Intelligent scanning robot for weld fatigue cracks of large-span steel bridge deck
By integrating the TMR phased array detection module with an intelligent scanning robot, efficient, non-contact, and high-precision detection of fatigue cracks in weld seams of long-span steel bridge decks has been achieved. This solves the problems of insufficient identification and quantification in existing technologies, and improves detection efficiency and adaptability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-24
- Publication Date
- 2026-03-31
AI Technical Summary
Existing non-destructive testing methods are insufficient in terms of early identification, accurate quantification, and adaptability to complex environments of fatigue cracks in welded seams of long-span steel bridge decks, making it difficult to meet the needs for rapid screening and preventive maintenance of fatigue damage throughout the entire life cycle of bridges.
A TMR phased array detection module is adopted, which is combined with a ferrite core and an excitation coil to form a high-sensitivity sensor array probe. By integrating pulse leakage magnetic field detection technology with an intelligent scanning robot, continuous scanning and real-time data processing of the weld area can be achieved to identify the location and size of fatigue cracks.
It enables high-speed, precise location and quantitative assessment of fatigue cracks in weld areas, improving detection efficiency, meeting the needs of bridge maintenance throughout its entire life cycle, and solving the problems of insufficient response to micro-cracks and limited identification of internal defects.
Smart Images
Figure CN121762672A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of non-destructive testing technology for fatigue cracks in long-span steel bridges, and particularly to an intelligent scanning robot for fatigue cracks in welded seams of long-span steel bridge decks. Background Technology
[0002] Long-span steel bridges are subjected to cyclical vehicle loads over extended periods during operation, which can easily lead to fatigue cracks and other damage in the welded areas connecting the top plate and longitudinal ribs. The development of fatigue cracks significantly weakens the structure's load-bearing capacity and durability, and in extreme cases, may even trigger serious engineering accidents, jeopardizing the overall safety of the bridge.
[0003] Currently, common non-destructive testing methods for fatigue cracks in steel structure bridges mainly include ultrasonic testing, eddy current testing, magnetic particle testing, and visual inspection. Among them, ultrasonic testing can effectively identify internal defects in welds, but it still faces challenges in accurately quantifying crack size; eddy current testing has high sensitivity to surface cracks in welds, but its ability to detect internal or near-surface cracks is relatively limited; magnetic particle testing is highly effective in identifying surface cracks, but it is difficult to effectively detect tiny cracks inside or near the surface of welds; visual inspection can provide a visual image of the weld surface, but its accuracy in assessing crack size is low.
[0004] It is evident that existing non-destructive testing methods still have significant shortcomings in early identification, accurate quantification, and adaptability to complex environments of fatigue cracks in welds of long-span steel bridge decks, making it difficult to meet the urgent need for rapid screening and preventive maintenance of fatigue damage throughout the entire life cycle of bridges. Therefore, there is an urgent need to develop a new testing technology to achieve efficient, non-contact, and high-precision automatic detection of weld fatigue cracks, while also being able to adapt to the complex spatial environment at the bottom of bridges. Summary of the Invention
[0005] This invention provides an intelligent robot for inspecting fatigue cracks in weld seams of long-span steel bridge decks, which can effectively solve the problems in the background art.
[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A smart robot for inspecting fatigue cracks in weld seams of long-span steel bridge decks includes: The mobile cart serves as a mobile carrier; The TMR phased array detection module includes a ferrite core, an excitation coil, and a sensor array probe composed of multiple TMR sensors. The ferrite core is used to adsorb and fix the TMR phased array detection module near the weld joint between the bottom of the top plate of the steel bridge deck and the longitudinal rib. The excitation coil is used to apply a pulse excitation signal to the weld area to form a uniform magnetic field. The sensor array probe is used to collect the abnormal leakage magnetic field signal caused by fatigue cracks in the weld area. The motion control module is electrically connected to the traveling trolley and is used to control the traveling trolley to move back and forth along the extension direction of the longitudinal rib weld seam, so as to drive the TMR phased array detection module to continuously scan the entire weld seam area. The data processing module is electrically connected to the TMR phased array detection module and the motion control module. It is used to process the leakage magnetic anomaly signal transmitted by the sensor array probe and identify the location and size of the weld fatigue crack based on the processed signal. An external power supply module is used to provide operating power to each module; When the excitation coil generates a uniform magnetic field in the weld area, if there is a fatigue crack in the weld, a magnetic leakage abnormal signal will be generated. The sensor array probe senses the magnetic leakage abnormal signal and transmits it to the data processing module, which then completes the identification and output of crack parameters.
