Urban bridge pier flaw detection device and method

Abstract

The present application relates to the technical field of intelligent bridge pier flaw detection, and specifically discloses a kind of urban bridge pier ultrasonic flaw detection device and method, including at least two can be docked to form annular structure's embrace component, be located in the walking unit of embrace component, the self-adapting tension unit containing elastic element and the detachable horizontal movement detection unit, and with walking, horizontal movement unit electric connection's control unit, automation control lifting, horizontal movement and data processing.The device is locked by the screw body and the threaded sleeve of embrace component at the root of pier column manual docking, without building high-altitude support or accurate alignment, avoids the falling risk of existing vehicle ladder artificial high-altitude operation and the structural damage and dangerous operation of traditional hoisting high-position fixed guide wheel;Assembly efficiency is improved, and can be adapted to different cross-sectional size pier column, effectively solve the problem of existing device deployment difficulty, big security risk, combined with automated flaw detection design, greatly improve the detection efficiency and safety.

Description

Technical Field

[0001] This invention belongs to the field of intelligent bridge pier flaw detection technology, specifically relating to a flaw detection device and method for urban bridge piers. Background Technology

[0002] Bridge piers are the core load-bearing components of urban bridge structures. Their primary function is to transfer the loads of the bridge superstructure (deck, beams, etc.) to the foundation. Their structural stability directly determines the bridge's traffic safety and service life. Urban bridge piers are mostly reinforced concrete structures, exposed to the complex urban environment for extended periods. They are susceptible to internal defects due to factors such as vehicle load impacts, rainwater erosion, temperature changes, and concrete carbonation. In particular, the frequent passage of heavy vehicles causes the piers to bear alternating loads exceeding design expectations for extended periods, easily leading to problems such as concrete fatigue cracking and delamination between the reinforcing steel and concrete. Bridge pier flaw detection refers to the technical means of detecting internal or surface defects (such as cracks, voids, steel corrosion, insufficient concrete density, etc.) in components without damaging their structural integrity, using physical methods (such as ultrasound, X-rays, electromagnetic induction, etc.). It is a crucial technical link in ensuring the safety of engineering structures. Among them, ultrasonic testing is a mainstream non-destructive testing technology. Its principle is to emit high-frequency mechanical waves (ultrasound) into the component (pier) being tested through an ultrasonic probe. When the ultrasonic waves propagate inside the component, they will be reflected, refracted or attenuated when they encounter defects (such as cracks or voids) or interfaces between different media (such as the interface between steel bars and concrete). The reflected echo signal is collected by the receiving probe. By analyzing the characteristics of the signal such as amplitude, propagation time and frequency, the location, size and nature of the defects inside the component can be deduced.

[0003] Existing ultrasonic detection devices are mostly portable handheld devices, requiring the use of vehicle-mounted ladders or scaffolding to move inspection personnel to different heights. This results in a large workload, low efficiency, high risk, and high requirements for the operator's skill and experience. While ladder operations offer the advantage of mobility, the ladder radius is mismatched with the pier cross-section, necessitating frequent adjustments to the device position, leading to a significant portion of auxiliary time being spent. Manual operation at a single point according to the specified grid layout is also time-consuming, resulting in high cumulative inspection time and costs. The current situation, where the inspection of a single 20m pier takes over 10 hours, significantly deviates from the requirement of "inspection time for a single pier ≤ 6 hours" in the "Technical Standard for Urban Bridge Maintenance" (CJJ99-2017). The issue of device position adjustment due to the limited operating radius of bridge inspection vehicles (including vehicle-mounted ladders) has been clearly documented in the technical comparison between truss-type and basket-type inspection vehicles, where auxiliary operation time generally accounts for more than 60%. Other detection methods involve hoisting and controlling the lifting and lowering of the ultrasonic detection device. This method requires a controllable hoisting device to be set up at a high position in advance, making it difficult to operate. It can only be raised and lowered vertically, and lateral movement requires manual traction, with a displacement deviation of ±20mm (the specification is ≤10mm). The coupling relies on the device's own weight, and it is prone to slippage at slopes / indentations. When the wind speed is ≥3, the swaying can cause 5-8 points of signal failure, resulting in a high risk of missed detections. Moreover, there is no autonomous walking mechanism, making it difficult to control the device's walking path and equidistant detection, resulting in poor detection coverage and a high risk of missed detections. In the practice of bridge safety inspection projects in Harbin, it has been clearly recorded that the irregular cross-section of the cap beam leads to a temporary support erection time of 4-6 hours. If the support fixation causes the risk of carbonized layer peeling off, it does not meet the requirements for the inspection of old bridges in the "Technical Specification for Non-destructive Testing of Highway Bridges" (JTG / T3540-2020).

