Automatic temperature compensation method and apparatus, and storage medium

Abstract

An automatic temperature compensation method and apparatus, and a storage medium. The method comprises: acquiring an impedance information set of at least one position on an object under test; on the basis of a first impedance signal, n preset offsets and a pre-acquired reference signal, determining n error values corresponding to the first impedance signal; on the basis of the n error values and a preset standard, determining a final error value, such that different offsets corresponding to different temperature changes can be determined, so as to determine an accurate final compensation value for the current object under test; on the basis of an offset and the first impedance signal, determining a horizontally compensated impedance signal, so as to complete the compensation for an impedance signal in the horizontal aspect; and on the basis of the reference signal, the horizontally compensated impedance signal and a temperature deviation coefficient, determining a vertically compensated impedance signal.

Description

Automatic temperature compensation method, device and storage medium

[0001] Related applications

[0002] This application claims priority to Chinese patent application No. 202311632091.6 filed on December 1, 2023, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the technical field of structural health monitoring, and in particular to an automated temperature compensation method, device, and storage medium. Background Art

[0004] Piezoresistive impedance technology monitors the safety of structures and changes in damage status information by detecting changes in the impedance signal of the object to be measured. It has a high sensitivity for monitoring early minor damage to structures.

[0005] However, as the actual ambient temperature continues to change, the amplitude and horizontal frequency of the impedance signal will change significantly, resulting in the impedance signal changes caused by changes in the structural damage state may be submerged in the impedance signal changes caused by temperature changes, thereby causing the results of structural safety status monitoring to be interfered with, inaccurate, or even cause misjudgment.

[0006] Most existing technologies use the effective frequency shift method for temperature compensation. However, this technology rarely considers the frequency difference of amplitude deviation, which limits the impedance compensation accuracy of the effective frequency shift method.

[0007] Summary of the Invention

[0008] In view of this, the present application provides an automated temperature compensation method, device, and storage medium to solve the problems in the above-mentioned background technology.

[0009] In a first aspect, the present application provides an automated temperature compensation method, the method comprising: obtaining an impedance signal set collected at at least one position of an object to be measured; determining n error values ​​corresponding to the first impedance signal based on a first impedance signal, n preset offsets, and a pre-acquired reference signal, the first impedance signal being any one of the impedance signal set collected at at least one position; determining a final error value based on the n error values ​​and a preset standard; determining a horizontal compensation impedance signal based on the offset corresponding to the final error value, the first impedance signal; determining a vertical compensation impedance signal based on the reference signal, the horizontal compensation impedance signal, and a temperature deviation coefficient, the temperature deviation coefficient being calculated based on the reference signal and the first impedance signal; calculating a mean square error value between at least one vertical compensation impedance signal and the reference signal; when a mean square error value of a vertical compensation impedance signal does not meet a preset condition, determining the position of the corresponding numerical compensation signal as a damage position; continuously monitoring the impedance signal at the damage position; and continuously monitoring the damage position based on the impedance signal.

[0010] In a second aspect, the present application provides an automated temperature compensation device, which is applied to a computer device, wherein the computer device includes: a memory and a processor, the memory and the processor are communicatively connected to each other, and computer instructions are stored in the memory, wherein the device includes: an acquisition module, used to acquire an impedance signal set collected at at least one position of the object to be measured; a first error determination module, used to determine n error values ​​corresponding to the first impedance signal based on the first impedance signal, n preset offsets and a pre-acquired reference signal, the first impedance signal being any one of the impedance signal sets collected at at least one position; a second error determination module, used to determine a final error value based on the n error values ​​and a preset standard; a first compensation signal determination module, used to determine a horizontal compensation impedance signal based on the offset corresponding to the final error value and the first impedance signal; a second compensation signal determination module, used to determine a vertical compensation impedance signal based on the reference signal, the horizontal compensation impedance signal and the temperature deviation coefficient, the temperature deviation coefficient being calculated based on the reference signal and the first impedance signal. The device is also used to: calculate the mean square error value between at least one vertical compensation impedance signal and the reference signal; when the mean square error value of the vertical compensation impedance signal does not meet the preset conditions, determine the position of the corresponding numerical compensation signal as the damage position; continuously monitor the impedance signal of the damage position; and continuously monitor the damage position according to the impedance signal of the damage position.

[0011] In a third aspect, the present application provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the automated temperature compensation method of the first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the specific implementation methods of the present application or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the specific implementation methods or the description of the prior art. Obviously, the drawings described below are some implementation methods of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0013] FIG1 is a flow chart of an automated temperature compensation method according to an embodiment of the present application;

[0014] FIG2 is a flow chart of an automated temperature compensation method according to an embodiment of the present application;

[0015] FIG3 is a flow chart of an automated temperature compensation method according to an embodiment of the present application;

[0016] FIG4 is a schematic diagram of an automated temperature compensation method according to an embodiment of the present application;

[0017] FIG5 is a schematic diagram of an automated temperature compensation method according to an embodiment of the present application;

[0018] FIG6 is a schematic diagram of an automated temperature compensation method according to an embodiment of the present application;

[0019] FIG7 is a schematic diagram of an automated temperature compensation method according to an embodiment of the present application;

[0020] FIG8 is a schematic diagram of an automated temperature compensation method according to an embodiment of the present application;

[0021] 9a and 9b are schematic diagrams of an automated temperature compensation method according to an embodiment of the present application;

[0022] 10a-10c are schematic diagrams of an automated temperature compensation method according to an embodiment of the present application;

[0023] FIG11 is a schematic diagram of an automated temperature compensation method according to an embodiment of the present application;

[0024] 12a-12c are schematic diagrams of an automated temperature compensation method according to an embodiment of the present application;

[0025] FIG13 is a block diagram of the structure of an automated temperature compensation device according to an embodiment of the present application;

[0026] FIG14 is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present application. DETAILED DESCRIPTION

[0027] To make the purpose, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings 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 those skilled in the art without making creative efforts shall fall within the scope of protection of this application.

[0028] According to an embodiment of the present application, an embodiment of an automated temperature compensation method is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0029] Piezoresistive impedance technology monitors the structural safety and damage status of an object by detecting changes in its impedance signal. It is highly sensitive to detecting early signs of minor structural damage, is simple to implement, and can be applied to complex structures. The required sensors are inexpensive, lightweight, and compact, with high conversion efficiency and excellent long-term stability. Therefore, piezoresistive impedance technology is considered one of the most promising nondestructive testing technologies for structural health monitoring.

[0030] In the application of structural damage monitoring based on EMI (piezoresistive impedance) technology, a very important problem is encountered: as the actual ambient temperature continues to change, the amplitude and horizontal frequency of the impedance signal will change significantly. As a result, the impedance signal changes caused by changes in the structural damage state may be submerged in the impedance signal changes caused by temperature changes, which in turn causes interference, inaccuracy, and even misjudgment of the structural safety status monitoring results. Therefore, compensating for the temperature effect of the measured impedance signal is of great significance to promoting the application of piezoresistive impedance technology in practical engineering.

