A microwave detection method and system

Abstract

This invention discloses a microwave inspection method and system, relating to the field of nondestructive testing (NDT) technology. The method includes: moving a detection unit along a predetermined direction to scan the object under test, obtaining the envelopes of microwave signals to be processed at different locations on the object; the detection unit includes one, two, or four sensors; the microwave signals to be processed are interference signals or microwave signals reflected by the object under test; the interference signal is generated by the interference between the microwave signal emitted by the microwave signal transmitter and the microwave signal reflected by the object; and the location of damage on the object is determined based on the envelopes of the microwave signals to be processed at each location on the object. This invention can improve the accuracy of NDT results and achieve damage detection without macroscopic defects, such as cold welding damage in hot-melt joints.

Description

Technical Field

[0001] This invention relates to the field of nondestructive testing technology, and in particular to a microwave testing method and system. Background Technology

[0002] Glass fiber reinforced composite materials and non-metallic materials such as polyethylene are widely used in aerospace, marine, construction, and medical fields. As the application scope of non-metallic materials expands and safety requirements become increasingly stringent, the detection of damage and performance degradation in these applications is receiving increasing attention.

[0003] During this period, numerous scholars both domestically and internationally conducted in-depth research on non-destructive testing of non-metals, employing techniques including ultrasonic testing, microwave testing, X-ray testing, and infrared thermography. Among these, ultrasonic and microwave testing technologies offer higher efficiency and wider application. Microwave testing, in particular, has gained widespread use due to its portable equipment, simple operation, low maintenance costs, real-time and rapid detection capabilities, and its non-contact nature, eliminating the need for coupling agents. However, current microwave testing based on radiation intensity suffers from limitations. Uneven surfaces of the tested object and vibrations in the scanning mechanism cause changes in the distance between the tested object and the microwave signal transmitter, affecting measurement accuracy and resulting in low precision. This makes it impossible to detect damage without macroscopic defects, such as cold weld damage in hot-melt joints. Summary of the Invention

[0004] The purpose of this invention is to provide a microwave testing method and system that can improve the accuracy of non-destructive testing results and realize damage detection without macroscopic defects, such as cold welding damage of hot melt joints.

[0005] To achieve the above objectives, the present invention provides the following solution:

[0006] A microwave detection method, comprising:

[0007] The detection unit moves along a predetermined direction to scan the object being detected, obtaining the envelopes of the microwave signals to be processed at different positions on the object. The detection unit includes one sensor, two sensors with a spatial phase difference of 90 degrees, or four sensors. The four sensors include a first sensor, a second sensor, a third sensor, and a fourth sensor. The first sensor and the third sensor have a spatial phase difference of 90 degrees. The microwave signal to be processed is an interference signal or a microwave signal emitted by a microwave signal transmitter reflecting from the object being detected. The interference signal is generated by the interference between the microwave signal emitted by the microwave signal transmitter and the microwave signal emitted by the microwave signal transmitter reflecting from the object being detected.

[0008] The location of damage to the object can be determined by the envelope of the microwave signal to be processed at each location of the object being tested.

[0009] Optionally, when the detection unit includes a sensor, and the microwave signal to be processed is an interference signal or a microwave signal emitted by a microwave signal transmitting device reflected by the object being detected, obtaining the location of damage to the object being detected based on the envelope of the microwave signal to be processed at each location of the object being detected specifically includes:

[0010] For any location of the object being tested, the damage parameters at that location are obtained based on the envelope of the microwave signal to be processed at that location; the damage parameters are standing wave ratio, microwave reflection coefficient, or return loss.

[0011] The location of damage to the tested object is obtained based on the damage parameters at various locations of the tested object.

[0012] Optionally, when the detection unit includes four sensors and the microwave signal to be processed is an interference signal, obtaining the location of damage to the object based on the envelope of the microwave signal to be processed at each location of the object specifically includes:

[0013] For any position of the object being detected, the sum of the squares of the first difference at that position and the sum of the squares of the second difference at that position are calculated to obtain the parameter value at that position. The first difference at that position is the difference between the square of the envelope of the microwave signal to be processed at that position acquired by the first sensor and the square of the envelope of the microwave signal to be processed at that position acquired by the second sensor. The second difference at that position is the difference between the square of the envelope of the microwave signal to be processed at that position acquired by the third sensor and the square of the envelope of the microwave signal to be processed at that position acquired by the fourth sensor.

[0014] The location of damage to the tested object can be determined based on the parameter values ​​at each location.

