Bridge structure remote deformation and vibration measurement method and system based on microwave sensing

Abstract

The application provides a bridge structure remote deformation and vibration measurement method and system based on microwave sensing, comprising the following steps: S1, estimating the position of the measured target by using imaging information; S2, phase-modulating the transmission signal of the transmission antenna according to the position of the measured target; S3, mixing the signal reflected by the target with a local oscillation signal and performing low-pass filtering to obtain a multi-channel baseband signal, and obtaining the deformation displacement information of the measured target through demodulation processing; and S4, extracting the deformation displacement information of the measured target through cyclic measurement. The application provides a high-integration, convenient-to-operate, and large-field-of-view monitoring method and system suitable for bad environments such as rainy and foggy days for bridge monitoring. The application arranges multiple transmitter antennas to synchronously transmit radio frequency signals, which are used for beam synthesis and scanning, so as to improve the energy and signal-to-noise ratio of the target reflected signal and realize long-distance measurement of the bridge based on the microwave band.

Description

Technical Field

[0001] This invention relates to the field of measurement technology, specifically to a method and system for remote deformation and vibration measurement of bridge structures based on microwave sensing, and more specifically to a method and system for remote vibration, deformation and torsion measurement of bridge structures based on microwave sensing. Background Technology

[0002] Structural health monitoring of bridges is crucial for ensuring the reliable operation of transportation infrastructure, and this monitoring primarily includes vibration, deflection, and torsion monitoring. As structural health inspection and fault diagnosis become increasingly important aspects of facility maintenance, multi-point synchronous measurement in bridge monitoring holds great promise for future applications.

[0003] Traditional bridge monitoring methods primarily utilize optical, electrical, contact accelerometer, and microwave technologies. However, when using accelerometers for full-field vibration measurement, a large number of sensors are attached to the bridge surface, requiring wiring and networking for simultaneous measurements. On the other hand, laser interferometry-based vibration measurement technology, once installed and aligned with the surface of the object being measured, can achieve long-distance vibration measurements, but it is mainly for single-point measurements, requiring auxiliary mechanical rapid scanning for multi-point measurements. Vision-based vibration measurement technology uses a high-precision camera to magnify the pixel movement of the target, enabling simultaneous measurement of the target within the field of view.

[0004] Accelerometers require extensive wiring and networking, making deployment and maintenance difficult. Laser interferometers have high requirements for the surface quality of the measured target and operate under demanding conditions. Furthermore, due to their high operating frequency, they are prone to scattering loss in rainy or foggy weather, making long-distance measurement impossible. Cameras are significantly affected by environmental factors such as lighting, and their field of view for high-precision measurements is very small. When monitoring bridge structures, image stitching is required, which reduces image measurement accuracy. Microwave sensing technology is limited by its transmission power, making long-distance vibration and deformation measurements impossible. Additionally, the angular resolution of microwave sensing technology depends on the number of receiving channels, significantly limiting its ability to resolve long-distance measurement points. This makes it difficult to achieve multi-point measurement on bridge structures, particularly in resolving lateral torsional measurement points and measuring vibration and deformation.

[0005] Patent document CN113554620A (application number: CN202110834116.5) discloses a bridge deformation measurement system based on multi-mobile phone imaging analysis. The method includes: obtaining a blind zone; identifying a first camera and a second camera as neighboring cameras to the blind zone; segmenting and fitting the images acquired by the first and second cameras to obtain a first set of complete marker lines and a second set of complete marker lines, and calculating the degree of overlap between the marker lines in the two sets; setting zoom weights based on the degree of overlap and parameters such as camera attitude; adjusting the focal length of the neighboring cameras based on the zoom weights until the degree of overlap equals an overlap threshold, thus obtaining complete marker lines; and representing the deformation data by the pixel displacement of each column on the complete marker lines in adjacent frames. However, this invention does not utilize a method of arranging multiple transmitter antennas and synchronously transmitting radio frequency signals. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a method and system for remote deformation and vibration measurement of bridge structures based on microwave sensing.

[0007] A remote deformation and vibration measurement method for bridge structures based on microwave sensing, provided by the present invention, includes:

[0008] Step S1: Estimate the position of the target using imaging information;

[0009] Step S2: Modulate the phase of the transmitted signal of the transmitting antenna according to the location of the target being measured;

[0010] Step S3: Mix the signal reflected by the target with the local oscillator signal and perform low-pass filtering to obtain a multi-channel baseband signal. Then, demodulate the signal to obtain the deformation displacement information of the target under test.

[0011] Step S4: Extract the deformation and displacement information of the target object through cyclic measurement.

[0012] Preferably, in step S1:

[0013] The position θ of the target under test is estimated using microwave imaging or visual imaging information;

[0014] Determine the placement of the microwave transceiver and image the echo data:

[0015] Map = 2DFFT(s) B (p,θ s ))

[0016] Where 2DFFT is a two-dimensional Fourier transform, Map is the location image of the bridge target, and s B (p,θ s () represents the multi-channel baseband signal of the microwave transceiver during its p-th operating cycle;

[0017] The areas with larger amplitudes indicate the locations where the target is being measured, thus providing an estimated information about the target's location.