[0031] To compensate for the temperature of piezoelectric impedance signals, scholars at home and abroad have proposed various temperature compensation techniques, such as those based on neural networks, linear fitting, and cointegration. Among them, the effective frequency shift method has been widely used due to its computational simplicity and concise principle. The effective frequency shift (EFS) method, based on the cross-correlation coefficient, performs overall translation compensation of the impedance signal in the horizontal direction by finding the frequency offset at which the cross-correlation coefficient is maximized. In the vertical direction, it compensates for the impedance signal's amplitude deviation based on the difference in average values. This is equivalent to providing equal amplitude compensation for the impedance signal at all frequencies. However, research has shown that the vertical amplitude deviation of the impedance signal caused by temperature varies with frequency, resulting in different error amplitude deviations in low-frequency and high-frequency ranges. Currently, research on temperature compensation based on the effective frequency shift method rarely considers the frequency variability of the amplitude deviation, limiting the accuracy of impedance compensation using the effective frequency shift method.

[0032] To address the above issues, an automated temperature compensation method is provided in this embodiment. FIG1 is a flow chart of the automated temperature compensation method according to this embodiment of the present application. The automated temperature compensation method in this embodiment of the present application can be applied to a multi-point damage monitoring system in a temperature-varying environment, wherein the multi-point damage monitoring system includes a multi-channel impedance measurement module and a microcontroller module.

[0033] The multi-channel impedance measurement module includes multiple monitoring channels, with piezoelectric sensors attached to multiple monitoring points on the object to be measured. Specifically, the module comprises an AD5933 impedance measurement chip, low-voltage multiplexers #1, #2, and #3, a calibration resistor network, a feedback resistor network, and a measurement channel network. The module implements impedance measurement using the AD5933 chip; low-voltage multiplexer #1 controls the switching of the calibration resistor network; low-voltage multiplexer #2 controls the switching of the feedback resistor network; and low-voltage multiplexer #3 controls the switching of multiple measurement channels, enabling impedance signal acquisition at multiple locations on the structure.

[0034] The microprocessor module, based on an STM32 chip, controls the impedance measurement module. By controlling low-voltage multiplexers #1 and #2, it selects the calibration resistor and feedback resistor used in the measurement. By controlling low-voltage multiplexer #3, it ultimately switches impedance signal acquisition at multiple point source locations within the structure.

[0035] As shown in FIG1 , the process of the automatic temperature compensation method includes the following steps:

[0036] Step S101, obtaining an impedance signal set collected at at least one position of the object to be measured;

[0037] Step S102 : determining n error values ​​corresponding to the first impedance signal according to the first impedance signal, n preset offsets, and a pre-acquired reference signal.

[0038] The first impedance signal is any one of a set of impedance signals collected from at least one position.

[0039] Exemplarily, a multi-channel impedance measurement module acquires an impedance signal set corresponding to at least one location on the subject to be measured. After acquiring the impedance signal set, temperature compensation is performed to mitigate the effects of temperature fluctuations in the subject's environment. The reference signal is the impedance signal of the subject in a healthy state.

[0040] First, the impedance signal needs to be level compensated. Specifically, by calculating the impedance signal with different frequency offsets Δω i The impedance signal S after temperature change t (Δω i ) and the initial reference impedance signal S 0 The CC value (error value) between them.

[0041] Step S103: determining a final error value according to the n error values ​​and a preset standard.

[0042] Exemplarily, the frequency offset Δω when the CC calculation value is maximum (max CC) is selected to perform horizontal frequency offset compensation.

[0043] Among them, the frequency offset Δω is determined by the following calculation formula: Δω n =n×Δf,n=1,2,…,m

[0044] Wherein, Δf represents the frequency sweep step length, which is the frequency sweep step length corresponding to the impedance signal collected.

[0045] Step S104 : determining a horizontal compensation impedance signal according to the offset corresponding to the final error value and the first impedance signal.

[0046] For example, after determining the final error value, the horizontal compensation impedance signal is determined according to the offset corresponding to the final error value and the first impedance signal. Specifically, when the ambient temperature changes ΔT, the impedance data S after horizontal frequency shift compensation is T The revised form is as follows: S T =S t (ω+sgn(ΔT)×Δω)

[0047] Among them, S T is the horizontal compensation impedance signal, S tis the first impedance signal, ΔT is the temperature change value, and Δω is the offset corresponding to the final error value.

[0048] Step S105 , determining a vertical compensation impedance signal according to the reference signal, the horizontal compensation impedance signal, and a temperature deviation coefficient, wherein the temperature deviation coefficient is calculated according to the reference signal and the first impedance signal.

[0049] Exemplarily, after determining the horizontal compensation impedance signal, the vertical compensation impedance signal is determined based on the horizontal compensation impedance signal, the reference signal, and the temperature deviation coefficient, wherein the vertical compensation impedance signal is the value closest to the true impedance signal, wherein the vertical compensation signal takes into account the impact of temperature changes on the impedance signal, as well as the impact on frequency amplitude, thereby improving the accuracy of the impedance signal, and thereby improving the accuracy of the judgment of the degree of damage to the object to be measured.

[0050] Among them, the temperature deviation compensation coefficient is selected as the amplitude deviation rate signal S TR The average value of TR parameter, among which, electromechanical complex admittance The expression is as follows:

[0051] Where ω represents the angular frequency; w a , l a and h a are the width, length and thickness of the piezoelectric sensor respectively; represents the complex dielectric constant of the piezoelectric sensor under constant stress; Z a and Z s Represent the mechanical impedance of the piezoelectric sensor and the main structure respectively; d 31 represents the piezoelectric strain constant; represents the complex Young's modulus of the piezoelectric sensor under a constant electric field; κ is the wave number (κ=ω / c E t );c E t is the wave velocity; G and B represent admittance The real and imaginary parts of .

[0052] Mark as follows:

[0053] The electromechanical complex admittance It can be written as:

[0054] That is, the temperature affects the deviation rate signal S TR for:

[0055] in, is the electromechanical complex admittance after temperature change, is the electromechanical complex admittance under the reference state, and S TR The expression is visible, and its variables are C and C'.

[0056] Mark the symbols as follows:

[0057] To prove that the amplitude deviation rate signal S TR The rationality of using the average value of S as the compensation TR value only needs to be proved TR If it does not change with frequency or changes very little with frequency, it can be proved that taking its average value in the frequency domain as the compensation TR value has no error or has very little error, that is, it needs to be proved that:

[0058] According to mathematical knowledge:

[0059] The influencing variables of C include w a , l a , h a , d 31 , so we can get:

[0060] Analytically, the physical size of the piezoelectric sensor is w a , l a and h a It is independent of the frequency ω, that is for in Impedance of the main structure of a rectangular parallelepiped It can be seen from the expression that both are inverse proportional functions of frequency ω, so It has nothing to do with the angular frequency ω, that is When κl a =(ω×l a ) / c E t When the value is small, that is, the frequency ω or the sensor length l a Small, then (tanκl a / κl a )≈1, which can be regarded as not changing with frequency Complex dielectric constant of piezoelectric sensors Complex Young's modulus and strain constant d 31 These are inherent properties of the material and do not change with external excitation frequency.