[0015] Optionally, when the detection unit includes two sensors with a spatial phase difference of 90 degrees and the microwave signal to be processed is an interference signal or a microwave signal emitted by a microwave signal transmitting device reflected by the object being detected, the step of obtaining the location of damage to the object being detected based on the envelope of the microwave signal to be processed at each location of the object being detected specifically includes:

[0016] For any position of the object being detected, a “z1-z3” graph is plotted with the square of the envelope of the microwave signal to be processed at the position of the object being detected collected by the first sensor as the horizontal axis and the square of the envelope of the microwave signal to be processed at the position of the object being detected collected by the second sensor as the vertical axis.

[0017] The damage parameters at the location of the object under test are obtained from the "z1-z3" diagram at the location of the object under test.

[0018] The location of damage to the tested object is obtained based on the damage parameters at various locations of the tested object.

[0019] Optionally, when the detection unit includes two sensors with a spatial phase difference of 90 degrees, and the microwave signal to be processed is a microwave signal emitted by a microwave signal transmitting device reflected by the object being detected; the step of obtaining the location of damage to the object being detected based on the envelope of the microwave signal to be processed at each location of the object being detected specifically includes:

[0020] For any position of the object being detected, the fourth power of the envelope of the microwave signal to be processed at the position of the object being detected, collected by the first sensor, and the fourth power of the envelope of the microwave signal to be processed at the position of the object being detected, collected by the second sensor, are used to obtain the parameter value at the position of the object being detected.

[0021] The location of damage to the tested object can be determined based on the parameter values ​​at each location.

[0022] A microwave detection system, comprising:

[0023] An envelope acquisition module is used to move a detection unit along a set direction to scan the object being detected, obtaining the envelope of the microwave signal to be processed at different positions of the object being detected. The detection unit includes one sensor, two sensors with a spatial phase difference of 90 degrees, or four sensors. The four sensors include a first sensor, a second sensor, a third sensor, and a fourth sensor. The first sensor and the third sensor have a spatial phase difference of 90 degrees. The microwave signal to be processed is an interference signal or a microwave signal emitted by a microwave signal transmitting device reflected by the object being detected. The interference signal is a signal generated by the interference between the microwave signal emitted by the microwave signal transmitting device and the microwave signal emitted by the microwave signal transmitting device reflected by the object being detected.

[0024] The damage location determination module is used to determine the location of damage to the object being tested based on the envelope of the microwave signal to be processed at each location of the object being tested.

[0025] Optionally, when the detection unit includes a sensor, and the microwave signal to be processed is an interference signal or a microwave signal emitted by a microwave signal transmitting device reflected by the object being detected, the damage location determination module specifically includes:

[0026] The first damage parameter determination unit is used to obtain the damage parameter at any location of the object being tested based on the envelope of the microwave signal to be processed at that location; the damage parameter is the standing wave ratio, microwave reflection coefficient, or return loss.

[0027] The first damage location determination unit is used to determine the location of damage to the object being tested based on the damage parameters at each location of the object being tested.

[0028] Optionally, when the detection unit includes four sensors and the microwave signal to be processed is an interference signal, the damage location determination module specifically includes:

[0029] The first parameter value calculation unit is used to calculate, for any position of the detected object, the sum of the squares of the first difference at the position of the detected object and the sum of the squares of the second difference at the position of the detected object to obtain the parameter value at the position of the detected object; the first difference at the position of the detected object is the difference between the square of the envelope of the microwave signal to be processed at the position of the detected object collected by the first sensor and the square of the envelope of the microwave signal to be processed at the position of the detected object collected by the second sensor; the second difference at the position of the detected object is the difference between the square of the envelope of the microwave signal to be processed at the position of the detected object collected by the third sensor and the square of the envelope of the microwave signal to be processed at the position of the detected object collected by the fourth sensor.

[0030] The second damage location determination unit is used to determine the location of damage to the object being tested based on the parameter values ​​at each location of the object being tested.

[0031] Optionally, when the detection unit includes two sensors with a spatial phase difference of 90 degrees and the microwave signal to be processed is an interference signal or a microwave signal emitted by a microwave signal transmitting device reflected by the object being detected, the damage location determination module specifically includes:

[0032] The plotting unit is used to plot a "z1-z3" graph of any position of the object being detected, with the square of the envelope of the microwave signal to be processed at the position of the object being detected collected by the first sensor as the horizontal axis and the square of the envelope of the microwave signal to be processed at the position of the object being detected collected by the second sensor as the vertical axis.

[0033] The second damage parameter determination unit is used to obtain the damage parameters at the location of the object being tested based on the "z1-z3" diagram at the location of the object being tested.

