Cable damage identification and positioning method and device based on millimeter wave radar

Abstract

The present invention discloses a method and device for identifying and locating cable damage based on millimeter wave radar, which relates to the technical field of cable flaw detection, including: vibrating the preset position of the target bridge cable; based on the millimeter wave radar, continuously sampling the vibration displacement signals of multiple monitoring points on the target bridge cable; based on the interference calculation of the sampled complex signal, obtaining the vibration time history curve corresponding to each monitoring point; performing discrete Fourier transform on the vibration time history curve to obtain the first N-order vibration frequency and the first N-order vibration mode corresponding to each monitoring point, and comparing them with the first N-order vibration frequency and the first N-order vibration mode of the preset monitoring point to determine whether the target bridge cable is damaged; and locating the damage of the target bridge cable. The present invention can realize the identification and positioning of cable damage efficiently, safely, with high precision, in multi-point synchronization, and all-weather and all-day, saving labor costs and greatly improving the efficiency and accuracy of damage identification and positioning.

Description

Technical Field

[0001] The present invention relates to the technical field of cable flaw detection, and in particular to a method and device for identifying and locating cable damage based on millimeter wave radar. Background Art

[0002] For cable-stayed bridges (such as cable-stayed bridges, suspension bridges, and hanger arch bridges), cables or hangers are the main load-bearing components, and their cable force value is an important key parameter for evaluating the health status of the structure. The breakage of the cable often easily causes the overall collapse of the bridge. When a break occurs at a certain position, the vibration mode at that position will inevitably change. The vibration mode change graph method can easily locate the damaged position when the cable is severely damaged.

[0003] However, the vibration modes of cables or hangers in current projects are often obtained through traditional acceleration sensors. This method and device have many disadvantages: 1) It is difficult to arrange acceleration sensors in the middle and upper parts of the cables. They can only be collected at the ends of the cables close to the bridge deck, which cannot cover all positions of the cables, and the measurement results are easily interfered by the end cable shock absorbers; 2) There will be a protective sheath on the outside of the cable surface. The aging of the sheath will cause the sensor to be unable to act directly on the cable surface, which will have a certain impact on the measurement accuracy; 3) The measurement time is too long, and manual climbing and binding of sensors are required, which has low measurement efficiency and is accompanied by certain risks; 4) The measurement is difficult to carry out synchronously, and the measurement results can only reflect the comprehensive situation of the bridge in a certain period of time. It is difficult to evaluate the cable force health and safety status of the entire bridge at the same time.

[0004] In summary, in the prior art, in the process of cable damage identification and positioning, there are technical problems such as low efficiency and accuracy in obtaining the cable vibration mode, high risk, difficulty in achieving multi-point synchronization, and small coverage. Summary of the invention

[0005] In order to solve the above technical problems existing in the prior art, the embodiment of the present invention provides a method and device for identifying and locating cable damage based on millimeter wave radar. The technical solution is as follows:

[0006] On the one hand, a method for identifying and locating cable damage based on millimeter-wave radar is provided, the method comprising: vibrating a preset position of a target bridge cable so that the target bridge cable vibrates under a preset excitation force and a preset excitation frequency; based on the millimeter-wave radar, continuously sampling the vibration displacement signals of multiple monitoring points on the target bridge cable to obtain a sampled complex signal of each monitoring point; based on interference calculation of the sampled complex signal, obtaining a vibration time history curve corresponding to each monitoring point; performing discrete Fourier transform on the vibration time history curve to obtain the first N-order vibration frequencies and the first N-order vibration shapes corresponding to each monitoring point; N is a preset positive integer; comparing the first N-order vibration frequencies and the first N-order vibration shapes corresponding to each monitoring point with the first N-order vibration frequencies and the first N-order vibration shapes of the preset monitoring point, and judging whether the target bridge cable is damaged based on the comparison result; the preset monitoring point is the monitoring point sampled based on the millimeter-wave radar when the target bridge cable is in an undamaged state and subjected to vibration excitation; if so, locating the damage of the target bridge cable based on the vibration shape change of each monitoring point.