[0018] Preferably, in step S2:

[0019] For different target positions θ, the FMCW transmission signals from multiple transmitting antennas are phase-modulated;

[0020] The angle between the position of the target being measured and the line perpendicular to the array is θ1, θ2, ..., θ. s For those located at angle θ s To determine the target to be measured, construct the phase modulation vector:

[0021]

[0022] Where, d k (k = 2, ..., K) represents the distance between the k-th transmitting antenna and the first transmitting antenna, K is the number of transmitting antennas, and λ c The wavelength corresponding to the center frequency of a linear frequency modulated continuous wave;

[0023] The initial phases of each transmit antenna are set to Φ1, Φ2, ..., Φ based on the phase modulation vector. K , where Φ k It is the k-th element of the phase modulation vector Φ.

[0024] Preferably, in step S3:

[0025] During the p-th duty cycle, the beam scanning angle θ is used. s The multi-channel baseband signal of the microwave transceiver acquired by phase modulation is s B (p,θ s The deformation displacement information of the measured target is obtained by demodulation processing (m), and m is used to obtain the deformation displacement information of the measured target.

[0026] The deformation displacement value is calculated as follows:

[0027]

[0028] Where x(p,θ) s R) represents the p-th working cycle, and θ represents the beam scanning angle. s The displacement sequence element value of the target being scanned at a distance of R from the current scanning angle, arg[·] is the operation of taking complex phase values, N is the number of single-channel baseband signal elements in each sweep cycle, n is the index of single-channel baseband signal elements in each sweep cycle, and T s The sampling frequency and time of the baseband signal; s B (p,θ s iT,nT sLet be the p-th working cycle, and let θ be the beam scanning angle. s The matrix consists of M baseband signals from various channels. The column vectors of the matrix represent the baseband signals of the m-th channel (m = 1, 2, ..., M), where j is the imaginary unit. d is the estimated beat frequency corresponding to the distance between the measured target or measuring point. rxm Let d be the distance from the m-th receiving antenna to the first receiving antenna, where d rx1 =0.

[0029] Preferably, in step S4:

[0030] By matching phase interference of multiple frequency sweep cycles and imaging of multiple different frequency sweep cycles, the position of the target under test in different frequency sweep cycles is obtained, and the deformation information of the target medium surface at the relevant position is extracted.

[0031] For different working periods p = 1, 2, ..., P, the deformation displacement time history signal sequence of the s-th monitoring point is obtained as [x(1, θ s ),…,x(p,θ s ),...]; Obtain deformation displacement information; Repeatedly measure the displacement of multiple points, including parallel measurement points distributed on the left, middle and right sides of the structure, and obtain the deformation data of the measured target by comparing the displacement relationship between each point.

[0032] A remote deformation and vibration measurement system for bridge structures based on microwave sensing, according to the present invention, includes:

[0033] Module M1: Uses imaging information to estimate the position of the target being measured;

[0034] Module M2: Modulates the phase of the transmitted signal from the transmitting antenna based on the location of the target being measured;

[0035] Module M3: Mixes the signal reflected from the target with the local oscillator signal and performs low-pass filtering to obtain a multi-channel baseband signal. The deformation and displacement information of the target under test is obtained through demodulation processing.

[0036] Module M4: Extracts deformation and displacement information of the target object through cyclic measurement.

[0037] Preferably, in module M1:

[0038] The position θ of the target under test is estimated using microwave imaging or visual imaging information;

[0039] Determine the placement of the microwave transceiver and image the echo data:

[0040] Map = 2DFFT(s) B (p,θ s ))

[0041] Where 2DFFT is a two-dimensional Fourier transform, Map is the location image of the bridge target, and s B (p,θ s () represents the multi-channel baseband signal of the microwave transceiver during its p-th operating cycle;

[0042] The areas with larger amplitudes indicate the locations where the target is being measured, thus providing an estimated information about the target's location.

[0043] Preferably, in module M2:

[0044] For different target positions θ, the FMCW transmission signals from multiple transmitting antennas are phase-modulated;

[0045] The angle between the position of the target being measured and the line perpendicular to the array is θ1, θ2, ..., θ s For those located at angle θ s To determine the target to be measured, construct the phase modulation vector:

[0046]

[0047] Where, d k (k = 2, ..., K) represents the distance between the k-th transmitting antenna and the first transmitting antenna, K is the number of transmitting antennas, and λ c The wavelength corresponding to the center frequency of a linear frequency modulated continuous wave;

[0048] The initial phases of each transmit antenna are set to Φ1, Φ2, ..., Φ based on the phase modulation vector. K , where Φ k It is the k-th element of the phase modulation vector Φ.

[0049] Preferably, in module M3:

[0050] During the p-th duty cycle, the beam scanning angle θ is used. s The multi-channel baseband signal of the microwave transceiver acquired by phase modulation is s B (p,θ s The deformation displacement information of the measured target is obtained by demodulation processing (m), and m is used to obtain the deformation displacement information of the measured target.