[0061] In summary, when the frequency ω or the sensor length l a Smaller and satisfy (tanκl a / κl a )≈1, there is The same logic can be used to prove Substituting it into formula (5.20) we can get:

[0062] So far, it has been proved that the amplitude deviation rate signal S TR The average value is used as the rationality of the initial value of the compensation TR parameter.

[0063] The automated temperature compensation method provided in this embodiment obtains an impedance information set collected at at least one position of the object to be tested; determines n error values ​​of the first impedance signal object based on the first impedance signal, n preset offsets, and a pre-acquired reference signal; determines a final error value based on the n error values ​​and a preset standard, thereby determining different offsets corresponding to different temperature changes and determining an accurate final compensation value for the current object to be tested; on this basis, determines a horizontal compensation impedance signal based on the offset corresponding to the final error value and the first impedance signal, completing the horizontal compensation of the impedance signal; next, determines a vertical compensation impedance signal based on the reference signal, the horizontal compensation impedance signal, and the temperature deviation coefficient, performs differentiated compensation on the vertical amplitude, and improves the accuracy of the impedance signal.

[0064] In this embodiment, an automated temperature compensation method is provided. FIG2 is a flowchart of a forward search in the automated temperature compensation method according to an embodiment of the present application. The flow includes the following steps:

[0065] Step S106: Calculate a mean square error between at least one vertical compensation impedance signal and a reference signal.

[0066] Step S107 : When the mean square error value of the vertical compensation impedance signal does not meet a preset condition, the position of the corresponding numerical compensation signal is determined to be a damage position.

[0067] For example, after compensating the collected impedance signal, by calculating the root mean square difference between it and the reference signal, the position of the object to be measured that is damaged can be accurately determined based on the value of the root mean square difference, and then the corresponding countermeasures can be determined subsequently.

[0068] The calculation formula of the root mean square deviation (RMSD) is as follows:

[0069] Among them S i,ref represents the reference impedance signal of the i-th monitoring point, S i,x It represents the impedance signal collected at the i-th monitoring point when the damage degree is x, where x represents different damage degrees.

[0070] In one embodiment, the method further comprises:

[0071] Continuously monitor the impedance signal at the damage location;

[0072] The damage location is continuously monitored based on the impedance signal at the damage location.

[0073] For example, after determining the damage location, the location of early minor damage can be identified based on the damage location, and the RMSD value changes of the damaged area can be continuously monitored. By continuously monitoring the changes in the RMSD of the damaged area, the relative looseness of the bolt from the occurrence of initial damage to complete loosening and detachment can be monitored.

[0074] In this embodiment, an automated temperature compensation method is provided. FIG3 is a flowchart of a forward search in the automated temperature compensation method according to an embodiment of the present application. The flow includes the following steps:

[0075] Step S301: Obtain an impedance signal set collected at at least one position of the object to be measured. Please refer to step S101 of the embodiment shown in FIG1 for details, which will not be repeated here.

[0076] Step S302 : determining n error values ​​corresponding to the first impedance signal according to the first impedance signal, n preset offsets, and a pre-acquired reference signal, where the first impedance signal is any one of an impedance signal set collected from at least one position.

[0077] Wherein, the first impedance signal and the reference signal both include m frequency points. Specifically, the above step S302 includes:

[0078] Step S3021: Determine a second impedance signal according to the first impedance signal and the first offset.

[0079] The first offset is any one of the preset n offsets;

[0080] Exemplarily, the collected impedance signals are respectively calculated with the corresponding n offsets to obtain corresponding n second impedance signals, where the n second impedance signals simulate impedance signals that are compensated for frequency shift offsets at different levels.

[0081] Step S3022, determining a first statistical parameter of the second impedance signal according to each frequency point in the second impedance signal;

[0082] Step S3023, determining a second statistical parameter of the reference signal according to each frequency point in the reference signal;

[0083] Exemplarily, when collecting the impedance signal and the reference signal, there are m frequency points for collection. Therefore, the first statistical parameter of the second impedance signal and the second statistical parameter of the reference signal can be determined based on the impedance signal collected at each frequency point, where the first statistical parameter is the standard deviation and the average value, and the second statistical parameter is the standard deviation and the average value.

[0084] The average value of the second impedance signal is:

[0085] in, represents the impedance signal at the i-th frequency point after temperature changes, It represents the average value of the impedance signal after temperature changes, and m is the number of frequency points.

[0086] The average value of the reference signal is:

[0087] Among them, S i 0 It represents the impedance signal at the i-th frequency point at the reference temperature, It represents the average value of the impedance signal at the reference temperature, and m is the number of frequency points.

[0088] Step S3024 , determining a first error value according to the impedance signal at the ith frequency point corresponding to the second impedance signal, the impedance signal at the ith frequency point corresponding to the reference signal, the first statistical parameter, and the second statistical parameter.

[0089] Exemplarily, the first error value is calculated using the following formula:

[0090] Where m is the number of frequency points, represents the impedance signal at the i-th frequency point after temperature changes, Indicates the average value of the impedance signal after temperature changes, S i 0 It represents the impedance signal at the i-th frequency point at the reference temperature, represents the average value of the impedance signal at the reference temperature, σ1 represents the standard deviation of the impedance signal after temperature change, σ0 represents the standard deviation of the impedance signal at the reference temperature, CC(S T ,S 0 ) is the first error value.

[0091] Step S303, determining a final error value based on the n error values ​​and a preset standard;

[0092] Step S304 : determining a horizontal compensation impedance signal according to the offset corresponding to the final error value and the first impedance signal.

[0093] Step S305 , determining a vertical compensation impedance signal according to the reference signal, the horizontal compensation impedance signal, and a temperature deviation coefficient, wherein the temperature deviation coefficient is calculated according to the reference signal and the first impedance signal.

[0094] The above step S305 includes:

[0095] Step S3051, determining an impedance change value according to the first average value and the second average value;

[0096] Step S3052: determining a vertical compensation impedance signal according to the reference signal, the first average value, the horizontal compensation impedance signal, the impedance change value, and the temperature deviation coefficient.

[0097] Exemplarily, the corresponding impedance change value is determined by the following formula:

[0098] The vertical compensation impedance signal is calculated using the following formula:

[0099] Among them, S 0 is the reference signal, is the first average value, TR is the temperature deviation coefficient, S T is the horizontal compensation signal, and ΔS is the impedance change value.

[0100] The temperature deviation coefficient is determined according to the following steps: determining an initial temperature deviation coefficient according to a reference signal, a horizontal compensation impedance signal, and the number of frequency points; and optimizing the initial temperature deviation coefficient to determine a final temperature deviation coefficient.

[0101] Exemplarily, the initial temperature deviation coefficient is determined according to the amplitude deviation between the horizontal compensation impedance signal and the reference signal. Specifically,

[0102] Among them, S TR is the amplitude deviation rate signal.