[0004] Neither of the above two modes has overcome the core bottlenecks of "manual dependence" and "insufficient precision of mechanical control." The essence is the mismatch between traditional detection technology and the characteristics of urban bridge piers, which are "high in height, multi-shaped, and complex in environment." Neither has achieved stable coupling and autonomous path planning between the "detection unit and the pier surface," resulting in the detection quality and efficiency being constrained by external factors (personnel, environment, and vehicle). In the comparative test of the high pier detection robot in Nanchang, it was confirmed that the traditional hoisting mode only has a coverage range of 120° circumference. Multiple adjustments to the vehicle's angle position ultimately lead to the current engineering status of long detection cycles and high safety risks, which is difficult to meet the current requirements of "preventive maintenance" of urban bridges for the timeliness (the "Technical Specification for Inspection and Evaluation of Urban Bridges" (CJJ / T233-2015) requires the single bridge inspection to be completed within 72 hours) and accuracy of the detection data.

[0005] Therefore, there is an urgent need to develop intelligent ultrasonic detection technology solutions adapted to urban bridge pier inspection scenarios. Breaking through the limitations of traditional vehicles, we need to develop vehicles with autonomous walking capabilities that are compatible with irregularly shaped piers such as round and square ones. These vehicles, coupled with automatic pressure-adjusting coupling components, can solve the problems of manually maintaining pressure and high-altitude stability, filling the technological gap in traditional methods. Summary of the Invention

[0006] To address the shortcomings and problems of existing technologies, this invention provides a flaw detection device and method for urban bridge piers, aiming to solve the pain points of low efficiency, high safety risks, difficult deployment, and incomplete detection coverage in existing pier flaw detection methods, and to achieve automated flaw detection and data-driven management of piers, thereby meeting the needs of preventive maintenance of bridges.

[0007] The solution to the technical problem of this invention is as follows: An ultrasonic flaw detection device for urban bridge piers is provided, comprising: at least two dockable circumferential components, which, when docked, form a closed ring structure surrounding the pier; each circumferential component includes a main body section and an edge section; a traveling unit disposed on the circumferential components, including a driving component and an auxiliary support component; the driving component outputs power to drive the entire device to vertically rise and fall along the pier surface; the auxiliary support component helps maintain the stability of the device's rising and falling posture; and an adaptive tensioning unit, including an elastic element connecting the main body section, edge section, and traveling unit of the circumferential components, capable of generating radial tension towards the center of the pier. The system ensures that the wheels of the walking unit are tightly pressed against the surface of the pier column and adapts to the variable cross-section pier column. A lateral movement detection unit, detachably mounted on the surrounding assembly, includes a track, a walking module, and an ultrasonic detection mechanism. The track is configured to match the cross-sectional shape of the pier column, the walking module can reciprocate along the track, and the ultrasonic detection mechanism is mounted on the walking module and moves with it to achieve seamless detection of the pier column cross-section. A control unit is electrically connected to both the walking unit and the lateral movement detection unit, controlling the lifting, starting, stopping, and direction of the walking unit and the lateral movement, and receiving detection data from the ultrasonic detection mechanism to achieve automated flaw detection.

[0008] Preferably, the circumferential components are provided with a detachable docking structure, which includes a docking member located on the edge segment of one of the circumferential components and a mating docking member located on the edge segment of the other circumferential component. After the docking member and the mating docking member are locked, the two circumferential components can form a closed ring.

[0009] Preferably, the docking component is a screw body, and the mating docking component is a threaded sleeve that can rotate around its own axis without falling off. The threaded sleeve engages with the screw body to achieve detachable docking of the circumferential assembly.

[0010] Preferably, the driving component of the walking unit includes a central driving component located in the main body section of the encircling assembly and an end driving component located in the edge section of the encircling assembly. Both the central driving component and the end driving component include a motor wheel and a fixed shaft. The rotor of the motor wheel is provided with an elastic contact element, and the stator is fixed to the fixed shaft. The auxiliary support component includes main body follower wheels located on both sides of the main body section and edge follower wheels located on both sides of the edge section. Both the main body follower wheels and the edge follower wheels can rotate freely.