[0034] The third damage location determination unit is used to determine the location of damage to the object being tested based on the damage parameters at each location of the object being tested.

[0035] Optionally, when the detection unit includes two sensors with a spatial phase difference of 90 degrees, and the microwave signal to be processed is a microwave signal emitted by a microwave signal transmitting device reflected by the object being detected; the damage location determination module specifically includes:

[0036] The second parameter value calculation unit is used to calculate the fourth power of the envelope of the microwave signal to be processed at the location of the detected object acquired by the first sensor and the fourth power of the envelope of the microwave signal to be processed at the location of the detected object acquired by the second sensor for any location of the detected object, so as to obtain the parameter value at the location of the detected object.

[0037] The fourth damage location determination unit is used to determine the location of damage to the object being tested based on the parameter values ​​at each location of the object being tested.

[0038] According to specific embodiments provided by the present invention, the present invention discloses the following technical effects: The present invention moves the detection unit along a set direction to scan the object under test, and obtains the envelope of the microwave signal to be processed at different positions of the object under test; the detection unit includes one sensor, two sensors with a spatial phase difference of 90 degrees, or four sensors; the microwave signal to be processed is an interference signal or a microwave signal emitted by a microwave signal emitting device reflected by the object under test; the interference signal is a signal generated by the interference between the microwave signal emitted by the microwave signal emitting device and the microwave signal emitted by the microwave signal emitting device reflected by the object under test; the location of damage to the object under test is obtained according to the envelope of the microwave signal to be processed at each position of the object under test; based on spatial coherent distribution of single, dual, and multi-sensor spatial sampling, the accuracy of non-destructive testing results can be improved, and damage detection without macroscopic defects such as cold welding damage of hot melt joints can be realized. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 A flowchart of the microwave detection method provided in the embodiments of the present invention;

[0041] Figure 2 This is a schematic diagram showing the positional relationship between the object being tested and the microwave signal transmitting device. Detailed Implementation

[0042] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0043] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] The impact of damage to the object under test on the reflected wave includes changes in the reflection coefficient and phase. Since the distance between the microwave signal transmitter and the surface of the object under test, as well as phase changes, can all affect the measurement of changes in the reflection coefficient, this invention addresses this issue. Specifically, even slight jitter or minute changes in the surface condition of the object can affect the detection, making it difficult to reflect changes in the object's thickness, density, material, and damage. Therefore, this invention proposes a method for detecting changes in the object's loss, performance, and structure using microwaves. Based on spatially coherent distribution of single, dual, and multi-probe spatial sampling and scanning, this method achieves rapid microwave non-destructive testing under conditions of low system complexity. It can improve the accuracy of non-destructive testing results and enable the detection of damage without macroscopic defects, such as cold welding damage in hot-melt joints.

[0045] Example 1

[0046] like Figure 1 As shown, the microwave detection method provided in this embodiment of the invention includes:

[0047] Step 101: Move the detection unit along the set direction to scan the object being detected, and obtain the envelope of the microwave signal to be processed at different positions of the object being detected; the detection unit includes one sensor, two sensors with a spatial phase difference of 90 degrees, or four sensors; the four sensors include a first sensor, a second sensor, a third sensor, and a fourth sensor; the first sensor and the third sensor have a spatial phase difference of 90 degrees; the microwave signal to be processed is an interference signal or a microwave signal emitted by a microwave signal emitting device reflected by the object being detected; the interference signal is a signal generated by the interference between the microwave signal emitted by the microwave signal emitting device and the microwave signal emitted by the microwave signal emitting device reflected by the object being detected.

[0048] Step 102: Obtain the location of damage to the object based on the envelope of the microwave signal to be processed at each location of the object being tested.

[0049] In practical applications, the direction is set as the direction from the microwave signal transmitting device to the object being detected, or along a plane parallel to the direction from the microwave signal transmitting device to the object being detected.

[0050] In practical applications, when the detection unit includes a sensor, and the microwave signal to be processed is an interference signal or a microwave signal emitted by a microwave signal transmitting device reflected by the object being detected, the step of obtaining the location of damage to the object being detected based on the envelope of the microwave signal to be processed at each location of the object being detected specifically includes:

[0051] For any location of the object being tested, the damage parameters at that location are obtained based on the envelope of the microwave signal to be processed at that location; the damage parameters are standing wave ratio, microwave reflection coefficient, or return loss.

[0052] The location of damage to the tested object is obtained based on the damage parameters at various locations of the tested object.