[0103] In one embodiment, optimizing the initial temperature deviation coefficient to determine the final temperature deviation coefficient specifically includes:

[0104] Step a1, determining the first temperature deviation coefficient and the second temperature deviation coefficient according to the initial temperature deviation coefficient, the first preset random number and the second preset random number, the first temperature deviation coefficient is smaller than the initial temperature deviation coefficient and the second temperature deviation coefficient, and the first preset random number is smaller than the second preset random number.

[0105] Step a2: determining a first relative error value corresponding to the initial temperature deviation coefficient, a second relative error value corresponding to the first temperature deviation coefficient, and a third relative error value corresponding to the second temperature deviation coefficient.

[0106] For example, based on the initial value TR0, an iterative search is performed on a suitable value of the temperature influence deviation rate coefficient TR, and the steps are as follows:

[0107] Step 1: Initialization.

[0108] Generate random numbers C1∈[-1,0), C2∈(0,1]

[0109] t1=TR0+C1,e1=f(t1)

[0110] t2=TR0,e2=f(t2)

[0111] t3=TR0+C2,e2=f(t3)

[0112] Wherein, f represents a relative error function with reference to the reference impedance signal, C1 is a first preset random number, C2 is a second preset random number, and TR0 is an initial temperature deviation coefficient. e1, e2, and e3 are the first relative error value, the second relative error value, and the third relative error value, respectively.

[0113] Step a3, determining a first gradient value according to the first relative error value, the second relative error value, and a first preset random number;

[0114] Step a4, determining a second gradient value according to the second relative error value, the third relative error value, and a second preset random number;

[0115] Step 2: Calculate the travel gradient.

[0116] g1 is the first gradient value, g2 is the second gradient value, f1 is the first relative error value, f2 is the second relative error value, f3 is the third relative error value, C1 is the first preset random number, and C2 is the second preset random number.

[0117] Step a5: performing iterative optimization based on the first gradient value and the second gradient value to determine a final temperature deviation coefficient.

[0118] Step 3: Determine the sign of the moving gradient

[0119] If f1>0,f2<0

[0120] t1=t2, t2=t3, e1=f(t1), e2=f(t2)

[0121] C2∈(0,1]

[0122] t3=t3+C2

[0123] Update f2 and iterate until f2>0 (how to understand these)

[0124] Output TR = t2

[0125] ElseIf f1>0,f2>0

[0126] Compare the absolute values ​​of f1 and f2

[0127] If f1 <f2,

[0128] C1=-C1 2

[0129] t3=t2, t2=t2+C1, e3=f(t3), e2=f(t2)

[0130] Update C1 value and iterate until f2 < 0

[0131] Output TR = x3

[0132] ElseIf f1>f2,

[0133] C2=C2 2

[0134] t1=t2, t2=t2+C2, e1=f(t1), e2=f(t2)

[0135] Update C2 value and iterate until f1 < 0

[0136] Output TR = x1

[0137] ElseIf f1<0,f2>0

[0138] t3=t2, t2=t1, e3=f(t3), e2=f(t2)

[0139] C1∈[-1,0)

[0140] t1=t1+C1

[0141] Update f1 and iterate until f1>0

[0142] Output TR = t2

[0143] The second-order partial derivative of the curve of temperature compensation error changing with TR parameter is strictly greater than 0. There is no situation where (f1-f2) / c1<0 and (f3-f2) / c2<0. Therefore, this situation is not discussed in the iterative search.

[0144] The method introduced in the above example and the multi-point damage monitoring system for a temperature-varying environment to which the method is applicable are shown in FIG4 , including an effective frequency shift automatic temperature compensation algorithm (automatic temperature compensation algorithm), a structural multi-point impedance acquisition system (multi-point damage monitoring system), and a piezoresistive impedance structural multi-point damage monitoring method.

[0145] Among them, the multi-point structural impedance acquisition system has multiple monitoring channels. By attaching piezoelectric sensors to multiple monitoring points of the structure, the multi-point impedance acquisition system can realize impedance signal acquisition at multiple point source positions of the structure.

[0146] The improved effective frequency shift automatic temperature compensation algorithm can realize automatic temperature compensation of the impedance signal collected by the multi-point impedance collection system of the structure by improving the vertical amplitude deviation compensation.

[0147] The method for locating multi-point damage in a piezoelectric impedance structure analyzes the impedance signal acquired by the multi-point impedance acquisition system of the structure and identifies the location of the damage based on the root mean square deviation (RMSD) between the impedance signal and a reference signal.

[0148] The effective frequency shift automatic temperature compensation algorithm, based on the innovatively proposed temperature influence deviation rate TR parameter, can realize the vertical amplitude deviation frequency differential compensation of the impedance signal; by deriving the initial value formula of the TR parameter and combining it with the local optimization strategy, the TR parameter can be automatically determined.

[0149] Next, two examples are used to verify and analyze the feasibility and accuracy of the above implementation method.

[0150] Example 1:

[0151] In the field of structural health monitoring, when using the piezoresistive impedance method for damage monitoring, a piezoelectric ceramic transducer (PZT) is generally first attached to the object to be monitored, and then the PZT is connected to an impedance measurement device. After the impedance signal is acquired using the impedance measurement device, the temperature effect of the impedance signal is first eliminated based on a specific temperature compensation algorithm. Then, structural damage is identified by analyzing the RMSD value changes of the impedance signal. Among them, the effect of temperature compensation directly affects the results of damage identification and is of great significance.

[0152] The traditional effective frequency shift method can be used to compensate for impedance signals in two ways: horizontal frequency shift compensation and amplitude deviation compensation. The appropriate frequency offset is determined by calculating the maximum correlation coefficient between the impedance signal and the reference signal, and then the impedance signal is subjected to an overall frequency shift to achieve horizontal frequency shift compensation. On the basis of horizontal frequency shift compensation, the impedance signal is further mean-adjusted and normalized to achieve amplitude deviation compensation. Amplitude deviation compensation based on mean adjustment and normalization is equivalent to performing equal amplitude compensation on the impedance signal at all frequencies. The impedance amplitude deviation caused by temperature at different frequencies is different, and the absolute value of the amplitude deviation is related to the numerical distance between the signal modulus and the average value; this inference indicates that the conventional effective frequency shift method is inappropriate for performing equal amplitude compensation on the impedance signal at all frequencies. In order to perform differential amplitude deviation compensation for all frequencies, this chapter improves the amplitude deviation compensation of the existing EFS method, proposes a temperature-affected deviation rate parameter, and performs differential amplitude deviation frequency compensation on the impedance signal based on this parameter.