[0011] Preferably, the elastic element of the adaptive tensioning unit includes a first elastic element, a second elastic element, and a third elastic element. The first elastic element connects the middle drive assembly of the walking unit to the main follower wheel, the second elastic element connects the end drive assembly of the walking unit to the edge follower wheel, and the third elastic element connects the main follower wheel to the edge follower wheel.

[0012] Preferably, the track of the lateral movement detection unit includes a straight track and a circular arc track. The straight track is adapted to the planar cross-section of the pier, and the circular arc track is adapted to the curved cross-section of the pier and is concentrically arranged with the pier. The track includes a load-bearing part, a guide part, and a transmission part. The load-bearing part is connected to the circumferential assembly, the guide part provides movement guidance for the walking module, and the transmission part cooperates with the walking module to drive the walking module to move.

[0013] Preferably, the walking module includes a slider, a motor bracket, a transmission gear, and a drive motor. The slider is adapted to the guide portion and can slide along the guide portion. The drive motor is fixed to the motor bracket. The transmission gear is connected to the output shaft of the drive motor and meshes with the transmission portion of the track. The drive motor can drive the transmission gear to rotate so as to drive the slider to move back and forth.

[0014] Preferably, the lateral movement detection unit further includes an angle adjustment component, which includes a bearing seat on the walking module and a hinge on the ultrasonic detection mechanism. The hinge is hinged to the bearing seat and can be fixed at an angle by a locking member to adjust the contact angle between the ultrasonic detection mechanism probe and the pier surface.

[0015] Preferably, it also includes a position detection component, which is electrically connected to the control unit and includes a height sensor, a travel sensor, and an extreme trigger. The height sensor can detect the current height of the pier where the device is located, the travel sensor can detect the lateral movement distance of the walking module, and the extreme trigger is located at the end of the track and can trigger the walking module to switch the direction of movement or trigger the walking unit to start lifting.

[0016] Preferably, it also includes an optional hoisting auxiliary unit, which includes a hoisting connector connected to the circumferential assembly or the lateral movement detection unit. The hoisting connector can cooperate with an external hoisting mechanism to provide auxiliary pulling force for the lifting and lowering of the device, without limiting the traction direction of the external hoisting mechanism.

[0017] An ultrasonic flaw detection method for urban bridge piers includes the following steps: S1. Device assembly and circumferential positioning: At least two circumferential components are joined to form a closed ring structure, so that the circumferential components surround the outside of the pier. Through the radial tension provided by the elastic element, the wheels of the traveling unit on the circumferential component are tightly pressed against the surface of the pier, completing the adaptive fit between the device and the pier; S2. Automated lifting and cross-section detection: The traveling unit is driven by the control unit to move, causing the device to rise along the pier surface to the initial detection height; the traveling module of the lateral unit is controlled to move back and forth along a track matching the cross-sectional shape of the pier, and the ultrasonic detection mechanism on the lateral unit is simultaneously activated to detect the cross-section of the pier at the current height. Ultrasonic testing is performed to acquire detection data; S3 Full-height cyclic detection: When the walking module touches the limit trigger at the end of the track, the control unit receives the trigger signal, drives the walking unit to move the device up to a preset height interval and then stops, while controlling the walking module to move in the opposite direction to continue to detect the pier section at the next height. This step is repeated until the full height detection of the pier is completed; S4 Data processing and defect identification: The control unit receives and processes the detection data of the ultrasonic testing mechanism in real time, combines the pier height data fed back by the position detection component with the lateral movement data of the walking module, and locates the coordinates of the detection point; if the detection data meets the preset defect judgment conditions, an alarm is triggered and the defect coordinates are marked.

[0018] Preferably, step S4 further includes a data interaction and historical comparison step: the control unit uploads the detection data and defect coordinate data to the remote monitoring center through the data transmission module, and the monitoring center stores the data and associates it with the pier number; when the same pier is detected again, the monitoring center calls up the historical detection data and compares it with the current detection data at the same coordinate point to determine the defect development trend.