[0053] In practical applications, when using a single sensor for measurement, there is a situation where, when the complex reflection coefficient is low, ||S0|| 2 (z) The amplitude of the variation component in the signal is low, and even small measurement errors can significantly affect the detection results. Furthermore, scanning along the direction from the microwave signal transmitter to the object being detected is required, resulting in low detection efficiency. Therefore, four sensors are used for measurement. When the detection unit includes four sensors, and the microwave signal to be processed is an interference signal, the location of damage to the object is determined based on the envelope of the microwave signal to be processed at each position of the object. Specifically, this includes:

[0054] For any position of the object being detected, the sum of the squares of the first difference at that position and the sum of the squares of the second difference at that position are calculated to obtain the parameter value at that position. The first difference at that position is the difference between the square of the envelope of the microwave signal to be processed at that position acquired by the first sensor and the square of the envelope of the microwave signal to be processed at that position acquired by the second sensor. The second difference at that position is the difference between the square of the envelope of the microwave signal to be processed at that position acquired by the third sensor and the square of the envelope of the microwave signal to be processed at that position acquired by the fourth sensor.

[0055] The location of damage to the tested object can be determined based on the parameter values ​​at each location.

[0056] In practical applications, using four sensors results in an excessive number of sensors, which can complicate the system and, in extreme cases, interfere with the spatial microwave distribution. Therefore, two sensors are used for measurement. When the detection unit includes two sensors with a spatial phase difference of 90 degrees and the microwave signal to be processed is an interference signal or a microwave signal emitted by a microwave signal transmitting device reflected by the object being detected, the step of obtaining the location of damage to the object being detected based on the envelope of the microwave signal to be processed at each location of the object being detected specifically includes:

[0057] For any location of the object being detected, a "z1-z3" graph is plotted with the square of the envelope of the microwave signal to be processed at the location of the object being detected, collected by the first sensor, as the horizontal axis and the square of the envelope of the microwave signal to be processed at the location of the object being detected, collected by the second sensor, as the vertical axis.

[0058] The damage parameters at the location of the object under test are obtained from the "z1-z3" diagram at the location of the object under test.

[0059] The location of damage to the tested object is obtained based on the damage parameters at various locations of the tested object.

[0060] In practical applications, when using a single sensor, scanning is required along the direction from the microwave signal transmitter to the object being detected, resulting in low detection efficiency. Therefore, two sensors are used. The detection unit includes two sensors with a spatial phase difference of 90 degrees, and the microwave signal to be processed is the microwave signal emitted by the microwave signal transmitter reflected by the object being detected. The step of obtaining the location of damage to the object based on the envelope of the microwave signal to be processed at each position of the object specifically includes:

[0061] For any location of the object being detected, the parameter value at that location is obtained by calculating the fourth power of the envelope of the microwave signal to be processed at that location acquired by the first sensor and the fourth power of the envelope of the microwave signal to be processed at that location acquired by the second sensor.

[0062] The location of damage to the tested object can be determined based on the parameter values ​​at each location.

[0063] The present invention provides more specific embodiments to describe the above method in detail, as follows:

[0064] Example 2:

[0065] Step 1: A continuous microwave signal is emitted through a microwave signal transmitter. When the microwave impedance of the object being tested is different from the microwave impedance of air, the object will generate a reflected wave. The reflected wave signal, or the signal of interference between the emitted wave and the incident wave, can be detected in the control system. Since the microwave impedance of the object being tested is not infinite, total microwave reflection cannot be achieved. Therefore, in the detection space, the microwaves are traveling and standing waves.

[0066] like Figure 2 As shown, the value at the microwave signal transmitting device is 0, the position of the object being detected, i.e., the distance between the object being detected and the microwave signal transmitting device, is L, and the position of the detection unit is z.

[0067] Let the microwave intensity emitted by the microwave signal transmitting device be Ae, the microwave frequency be ω, and the speed of light be c; the spatial distribution formula of the emitted wave Se(t,z) detected at position z at time t can be described as:

[0068] Let the reflection intensity be Ar, and the phase shift of the object being tested in response to microwaves be... The spatial distribution of the reflected wave Sr(t,z) detected at position z at time t can be described by the formula:

[0069]

[0070] Where |Γ| is the microwave reflection coefficient of the object being tested, and φ is the phase change caused by reflection; |Γ| and φ are related to the thickness, density, damage, etc. of the object being tested, and various types of damage to the object being tested can be detected by detecting the changes in |Γ| and φ.

[0071] Step 2: Read the envelope ||S0||(z) of the transmitted and reflected interference microwave signal obtained by the microwave detection unit at position z using the detection unit.

