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: obtaining a two-dimensional grating image of a bridge, and carrying out the preprocessing of the two-dimensional grating image, so as to obtain a one-dimensional grating image; performing sampling and interpolation processing on the one-dimensional grating image to obtain a plurality of moire fringes; determining a phase solving equation based on the plurality of moire fringes; solving the phase solving equation to obtain a Moire phase; the bridge displacement is determined based on the Moire phase, the final bridge displacement is determined through the Moire phase, the infinitesimal displacement change of the bridge can be effectively recognized, and the accuracy and precision of the determined bridge displacement are high.

Description

Technical Field

[0001] The present invention belongs to the technical field of bridge monitoring, and in particular relates to a bridge displacement monitoring method and system based on phase information. Background Art

[0002] Bridge displacement refers to the structural deformation of the bridge under load, including vertical displacement, horizontal displacement and torsional displacement. Excessive displacement will cause the bridge structure to become unstable and affect driving safety.

[0003] Traditional bridge displacement monitoring methods usually obtain images of the bridge within a preset time period and determine the bridge displacement based on the differences between the images. However, there are problems with displacement monitoring accuracy being low and the inability to effectively identify small displacement changes of the bridge. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a bridge displacement monitoring method and system based on phase information, which are used to solve the technical problems in the prior art.

[0005] On the one hand, the present invention provides the following technical solution, a bridge displacement monitoring method based on phase information, comprising: Acquire a two-dimensional grating image of the bridge, and pre-process the two-dimensional grating image to obtain a one-dimensional grating image; Sampling and interpolating the one-dimensional grating image to obtain a plurality of moiré fringes; Determine the phase and solve the equation based on the moiré fringes; Solving the phase solution equation to obtain a moiré phase; The bridge displacement is determined based on the moiré phase.

[0006] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention first obtains a two-dimensional grating image of the bridge, and pre-processes the two-dimensional grating image to obtain a one-dimensional grating image; then samples and interpolates the one-dimensional grating image to obtain a number of moiré fringes; then determines a phase solution equation based on the number of moiré fringes; then solves the phase solution equation to obtain a moiré phase; finally, determines the bridge displacement based on the moiré phase. The present invention determines the final bridge displacement through the moiré phase, can effectively identify small displacement changes of the bridge, and the determined bridge displacement has high accuracy and precision.

[0007] Preferably, the step of preprocessing the two-dimensional image to obtain a one-dimensional grating image is specifically: The two-dimensional grating image is subjected to low-pass filtering or mean filtering to obtain a one-dimensional grating image.

[0008] Preferably, the step of sampling and interpolating the one-dimensional grating image to obtain a plurality of moiré fringes comprises: Set the sampling interval and a pre-sampled image, placing the first pixel of the first row in the one-dimensional raster image at the position of the first row and the first column in the pre-sampled image; Sequentially place the first row of the one-dimensional grating image The pixels are placed in the first row of the pre-sampled image. Department, is the number of samplings; The first row of the one-dimensional raster image The pixel points are placed in the first row of the pre-sampled image. The position of the column; Sequentially place the first row of the one-dimensional grating image The pixels are placed in the first row of the pre-sampled image. Department; The sampling process is repeated to obtain a number of sampling groups, and interpolation processing is performed on the number of sampling groups to obtain a number of moiré fringes.

[0009] Preferably, the step of determining the phase solution equation based on the plurality of moiré fringes comprises: Determine the coordinates of the moiré fringe Gray value : ; In the formula, , Represents the coordinates in a one-dimensional raster image The modulation gray value, the gray value of the background light intensity, Represents the coordinates in a one-dimensional raster image The phase of is the sampling interval, is the serial number of the moiré fringe; For the gray value Adjust the equation to get the phase solution equation: ; , , ; In the formula, , , denote the first, second, and third unknowns respectively; Define the error function : ; In the formula, Indicates Gray value of the moiré fringe; For the error function In , , Find the partial derivative to get the partial derivative equation: ; The partial derivative equation is transformed into a matrix to obtain a matrix equation: ; ; In the formula, To simplify the matrix; A phase solution equation is determined based on the matrix equation.