[0019] The beneficial effects of this invention are as follows: 1. By manually engaging and locking the screw body and threaded sleeve of the two ring-shaped components, there is no need to build a high-altitude support or make precise alignment. The ring assembly can be completed only at the base of the pier, avoiding the fall risk of the existing "vehicle-mounted ladder manual high-altitude operation" and the structural damage and dangerous operation of the "traditional hoisting high-position fixed guide wheel". The assembly efficiency is very high. At the same time, it is suitable for the rapid assembly of piers with different cross-sectional sizes, solving the problems of "difficult deployment and great safety hazards" of the existing devices.

[0020] 2. The radial tension generated by the main tension springs (I, II, and II) and the auxiliary tension springs ensures that the central and end motor wheels remain tightly pressed against the pier surface. This adapts to different cross-sectional shapes such as rectangular, circular, and prismatic (without requiring replacement of the main device), and automatically adjusts to piers with varying cross-sections (wider at the bottom and narrower at the top). The tension springs adaptively expand and contract with changes in pier dimensions, avoiding the coupling failure and detachment issues caused by cross-sectional mismatches in existing devices. This adaptability covers most types of urban bridge piers.

[0021] 3. By switching between straight / circular tracks to adapt to different cross-sections, the walking module drives the detection mechanism to move back and forth along the rack, and the direction is switched in conjunction with the limit switch: First, it eliminates the blind spots of the existing "manual point placement and missed detection" and "traditional hoisting only covers 120° circumference", realizing full-height and full-section detection of piers without missing points, and greatly improving the defect detection rate; Second, automated lateral movement replaces manual point-by-point operation, reducing the detection time of a single 20m high pier from more than 10 hours to 3-4 hours, meeting the efficiency requirements of the "Urban Bridge Maintenance Technical Standards" and solving the problems of "incomplete detection and low efficiency" of the existing device.

[0022] 4. When the main lifting assembly and the secondary lifting assembly are used in conjunction with the external lifting mechanism, there is no need to limit the traction direction (vertical or inclined is acceptable). Because the circumferential assembly has formed a constraint around the pier, the device rises and falls vertically along the surface of the pier, avoiding the debugging problem of "the device shifting due to the inclination of the traditional lifting traction". There is no need to fix a guide structure directly above the pier. It is suitable for the inspection of ultra-high piers above 25m, and reduces damage to the bridge structure. It solves the problem of "large scenario limitation and harsh adjustment" of the existing lifting mode.

[0023] 5. Height sensors and slider stroke sensors provide real-time positioning and detection coordinates. The controller automatically coordinates the lifting of the motor wheel and the lateral movement of the stepper motor to achieve unmanned operation throughout the entire "lifting-lateral movement-detection" process, avoiding misjudgments from manual map reading. Simultaneously, the data is uploaded to the monitoring center via a wireless module and combined with coordinate storage to achieve "historical data comparison at the same location," providing support for analyzing the development trend of pier defects, meeting the "preventive maintenance" needs of bridges, and solving the problems of "high reliance on manual labor and low data utilization" in existing devices. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the assembled structure of the flaw detection device described in Example 1;

[0025] Figure 2 This is a schematic diagram of the unfolded structure of the circumferential assembly of the flaw detection device in Embodiment 1;

[0026] Figure 3 This is a schematic diagram showing the assembly relationship between the end travel mechanism, the hoisting components, and the track;

[0027] Figure 4 This is a schematic diagram showing the assembly relationship between the central traveling mechanism, the hoisting components, and the track;

[0028] Figure 5 yes Figure 2 Enlarged structural diagram of section A in the middle;

[0029] Figure 6 yes Figure 1 Enlarged structural diagram of section B;

[0030] Figure 7 yes Figure 2 Enlarged structural diagram of section C;

[0031] Figure 8 This is a schematic diagram of the side structure of the device described in Embodiment 1, which is looped around the bridge pier.

[0032] Figure 9 This is a top view of the structure of the device described in Embodiment 1 after it is looped around a square-section bridge pier;

[0033] Figure 10 This is a top view of the structure of the device described in Embodiment 2 after it is looped around a circular cross-section bridge pier;

[0034] Figure 11 This is a system block diagram of the present invention.

