Bridge displacement monitoring method and system based on phase information

Abstract

The invention provides a bridge displacement monitoring method and system based on phase information, and the method comprises the steps: carrying out the pyramid decomposition of multi-scale direction decomposition on processed video data, carrying out the filtering of a phase spectrum in a time domain, extracting an interested frequency band, and amplifying the phase spectrum; obtaining a structure displacement signal according to the amplification signal and the center phase, and generating a pixel point displacement signal based on the structure displacement signal; establishing a physical coordinate system in each frame of image in the video data, converting the physical coordinate system into a modal coordinate system, mapping the pixel point displacement signal on the modal coordinate system, and taking the pixel point displacement signal on the modal coordinate system as an input signal; and constructing a modal analysis model, and identifying the modal response of the input signal based on the modal analysis model to obtain bridge monitoring information. According to the invention, the displacement information of the bridge can be accurately and comprehensively monitored.

Description

Technical Field

[0001] This invention relates to the field of bridge monitoring technology, and in particular to a bridge displacement monitoring method and system based on phase information. Background Technology

[0002] Bridges are vital facilities connecting cities and villages, and are also crucial infrastructure for modern transportation. Generally, a bridge refers to a structure erected across rivers, lakes, or seas to allow vehicles and pedestrians to pass smoothly. However, to adapt to the rapidly developing modern transportation industry, the term "bridge" has also come to refer to structures built across mountains, challenging geological conditions, or to meet other transportation needs, making travel more convenient.

[0003] Structural health monitoring is a technology that uses various types of sensors deployed on a structure to acquire data on the structural environment and loads, as well as overall and local responses, and analyzes this data to determine the structural safety status. Overall structural deformation is a crucial monitoring component. Structural displacement is primarily caused by loads, temperature changes, support settlement, and changes in structural material properties over time. Commonly used structural displacement measurement techniques mainly involve acceleration integration and direct GPS measurement. These methods are mostly traditional contact-based methods, generally requiring pre-installation of instruments on the surface (or inside) of the structure being measured. This preparation is cumbersome and easily affected by environmental conditions. These methods also involve single measurement points, complex setup requirements, increased structural burden, high workload, and high costs, failing to meet the requirements for real-time, multi-point dynamic monitoring of structural deformation.

[0004] In existing technologies, the preparation work for contact monitoring of bridges is cumbersome and the monitoring results are easily affected by environmental conditions. Non-contact monitoring mostly uses lasers for monitoring, which is not only costly, but also has a relatively limited monitoring method and measuring points. Radar monitoring can also affect the monitoring accuracy due to the measurement distance. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide a bridge displacement monitoring method and system based on phase information to overcome the shortcomings of the prior art.

[0006] In a first aspect, the present invention provides a bridge displacement monitoring method based on phase information, the method comprising: Real-time acquisition of video data from the bridge, and processing of the video data to obtain processed video data; The processed video data is decomposed into a pyramid using multi-scale directional decomposition to obtain the phase spectrum and amplitude spectrum. The phase spectrum is then filtered in the time domain to extract the frequency band of interest, and the amplitude spectrum is amplified. The frequency band of interest is amplified based on the structural displacement and the amplified amplitude spectrum to obtain an amplified signal. The structural displacement signal is obtained based on the amplified signal and the center phase, and a pixel displacement signal is generated based on the structural displacement signal. A physical coordinate system is established for each frame of the video data, the physical coordinate system is transformed into a modal coordinate system, and the pixel displacement signal is mapped onto the modal coordinate system so as to use the pixel displacement signal on the modal coordinate system as an input signal. A modal analysis model is constructed, and the modal response of the input signal is identified based on the modal analysis model to obtain bridge monitoring information.

[0007] Compared with the prior art, the beneficial effects of the present invention are: by performing pyramid decomposition on the video data of the bridge in multiple scale directions, the phase spectrum and amplitude spectrum of the bridge can be obtained, and a more comprehensive phase information of the bridge can be obtained. By amplifying the amplitude spectrum and generating pixel displacement signals from the obtained structural displacement signals, the modal analysis model can identify the pixel displacement signals, thereby obtaining the displacement information of the bridge and other information, and thus enabling accurate and comprehensive monitoring of the displacement information of the bridge.