[0010] Preferably, the step of determining the phase solution equation based on the matrix equation comprises: The matrix equation is simplified by trigonometric functions to obtain a simplified matrix : ; Based on the simplified matrix Substitute into the matrix equation to determine the first unknown , the second unknown , the third unknown number : ; Based on the second unknown , the third unknown number Determine the first phase to be determined : ; The first phase to be determined is converted to obtain a second phase to be determined : ; Determine coordinates The second undetermined phase at , based on the second undetermined phase Determine the phase solving the equation: ; ; In the formula, represents the moiré phase to be solved, represents an integer, represents a discrete input, express The true phase of .

[0011] Preferably, the step of solving the phase solution equation to obtain the moiré phase includes: Calculate the discrete inputs in the phase solving equation : ; In the formula, represents the wrapping operator, , , , Respectively , , , The second undetermined phase at ; Based on discrete input Calculate the true phase : ; In the formula, represents discrete cosine transform, , Respectively , The maximum value of The real phase Substitute into the phase solution equation to obtain the moiré phase .

[0012] Preferably, the step of determining the bridge displacement based on the moiré phase comprises: Calculate the phase difference value based on the moiré phase : ; In the formula, , Respectively represent Frame, Frame 2D raster image The moiré phase at Based on the phase difference Calculating bridge displacements : ; In the formula, is the grating spacing.

[0013] In a second aspect, the present invention provides the following technical solution: a bridge displacement monitoring system based on phase information, the system comprising: A processing module, used for acquiring a two-dimensional grating image of the bridge, and preprocessing the two-dimensional grating image to obtain a one-dimensional grating image; A sampling module, used for sampling and interpolating the one-dimensional grating image to obtain a plurality of moiré fringes; An equation module, used for solving an equation based on a plurality of said moiré fringes to determine a phase; A solution module, used for solving the phase solution equation to obtain a moiré phase; A displacement module is used to determine the bridge displacement based on the moiré phase.

[0014] In a third aspect, the present invention provides the following technical solution: a computer comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the bridge displacement monitoring method based on phase information as described above when executing the computer program.

[0015] In a fourth aspect, the present invention provides the following technical solution: a storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the bridge displacement monitoring method based on phase information as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A flow chart of a bridge displacement monitoring method based on phase information provided in Embodiment 1 of the present invention; Figure 2 A structural block diagram of a bridge displacement monitoring system based on phase information provided in Embodiment 2 of the present invention; Figure 3 A schematic diagram of the hardware structure of a computer provided in another embodiment of the present invention.

[0018] The embodiments of the present invention will be further described below with reference to the accompanying drawings. DETAILED DESCRIPTION

[0019] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the embodiments of the present invention, and should not be construed as limiting the present invention.

[0020] In the description of the embodiments of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0022] In the embodiments of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0023] Embodiment 1 In the first embodiment of the present invention, Figure 1 As shown, a bridge displacement monitoring method based on phase information includes: S1, obtaining a two-dimensional grating image of the bridge, and preprocessing the two-dimensional grating image to obtain a one-dimensional grating image; Specifically, when formally acquiring the two-dimensional grating image, the grating needs to be printed out and pasted on the surface of the bridge, and then the image is acquired through the camera to obtain the two-dimensional grating image.

[0024] Wherein, step S1 is specifically as follows: Performing low-pass filtering or mean filtering on the two-dimensional grating image to obtain a one-dimensional grating image; Specifically, through low-pass filtering or mean filtering, the noise in the image can be removed and a one-dimensional grating image can be obtained.

[0025] S2, sampling and interpolating the one-dimensional grating image to obtain a plurality of moiré fringes; Wherein, the step S2 comprises: S21. Set sampling interval and a pre-sampled image, placing the first pixel point of the first row in the one-dimensional grating image at the position of the first row and the first column in the pre-sampled image.

[0026] S22, sequentially convert the first row of the one-dimensional grating image into The pixels are placed in the first row of the pre-sampled image. Department, is the number of samplings; Specifically, here It is calculated by dividing the total number of pixels in the first row of a one-dimensional raster image by the sampling interval and rounding down.

[0027] S23, the first row of the one-dimensional grating image The pixel points are placed in the first row of the pre-sampled image. Column position.