[0007] Furthermore, the traveling trolley includes a moving body and two sets of rollers disposed at the bottom of the moving body and symmetrically distributed relative to the center line of the weld. The TMR phased array detection module, data processing module, and motion control module are all located in the internal cavity of the mobile body, and the motion control module and the data processing module are integrated and deployed on the same circuit board.
[0008] Furthermore, the ferrite core has a gantry frame structure, the crossbeams of the gantry frame structure are arranged along the length of the weld, and the excitation coil is uniformly wound on the crossbeams of the ferrite core; The sensor array probe is positioned directly below the excitation coil, with its detection end face facing the weld area of the steel bridge deck.
[0009] Furthermore, the sensor array probe consists of nine TMR sensors, used to detect the horizontal component of the leakage magnetic field in the region above the crack, and convert the horizontal component signal into an electrical signal and output it to the data processing module.
[0010] Furthermore, it also includes a buzzer electrically connected to the data processing module; The buzzer is used to receive the alarm trigger signal output by the data processing module and perform an audible and visual alarm when the data processing module identifies the abnormal magnetic leakage signal caused by fatigue cracks in the weld area. When the data processing module determines that there is fatigue crack damage in the weld based on the abnormal leakage magnetic field signal, it simultaneously sends a pause command to the motion control module to control the traveling trolley to stop moving.
[0011] Furthermore, it also includes a storage module electrically connected to the data processing module; The storage module is used to record in real time the location, size, and corresponding detection timestamp information of weld fatigue cracks output by the data processing module.
[0012] Furthermore, the pulse excitation signal applied to the excitation coil in the TMR phased array detection module has an excitation frequency of 50Hz and a signal duty cycle of 50%.
[0013] Furthermore, the data processing module integrates an AD converter, a preamplifier, and a bandpass filter circuit that are electrically connected in sequence.
[0014] Furthermore, the motion control module includes a control circuit, a drive motor, a Bluetooth communication unit, and a handheld remote control device; The drive motor is connected to the wheel axle of the walking trolley to provide power; The control circuit and the data processing module achieve real-time data interaction through a bus. The Bluetooth communication unit establishes a wireless communication link between the control circuit and the handheld remote control device. The handheld remote control device sends control commands to the walking vehicle through the control circuit.
[0015] Furthermore, the motion control module integrates path memory and automatic reset functions; The path memory function is used to dynamically record the complete detection travel path of the traveling trolley along the longitudinal rib weld. The automatic reset function is used to control the traveling trolley to return to the starting position along the detected travel path at a return speed higher than the detection speed.
[0016] The technical solution of this invention can achieve the following technical effects: By integrating the pulse magnetic flux leakage detection system with an intelligent scanning robot, defect identification and continuous scanning of the entire weld area can be achieved. Combining automated scanning and real-time data processing technology, it can achieve high-speed, accurate positioning and quantitative assessment of fatigue cracks in the weld area, and significantly improve detection efficiency. This provides an effective solution for fatigue damage detection of welds in steel structure bridges, while also meeting the urgent needs of bridge maintenance throughout its entire life cycle.
[0017] A sensor array probe consisting of multiple TMR sensors, combined with a magnetic field control design of ferrite core and excitation coil, forms a highly sensitive TMR phased array detection module. The sensitivity to magnetic field changes is improved by an order of magnitude compared with traditional magnetic particle detection, and it can accurately capture the weak leakage magnetic signals in the crack initiation stage. This solves the problems of insufficient response to micro-cracks and limitations in the identification of internal defects.
[0018] Phased array technology acquires signals synchronously through multiple sensors, and with the precise application of pulse excitation signals, it can not only effectively distinguish noise signals from crack leakage magnetic signals, but also fully acquire the spatial distribution characteristics of crack leakage magnetic signals, thus achieving precise location of crack spatial distribution. The data processing module, through feature extraction algorithms, establishes a quantitative correlation between the peak value, amplitude, and waveform changes of the leakage magnetic signal and the crack size, ultimately achieving precise output of crack location and size, thus overcoming the shortcomings of ultrasonic detection in quantification and visual detection in low accuracy. Attached Figure Description
[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0020] Figure 1 This is a schematic diagram showing the installation position of the weld between the top plate and the longitudinal rib of the traveling trolley. Figure 2 This is a schematic diagram showing the position of the sensor array probes; Figure 3 A schematic diagram showing the arrangement of multiple TMR sensors; Figure 4 This is a schematic diagram showing the arrangement of the ferrite core and excitation coil inside the traveling trolley.
