CN104181237B - Structural member flaw detection monitoring temperature compensating method and system thereof - Google Patents

Abstract

The invention discloses a temperature compensation method and system for flaw detection monitoring of structural parts, relates to the technical field of structural health monitoring, and is designed to solve problems such as troublesome acquisition of reference signals in the existing temperature compensation method for flaw detection monitoring of structural parts. The temperature compensation method for flaw detection monitoring of structural parts provided by the present invention determines the compensation parameter value by comparing the reference signal at any temperature with the characteristic points of the current signal at any temperature, and then moves and coordinates the reference signal wave according to the compensation parameter value deformation, so as to realize the temperature compensation of the current signal. The present invention can eliminate the influence of temperature changes on the signal without collecting a large number of reference signals at various temperatures, save a lot of time and operating costs for the health monitoring of the structure, has strong practicability, and has wide applications prospect.

Description

A temperature compensation method and system for flaw detection monitoring of structural parts

technical field

The invention relates to the technical field of structural health monitoring, in particular to a temperature compensation method and system for flaw detection monitoring of structural parts.

Background technique

Under the long-term effects of cyclic loads and various extreme environments, the key structures of aircraft and other mechanical equipment may be damaged, such as corrosion and deformation of metal structures, delamination and debonding of composite material structures, etc. If these damages cannot be discovered and repaired in time, they will cause great potential safety hazards. Therefore, these damages need to be identified. The identification method is to obtain the current signal by monitoring the monitored part through the sensor and compare the current signal with the reference signal to obtain the location of the damage. , size etc.

Since the change of temperature will affect the material properties of the structure, the properties of the sensor, and the properties of the adhesive layer bonding the sensor, etc., when the ambient temperature of the structure changes, the signal wave propagation properties, such as amplitude and wave speed, etc., There will also be changes. When performing quantitative identification of damage, it is often necessary to use the baseline method for signal analysis. At this time, small changes in wave amplitude and wave velocity will often cause large signal differences, which will seriously affect the results of damage identification. Therefore, temperature compensation is required.

At present, there are many methods of temperature compensation. Basically, the working temperature of the structure is divided into dozens of small temperature intervals first, and the current signal at a certain temperature is compared with the reference signal at the corresponding temperature. The advantage of this type of method is that it is very reliable for any type of structure, but the disadvantage is that it is often troublesome to collect reference signals in various temperature ranges. For example, for a large aircraft structure, to reduce its structural temperature to minus 50 degrees or rise to minus 60 degrees requires a large, high-precision temperature control workshop, which is difficult to achieve.

In view of the above problems, there is an urgent need for a temperature compensation method and system that can better eliminate the influence of temperature without collecting reference signals in various temperature ranges.

Contents of the invention

An object of the present invention is to propose a temperature compensation method for flaw detection monitoring of structural parts, which can save a lot of time and operating costs for structural health monitoring.

Another object of the present invention is to propose a temperature compensation system for flaw detection monitoring of structural parts, which can save a lot of time and operating costs for structural health monitoring.

For reaching this purpose, on the one hand, the present invention adopts following technical scheme:

A temperature compensation method for flaw detection monitoring of structural parts, the method at least includes the following steps:

Step A, providing a waveform diagram of the reference signal at the first temperature;

Step B, obtaining the current signal waveform at the second temperature;

Step C, taking the current signal feature points of the current signal wave at the second temperature, and taking the reference signal feature points of the reference signal waveform at the first temperature, the current signal feature points corresponding to the reference signal feature points respectively, Comparing the current signal feature point with the reference signal feature point to obtain the compensation parameter value;

Step D, moving and deforming the reference signal wave at the first temperature according to the compensation parameter value, to obtain the reference signal waveform at the second temperature.

Further, both the reference signal waveform diagram and the current signal waveform diagram have time as the horizontal axis and amplitude as the vertical axis, and the compensation parameters at least include time compensation parameters and amplitude compensation parameters.