[0008] Furthermore, the step of real-time acquisition of video data from the bridge and processing the video data includes: Acquire bridge video data captured in real time by high-definition network cameras; The bridge video data is subjected to noise reduction processing. An adaptive spatiotemporal filtering algorithm is used to eliminate interference in the bridge video data, and histogram equalization is used to further process the bridge video data.

[0009] Furthermore, the expression for the pyramid decomposition is: ; In the formula, Indicates the first image of the output image Layer in coordinates Pixel value at that location, Represents the image pyramid function. This represents the processed video data. , These represent the row coordinates and column coordinates of an image in the processed video data, respectively. , These represent the row offset and column offset, respectively. This represents the weight kernel function.

[0010] Furthermore, the step of obtaining the structural displacement signal based on the amplified signal and the center phase, and generating the pixel displacement signal based on the structural displacement signal, includes: A fixed reference frame is used, and the center phase is obtained based on the fixed reference frame and the sequence of video data; The relationship between the true displacement and the multiple of the central phase is obtained to acquire the structural displacement information contained in the central phase on a spatial scale. Based on this structural displacement information and the amplified signal, a structural displacement signal is obtained, wherein the expression for the structural displacement is: ; In the formula, Indicates structural displacement. This represents the ratio of the true displacement to the central phase. This represents a constant phase offset. A pixel displacement signal is generated based on the pixel points in the structural displacement signal and the center phase.

[0011] Furthermore, the expression for amplifying the amplitude spectrum is: ; In the formula, This represents the complex signal of the amplified amplitude spectrum. Indicates spatial location, Indicates time, Represents angular frequency. The base of the natural logarithm. Represents the imaginary unit. Represents the scaling constant. This represents a constant phase offset. Indicates at angular frequency Spatial location and time The real-value amplitude of the signal, Center frequency, This represents a time-dependent displacement.

[0012] Furthermore, the step of establishing a physical coordinate system for each frame of the video data, transforming the physical coordinate system into a modal coordinate system, and mapping the pixel displacement signal onto the modal coordinate system to use the pixel displacement signal on the modal coordinate system as an input signal includes: Each frame of the video data is calibrated based on its position, and a two-dimensional physical coordinate system is established. Based on the finite element model or experimental modal analysis results of the bridge, the modal basis vectors of the dominant vibration modes are selected, and the two-dimensional physical coordinate system is projected onto the modal coordinate system through the coordinate transformation matrix. The pixel displacement fields of consecutive frames of the video data are extracted, the displacement fields are transformed into the two-dimensional physical coordinate system, and the physical displacements are mapped onto the modal coordinate system through modal projection as input signals.

[0013] Furthermore, the step of constructing a modal analysis model and identifying the modal response of the input signal based on the modal analysis model includes: A modal analysis model is established based on the motion equations of the pixel displacement signals in the physical coordinate system. The modal analysis model is used to identify pixel displacement information in the input signal.

[0014] Secondly, the present invention also provides a bridge displacement monitoring system based on phase information, the system comprising: The acquisition and processing module is used to acquire video data of the bridge in real time and process the video data to obtain processed video data. The decomposition and extraction module is used to decompose the processed video data through a pyramid decomposition with multi-scale directional decomposition to obtain the phase spectrum and amplitude spectrum, and to extract the frequency band of interest by time-domain filtering of the phase spectrum and amplify the amplitude spectrum. The amplification generation module is used to amplify the frequency band of interest based on the structural displacement and combined with the amplified amplitude spectrum to obtain an amplified signal, obtain a structural displacement signal based on the amplified signal and the center phase, and generate a pixel displacement signal based on the structural displacement signal. A mapping module is established to establish a physical coordinate system for each frame of the video data, transform the physical coordinate system into a modal coordinate system, and map the pixel displacement signal onto the modal coordinate system so as to use the pixel displacement signal on the modal coordinate system as an input signal. A recognition module is constructed to build a modal analysis model and identify the modal response of the input signal based on the modal analysis model in order to obtain bridge monitoring information.

[0015] Thirdly, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-described bridge displacement monitoring method based on phase information.