[0007] Optionally, it also includes: obtaining the first N vibration frequencies and the first N vibration modes of the preset monitoring points; including: performing vibration excitation at the preset position on the target bridge cable in an undamaged state, so that the target bridge cable in an undamaged state vibrates under the preset excitation force and the preset excitation frequency; based on millimeter wave radar, continuously sampling the vibration displacement signals of multiple preset monitoring points on the target bridge cable in an undamaged state, respectively, to obtain an undamaged sampled complex signal of each preset monitoring point; based on interference calculation of the undamaged sampled complex signal, obtaining an undamaged vibration time history curve corresponding to each preset monitoring point; performing discrete Fourier transform on the undamaged vibration time history curve to obtain the first N vibration frequencies and the first N vibration modes corresponding to each preset monitoring point.

[0008] Optionally, based on the interference calculation of the sampled complex signals, a vibration time history curve corresponding to each monitoring point is obtained, including: extracting the deformation phase based on the interference calculation of adjacent sampled complex signals; calculating the displacement deformation amount of each monitoring point based on the wavelength of the millimeter wave radar and the deformation phase to obtain the vibration time history curve.

[0009] Optionally, a discrete Fourier transform is performed on the vibration time history curve to obtain the first N vibration frequencies and the first N vibration modes corresponding to each monitoring point, including: performing a discrete Fourier transform on the vibration time history curve to obtain frequency domain eigenvalues; based on the frequency domain eigenvalues ​​and the motion characteristic equation, calculating the first N vibration frequencies and the first N vibration modes corresponding to each monitoring point.

[0010] Optionally, the first N-order vibration frequencies and the first N-order vibration modes corresponding to each monitoring point are compared with the first N-order vibration frequencies and the first N-order vibration modes of the preset monitoring point, and based on the comparison result, it is determined whether the target bridge cable is damaged, including: determining whether the difference between the first N-order vibration frequencies corresponding to each monitoring point and the first N-order vibration frequencies of the preset monitoring point is less than a preset frequency threshold, and the difference between the first N-order vibration modes corresponding to each monitoring point and the first N-order vibration modes of the preset monitoring point is less than a preset vibration mode threshold; if not, it is determined that the target bridge cable is damaged.

[0011] Optionally, based on the vibration mode change of each monitoring point, damage location is performed on the target bridge cable, including: respectively calculating the vibration mode change between each monitoring point and the corresponding preset monitoring point; and determining the position of the monitoring point with the largest vibration mode change as the damage position of the target bridge cable.

[0012] On the other hand, a cable damage identification and positioning device based on millimeter-wave radar is provided, comprising: an exciter, a millimeter-wave radar and an analysis module; wherein the exciter is used to perform vibration excitation on a preset position of a target bridge cable so that the target bridge cable vibrates under a preset excitation force and a preset excitation frequency; the millimeter-wave radar is used to continuously sample vibration displacement signals of multiple monitoring points on the target bridge cable, respectively, to obtain a sampled complex signal of each monitoring point; the analysis module is used to obtain a vibration time history curve corresponding to each monitoring point based on interference calculation of the sampled complex signal; the analysis module is also used to sample the ... The vibration time history curve is subjected to discrete Fourier transform to obtain the first N-order vibration frequencies and the first N-order vibration modes corresponding to each monitoring point; N is a preset positive integer; the analysis module is also used to compare the first N-order vibration frequencies and the first N-order vibration modes corresponding to each monitoring point with the first N-order vibration frequencies and the first N-order vibration modes of the preset monitoring point, and judge whether the target bridge cable is damaged based on the comparison result; the preset monitoring point is the monitoring point sampled by the millimeter wave radar when the target bridge cable is in an undamaged state and vibrates; if so, the damage location of the target bridge cable is performed based on the vibration mode change of each monitoring point.

[0013] Optionally, the millimeter wave radar is arranged below the target bridge cable.

