MUSIC damage location method based on self-excitation adaptive correction

Abstract

The application discloses a MUSIC damage positioning method based on self-excitation self-adaptive correction, which is used for improving algorithm positioning precision; in complex structure application, the structure has high anisotropy, in addition to the influence of sensor space layout error on array performance, the MUSIC damage positioning method has low precision. The array itself excitation array element is used as a correction source in the application, so that the additional correction source is avoided, the excitation array element has multiple directions relative to the sensor array, the actual time delay of each sensor array element in different directions is measured by receiving the self-excitation signal of the correction source; the distance from the self-excitation correction source to each sensor array element and the signal propagation speed are used to obtain the theoretical time delay from the self-excitation correction source to each sensor array element, and the array time delay error under the measurement of the self-excitation source is obtained by subtracting the actual time delay from the theoretical time delay; finally, in the search process, the time delay error of the corresponding self-excitation correction source direction is selected adaptively according to the search angle to correct the steering vector, so that the damage positioning precision can be improved.

Description

Technical Field

[0001] This invention belongs to the field of engineering structure health monitoring technology, and specifically relates to a MUSIC damage localization method based on self-excitation adaptive correction. Background Technology

[0002] Composite materials, with their advantages of high specific strength, high specific stiffness, corrosion resistance, fatigue resistance, and flexible design, have been widely used in aerospace structures. Compared with metallic materials, they can effectively reduce weight and significantly improve the aerodynamic characteristics and overall safety of aerospace structures. Currently, the application of composite materials in military and civilian aircraft both domestically and internationally is developing rapidly. However, aircraft composite material structures are highly susceptible to impacts from external objects during manufacturing, assembly, use, and maintenance. These impacts include collisions during transportation, dropped maintenance tools, and impacts from stones during takeoff and landing. These impacts can cause microscopic damage to the composite materials, such as dents, delamination, and cracks, which are not visible to the naked eye. This leads to a decline in the performance of the composite materials and seriously affects the safety of the structure. Therefore, damage diagnosis of composite material structures has become a very important topic in current structural health monitoring.

[0003] Waveguide-based structural health monitoring methods are considered one of the most promising monitoring methods for engineering applications due to their ability to propagate over long distances within structures and their high sensitivity to minute damage. Multiple Signal Classification (MUSIC) damage localization is a directional scanning and search method that utilizes the orthogonality of the signal and noise subspaces to perform unbiased estimation of signal characteristics. However, in complex composite material structures, the high anisotropy of the structure, coupled with sensor spatial layout errors affecting array performance, results in the array guide vector corresponding to the damage being non-orthogonal to the noise subspace, leading to a decrease in the accuracy of the MUSIC damage localization method. Therefore, it is essential to correct for various array error types to improve the accuracy of the MUSIC damage localization method. Summary of the Invention

[0004] To address the shortcomings of the prior art, the present invention aims to provide a MUSIC damage localization method based on self-excitation and adaptive correction, thereby solving the problem of time delay error in the signal received by each element of the sensing array due to the anisotropy of complex composite material structures and sensor spatial layout errors in the prior art; the method of the present invention improves the localization accuracy of MUSIC damage localization on complex composite material structures.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] The present invention provides a MUSIC damage localization method based on self-excitation adaptive correction, comprising the following steps:

[0007] (1) The sensor array receives self-excited correction source signals from different orientations: The excitation array itself is used as the correction source to excite the signal in the structure. The excitation array has multiple orientations relative to the sensor array. The sensor array is used to receive self-excited correction source signals from different orientations.

[0008] (2) Measure the actual time delay of the sensor array under the self-excitation correction source: Determine the arrival time of the self-excitation signal based on the position of the direct wave packet in the sensing signal, take q times the amplitude at the second peak of the direct wave packet as the threshold corresponding to the arrival time of the self-excitation signal, and then subtract the arrival time of each sensing signal from the arrival time of the sensing reference array element to obtain the actual time delay of the sensor array under the self-excitation correction source.

[0009] (3) Measure the theoretical time delay from the self-excited correction source to the sensor array: Average the guided wave propagation velocity values ​​of the monitoring frequency at intervals p from 0° to 360° on the structure to obtain the average guided wave propagation velocity values ​​in different directions. Divide the distance from the correction source to each sensor element by the average guided wave propagation velocity value to obtain the time from the self-excited correction source to each element of the sensor array. Then, take the difference between the time of each sensing signal and the time of the sensing reference element to obtain the theoretical time delay from the self-excited correction source to the sensor array.