[0028] S24, sequentially convert the first row of the one-dimensional grating image into The pixels are placed in the first row of the pre-sampled image. Department; in, The value range is from 1 to between.

[0029] S25, repeating the sampling process to obtain a plurality of sampling groups, and performing interpolation processing on the plurality of sampling groups to obtain a plurality of moiré fringes; Specifically, after obtaining the sampling group, the pixel values ​​of the blank positions in the same row of the one-dimensional grating image are interpolated by linear interpolation, quadratic interpolation, cubic interpolation or spline interpolation to obtain a number of moiré fringes, and the number of moiré fringes is .

[0030] S3, determining a phase solution equation based on the plurality of moiré fringes; Wherein, the step S3 comprises: S31, determining the coordinates in the moiré fringes Gray value : ; In the formula, , Represents the coordinates in a one-dimensional raster image The modulation gray value, the gray value of the background light intensity, Represents the coordinates in a one-dimensional raster image The phase of is the sampling interval, is the ordinal number of the moiré fringe.

[0031] S32, the gray value Adjust the equation to get the phase solution equation: ; , , ; In the formula, , , represent the first, second, and third unknowns respectively.

[0032] S33. Define the error function : ; In the formula, Indicates Grayscale value of the moiré fringe.

[0033] S34, the error function In , , Find the partial derivative to get the partial derivative equation: .

[0034] S35, performing matrix transformation on the partial derivative equation to obtain a matrix equation: ; ; In the formula, To simplify the matrix.

[0035] S36, determining a phase solution equation based on the matrix equation; Wherein, the step S36 comprises: S361, simplifying the matrix equation by trigonometric functions to obtain a simplified matrix : ; Among them, since trigonometric functions are periodic, we can know that: ; The simplified matrix can be simplified according to the above relationship.

[0036] S362, based on the simplified matrix Substitute into the matrix equation to determine the first unknown , the second unknown , the third unknown number : .

[0037] S363, based on the second unknown , the third unknown number Determine the first phase to be determined : .

[0038] S364: convert the first phase to be determined to obtain a second phase to be determined : .

[0039] S365, determine coordinates The second undetermined phase at , based on the second undetermined phase Determine the phase solving the equation: ; ; In the formula, represents the moiré phase to be solved, represents an integer, represents a discrete input, express The true phase of .

[0040] S4, solving the phase solution equation to obtain a moiré phase; Wherein, the step S4 comprises: S41, calculating the discrete input in the phase solution equation : ; In the formula, represents the wrapping operator, , , , Respectively , , , The second undetermined phase at ; S42, based on discrete input Calculate the true phase : ; In the formula, represents discrete cosine transform, , Respectively , The maximum value of S43, the real phase Substitute into the phase solution equation to obtain the moiré phase .

[0041] S5. Determine bridge displacement based on the moiré phase.

[0042] Wherein, the step S5 comprises: S51, calculating the phase difference value based on the moiré phase : ; In the formula, , Respectively represent Frame, Frame 2D raster image The moiré phase at .

[0043] S52, based on phase difference Calculating bridge displacements : ; In the formula, is the grating spacing; Specifically, the bridge displacement here is the displacement of a certain coordinate, and in bridges, the cumulative displacement is generally concerned, so the bridge displacement can be By superimposing and repeating the above process, the continuous displacement field in the entire bridge area can be obtained.

[0044] The bridge displacement monitoring method based on phase information provided in the first embodiment of the present invention first obtains a two-dimensional grating image of the bridge, and pre-processes the two-dimensional grating image to obtain a one-dimensional grating image; then samples and interpolates the one-dimensional grating image to obtain a number of moiré fringes; then determines a phase solution equation based on the number of moiré fringes; then solves the phase solution equation to obtain a moiré phase; finally, determines the bridge displacement based on the moiré phase. The present invention determines the final bridge displacement through the moiré phase, can effectively identify small displacement changes of the bridge, and the determined bridge displacement has high accuracy and precision.