[0021] Reference numerals: 1a, top plate; 2a, longitudinal rib; 1, traveling trolley; 11, moving body; 12, roller assembly; 2, ferrite core; 3, excitation coil; 4, TMR sensor; 5, drive motor. Detailed Implementation
[0022] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.
[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.
[0024] In this application, the full English name for tunneling magnetoresistance is Tunneling Magnetoresistance, and its standard abbreviation is TMR. All subsequent technical descriptions, component names, and functional specifications involving tunneling magnetoresistance will uniformly use the abbreviation TMR, such as TMR sensor, TMR phased array detection module, etc., to replace the full descriptions of tunneling magnetoresistance sensor and tunneling magnetoresistance phased array detection module.
[0025] like Figures 1-4 As shown, this application provides an intelligent robot for inspecting fatigue cracks in weld seams of long-span steel bridge decks, comprising: The mobile vehicle 1 serves as a mobile carrier; The TMR phased array detection module includes a ferrite core 2, an excitation coil 3, and a sensor array probe composed of multiple TMR sensors 4. The ferrite core 2 is used to adsorb and fix the TMR phased array detection module near the weld joint between the bottom of the top plate 1a of the steel bridge deck and the longitudinal rib 2a. The excitation coil 3 is used to apply a pulse excitation signal to the weld area to form a uniform magnetic field. The sensor array probe is used to collect the leakage magnetic abnormality signal generated by fatigue cracks in the weld area. The TMR phased array detection module has high sensitivity, excellent linearity, and wide dynamic range, which can effectively capture weak magnetic field signals, thereby realizing rapid scanning and defect identification of the weld area.
[0026] The motion control module is electrically connected to the traveling trolley 1 and is used to control the traveling trolley 1 to move back and forth along the extension direction of the longitudinal rib 2a weld seam, so as to drive the TMR phased array detection module to realize continuous scanning of the entire weld seam area. The data processing module, which is electrically connected to the TMR phased array detection module and the motion control module, is used to process the leakage magnetic anomaly signal transmitted by the sensor array probe and identify the location and size of the weld fatigue crack based on the processed signal. An external power supply module is used to provide working power for each module. The external power supply module provides a stable 36V DC power supply and is connected to the walking car 1 through wires to ensure the normal operation of the robot's various functional modules.
[0027] When the excitation coil 3 excites a uniform magnetic field in the weld area, if there is a fatigue crack in the weld, a leakage magnetic abnormality signal will be generated. The sensor array probe senses the leakage magnetic abnormality signal and transmits it to the data processing module, which then completes the identification and output of the crack parameters.
[0028] Pulsed magnetic flux leakage (PMFL) is an electromagnetic non-destructive testing method that uses pulse signals as the excitation source. Due to the rich frequency components in the pulse excitation signal, this technology exhibits higher detection sensitivity and adaptability for ferromagnetic materials with a certain thickness and complex structure. As a detection technology based on the principle of magnetic flux leakage, it mainly targets the leakage magnetic field on and near the surface of ferromagnetic materials. It not only effectively overcomes the lift-off effect interference caused by the anti-corrosion coating on the surface of steel bridge decks, improving the accuracy of the test results, but also avoids the problems of ultrasonic testing relying on coupling agents and eddy current testing having stringent surface condition requirements due to the fact that the detection module has no physical contact with the weld.
[0029] By integrating the pulse magnetic flux leakage detection system with an intelligent scanning robot, defect identification and continuous scanning of the entire weld area can be achieved. Combining automated scanning and real-time data processing technology, it can achieve high-speed, accurate positioning and quantitative assessment of fatigue cracks in the weld area, and significantly improve detection efficiency. This provides an effective solution for fatigue damage detection of welds in steel structure bridges, while also meeting the urgent needs of bridge maintenance throughout its entire life cycle.