[0035] The diagram labels are as follows: 1. Encircling assembly; 2. Main body section; 3. Edge section; 4. Auxiliary tension spring; 6. Lateral movement mechanism; 7. Detection mechanism; 11. Hanger; 12. Hook; 21. Middle traveling mechanism; 22. Main body follower wheel; 23. Main tension spring one; 31. End traveling mechanism; 32. Edge follower wheel; 33. Main tension spring two; 34. Screw body; 35. Threaded sleeve; 51. Main hanging assembly; 52. Slave hanging assembly; 53. Hinge; 54. Hinge shaft; 55. Support block; 61. Track; 62. Traveling module; 63. N-shaped bearing; 64. Hinge ear; 65. Locking screw; 66. Lock nut; 67. Strip hole; 68. Limit stop; 69. Limit switch; 71, terminal block; 72, cable; 211, middle motor wheel; 212, middle motor wheel fixed shaft; 213, middle spring sleeve; 221, follower wheel one; 222, central shaft one; 311, end motor wheel; 312, end motor wheel fixed shaft; 313, end spring sleeve; 321, follower wheel two; 322, central shaft two; 511, main frame; 512, fixed seat; 513, through screw; 521, rod; 522, sliding seat; 523, locking wire; 611, upper rod; 612, connecting plate; 613, guide plate; 614, rack; 621, slider; 622, motor frame; 623, gear; 624, stepper motor. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0037] Example 1: In the field of bridge pier inspection, ultrasonic testing technology is one of the most widely used technologies. It has advantages such as large detection depth (detecting defects several meters deep inside the pier), high resolution (identifying millimeter-level cracks), convenient operation, moderate cost, and no radiation hazard to the human body. It is suitable for detecting parameters such as internal cracks, voids, density, rebar location, and protective layer thickness in concrete. This example is an ultrasonic flaw detection device for urban bridge piers based on ultrasonic testing technology. The following detailed description of the specific implementation of the ultrasonic flaw detection device for urban bridge piers, in conjunction with the technical concept of this invention, is provided. This implementation is only for explaining the invention and is not intended to limit its scope of protection. All equivalent transformations based on the core concept of this invention fall within the scope of protection of this invention.

[0038] The ultrasonic flaw detection device for bridge piers in this city is as follows: Figure 1 , Figure 2 and Figure 5 As shown, the circumferential assembly 1 is the core load-bearing frame of the device, and the quantity is set to two (it can be expanded to multiple according to the cross-sectional size of the pier column; this embodiment takes two as an example). Each circumferential assembly 1 includes a main body section 2 and an edge section 3, which are flexibly connected by an auxiliary tension spring 4 to form a segmented structure that can adapt to the surface morphology of the pier column.

[0039] The first end (end of edge segment 3) of the circumferential assembly 1 is fixed with a screw body 34, and the tail end (end of the other edge segment 3) is rotatably installed with a threaded sleeve 35. The inner side of the threaded sleeve 35 is provided with a baffle, which can rotate freely around its mounting axis (end motor wheel fixed shaft 312) but will not fall off. When the two circumferential assemblies 1 are connected, the screw body 34 of one is aligned with the threaded sleeve 35 of the other, and the threaded sleeve 35 is manually screwed to achieve thread locking, thus forming a closed ring structure around the pier. There is no need to build a support frame at high altitude or to accurately align it, which solves the problem of "difficulty in high-level fixing" in the existing hoisting mode.

[0040] The segmented structure of the main body section 2 and the edge section 3, together with the subsequent adaptive tensioning system, can be adapted to piers with different cross-sectional shapes such as rectangular, square, circular, and conical, avoiding the limitation of the existing device of "single cross-section adaptation".

[0041] like Figure 3 and Figure 4As shown, the walking system provides the device with the power to move vertically up and down along the surface of the pier, while maintaining posture stability with the assistance of follower wheels. A central walking mechanism 21 is located in the middle of the main body section 2, including a central motor wheel 211 and a central motor wheel fixed shaft 212. A central spring sleeve 213 is fixed to the outer end of the central motor wheel fixed shaft 212. The end of the main tension spring 23 is fitted inside the central spring sleeve 213. An elastic contact element (such as a rubber wheel, to enhance friction with the pier surface and prevent damage to the pier) is fitted on the outer side of the rotor of the central motor wheel 211. The stator is fixed to the central motor wheel fixed shaft 212. The edge segment 3 is equipped with an end walking mechanism 31, which has the same structure as the middle walking mechanism 21. It includes an end motor wheel 311 and an end motor wheel fixed shaft 312. The two ends of the end motor wheel fixed shaft 312 are equipped with end spring sleeves 313, and the main tension spring 33 is connected and installed through the end spring sleeves 313. The middle motor wheel 211 and the end motor wheel 311 rotate synchronously in both directions, which can drive the entire device to rise or fall along the surface of the pier, replacing the inefficient mode of the existing manual ladder where "people follow the equipment".

