Cable-stayed bridge cable damage degree detection system and method

Abstract

The invention relates to a cable-stayed bridge cable damage degree detection system and method, and the system comprises an image data collection module which is used for collecting image data of an external protection layer of a cable; the magnetic flux leakage method detection module is used for acquiring a magnetic flux leakage signal of the inhaul cable; the sensing frequency acquisition module is used for acquiring the sensing frequency at any moment; the PC end is used for analyzing and processing the image data to obtain the PE damage area of the inhaul cable; performing data analysis on the magnetic flux leakage signal to obtain the damage amount of the inhaul cable, and meanwhile, obtaining a disease position; inputting the sensing frequency into a time-varying cable force sensing model to obtain the cable force of the inhaul cable; the time-varying cable force sensing model is obtained by combining a frequency equation and a back analysis characteristic function on the basis of an analysis model of influence factors; wherein the PC terminal is wirelessly connected with the image data acquisition module, the magnetic flux leakage method detection module and the sensing frequency acquisition module.

Description

Technical Field

[0001] The invention relates to the technical field of bridge stay cable detection, and in particular to a system and method for detecting damage degree of stay cables of a cable-stayed bridge. Background Art

[0002] There are many methods for detecting the degree of damage of cable-stayed bridges. For example, manual inspection is a method in which construction workers climb up the cables from bottom to top through safety devices. This method is labor-intensive and has potential safety hazards. Large detector inspection is to install the instrument on the cable and remotely control it from below. The machine transmits the degree of damage to the cable to the operator. The limitation of this method is that the weight of the machine will cause damage to the cable, and the inspection requires a specified time, which cannot reflect the degree of damage to the cable in real time. Therefore, there is a need for a cable measuring instrument with a small dead weight and the ability to reflect the degree of damage to the cable in real time. Summary of the invention

[0003] In order to solve the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a cable-stayed bridge cable damage degree detection system and method, which can detect the damage degree of the cable in real time.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] A cable-stayed bridge cable damage detection system, comprising:

[0006] An image data acquisition module, used for acquiring image data of the outer protective layer of the cable;

[0007] A magnetic flux leakage detection module, used for obtaining a magnetic flux leakage signal of the cable;

[0008] A perception frequency acquisition module is used to obtain the perception frequency at any time;

[0009] The PC end is used to analyze and process the image data to obtain the PE damage area of ​​the cable; perform data analysis on the magnetic leakage signal to obtain the damage amount of the cable and the location of the disease; input the perception frequency into the time-varying cable force perception model to obtain the cable force of the cable; the time-varying cable force perception model is obtained by combining the frequency equation and the inverse analysis characteristic function based on the analysis model of the influencing factors;

[0010] Wherein, the PC terminal is wirelessly connected to the image data acquisition module, the magnetic flux leakage detection module and the perception frequency acquisition module respectively.

[0011] Optionally, the image data acquisition module includes:

[0012] The image data acquisition unit is used to acquire the image data by acquiring a high-definition video of the outer protective layer of the cable in all directions based on a camera device.

[0013] Optionally, the magnetic flux leakage detection module includes:

[0014] The magnetic flux leakage detection unit uses an excitation sensor device to magnetize the cable to a saturation state and scans the cable axially. When the cable is damaged by defects, a magnetic flux leakage signal generated by a change in the magnetic field inside the cable is obtained.

[0015] Optionally, the perception frequency acquisition module includes:

[0016] The perception frequency acquisition unit is used to obtain acceleration using an acceleration sensor device, and to perform step-by-step deduction using an APES method to obtain the perception frequency at any time.

[0017] Optionally, the PC terminal includes:

[0018] An image data analysis unit, used to analyze and process the image data to obtain the PE damage area of ​​the cable;

[0019] A cable damage analysis unit, used to perform data analysis on a magnetic flux leakage signal generated by a change in the magnetic field inside the cable, to obtain the amount of damage to the cable;

[0020] Cable damage analysis and positioning, which is used to locate the damage position while obtaining the magnetic leakage signal using the encoding device;

[0021] The cable force acquisition unit is used to input the perception frequency into a time-varying cable force perception model to obtain the cable force of the cable; the time-varying cable force perception model is obtained based on an analysis model of influencing factors combined with a frequency equation and an inverse analysis characteristic function.