[0030] Specifically, before testing, the sensor array probe is installed directly below the ferrite core 2, near the bottom of the top plate 1a, and at a certain lifting distance. The data processing module and motion control module adopt an integrated design and are deployed on the same circuit board, located above the sensor array probe. All modules are installed on the remote-controlled vehicle. The external power supply is turned on to power all modules. The power supply is responsible for providing a stable 36V DC power. After powering on, a pulse signal is introduced into the excitation coil 3. The ferrite core 2 generates a magnetic force to firmly attach the intelligent scanning robot to the bottom of the top plate 1a of the steel bridge panel, near the weld seam of the longitudinal rib 2a. At the same time, a uniform magnetic field is generated in the top plate 1a and the longitudinal rib 2a. The TMR phased array detection module automatically starts working after power-on; the TMR array sensor begins detecting the weld leakage magnetic field; the data processing module converts the detected analog signal into a digital signal, and after amplification and filtering, obtains the horizontal component intensity of the leakage magnetic field flux of the weld in the detection area; the motion control module sets the robot's running direction and speed before scanning, and sends a "start" signal to the intelligent scanning robot via a handheld Bluetooth remote control device, and the scanning vehicle moves forward according to the set direction and speed. When the data processing module receives a leakage magnetic field signal that is much greater than the threshold, the scanning vehicle pauses for 5-10 seconds, the buzzer alarms to remind the inspection personnel, and at the same time, it stores and records key information such as the location of the area, the horizontal component of the leakage magnetic field flux, and the current time.
[0031] A sensor array probe consisting of multiple TMR sensors 4 is adopted, and a magnetic field control design of ferrite core 2 and excitation coil 3 is combined to form a high-sensitivity TMR phased array detection module. The sensitivity to magnetic field changes is improved by an order of magnitude compared with traditional magnetic particle detection, which can accurately capture the weak leakage magnetic signal in the crack initiation stage. It solves the problems of insufficient response to micro-cracks and limited identification of internal defects.
[0032] Phased array technology acquires signals synchronously through multiple sensors, and with the precise application of pulse excitation signals, it can not only effectively distinguish noise signals from crack leakage magnetic signals, but also fully acquire the spatial distribution characteristics of crack leakage magnetic signals, thus achieving precise location of crack spatial distribution. The data processing module, through feature extraction algorithms, establishes a quantitative correlation between the peak value, amplitude, and waveform changes of the leakage magnetic signal and the crack size, ultimately achieving precise output of crack location and size, thus overcoming the shortcomings of ultrasonic detection in quantification and visual detection in low accuracy.
[0033] In a preferred embodiment, the traveling trolley 1 includes a moving body 11 and two roller sets 12 disposed at the bottom of the moving body 11 and symmetrically distributed relative to the center line of the weld; this enables the traveling trolley 1 to form a clamping traveling structure based on the weld, which can effectively offset the risk of displacement caused by bridge vibration or uneven surface, and ensure that the TMR phased array detection module is always aligned with the weld area.
[0034] The TMR phased array detection module, data processing module, and motion control module are all located in the internal cavity of the mobile body 11, making the overall structure of the robot more compact and allowing it to flexibly move through the narrow gap formed by the steel bridge panel and the longitudinal rib 2a. Furthermore, the motion control module and the data processing module are integrated and deployed on the same circuit board.
[0035] When the data processing module detects a crack, it can instantly send a pause command to the motion control module to ensure that the traveling trolley 1 stops precisely at the crack location, avoiding misalignment between the alarm position and the actual crack due to delay. At the same time, the trolley position, speed and other information of the motion control module can be fed back to the data processing module in real time, so that the crack location and the scanning trajectory are accurately matched, improving the positioning accuracy.
[0036] In this invention, the ferrite core 2 has a gantry frame structure, and the crossbeams of the gantry frame structure are arranged along the length of the weld. The excitation coil 3 is evenly wound on the crossbeams of the ferrite core 2. The sensor array probe is set directly below the excitation coil 3, and its detection end face is set directly opposite the weld area of the steel bridge deck.
[0037] The gantry-type magnetic core provides a stable magnetic conduction path. Its frame structure confines the magnetic field generated by the excitation coil 3 within the weld area and its surrounding region, reducing the diffusion of the magnetic field to non-detection areas and improving magnetic field utilization. Furthermore, the excitation coil 3 is wound around the crossbeam of the ferrite core 2. Combined with the magnetic conduction of the core, this forms a uniformly wide magnetic field coverage band on the weld surface, ensuring uniform coverage along the weld extension direction and providing a uniform magnetic field environment for the stable generation of crack leakage magnetic signals. Simultaneously, the sensor array probe's orientation directly facing the weld allows for precise capture of leakage magnetic signals at the crack location, achieving a complete closed-loop structure of magnetic field generation, path constraint, and signal reception. This collaborative design significantly improves magnetic field utilization and signal capture efficiency, enabling the sensor array probe to more stably sense weak leakage magnetic signals caused by minute cracks, providing a reliable guarantee for accurate early crack identification.