[0045] Embodiment 2 like Figure 2 As shown, in the second embodiment of the present invention, a bridge displacement monitoring system based on phase information is provided, and the system includes: Processing module 1, used for acquiring a two-dimensional grating image of the bridge, and preprocessing the two-dimensional grating image to obtain a one-dimensional grating image; A sampling module 2, used for sampling and interpolating the one-dimensional grating image to obtain a plurality of moiré fringes; Equation module 3, used for solving equations based on the phase determination of the plurality of moiré fringes; A solution module 4 is used to solve the phase solution equation to obtain a moiré phase; A displacement module 5, for determining a bridge displacement based on the moiré phase; The processing module 1 is specifically used for: The two-dimensional grating image is subjected to low-pass filtering or mean filtering to obtain a one-dimensional grating image.

[0046] The sampling module 2 comprises: The first sampling submodule is used to set the sampling interval and a pre-sampled image, placing the first pixel of the first row in the one-dimensional raster image at the position of the first row and the first column in the pre-sampled image; The second sampling submodule is used to sequentially sample the first row of the one-dimensional raster image. The pixels are placed in the first row of the pre-sampled image. Department, is the number of samplings; The third sampling submodule is used to convert the first row of the one-dimensional raster image into The pixel points are placed in the first row of the pre-sampled image. The position of the column; The fourth sampling submodule is used to sequentially The pixels are placed in the first row of the pre-sampled image. Department; The interpolation submodule is used to repeat the sampling process to obtain a number of sampling groups, and perform interpolation processing on the number of sampling groups to obtain a number of moiré fringes.

[0047] The equation module 3 includes: The first calculation submodule is used to determine the coordinates in the moiré fringe Gray value : ; In the formula, , Represents the coordinates in a one-dimensional raster image The modulation gray value, the gray value of the background light intensity, Represents the coordinates in a one-dimensional raster image The phase of is the sampling interval, is the serial number of the moiré fringe; The second calculation submodule is used to calculate the gray value Adjust the equation to get the phase solution equation: ; , , ; In the formula, , , denote the first, second, and third unknowns respectively; The third calculation submodule is used to define the error function : ; In the formula, Indicates Gray value of the moiré fringe; The fourth calculation submodule is used to calculate the error function In , , Find the partial derivative to get the partial derivative equation: ; The fifth computing submodule is used to perform matrix transformation on the partial derivative equation to obtain a matrix equation: ; ; In the formula, To simplify the matrix; The sixth calculation submodule is used to determine the phase solution equation based on the matrix equation.

[0048] The sixth calculation submodule includes: The first calculation unit is used to simplify the matrix equation by trigonometric function to obtain a simplified matrix : ; A second computing unit is used for calculating the simplified matrix based on the simplified matrix Substitute into the matrix equation to determine the first unknown , the second unknown , the third unknown number : ; The third calculation unit is used to calculate the second unknown number based on the , the third unknown number Determine the first phase to be determined : ; A fourth calculation unit, configured to convert the first phase to be determined to obtain a second phase to be determined : ; The fifth calculation unit is used to determine the coordinates The second undetermined phase at , based on the second undetermined phase Determine the phase solving the equation: ; ; In the formula, represents the moiré phase to be solved, represents an integer, represents a discrete input, express The true phase of .

[0049] The solution module 4 comprises: Input submodule, used to calculate the discrete inputs in the phase solution equation : ; In the formula, represents the wrapping operator, , , , Respectively , , , The second undetermined phase at ; Phase submodule for discrete input Calculate the true phase : ; In the formula, represents discrete cosine transform, , Respectively , The maximum value of The solving submodule is used to convert the true phase Substitute into the phase solution equation to obtain the moiré phase .

[0050] The displacement module 5 comprises: A difference calculation submodule, used to calculate the phase difference based on the moiré phase : ; In the formula, , Respectively represent Frame, Frame 2D raster image The moiré phase at The displacement calculation submodule is used to calculate the displacement based on the phase difference value. Calculating bridge displacements : ; In the formula, is the grating spacing.

[0051] In some other embodiments of the present invention, the embodiments of the present invention provide the following technical solution: a computer, comprising a memory 102, a processor 101, and a computer program stored in the memory 102 and executable on the processor 101; when the processor 101 executes the computer program, the bridge displacement monitoring method based on phase information as described above is implemented.

