the errors caused by surface scattering or reflection fluctuations, and thus deduce a more accurate thickness dimension.

[0027] In one embodiment, the step S5 of obtaining the inductance value according to the impedance characteristic and obtaining the relative magnetic permeability according to the inductance value includes: S51, obtaining complex impedance and impedance resistance according to the impedance characteristics; S52, obtaining reaction impedance according to the complex impedance and impedance resistance; S53, obtaining the response frequency and size characteristics of the thermistor chip under a preset magnetic field; S54, obtaining an angular frequency according to the reaction frequency, and obtaining an inductance value according to the angular frequency and the reaction impedance; S55, obtaining the cross-sectional area and path length of the thermistor chip in the preset magnetic field action area according to the size characteristics; S56, obtaining vacuum magnetic permeability, and calculating relative magnetic permeability according to the vacuum magnetic permeability, inductance, cross-sectional area and path length, wherein the calculation formula is: ; Where X(CD) is the relative permeability, D(GZ) is the inductance, L(JC) is the path length, Z(CD) is the vacuum permeability, and J(MJ) is the cross-sectional area.

[0028] As described in the above steps S51-S56, the present invention obtains complex impedance and impedance resistance through impedance characteristics, and obtains reactive impedance based on the complex impedance and impedance resistance, obtains the reactive frequency and size characteristics of the thermistor chip under a preset magnetic field, obtains the angular frequency based on the reactive frequency, and obtains the inductance value based on the angular frequency and reactive impedance, wherein the complex impedance is a complex number that describes the relationship between voltage and current in a circuit, and the complex impedance includes not only the resistance (real part) of the material or circuit, but also the reactive part (imaginary part), the impedance resistance is the real part of the complex impedance, that is, the resistance of the material or circuit to direct current, and the reactive impedance is the imaginary part of the complex impedance, which indicates the reactivity of the circuit or material to electromagnetic waves. Since the traditional laser reflection measurement method is greatly affected by surface smoothness, material reflectivity, angle change and environmental factors (such as temperature, humidity, etc.), it is easy to produce errors. For example, if the surface of the object is uneven or the reflection is uneven, the signal returned by the laser may be interfered, resulting in inaccurate measurement. By utilizing electromagnetic response characteristics, such as complex impedance and reactive impedance, these problems can be avoided. Relying on the electrical characteristics of the object rather than the physical morphology of the surface, more stable and reliable measurements can be provided. By obtaining the response frequency and angular frequency of the chip and combining it with the calculation of the inductance value, it can sensitively reflect slight changes in the chip size, making the thickness measurement more sensitive. Measuring by electrical impedance characteristics and inductance values ​​can avoid the influence of surface scattering and reflection, making the measurement process more stable and accurate. By combining multiple electromagnetic characteristics such as complex impedance, reactive impedance, and angular frequency to infer the thickness of the thermistor chip, more comprehensive physical property information can be provided than traditional laser measurement methods. This comprehensive analysis of multiple parameters can improve measurement accuracy and help obtain more accurate dimensional data in complex application scenarios. There is usually a clear physical relationship between the inductance value and the thickness size of the thermistor chip. By measuring the thickness of the thermistor chip under a preset magnetic field, The measurement of response frequency and inductance can stably extract the electrical characteristics related to the chip size, thereby ensuring the consistency of the measurement results. The cross-sectional area and path length of the thermistor chip in the preset magnetic field action area are obtained through size characteristics. The vacuum permeability is obtained and the relative permeability is calculated based on the vacuum permeability, inductance, cross-sectional area and path length. By calculating the permeability, the uncertainty caused by the surface optical characteristics is avoided. This is because electromagnetic measurement is insensitive to factors such as surface smoothness and transparency, so it can provide more stable and accurate measurement results. Through the interaction between the magnetic field and the thermistor chip, combined with the inductance value and other physical characteristics, the thickness of the chip can be more accurately calculated. Especially for the thermistor chip of tiny size, its thickness change often affects the inductance value and permeability. Therefore, there is a more direct relationship between the calculated permeability and the chip size, providing a higher precision thickness measurement.