[0153] In order to test the temperature compensation performance and damage identification performance improvement effects of the automated temperature compensation algorithm and conventional effective frequency shift method proposed in this application in long-term monitoring of temperature-varying environments, as shown in Figure 5, in this embodiment, an impedance signal monitoring test was conducted on the flange structure and the bolts thereon in an outdoor temperature-varying environment. The outdoor test consisted of two parts: a temperature compensation performance verification test and a damage identification performance improvement test. The temperature compensation performance verification test took the monitoring of one of the bolts as an example. In the damage identification performance improvement experiment, all bolts were monitored, wherein the bolt loosening damage was loaded on one of the bolts. Impedance measurement was performed using the structural multi-point impedance acquisition system provided in this application. The temperature was measured using a TH40W temperature monitoring recorder with a temperature resolution of 0.1°C. The monitoring test was performed in an outdoor environment at No. 40, Hongshan Side Road, Wuchang District, Wuhan City, Hubei Province, China.

[0154] (1) Temperature compensation performance verification test

[0155] An 11-day temperature compensation performance verification test was conducted from 2022-11-29-03:40 to 2022-12-10:08:00. Impedance and temperature data were synchronously collected and recorded, and the impedance signal was temperature compensated using the conventional effective frequency shift method and the improved effective frequency shift automated temperature compensation algorithm proposed in this application.

[0156] Before the monitoring test began, a torque wrench was used to control the torque of all bolts to 30 N·m. The PZT sheets attached to the bolts were then scanned over a wide frequency range from 10 Hz to 100 kHz. Based on the frequency location of a significant resonant peak in the impedance modulus curve, a frequency range of 75 kHz to 100 kHz was selected. Impedance calibration and monitoring were performed using a 1 kΩ calibration resistor.

[0157] In order to compare the temperature compensation effect of the method proposed in this application, the impedance signal at 11-29 03:40 (12.8℃) is used as the benchmark data (hereinafter referred to as the benchmark data at this moment), and the improved effective frequency shift automatic temperature compensation algorithm is used to perform temperature compensation on the impedance signal obtained by subsequent monitoring. At the same time, the conventional effective frequency shift method is used to perform temperature compensation on the impedance signals collected at different times. Finally, with the benchmark data as a reference, the relative errors of the two methods for the compensation of impedance data at different times are calculated respectively. The average relative errors of the temperature compensation of all monitoring moments of the two methods are statistically analyzed. The average relative errors of the improved effective frequency shift method and the conventional effective frequency shift method are 0.26% and 0.44% respectively, and the standard deviations of the relative errors are 0.017% and 0.097% respectively. It can be seen that compared with the conventional effective frequency shift method, the improved effective frequency shift method can more effectively eliminate the influence of temperature on the impedance measurement results of the measurement system developed in this article, and achieve better temperature compensation accuracy and error stability.

[0158] [Corrected 14.10.2024 in accordance with Rule 91] The compensation errors of the two methods at different times were compared, and the comparison results are shown in the scatter plot in Figure 6. The maximum temperature during the monitoring period was 12.8°C, and the minimum temperature was 1.6°C. The ambient temperature changes during the test are shown by the solid line in Figure 6. The average relative error of the conventional method fluctuates significantly over time and is approximately negatively correlated with temperature changes (error increases when temperature decreases, and decreases when temperature increases). The scatter plot (RE-ΔT) of the compensation errors of the two methods versus the temperature difference (ΔT) is further calculated and compared, with ΔT calculated as a reference temperature of 12.8°C. The results are shown in Figure 7. The figure clearly shows that the compensation error of the conventional method increases with increasing ΔT, while the method in this embodiment shows little change with ΔT. This may be because the conventional effective frequency shift method relies solely on mean adjustment and normalization to compensate for the impedance amplitude after temperature changes, which is equivalent to applying the same vertical amplitude compensation to all frequency points. However, it was observed in the experiment of Example 2 that the impedance amplitude deviations at different frequencies caused by temperature changes are different. In addition, as the temperature gap gradually increases, this amplitude deviation will continue to increase. Therefore, the compensation error of the conventional effective frequency shift method will increase with the increase of the temperature difference. In comparison, the method proposed in the present application performs amplitude compensation of impedance signals of different frequencies with different numerical values ​​based on the proposed temperature influence deviation rate parameter. When the temperature difference increases and thereby causes the amplitude deviation of impedance signals of different frequencies to increase, the method of the present application can still achieve appropriate numerical compensation. It can be seen that compared to the conventional effective frequency shift method, the improved effective frequency shift automatic temperature compensation algorithm proposed in the present application has a more stable temperature compensation performance, regardless of whether it changes over time or with temperature difference.

[0159] In addition, to visually compare the difference in compensation effects, we visually compare the compensation effects of the two methods at 12-05-10:10 (5.3°C) in Figure 7. At this time, the compensation errors of the two methods are 0.498% and 0.271%, respectively. The compensation effect comparison is shown in Figure 8. Compared with the conventional effective frequency shift method, the improved effective frequency shift method proposed in this application can measure an impedance signal that is more consistent with the reference signal and well preserves the characteristics of the impedance signal (resonance peak), without any structural damage changes.

[0160] (2) Damage identification performance improvement test

[0161] In order to test the effectiveness of the proposed improved effective frequency shift method in improving damage identification performance under temperature fluctuations, this section conducted a temperature compensation-based damage identification monitoring test during the period of significant temperature fluctuations on the 11th day of monitoring (12-10 20:40 to 12-11 00:30). During the test, a torque wrench was used to apply 0N·m, 10N·m, and 20N·m bolt loosening damage to the flange structure bolts under temperature conditions of 10.6℃, 9.6℃, 8.5℃, 7.4℃, and 6.5℃, respectively. The developed system was used to collect the corresponding impedance signals. The impedance signals were then temperature compensated using the improved effective frequency shift automated temperature compensation algorithm proposed in this application and the conventional effective frequency shift method. To demonstrate the compensation effect, we visualized the compensation effect for one of the working conditions (10.6°C), as shown in Figures 9a and 9b. By comparing the impedance signals before and after compensation, we can see that the method proposed in this chapter can effectively eliminate the temperature effect in the impedance signal and well preserve the damage characteristics in the signal, such as the resonant peak between 95kHz and 100kHz under the 0N·m working condition.

[0162] Then, using the benchmark data (11-29 03:40 (12.8°C)) as a reference, the RMSD values ​​of different loosening damage under various temperature conditions were calculated for the impedance curve without temperature compensation, the impedance curve using the conventional effective frequency shift method for temperature compensation, and the impedance curve after compensation using the improved effective frequency shift automated temperature compensation algorithm proposed in this application. The calculation results are shown in Figures 10a-10c. Figure 10a shows the RMSD result calculated for the original data (uncompensated), Figure 10b shows the RMSD result calculated for the data after temperature compensation using the conventional effective frequency shift method, and Figure 10c shows the RMSD result calculated for the data after temperature compensation using the improved effective frequency shift method proposed in this chapter. The dotted lines in the figure are the RMSD change trajectory lines. The blue line indicates that the change in the RMSD value can effectively identify the change in the torque of the measured bolt, that is, the RMSD value gradually decreases with increasing torque; the yellow line indicates that the change in the impedance signal caused by the torque change is submerged in the influence of temperature, and the RMSD cannot reveal the change in the bolt torque. The red line indicates that RMSD incorrectly identifies the torque change. Affected by temperature, the numerical change of RMSD is inconsistent with the change pattern of torque loosening.