[0014] Optionally, the analysis model is also used to: extract the deformation phase based on the interference calculation of adjacent sampled complex signals; calculate the displacement deformation amount of each monitoring point based on the wavelength of the millimeter wave radar and the deformation phase to obtain the vibration time history curve.

[0015] Optionally, the analysis module is further used to: perform discrete Fourier transform on the vibration time history curve to obtain frequency domain eigenvalues; and calculate the first N-order vibration frequencies and first N-order vibration modes corresponding to each monitoring point based on the frequency domain eigenvalues ​​and motion characteristic equations.

[0016] The beneficial effects brought about by the technical solution provided by the embodiment of the present invention include at least: combining millimeter-wave radar measurement technology with the vibration mode change method, improving the efficiency and accuracy of damage identification and positioning, and realizing cable damage identification and positioning efficiently, safely, with high precision, multi-point synchronization, and all-weather and all-day, saving labor costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. 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 creative work.

[0018] Figure 1 It is a flow chart of a cable damage identification and positioning method based on millimeter wave radar provided by an embodiment of the present invention;

[0019] Figure 2 is a schematic diagram of a vibration time history curve of a monitoring point provided by an embodiment of the present invention;

[0020] Figure 3 is a curve diagram of a frequency domain characteristic value provided by an embodiment of the present invention;

[0021] Figure 4 It is a schematic diagram of the first five vibration modes provided by an embodiment of the present invention;

[0022] Figure 5 It is a schematic diagram of a cable damage identification and positioning device based on millimeter wave radar provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is described below in conjunction with the accompanying drawings.

[0024] In the embodiments of the present invention, words such as "exemplarily" and "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "example" in the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of the word "example" is intended to present the concept in a specific way. In addition, in the embodiments of the present invention, the meaning expressed by "and / or" can be both, or it can be either of the two.

[0025] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0026] Embodiment 1

[0027] Figure 1 FIG. 1 is a flow chart of a method for identifying and locating cable damage based on millimeter wave radar according to an embodiment of the present invention. Figure 1 As shown, the method specifically comprises the following steps:

[0028] Step S102 : Vibration excitation is performed on a preset position of a target bridge cable, so that the target bridge cable vibrates at a preset excitation force and a preset excitation frequency.

[0029] Step S104: Based on the millimeter wave radar, the vibration displacement signals of multiple monitoring points on the target bridge cable are continuously sampled to obtain a sampled complex signal of each monitoring point.

[0030] Step S106, based on the interference calculation of the sampled complex signal, obtain the vibration time history curve corresponding to each monitoring point. Specifically, it includes the following steps:

[0031] Extract the deformation phase based on the interference calculation of adjacent sampled complex signals;

[0032] Based on the wavelength and deformation phase of the millimeter-wave radar, the displacement deformation of each monitoring point is calculated to obtain the vibration time history curve.

[0033] Step S108, performing discrete Fourier transform on the vibration time history curve to obtain the first N vibration frequencies and first N vibration modes corresponding to each monitoring point; N is a preset positive integer. Specifically, the steps include:

[0034] Perform discrete Fourier transform on the vibration time history curve to obtain the frequency domain eigenvalue;

[0035] Based on the frequency domain eigenvalues ​​and motion characteristic equations, the first N vibration frequencies and the first N vibration modes corresponding to each monitoring point are calculated.

[0036] Step S110, compare the first N-order vibration frequencies and first N-order vibration modes corresponding to each monitoring point with the first N-order vibration frequencies and first N-order vibration modes of the preset monitoring point, and judge whether the target bridge cable is damaged based on the comparison result; if so, locate the damage of the target bridge cable based on the vibration mode change of each monitoring point. The preset monitoring point is the monitoring point sampled by the millimeter wave radar when the target bridge cable is in an undamaged state and subjected to vibration excitation.

[0037] Specifically, it is determined whether the difference between the first N-order vibration frequencies corresponding to each monitoring point and the first N-order vibration frequencies of the preset monitoring point is less than the preset frequency threshold, and whether the difference between the first N-order vibration modes corresponding to each monitoring point and the first N-order vibration modes of the preset monitoring point is less than the preset vibration mode threshold;

[0038] If not, it is determined that the target bridge cable is damaged.