[0016] Fourthly, the present invention also provides a storage medium storing a computer program thereon, which, when executed by a processor, implements the above-described bridge displacement monitoring method based on phase information. Attached Figure Description

[0017] Figure 1This is a flowchart of the bridge displacement monitoring method based on phase information in the first embodiment of the present invention; Figure 2 This is a structural block diagram of the bridge displacement monitoring system based on phase information in the second embodiment of the present invention; Figure 3 This is a structural block diagram of the electronic device in the third embodiment of the present invention.

[0018] Explanation of key component symbols: 10. Acquisition and Processing Module; 20. Decomposition and Extraction Module; 30. Magnification and Generation Module; 40. Mapping Establishment Module; 50. Recognition Construction Module; 60. Bus; 61. Processor; 62. Memory; 63. Communication interface.

[0019] The following detailed description, in conjunction with the accompanying drawings, will further illustrate the present invention. Detailed Implementation

[0020] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0021] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0023] Example 1 Please see Figure 1 The figure shows a bridge displacement monitoring method based on phase information in the first embodiment of the present invention, the method comprising steps S1 to S5: S1, real-time acquisition of video data of the bridge, and processing of the video data to obtain processed video data; Specifically, step S1 includes steps S11 to S12: S11, acquire bridge video data collected in real time by high-definition network cameras; S12, the bridge video data is subjected to noise reduction processing. An adaptive spatiotemporal filtering algorithm is used to eliminate interference in the bridge video data, and the bridge video data is further processed by histogram equalization. It is understandable that adaptive spatiotemporal filtering algorithms are used to filter the images in the bridge video data to eliminate interference from weather conditions such as rain and fog, and histogram equalization is used to optimize the bridge video data to further eliminate interference in the video images.

[0024] S2, the processed video data is decomposed into a pyramid using multi-scale directional decomposition to obtain the phase spectrum and amplitude spectrum, and the phase spectrum is filtered in the time domain to extract the frequency band of interest, and the amplitude spectrum is amplified; Understandably, pyramid decomposition, through its manipulated localized non-aliased subbands, is used to extract the amplitude and local phase of decomposed video data, thereby obtaining the phase spectrum and amplitude spectrum. Furthermore, multi-scale image decomposition subsequently finds the optimal scale for structure, and since the pyramid is manipulated, the frequency band of interest is extracted from the phase spectrum, and the amplitude spectrum is amplified. In this embodiment, the expression for pyramid decomposition is: ; In the formula, Indicates the first image of the output image Layer in coordinates Pixel value at that location, Represents the image pyramid function. This represents the processed video data. , These represent the row coordinates and column coordinates of an image in the processed video data, respectively. , These represent the row offset and column offset, respectively. Represents the weight kernel function; The expression for amplifying the amplitude spectrum is: ; In the formula, This represents the complex signal of the amplified amplitude spectrum. Indicates spatial location, Indicates time, Represents angular frequency. The base of the natural logarithm. Represents the imaginary unit. Represents the scaling constant. This represents a constant phase offset. Indicates at angular frequency Spatial location and time The real-value amplitude of the signal, Center frequency, This represents a time-dependent displacement.

[0025] S3, the frequency band of interest is amplified based on the structural displacement and combined with the amplified amplitude spectrum to obtain an amplified signal, the structural displacement signal is obtained according to the amplified signal and the center phase, and a pixel displacement signal is generated based on the structural displacement signal; Specifically, step S3 includes steps S31 to S33: S31, fix the reference frame, and obtain the center phase based on the fixed reference frame and the sequence of video data; S32, Obtain the multiple relationship between the true displacement and the center phase to obtain the structural displacement information contained in the center phase on a spatial scale, and obtain the structural displacement signal based on the structural displacement information and the amplified signal, wherein the expression for the structural displacement is: ; In the formula, Indicates structural displacement. This represents the ratio of the true displacement to the central phase. This represents a constant phase offset. S33, Based on the pixels in the structural displacement signal and the center phase, a pixel displacement signal is generated; It is understandable that by fixing a certain reference frame and calculating the center phase of the video data sequence after temporal filtering, the structural displacement and the center phase in multiple scale directions are measured by displacement measurement methods to obtain the ratio of displacement to center phase. If the center phase in the spatial scale contains structural displacement information, then the true structural displacement and center phase are in a multiple relationship. After applying the complex-directional manipulatory pyramid to the video frame, the center phase contains structural vibration displacement information at each spatial scale. Then, based on the structural displacement information and the amplified signal, the structural displacement signal is obtained, and the pixel displacement signal is generated by using the pixels in the structural displacement signal and the center phase.