[0022] Optionally, the image data acquisition module, the magnetic flux leakage detection module and the perception frequency acquisition module are integrated and fixed to a lightweight carbon fiber frame structure, and the lightweight carbon fiber frame structure is equipped with a universal roller, through which the lightweight carbon fiber frame structure moves along the cable.

[0023] To achieve the above object, the present invention also provides a method for detecting the damage degree of cables of a cable-stayed bridge, comprising:

[0024] Collecting image data of the outer protective layer of the cable; analyzing and processing the image data to obtain the PE damage area of ​​the cable;

[0025] Acquire the magnetic leakage signal of the cable, perform data analysis on the magnetic leakage signal, obtain the damage amount of the cable, and simultaneously obtain the damage location;

[0026] Acquire the perception frequency at any time, input the perception frequency into a time-varying cable force perception model, and acquire the cable force of the cable;

[0027] The time-varying cable force perception model is obtained by combining a frequency equation and an inverse analysis characteristic function based on an analysis model of influencing factors.

[0028] The beneficial effects of the present invention are:

[0029] The present invention adopts carbon fiber materials and other scattered components, which can reduce the deadweight and thus reduce the damage to the cables, and can also better detect the degree of damage to the cables in real time, greatly improving the service life and safety of the bridge to a certain extent.

[0030] The image acquisition, magnetic leakage method and sensing frequency methods of the present invention obtain image data, magnetic leakage signal and sensing frequency, and further detect the cable through PC control and other subsequent commands given by the PC to obtain the surface damage of the cable, the damage and corrosion of the inside of the cable, and the size of the cable force, thereby completing the detection of the degree of cable damage. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0032] Figure 1 A schematic diagram of a cable-stayed bridge cable damage degree detection system according to an embodiment of the present invention;

[0033] Figure 2 A schematic diagram of a magnetic flux leakage detection device according to an embodiment of the present invention;

[0034] Figure 3 It is an overall device diagram of the instrument of an embodiment of the present invention;

[0035] Figure 4 FIG. 2 is a diagram of an instrument device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0038] like Figure 1 As shown, this embodiment discloses a cable-stayed bridge cable damage degree detection system, including: an image data acquisition module, used to collect image data of the outer protective layer of the cable; a magnetic leakage detection module, used to obtain the magnetic leakage signal of the cable; a perception frequency acquisition module, used to obtain the perception frequency at any time; a PC end, used to analyze and process the image data to obtain the PE damage area of ​​the cable; perform data analysis on the magnetic leakage signal to obtain the damage amount of the cable and the location of the disease; input the perception frequency into a time-varying cable force perception model to obtain the cable force of the cable; the time-varying cable force perception model is obtained by combining the frequency equation and the inverse analysis characteristic function based on the analysis model of the influencing factors; wherein the PC end is wirelessly connected to the image data acquisition module, the magnetic leakage detection module and the perception frequency acquisition module respectively.

[0039] Furthermore, the image data acquisition module includes:

[0040] The image data acquisition unit is used to collect all-round high-definition video of the outer protective layer of the cable based on a camera device to obtain image data.

[0041] Specifically, the camera will capture all-round high-definition video of the cable's external protective layer, through which the location of external damage can be clearly observed.

[0042] Furthermore, the magnetic flux leakage detection module includes:

[0043] The magnetic flux leakage detection unit uses an excitation sensor device to magnetize the cable to a saturation state and scans the cable axially. When the cable is damaged by defects, the magnetic flux leakage signal generated by the change in the magnetic field inside the cable is obtained.