[0038] As a preferred embodiment of the above, the sensor array probe consists of nine TMR sensors 4, which are used to detect the horizontal component of the leakage magnetic field in the region above the crack, and convert the horizontal component signal into an electrical signal and output it to the data processing module.
[0039] Specifically, the nine TMR sensors 4 are arranged in a 3-row, 3-column configuration, forming an effective detection width that perfectly matches the width of the weld connecting the top plate 1a and the longitudinal rib 2a of the steel bridge deck. This enables a comprehensive, blind-spot-free scan of the weld area. In addition, the sensor spacing is precisely matched to capture the magnetic field abrupt change signal at the crack tip, avoiding the missed detection of tiny cracks due to excessively large sensor spacing.
[0040] In an ideal, crack-free weld, the magnetic field distribution within the detection area is uniform and stable. The component of magnetic flux density along the x-direction, parallel to the weld's extension direction, exhibits a balanced distribution. At this point, the internal magnetic field of the material is well-closed, and the magnetic field strength leaking to the outside is extremely weak. However, when defects such as fatigue cracks exist in the weld, the permeability of the steel at the crack location undergoes a drastic change, disrupting the uniform closed path of the magnetic field. This causes some of the magnetic field to fail to continue propagating within the material and instead leaks into the surrounding space, forming a leakage magnetic field. During this process, the distribution of the x-direction component of the magnetic flux density exhibits significant characteristic changes: the intensity of this component decreases markedly on both sides of the crack body; conversely, at the top and bottom tips of the crack, the x-direction component of the magnetic flux density shows a local increase, creating a stark contrast with the defect-free area. By extracting and analyzing this characteristic parameter change in the leakage magnetic field signal through the data processing module, a correlation model between the leakage magnetic field signal and the crack's geometric parameters can be established, thereby enabling precise quantitative assessment of the crack's location, depth, and length.
[0041] In a preferred embodiment of the present invention, the intelligent scanning robot further includes a buzzer electrically connected to the data processing module; the buzzer is used to receive an alarm trigger signal output by the data processing module and perform an audible and visual alarm when the data processing module identifies an abnormal magnetic leakage signal caused by fatigue cracks in the weld area. When the data processing module determines that there is fatigue crack damage in the weld based on the abnormal leakage magnetic signal, it simultaneously sends a pause command to the motion control module to control the traveling trolley 1 to stop moving.
[0042] The buzzer triggers an alarm the moment a crack is detected. Combined with a 15-10 second pause in the traveling trolley's movement, this allows inspectors to immediately mark or preliminarily assess the crack location, reducing the rate of missed crack detections. Simultaneously, the strong alertness of the audible and visual alarm effectively prevents operators from missing crucial inspection results due to distraction, further enhancing the reliability of the inspection work. After the alarm is triggered, the motion control module receives a continuation command from the data processing module, controlling the traveling trolley 1 to resume its scanning movement along the weld seam.
[0043] As a preferred embodiment of the above, the intelligent scanning robot also includes a storage module electrically connected to the data processing module; the storage module is used to record in real time the location, size and corresponding detection timestamp information of the weld fatigue crack output by the data processing module; the walking trolley 1 is provided with a USB data interface, which is communicatively connected to the storage module.
[0044] The crack detection information recorded in the storage module can be exported to external devices such as external computers and portable hard drives via the USB interface. This allows inspectors to accurately calculate the crack propagation rate by using data exported multiple times, thereby predicting the service risk of cracks and providing data support for preventive maintenance of bridges. This avoids blind maintenance decisions due to a lack of historical data. At the same time, the traceability of the data also provides a basis for the review of inspection results and the determination of responsibility.
[0045] As a preferred option, the pulse excitation signal applied by the excitation coil 3 in the TMR phased array detection module has an excitation frequency of 50Hz and a signal duty cycle of 50%.
