Spacecraft structure leakage positioning method based on capacitive micro-electromechanical ultrasonic array
By using frequency domain signal processing and sparse basis matrix reconstruction of capacitive microelectromechanical ultrasonic arrays, the problems of high cost and difficult deployment of traditional acoustic sensor arrays on spacecraft have been solved. This has enabled high-precision location and stable detection of spacecraft leaks, simplified the system structure, and improved reliability.
Patent Information
- Application Number
- CN202610079832.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-01-21
- Publication Date
- 2026-05-15
AI Technical Summary
Traditional spacecraft leak location methods based on acoustic sensor arrays are costly and complex, and are difficult to deploy on a large scale on spacecraft. They cannot meet the requirements of lightweight and low power consumption, and the location performance is difficult to maintain stability in complex acoustic fields.
A capacitive microelectromechanical ultrasonic array is adopted. Frequency domain signals are collected by randomly selecting array elements, and the wavenumber domain spectrum of the leakage sound field is reconstructed. The sparse basis matrix and basis tracking noise reduction algorithm are used for localization, which reduces the number of array elements and simplifies the system structure. The air coupling method is easy to operate, and the random distribution of array elements enhances fault tolerance.
It achieves high-precision location of spacecraft structural leaks, reduces system cost and complexity, improves system integrability and engineering applicability, has excellent anti-interference capabilities and positioning stability, and can work reliably in complex environments.
Smart Images
Figure CN122042151A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of non-destructive testing technology, and specifically relates to a method for locating leaks in spacecraft structures based on a capacitive microelectromechanical ultrasonic array. Background Technology
[0002] With the increasing frequency of human space activities, space debris is accumulating in Earth's orbit, creating a growing space junk environment. If a spacecraft in orbit is struck by such high-speed debris, it is highly susceptible to structural damage to its cabin and leakage of sealed gases, thus seriously threatening the continued safe operation of the spacecraft and even the lives of astronauts. Therefore, developing reliable technologies capable of rapidly detecting and accurately locating leaks in spacecraft in orbit has become a crucial element in ensuring the success of manned space missions, possessing significant engineering application value and representing an urgent practical need.
[0003] However, due to the vacuum environment, complex bulkhead structure, and random leaks in orbiting spacecraft, leak detection in this environment presents numerous technical challenges. These factors intertwine to form the core technical difficulties in on-orbit leak detection and location. Acoustic detection methods offer unique advantages: the interaction between turbulence and the structure during a leak radiates broadband ultrasonic signals that can penetrate the structure and be captured by sensors; analysis of these acoustic signals not only determines the occurrence of a leak but also enables the location and quantitative assessment of the leak source using array signal processing technology. Therefore, leak location methods based on acoustic sensor arrays are considered the most promising direction for solving the problem of on-orbit leak location in spacecraft.
[0004] Traditional leak location methods based on acoustic sensor arrays typically rely on high-density arrays consisting of dozens or even hundreds of elements. This directly leads to enormous hardware costs, complexity, and power consumption for multi-channel high-speed synchronous data acquisition systems. It not only increases the size and weight of the payload but also contradicts the stringent requirements of spacecraft for lightweight, low-power, and high-reliability equipment. More importantly, the deployment and maintenance of such high-density arrays are highly impractical in real-world aerospace engineering. Spacecraft have complex structures and extremely limited space and payload resources, making large-scale deployment of sensors and associated cables difficult. Therefore, how to significantly reduce the number of physical channels in the array and lower system complexity without sacrificing positioning performance has become a core problem that acoustic array leak location technology must overcome. Summary of the Invention
[0005] To address the aforementioned problems, the present invention aims to provide a method for locating leaks in spacecraft structures based on a capacitive microelectromechanical ultrasonic array.
[0006] To achieve the above objectives, the spacecraft structure leak location method based on a capacitive microelectromechanical ultrasonic array provided by the present invention includes the following steps performed in sequence:
[0007] 1) The number of array elements deployed on the surface of the structure under test where the leak source is located on the spacecraft is [number missing]. Capacitive microelectromechanical ultrasonic array;
[0008] 2) Design the operating mode of the above-mentioned capacitive microelectromechanical ultrasonic array. Within the capacitive microelectromechanical ultrasonic array, randomly select... Each array element collects frequency domain signals;
[0009] 3) Reconstruct the wavenumber domain spectrum of the complete leakage sound field using the above frequency domain signals;
[0010] 4) Based on the above wavenumber domain spectrum, the direction of leakage is identified to obtain the propagation axis of the leakage acoustic signal;
[0011] 5) Move the capacitive microelectromechanical ultrasonic array to two different positions on the surface of the structure to be tested, and then collect the corresponding frequency domain signals according to the method in step 2). Repeat steps 3) to 4) to obtain the wavenumber domain spectrum of each, and then extract the propagation direction axis corresponding to the energy maximum point of the wavenumber domain spectrum.