[0044] Furthermore, the perception frequency acquisition module includes:

[0045] The perception frequency acquisition unit is used to obtain acceleration using an acceleration sensor device, and to perform step-by-step deduction using an APES method to obtain the perception frequency at any time.

[0046] Firstly, through the efficient recursive APES method, the time-varying frequency can be intelligently sensed in real time with arbitrary accuracy and time interval from the real-time monitored vibration signal of the cable, which can be used to obtain the cable force in the subsequent cable force sensing model.

[0047] Specifically, the machine starts working on the cable, and the excitation sensor also starts working, such as Figure 2. The working principle of the excitation sensor is mainly the leakage magnetic method. The excitation method detection device is mainly composed of Hall sensors, permanent magnets and other components. The measurement principle is that the armature, permanent magnet, and the measured cable form a magnetization circuit. When the excitation device magnetizes the cable to a saturated state and scans the cable axially relative to the cable, if the cable has defects such as broken wires or corrosion, it will cause the internal magnetic field of the cable to change. At this time, a leakage magnetic signal is generated, and the Hall sensor can detect the corresponding leakage magnetic signal. The amount of cable damage can be obtained by detecting and analyzing the leakage magnetic signal. At the same time, the encoder will also fix the damage, and the amount of damage will also be transmitted to the PC via a wireless signal.

[0048] The encoder captures the signal and frequency data, and then transmits these data to a device that can transmit and store signals. The magnetic flux leakage method and the frequency perception method in the present invention capture the signal and frequency data respectively, and then transmit these signals to the PC to locate the damage position.

[0049] The cable force is indirectly measured by a wireless acceleration sensor. When there is an acceleration sensor, the APES method can be used, combined with the block recursive calculation idea, to achieve real-time frequency perception at any time:

[0050] APES assumes that the collected signal is stationary. When processing non-stationary signals, we can resort to the adaptive extension of FT, i.e., short-time Fourier transform. At the same time, APES is extended to adapt to the changing signal spectrum while maintaining the advantage of high resolution. Therefore, a block-based recursive APES method is proposed for online spectrum estimation of time-varying signals, in which the size of the update block is adjustable to meet the real-time requirements of online calculations. In this way, real-time perception of frequency is obtained.

[0051] Based on the analytical model of influencing factors such as bending resistance and inclination angle, combined with the cable frequency equation and inverse analysis characteristic function, a high-precision cable force fitting method suitable for time-varying cable force perception is proposed, so as to obtain the cable force when the cable is perceived in real time and accurately. The wireless acceleration sensor is mounted on the robot, and the locking device is used to ensure that the robot and the cable are in an integrated state, so as to obtain the size of the cable force.

[0052] The analysis model includes: the structural model of beam theory or string vibration theory, clarifying the basic assumptions about the cable structure in the model, and deriving and constructing the cable frequency equation based on the principle of structural dynamics. For the tensioned cable, there is a certain relationship between its frequency and cable force. The inverse analysis characteristic function constructed based on the known cable force to find the frequency is introduced, the frequency is measured, and the cable force is inferred.

[0053] Furthermore, the PC terminal includes:

[0054] An image data analysis unit, used for analyzing and processing the image data to obtain the PE damage area of ​​the cable;

[0055] The cable damage analysis unit is used to analyze the leakage magnetic signal generated by the change of the internal magnetic field of the cable to obtain the damage amount of the cable;

[0056] Cable damage analysis and positioning, which is used to locate the damage position while obtaining the magnetic leakage signal using the encoding device;

[0057] The cable force acquisition unit is used to input the sensing frequency into the time-varying cable force sensing model to obtain the cable force of the cable; the time-varying cable force sensing model is obtained by combining the frequency equation and the inverse analysis characteristic function based on the analysis model of the influencing factors.

[0058] Specifically, computer remote processing, that is, host computer software design, a set of remote detection software developed on the labwindows platform can use computer terminals to wirelessly calculate cable tension, rust and broken wire data, and analyze and process the collected disease appearance image data through the platform's Vision Software.