Preferably, the signal characteristic point is a peak and/or a trough of the signal wave and/or an intersection point of the signal wave and the horizontal axis.

Preferably, the time compensation parameter is a characteristic point time difference between the reference signal wave at the first temperature and the reference signal wave at the second temperature.

Preferably, the reference signal includes at least a first reference signal and a second reference signal, and the method for obtaining the reference signal is:

providing a first sensor, a second sensor and a monitored item;

The first reference signal is a signal excited by the first sensor and transmitted directly to the second sensor;

The second reference signal is a signal excited by the first sensor, reflected by the monitored element, and then transmitted to the second sensor.

Preferably, the current signal includes at least a first current signal and a second current signal, and the method for obtaining the current signal is:

providing a first sensor, a second sensor and a monitored item;

The first current signal is a signal excited by the first sensor and transmitted directly to the second sensor;

The second current signal is formed by superimposing two parts of the signal, one part is the signal excited by the first sensor, reflected by the monitored part, and then transmitted to the second sensor, and the other part is the signal excited by the first sensor, passed by the monitored part The signal reflected by the damaged part is then transmitted to the second sensor.

Preferably, the method is specifically:

Take the characteristic point peak J1 (J1t, J1a) and valley J2 (J2t, J2a) of the excitation signal,

Take the characteristic point peak B1 (B1t, B1a) and valley B2 (B2t, B2a) of the first reference signal at the first temperature, and the characteristic point peak B3 (B3t, B3a) and valley B4 (B4t, B4a) of the second reference signal ),

Take the peak Ac1 (Ac1t, Ac1a) and valley Ac2 (Ac2t, Ac2a) of the first current signal at the second temperature,

When the damaged part of the monitored part is not on the path of the first sensor and the second sensor, the first reference signal at the second temperature is the same as the first current signal at the second temperature, and the second reference signal at the first temperature is The signal wave is shifted to the right by the time compensation parameter Δt2 and its waveform is amplified by the ratio of the amplitude compensation parameter R3 to obtain the second reference signal at the second temperature,

$\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; \&CenterDot;</span>\mathrm{<span\; class="notranslate">\; \&Delta;TB</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; \&Delta;TB</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; ,</span>$

Wherein, Δt1 is the time difference between the first reference signal at the second temperature and the first reference signal at the first temperature, $\mathrm{\&Delta;t}1=\frac{\mathrm{Ac}1t-B1t+\mathrm{Ac}2t-B2t}{2},$

ΔTB1 is the time difference between the first reference signal and the excitation signal at the first temperature,

$\mathrm{<span\; class="notranslate">\; \&Delta;TB</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; B</span>}\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; J</span>}\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; B</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; J</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ,</span>$

ΔTB2 is the time difference between the second reference signal and the excitation signal under the first temperature condition,

$\mathrm{<span\; class="notranslate">\; \&Delta;TB</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; B</span>}\mathrm{<span\; class="notranslate">\; 3</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; J</span>}\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; B</span>}\mathrm{<span\; class="notranslate">\; 4</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; J</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ;</span>$

$\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; \&CenterDot;</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&Delta;TB</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&Delta;TB</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ,</span>$

in, $R1=\frac{\mathrm{Ac}1a}{B1a}.$

Preferably, f(ΔTB1)=ΔTB1, f(ΔTB2)=ΔTB2.

On the other hand, the present invention adopts the following technical solutions:

A temperature compensation system for flaw detection monitoring of structural parts, used to implement the above temperature compensation method for flaw detection monitoring of structural parts, said temperature compensation system includes a signal excitation device, a detection device, a signal acquisition device, a wave signal temperature compensation device and a control panel, wherein , the signal excitation device is used to provide an excitation signal; the detection device includes a wave signal sensor for providing the current signal wave and a temperature sensor for detecting the second temperature; the signal acquisition device is used for collecting the current signal wave and The second temperature signal is transmitted to the wave signal temperature compensation system; the wave signal temperature compensation device is pre-stored with a reference signal waveform diagram at the first temperature, which is used to temperature the current signal wave at the second temperature. Compensation; the control panel includes a display screen for displaying temperature compensation results and a control interface for controlling the temperature compensation process.