[0029] In one embodiment, the step S6 of acquiring the magnetic flux density according to the magnetic field distribution characteristics comprises: S61, obtaining the reaction magnetic field strength at multiple positions of the thermistor chip according to the magnetic field distribution characteristics; S62, obtaining the corresponding chip reaction area according to each reaction magnetic field strength; S63, obtaining a corresponding magnetic susceptibility according to the area of ​​each chip reaction region, and obtaining a corresponding effective magnetic field strength according to each magnetic susceptibility and the corresponding reaction magnetic field strength; S64, obtaining an average effective magnetic field strength according to the multiple effective magnetic field strengths; S65, obtaining the relative magnetic permeability of the thermistor chip, and obtaining the magnetic flux density according to the relative magnetic permeability and the average effective magnetic field strength.

[0030] As described in the above steps S61-S65, the present invention obtains the reaction magnetic field strength of multiple positions of the thermistor chip through the magnetic field distribution characteristics, obtains the corresponding chip reaction area area according to each reaction magnetic field strength, obtains the corresponding magnetic susceptibility through each chip reaction area area, and obtains the corresponding effective magnetic field strength according to each magnetic susceptibility and the corresponding reaction magnetic field strength, wherein the reaction magnetic field strength refers to the magnetic field strength generated by the external electromagnetic field excitation reaction in the chip, the chip reaction area area refers to the area on the chip where the magnetic field causes the magnetic or electrical reaction, and the magnetic susceptibility refers to the magnetic field generated under the action of the external magnetic field. It is a measure of the ability of thermistor to measure the magnetic field distribution characteristics. The chip size data can be directly obtained through electromagnetic response, which is not affected by changes in surface characteristics, reflectivity and environmental factors. By obtaining the reaction magnetic field strength of multiple positions of the thermistor chip and calculating the effective magnetic field strength based on the magnetic susceptibility, more accurate chip size information can be obtained. The magnetic susceptibility is the magnetic response of a material in a magnetic field, and the effective magnetic field strength can reflect the magnetic properties and size characteristics of the material. Combining this information can more accurately calculate the thickness of the chip. Unlike laser measurement, magnetic field measurement can provide more detailed local response information. Thereby improving the overall measurement accuracy. Laser measurement usually assumes that light is reflected back to the sensor at a normal angle on the surface of the object. However, if the surface of the object has curvature, roughness or angle changes, this assumption may fail, resulting in errors in the reflected signal. By measuring the magnetic field distribution and response intensity, the influence of irregular surface morphology can be bypassed, starting directly from the electromagnetic response of the chip, and reducing the error caused by the unstable reflection path. By measuring the reaction magnetic field intensity of the chip at different positions, more uniform and comprehensive measurement data can be obtained, especially when the surface of the object is complex or there are multiple materials. The average effective magnetic field intensity and the relative magnetic permeability of the thermistor chip are obtained through multiple effective magnetic field intensities, and the magnetic flux density is obtained based on the relative magnetic permeability and the average effective magnetic field intensity. By using physical quantities such as magnetic field intensity and magnetic permeability for measurement, it is not affected by factors such as surface morphology and reflectivity, so the error in laser measurement can be reduced. Especially when dealing with irregular or poorly reflective objects, the magnetic flux density is calculated by magnetic field intensity and relative magnetic permeability. These physical quantities are less dependent on the environment and are relatively more stable, reducing the errors caused by surface optical properties, so the performance and reliability of the system can be effectively improved.

[0031] In one embodiment, the step S7 of obtaining the penetration depth according to the magnetic flux density, and obtaining the chip thickness according to the penetration depth, the chip magnetic response frequency and the relative magnetic permeability includes: S71, obtaining multiple central magnetic field intensities of the center position of the thermistor chip under a preset magnetic field within a preset time period; S72, obtaining a magnetic field change rate according to multiple center magnetic field intensities and a preset time period; S73, obtaining the current frequency according to the magnetic flux density and the magnetic field change rate; S74, obtaining the conductivity and relative magnetic permeability of the thermistor chip, and calculating the penetration depth according to the relative magnetic permeability, current frequency and conductivity, wherein the calculation formula is: ; Where, C(TS) represents the penetration depth, X(CD) represents the relative magnetic permeability, D(DL) represents the electrical conductivity, and D(LP) represents the current frequency; S75, calculating the chip thickness size according to the penetration depth, the chip magnetic response frequency and the relative magnetic permeability, wherein the calculation formula is: ; Among them, X(HC) represents the chip thickness, C(TS) represents the penetration depth, X(CD) represents the relative magnetic permeability, and G(ZP) represents the chip magnetic response frequency.