[0052] Specifically, the processor 101 may include a central processing unit (CPU), or an application specific integrated circuit (ASIC), or may be configured to implement one or more integrated circuits of the embodiment of the present invention.

[0053] Among them, the memory 102 may include a large-capacity memory for data or instructions. By way of example and not limitation, the memory 102 may include a hard disk drive (HDD), a floppy disk drive, a solid state drive (SSD), a flash memory, an optical disk, a magneto-optical disk, a magnetic tape, or a universal serial bus (USB) drive, or a combination of two or more of these. Where appropriate, the memory 102 may include a removable or non-removable (or fixed) medium. Where appropriate, the memory 102 may be inside or outside the data processing device. In a specific embodiment, the memory 102 is a non-volatile memory. In a specific embodiment, the memory 102 includes a read-only memory (ROM) and a random access memory (RAM). Where appropriate, the ROM may be a mask-programmed ROM, a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), an electrically alterable ROM (EAROM) or a flash memory (FLASH), or a combination of two or more of these. Under appropriate circumstances, the RAM can be a static random access memory (SRAM) or a dynamic random access memory (DRAM), wherein the DRAM can be a fast page mode dynamic random access memory (FPMDRAM), an extended data output dynamic random access memory (EDODRAM), a synchronous dynamic random access memory (SDRAM), etc.

[0054] The memory 102 may be used to store or cache various data files that need to be processed and / or used for communication, as well as possible computer program instructions executed by the processor 101 .

[0055] The processor 101 implements the above-mentioned bridge displacement monitoring method based on phase information by reading and executing the computer program instructions stored in the memory 102 .

[0056] In some embodiments, the computer may further include a communication interface 103 and a bus 100. Figure 3 As shown, the processor 101, the memory 102, and the communication interface 103 are connected via a bus 100 and communicate with each other.

[0057] The communication interface 103 is used to implement communication between the modules, devices, units and / or equipment in the embodiment of the present invention. The communication interface 103 can also implement data communication with other components such as: external devices, image / data acquisition equipment, databases, external storage, and image / data processing workstations.

[0058] The bus 100 includes hardware, software or both, and couples the components of the computer device to each other. The bus 100 includes but is not limited to at least one of the following: a data bus, an address bus, a control bus, an expansion bus, and a local bus. By way of example and not limitation, bus 100 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 100 may include one or more buses. Although embodiments of the present invention describe and illustrate a particular bus, the present invention contemplates any suitable bus or interconnect.

[0059] The computer can execute the bridge displacement monitoring method based on phase information of the present invention based on the bridge displacement monitoring system acquired based on phase information, thereby realizing bridge displacement monitoring based on phase information.

[0060] In some further embodiments of the present invention, in combination with the above-mentioned bridge displacement monitoring method based on phase information, the embodiments of the present invention provide the following technical solutions: a storage medium having a computer program stored thereon, and the computer program implements the above-mentioned bridge displacement monitoring method based on phase information when executed by a processor.

[0061] Those skilled in the art will appreciate that the logic and / or steps represented in the flowchart or otherwise described herein, for example, may be considered as an ordered list of executable instructions for implementing logical functions, and may be specifically implemented in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute instructions), or in conjunction with such instruction execution systems, devices or apparatuses. For purposes of this specification, "computer-readable medium" may be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in conjunction with such instruction execution systems, devices or apparatuses.

[0062] More specific examples of readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk case (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be a paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, deciphering or, if necessary, processing in another suitable manner, and then stored in a computer memory.

[0063] It should be understood that the various parts of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or a combination thereof: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0064] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0065] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A bridge displacement monitoring method based on phase information, characterized in that: include: Acquire a two-dimensional grating image of the bridge, and pre-process the two-dimensional grating image to obtain a one-dimensional grating image; Sampling and interpolating the one-dimensional grating image to obtain a plurality of moiré fringes; Determine the phase and solve the equation based on the moiré fringes; Solving the phase solution equation to obtain a moiré phase; The bridge displacement is determined based on the moiré phase.

2. The bridge displacement monitoring method based on phase information according to claim 1 is characterized in that: The step of preprocessing the two-dimensional image to obtain a one-dimensional grating image is specifically as follows: The two-dimensional grating image is subjected to low-pass filtering or mean filtering to obtain a one-dimensional grating image.