[0059] Among them, the image data acquisition module, the magnetic flux leakage detection module and the perception frequency acquisition module are integrated and fixed to the lightweight carbon fiber frame structure. The lightweight carbon fiber frame structure is equipped with a universal roller, and the lightweight carbon fiber frame structure is moved along the cable through the universal roller.

[0060] The single-chip microcomputer system is like a small circuit system. When the PC side gives the machine the power to move up and down the cable, the single-chip microcomputer system will recognize the switch and energize the roller, and then the roller will drive the entire device to move on the cable.

[0061] The present embodiment also discloses a method for detecting the degree of damage of a cable of a cable-stayed bridge, comprising: collecting image data of an outer protective layer of the cable; analyzing and processing the image data to obtain a PE damage area of ​​the cable; obtaining a leakage magnetic signal of the cable, performing data analysis on the leakage magnetic signal to obtain the amount of damage to the cable, and simultaneously obtaining a location of the disease; obtaining a perception frequency at any time, inputting the perception frequency into a time-varying cable force perception model to obtain the cable force of the cable; wherein the time-varying cable force perception model is obtained by combining a frequency equation and an inverse analysis characteristic function based on an analysis model of influencing factors.

[0062] Specifically, first fix the machine on the cable and the host computer system will issue instructions and set the speed. According to the set speed, the machine will move back and forth on the cable, so there must be a control instrument operation system. The instrument is equipped with a serial communication circuit and a single-chip microcomputer system. The external computer can transmit and communicate with the serial communication circuit and the single-chip microcomputer system through a wireless module. It can be used to transmit instructions for the forward and reverse operation of the machine, and can also transmit real-time data of the stroke position, battery voltage and current. Specific method: Serial communication is a technology that uses serial communication protocols to perform asynchronous communication between computers and external devices. The external computer gives instructions to the serial communication circuit, and the communication circuit gives instructions to the ARM single-chip microcomputer. The ARM has its own navigation function and can therefore move back and forth.

[0063] like Figure 3-4 As shown, the present embodiment also discloses a sensor for detecting the degree of damage of a cable of a cable-stayed bridge, comprising: a lightweight carbon fiber frame structure for assembling other components; a universal roller for moving on the cable using a single-chip microcomputer and preventing the wheel body from deviating from the lock body; a camera for collecting image data of the outer protective layer of the cable; a magnetic leakage detection device for obtaining the magnetic leakage signal of the cable; a lithium battery for providing electrical energy; an encoder for locating the damaged position of the cable; a wireless acceleration sensor for measuring the acceleration of the universal roller; a WiFi transmitter for transmitting image data, magnetic leakage signals, damaged position and acceleration to a terminal for detecting the degree of damage on the cable surface, detecting the degree of damage and internal corrosion of the cable, measuring the cable force and locating the damaged position.

[0064] Specifically, the sensor includes: a lightweight carbon fiber frame structure, a universal roller, a camera, an excitation sensor, a lithium battery, an encoder, a wireless acceleration sensor, and WiFi. These devices work together to transmit the information to the Internet of Things for terminal processing. The device is installed on the cable of the cable-stayed bridge. Since the device uses carbon fiber materials and other scattered components, it can reduce its own weight and thus reduce the damage to the cable itself, and can also better detect the degree of damage to the cable in real time. To a certain extent, it greatly improves the service life and safety of the bridge.

[0065] The present embodiment discloses a sensor for detecting the degree of damage of the cable of a cable-stayed bridge, comprising: a lightweight carbon fiber frame structure: used for the assembly of other components. Universal roller: prevents the wheel body from deviating from the lock body and allows the machine to slide freely. Camera: used to observe the degree of damage on the surface of the cable. Excitation sensor: used to detect the internal corrosion and damage degree of the cable, including permanent magnets, Hall sensors, and armatures. Lithium battery: serves as the power supply of the machine to improve the endurance of the robot. Encoder: used to accurately locate the damaged position of the cable. Wireless acceleration sensor: used to measure the cable force. WiFi: transmits information to the terminal.