[0039] Calculate the vibration mode change between each monitoring point and the corresponding preset monitoring point respectively;

[0040] The monitoring point with the largest vibration mode change is determined as the damage location of the target bridge cable.

[0041] Specifically, the method provided in the embodiment of the present invention further includes: obtaining the first N-order vibration frequencies and the first N-order vibration modes of the preset monitoring points. Specifically, the method includes the following steps:

[0042] The target bridge cable in an undamaged state is subjected to vibration excitation at a preset position, so that the target bridge cable in an undamaged state vibrates at a preset excitation force and a preset excitation frequency;

[0043] Based on millimeter-wave radar, the vibration displacement signals of multiple preset monitoring points on the target bridge cable in an undamaged state are continuously sampled to obtain the undamaged sampling complex signal of each preset monitoring point;

[0044] Based on the interference calculation of the undamaged sampling complex signal, the undamaged vibration time history curve corresponding to each preset monitoring point is obtained;

[0045] The undamaged vibration time history curve is subjected to discrete Fourier transform to obtain the first N vibration frequencies and the first N vibration modes corresponding to each preset monitoring point.

[0046] Specifically, after the bridge is built, that is, before the cables are damaged, a vibration exciter is used to input a specific exciting force and exciting frequency into a specific position of the cables, so that the cables vibrate;

[0047] Then, the millimeter-wave radar is used to continuously sample the vibration displacement signals of multiple preset monitoring points (for example, ten monitoring points, and a long cable can measure twenty monitoring points). A series of observed phases and phase differences are obtained through continuous transmission and reflection, which are all planned into the interval [-π,π). When calculating the angle difference, it is necessary to determine the quadrant in which the angle is located. In order to avoid frequently determining the quadrant in which the angle is located, the conjugate multiplication of complex numbers is usually used to extract the interference phase, and the formula is:

[0048]

[0049] Where: S1 and S2 are adjacent sampled complex signals; A1 and A2 are the intensities of microwave vibration displacement signals of adjacent sampled complex signals; is the observed phase value; S IF is the interference phase; is the phase difference between the two deformation measurements.

[0050] Extracting deformation phase by interferometric calculation between adjacent sampling signals After obtaining the phase change, the displacement deformation is calculated using the following calculation formula:

[0051]

[0052] Where: d is the deformation in the direction of the radar line of sight; λ is the wavelength of the millimeter wave radar.

[0053] The curve of displacement deformation changing with time is the vibration time history curve, such as Figure 2 As shown, Figure 2 A schematic diagram of a vibration time history curve of a monitoring point provided according to an embodiment of the present invention. The static load test of a bridge usually requires testing the vertical deformation of the bridge perpendicular to the direction of the bridge body when static load is applied, that is, the deflection of the bridge. When the radar is placed directly below the bridge measuring point, the deformation variable d in the radar line of sight direction is the same as the deflection value of the bridge, and the deflection of the bridge can be monitored by this method.

[0054] Then the vibration time history curve of the cable is transformed by DFT (discrete Fourier transform), and the formula is:

[0055]

[0056] Where: X(k) is the kth complex number in the frequency domain, representing the frequency component of the signal; x(n) is the nth sample value in the time domain; N is the length of the signal; j is the imaginary unit, satisfying j2=-1; e is the base of the natural logarithm.

[0057] Figure 3 is a curve diagram of a frequency domain characteristic value provided according to an embodiment of the present invention. Figure 3 As shown, the time domain signal is converted into a frequency domain signal through DFT (discrete Fourier transform) to obtain the frequency domain eigenvalue, so as to calculate the first N-order vibration frequencies and spectrum characteristics of the measuring point, for example, the first 5-order vibration frequencies and spectrum characteristics; then it is brought into the motion characteristic equation to obtain the vibration mode corresponding to each order frequency and save it in the database, as shown in Figure 4 As shown, Figure 4 It is a schematic diagram of the first five vibration modes provided according to an embodiment of the present invention.