[0163] As can be seen from Figure 10a, only under the 10.6℃ working condition, which is closest to the baseline working condition (12.8℃), the impedance signal without temperature compensation can effectively identify the bolt torque change. Under the other temperature conditions (9.6℃, 8.5℃, and 7.4℃), as the temperature difference increases, the damage information in the impedance signal is gradually submerged in the influence of temperature and even causes misidentification (6.5℃). As can be seen from Figure 10b, the impedance signal after temperature compensation using the conventional effective frequency shift method can effectively identify the bolt torque change under the temperature conditions of 10.6℃, 9.6℃, 8.5℃, and 7.4℃. The changes in bolt torque can be identified under temperature interference. However, errors occur in the identification of torque changes under the 6.5°C working condition with the largest temperature difference from the baseline working condition (12.8°C). This shows that the conventional effective frequency shift method can eliminate temperature interference to a certain extent, but the temperature compensation effect of this method will gradually attenuate as the temperature difference increases. As shown in Figure 10c, the impedance data after temperature compensation using the improved effective frequency shift automatic temperature compensation algorithm proposed in this application can effectively identify the changes in bolt torque through the numerical changes in RMSD under various temperature conditions. The comparative test results show that the improved effective frequency shift method temperature compensation proposed in this chapter has a wider range of applicability and can effectively improve the damage identification performance of piezoresistive impedance technology in temperature-varying environment monitoring applications.

[0164] Example 2:

[0165] This example conducted a high-temperature controlled test on an iron specimen shown in Figure 11. The impedance signal's behavior under temperature effects was analyzed to validate the proposed improvements. The impedance sweep frequency range was 75kHz to 100kHz, and the temperature range was 26°C to 56°C. Impedance data was collected at 2°C intervals. To ensure that the specimen temperature was consistent with the ambient temperature, a high-precision temperature recorder (TH40W) was used to monitor the structure's temperature. Impedance data was collected after the temperature stabilized for 12 minutes.

[0166] The impedance signal acquired during the impedance measurement is shown in Figure 12a. As the temperature increases, the impedance signal experiences a leftward frequency shift horizontally and a downward amplitude deviation vertically. Furthermore, as the temperature differential increases, the frequency shift and amplitude deviation increase.

[0167] The impedance signal collected at 26°C was used as the reference signal. The horizontal frequency shift compensation of the impedance signal was performed based on the maximum cross-correlation coefficient, and the result is shown in Figure 12b. Furthermore, the signal was mean-adjusted using the conventional effective frequency shift method, and the result is shown in Figure 12c.

[0168] As shown in Figure 12c, after equal amplitude compensation, the impedance signal and the reference signal still have amplitude deviations of different values ​​at different frequencies. The greater the temperature change, the greater the amplitude deviation. This phenomenon shows that the conventional effective frequency shift method still needs to compensate for the frequency difference of the amplitude deviation after the mean adjustment.

[0169] This embodiment also provides an automated temperature compensation device for implementing the above-mentioned embodiments and some implementations. Details already described will not be repeated here. As used below, the term "module" may refer to a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, implementation using hardware, or a combination of software and hardware, is also possible and contemplated.

[0170] This embodiment provides an automatic temperature compensation device, as shown in FIG13 , including:

[0171] An acquisition module 1301 is configured to acquire an impedance signal set collected from at least one position of the object to be measured;

[0172] a first error determination module 1302, configured to determine n error values ​​corresponding to a first impedance signal according to the first impedance signal, n preset offsets, and a pre-acquired reference signal, wherein the first impedance signal is any one of the impedance signal set collected at the at least one position;

[0173] A second error determination module 1303 is configured to determine a final error value based on the n error values ​​and a preset standard;

[0174] A first compensation signal determination module 1304 is configured to determine a horizontal compensation impedance signal according to the offset corresponding to the final error value and the first impedance signal; and

[0175] The second compensation signal determination module 1305 is configured to determine a vertical compensation impedance signal according to the reference signal, the horizontal compensation impedance signal, and a temperature deviation coefficient, wherein the temperature deviation coefficient is calculated according to the reference signal and the first impedance signal.

[0176] In some embodiments, the device is further used to: calculate the mean square error value between at least one vertical compensation impedance signal and the reference signal; and when the mean square error value of the vertical compensation impedance signal does not meet a preset condition, determine that the position of the corresponding numerical compensation signal is the damage position.

[0177] In some embodiments, the device is further configured to: continuously monitor the impedance signal at the damage location; and continuously monitor the damage location based on the impedance signal at the damage location.

[0178] In some embodiments, the first impedance signal and the reference signal both include m frequency points, and the first error determination module specifically includes:

[0179] an offset unit, configured to determine a second impedance signal according to the first impedance signal and a first offset, wherein the first offset is any one of the n preset offsets;

[0180] a first statistical unit, configured to determine a first statistical parameter of the second impedance signal according to each frequency point in the second impedance signal;

[0181] a second statistical unit, configured to determine a second statistical parameter of the reference signal according to each frequency point in the reference signal; and

[0182] An error unit is configured to determine a first error value based on the i-th frequency impedance signal corresponding to the second impedance signal, the i-th frequency impedance signal corresponding to the reference signal, the first statistical parameter, and the second statistical parameter.

[0183] In some embodiments, the first statistical parameter includes a first mean and a first standard deviation, and the second statistical parameter includes a second mean and a second standard deviation.

[0184] In some embodiments, the second compensation signal determination module specifically includes:

[0185] an impedance change determining unit, configured to determine an impedance change value according to the first average value and the second average value;

[0186] a vertical compensation unit, configured to determine the vertical compensation impedance signal according to the reference signal, the first average value, the horizontal compensation impedance signal, the impedance change value, and the temperature deviation coefficient;

[0187] The temperature deviation coefficient in the vertical compensation unit is determined according to the following steps:

[0188] determining an initial temperature deviation coefficient according to the reference signal, the horizontal compensation impedance signal, and the number of frequency points; and

[0189] The initial temperature deviation coefficient is optimized to determine the final temperature deviation coefficient.

[0190] In some embodiments, the second compensation signal determination module optimizes the initial temperature deviation coefficient to determine the final temperature deviation coefficient, specifically including:

[0191] a random number determination subunit, configured to determine a first temperature deviation coefficient and a second temperature deviation coefficient according to the initial temperature deviation coefficient, a first preset random number, and a second preset random number, wherein the first temperature deviation coefficient is smaller than the initial temperature deviation coefficient and smaller than the second temperature deviation coefficient, and the first preset random number is smaller than the second preset random number;

[0192] an error determination subunit, configured to respectively determine a first relative error value corresponding to the initial temperature deviation coefficient, a second relative error value corresponding to the first temperature deviation coefficient, and a third relative error value corresponding to the second temperature deviation coefficient;

[0193] a first gradient determining subunit, configured to determine a first gradient value according to the first relative error value, the second relative error value, and the first preset random number;

[0194] a second gradient determining subunit, configured to determine a second gradient value according to the second relative error value, the third relative error value, and the second preset random number; and

[0195] The coefficient determination unit is used to perform iterative optimization according to the first gradient value and the second gradient value to determine a final temperature deviation coefficient.