[0010] (4) Obtain the array delay error under self-excitation correction source: Subtract the theoretical delay of the array from the actual delay to obtain the array delay error measured by the self-excitation source;

[0011] (5) Set the search start position and search step size: Set the search start position to (r s ,θ s That is, the distance r from the search position to the reference element in the sensor array. s The search position is θ relative to the sensor array. s The search step sizes for distance and angle are r, respectively. int and θ int ;where r s r int θ s θ int The value range is within the monitoring range;

[0012] (6) Obtaining damage scattering array signals: Under the structural health and damage monitoring states, the array elements in the excitation array sequentially excite the excitation signals into the structure, and the sensing array receives the response signals of the structure; the structural damage state sensing signal and the structural health state sensing signal under the same excitation sensing channel are subtracted to obtain the damage scattering array signals under each excitation source; based on the time delay difference of each excitation array element reaching the search position, the damage scattering array signals under each excitation source are shifted forward or backward and superimposed to obtain the damage scattering array signals.

[0013] (7) Calculate the noise subspace: Calculate the covariance matrix of the damaged scattering array signal, and then perform eigenvalue decomposition on the covariance matrix to obtain eigenvalues ​​arranged from large to small. The eigenvectors corresponding to the small eigenvalues ​​form the noise subspace, and the eigenvectors corresponding to the large eigenvalues ​​form the signal subspace.

[0014] (8) Adaptive selection of self-excitation correction source to correct the steering vector: The angle during the search is subtracted from the azimuth angles of multiple self-excitation correction sources, and the array delay error of the corresponding azimuth correction source with the smallest absolute value of the difference is used to correct the steering vector.

[0015] (9) Determine the damage location: Calculate the search space spectrum and image it using the corrected guide vector. The peak point of the imaging result is the damage location.

[0016] Further, step (1) includes an excitation array E and a sensing array T, each array consisting of 2K+1 array elements arranged at equal intervals. Each array element in the excitation array E serves as a correction source and is used with E... g Indicated by T; each element in the sensing array T is represented by T. g Let g represent the array element number, and g = -K, -(K-1), ..., 0, ..., K-1, K.

[0017] Furthermore, in step (3), each element E of the excitation array E... g The distance between the sensor array T and the reference element T0 is L i Then each array element T g The theoretical time delay Δt relative to the reference element T0 g :

[0018]

[0019] In the formula, d is the distance between adjacent array elements, and θ r For connecting array element E g The angle formed by the line of the reference element T0 of the sensing array T and the X-axis, v is the speed of signal propagation, and g = -K, -(K-1), ..., 0, ..., K-1, K.

[0020] Furthermore, in step (4), each excitation element in the excitation array E is used as a correction source to obtain the array delay error Y from different directions due to signal transmission and reception factors. T (θ):

[0021]

[0022] In the formula, diag{} represents forming a diagonal matrix from the array elements, Δt g ′ represents each array element T gRelative to the actual time delay of the reference array element T0, e is the natural constant, j is the imaginary unit, and ω represents the frequency domain.

[0023] Furthermore, in step (6), the focused and enhanced damage scattering array signal G', obtained using the coherent superposition method, is:

[0024]

[0025] In the formula, H(t) represents the structure under healthy conditions based on array element E. g The response signal of the sensing array at time D(t) represents the response signal based on array element E under structural damage conditions. g The sensor array response signal at that time; G g The sensor array T is based on array element E. g The obtained damage scattering array signal, ω0 is the center frequency of signal propagation, and t is the relative time delay from each element in the excitation array E to the search position.

[0026] Furthermore, the covariance matrix C of the damaged scattering array signal in step (7) is:

[0027]

[0028] In the formula, (G') H G' is the Hermitian transpose, and Y is the signal sampling length;

[0029] Perform eigenvalue decomposition on the covariance matrix C:

[0030]

[0031] In the formula, Z S Z η These are the signal subspace and the noise subspace, respectively. S Σ η These are the large eigenvalues ​​corresponding to the signal subspace and the small eigenvalues ​​corresponding to the noise subspace, respectively.

[0032] Furthermore, in step (8), the search angle is θ, and the azimuth angle of each self-excitation correction source is θ. i The difference between the search angle and the azimuth angle of each self-excitation correction source is Δθ. i :

[0033] Δθ i =|θ-θ i |

[0034] The array time delay error measured by the corresponding azimuth self-excitation correction source with the smallest absolute value of the difference is used to correct the steering vector;

[0035] A'(r,θ)=ΥT (θ)A(r,θ)

[0036] In the formula, A'(r,θ) is the corrected steering vector.