[0058] Specifically, the characteristic equation of motion is as follows:

[0059]

[0060] Where: m is the mass of the cable; c is the damping of the cable; k is the stiffness of the cable; ω i is the vibration frequency corresponding to the i-th vibration mode; φ i is the i-th order vibration mode function; φ i ' is φ i For the first derivative of x; φ i " is φ i The second derivative of x.

[0061] Then, when the bridge cable needs to be inspected, the same exciting force and exciting frequency are input into the same position of the cable using a vibration exciter to make the cable vibrate. The millimeter-wave radar is then used to measure the vibration displacement signals of multiple monitoring points at the same position (for example, ten points, or twenty points for a long cable), and the first five frequencies and vibration modes of the cable are fitted in the software system.

[0062] The cable is compared with the first five vibration modes and frequencies in the database. If there is a difference in one category, it can be determined that the cable is damaged.

[0063] If damage occurs, the vibration type change method is used to compare the vibration type information of multiple measurement points that have been measured before:

[0064] The 5th-order vibration difference of the first measuring point:

[0065]

[0066]

[0067]

[0068]

[0069]

[0070] The 5th-order vibration difference of the second measuring point:

[0071]

[0072]

[0073]

[0074]

[0075]

[0076] …

[0077] Compare the measuring point or two adjacent measuring points with the largest absolute value of the change in each order of vibration mode before and after, and lock the area with the largest change. This area is the specific location of the damage in the cable.

[0078] From the above description, it can be seen that the embodiment of the present invention provides a method for identifying and locating cable damage based on millimeter-wave radar, which uses millimeter-wave radar to obtain the vibration displacement signal of the bridge cable in real time, and then uses the vibration mode change method to use the obtained signal for identification and positioning. It can realize cable damage identification and positioning efficiently, safely, with high precision, multi-point synchronization and all-weather and all-day, saving labor costs and greatly improving the efficiency and accuracy of bridge cable damage identification and positioning.

[0079] Embodiment 2

[0080] Figure 5 FIG. 1 is a schematic diagram of a cable damage identification and positioning device based on millimeter wave radar according to an embodiment of the present invention. Figure 5 As shown, the device includes: a vibration exciter 1, a millimeter wave radar 2 and an analysis module 3. The millimeter wave radar 2 is arranged below the cable of the target bridge.

[0081] Specifically, the vibration exciter 1 is used to perform vibration excitation on a preset position of a target bridge cable, so that the target bridge cable vibrates at a preset exciting force and a preset exciting frequency.

[0082] The millimeter wave radar 2 is used to continuously sample the vibration displacement signals of multiple monitoring points on the target bridge cable to obtain a sampled complex signal of each monitoring point.

[0083] The analysis module 3 is used to obtain the vibration time history curve corresponding to each monitoring point based on the interference calculation of the sampled complex signal.

[0084] Specifically, based on the interference calculation of adjacent sampled complex signals, the deformation phase is extracted; based on the wavelength and deformation phase of the millimeter wave radar, the displacement deformation amount of each monitoring point is calculated to obtain the vibration time history curve.

[0085] The analysis module 3 is also used to perform discrete Fourier transform on the vibration time history curve to obtain the first N-order vibration frequencies and the first N-order vibration modes corresponding to each monitoring point; N is a preset positive integer.

[0086] Specifically, a discrete Fourier transform is performed on the vibration time history curve to obtain frequency domain eigenvalues; based on the frequency domain eigenvalues ​​and the motion characteristic equation, the first N-order vibration frequencies and the first N-order vibration modes corresponding to each monitoring point are calculated.

[0087] The analysis module 3 is also used to compare the first N vibration frequencies and the first N vibration modes corresponding to each monitoring point with the first N vibration frequencies and the first N vibration modes of the preset monitoring point, and judge whether the target bridge cable is damaged based on the comparison result; the preset monitoring point is the monitoring point sampled by the millimeter wave radar when the target bridge cable is in an undamaged state and subjected to vibration excitation; if so, the damage of the target bridge cable is located based on the change in the vibration mode of each monitoring point.