[0051] The deformation displacement value is calculated as follows:

[0052]

[0053] Where x(p,θ) s R) represents the p-th working cycle, and θ represents the beam scanning angle. sThe displacement sequence element value of the target being scanned at a distance of R from the current scanning angle, arg[·] is the operation of taking complex phase values, N is the number of single-channel baseband signal elements in each sweep cycle, n is the index of single-channel baseband signal elements in each sweep cycle, and T s The sampling frequency and time of the baseband signal; s B (p,θ s iT,nT s Let be the p-th working cycle, and let θ be the beam scanning angle. s The matrix consists of M baseband signals from various channels. The column vectors of the matrix represent the baseband signals of the m-th channel (m = 1, 2, ..., M), where j is the imaginary unit. d is the estimated beat frequency corresponding to the distance between the measured target or measuring point. rxm Let d be the distance from the m-th receiving antenna to the first receiving antenna, where d rx1 =0.

[0054] Preferably, in module M4:

[0055] By matching phase interference of multiple frequency sweep cycles and imaging of multiple different frequency sweep cycles, the position of the target under test in different frequency sweep cycles is obtained, and the deformation information of the target medium surface at the relevant position is extracted.

[0056] For different working periods p = 1, 2, ..., P, the deformation displacement time history signal sequence of the s-th monitoring point is obtained as [x(1, θ s ),…,x(p,θ s ),...]; Obtain deformation displacement information; Repeatedly measure the displacement of multiple points, including parallel measurement points distributed on the left, middle and right sides of the structure, and obtain the deformation data of the measured target by comparing the displacement relationship between each point.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] 1. This invention provides a highly integrated, easy-to-operate, and wide-field-of-view monitoring method and system for bridge monitoring, suitable for harsh environments such as rain and fog.

[0059] 2. In remote bridge measurement, the reflected energy of microwave antennas based on active excitation is relatively small. This invention arranges multiple transmitter antennas and transmits radio frequency signals synchronously for beamforming and scanning, thereby improving the energy and signal-to-noise ratio of the target reflected signal and realizing long-distance bridge measurement based on the microwave band.

[0060] 3. In order to measure the torsion of bridges, it is necessary to improve the resolution. This invention achieves a larger virtual aperture and higher resolution by increasing the spacing between the transmitting antennas and combining them with the receiving antenna. Attached Figure Description

[0061] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0062] Figure 1 This is a schematic diagram showing the distribution of bridge structure monitoring points and the installation location of the microwave transceiver in an embodiment of the present invention;

[0063] Figure 2 This is a flowchart of a method for remote vibration, deformation, and torsion measurement of bridge structures according to an embodiment of the present invention;

[0064] Figure 3 This is a schematic diagram showing the installation position of the microwave transceiver during a bridge measurement experiment according to an embodiment of the present invention;

[0065] Figure 4 This is a diagram showing the displacement results of bridge measuring points when a train passes on the left side during a bridge measurement experiment according to an embodiment of the present invention.

[0066] Figure 5 This is a diagram showing the displacement results of bridge measuring points when a train passes on the right side during a bridge measurement experiment according to an embodiment of the present invention.

[0067] Figure 6 This is a diagram showing the displacement results of bridge measuring points when a truck passes over them during a bridge measurement experiment according to an embodiment of the present invention.

[0068] Figure 7 This is a schematic diagram of the components of a remote vibration, deformation, and torsion measurement system for bridge structures according to an embodiment of the present invention.

[0069] Figure 8 This is a schematic diagram of the microwave transceiver components according to an embodiment of the present invention. Detailed Implementation

[0070] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0071] Example 1:

[0072] This invention relates to the field of bridge monitoring and vibration measurement technology, and in particular to a method and system for remote vibration, deformation and torsion measurement of bridge structures based on microwave sensing.

[0073] 1. The present invention aims to provide a highly integrated, easy-to-operate monitoring method and system for bridge monitoring that is suitable for harsh environments such as rain and fog, and has a wide field of view.

[0074] 2. In remote bridge measurement, this invention needs to improve the energy and signal-to-noise ratio of the target reflected signal.

[0075] 3. To enable the measurement of bridge torsion, the azimuth resolution was improved.

[0076] According to the present invention, a remote deformation and vibration measurement method for bridge structures based on microwave sensing is provided, such as... Figures 1-8 As shown, it includes:

[0077] Step S1: Estimate the position of the target using imaging information;

[0078] Specifically, in step S1:

[0079] The position θ of the target under test is estimated using microwave imaging or visual imaging information;

[0080] Determine the placement of the microwave transceiver and image the echo data:

[0081] Map = 2DFFT(s) B (p,θ s ))

[0082] Where 2DFFT is a two-dimensional Fourier transform, Map is the location image of the bridge target, and s B (p,θ s () represents the multi-channel baseband signal of the microwave transceiver during its p-th operating cycle;

[0083] The areas with larger amplitudes indicate the locations where the target is being measured, thus providing an estimated information about the target's location.

[0084] Step S2: Modulate the phase of the transmitted signal of the transmitting antenna according to the location of the target being measured;

[0085] Specifically, in step S2:

[0086] For different target positions θ, the FMCW transmission signals from multiple transmitting antennas are phase-modulated;

[0087] The angle between the position of the target being measured and the line perpendicular to the array is θ1, θ2, ..., θ s For those located at angle θ s To determine the target to be measured, construct the phase modulation vector:

[0088]

[0089] Where, d k (k = 2, ..., K) represents the distance between the k-th transmitting antenna and the first transmitting antenna, K is the number of transmitting antennas, and λ c The wavelength corresponding to the center frequency of a linear frequency modulated continuous wave;

[0090] The initial phases of each transmit antenna are set to Φ1, Φ2, ..., Φ based on the phase modulation vector. K , where Φ k It is the k-th element of the phase modulation vector Φ.