[0032] As described in the above steps S71-S75, the present invention obtains the magnetic field change rate through multiple central magnetic field intensities and preset time periods, and obtains the current frequency through magnetic flux density and magnetic field change rate, wherein the magnetic field change rate refers to the speed at which the magnetic field intensity changes over time. The method of inferring the current frequency through the magnetic field change rate does not rely on optical reflection, and therefore can avoid errors caused by changes in the environment or surface characteristics. By using the change in the magnetic field to infer the current frequency, the size or thickness change of the object can be more accurately reflected through precise changes in magnetic field intensity, especially in irregular surfaces or complex structures. This method has high robustness. By monitoring multiple central magnetic field intensities and time periods, more data points can be obtained, thereby performing a more accurate analysis of the change trend and further reducing errors. By measuring the size of the object through changes in magnetic field intensity, continuous monitoring in a dynamic environment can be achieved. By obtaining the conductivity and relative magnetic permeability of the thermistor chip, and calculating the penetration depth based on the relative magnetic permeability, current frequency and conductivity, wherein, , the principle of this formula originates from the electromagnetic wave effect generated by the interaction of the electric field and the magnetic field when the alternating current propagates in the conductor. For alternating current, the distribution of current is not only affected by conductivity, but also closely related to the magnetic properties of the material and the frequency of the signal. This is because conductivity is a measure of the material's ability to conduct current. The greater the conductivity, the easier it is for the current to flow in the material. The conductivity directly affects the attenuation of the current on the surface and inside. The greater the conductivity, the smaller the penetration depth. The greater the magnetic permeability, the stronger the magnetic field reaction generated by the current in the conductor, causing the current to decay more rapidly in the conductor, thereby reducing the penetration depth. The frequency of the alternating current determines the rate of change of the current. The higher the frequency, the faster the current changes, and the stronger the electromagnetic wave effect generated, resulting in a decrease in the penetration depth of the current in the conductor. In the chip conductor, as the frequency of the alternating current increases, the changing electromagnetic field generated by the current will cause eddy current effects inside the conductor, which causes the intensity of the current to gradually decay. Ultimately, the current only flows within a certain depth on the surface of the conductor. This depth is the penetration depth. The chip thickness size is calculated by the penetration depth, the chip magnetic response frequency, and the relative magnetic permeability. Among them, The principle of this formula is mainly based on the behavior of electromagnetic waves propagating in matter, because the propagation of electromagnetic waves in chip materials follows specific physical laws, including penetration depth, chip magnetic response frequency, magnetic permeability, etc. These physical parameters are interconnected through the basic formulas of electromagnetism, and the thickness of the chip directly affects these electromagnetic properties. Specifically, the chip magnetic response frequency refers to the frequency at which the energy absorption of the chip or other electromagnetic structure reaches the maximum value under external drive. The size and shape of the chip determine its chip magnetic response frequency. For an antenna, resonant cavity or other electromagnetic resonance structure, the thickness of the chip directly affects its chip magnetic response frequency. The magnetic response frequency is usually inversely proportional to the thickness, that is, a thinner chip will lead to a higher chip magnetic response frequency, while a thicker chip will reduce the chip magnetic response frequency. The penetration depth reflects the attenuation of electromagnetic waves in the chip conductor, and the chip magnetic response frequency is closely related to the propagation speed of electromagnetic waves and the chip geometry. By adjusting the magnetic permeability and the chip geometry, the resonance characteristics of electromagnetic waves can be controlled. The chip magnetic response frequency is usually affected by the chip thickness. The relationship between the chip magnetic response frequency and the penetration depth can be used to infer the chip thickness to ensure an effective resonance effect. Finally, by establishing the above calculation The mathematical model combined with actual measurement can accurately calculate the thickness of the chip. The penetration depth can be calculated by obtaining the conductivity, relative magnetic permeability and current frequency of the thermistor chip. These physical quantities are not affected by the surface optical properties and do not need to rely on the light reflectivity of the object surface. Therefore, this method can provide more stable and accurate measurement results on irregular surfaces, low-reflective objects or in different lighting environments. In the laser reflection method, if the surface of the object is uneven, contaminated, coated, light scattering and other factors exist, the reflected light intensity may produce errors, resulting in deviations in distance calculation and chip thickness estimation. By using conductivity and relative magnetic permeability These physical properties can provide a more direct and stable measurement method, reduce the interference of external environment and surface characteristics on the measurement results, and the combination of conductivity and relative magnetic permeability can more accurately describe the magnetic response characteristics of the thermistor chip material, and further accurately calculate the thickness of the chip through the penetration depth and the chip magnetic response frequency. Therefore, the thickness of the thermistor chip is calculated by combining physical quantities such as conductivity, relative magnetic permeability, current frequency and penetration depth, which can effectively avoid the error sources faced by the laser reflection method, especially under complex conditions such as irregular surface, poor optical properties, and dynamic environment, providing more accurate and stable measurement results.