[0088] Specifically, it is determined whether the difference between the first N-order vibration frequencies corresponding to each monitoring point and the first N-order vibration frequencies of the preset monitoring point is less than the preset frequency threshold, and whether the difference between the first N-order vibration modes corresponding to each monitoring point and the first N-order vibration modes of the preset monitoring point is less than the preset vibration mode threshold;

[0089] If not, it is determined that the target bridge cable is damaged.

[0090] Calculate the vibration mode change between each monitoring point and the corresponding preset monitoring point respectively;

[0091] The monitoring point with the largest vibration mode change is determined as the damage location of the target bridge cable.

[0092] Specifically, the analysis module 3 is also used to: obtain the first N vibration frequencies and the first N vibration modes of the preset monitoring points. Specifically, the target bridge cable in an undamaged state is subjected to vibration excitation at a preset position, so that the target bridge cable in an undamaged state vibrates at a preset excitation force and a preset excitation frequency; based on the millimeter wave radar, the vibration displacement signals of multiple preset monitoring points on the target bridge cable in an undamaged state are continuously sampled respectively to obtain the undamaged sampled complex signal of each preset monitoring point; based on the interference calculation of the undamaged sampled complex signal, the undamaged vibration time history curve corresponding to each preset monitoring point is obtained; the undamaged vibration time history curve is subjected to discrete Fourier transform to obtain the first N vibration frequencies and the first N vibration modes corresponding to each preset monitoring point.

[0093] It should be understood that the memory in the embodiment of the present invention may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example and not limitation, many forms of random access memory (RAM) are available, such as static RAM (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0094] The above embodiments can be implemented in whole or in part by software, hardware (such as circuits), firmware or any other combination. When implemented by software, the above embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the process or function described in the embodiment of the present invention is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center by wired (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device such as a server or data center that contains one or more available media sets. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a tape), an optical medium (for example, a DVD), or a semiconductor medium. The semiconductor medium can be a solid-state hard disk.

[0095] It should be understood that in various embodiments of the present invention, the size of the serial numbers of the above-mentioned processes does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0096] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0097] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the above-described equipment, devices and units can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0098] In the several embodiments provided by the present invention, it should be understood that the disclosed devices, apparatuses and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0099] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0100] In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0101] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0102] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A cable damage identification and positioning method based on millimeter wave radar, characterized in that: The method comprises: Performing vibration excitation on a preset position of a target bridge cable so that the target bridge cable vibrates at a preset excitation force and a preset excitation frequency; Based on the millimeter wave radar, the vibration displacement signals of multiple monitoring points on the target bridge cable are continuously sampled to obtain a sampled complex signal of each monitoring point; Based on the interference calculation of the sampled complex signal, the vibration time history curve corresponding to each monitoring point is obtained, including: Extract the deformation phase based on the interference calculation of adjacent sampled complex signals; Based on the wavelength of the millimeter wave radar and the deformation phase, the displacement deformation amount of each monitoring point is calculated to obtain the vibration time history curve; Performing discrete Fourier transform on the vibration time history curve to obtain the first N-order vibration frequencies and the first N-order vibration modes corresponding to each monitoring point; N is a preset positive integer; Compare the first N-order vibration frequencies and the first N-order vibration modes corresponding to each monitoring point with the first N-order vibration frequencies and the first N-order vibration modes of the preset monitoring point, and judge whether the target bridge cable is damaged based on the comparison result; the preset monitoring point is the monitoring point sampled by the millimeter wave radar when the target bridge cable is in an undamaged state and subjected to vibration excitation; If yes, damage location is performed on the target bridge cable based on the vibration mode change of each monitoring point.