[0091] Step S3: Mix the signal reflected by the target with the local oscillator signal and perform low-pass filtering to obtain a multi-channel baseband signal. Demodulate the signal to obtain the deformation displacement information of the target under test.

[0092] Specifically, in step S3:

[0093] During the p-th duty cycle, the beam scanning angle θ is used. s The multi-channel baseband signal of the microwave transceiver acquired by phase modulation is s B (p,θ s The deformation displacement information of the measured target is obtained by demodulation processing (m), and m is used to obtain the deformation displacement information of the measured target.

[0094] The deformation displacement value is calculated as follows:

[0095]

[0096] Where x(p,θ) s R) represents the p-th working cycle, and θ represents the beam scanning angle. s The displacement sequence element value of the target being scanned at a distance of R from the current scanning angle, arg[·] is the operation of taking complex phase values, N is the number of single-channel baseband signal elements in each sweep cycle, n is the index of single-channel baseband signal elements in each sweep cycle, and T s The sampling frequency and time of the baseband signal; s B (p,θ s iT,nT s Let be the p-th working cycle, and let θ be the beam scanning angle. s The matrix consists of M baseband signals from various channels. The column vectors of the matrix represent the baseband signals of the m-th channel (m = 1, 2, ..., M), where j is the imaginary unit. d is the estimated beat frequency corresponding to the distance between the measured target or measuring point. rxm Let d be the distance from the m-th receiving antenna to the first receiving antenna, where d rx1 =0.

[0097] Step S4: Extract the deformation and displacement information of the target object through cyclic measurement.

[0098] Specifically, in step S4:

[0099] By matching phase interference of multiple frequency sweep cycles and imaging of multiple different frequency sweep cycles, the position of the target under test in different frequency sweep cycles is obtained, and the deformation information of the target medium surface at the relevant position is extracted.

[0100] For different working periods p = 1, 2, ..., P, the deformation displacement time history signal sequence of the s-th monitoring point is obtained as [x(1, θ s ),…,x(p,θ s ),...]; Obtain deformation displacement information; Repeatedly measure the displacement of multiple points, including parallel measurement points distributed on the left, middle and right sides of the structure, and obtain the deformation data of the measured target by comparing the displacement relationship between each point.

[0101] Example 2:

[0102] Example 2 is a preferred example of Example 1, and is used to illustrate the present invention in more detail.

[0103] The present invention also provides a remote deformation and vibration measurement system for bridge structures based on microwave sensing. The remote deformation and vibration measurement system for bridge structures based on microwave sensing can be implemented by executing the process steps of the remote deformation and vibration measurement method for bridge structures based on microwave sensing. That is, those skilled in the art can understand the remote deformation and vibration measurement method for bridge structures based on microwave sensing as a preferred embodiment of the remote deformation and vibration measurement system for bridge structures based on microwave sensing.

[0104] A remote deformation and vibration measurement system for bridge structures based on microwave sensing, according to the present invention, includes:

[0105] Module M1: Uses imaging information to estimate the position of the target being measured;

[0106] Specifically, in module M1:

[0107] The position θ of the target under test is estimated using microwave imaging or visual imaging information;

[0108] Determine the placement of the microwave transceiver and image the echo data:

[0109] Map = 2DFFT(s) B (p,θ s ))

[0110] Where 2DFFT is a two-dimensional Fourier transform, Map is the location image of the bridge target, and s B (p,θ s () represents the multi-channel baseband signal of the microwave transceiver during its p-th operating cycle;

[0111] The areas with larger amplitudes indicate the locations where the target is being measured, thus providing an estimated information about the target's location.

[0112] Module M2: Modulates the phase of the transmitted signal from the transmitting antenna based on the location of the target being measured;

[0113] Specifically, in module M2:

[0114] For different target positions θ, the FMCW transmission signals from multiple transmitting antennas are phase-modulated;

[0115] The angle between the position of the target being measured and the line perpendicular to the array is θ1, θ2, ..., θ s For those located at angle θ s To determine the target to be measured, construct the phase modulation vector:

[0116]

[0117] Where, d k (k = 2, ..., K) represents the distance between the k-th transmitting antenna and the first transmitting antenna, K is the number of transmitting antennas, and λ c The wavelength corresponding to the center frequency of a linear frequency modulated continuous wave;

[0118] The initial phases of each transmit antenna are set to Φ1, Φ2, ..., Φ based on the phase modulation vector. K , where Φ k It is the k-th element of the phase modulation vector Φ.

[0119] Module M3: Mixes the signal reflected from the target with the local oscillator signal and performs low-pass filtering to obtain a multi-channel baseband signal. The deformation and displacement information of the target under test is obtained through demodulation processing.