[0072] Assuming the transmitted signal strength remains constant (i.e., Ae remains constant), the variation of this signal at different locations on the object being detected is still affected by L. Minor sensor vibrations and the non-smoothness of the object's surface during measurement will cause variations in L. Furthermore, |Γ| and φ are also prone to mutual interference, leading to uncertainties in the detection results.

[0073] Step 3: Calculate ||S0|| based on ||S0||(z). 2 (z), ||S0|| 2 (z) includes a fixed part and a part that varies with space. Among them,

[0074]

[0075] Fixed part:

[0076] Amplitude variation with spatial variation:

[0077] Step 4: Based on Step 3, by moving the detection unit or the object being detected along the direction from the microwave signal transmitter to the object being detected, ||S0|| can be obtained. 2 Based on the spatial variation curve of (z), the fixed part of the detection unit at position z can be extracted. And the amplitude of spatial variation You can follow the formula Calculate |Γ| of the detected position on the object being inspected, as measured by the detection unit at position z. As the position of the detection unit moves, the detected position on the object being inspected also moves. The location of the damage is determined based on |Γ|.

[0078] Alternatively, you can continue to calculate the standing wave ratio (VSWR) using the formula VSWR = (1 + Г) / (1 - Г), and determine the location of the damage based on the VSWR.

[0079] Alternatively, the return loss RL can be calculated using the formula RL = -20lg(Г), and the location of the damage can be determined based on the return loss.

[0080] By moving the detection unit or the object being inspected, the phase shift value of the entire object can be scanned. By comparing the changes in damage parameters at different locations of the object, the locations where damage may occur can be identified, thus more effectively reducing detection noise.

[0081] Example 3

[0082] Step 4 in Example 2 has two drawbacks:

[0083] 1. When the complex reflection coefficient is low, ||S0|| 2 (z) The amplitude of the variation in the signal is low, and even a small measurement error can have a significant impact on the detection result.

[0084] 2. Scanning is required along the direction from the microwave signal transmitter to the object being detected, resulting in low detection efficiency.

[0085] The sensor positions that can be used are z1, z2, z3 and z4.

[0086] in: N is a positive integer from 1 to n.

[0087]

[0088]

[0089] Among them, ||S0||2 (t, z1) represents the ||S0|| measured by sensor z1 at time t. 2 ,||S0|| 2 (t, z2) represents the ||S0|| measured by sensor z2 at time t. 2 ,||S0|| 2 (t, z3) represents the ||S0|| measured by sensor z3 at time t. 2 ,||S0|| 2 (t, z4) represents the ||S0|| measured by sensor z4 at time t. 2 When the sensor at z1 and the sensor at z3 are 90° out of phase, for example:

[0090] but

[0091] but:

[0092] By fixing a microwave signal transmitting device and multiple detection units together to form a detection module, and when the relative positions of the detection modules meet the relevant constraints, the phase shift value of the entire object under test can be scanned by moving the detection unit or the object under test along a plane parallel to the direction from the microwave signal transmitting device to the object under test.

[0093] By comparing different positions of the detected object [||S0|| 2 (t,z1)-||S0|| 2 (t,z2)] 2 +[||S0|| 2 (t,z3)-||S0|| 2 (t,z4)] 2 By observing changes in these parameters, we can identify potential locations of damage to the object being inspected, thus more effectively reducing inspection noise.

[0094] Example 4

[0095] The excessive number of sensors used in Example 3 can easily lead to system complexity and, in extreme cases, may interfere with the spatial microwave distribution.

[0096] Two sensors with a spatial phase difference of 90° can be used, located at z1 and z3 respectively, as follows:

[0097]

[0098]

[0099] Among them, ||S0|| 2 (z1) represents the square of the envelope measured by sensor z1, ||S0||2 (z3) represents the square of the envelope measured by the z3 sensor. The basic characteristics of different detected objects can be identified by drawing a "z1-z3 diagram" in space.

[0100] The x-axis of the “z1-z3 graph” is ||S0|| 2 The measured result of (z1), with the ordinate being ||S0|| 2 The measured results of (z3) show that, for the same object being tested, the "z1-z3 diagram" is a circle in space, with the center point coordinates of [Ae(1+|Γ|), Ae(1+|Γ|)] and the radius of Ae·2·|Γ|. By analyzing this circle, the change of |Γ| can also be obtained, and the location of the damage can be determined based on |Γ|.