[0026] S4, establish a physical coordinate system for each frame of the video data, transform the physical coordinate system into a modal coordinate system, and map the pixel displacement signal onto the modal coordinate system so as to use the pixel displacement signal on the modal coordinate system as an input signal; Specifically, step S4 includes steps S41 to S43: S41, each frame of the video data is calibrated based on its position and a two-dimensional physical coordinate system is established; It is understandable that for each frame of video data, a two-dimensional physical coordinate system is established based on a preset position calibration device, such as a checkerboard calibration board, a laser reference point, or a physical reference object of known size, and the origin and axial unit of the coordinate system are defined. S42, based on the finite element model or experimental modal analysis results of the bridge, select the modal basis vectors of the dominant vibration modes, and project the two-dimensional physical coordinate system onto the modal coordinate system through the coordinate transformation matrix; S43, extract the pixel displacement field of the continuous frame images of the video data, transform the displacement field to the two-dimensional physical coordinate system, and map the physical displacement to the modal coordinate system through modal projection as an input signal; Understandably, based on the dynamic characteristics of the target bridge, the modal basis vectors of the dominant vibration modes are selected through the finite element model of the bridge or the results of experimental modal analysis. The displacement vectors in the physical coordinate system are then projected to the modal coordinate system through a coordinate transformation matrix to achieve the purpose of modal coordinate transformation. In this embodiment, by extracting the displacement field of pixels between consecutive frames, the optical flow method can be used to transform the displacement field to a two-dimensional physical coordinate system. The physical displacement is then mapped to the modal coordinates through modal projection.

[0027] S5, construct a modal analysis model, and identify the modal response of the input signal based on the modal analysis model to obtain bridge monitoring information; Specifically, step S5 includes steps S51 to S52: S51, establish a modal analysis model based on the motion equation of the pixel displacement signal in the physical coordinate system; S52, Identify pixel displacement information in the input signal based on the modal analysis model; It is understandable that the finite element method is used to discretize the structure, and a modal analysis model is established by using the motion equations of pixel displacement signals in the physical coordinate system. The modal analysis model uses random subspace identification and dynamic modal parameter tracking to effectively identify pixel displacement information in the input signal, thereby enabling the bridge displacement to be judged based on the pixel displacement information, and thus enabling effective monitoring of the bridge.

[0028] In summary, the bridge displacement monitoring method based on phase information in the above embodiments of the present invention can obtain the phase spectrum and amplitude spectrum of the bridge by performing multi-scale directional pyramid decomposition on the bridge's video data, and can obtain relatively comprehensive phase information of the bridge. By amplifying the amplitude spectrum and generating pixel displacement signals from the obtained structural displacement signals, the modal analysis model can identify the pixel displacement signals, thereby obtaining the bridge's displacement information and other information, and thus enabling accurate and comprehensive monitoring of the bridge's displacement information.