[0120] Specifically, in module M3:

[0121] During the p-th duty cycle, the beam scanning angle θ is used. s The multi-channel baseband signal of the microwave transceiver acquired by phase modulation is s B (p,θ s The deformation displacement information of the measured target is obtained by demodulation processing (m), and m is used to obtain the deformation displacement information of the measured target.

[0122] The deformation displacement value is calculated as follows:

[0123]

[0124] Where x(p,θ) s R) represents the p-th working cycle, and θ represents the beam scanning angle. sThe displacement sequence element value of the target being scanned at a distance of R from the current scanning angle, arg[·] is the operation of taking complex phase values, N is the number of single-channel baseband signal elements in each sweep cycle, n is the index of single-channel baseband signal elements in each sweep cycle, and T s The sampling frequency and time of the baseband signal; s B (p,θ s iT,nT s Let be the p-th working cycle, and let θ be the beam scanning angle. s The matrix consists of M baseband signals from various channels. The column vectors of the matrix represent the baseband signals of the m-th channel (m = 1, 2, ..., M), where j is the imaginary unit. d is the estimated beat frequency corresponding to the distance between the measured target or measuring point. rxm Let d be the distance from the m-th receiving antenna to the first receiving antenna, where d rx1 =0.

[0125] Module M4: Extracts deformation and displacement information of the target object through cyclic measurement.

[0126] Specifically, in module M4:

[0127] By matching phase interference of multiple frequency sweep cycles and imaging of multiple different frequency sweep cycles, the position of the target under test in different frequency sweep cycles is obtained, and the deformation information of the target medium surface at the relevant position is extracted.

[0128] For different working periods p = 1, 2, ..., P, the deformation displacement time history signal sequence of the s-th monitoring point is obtained as [x(1, θ s ),…,x(p,θ s ),...]; Obtain deformation displacement information; Repeatedly measure the displacement of multiple points, including parallel measurement points distributed on the left, middle and right sides of the structure, and obtain the deformation data of the measured target by comparing the displacement relationship between each point.

[0129] Example 3:

[0130] Example 3 is a preferred example of Example 1, and is used to illustrate the present invention in more detail.

[0131] The purpose of this invention is to overcome the defects and shortcomings of existing technologies and provide a method and system for remote vibration, deformation and torsion measurement of bridge structures based on microwave sensing. To achieve the above objective, this invention is implemented through the following technical solutions:

[0132] A method for remote vibration, deformation, and torsion measurement of bridge structures based on microwave sensing, characterized by the following steps:

[0133] Step S1: Adjust the microwave transceiver so that it faces the area of ​​the bridge structure to be measured.

[0134] Step S2: In each working cycle, the phase of the transmitted signals of multiple transmitting antennas of the microwave transceiver is adjusted according to the bridge structure measuring points or target locations.

[0135] Assume that the angles between the locations of multiple measurement points or targets and the lines perpendicular to the array are θ1, θ2, ..., θ s ..., for those located at angle θ s For the measurement points to be measured, construct the phase modulation vector:

[0136]

[0137] Where d k (k = 2, ..., K) represents the distance between the k-th transmitting antenna and the first transmitting antenna, K is the number of transmitting antennas, and λ c The wavelength corresponding to the center frequency of a linear frequency modulated continuous wave;

[0138] The initial phases of each transmit antenna are set to Φ1, Φ2, ..., Φ based on the phase modulation vector. K , where Φ k This is the k-th element of the phase modulation vector Φ;

[0139] Step S3: In the p-th work cycle, use angle θ s The multi-channel baseband signal of the microwave transceiver obtained by phase modulation in step S2 is s B (p,θ s The vibration and deformation displacement information of the measured point or target is obtained through demodulation processing, where m is the baseband signal of the m-th receiving antenna.

[0140] The displacement value is calculated as follows:

[0141]

[0142] In the formula, x(p,θ) s R) represents the position at angle θ during the p-th working cycle. s Furthermore, the displacement sequence element values ​​of the target or measuring point at a distance from the transceiver R, arg[·] represents the operation of taking complex phase values, N is the number of single-channel baseband signal elements in each frequency sweep cycle, n is the index of the single-channel baseband signal element in each frequency sweep cycle, and T s The sampling frequency and time of the baseband signal; s B (p,θ s (m) represents the p-th working cycle, and the beam scanning angle is θ. s The matrix is ​​composed of the baseband signals of the m-th channel, and the column vectors of the matrix are the baseband signals of the m-th (m=1,2,...,M) channels, where j is the imaginary unit. d is the estimated beat frequency corresponding to the distance between the measured target or measuring point. rxm (m=1,…,M) represent the distances from the m-th receiving antenna to the first receiving antenna, where d rx1 =0;

[0143] Step S4: Extract vibration and deformation information of the measured points or targets of the tested structure through cyclic measurement over multiple working cycles.

[0144] For different working cycles p = 1, 2, ..., P, the deformation and vibration displacement time history signal sequence of the s-th monitoring point is obtained as [x(1, θ s ,R),…,x(p,θ s Vibration and deformation displacement information can be obtained by [ ,R),...]. Repeat steps S2-S4 to measure the displacement of multiple points, including parallel measurement points distributed on the left, middle and right sides of the bridge structure. By comparing the displacement relationships between the points, the bridge deformation and torsion data can be obtained.