[0033] The present application also provides a thermistor chip size automatic identification system based on PLC control, which is applied to a PLC control system, including: A first acquisition module is used to acquire magnetic field response data of the thermistor chip under a preset magnetic field, and acquire a magnetic field simulation signal according to the magnetic field response data; A conversion module, used for converting the magnetic field analog signal into a magnetic field digital signal through an analog-to-digital converter; An input module, used for inputting the magnetic field digital signal into a PLC control system to obtain a digitized magnetic field characteristic, wherein the digitized magnetic field characteristic includes an output signal characteristic, an impedance characteristic and a magnetic field distribution characteristic; A second acquisition module, used to acquire a reflection coefficient and a transmission coefficient according to the output signal characteristics, and to acquire a chip magnetic response frequency according to the reflection coefficient and the transmission coefficient; A third acquisition module, used to acquire an inductance value according to the impedance characteristic, and acquire a relative magnetic permeability according to the inductance value; A fourth acquisition module, used to acquire magnetic flux density according to the magnetic field distribution characteristics; The fifth acquisition module is used to acquire the penetration depth according to the magnetic flux density, and acquire the chip thickness size according to the penetration depth, the chip magnetic response frequency and the relative magnetic permeability.

[0034] In one embodiment, the third acquisition module includes: A first acquisition unit, configured to acquire complex impedance and impedance resistance according to the impedance characteristic; A second acquisition unit, used for acquiring a reaction impedance according to the complex impedance and the impedance resistance; A third acquisition unit is used to acquire the response frequency and size characteristics of the thermistor chip under a preset magnetic field; a fourth acquisition unit, configured to acquire an angular frequency according to the reaction frequency, and acquire an inductance value according to the angular frequency and the reaction impedance; A fifth acquisition unit, configured to acquire a cross-sectional area and a path length of the thermistor chip in a preset magnetic field action area according to the size feature; The sixth acquisition unit is used to acquire the vacuum magnetic permeability, and acquire the relative magnetic permeability according to the vacuum magnetic permeability, inductance, cross-sectional area and path length.

[0035] The present invention also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the steps of the above-mentioned method for automatically identifying the size of a thermistor chip based on PLC control are implemented.

[0036] The present invention also provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned method for automatically identifying the size of a thermistor chip based on PLC control are implemented.

[0037] Those of ordinary skill 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 provided in this application and used in the embodiments may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. By way of 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 (SSRSDRAM), 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), etc.

[0038] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, device, article or method including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, device, article or method. In the absence of further restrictions, an element defined by the sentence "includes a ..." does not exclude the presence of other identical elements in the process, device, article or method including the element.