[0196] In some embodiments, the coefficient determination unit is specifically configured to: when the first gradient is greater than zero and the second gradient is less than zero, move the initial temperature deviation coefficient to the right on the numerical axis until the second gradient is greater than zero, and determine the final temperature deviation coefficient based on the initial temperature deviation coefficient and the right-shifted value;

[0197] When the first gradient is less than zero and the second gradient is greater than zero, the initial temperature deviation coefficient is shifted to the left on the numerical axis until the first gradient is greater than zero, and the final temperature deviation coefficient is determined based on the initial temperature deviation coefficient and the left-shifted value;

[0198] When the first gradient is greater than zero and the second gradient is greater than zero, and when the absolute value of the first gradient is less than the absolute value of the second gradient, updating the first preset random number and shifting the initial temperature deviation coefficient to the left on the number axis until the second gradient is less than zero, and determining the final temperature deviation coefficient based on the initial temperature deviation coefficient and the left-shifted value; and

[0199] When the first gradient is greater than zero and the second gradient is greater than zero, and when the absolute value of the first gradient is greater than the absolute value of the second gradient, the first preset random number is updated and the initial temperature deviation coefficient is moved to the right of the number axis until the second gradient is less than zero. The final temperature deviation coefficient is determined based on the initial temperature deviation coefficient and the shifted value.

[0200] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0201] The automated temperature compensation device in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0202] An embodiment of the present application also provides a computer device having the automatic temperature compensation device shown in FIG13 above.

[0203] Please refer to Figure 14, which is a schematic diagram of the structure of a computer device provided by some embodiments of the present application. As shown in Figure 14, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. The various components are connected to each other using different buses and can be installed on a common motherboard or installed in other ways as needed. The processor can process instructions executed within the computer device, including instructions stored in or on the memory to display graphical information of the GUI on an external input / output device (such as a display device coupled to the interface). In some embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 14 takes a processor 10 as an example.

[0204] The processor 10 may be a central processing unit, a network processor, or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be an application-specific integrated circuit, a programmable logic device, or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic, or any combination thereof.

[0205] The memory 20 stores instructions that can be executed by at least one processor 10, so as to enable at least one processor 10 to execute the method shown in the above embodiment.

[0206] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and application programs required for at least one function; the data storage area may store data created based on the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some embodiments, the memory 20 may optionally include a memory remotely located relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0207] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid-state drive; the memory 20 may also include a combination of the above types of memory.

[0208] The computer device further includes a communication interface 30 for the computer device to communicate with other devices or a communication network.

[0209] The embodiments of the present application also provide a computer-readable storage medium. The above-mentioned method according to the embodiment of the present application can be implemented in hardware, firmware, or implemented as a computer code that can be recorded in a storage medium, or implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and downloaded through a network and will be stored in a local storage medium, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state drive, etc.; further, the storage medium can also include a combination of the above-mentioned types of memory. It can be understood that a computer, a processor, a microprocessor controller or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor or hardware, the method shown in the above embodiment is implemented.

[0210] Although the embodiments of the present application have been described with reference to the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present application, and such modifications and variations shall fall within the scope defined by the appended claims.

Claims

1. An automated temperature compensation method, wherein: The method comprises: Acquire an impedance signal set collected at at least one position of the object to be measured; Determine n error values ​​corresponding to the first impedance signal according to the first impedance signal, the preset n offsets and the pre-acquired reference signal, wherein the first impedance signal is any one of the impedance signal sets collected at the at least one position; Determining a final error value according to the n error values ​​and a preset standard; Determine a horizontal compensation impedance signal according to the offset corresponding to the final error value and the first impedance signal; A vertical compensation impedance signal is determined according to the reference signal, the horizontal compensation impedance signal and a temperature deviation coefficient, wherein the temperature deviation coefficient is calculated according to the reference signal and the first impedance signal.

2. The method according to claim 1, wherein: The first impedance signal and the reference signal both include m frequency points, and determining n error values ​​corresponding to the first impedance signal according to the first impedance signal, n preset offsets, and a pre-acquired reference signal specifically includes: Determine a second impedance signal according to the first impedance signal and a first offset, wherein the first offset is any one of the preset n offsets; Determining a first statistical parameter of the second impedance signal according to each frequency point in the second impedance signal; Determining a second statistical parameter of the reference signal according to each frequency point in the reference signal; and A first error value is determined according to the i-th frequency point impedance signal corresponding to the second impedance signal, the i-th frequency point impedance signal corresponding to the reference signal, the first statistical parameter, and the second statistical parameter.

3. The method according to claim 2, wherein: The first statistical parameter includes a first mean value and a first standard deviation, and the second statistical parameter includes a second mean value and a second standard deviation.

4. The method according to claim 3, wherein: The step of determining the vertical compensation impedance signal according to the reference signal, the horizontal compensation impedance signal and the temperature deviation coefficient specifically includes: determining an impedance change value according to the first average value and the second average value; Determining the vertical compensation impedance signal according to the reference signal, the first average value, the horizontal compensation impedance signal, the impedance change value and the temperature deviation coefficient; The temperature deviation coefficient is determined according to the following steps: Determining an initial temperature deviation coefficient according to the reference signal, the horizontal compensation impedance signal, and the number of frequency points; and The initial temperature deviation coefficient is optimized to determine the final temperature deviation coefficient.

5. The method according to claim 4, wherein: The step of optimizing the initial temperature deviation coefficient to determine the final temperature deviation coefficient specifically includes: Determine a first temperature deviation coefficient and a second temperature deviation coefficient according to the initial temperature deviation coefficient, a first preset random number, and a second preset random number, wherein the first temperature deviation coefficient is smaller than the initial temperature deviation coefficient and smaller than the second temperature deviation coefficient, and the first preset random number is smaller than the second preset random number; Respectively determining a first relative error value corresponding to the initial temperature deviation coefficient, a second relative error value corresponding to the first temperature deviation coefficient, and a third relative error value corresponding to the second temperature deviation coefficient; Determine a first gradient value according to the first relative error value, the second relative error value, and the first preset random number; determining a second gradient value according to the second relative error value, the third relative error value, and the second preset random number; and An iterative optimization is performed according to the first gradient value and the second gradient value to determine a final temperature deviation coefficient.