[0145] Example 4:

[0146] Example 4 is a preferred example of Example 1, which is used to illustrate the present invention in more detail.

[0147] Methods for remote vibration, deformation and torsion measurement of bridge structures:

[0148] like Figure 1 As shown, based on the distribution of monitoring points on the bridge structure and the installation location of the microwave transceiver, the scanning angle sequence of the microwave transceiver's transmitting beam is determined. After the microwave transceiver transmits the beam, it receives the echo signal and samples the baseband signal after hardware processing. Based on the principle of phase interferometry, the deformation and vibration displacement values ​​of each measurement point in each target direction are extracted sequentially. According to the above method, cyclic measurements are carried out to obtain the waveforms of deformation and vibration displacement of all monitoring points, realizing automated monitoring of deformation and vibration displacement of all measurement points on the bridge structure.

[0149] This case study includes the following steps:

[0150] Step S1: Estimate the position θ to be measured using microwave imaging or visual imaging information. s

[0151] Determine the placement of the microwave transceiver, such as Figure 3 Imaging the echo data can be specifically performed as follows:

[0152] Map = 2DFFT(s) B (p,θ s ))

[0153] Where 2DFFT is the two-dimensional Fourier transform, Map is the location image of the bridge target, and s B(p,θ s () represents the multi-channel baseband signal of the microwave transceiver during its p-th operating cycle;

[0154] The area with the larger amplitude indicates the location of the target, from which the estimated location of the target can be obtained.

[0155] The target's location can also be estimated through vision or other imaging methods.

[0156] Step S2: For different measurement areas θ s Phase modulation is performed on the FMCW transmission signals from multiple transmitting antennas.

[0157] Assume the angle between the location of the target to be measured and the line perpendicular to the array is θ1, θ2, ..., θ s ..., for those located at angle θ s To determine the target to be measured, construct the phase modulation vector:

[0158]

[0159] Where d k (k = 2, ..., K) represents the distance between the k-th transmitting antenna and the first transmitting antenna, K is the number of transmitting antennas, and λ c The wavelength corresponding to the center frequency of a linear frequency modulated continuous wave;

[0160] The initial phases of each transmit antenna are set to Φ1, Φ2, ..., Φ based on the phase modulation vector. K , where Φ k This is the k-th element of the phase modulation vector Φ;

[0161] Step S3: Mix the signal reflected from the target with the local oscillator signal and perform low-pass filtering to obtain a multi-channel baseband signal. Demodulate the signal to obtain the vibration displacement of the target area.

[0162] The vibration displacement value is calculated as follows:

[0163]

[0164] In the formula, x(p,θ) s R) represents the p-th working cycle, and θ represents the beam scanning angle. s The displacement sequence element value of the target or measuring point at a current scanning angle distance of R, arg[·] is the operation of taking complex phase values, N is the number of single-channel baseband signal elements in each sweep cycle, n is the index of single-channel baseband signal elements in each sweep cycle, and T s The sampling frequency and time of the baseband signal; s B (p,θ s (m) represents the p-th working cycle, and the beam scanning angle is θ.s The matrix is ​​composed of the baseband signals of the m-th channel, and the column vectors of the matrix are the baseband signals of the m-th (m=1,2,...,M) channels, where j is the imaginary unit. d is the estimated beat frequency corresponding to the distance between the measured target or measuring point. rxm (m=1,…,M) represent the distances from the m-th receiving antenna to the first receiving antenna, where d rx1 =0;

[0165] Step S4: By matching the phase interference of multiple frequency sweep cycles and the imaging of multiple different frequency sweep cycles, the position of the target in different frequency sweep cycles is obtained, and the vibration information of the target medium surface at the relevant position is extracted.

[0166] With different working cycles p = 1, 2, ..., P, the deformation and vibration displacement time history signal sequence of the s-th monitoring point is obtained as [x(1, θ s ,R),…,x(p,θ s Vibration information can be obtained by using [,R),...].

[0167] Step S5: Reconstruct the multi-point displacement of the bridge to achieve bridge deformation and torsion monitoring.

[0168] By measuring the displacement of multiple points through steps S1-S4, including parallel measurement points distributed on the left, middle and right sides of the bridge structure, the deformation and torsion data of the bridge can be obtained by comparing the displacement relationships between the points. Figure 3 This is the Songpu Bridge in Shanghai, spanning the Huangpu River, and is used by both high-speed and freight trains. We primarily measure the displacement of three points (left, center, and right) on the bridge's cross-section. This allows us to quantify the key dynamic deflection and torsion under different types and loads of train excitation. For example... Figure 4 As shown, when a high-speed train passes, the bridge structure exhibits significant deflection and vibration, with a larger displacement on the left side, indicating that the train is traveling on the left. Figure 5 The large displacement at the right-hand side indicates that the train is traveling on the right. Simultaneously, we can also observe a certain degree of torsional deflection on the bridge. Figure 6 Measurements were described when a freight train excited a bridge. Because freight trains are heavier than high-speed trains, the deflection is much greater. On the other hand, due to their lower speed and longer length, the deformation caused by the freight train lasted for approximately 50 seconds. Furthermore, it can be seen that the deflection from second 30 to second 70 is smaller than that from second 26. This is because the front compartment is fully loaded, while the rear compartment is lighter or empty. Therefore, microwave sensing-based methods can effectively monitor bridge vibration and deflection and identify the corresponding train load.