[0101] Alternatively, you can continue to calculate the standing wave ratio (VSWR) using the formula VSWR = (1 + Г) / (1 - Г), and determine the location of the damage based on the VSWR.

[0102] Alternatively, the return loss RL can be calculated using the formula RL = -20lg(Г), and the location of the damage can be determined based on the return loss.

[0103] By moving the detection unit or the object under test along a plane parallel to the direction from the microwave signal transmitter to the object under test, the phase shift value of the entire object under test can be scanned. By comparing the changes in damage parameters at different locations of the object under test, the locations where damage may occur can be identified, thus more effectively reducing detection noise.

[0104] Example 5

[0105] The difference between this embodiment and Embodiment 2 above is that this embodiment directly obtains the reflected wave signal and then obtains the envelope through other detection methods. Then proceed with steps 3 to 4 of Example 2.

[0106] Example 6

[0107] In Example 5, scanning is required along the direction from the microwave signal transmitting device to the object being detected, resulting in low detection efficiency.

[0108] Assuming the sensors are located at z1 and z3, when the sensor at z1 and the sensor at z3 are 90° out of phase, as shown below: This differs from the traveling and standing wave mode; 90° corresponds to a larger spatial distance.

[0109]

[0110]

[0111] but:

[0112] ||S0|| 4 (z3)+||S0|| 4 (z1)=Ae 2 ·|Γ| 2 .

[0113] By fixing microwave emission and multiple detection units together to form a detection module, and when the relative positions of the detection modules meet the relevant constraints in this embodiment, the phase shift value of the entire object under test can be scanned.

[0114] By moving the detection unit or the object under test along a plane parallel to the direction from the microwave signal transmitter to the object under test, the phase shift value of the entire object under test can be scanned. This allows for comparison of the phase shift value at different positions of the object under test. 4 (z3)+||S0|| 4 The change of (z1) can identify the location where the object being tested may be damaged, and can more effectively reduce the detection noise.

[0115] Example 7

[0116] The difference between this embodiment and embodiment 6 is that in this embodiment, ||S0|| is not calculated. 4 (z3)+||S0|| 4 (z1) can be obtained by drawing a “z1-z3 diagram” in space, and the subsequent steps are the same as in Example 4.

[0117] The present invention also provides a microwave detection system for the above-described method, comprising:

[0118] An envelope acquisition module is used to move the detection unit along a set direction to scan the object being detected, thereby obtaining the envelope of the microwave signal to be processed at different positions of the object being detected. The detection unit includes one sensor, two sensors with a spatial phase difference of 90 degrees, or four sensors. The four sensors include a first sensor, a second sensor, a third sensor, and a fourth sensor. The first sensor and the third sensor have a spatial phase difference of 90 degrees. The microwave signal to be processed is an interference signal or a microwave signal emitted by a microwave signal transmitting device reflected by the object being detected. The interference signal is a signal generated by the interference between the microwave signal emitted by the microwave signal transmitting device and the microwave signal emitted by the microwave signal transmitting device reflected by the object being detected.

[0119] The damage location determination module is used to determine the location of damage to the object being tested based on the envelope of the microwave signal to be processed at each location of the object being tested.

[0120] As an optional implementation, when the detection unit includes a sensor, and the microwave signal to be processed is an interference signal or a microwave signal emitted by a microwave signal transmitting device reflected by the object being detected, the damage location determination module specifically includes:

[0121] The first damage parameter determination unit is used to obtain the damage parameters at any location of the object being tested based on the envelope of the microwave signal to be processed at that location; the damage parameters are: standing wave ratio, microwave reflection coefficient, or return loss.

[0122] The first damage location determination unit is used to determine the location of damage to the object being tested based on the damage parameters at each location of the object being tested.

[0123] As an optional implementation, when the detection unit includes four sensors and the microwave signal to be processed is an interference signal, the damage location determination module specifically includes:

[0124] The first parameter value calculation unit is used to calculate, for any position of the detected object, the sum of the squares of the first difference at the position of the detected object and the sum of the squares of the second difference at the position of the detected object to obtain the parameter value at the position of the detected object; the first difference at the position of the detected object is the difference between the square of the envelope of the microwave signal to be processed at the position of the detected object collected by the first sensor and the square of the envelope of the microwave signal to be processed at the position of the detected object collected by the second sensor; the second difference at the position of the detected object is the difference between the square of the envelope of the microwave signal to be processed at the position of the detected object collected by the third sensor and the square of the envelope of the microwave signal to be processed at the position of the detected object collected by the fourth sensor.

[0125] The second damage location determination unit is used to determine the location of damage to the object being tested based on the parameter values ​​at each location of the object being tested.