[0039] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for automatically identifying the size of a thermistor chip based on PLC control, applied to a PLC control system, characterized in that: include: Acquire magnetic field response data of the thermistor chip under a preset magnetic field, and acquire a magnetic field simulation signal according to the magnetic field response data; Converting the magnetic field analog signal into a magnetic field digital signal through an analog-to-digital converter; Inputting the magnetic field digital signal into a PLC control system to obtain a digitized magnetic field characteristic, wherein the digitized magnetic field characteristic includes an output signal characteristic, an impedance characteristic, and a magnetic field distribution characteristic; Acquire a reflection coefficient and a transmission coefficient according to the output signal characteristics, and acquire a chip magnetic response frequency according to the reflection coefficient and the transmission coefficient; Acquire an inductance value according to the impedance characteristic, and acquire a relative magnetic permeability according to the inductance value; Acquiring magnetic flux density according to the magnetic field distribution characteristics; The penetration depth is obtained according to the magnetic flux density, and the chip thickness is obtained according to the penetration depth, the chip magnetic response frequency and the relative magnetic permeability.

2. The method for automatically identifying thermistor chip size based on PLC control according to claim 1, characterized in that: The step of obtaining a reflection coefficient and a transmission coefficient according to the output signal characteristics, and obtaining a chip magnetic response frequency according to the reflection coefficient and the transmission coefficient comprises: Acquire the time domain signal characteristics and phase characteristics of the thermistor chip under a preset magnetic field according to the output signal characteristics; Performing Fourier transformation on the time domain signal characteristics to obtain an amplitude spectrum; The reflection coefficient is calculated according to the amplitude spectrum and phase characteristics, wherein the calculation formula is: ； Among them, F(SX) represents the reflection coefficient, F(DP) represents the amplitude spectrum, and X(T) represents the phase characteristic; The transmission coefficient is calculated according to the reflection coefficient, wherein the calculation formula is: ； Where, T(SX) represents the transmission coefficient, and F(SX) represents the reflection coefficient; Acquire a rising frequency curve according to the reflection coefficient, and acquire a falling frequency curve according to the transmission coefficient; Obtaining a first frequency corresponding to each first connection point in the rising frequency curve, and obtaining a first mean frequency according to the plurality of first frequencies; Acquire a second frequency corresponding to each second connection point in the decreasing frequency curve, and acquire a second mean frequency according to the plurality of second frequencies; The chip magnetic response frequency is obtained according to the first mean frequency and the second mean frequency.

3. The method for automatically identifying thermistor chip size based on PLC control according to claim 2, characterized in that: The step of obtaining a rising frequency curve according to the reflection coefficient comprises: Obtaining a preset frequency table, wherein the preset frequency table includes a plurality of frequencies arranged in order of magnitude; Obtaining a first amplitude value corresponding to the reflection coefficient at each frequency in a preset frequency table; The frequency-amplitude coordinate axis is established with frequency as the X-axis and amplitude value as the Y-axis; Taking the first amplitude values ​​as first connection points, and connecting them sequentially through a curve and plotting them on the time-amplitude coordinate axis, to obtain a first frequency response curve; Acquire a plurality of first turning points of the first frequency response curve, and truncate the first frequency response curve according to the plurality of first turning points to obtain a plurality of first truncation curves; The first slope corresponding to each of the first truncation curves is obtained, and the first truncation curve corresponding to the largest first slope is selected as the rising frequency curve.

4. The method for automatically identifying thermistor chip size based on PLC control according to claim 1, characterized in that: The step of obtaining an inductance value according to the impedance characteristic, and obtaining a relative magnetic permeability according to the inductance value comprises: Acquire complex impedance and impedance resistance according to the impedance characteristics; Obtaining reaction impedance according to the complex impedance and impedance resistance; Obtain the response frequency and size characteristics of the thermistor chip under a preset magnetic field; Acquire an angular frequency according to the reaction frequency, and acquire an inductance value according to the angular frequency and the reaction impedance; Obtaining the cross-sectional area and path length of the thermistor chip in a preset magnetic field action area according to the size characteristics; The vacuum magnetic permeability is obtained, and the relative magnetic permeability is obtained according to the vacuum magnetic permeability, the inductance value, the cross-sectional area and the path length.