[0029] Example 2 The second embodiment of the present invention also provides a bridge displacement monitoring system based on phase information. Please refer to [link / reference]. Figure 2 The figure shows a bridge displacement monitoring system based on phase information according to a second embodiment of the present invention. The system includes: The acquisition and processing module 10 is used to acquire video data of the bridge in real time and process the video data to obtain processed video data. The decomposition and extraction module 20 is used to perform pyramid decomposition on the processed video data using multi-scale directional decomposition to obtain the phase spectrum and amplitude spectrum, and to extract the frequency band of interest from the phase spectrum by temporal filtering, and to amplify the amplitude spectrum. The expression for the pyramid decomposition is: ; In the formula, Indicates the first image of the output image Layer in coordinates Pixel value at that location, Represents the image pyramid function. This represents the processed video data. , These represent the row coordinates and column coordinates of an image in the processed video data, respectively. , These represent the row offset and column offset, respectively. Represents the weight kernel function; The expression for amplifying the amplitude spectrum is: ; In the formula, This represents the complex signal of the amplified amplitude spectrum. Indicates spatial location, Indicates time, Represents angular frequency. The base of the natural logarithm. Represents the imaginary unit. Represents the scaling constant. This represents a constant phase offset. Indicates at angular frequency Spatial location and time The real-value amplitude of the signal, Center frequency, Indicates time-dependent displacement; The amplification generation module 30 is used to amplify the frequency band of interest based on the structural displacement and combined with the amplified amplitude spectrum to obtain an amplified signal, obtain a structural displacement signal based on the amplified signal and the center phase, and generate a pixel displacement signal based on the structural displacement signal. The mapping module 40 is used to establish a physical coordinate system for each frame of the video data, transform the physical coordinate system into a modal coordinate system, and map the pixel displacement signal onto the modal coordinate system so as to use the pixel displacement signal on the modal coordinate system as an input signal. A recognition module 50 is constructed to build a modal analysis model and identify the modal response of the input signal based on the modal analysis model in order to obtain bridge monitoring information.

[0030] In some optional embodiments, the acquisition and processing module 10 includes: The acquisition unit is used to acquire bridge video data collected in real time by high-definition network cameras; The processing unit is used to perform noise reduction processing on the bridge video data, using an adaptive spatiotemporal filtering algorithm to eliminate interference in the bridge video data, and further processing the bridge video data through histogram equalization.

[0031] In some alternative embodiments, the amplification generation module 30 includes: A fixed unit is used to fix a reference frame and obtain the center phase based on the fixed reference frame and the sequence of video data; An amplification unit is used to acquire the multiple relationship between the true displacement and the central phase, so as to obtain the structural displacement information contained in the central phase on a spatial scale, and to obtain the structural displacement signal based on the structural displacement information and the amplified signal, wherein the expression of the structural displacement is: ; In the formula, Indicates structural displacement. This represents the ratio of the true displacement to the central phase. This represents a constant phase offset. The generation unit is used to generate a pixel displacement signal based on the pixel points in the structural displacement signal and the center phase.

[0032] In some alternative embodiments, the mapping establishment module 40 includes: The calibration establishment unit is used to calibrate each frame of the video data based on the set position and establish a two-dimensional physical coordinate system; Projection elements are selected to select the modal basis vectors of the dominant vibration modes based on the finite element model or experimental modal analysis results of the bridge, and the two-dimensional physical coordinate system is projected onto the modal coordinate system through the coordinate transformation matrix; The extraction and transformation unit is used to extract the pixel displacement field of consecutive frame images of the video data, transform the displacement field to the two-dimensional physical coordinate system, and map the physical displacement onto the modal coordinate system through modal projection as an input signal.

[0033] In some alternative embodiments, the construction identification module 50 includes: A modeling unit is established based on the motion equations of the pixel displacement signals in the physical coordinate system to establish a modal analysis model. The identification unit is used to identify pixel displacement information in the input signal based on the modal analysis model.

[0034] The functions or operation steps implemented by the above modules and units are largely the same as those in the above method embodiments, and will not be repeated here.

[0035] The bridge displacement monitoring system based on phase information provided in this embodiment of the invention has the same implementation principle and technical effect as the aforementioned method embodiment. For the sake of brevity, any parts not mentioned in the system embodiment can be referred to the corresponding content in the aforementioned method embodiment.

[0036] Example 3 The third embodiment of the present invention also proposes an electronic device, please refer to [link / reference]. Figure 3 The image shows an electronic device according to a third embodiment of the present invention.

[0037] The electronic device may include a processor 61 and a memory 62 storing computer program instructions.

[0038] Specifically, the processor 61 may include a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits that can be configured to implement the present application.