2. The method according to claim 1, characterized in that Also includes: Obtaining the first N vibration frequencies and the first N vibration modes of the preset monitoring point; including: Performing vibration excitation on the target bridge cable in an undamaged state at the preset position, so that the target bridge cable in an undamaged state vibrates at the preset excitation force and the preset excitation frequency; Based on the millimeter wave radar, the vibration displacement signals of multiple preset monitoring points on the target bridge cable in an undamaged state are continuously sampled to obtain an undamaged sampling complex signal of each preset monitoring point; Based on the interference calculation of the undamaged sampled complex signal, an undamaged vibration time history curve corresponding to each preset monitoring point is obtained; The undamaged vibration time history curve is subjected to discrete Fourier transform to obtain the first N-order vibration frequencies and the first N-order vibration modes corresponding to each preset monitoring point.

3. The method according to claim 1, characterized in that The vibration time history curve is subjected to discrete Fourier transform to obtain the first N-order vibration frequencies and the first N-order vibration modes corresponding to each monitoring point, including: Performing discrete Fourier transform on the vibration time history curve to obtain frequency domain eigenvalues; Based on the frequency domain eigenvalues ​​and the motion characteristic equation, the first N-order vibration frequencies and the first N-order vibration modes corresponding to each monitoring point are calculated.

4. The method according to claim 1, characterized in that: Compare the first N vibration frequencies and the first N vibration modes corresponding to each monitoring point with the first N vibration frequencies and the first N vibration modes of the preset monitoring point, and judge whether the target bridge cable is damaged based on the comparison result, including: Determine whether the difference between the first N-order vibration frequencies corresponding to each monitoring point and the first N-order vibration frequencies of the preset monitoring point is less than a preset frequency threshold, and whether the difference between the first N-order vibration modes corresponding to each monitoring point and the first N-order vibration modes of the preset monitoring point is less than a preset vibration mode threshold; If not, it is determined that the target bridge cable is damaged.

5. The method according to claim 1, characterized in that Based on the vibration mode change of each monitoring point, damage location of the target bridge cable is performed, including: Calculate the vibration mode change between each monitoring point and the corresponding preset monitoring point respectively; The monitoring point position with the largest vibration mode change is determined as the damage position of the target bridge cable.

6. A cable damage identification and positioning device based on millimeter wave radar, characterized in that: include: Exciter, millimeter wave radar and analysis module; among them, The vibration exciter is used to perform vibration excitation on a preset position of a target bridge cable, so that the target bridge cable vibrates at a preset excitation force and a preset excitation frequency; The millimeter wave radar is used to continuously sample the vibration displacement signals of multiple monitoring points on the target bridge cable to obtain a sampled complex signal of each monitoring point; The analysis module is used to obtain a vibration time history curve corresponding to each monitoring point based on the interference calculation of the sampled complex signal, including: Extract the deformation phase based on the interference calculation of adjacent sampled complex signals; Based on the wavelength of the millimeter wave radar and the deformation phase, the displacement deformation amount of each monitoring point is calculated to obtain the vibration time history curve; The analysis module is further used to perform discrete Fourier transform on the vibration time history curve to obtain the first N-order vibration frequencies and the first N-order vibration modes corresponding to each monitoring point; N is a preset positive integer; The analysis module is also used to compare the first N vibration frequencies and the first N vibration modes corresponding to each monitoring point with the first N vibration frequencies and the first N vibration modes of the preset monitoring point, and judge whether the target bridge cable is damaged based on the comparison result; the preset monitoring point is the monitoring point sampled by the millimeter wave radar when the target bridge cable is in an undamaged state and subjected to vibration excitation; if so, the damage location of the target bridge cable is performed based on the vibration mode change of each monitoring point.

7. The device according to claim 6, characterized in that The millimeter wave radar is arranged below the target bridge cable.

8. The device according to claim 6, characterized in that The analysis module is further used for: Performing discrete Fourier transform on the vibration time history curve to obtain frequency domain eigenvalues; Based on the frequency domain eigenvalues ​​and the motion characteristic equation, the first N-order vibration frequencies and the first N-order vibration modes corresponding to each monitoring point are calculated.

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