5. The method for automatically identifying thermistor chip size based on PLC control according to claim 1, characterized in that: The step of obtaining the magnetic flux density according to the magnetic field distribution characteristics comprises: Acquire the reaction magnetic field strength at multiple positions of the thermistor chip according to the magnetic field distribution characteristics; Obtaining the corresponding chip reaction region area according to each of the reaction magnetic field strengths; Obtaining a corresponding magnetic susceptibility according to the area of ​​each chip reaction region, and obtaining a corresponding effective magnetic field strength according to each magnetic susceptibility and the corresponding reaction magnetic field strength; Acquire an average effective magnetic field strength according to the multiple effective magnetic field strengths; The relative magnetic permeability of the thermistor chip is obtained, and the magnetic flux density is obtained according to the relative magnetic permeability and the average effective magnetic field strength.

6. The method for automatically identifying thermistor chip size based on PLC control according to claim 1, characterized in that: The step of obtaining the penetration depth according to the magnetic flux density, and obtaining the chip thickness according to the penetration depth, the chip magnetic response frequency and the relative magnetic permeability comprises: Acquire multiple central magnetic field intensities of the center position of the thermistor chip under a preset magnetic field within a preset time period; Obtaining a magnetic field change rate according to multiple center magnetic field intensities and a preset time period; Obtaining the current frequency according to the magnetic flux density and the magnetic field change rate; The conductivity and relative magnetic permeability of the thermistor chip are obtained, and the penetration depth is calculated according to the relative magnetic permeability, current frequency and conductivity, wherein the calculation formula is: ； Where, C(TS) represents the penetration depth, X(CD) represents the relative magnetic permeability, D(DL) represents the electrical conductivity, and D(LP) represents the current frequency; The chip thickness is calculated according to the penetration depth, the chip magnetic response frequency and the relative magnetic permeability, wherein the calculation formula is: ； Among them, X(HC) represents the chip thickness, C(TS) represents the penetration depth, X(CD) represents the relative magnetic permeability, and G(ZP) represents the chip magnetic response frequency.

7. A thermistor chip size automatic identification system based on PLC control, applied to PLC control system, characterized in that: include: A first acquisition module is used to acquire magnetic field response data of the thermistor chip under a preset magnetic field, and acquire a magnetic field simulation signal according to the magnetic field response data; A conversion module, used for converting the magnetic field analog signal into a magnetic field digital signal through an analog-to-digital converter; An input module, used for inputting the magnetic field digital signal into a PLC control system to obtain a digitized magnetic field characteristic, wherein the digitized magnetic field characteristic includes an output signal characteristic, an impedance characteristic and a magnetic field distribution characteristic; A second acquisition module, used to acquire a reflection coefficient and a transmission coefficient according to the output signal characteristics, and to acquire a chip magnetic response frequency according to the reflection coefficient and the transmission coefficient; A third acquisition module, used to acquire an inductance value according to the impedance characteristic, and acquire a relative magnetic permeability according to the inductance value; A fourth acquisition module, used to acquire magnetic flux density according to the magnetic field distribution characteristics; The fifth acquisition module is used to acquire the penetration depth according to the magnetic flux density, and acquire the chip thickness size according to the penetration depth, the chip magnetic response frequency and the relative magnetic permeability.

8. The automatic thermistor chip size identification system based on PLC control according to claim 7 is characterized in that: The third acquisition module includes: A first acquisition unit, configured to acquire complex impedance and impedance resistance according to the impedance characteristic; A second acquisition unit, used for acquiring a reaction impedance according to the complex impedance and the impedance resistance; A third acquisition unit is used to acquire the response frequency and size characteristics of the thermistor chip under a preset magnetic field; a fourth acquisition unit, configured to acquire an angular frequency according to the reaction frequency, and acquire an inductance value according to the angular frequency and the reaction impedance; A fifth acquisition unit, configured to acquire a cross-sectional area and a path length of the thermistor chip in a preset magnetic field action area according to the size feature; The sixth acquisition unit is used to acquire the vacuum magnetic permeability, and acquire the relative magnetic permeability according to the vacuum magnetic permeability, inductance, cross-sectional area and path length.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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