[0039] The memory 62 may include a large-capacity storage device for data or instructions. For example, and not limitingly, the memory 62 may include a hard disk drive (HDD), a floppy disk drive, a solid-state drive (SSD), flash memory, an optical disk drive, a magneto-optical disk drive, magnetic tape, or a Universal Serial Bus (USB) drive, or a combination of two or more of these. Where appropriate, the memory 62 may include removable or non-removable (or fixed) media. Where appropriate, the memory 62 may be internal or external to a data processing device. In a particular embodiment, the memory 62 is non-volatile memory. In a particular embodiment, the memory 62 includes read-only memory (ROM) and random access memory (RAM). Where appropriate, the ROM may be a mask-programmed ROM, a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), an electrically alterable read-only memory (EAROM), or flash memory, or a combination of two or more of these. Where appropriate, the RAM can be Static Random-Access Memory (SRAM) or Dynamic Random-Access Memory (DRAM). DRAM can be Fast Page Mode Dynamic Random-Access Memory (FPMDRAM), Extended Data Out Dynamic Random-Access Memory (EDODRAM), Synchronous Dynamic Random-Access Memory (SDRAM), etc.

[0040] The memory 62 can be used to store or cache various data files that need to be processed and / or communicated, as well as possible computer program instructions executed by the processor 61.

[0041] The processor 61 reads and executes the computer program instructions stored in the memory 62 to implement the bridge displacement monitoring method based on phase information described in Embodiment 1.

[0042] In some embodiments, the electronic device may further include a communication interface 63 and a bus 60. For example, Figure 3 As shown, the processor 61, memory 62, and communication interface 63 are connected through bus 60 and complete communication with each other.

[0043] The communication interface 63 is used to enable communication between the various modules, devices, units, and / or equipment in this application. The communication interface 63 can also enable data communication with other components such as external devices, image / data acquisition devices, databases, external storage, and image / data processing workstations.

[0044] Bus 60 includes hardware, software, or both, that couples components of a device together. Bus 60 includes, but is not limited to, at least one of the following: data bus, address bus, control bus, expansion bus, and local bus. For example, and not as a limitation, bus 60 may include an Accelerated Graphics Port (AGP) or other graphics bus, an Extended Industry Standard Architecture (EISA) bus, a Front Side Bus (FSB), a Hyper Transport (HT) interconnect, an Industry Standard Architecture (ISA) bus, an InfiniBand interconnect, a Low Pin Count (LPC) bus, a memory bus, a Micro Channel Architecture (MCA) bus, a Peripheral Component Interconnect (PCI) bus, a PCI-Express (PCI-X) bus, a Serial Advanced Technology Attachment (SATA) bus, a Video Electronics Standards Association Local Bus (VLB) bus, or other suitable buses, or a combination of two or more of these. Where appropriate, bus 60 may include one or more buses. Although this application describes and illustrates a specific bus, this application considers any suitable bus or interconnection.

[0045] The electronic device can acquire a bridge displacement monitoring system based on phase information and execute the bridge displacement monitoring method based on phase information in this embodiment.

[0046] Furthermore, in conjunction with the bridge displacement monitoring method based on phase information in Embodiment 1 above, this application can provide a storage medium for implementation. This storage medium stores computer program instructions; when these computer program instructions are executed by a processor, they implement the bridge displacement monitoring method based on phase information in Embodiment 1 above.

[0047] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0048] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A bridge displacement monitoring method based on phase information, characterized in that, The method includes: Real-time acquisition of video data from the bridge, and processing of the video data to obtain processed video data; The processed video data is decomposed into a pyramid using multi-scale directional decomposition to obtain the phase spectrum and amplitude spectrum. The phase spectrum is then filtered in the time domain to extract the frequency band of interest, and the amplitude spectrum is amplified. The frequency band of interest is amplified based on the structural displacement and the amplified amplitude spectrum to obtain an amplified signal. The structural displacement signal is obtained based on the amplified signal and the center phase, and a pixel displacement signal is generated based on the structural displacement signal. A physical coordinate system is established for each frame of the video data, the physical coordinate system is transformed into a modal coordinate system, and the pixel displacement signal is mapped onto the modal coordinate system so as to use the pixel displacement signal on the modal coordinate system as an input signal. A modal analysis model is constructed, and the modal response of the input signal is identified based on the modal analysis model to obtain bridge monitoring information.

2. The bridge displacement monitoring method based on phase information according to claim 1, characterized in that, The steps of acquiring real-time video data of the bridge and processing the video data include: Acquire bridge video data captured in real time by high-definition network cameras; The bridge video data is subjected to noise reduction processing. An adaptive spatiotemporal filtering algorithm is used to eliminate interference in the bridge video data, and histogram equalization is used to further process the bridge video data.