[0169] Remote vibration, deformation, and torsion measurement systems for bridge structures, such as Figure 7 As shown, it includes:

[0170] A microwave transceiver is used to transmit linear frequency modulated continuous wave signals, receive echo signals, perform mixing and filtering, output baseband signals, and achieve spatial scanning of the synthesized beam through phase shift control.

[0171] like Figure 8 As shown, the microwave transceiver includes a microwave signal source, a power divider, a mixer, a phase shifter, a power amplifier, a transmitting antenna array, and a receiving antenna array. The signal source is connected to the power divider, with one path radiating a signal through the transmitting antenna and the other path serving as a local oscillator signal for mixing. The phase shifter is connected to the transmitting antenna and is used to adjust the phase of the transmitted antenna signal to oriented the synthesized beam towards the target angle. The receiving antenna array is connected to the amplifier, and the amplified output signal is connected to the mixer, where it is mixed with the local oscillator signal to output a baseband signal.

[0172] The controller and processor are used to control the beam scanning, baseband signal acquisition, and deformation and vibration displacement extraction of the measured points of the microwave transceiver.

[0173] The control and processor includes a scanning control unit and a signal acquisition and processing unit. The scanning control unit is used for phase shift control of the transmitting antenna channel, scanning speed control, and control of other conventional parameters of the microwave transceiver. The signal acquisition and processing unit is used for synchronous acquisition of multi-channel baseband signals, and for processing the acquired signals to extract vibration and deformation displacement values ​​of the target or measurement point.

[0174] Storage and output module: Used to save or display the deformation and vibration displacement sequence values ​​or waveforms of the measured points of the bridge structure, the identification and elimination information of abnormal working conditions, and to transmit relevant information to the data platform as needed.

[0175] The data transmission methods of the storage and output modules include, but are not limited to, wired transmission methods for analog output and digital communication, as well as Bluetooth, Wi-Fi, wireless networks or other wireless transmission methods.

[0176] Those skilled in the art will understand that, in addition to implementing the system, apparatus, and their modules provided by this invention in purely computer-readable program code, the same program can be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, the system, apparatus, and their modules provided by this invention can be considered a hardware component, and the modules included therein for implementing various programs can also be considered structures within the hardware component; alternatively, modules for implementing various functions can be considered both software programs implementing the method and structures within the hardware component.

[0177] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. A method for remote deformation and vibration measurement of bridge structures based on microwave sensing, characterized in that, include: Step S1: Estimate the position of the target using imaging information; Step S2: Modulate the phase of the transmitted signal of the transmitting antenna according to the location of the target being measured; Step S3: Mix the signal reflected by the target with the local oscillator signal and perform low-pass filtering to obtain a multi-channel baseband signal. Demodulate the signal to obtain the deformation displacement information of the target under test. Step S4: Extract the deformation and displacement information of the target object through cyclic measurement.

2. The method for remote deformation and vibration measurement of bridge structures based on microwave sensing according to claim 1, characterized in that, In step S1: The position θ of the target under test is estimated using microwave imaging or visual imaging information; Determine the placement of the microwave transceiver and image the echo data: Map=2DFFT(s B (p,θ s )) Where 2DFFT is a two-dimensional Fourier transform, Map is the location image of the bridge target, and s B (p,θ s () represents the multi-channel baseband signal of the microwave transceiver during its p-th operating cycle; The areas with larger amplitudes indicate the locations where the target is being measured, thus providing an estimated information about the target's location.

3. The method for remote deformation and vibration measurement of bridge structures based on microwave sensing according to claim 1, characterized in that, In step S2: For different target positions θ, the FMCW transmission signals from multiple transmitting antennas are phase-modulated; The angle between the position of the target being measured and the line perpendicular to the array is θ1, θ2, ..., θ. s For those located at angle θ s To determine the target to be measured, construct the phase modulation vector: Where, d k (k = 2, ..., K) represents the distance between the k-th transmitting antenna and the first transmitting antenna, K is the number of transmitting antennas, and λ c The wavelength corresponding to the center frequency of a linear frequency modulated continuous wave; The initial phases of each transmit antenna are set to Φ1, Φ2, ..., Φ based on the phase modulation vector. K , where Φ k It is the k-th element of the phase modulation vector Φ.

4. The method for remote deformation and vibration measurement of bridge structures based on microwave sensing according to claim 1, characterized in that, In step S3: During the p-th duty cycle, the beam scanning angle θ is used. s The multi-channel baseband signal of the microwave transceiver acquired by phase modulation is s B (p,θ s The deformation displacement information of the measured target is obtained by demodulation processing (m), and m is used to obtain the deformation displacement information of the measured target. The deformation displacement value is calculated as follows: Where x(p,θ) s R) represents the p-th working cycle, and θ represents the beam scanning angle. s The displacement sequence element value of the target being scanned at a distance of R from the current scanning angle, arg[·] is the operation of taking complex phase values, N is the number of single-channel baseband signal elements in each sweep cycle, n is the index of single-channel baseband signal elements in each sweep cycle, and T s The sampling frequency and time of the baseband signal; s B (p,θ s iT,nT s ) represents the p-th working cycle, with a beam scanning angle of θ. s The matrix consists of M baseband signals from various channels. The column vectors of the matrix represent the baseband signals of the m-th channel (m = 1, 2, ..., M), where j is the imaginary unit. d is the estimated beat frequency corresponding to the distance between the measured target or measuring point. rxm Let d be the distance from the m-th receiving antenna to the first receiving antenna, where d rx1 =0.