[0046] Under a 50Hz alternating magnetic field, the permeability of the long-span steel bridge deck is within its optimal range, enabling rapid response to magnetic field changes and the formation of uniform magnetization. Simultaneously, the 50% duty cycle ensures symmetrical rise and fall edges of the magnetic field during the excitation and demagnetization cycles of the excitation coil 3, avoiding insufficient magnetization caused by signal asymmetry. Furthermore, the 50Hz excitation frequency improves the uniformity of the magnetic field in the weld area, controlling the fluctuation range of magnetic field strength and providing a stable magnetic field foundation for accurately capturing crack leakage magnetic signals.
[0047] Preferably, the data processing module integrates an AD converter, a preamplifier, and a bandpass filter circuit that are electrically connected in sequence.
[0048] The AD converter converts all the analog leakage magnetic field signals detected by the TMR array sensor into digital signals; then the signal is amplified by the preamplifier circuit, and then the noise outside a specific frequency band is suppressed by the bandpass filter circuit to suppress the noise of the weak leakage magnetic field signal collected by the sensor array; finally, clear and identifiable leakage magnetic field signal features are extracted.
[0049] Preferably, the motion control module includes a control circuit, a drive motor 5, a Bluetooth communication unit, and a handheld remote control device; the drive motor 5 is connected to the wheel axle of the walking trolley 1 to provide power; the control circuit and the data processing module realize real-time data interaction through a bus, the Bluetooth communication unit establishes a wireless communication link between the control circuit and the handheld remote control device, and the handheld remote control device sends control commands to the walking trolley 1 through the control circuit.
[0050] The motion control module has a reserved wireless communication interface, forming a two-way data interaction capability: on the one hand, it can receive remote control commands, and on the other hand, it can synchronously feed back the real-time position information of the walking trolley 1 to the data processing module. Through the precise correlation between position data and crack detection signals, the crack information and the detection position are matched one by one, providing a reliable basis for subsequent crack location and tracing.
[0051] In terms of remote control operation, the handheld remote control device adopts an intuitive graphical user interface, integrating start, stop, forward, backward, and quick reset function buttons. The handheld remote control device establishes a stable connection with the scanning robot via Bluetooth communication protocol. This connection method has strong anti-interference capabilities and can meet the communication needs in the complex environment under bridges. The robot's built-in control circuit serves as the core control hub, capable of parsing the commands issued by the handheld remote control device in real time and precisely adjusting the rotation direction and speed of the drive motor 5 accordingly. This enables precise control of the robot's forward, backward, acceleration, and deceleration movements, ensuring a flexible and controllable scanning process.
[0052] In a preferred embodiment of the present invention, the motion control module integrates a path memory function and an automatic reset function; the path memory function is used to dynamically record the complete detection travel path of the traveling trolley 1 along the weld of the longitudinal rib 2a; the automatic reset function is used to control the traveling trolley 1 to return to the starting position along the detected travel path at a return speed higher than the detection speed.
[0053] During the inspection process, the path memory function collects the displacement data of the traveling trolley 1 in real time through the absolute encoder, dynamically recording the complete inspection travel path of the traveling trolley 1 along the longitudinal rib 2a weld. When the traveling trolley 1 completes the scanning operation of the entire longitudinal rib 2a at the set inspection speed and travels to the position of the transverse diaphragm, the automatic reset program is triggered. The motion control module calls the inspection travel path pre-stored by the path memory function and controls the traveling trolley 1 to travel in reverse at a speed higher than the inspection speed along the original path at a constant speed. Through displacement data closed-loop calibration, the trolley 1 is accurately reset to the inspection start position recorded by the data processing module. Then the motion control module enters the standby state to wait for the next inspection command, eliminating the cumbersome process of manual operation for the return trip, greatly shortening the equipment return waiting time, and significantly improving the overall operation efficiency of continuous inspection of multiple weld sections.
[0054] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of the application as defined herein, and are to be considered as covering any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Thus, if such modifications and modifications fall within the scope of this application and its equivalents, this application intends to include such modifications and modifications.