[0037] Furthermore, in step (9), the search space spectrum J is calculated. MUSIC2 (r,θ):

[0038]

[0039] Imaging the search spatial spectrum reveals a distinct peak, which represents the location of the MUSIC damage based on self-excitation adaptive correction.

[0040] The beneficial effects of this invention are:

[0041] Traditional MUSIC algorithms typically require additional calibration sources to correct the steering vector, which not only increases system complexity but may also introduce additional errors. This invention, however, uses the array elements themselves and selects multiple self-excited calibration sources to correct the array steering vector. This method not only avoids the need for additional calibration sources in the structure but also adaptively corrects the steering vector, thereby improving positioning accuracy. Attached Figure Description

[0042] Figure 1 This is a flowchart of the method of the present invention;

[0043] Figure 2 This is a schematic diagram of the composite material structure and array arrangement in the embodiment;

[0044] Figure 3 The array signal diagram in this embodiment uses the array's own excitation source as the correction source.

[0045] Figure 4 This is a graph showing the array delay error results measured by the array self-excitation source in the embodiment;

[0046] Figure 5 This is a schematic diagram of the damage location in the embodiment;

[0047] Figure 6 The image shows the damage imaging results of the MUSIC damage localization method based on self-excitation adaptive correction in the embodiment. Detailed Implementation

[0048] To facilitate understanding by those skilled in the art, the present invention will be further described below with reference to embodiments and accompanying drawings. The content mentioned in the embodiments is not intended to limit the present invention.

[0049] Reference Figure 1As shown, the present invention provides a MUSIC damage localization method based on self-excitation adaptive correction, comprising the following steps:

[0050] (1) The sensor array receives self-excited correction source signals from different orientations: The excitation array itself is used as the correction source to excite the signal in the structure. The excitation array has multiple orientations relative to the sensor array. The sensor array is used to receive self-excited correction source signals from different orientations.

[0051] (2) Measure the actual time delay of the sensor array under the self-excitation correction source: Determine the arrival time of the self-excitation signal based on the position of the direct wave packet in the sensing signal, take q times the amplitude at the second peak of the direct wave packet as the threshold corresponding to the arrival time of the self-excitation signal, and then subtract the arrival time of each sensing signal from the arrival time of the sensing reference array element to obtain the actual time delay of the sensor array under the self-excitation correction source.

[0052] (3) Measure the theoretical time delay from the self-excited correction source to the sensor array: Average the guided wave propagation velocity values ​​of the monitoring frequency at intervals p from 0° to 360° on the structure to obtain the average guided wave propagation velocity values ​​in different directions. Divide the distance from the correction source to each sensor element by the average guided wave propagation velocity value to obtain the time from the self-excited correction source to each element of the sensor array. Then, take the difference between the time of each sensing signal and the time of the sensing reference element to obtain the theoretical time delay from the self-excited correction source to the sensor array.

[0053] (4) Obtain the array delay error under self-excitation correction source: Subtract the theoretical delay of the array from the actual delay to obtain the array delay error measured by the self-excitation source;

[0054] (5) Set the search start position and search step size: Set the search start position to (r s ,θ s That is, the distance r from the search position to the reference element in the sensor array. s The search position is θ relative to the sensor array. s The search step sizes for distance and angle are r, respectively. int and θ int ;where r s r int θ s θ int The value range is within the monitoring range;

[0055] (6) Obtaining damage scattering array signals: Under the structural health and damage monitoring states, the array elements in the excitation array sequentially excite the excitation signals into the structure, and the sensing array receives the response signals of the structure; the structural damage state sensing signal and the structural health state sensing signal under the same excitation sensing channel are subtracted to obtain the damage scattering array signals under each excitation source; based on the time delay difference of each excitation array element reaching the search position, the damage scattering array signals under each excitation source are shifted forward or backward and superimposed to obtain the damage scattering array signals.

[0056] (7) Calculate the noise subspace: Calculate the covariance matrix of the damaged scattering array signal, and then perform eigenvalue decomposition on the covariance matrix to obtain eigenvalues ​​arranged from large to small. The eigenvectors corresponding to the small eigenvalues ​​form the noise subspace, and the eigenvectors corresponding to the large eigenvalues ​​form the signal subspace.