3. The bridge displacement monitoring method based on phase information according to claim 1 is characterized in that: The step of sampling and interpolating the one-dimensional grating image to obtain a plurality of moiré fringes comprises: Set the sampling interval and a pre-sampled image, placing the first pixel of the first row in the one-dimensional raster image at the position of the first row and the first column in the pre-sampled image; Sequentially place the first row of the one-dimensional grating image The pixels are placed in the first row of the pre-sampled image. Department, is the number of samplings; The first row of the one-dimensional raster image The pixel points are placed in the first row of the pre-sampled image. The position of the column; Sequentially place the first row of the one-dimensional grating image The pixels are placed in the first row of the pre-sampled image. Department; The sampling process is repeated to obtain a number of sampling groups, and interpolation processing is performed on the number of sampling groups to obtain a number of moiré fringes.

4. The bridge displacement monitoring method based on phase information according to claim 1 is characterized in that: The step of determining the phase solution equation based on the plurality of moiré fringes comprises: Determine the coordinates of the moiré fringe Gray value : ； In the formula, , Represents the coordinates in a one-dimensional raster image The modulation gray value, the gray value of the background light intensity, Represents the coordinates in a one-dimensional raster image The phase of is the sampling interval, is the serial number of the moiré fringe; For the gray value Adjust the equation to get the phase solution equation: ； ， ， ； In the formula, , , denote the first, second, and third unknowns respectively; Define the error function : ； In the formula, Indicates Gray value of the moiré fringe; For the error function In , , Find the partial derivative to get the partial derivative equation: ； The partial derivative equation is transformed into a matrix to obtain a matrix equation: ； ； In the formula, To simplify the matrix; A phase solution equation is determined based on the matrix equation.

5. The bridge displacement monitoring method based on phase information according to claim 4 is characterized in that: The step of determining the phase solution equation based on the matrix equation comprises: The matrix equation is simplified by trigonometric functions to obtain a simplified matrix : ； Based on the simplified matrix Substitute into the matrix equation to determine the first unknown , the second unknown , the third unknown : ； Based on the second unknown , the third unknown number Determine the first phase to be determined : ； The first phase to be determined is converted to obtain a second phase to be determined : ； Determine coordinates The second undetermined phase at , based on the second undetermined phase Determine the phase solving the equation: ； ； In the formula, represents the moiré phase to be solved, represents an integer, represents a discrete input, express The true phase of .

6. The bridge displacement monitoring method based on phase information according to claim 1 is characterized in that: The step of solving the phase solution equation to obtain the moiré phase includes: Calculate the discrete inputs in the phase solving equation : ； In the formula, represents the wrapping operator, , , , Respectively , , , The second undetermined phase at ; Based on discrete input Calculate the true phase : ； In the formula, represents discrete cosine transform, , Respectively , The maximum value of The real phase Substitute into the phase solution equation to obtain the moiré phase .

7. The bridge displacement monitoring method based on phase information according to claim 1 is characterized in that: The step of determining the bridge displacement based on the moiré phase comprises: Calculate the phase difference value based on the moiré phase : ； In the formula, , Respectively represent Frame, Frame 2D raster image The moiré phase at Based on the phase difference Calculating bridge displacements : ； In the formula, is the grating spacing.

8. A bridge displacement monitoring system based on phase information, characterized in that: The system comprises: A processing module, used for acquiring a two-dimensional grating image of the bridge, and preprocessing the two-dimensional grating image to obtain a one-dimensional grating image; A sampling module, used for sampling and interpolating the one-dimensional grating image to obtain a plurality of moiré fringes; An equation module, used for solving an equation based on a plurality of said moiré fringes to determine a phase; A solution module, used for solving the phase solution equation to obtain a moiré phase; A displacement module is used to determine the bridge displacement based on the moiré phase.

9. A computer 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, the bridge displacement monitoring method based on phase information as described in any one of claims 1 to 7 is implemented.

10. A storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by the processor, the bridge displacement monitoring method based on phase information as described in any one of claims 1 to 7 is implemented.

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