Preferably, the waveform diagram of the reference wave signal at the first temperature pre-stored in the wave signal temperature compensation device is pre-detected by the detection device, and then transmitted to the wave signal temperature after being collected by the signal acquisition device. compensation device.

The beneficial effects of the present invention are: the temperature compensation method and system for structural component flaw detection monitoring provided by the present invention can determine the compensation parameter value by comparing the reference signal at any temperature with the characteristic points of the current signal at any temperature, and then according to the The compensation parameter value moves and deforms the reference signal wave, so as to realize the temperature compensation of the reference signal. It does not need to collect a large number of reference signals at various temperatures to eliminate the influence of temperature changes on the signal. Health monitoring saves a lot of time and operating costs, has strong practicability, and has broad application prospects.

Description of drawings

Fig. 1 is a schematic diagram of flaw detection monitoring of a monitored part provided by a specific embodiment of the present invention;

Fig. 2 is a reference signal waveform diagram under the first temperature and the second temperature provided by the specific embodiment of the present invention;

Fig. 3 is a current signal waveform diagram at a second temperature provided by a specific embodiment of the present invention;

Fig. 4 is a structural schematic diagram of a temperature compensation system for flaw detection monitoring of structural parts provided by the present invention.

In the figure, 1, the first sensor; 2, the second sensor; 3, the reinforcing rib; 4, the damaged part.

detailed description

The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and through specific implementation methods.

The temperature compensation method for flaw detection monitoring of structural parts of the present invention at least includes the following steps:

Step A, providing a waveform diagram of the reference signal at the first temperature;

Step B, obtaining the current signal waveform at the second temperature;

Step C, taking the current signal feature points of the current signal wave at the second temperature, and taking the reference signal feature points of the reference signal waveform at the first temperature, the current signal feature points corresponding to the reference signal feature points respectively, Comparing the current signal feature point with the reference signal feature point to obtain the compensation parameter value;

Step D, moving and deforming the reference signal wave at the first temperature according to the compensation parameter value, to obtain the reference signal waveform at the second temperature.

Wherein, since both the reference signal waveform diagram and the current signal waveform diagram take time as the horizontal axis and amplitude as the vertical axis, the compensation parameters are preferably time compensation parameters and amplitude compensation parameters; the signal feature points are not specifically limited, and can be The peaks and/or troughs and/or intersection points of the signal wave and the horizontal axis can be easily compared.

Since this method does not need to collect a large number of reference signals at various temperatures, it can well eliminate the influence of temperature changes on the signal, so it saves a lot of time and operating costs for the health monitoring of structures, and has strong practicability and broad application potential. application prospects.

In view of the above method, the present invention also proposes a temperature compensation system for flaw detection monitoring of structural parts, which is used to realize the above temperature compensation method for flaw detection monitoring of structural parts. As shown in Figure 4, the temperature compensation system includes a signal excitation device, a detection device, a signal acquisition device, a wave signal temperature compensation device and a control panel. Wherein, the signal excitation device is used to provide the excitation signal; the detection device includes a wave signal sensor for providing the current signal wave and a temperature sensor for detecting the second temperature; the signal acquisition device is used for collecting the current signal wave and the second temperature signal and It is transmitted to the wave signal temperature compensation system; the wave signal temperature compensation device is pre-stored with the reference signal waveform diagram at the first temperature, which is used for temperature compensation of the current signal wave at the second temperature; the control panel includes a display for displaying the temperature compensation result Display and control interface for controlling the temperature compensation process.

Among them, the reference signal waveform at the first temperature pre-existing in the wave signal temperature compensation device can be detected by the detection device in advance, and then transmitted to the wave signal temperature compensation device after being collected by the signal acquisition device, and can also be measured on other equipment After that, it is stored in the wave signal temperature compensation device.