[0057] (8) Adaptive selection of self-excitation correction source to correct the steering vector: The angle during the search is subtracted from the azimuth angles of multiple self-excitation correction sources, and the array delay error of the corresponding azimuth correction source with the smallest absolute value of the difference is used to correct the steering vector.

[0058] (9) Determine the damage location: Calculate the search space spectrum and image it using the corrected guide vector. The peak point of the imaging result is the damage location.

[0059] In the example:

[0060] The object in this embodiment is a reinforced composite material structure with dimensions of 90cm × 90cm × 0.3cm, such as... Figure 2 As shown, an excitation array E and a sensing array T are arranged on the surface of the structure. There are two reinforcing ribs in the middle of the composite material plate, each 4 cm wide. The distance between the arrays is set to 19.8 cm. The excitation array E and the sensing array T are connected by the reinforcing ribs. Each array has 7 elements, and the spacing between adjacent elements is 1.2 cm.

[0061] The specific implementation method for damage localization in composite material structures is as follows:

[0062] 1. Measure array delay error using its own excitation array elements;

[0063] (1) The excitation array E itself is used as the correction source to excite the signal in the structure. The excitation array element has multiple orientations relative to the sensor array T. The sensor array is used to receive the self-excited correction source signals in different orientations.

[0064] (2) Determine the arrival time of the self-excitation signal based on the position of the direct wave packet in the sensing signal, such as Figure 3As shown, 0.6 times the amplitude at the sub-peak of the direct-arrival wave packet is taken as the threshold corresponding to the arrival time of the self-excited signal. Then, the arrival time of each sensing signal is subtracted from the arrival time of the sensing reference array element to obtain the actual time delay of the sensing array under the self-excited correction source.

[0065] (3) The average wave propagation velocity values ​​of the guided waves at monitoring frequencies with intervals of 30° from 0° to 360° on the structure are averaged to obtain the average wave propagation velocity values ​​in different directions. The time from the self-excited correction source to each element of the sensing array is obtained by dividing the distance from the correction source to each element of the sensing array by the average wave propagation velocity value. Then, the time difference between each sensing signal and the time of the sensing reference element is calculated to obtain the theoretical time delay from the self-excited correction source to the sensing array.

[0066] Each element E of the excitation array E g The distance between the sensor array T and the reference element T0 is L i Then each array element T g The theoretical time delay Δt relative to the reference element T0 g :

[0067]

[0068] In the formula, d is the distance between adjacent array elements, and θ r For connecting array element E g The angle formed by the line of the reference element T0 of the sensing array T and the X-axis, v is the speed of signal propagation, g = -3, -2, ..., 0, ..., 2, 3;

[0069] (4) Obtain the array delay error under self-excitation correction source: Subtract the theoretical delay of the array from the actual delay to obtain the array delay error measured by the self-excitation source:

[0070] Using each excitation element in the excitation array E as a correction source, the array delay error Υ due to signal transmission and reception factors from different directions is obtained. T (θ):

[0071]

[0072] In the formula, diag{} represents forming a diagonal matrix from the array elements, Δt g ′ represents each array element T g Relative to the actual time delay of the reference array element T0, e is the natural constant, j is the imaginary unit, and ω represents the frequency domain. For example... Figure 4 The figure shows the array delay error under each excitation correction source.

[0073] 2. Set the search start position and search step size;

[0074] The search start position is set to (1mm, 1°), which means that the distance from the search position to the reference element in the sensor array is 1mm, the direction of the search position relative to the sensor array is 1°, and the search step size for distance and angle is 1mm and 1°, respectively.

[0075] 3. Acquire the damage scattering array signal;

[0076] Under structurally healthy conditions, the array elements E in the array are excited sequentially. -3 An excitation signal is generated in the structure via E3, and the sensor array receives the response signal from the structure; during damage monitoring, such as Figure 5 As shown, the array elements E in the array are excited sequentially. -3 An excitation signal is generated in the structure via E3, and the sensor array receives the response signal of the structure. The difference between the structural damage state sensing signal and the structural health state sensing signal under the same excitation sensing channel is used to obtain the damage scattering array signal under each excitation source. Based on the time delay difference of each excitation array element reaching the search position, the damage scattering array signals under each excitation source are shifted forward or backward and superimposed to obtain the damage scattering array signal.