6. The method according to claim 5, wherein: The iterative optimization according to the first gradient value and the second gradient value to determine the final temperature deviation coefficient specifically includes: When the first gradient is greater than zero and the second gradient is less than zero, the initial temperature deviation coefficient is moved to the right of the numerical axis until the second gradient is greater than zero, and the final temperature deviation coefficient is determined based on the initial temperature deviation coefficient and the value of the right shift; When the first gradient is less than zero and the second gradient is greater than zero, the initial temperature deviation coefficient is moved to the left of the numerical axis until the first gradient is greater than zero, and the final temperature deviation coefficient is determined according to the initial temperature deviation coefficient and the left-shifted value; When the first gradient is greater than zero and the second gradient is greater than zero, and when the absolute value of the first gradient is less than the absolute value of the second gradient, update After the first preset random number, the initial temperature deviation coefficient is moved to the left of the number axis until the second gradient is less than zero, and the final temperature deviation coefficient is determined according to the initial temperature deviation coefficient and the left-shifted value; and When the first gradient is greater than zero and the second gradient is greater than zero, and when the absolute value of the first gradient is greater than the absolute value of the second gradient, the initial temperature deviation coefficient is moved to the right of the number axis after updating the first preset random number until the second gradient is less than zero, and the final temperature deviation coefficient is determined based on the initial temperature deviation coefficient and the shifted value.

7. The method according to claim 1, wherein: The reference signal is an impedance signal when the object to be measured is in a healthy state.

8. The method according to claim 1, wherein: The calculation formula of the mean square error value is as follows: Where S i,ref represents the reference impedance signal of the ith monitoring point, S i,x It represents the impedance signal collected at the i-th monitoring point when the damage degree is x, and x represents different damage degrees.

9. The method according to claim 4, wherein: The calculation formula of the average value of the second impedance signal is as follows: Among them, S i T represents the impedance signal at the i-th frequency point after temperature changes, It represents the average value of the impedance signal after temperature changes, and m is the number of frequency points.

10. The method according to claim 4, wherein: The calculation formula of the average value of the reference signal is as follows: Among them, S i 0 It represents the impedance signal at the i-th frequency point at the reference temperature. It represents the average value of the impedance signal at the reference temperature, and m is the number of frequency points.

11. The method according to claim 4, wherein: The calculation formula of the first error value is as follows: The first error value is calculated by the following formula: Among them, m is the number of frequency points, S i T represents the impedance signal at the i-th frequency point after temperature changes, Represents the average value of the impedance signal after temperature changes, S i 0 It represents the impedance signal at the i-th frequency point at the reference temperature. represents the average value of the impedance signal at the reference temperature, σ1 represents the standard deviation of the impedance signal after temperature change, σ0 represents the standard deviation of the impedance signal at the reference temperature, CC(S T ,S 0 ) is the first error value.

12. The method according to claim 6, wherein: The impedance change value is calculated by the following formula: is the first average value, It represents the average value of the impedance signal after the temperature changes, and ΔS is the impedance change value.

13. The method according to claim 6, wherein: The vertical compensation impedance signal is calculated by the following formula: Among them, S 0 is the reference signal, is the first average value, TR is the temperature deviation coefficient, S T is the horizontal compensation signal, and ΔS is the impedance change value.

14. The method according to claim 12, wherein: The initial temperature deviation coefficient is determined according to the amplitude deviation between the horizontal compensation impedance signal and the reference signal, and the initial temperature deviation coefficient is calculated by the following formula: Among them, S TR is the amplitude deviation rate signal.

15. An automatic temperature compensation device, applied to a computer device, wherein: The computer device comprises: a memory and a processor, the memory and the processor are communicatively connected to each other, the memory stores computer instructions, wherein the apparatus comprises: An acquisition module, used to acquire an impedance signal set collected at at least one position of the object to be measured; a first error determination module, configured to determine n error values ​​corresponding to the first impedance signal according to a first impedance signal, n preset offsets, and a pre-acquired reference signal, wherein the first impedance signal is any one of the impedance signal sets collected at the at least one position; A second error determination module, used to determine a final error value according to the n error values ​​and a preset standard; A first compensation signal determination module, configured to determine a horizontal compensation impedance signal according to the offset corresponding to the final error value and the first impedance signal; and a second compensation signal determination module, configured to determine a vertical compensation impedance signal according to the reference signal, the horizontal compensation impedance signal and a temperature deviation coefficient, wherein the temperature deviation coefficient is calculated according to the reference signal and the first impedance signal; The device is also used for: Calculating a mean square error value between at least one vertical compensation impedance signal and the reference signal; When the mean square error value of the vertical compensation impedance signal does not meet the preset condition, determining the position of the corresponding numerical compensation signal as the damage position; Continuously monitoring the impedance signal at the damage location; and The damaged position is continuously monitored according to the impedance signal of the damaged position.

16. The device according to claim 15, wherein: The first impedance signal and the reference signal both include m frequency points, and the first error determination module specifically includes: an offset unit, configured to determine a second impedance signal according to the first impedance signal and a first offset, wherein the first offset is any one of the preset n offsets; a first statistical unit, configured to determine a first statistical parameter of the second impedance signal according to each frequency point in the second impedance signal; a second statistical unit, configured to determine a second statistical parameter of the reference signal according to each frequency point in the reference signal; and An error unit is used to determine a first error value according to the i-th frequency point impedance signal corresponding to the second impedance signal, the i-th frequency point impedance signal corresponding to the reference signal, the first statistical parameter and the second statistical parameter.

17. The device according to claim 16, wherein: The first statistical parameter includes a first mean value and a first standard deviation, and the second statistical parameter includes a second mean value and a second standard deviation.

18. The device according to claim 15, wherein: The second compensation signal determination module specifically includes: an impedance change determining unit, configured to determine an impedance change value according to the first average value and the second average value; A vertical compensation unit, configured to determine the vertical compensation impedance signal according to the reference signal, the first average value, the horizontal compensation impedance signal, the impedance change value and the temperature deviation coefficient; The temperature deviation coefficient in the vertical compensation unit is determined according to the following steps: Determining an initial temperature deviation coefficient according to the reference signal, the horizontal compensation impedance signal, and the number of frequency points; and The initial temperature deviation coefficient is optimized to determine the final temperature deviation coefficient.

19. The device according to claim 18, wherein: The second compensation signal determination module optimizes the initial temperature deviation coefficient to determine the final temperature deviation coefficient, specifically including: a random number determination subunit, configured to determine a first temperature deviation coefficient and a second temperature deviation coefficient according to the initial temperature deviation coefficient, a first preset random number, and a second preset random number, wherein the first temperature deviation coefficient is smaller than the initial temperature deviation coefficient and smaller than the second temperature deviation coefficient, and the first preset random number is smaller than the second preset random number; an error determination subunit, configured to respectively determine a first relative error value corresponding to the initial temperature deviation coefficient, a second relative error value corresponding to the first temperature deviation coefficient, and a third relative error value corresponding to the second temperature deviation coefficient; a first gradient determining subunit, configured to determine a first gradient value according to the first relative error value, the second relative error value, and the first preset random number; a second gradient determining subunit, configured to determine a second gradient value according to the second relative error value, the third relative error value, and the second preset random number; and A coefficient determination unit is used to perform iterative optimization according to the first gradient value and the second gradient value to determine a final temperature deviation coefficient.

20. A computer-readable storage medium, wherein: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the automated temperature compensation method according to any one of claims 1 to 14.

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