The temperature compensation method of the present invention will be described in detail below by taking a structure containing reinforcing ribs as an example.

As shown in FIG. 1 , a first sensor 1 and a second sensor 2 are provided for health monitoring.

The reference signal includes at least a first reference signal and a second reference signal. The first reference signal is a signal excited by the first sensor 1 and directly transmitted to the second sensor 2 ; the second reference signal is a signal excited by the first sensor 1 , reflected by the rib 3 , and then transmitted to the second sensor 2 .

The current signal includes at least a first current signal and a second current signal. The first current signal is a signal excited by the first sensor 1 and directly transmitted to the second sensor 2; the second current signal is formed by superimposing two parts of the signal, one part is excited by the first sensor 1, reflected by the rib 3, and then Another part of the signal transmitted to the second sensor 2 is the signal excited by the first sensor 1 , reflected by the damaged part 4 , and then transmitted to the second sensor 2 .

Figure 2 and Figure 3 are waveform diagrams of the reference signal and the current signal. As shown in Figure 2, the wave group in the left ellipse is the excitation signal wave; in the wave group in the middle ellipse, the dotted line wave is the first reference signal wave at the first temperature, and the solid line wave is the wave at the second temperature. The first reference signal wave of ; in the wave group in the ellipse on the right, the dotted line wave is the second reference signal wave at the first temperature, and the solid line wave is the second reference signal wave at the second temperature. As shown in FIG. 3 , the left side is the excitation signal wave, the wave group in the middle ellipse is the first current signal wave at the second temperature, and the wave group in the right ellipse is the second current signal wave at the second temperature. Among them, the reference signal waveform at the first temperature and the current reference signal waveform at the second temperature are known, our purpose is to obtain the reference signal wave at the second temperature, so as to compare the reference signal wave at the second temperature with The current signal wave at the second temperature is compared to obtain the condition of the damaged part.

Firstly, feature points need to be taken, and in this embodiment, the peaks and troughs are taken. Take the characteristic point peak J1 (J1t, J1a) and valley J2 (J2t, J2a) of the excitation signal respectively, and take the characteristic point peak B1 (B1t, B1a) and valley B2 (B2t, B2a) of the first reference signal at the first temperature ), the characteristic point peak B3 (B3t, B3a) and valley B4 (B4t, B4a) of the second reference signal, and the characteristic point Ac1 (Ac1t, Ac1a) and valley Ac2 (Ac2t) of the first current signal at the second temperature , Ac2a). Correspondingly, the characteristic point peak A1 (A1t, A1a) and valley A2 (A2t, A2a) of the first reference signal at the second temperature, the characteristic point peak A3 (A3t, A3a) of the second reference signal at the second temperature ) and trough A4 (A4t, A4a).

Time compensation: when the damaged part is not on the path of the first sensor 1 and the second sensor 2, since the acquisition conditions and acquisition methods are the same, the first reference signal at the second temperature and the first current signal at the second temperature are basically The same, so it is only necessary to obtain the second reference signal at the second temperature, and A1t=Ac1t, A1a=Ac1a; A2t=Ac2t, A2a=Ac2a.

For the same wave group, that is, the wave group in the same ellipse in the figure, assuming that the time differences of the characteristic points caused by temperature are the same, the time difference between the first reference signal at the second temperature and the first reference signal at the first temperature

$\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; A</span>}\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; B</span>}\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; A</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; B</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; Ac</span>}\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; B</span>}\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; Ac</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; B</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ,</span>$

The time difference between the second reference signal at the second temperature and the second reference signal at the first temperature

$\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; A</span>}\mathrm{<span\; class="notranslate">\; 3</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; B</span>}\mathrm{<span\; class="notranslate">\; 3</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; A</span>}\mathrm{<span\; class="notranslate">\; 4</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; B</span>}\mathrm{<span\; class="notranslate">\; 4</span>}\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ,</span>$