Claims
1. An intelligent robot for inspecting fatigue cracks in weld seams of large-span steel bridge decks, characterized in that, include: A mobile vehicle; The TMR phased array detection module includes a ferrite core, an excitation coil, and a sensor array probe composed of multiple TMR sensors. The ferrite core is used to adsorb and fix the TMR phased array detection module near the weld joint between the bottom of the top plate of the steel bridge deck and the longitudinal rib. The excitation coil is used to apply a pulse excitation signal to the weld area to form a uniform magnetic field. The sensor array probe is used to collect the abnormal leakage magnetic field signal caused by fatigue cracks in the weld area. The motion control module is electrically connected to the traveling trolley and is used to control the traveling trolley to move back and forth along the extension direction of the longitudinal rib weld seam, so as to drive the TMR phased array detection module to continuously scan the entire weld seam area. The data processing module is electrically connected to the TMR phased array detection module and the motion control module. It is used to process the leakage magnetic anomaly signal transmitted by the sensor array probe and identify the location and size of the weld fatigue crack based on the processed signal. An external power supply module is used to provide operating power to each module; When the excitation coil generates a uniform magnetic field in the weld area, if there is a fatigue crack in the weld, a magnetic leakage abnormal signal will be generated. The sensor array probe senses the magnetic leakage abnormal signal and transmits it to the data processing module, which then completes the identification and output of crack parameters.
2. The intelligent robot for inspecting fatigue cracks in weld seams of large-span steel bridge decks according to claim 1, characterized in that, The traveling trolley includes a mobile body and two sets of rollers arranged at the bottom of the mobile body and symmetrically distributed relative to the center line of the weld. The TMR phased array detection module, data processing module, and motion control module are all located in the internal cavity of the mobile body, and the motion control module and the data processing module are integrated and deployed on the same circuit board.
3. The intelligent robot for inspecting fatigue cracks in weld seams of large-span steel bridge decks according to claim 1, characterized in that, The ferrite core has a gantry frame structure, and the crossbeams of the gantry frame structure are arranged along the length of the weld. The excitation coil is evenly wound on the crossbeams of the ferrite core. The sensor array probe is positioned directly below the excitation coil, with its detection end face facing the weld area of the steel bridge deck.
4. The intelligent robot for inspecting fatigue cracks in weld seams of large-span steel bridge decks according to claim 1, characterized in that, The sensor array probe consists of nine TMR sensors, used to detect the horizontal component of the leakage magnetic field in the region above the crack, and convert the horizontal component signal into an electrical signal and output it to the data processing module.
5. The intelligent robot for inspecting fatigue cracks in weld seams of large-span steel bridge decks according to claim 1, characterized in that, It also includes a buzzer electrically connected to the data processing module; The buzzer is used to receive the alarm trigger signal output by the data processing module and perform an audible and visual alarm when the data processing module identifies the abnormal magnetic leakage signal caused by fatigue cracks in the weld area. When the data processing module determines that there is fatigue crack damage in the weld based on the abnormal leakage magnetic field signal, it simultaneously sends a pause command to the motion control module to control the traveling trolley to stop moving.
6. The intelligent robot for inspecting fatigue cracks in weld seams of large-span steel bridge decks according to claim 1, characterized in that, It also includes a storage module electrically connected to the data processing module; The storage module is used to record in real time the location, size, and corresponding detection timestamp information of weld fatigue cracks output by the data processing module.
7. The intelligent robot for inspecting fatigue cracks in weld seams of large-span steel bridge decks according to claim 1, characterized in that, The pulse excitation signal applied to the excitation coil in the TMR phased array detection module has an excitation frequency set to 50Hz and a signal duty cycle set to 50%.
8. The intelligent robot for inspecting fatigue cracks in weld seams of large-span steel bridge decks according to claim 1, characterized in that, The data processing module integrates an AD converter, a preamplifier, and a bandpass filter circuit that are connected in sequence.
9. The intelligent robot for inspecting fatigue cracks in weld seams of large-span steel bridge decks according to claim 1, characterized in that, The motion control module includes a control circuit, a drive motor, a Bluetooth communication unit, and a handheld remote control device; The drive motor is connected to the wheel axle of the walking trolley to provide power; The control circuit and the data processing module achieve real-time data interaction through a bus. The Bluetooth communication unit establishes a wireless communication link between the control circuit and the handheld remote control device. The handheld remote control device sends control commands to the walking vehicle through the control circuit.
10. The intelligent robot for inspecting fatigue cracks in weld seams of large-span steel bridge decks according to claim 1, characterized in that, The motion control module integrates path memory and automatic reset functions. The path memory function is used to dynamically record the complete detection travel path of the traveling trolley along the longitudinal rib weld. The automatic reset function is used to control the traveling trolley to return to the starting position along the detected travel path at a return speed higher than the detection speed.