[0066] Furthermore, the magnetic flux leakage detection device includes: a Hall sensor, an armature is arranged above the Hall sensor, and a first permanent magnet and a second permanent magnet are arranged below the armature and on both sides of the Hall sensor.

[0067] The embodiments described above are only descriptions of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A cable-stayed bridge cable damage degree detection system, characterized in that: include: An image data acquisition module, used for acquiring image data of the outer protective layer of the cable; A magnetic flux leakage detection module, used for obtaining a magnetic flux leakage signal of the cable; A perception frequency acquisition module is used to obtain the perception frequency at any time; The PC end is used to analyze and process the image data to obtain the PE damage area of ​​the cable; perform data analysis on the magnetic leakage signal to obtain the damage amount of the cable and the location of the disease; input the perception frequency into the time-varying cable force perception model to obtain the cable force of the cable; the time-varying cable force perception model is obtained by combining the frequency equation and the inverse analysis characteristic function based on the analysis model of the influencing factors; Wherein, the PC terminal is wirelessly connected to the image data acquisition module, the magnetic flux leakage detection module and the perception frequency acquisition module respectively.

2. The cable-stayed bridge cable damage degree detection system according to claim 1 is characterized in that: The image data acquisition module comprises: The image data acquisition unit is used to acquire the image data by acquiring a high-definition video of the outer protective layer of the cable in all directions based on a camera device.

3. The cable-stayed bridge cable damage degree detection system according to claim 1, characterized in that: The magnetic flux leakage detection module comprises: The magnetic flux leakage detection unit uses an excitation sensor device to magnetize the cable to a saturation state and scans the cable axially. When the cable is damaged by defects, a magnetic flux leakage signal generated by a change in the magnetic field inside the cable is obtained.

4. The cable-stayed bridge cable damage degree detection system according to claim 1, characterized in that: The perception frequency acquisition module includes: The perception frequency acquisition unit is used to obtain acceleration using an acceleration sensor device, and to perform step-by-step deduction using an APES method to obtain the perception frequency at any time.

5. The cable-stayed bridge cable damage degree detection system according to claim 3, characterized in that: The PC terminal includes: An image data analysis unit, used to analyze and process the image data to obtain the PE damage area of ​​the cable; A cable damage analysis unit, used to perform data analysis on a magnetic flux leakage signal generated by a change in the magnetic field inside the cable, to obtain the amount of damage to the cable; Cable damage analysis and positioning, which is used to locate the damage position while obtaining the magnetic leakage signal using the encoding device; The cable force acquisition unit is used to input the perception frequency into a time-varying cable force perception model to obtain the cable force of the cable; the time-varying cable force perception model is obtained based on an analysis model of influencing factors combined with a frequency equation and an inverse analysis characteristic function.

6. The cable-stayed bridge cable damage degree detection system according to any one of claims 1 to 5, characterized in that: The image data acquisition module, the magnetic flux leakage detection module and the perception frequency acquisition module are integrated and fixed to a light carbon fiber frame structure. The light carbon fiber frame structure is installed with a universal roller, and the light carbon fiber frame structure is moved along the cable through the universal roller.

7. A method for detecting the damage degree of cables of a cable-stayed bridge, using the detection system according to any one of claims 1 to 6 for detection, characterized in that: include: Collect image data of the outer protective layer of the cable; Analyzing and processing the image data to obtain the PE damage area of ​​the cable; Acquire the magnetic leakage signal of the cable, perform data analysis on the magnetic leakage signal, obtain the damage amount of the cable, and simultaneously obtain the damage location; Acquire the perception frequency at any time, input the perception frequency into a time-varying cable force perception model, and acquire the cable force of the cable; The time-varying cable force perception model is obtained by combining a frequency equation and an inverse analysis characteristic function based on an analysis model of influencing factors.

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