The time difference between the first reference signal and the excitation signal at the first temperature

$\mathrm{<span\; class="notranslate">\; \&Delta;TB</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; B</span>}\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; J</span>}\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; B</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; J</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ,</span>$

The time difference between the second reference signal and the excitation signal under the first temperature condition

$\mathrm{<span\; class="notranslate">\; \&Delta;TB</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; B</span>}\mathrm{<span\; class="notranslate">\; 3</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; J</span>}\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; B</span>}\mathrm{<span\; class="notranslate">\; 4</span>}\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; J</span>}\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; t</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ,</span>$

Assuming that the wave propagation in the monitoring area is affected by the same degree of temperature, then,

$\frac{\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Delta;t</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&Delta;TB</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; \&Delta;TB</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; ,</span>$

Therefore, the time compensation parameter can be obtained Δt1, ΔTB2, and ΔTB1 can all be obtained by calculation. Shifting the second reference signal wave at the first temperature to the right by the time compensation parameter Δt2 can eliminate the change of the time difference caused by the temperature.

When calculating the time difference, it is not necessary to calculate the average value, and calculate each corresponding peak or trough separately, that is, determine the time difference between A3 and B3 with the time difference between A1 and B1, and determine the time difference between A4 and B4 with the time difference between A2 and B2. Appropriate selection can be made according to the waveform during application.

Amplitude compensation: the amplitude ratio of the first reference signal at the second temperature to the first reference signal at the first temperature can be expressed as $R1=\frac{A1a}{B1a}=\frac{\mathrm{Ac}1a}{B1a},$

The amplitude ratio of the second reference signal at the second temperature to the second reference signal at the first temperature can be expressed as $R3=\frac{A3a}{B3a},$

Let R1, R3 and ΔTB1, ΔTB2 satisfy the relationship

Amplitude Compensation Parameters Available

The second reference signal at the second temperature can be obtained by amplifying the waveform of the translated wave by the ratio of the amplitude compensation parameter R3.

The f(x) function in the above formula can be determined through experiments, theoretical analysis or numerical simulation. For the sake of simplicity, f(x)=x when the precision is not very high.

It should be pointed out that this compensation method is only applicable when the damaged part is not on the path of the sensor, and other methods need to be used for processing when the damaged part is on the path of the sensor.

The above describes the technical principles of the present invention in conjunction with specific embodiments. These descriptions are only for explaining the principles of the present invention, and cannot be construed as limiting the protection scope of the present invention in any way. Based on the explanations herein, those skilled in the art can think of other specific implementation modes of the present invention without creative work, and these modes will all fall within the protection scope of the present invention.

Claims (7)