[0077] Using the coherent superposition method, the focused and enhanced damage scattering array signal G' is:

[0078]

[0079] In the formula, H(t) represents the structure under healthy conditions based on array element E. g The response signal of the sensing array at time D(t) represents the response signal based on array element E under structural damage conditions. g The sensor array response signal at that time; G g The sensor array T is based on array element E. g The obtained damage scattering array signal, ω0 is the center frequency of signal propagation, and t is the relative time delay from each element in the excitation array E to the search position.

[0080] 4. Calculate the noise subspace;

[0081] Calculate the covariance matrix of the damaged scattering array signal, then perform eigenvalue decomposition on the covariance matrix to obtain eigenvalues ​​arranged in descending order. The eigenvectors corresponding to the smaller eigenvalues ​​form the noise subspace, and the eigenvectors corresponding to the larger eigenvalues ​​form the signal subspace.

[0082] The covariance matrix C of the damaged scattering array signal:

[0083]

[0084] In the formula, (G') H G' is the Hermitian transpose, and Y is the signal sampling length;

[0085] Perform eigenvalue decomposition on the covariance matrix C:

[0086]

[0087] In the formula, Z S Z η These are the signal subspace and the noise subspace, respectively. S Σ η These are the large eigenvalues ​​corresponding to the signal subspace and the small eigenvalues ​​corresponding to the noise subspace, respectively.

[0088] 5. Adaptively select self-excitation correction source to correct the steering vector;

[0089] The angle during the search is subtracted from the azimuth angles of multiple self-excited correction sources. The array delay error measured by the corresponding azimuth correction source with the smallest absolute value of the difference is selected to correct the steering vector.

[0090] The search angle is θ, and the azimuth angle of each self-excitation correction source is θ. i The difference between the search angle and the azimuth angle of each self-excitation correction source is Δθ. i :

[0091] Δθ i =|θ-θ i |

[0092] The array time delay error measured by the corresponding azimuth self-excitation correction source with the smallest absolute value of the difference is used to correct the steering vector;

[0093] A'(r,θ)=Υ T (θ)A(r,θ)

[0094] In the formula, A'(r,θ) is the corrected steering vector.

[0095] 6. Determine the location of the injury;

[0096] The search space spectrum was calculated and imaged using the corrected steering vector; the peak points in the imaging results represent the damage locations.

[0097] Calculate the search space spectrum J MUSIC2 (r,θ):

[0098]

[0099] Imaging the search spatial spectrum reveals a distinct peak, such as... Figure 6 As shown, it represents the MUSIC damage location based on self-excitation adaptive correction.

[0100] This invention has many specific applications. The above description is only a preferred embodiment of this invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of this invention, and these improvements should also be considered within the scope of protection of this invention.

Claims

1. A MUSIC damage localization method based on self-excitation adaptive correction, characterized in that, The steps are as follows: (1) The sensor array receives self-excited correction source signals from different orientations: The excitation array itself is used as the correction source to excite the signal in the structure. The excitation array has multiple orientations relative to the sensor array. The sensor array is used to receive self-excited correction source signals from different orientations. (2) Measure the actual time delay of the sensor array under the self-excitation correction source: Determine the arrival time of the self-excitation signal based on the position of the direct wave packet in the sensing signal, take q times the amplitude at the second peak of the direct wave packet as the threshold corresponding to the arrival time of the self-excitation signal, and then subtract the arrival time of each sensing signal from the arrival time of the sensing reference array element to obtain the actual time delay of the sensor array under the self-excitation correction source. (3) Measure the theoretical time delay from the self-excited correction source to the sensor array: average the guided wave propagation velocity values ​​of the monitoring frequency at intervals p from 0° to 360° on the structure to obtain the average guided wave propagation velocity values ​​in different directions. Divide the distance from the correction source to each sensor element by the average guided wave propagation velocity value to obtain the time from the self-excited correction source to each element of the sensor array. Then, take the difference between the time of each sensing signal and the time of the sensing reference element to obtain the theoretical time delay from the self-excited correction source to the sensor array. (4) Obtain the array delay error under self-excitation correction source: Subtract the theoretical delay of the array from the actual delay to obtain the array delay error measured by the self-excitation source; (5) Set the search start position and search step size: Set the search start position to That is, the distance from the search position to the reference element in the sensor array is The search position is relative to the direction of the sensor array. The search step sizes for distance and angle are respectively and ; (6) Acquiring damage scattering array signals: Under the structural health and damage monitoring conditions, the array elements in the excitation array sequentially excite excitation signals into the structure, and the sensing array receives the response signals of the structure; The damage scattering array signal under each excitation source is obtained by subtracting the structural damage state sensing signal and the structural health state sensing signal under the same excitation sensing channel. Based on the time delay difference of each excitation array element reaching the search position, the damage scattering array signal under each excitation source is shifted forward or backward and superimposed to obtain the damage scattering array signal. (7) Calculate the noise subspace: Calculate the covariance matrix of the damaged scattering array signal, and then perform eigenvalue decomposition on the covariance matrix to obtain eigenvalues ​​arranged from large to small. The eigenvectors corresponding to the small eigenvalues ​​form the noise subspace, and the eigenvectors corresponding to the large eigenvalues ​​form the signal subspace. (8) Adaptive selection of self-excitation correction source to correct the steering vector: The angle during the search is subtracted from the azimuth angles of multiple self-excitation correction sources, and the array delay error measured by the corresponding azimuth correction source with the smallest absolute value of the difference is selected to correct the steering vector; (9) Determine the damage location: Calculate the search space spectrum and image it using the corrected guide vector. The peak point of the imaging result is the damage location. Step (1) includes an excitation array E and a sensing array T. Each array consists of 2K+1 array elements, which are arranged at equal intervals. Each array element in the excitation array E serves as a correction source and is used with E... g Indicated by T; each element in the sensing array T is represented by T. g Let g represent the array element number, g=-K,-(K-1),…,0,…,K-1,K. Element T0 with the number 0 is the sensing reference element and is the central element of the sensing array.