[0126] As an optional implementation, when the detection unit includes two sensors with a spatial phase difference of 90 degrees and the microwave signal to be processed is an interference signal or a microwave signal emitted by a microwave signal transmitting device reflected by the object being detected, the damage location determination module specifically includes:

[0127] The plotting unit is used to plot a "z1-z3" graph at any location of the object being detected, with the square of the envelope of the microwave signal to be processed at the location of the object being detected collected by the first sensor as the horizontal axis and the square of the envelope of the microwave signal to be processed at the location of the object being detected collected by the second sensor as the vertical axis.

[0128] The second damage parameter determination unit is used to obtain the damage parameters at the location of the object being tested based on the "z1-z3" diagram at the location of the object being tested.

[0129] The third damage location determination unit is used to determine the location of damage to the object being tested based on the damage parameters at each location of the object being tested.

[0130] As an optional implementation, when the detection unit includes two sensors with a spatial phase difference of 90 degrees, and the microwave signal to be processed is a microwave signal emitted by a microwave signal transmitting device reflected by the object being detected; the damage location determination module specifically includes:

[0131] The second parameter value calculation unit is used to calculate, for any position of the object being detected, the sum of the fourth power of the envelope of the microwave signal to be processed at the position of the object being detected acquired by the first sensor and the fourth power of the envelope of the microwave signal to be processed at the position of the object being detected acquired by the second sensor to obtain the parameter value at the position of the object being detected.

[0132] The fourth damage location determination unit is used to determine the location of damage to the object being tested based on the parameter values ​​at each location of the object being tested.

[0133] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the systems disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple; relevant parts can be referred to the method section.

[0134] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A microwave detection method, characterized by, include: The detection unit moves along a predetermined direction to scan the object under test, obtaining the envelope of the microwave signal to be processed at different positions of the object under test. The detection unit includes one sensor, two sensors with a spatial phase difference of 90 degrees, or four sensors. The four sensors include a first sensor, a second sensor, a third sensor, and a fourth sensor. The first sensor and the third sensor have a spatial phase difference of 90 degrees. The microwave signal to be processed is an interference signal or a microwave signal emitted by a microwave signal emitting device reflected by the object under test. The interference signal is the signal generated by the interference between the microwave signal emitted by the microwave signal emitting device and the microwave signal emitted by the microwave signal emitting device reflected by the object under test. When the detection unit includes four sensors, the microwave signal to be processed is an interference signal. The location of damage to the object can be obtained by the envelope of the microwave signal to be processed at each location of the object being tested. When the detection unit includes a sensor, and the microwave signal to be processed is an interference signal or a microwave signal emitted by a microwave signal transmitting device reflected by the object being detected, the step of obtaining the location of damage to the object being detected based on the envelope of the microwave signal to be processed at each location of the object being detected specifically includes: For any location of the object being tested, the damage parameters at that location are obtained based on the envelope of the microwave signal to be processed at that location; the damage parameters are: standing wave ratio, microwave reflection coefficient, or return loss. The location of damage to the object under test is obtained based on the damage parameters at various locations of the object under test. When the detection unit includes four sensors and the microwave signal to be processed is an interference signal, the step of obtaining the location of damage to the object based on the envelope of the microwave signal to be processed at each location of the object specifically includes: For any position of the object being detected, the sum of the square of the first difference at that position and the square of the second difference at that position is calculated to obtain the parameter value at that position. The first difference at that position is the difference between the square of the envelope of the microwave signal to be processed at that position acquired by the first sensor and the square of the envelope of the microwave signal to be processed at that position acquired by the second sensor. The second difference at that position is the difference between the square of the envelope of the microwave signal to be processed at that position acquired by the third sensor and the square of the envelope of the microwave signal to be processed at that position acquired by the fourth sensor. The location of damage to the object can be determined based on the parameter values ​​at various locations of the object being tested. When the detection unit includes two sensors with a spatial phase difference of 90 degrees and the microwave signal to be processed is an interference signal or a microwave signal emitted by a microwave signal transmitting device reflected by the object being detected, the step of obtaining the location of damage to the object being detected based on the envelope of the microwave signal to be processed at each location of the object being detected specifically includes: For any position of the object being detected, a "z1-z3" graph is plotted with the square of the envelope of the microwave signal to be processed at the position of the object being detected collected by the first sensor as the horizontal axis and the square of the envelope of the microwave signal to be processed at the position of the object being detected collected by the second sensor as the vertical axis. The damage parameters at the location of the object under test are obtained from the "z1-z3" diagram at the location of the object under test. The location of damage to the object under test is obtained based on the damage parameters at various locations of the object under test. When the detection unit includes two sensors with a spatial phase difference of 90 degrees, and the microwave signal to be processed is a microwave signal emitted by a microwave signal transmitting device reflected by the object being detected; the step of obtaining the location of damage to the object being detected based on the envelope of the microwave signal to be processed at each location of the object being detected specifically includes: For any position of the object being detected, the fourth power of the envelope of the microwave signal to be processed at the position of the object being detected, collected by the first sensor, and the fourth power of the envelope of the microwave signal to be processed at the position of the object being detected, collected by the second sensor, are used to obtain the parameter value at the position of the object being detected. The location of damage to the tested object can be determined based on the parameter values ​​at each location.