5. The method for remote deformation and vibration measurement of bridge structures based on microwave sensing according to claim 1, characterized in that, In step S4: By matching phase interference of multiple frequency sweep cycles and imaging of multiple different frequency sweep cycles, the position of the target under test in different frequency sweep cycles is obtained, and the deformation information of the target medium surface at the relevant position is extracted. For different working periods p = 1, 2, ..., P, the deformation displacement time history signal sequence of the s-th monitoring point is obtained as [x(1, θ s ),…,x(p,θ s ),...]; Obtain deformation and displacement information; repeatedly measure the displacement of multiple points, including parallel measurement points distributed on the left, middle and right sides of the structure, and obtain the deformation data of the target by comparing the displacement relationship between the points.

6. A remote deformation and vibration measurement system for bridge structures based on microwave sensing, characterized in that, include: Module M1: Uses imaging information to estimate the position of the target being measured; Module M2: Modulates the phase of the transmitted signal from the transmitting antenna based on the location of the target being measured; Module M3: Mixes the signal reflected from the target with the local oscillator signal and performs low-pass filtering to obtain a multi-channel baseband signal. The deformation and displacement information of the target under test is obtained through demodulation processing. Module M4: Extracts deformation and displacement information of the target object through cyclic measurement.

7. The remote deformation and vibration measurement system for bridge structures based on microwave sensing according to claim 6, characterized in that, In module M1: The position θ of the target under test is estimated using microwave imaging or visual imaging information; Determine the placement of the microwave transceiver and image the echo data: Map=2DFFT(s B (p,θ s )) Where 2DFFT is a two-dimensional Fourier transform, Map is the location image of the bridge target, and s B (p,θ s () represents the multi-channel baseband signal of the microwave transceiver during its p-th operating cycle; The areas with larger amplitudes indicate the locations where the target is being measured, thus providing an estimated information about the target's location.

8. The remote deformation and vibration measurement system for bridge structures based on microwave sensing according to claim 6, characterized in that, In module M2: For different target positions θ, the FMCW transmission signals from multiple transmitting antennas are phase-modulated; The angle between the position of the target being measured and the line perpendicular to the array is θ1, θ2, ..., θ. s For those located at angle θ s To determine the target to be measured, construct the phase modulation vector: Where, d k (k = 2, ..., K) represents the distance between the k-th transmitting antenna and the first transmitting antenna, K is the number of transmitting antennas, and λ c The wavelength corresponding to the center frequency of a linear frequency modulated continuous wave; The initial phases of each transmit antenna are set to Φ1, Φ2, ..., Φ based on the phase modulation vector. K , where Φ k It is the k-th element of the phase modulation vector Φ.

9. The remote deformation and vibration measurement system for bridge structures based on microwave sensing according to claim 6, characterized in that, In module M3: During the p-th duty cycle, the beam scanning angle θ is used. s The multi-channel baseband signal of the microwave transceiver acquired by phase modulation is s B (p,θ s The deformation displacement information of the measured target is obtained by demodulation processing (m), and m is used to obtain the deformation displacement information of the measured target. The deformation displacement value is calculated as follows: Where x(p,θ) s R) represents the p-th working cycle, and θ represents the beam scanning angle. s The displacement sequence element value of the target being scanned at a distance of R from the current scanning angle, arg[·] is the operation of taking complex phase values, N is the number of single-channel baseband signal elements in each sweep cycle, n is the index of single-channel baseband signal elements in each sweep cycle, and T s The sampling frequency and time of the baseband signal; s B (p,θ s iT,nT s ) represents the p-th working cycle, with a beam scanning angle of θ. s The matrix consists of M baseband signals from various channels. The column vectors of the matrix represent the baseband signals of the m-th channel (m = 1, 2, ..., M), where j is the imaginary unit. d is the estimated beat frequency corresponding to the distance between the measured target or measuring point. rxm Let d be the distance from the m-th receiving antenna to the first receiving antenna, where d rx1 =0.

10. The remote deformation and vibration measurement system for bridge structures based on microwave sensing according to claim 6, characterized in that, In module M4: By matching phase interference of multiple frequency sweep cycles and imaging of multiple different frequency sweep cycles, the position of the target under test in different frequency sweep cycles is obtained, and the deformation information of the target medium surface at the relevant position is extracted. For different working periods p = 1, 2, ..., P, the deformation displacement time history signal sequence of the s-th monitoring point is obtained as [x(1, θ s ),…,x(p,θ s ),...]; Obtain deformation and displacement information; repeatedly measure the displacement of multiple points, including parallel measurement points distributed on the left, middle and right sides of the structure, and obtain the deformation data of the target by comparing the displacement relationship between the points.

Images