[0012] 6) After obtaining the three propagation direction axes, a triangular region enclosed by these three propagation direction axes is obtained; finally, the coordinates of the center of the inscribed circle of this triangular region are used as the estimated value of the leakage source location, thereby achieving accurate positioning of the leakage source.
[0013] In step 2), the The frequency domain signal of each array element is ,in, Indicates the randomly selected first... The coordinate positions of each array element in the two-dimensional plane The frequency is represented, and the relative coordinates of these array elements are labeled as follows: ,in , .
[0014] In step 3), the method for reconstructing the wavenumber domain spectrum of the complete leakage sound field using the aforementioned frequency domain signal is as follows:
[0015] Let the all-zero matrix be... For each Let column index Then the all-zero matrix The Line number The column elements are set to 1, and the resulting matrix is denoted as the observation matrix. Therefore, the observation matrix Only one Each element is 1, and each row contains exactly one element;
[0016] Selecting sparse basis matrices Two-dimensional inverse Fourier transform operator ,make This enables the mapping from the acquired frequency domain signal to the reconstructed wavenumber domain spectrum;
[0017] observation matrix With sparse basis matrix The sensing matrix is constructed by multiplication. Then based on the sensor matrix and frequency domain signals The following compressed sensing model is established:
[0018] ;
[0019] Then, the basis pursuit noise reduction algorithm is used to solve the compressed sensing model to obtain the wavenumber domain spectrum of the complete leakage sound field. .
[0020] In step 4), the method for identifying the leakage direction based on the aforementioned wavenumber domain spectrum and obtaining the propagation direction axis of the leakage acoustic signal is as follows: by extracting the wavenumber domain spectrum. The point of maximum energy in the signal can be used to determine the direction of the corresponding wavenumber vector, and thus the propagation direction axis of the leakage sound signal can be obtained. .
[0021] The spacecraft structure leakage localization method based on capacitive microelectromechanical ultrasonic array provided by this invention has the following beneficial effects:
[0022] 1. This invention can achieve high-precision location of leaks in spacecraft structures, and still has excellent anti-interference ability and positioning stability in complex acoustic field environments.
[0023] 2. This invention significantly reduces the number of array elements in a capacitive microelectromechanical ultrasonic array that operates simultaneously, thereby greatly simplifying the system architecture and reducing the number of signal acquisition and processing units while ensuring performance. This reduces the overall cost and improves the system's integrability and engineering applicability.
[0024] 3. The capacitive microelectromechanical ultrasonic array adopts an air coupling working mode, which does not require direct contact with the structure under test, making it easy to operate and allowing for rapid repositioning and retesting.
[0025] 4. The randomly distributed array element cooperative working mode designed in this invention enhances the system's fault tolerance to partial array element failure or signal obstruction. Even when a few array elements are subject to noise interference or hardware failure, stable positioning can still be achieved through the reconstruction algorithm, improving reliability in complex industrial environments. Attached Figure Description
[0026] Figure 1 The flowchart of the spacecraft structure leakage localization method based on capacitive microelectromechanical ultrasonic array provided by the present invention is shown.
[0027] Figure 2 This is a schematic diagram of the CMUT array layout for spacecraft leak detection.
[0028] Figure 3 This is a schematic diagram of the collaborative working mode of sparsely distributed array elements.
[0029] Figure 4 (a) and (b) are the reconstructed wavenumber domain spectra after detection at 90° and 130° directions of the leakage source, respectively.
[0030] Figure 5 This is a schematic diagram of the leakage source location principle. Detailed Implementation
[0031] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.
[0032] like Figure 1 As shown, the spacecraft structure leak location method based on a capacitive microelectromechanical ultrasonic array provided by the present invention includes the following steps performed in sequence:
[0033] 1) Deploy an 8×8 capacitive microelectromechanical ultrasonic (CMUT) array on the surface of the structure under test where the leak source is located on the spacecraft, such as... Figure 2 As shown;
[0034] Since the capacitive microelectromechanical ultrasonic array is an air-coupled ultrasonic transducer, no coupling agent is required. Therefore, effective acoustic coupling can be achieved simply by gently attaching it to the surface of the structure to be tested.
[0035] 2) Design the operating mode of the above-mentioned capacitive microelectromechanical ultrasonic array. Randomly select 16 elements from the 8×8 array elements of the capacitive microelectromechanical ultrasonic array to acquire frequency domain signals. ,in, Indicates the randomly selected first... The coordinate positions of each array element in the two-dimensional plane The frequency is represented, and the relative coordinates of these 16 array elements are marked as follows: ,like Figure 3 As shown, where , .
[0036] 3) Reconstruct the wavenumber domain spectrum of the complete leakage sound field using the above frequency domain signals;
[0037] Let the all-zero matrix be... For each Let column index Then the all-zero matrix The Line number The column elements are set to 1, and the resulting matrix is denoted as the observation matrix. Therefore, the observation matrix There are exactly 16 elements that are 1, and each row contains exactly one element.