3. The bridge displacement monitoring method based on phase information according to claim 1, characterized in that, The expression for the pyramid decomposition is: ； In the formula, Indicates the first image of the output image Layer in coordinates Pixel value at that location, Represents the image pyramid function. This represents the processed video data. , These represent the row coordinates and column coordinates of an image in the processed video data, respectively. , These represent the row offset and column offset, respectively. This represents the weight kernel function.

4. The bridge displacement monitoring method based on phase information according to claim 1, characterized in that, The step of obtaining the structural displacement signal based on the amplified signal and the center phase, and generating the pixel displacement signal based on the structural displacement signal includes: A fixed reference frame is used, and the center phase is obtained based on the fixed reference frame and the sequence of video data; The relationship between the true displacement and the multiple of the central phase is obtained to acquire the structural displacement information contained in the central phase on a spatial scale. Based on this structural displacement information and the amplified signal, a structural displacement signal is obtained, wherein the expression for the structural displacement is: ； In the formula, Indicates structural displacement. This represents the ratio of the true displacement to the central phase. This represents a constant phase offset. A pixel displacement signal is generated based on the pixel points in the structural displacement signal and the center phase.

5. The bridge displacement monitoring method based on phase information according to claim 1, characterized in that, The expression for amplifying the amplitude spectrum is: ； In the formula, This represents the complex signal of the amplified amplitude spectrum. Indicates spatial location, Indicates time, Represents angular frequency. The base of the natural logarithm. Represents the imaginary unit. Represents the scaling constant. This represents a constant phase offset. Indicates at angular frequency Spatial location and time The real-value amplitude of the signal, Center frequency, This represents a time-dependent displacement.

6. The bridge displacement monitoring method based on phase information according to claim 1, characterized in that, The steps of establishing a physical coordinate system for each frame of the video data, transforming the physical coordinate system into a modal coordinate system, and mapping the pixel displacement signal onto the modal coordinate system to use the pixel displacement signal on the modal coordinate system as an input signal include: Each frame of the video data is calibrated based on its position, and a two-dimensional physical coordinate system is established. Based on the finite element model or experimental modal analysis results of the bridge, the modal basis vectors of the dominant vibration modes are selected, and the two-dimensional physical coordinate system is projected onto the modal coordinate system through the coordinate transformation matrix. The pixel displacement fields of consecutive frames of the video data are extracted, the displacement fields are transformed into the two-dimensional physical coordinate system, and the physical displacements are mapped onto the modal coordinate system through modal projection as input signals.

7. The bridge displacement monitoring method based on phase information according to claim 1, characterized in that, The steps of constructing a modal analysis model and identifying the modal response of the input signal based on the modal analysis model include: A modal analysis model is established based on the motion equations of the pixel displacement signals in the physical coordinate system. The modal analysis model is used to identify pixel displacement information in the input signal.

8. A bridge displacement monitoring system based on phase information, characterized in that, The system includes: The acquisition and processing module is used to acquire video data of the bridge in real time and process the video data to obtain processed video data. The decomposition and extraction module is used to decompose the processed video data through a pyramid decomposition with multi-scale directional decomposition to obtain the phase spectrum and amplitude spectrum, and to extract the frequency band of interest by time-domain filtering of the phase spectrum and amplify the amplitude spectrum. The amplification generation module is used to amplify the frequency band of interest based on the structural displacement and combined with the amplified amplitude spectrum to obtain an amplified signal, obtain a structural displacement signal based on the amplified signal and the center phase, and generate a pixel displacement signal based on the structural displacement signal. A mapping module is established to establish a physical coordinate system for each frame of the video data, transform the physical coordinate system into a modal coordinate system, and map the pixel displacement signal onto the modal coordinate system so as to use the pixel displacement signal on the modal coordinate system as an input signal. A recognition module is constructed to build a modal analysis model and identify the modal response of the input signal based on the modal analysis model in order to obtain bridge monitoring information.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the bridge displacement monitoring method based on phase information as described in any one of claims 1 to 7.

10. A storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the bridge displacement monitoring method based on phase information as described in any one of claims 1 to 7.

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