1. A temperature compensation method for flaw detection monitoring of structural parts, characterized in that said method at least comprises the following steps: Step A, providing a waveform diagram of the reference signal at the first temperature; Step B, obtaining the current signal waveform at the second temperature; Step C, taking the current signal feature points of the current signal wave at the second temperature, and taking the reference signal feature points of the reference signal waveform at the first temperature, the current signal feature points corresponding to the reference signal feature points respectively, Comparing the current signal feature point with the reference signal feature point to obtain the compensation parameter value; Step D, moving and deforming the reference signal wave at the first temperature according to the compensation parameter value, to obtain the reference signal waveform at the second temperature; Both the reference signal waveform diagram and the current signal waveform diagram have time as the horizontal axis and amplitude as the vertical axis, and the compensation parameters at least include time compensation parameters and amplitude compensation parameters; The time compensation parameter is the characteristic point time difference between the reference signal wave at the first temperature and the reference signal wave at the second temperature; The reference signal includes at least a first reference signal and a second reference signal, and the method for obtaining the reference signal is: providing a first sensor (1), a second sensor (2) and a monitored piece; The first reference signal is a signal excited by the first sensor (1) and directly transmitted to the second sensor (2); The second reference signal is a signal excited by the first sensor (1), reflected by the monitored part, and then transmitted to the second sensor (2). 2 . The temperature compensation method for flaw detection monitoring of structural parts according to claim 1 , wherein the signal characteristic point is the peak and/or trough of the signal wave and/or the intersection point of the signal wave and the horizontal axis. 3 . 3. A temperature compensation method for flaw detection monitoring of structural parts according to claim 1, characterized in that, The current signal at least includes a first current signal and a second current signal, and the method for obtaining the current signal is: providing a first sensor (1), a second sensor (2) and a monitored piece; The first current signal is a signal excited by the first sensor (1) and transmitted directly to the second sensor (2); The second current signal is superimposed by two parts of the signal, one part is the signal excited by the first sensor (1), reflected by the monitored part, and then transmitted to the second sensor (2), and the other part is the signal generated by the first sensor (1) The signal that is excited, reflected by the damaged part (4) of the monitored part, and then transmitted to the second sensor (2). 4. A temperature compensation method for flaw detection monitoring of structural parts according to claim 3, characterized in that, the method is specifically: Take the characteristic point peak J1(J1t, J1a) and valley J2(J2t, J2a) of the excitation signal, Take the characteristic point peak B1 (B1t, B1a) and valley B2 (B2t, B2a) of the first reference signal at the first temperature, and the characteristic point peak B3 (B3t, B3a) and valley B4 (B4t, B4a) of the second reference signal ), Take the characteristic point peak Ac1 (Ac1t, Ac1a) and valley Ac2 (Ac2t, Ac2a) of the first current signal at the second temperature, When the damaged part (4) of the monitored part is not on the path of the first sensor (1) and the second sensor (2), the first reference signal at the second temperature is the same as the first current signal at the second temperature, The second reference signal wave at the first temperature is shifted to the right by the time compensation parameter Δt2 and its waveform is amplified by the ratio of the amplitude compensation parameter R3 to obtain the second reference signal at the second temperature, $\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; T</span>}\mathrm{<span\; class="notranslate">\; B</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; T</span>}\mathrm{<span\; class="notranslate">\; B</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; ,</span>$ Wherein, Δt1 is the time difference between the first reference signal at the second temperature and the first reference signal at the first temperature, ΔTB1 is the time difference between the first reference signal and the excitation signal at the first temperature, ΔTB2 is the time difference between the second reference signal and the excitation signal under the first temperature condition, $\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; R</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; \&Center\; Dot;</span>\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; T</span>}\mathrm{<span\; class="notranslate">\; B</span>}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; f</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; T</span>}\mathrm{<span\; class="notranslate">\; B</span>}\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}<span\; class="notranslate">\; ,</span>$ in, 5. A temperature compensation method for flaw detection monitoring of structural parts according to claim 4, characterized in that: f(ΔTB1)=ΔTB1, f(ΔTB2)=ΔTB2. 6. A temperature compensation system for flaw detection monitoring of structural parts, used to implement the temperature compensation method for flaw detection monitoring of structural parts according to any one of claims 1 to 5, characterized in that: the temperature compensation system includes a signal excitation device, a detection device, signal acquisition device, wave signal temperature compensation device and control panel, wherein, a signal excitation device for providing an excitation signal; detection means comprising a wave signal sensor for providing said current signal wave and a temperature sensor for detecting said second temperature; a signal acquisition device, configured to acquire the current signal wave and the second temperature signal and transmit them to the wave signal temperature compensation system; A wave signal temperature compensation device, which pre-stores a reference signal waveform diagram at the first temperature for temperature compensation of the current signal wave at the second temperature; A control panel including a display screen for displaying temperature compensation results and a control interface for controlling the temperature compensation process. 7. A temperature compensation system for flaw detection monitoring of structural parts according to claim 6, characterized in that: the waveform diagram of the reference wave signal at the first temperature pre-stored in the wave signal temperature compensation device is prepared in advance by the The detection device detects, and then transmits to the wave signal temperature compensation device after being collected by the signal collection device.