[0038] Selecting sparse basis matrices Two-dimensional inverse Fourier transform operator , that is to say This enables the mapping from the acquired frequency domain signal to the reconstructed wavenumber domain spectrum;
[0039] observation matrix With sparse basis matrix The sensing matrix is constructed by multiplication. Then based on the sensor matrix and frequency domain signals The following compressed sensing model is established:
[0040] ;
[0041] Then, the basis pursuit noise reduction (BPDN) algorithm is used to solve the compressed sensing model to obtain the wavenumber domain spectrum of the complete leakage sound field. , represented as:
[0042] .
[0043] 4) Identify the leakage direction based on the aforementioned wavenumber domain spectrum;
[0044] The intensity distribution of the wavenumber domain spectrum reflects the propagation characteristics of the sound field in space. By extracting the wavenumber domain spectrum... The point of maximum energy in the signal can be used to determine the direction of the corresponding wavenumber vector, and thus the propagation direction axis of the leakage sound signal can be obtained. ,like Figure 4 As shown, this enables accurate identification of the leakage direction.
[0045] 5) Move the capacitive microelectromechanical ultrasonic array to two different positions on the surface of the structure under test, and then collect the corresponding frequency domain signals according to the method in step 2), as follows:
[0046] ;
[0047] ;
[0048] Repeat steps 3) to 4) to obtain their respective wavenumber domain spectra in turn. , , represented as:
[0049] ;
[0050] ;
[0051] Then extract the propagation direction axis corresponding to the point of maximum energy in the wavenumber domain spectrum. , .
[0052] 6) Obtain the three propagation direction axes , , Then, a triangular region enclosed by these three propagation axes is obtained, such as... Figure 5 As shown; finally, the coordinates of the inscribed circle of this triangular region are used. This serves as an estimate of the leak source's location, thereby enabling precise localization of the leak source.
Claims
1. A method for locating leaks in spacecraft structures based on a capacitive microelectromechanical ultrasonic array, characterized in that: The method includes the following steps performed in sequence: 1) The number of array elements deployed on the surface of the structure under test where the leak source is located on the spacecraft is [number missing]. Capacitive microelectromechanical ultrasonic array; 2) Design the operating mode of the above-mentioned capacitive microelectromechanical ultrasonic array. Within the capacitive microelectromechanical ultrasonic array, randomly select... Each array element collects frequency domain signals; 3) Reconstruct the wavenumber domain spectrum of the complete leakage sound field using the above frequency domain signals; 4) Based on the above wavenumber domain spectrum, the direction of leakage is identified to obtain the propagation axis of the leakage acoustic signal; 5) Move the capacitive microelectromechanical ultrasonic array to two different positions on the surface of the structure to be tested, and then collect the corresponding frequency domain signals according to the method in step 2). Repeat steps 3) to 4) to obtain the wavenumber domain spectrum of each, and then extract the propagation direction axis corresponding to the energy maximum point of the wavenumber domain spectrum. 6) After obtaining the three propagation direction axes, a triangular region enclosed by these three propagation direction axes is obtained; finally, the coordinates of the center of the inscribed circle of this triangular region are used as the estimated value of the leakage source location, thereby achieving accurate positioning of the leakage source.
2. The spacecraft structural leakage location method based on a capacitive microelectromechanical ultrasonic array according to claim 1, characterized in that: In step 2), the The frequency domain signal of each array element is ,in, Indicates the randomly selected first... The coordinate positions of each array element in the two-dimensional plane The frequency is represented, and the relative coordinates of these array elements are labeled as follows: ,in , .
3. The spacecraft structural leakage location method based on a capacitive microelectromechanical ultrasonic array according to claim 1, characterized in that: In step 3), the method for reconstructing the wavenumber domain spectrum of the complete leakage sound field using the aforementioned frequency domain signal is as follows: Let the all-zero matrix be... For each Let column index Then the all-zero matrix The Line number The column elements are set to 1, and the resulting matrix is denoted as the observation matrix. Therefore, the observation matrix Only one Each element is 1, and each row contains exactly one element; Selecting sparse basis matrices Two-dimensional inverse Fourier transform operator ,make This enables the mapping from the acquired frequency domain signal to the reconstructed wavenumber domain spectrum; observation matrix With sparse basis matrix The sensing matrix is constructed by multiplication. Then based on the sensor matrix and frequency domain signals Establish the following compressed sensing model: ； Then, the basis pursuit noise reduction algorithm is used to solve the compressed sensing model to obtain the wavenumber domain spectrum of the complete leakage sound field. .
4. The spacecraft structural leak location method based on a capacitive microelectromechanical ultrasonic array according to claim 1, characterized in that: In step 4), the method for identifying the leakage direction based on the aforementioned wavenumber domain spectrum and obtaining the propagation direction axis of the leakage acoustic signal is as follows: by extracting the wavenumber domain spectrum. The point of maximum energy in the signal can be used to determine the direction of the corresponding wavenumber vector, and thus the propagation direction axis of the leakage sound signal can be obtained. .