2. The MUSIC damage localization method based on self-excitation adaptive correction according to claim 1, characterized in that, In step (3), each element E of the excitation array E g The distance between the sensor array T and the reference element T0 is L i Then each array element T g The theoretical time delay relative to the reference element T0 : ； In the formula, d is the distance between adjacent array elements. For connecting array element E g The angle formed by the line of the reference element T0 of the sensing array T and the X-axis, v is the speed of signal propagation, and g = -K, -(K-1), ..., 0, ..., K-1, K.

3. The MUSIC damage localization method based on self-excitation adaptive correction according to claim 2, characterized in that, In step (4), each excitation element in the excitation array E is used as a correction source to obtain array delay errors from different directions caused by signal transmission and reception factors. : ； In the formula, diag{} represents forming a diagonal matrix from the array elements. For each array element T g Relative to the actual time delay of the reference array element T0, e is the natural constant, and j is the imaginary unit. Represents the frequency domain. The angle used during the search.

4. The MUSIC damage localization method based on self-excitation adaptive correction according to claim 3, characterized in that, In step (6), the coherent superposition method is used to focus and enhance the damage scattering array signal. for: ； In the formula, H(t) represents the structure under healthy conditions based on array element E. g The response signal of the sensing array at time D(t) represents the response signal based on array element E under structural damage conditions. g The sensor array response signal at that time; The sensor array T is based on array element E. g The obtained damage scattering array signal, Let t be the center frequency of signal propagation, and t be the relative time delay from each element in the excitation array E to the search position.

5. The MUSIC damage localization method based on self-excitation adaptive correction according to claim 4, characterized in that, The covariance matrix of the damaged scattering array signal in step (7) : ； In the formula, for The Hermitian transpose, where Y is the signal sampling length; For covariance matrix Perform eigenvalue decomposition: ； In the formula, , These are the signal subspace and the noise subspace, respectively. , These are the large eigenvalues ​​corresponding to the signal subspace and the small eigenvalues ​​corresponding to the noise subspace, respectively.

6. The MUSIC damage localization method based on self-excitation adaptive correction according to claim 5, characterized in that, In step (8), the angle during the search is The azimuth angle of each self-excitation correction source is The difference between the search angle and the azimuth angle of each self-excitation correction source is... : ； The array time delay error measured by the corresponding azimuth self-excitation correction source with the smallest absolute value of the difference is used to correct the steering vector; ； In the formula, The corrected guide vector; For search location The original guidance vector of the sensor array; The distance from the search location to the reference element T0 of the sensor array. The angle used during the search.

7. The MUSIC damage localization method based on self-excitation adaptive correction according to claim 6, characterized in that, In step (9), the search space spectrum is calculated. : ； Imaging the search spatial spectrum reveals a distinct peak, which represents the location of the MUSIC damage based on self-excitation adaptive correction.

Images