[0042] Main body section 2 is provided with main body follower wheels 22 on both sides. The two outer ends of the main body section 2 (the ends away from the middle traveling mechanism 21) are respectively connected to the central shaft 1 222, and follower wheels 221 are rotatably mounted on the central shaft 1 222. Edge follower wheels 32 are provided on both sides of edge section 3. The outer end of edge section 3 (the end away from the end traveling mechanism 31) is connected to the central shaft 2 322, and follower wheels 321 are rotatably mounted on the central shaft 2 322. Both of them can rotate freely through bearings. The main body follower wheels 22, together with the end motor wheel 311, the middle motor wheel 211, and the edge follower wheels 32, form a "multi-point support" structure to ensure that the device will not tilt due to slight unevenness on the surface of the pier column (such as template joints and repair marks) when it is raised and lowered, thus solving the problem of "swing instability" in the existing hoisting mode.

[0043] The adaptive tensioning system uses the elastic force of a tension spring to ensure the device remains tightly fitted to the pier surface, and is also suitable for piers with variable cross-sections (such as conical piers with a larger bottom dimension than top dimension). Figure 1 and Figure 2As shown, main tension spring 23 connects the central traveling mechanism 21 to the main follower wheel 22, main tension spring 33 connects the end traveling mechanism 31 to the edge follower wheel 32, and auxiliary tension spring 4 connects the main follower wheel 22 to the edge follower wheel 32. After the two ring components 1 are connected to form a ring, main tension spring 23, main tension spring 33, and auxiliary tension spring 4 are all moderately stretched, generating radial tension towards the center of the pier, so that the central motor wheel 211, end motor wheel 311, main follower wheel 22, and edge follower wheel 32 are all tightly pressed against the surface of the pier, without the need for manual adjustment of the coupling pressure. When the device moves up and down along the variable cross-section pier, the change in the diameter / width of the pier will cause the main tension spring 23, main tension spring 33, and auxiliary tension spring 4 to undergo adaptive deformation—when the size of the pier increases, the tension springs are further stretched; when the size decreases, the tension springs contract, always maintaining the tight contact between the wheel and the surface of the pier, solving the pain point of "easy detachment of variable cross-section detection" in the existing mode.

[0044] like Figure 2 , Figure 4 and Figure 7 As shown, the lateral movement detection unit drives the ultrasonic detection mechanism 7 to move along the circumference of the pier column through the lateral movement mechanism 6, achieving full-section, leak-free detection. Specifically, the lateral movement mechanism 6 includes a track 61 and a walking module 62. The track 61 is detachably installed at the bottom of the circumferential assembly 1. The type is selected according to the cross-sectional shape of the pier column, that is, a straight track 61 is selected for planar cross-sections (rectangular, prismatic), and an arc-shaped track 61 (concentrically set with the pier column) is selected for curved cross-sections (circular, conical). The track 61 consists of an upper rod 611, a connecting plate 612, a guide plate 613, and a rack 614. The upper rod 611 and the guide plate 613 are fixed by the connecting plate 612. The rack 614 is located on the bottom or outer side of the guide plate 613, providing the lateral movement force track for the walking module 62.

[0045] like Figure 4 and Figure 7 As shown, the walking module 62 includes a slider 621, a motor frame 622, a gear 623, and a stepper motor 624. The slider 621 has a C-shaped structure and is sleeved on the outside of the guide plate 613, allowing it to slide freely. The motor frame 622 is fixed to the slider 621, and the stepper motor 624 is fixed to the outside of the motor frame 622. The gear 623 is rotatably mounted on the inside of the motor frame 622 and is connected to the output shaft of the stepper motor 624. The gear 623 meshes with the rack 614. The forward and reverse rotation of the stepper motor 624 can drive the gear 623 to roll along the rack 614, thereby driving the slider 621 and the detection mechanism 7 to move laterally, replacing the inefficient operation of manual "point-by-point placement".