2. A microwave detection system characterized by, include: An envelope acquisition module is used to move a detection unit along a set direction to scan the object being detected, obtaining the envelope of the microwave signal to be processed at different positions of the object. The detection unit includes one sensor, two sensors with a spatial phase difference of 90 degrees, or four sensors. The four sensors include a first sensor, a second sensor, a third sensor, and a fourth sensor. The first sensor and the third sensor have a spatial phase difference of 90 degrees. The microwave signal to be processed is an interference signal or a microwave signal emitted by a microwave signal transmitting device reflected by the object being detected. The interference signal is a signal generated by the interference between the microwave signal emitted by the microwave signal transmitting device and the microwave signal emitted by the microwave signal transmitting device reflected by the object being detected. When the detection unit includes four sensors, the microwave signal to be processed is an interference signal. The damage location determination module is used to determine the location of damage to the object being tested based on the envelope of the microwave signal to be processed at each location of the object being tested. When the detection unit includes a sensor, and the microwave signal to be processed is an interference signal or a microwave signal emitted by a microwave signal transmitting device reflected by the object being detected, the damage location determination module specifically includes: The first damage parameter determination unit is used to obtain the damage parameter at any location of the object being tested based on the envelope of the microwave signal to be processed at that location; the damage parameter is the standing wave ratio, microwave reflection coefficient, or return loss. The first damage location determination unit is used to determine the location of damage to the object being tested based on the damage parameters at each location of the object being tested. When the detection unit includes four sensors and the microwave signal to be processed is an interference signal, the damage location determination module specifically includes: The first parameter value calculation unit is used to calculate, for any position of the detected object, the sum of the square of the first difference at the position of the detected object and the square of the second difference at the position of the detected object to obtain the parameter value at the position of the detected object; the first difference at the position of the detected object is the difference between the square of the envelope of the microwave signal to be processed at the position of the detected object collected by the first sensor and the square of the envelope of the microwave signal to be processed at the position of the detected object collected by the second sensor; the second difference at the position of the detected object is the difference between the square of the envelope of the microwave signal to be processed at the position of the detected object collected by the third sensor and the square of the envelope of the microwave signal to be processed at the position of the detected object collected by the fourth sensor. The second damage location determination unit is used to determine the location of damage to the object being tested based on the parameter values ​​at each location of the object being tested. When the detection unit includes two sensors with a spatial phase difference of 90 degrees and the microwave signal to be processed is an interference signal or a microwave signal emitted by a microwave signal transmitting device reflected by the object being detected, the damage location determination module specifically includes: The plotting unit is used to plot a "z1-z3" graph at any position of the detected object, with the square of the envelope of the microwave signal to be processed at the position of the detected object collected by the first sensor as the horizontal axis and the square of the envelope of the microwave signal to be processed at the position of the detected object collected by the second sensor as the vertical axis. The second damage parameter determination unit is used to obtain the damage parameters at the location of the object being tested based on the "z1-z3" diagram at the location of the object being tested. The third damage location determination unit is used to determine the location of damage to the object being tested based on the damage parameters at each location of the object being tested. When the detection unit includes two sensors with a spatial phase difference of 90 degrees, and the microwave signal to be processed is a microwave signal emitted by a microwave signal transmitting device reflected by the object being detected; the damage location determination module specifically includes: The second parameter value calculation unit is used to calculate the fourth power of the envelope of the microwave signal to be processed at the location of the detected object acquired by the first sensor and the fourth power of the envelope of the microwave signal to be processed at the location of the detected object acquired by the second sensor for any location of the detected object, so as to obtain the parameter value at the location of the detected object. The fourth damage location determination unit is used to determine the location of damage to the object being tested based on the parameter values ​​at each location of the object being tested.

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