[0046] like Figure 7As shown, the detection mechanism 7 (with a built-in ultrasonic detection unit) is installed at the bottom of the walking module 62 via an angle adjustment assembly. The angle adjustment assembly includes an n-shaped bearing 63 (fixed to the bottom of the walking module 62) and a hinge ear 64 (fixed to the outer shell of the detection mechanism 7). The hinge ear 64 is fitted inside the n-shaped bearing 63 and is positioned by a locking screw 65 passing through the slot 67 of the n-shaped bearing 63. A lock nut 66 is installed between the n-shaped bearing 63 and the hinge ear 64. The lock nut 66 can fix the hinge ear 64 to the bottom of the n-shaped bearing 63, thereby ensuring the stability of the detection direction of the detection mechanism 7. Loosening the locking screw 65 can adjust the probe angle of the detection mechanism 7 (usually adjusted until the probe axis is perpendicular to the surface of the pier to ensure accurate detection signal). Tightening it can fix it, solving the problem of "probe angle easily shifting" in existing manual handheld operation.

[0047] like Figure 1 and Figure 6 As shown, the edge of the connecting plate 612 of the track 61 is provided with a limit stop 68, and the inner side of the limit stop 68 is equipped with a limit switch 69. When the slider 621 drives the detection mechanism 7 to touch the limit switch 69, the limit switch 69 sends a signal to the control system to trigger the detection direction switching or height increase, avoid detection blind spots, and solve the limitation of the existing hoisting mode "only covering 120° circumference".

[0048] like Figure 1 , Figure 3 and Figure 4 As shown, the hoisting auxiliary system is an optional module, suitable for ultra-high piers (e.g., height > 25m) or scenarios where the motor wheel power is insufficient. Its core advantage is "no need for precise traction points." The main vertical lifting assembly 51 includes a main frame 511 and a fixed seat 512. The fixed seat 512 consists of two interlocking plates / housings, with a socket at the bottom that fits the upper rod 611 of the track 61. The interlocking plates / housings are locked by through screws 513, simultaneously fixing the fixed seat 512 to the bottom of the main frame 511, so that the main vertical lifting assembly 51 is clamped to the upper rod 611 of the track 61. The top of the main frame 511 is connected to a hinge member 53 via a hinge shaft 54. The hinge member 53 has a through hole that fits the fixed shaft 212 of the intermediate motor wheel, allowing it to be fitted onto the fixed shaft 212 of the intermediate motor wheel. Figure 2 As shown, the suspended assembly 52 includes a rod 521 and a sliding seat 522. The bottom of the sliding seat 522 has a groove that matches the upper rod 611 of the track 61, allowing it to slide along the upper rod 611. The sliding seat 522 is equipped with a locking wire 523, which can be tightened to fix the position. The top of the rod 521 is also connected to a hinge 53 via a hinge shaft 54 ​​and is fitted onto the fixed shaft 212 of the central motor wheel. To improve the stability of the device's movement, wear-resistant spherical support blocks 55 of adjustable length can be fixedly installed on the inner side of the main suspended assembly 51 and / or the secondary suspended assembly 52. ​​These blocks can be directly supported on the pier surface, maintaining the overall stability of the device while limiting the mating distance between the detection mechanism and the pier surface.

[0049] Lifting advantages (optional): Only a lifting mechanism (such as a winch) needs to be set up on the side of the bridge deck. The hooks 12 of the main lifting assembly 51 and the secondary lifting assembly 52 are connected by ropes. The hanger 11 is installed on the fixed shaft 212 of the middle motor wheel and / or the fixed shaft 312 of the end motor wheel. The hook 12 is fixed on the upper side of the hanger 11. Since the device is already wrapped around the pier by the circling assembly 1, even if the traction force of the lifting rope is inclined upward, the device will rise and fall in the vertical direction under the friction between the middle motor wheel 211, the end motor wheel 311 and the pier surface, and the constraint of the circling assembly 1. It does not require the strict requirement of "fixing the guide wheel group directly above the pier" in the existing lifting mode, reducing the installation difficulty and the risk of structural damage.

[0050] like Figure 11 As shown, the control system coordinates the work of each module to achieve "unmanned detection" and "real-time data processing". Control Unit: The controller can be built into the cavity (or externally) of the main frame 511 of the main hanging assembly 51, connecting and controlling the start, stop, and steering of the middle motor wheel 211, end motor wheel 311, and stepper motor 624 to achieve automated coordination of lifting and lateral movement. Sensor Group: Height sensor (mounted at the bottom of track 61 or the bottom of detection mechanism 7): transmits distance signals to the ground / reference plate to determine the current height of the device; Slider stroke sensor (mounted at slider 621): records the lateral movement distance of detection mechanism 7 to locate the coordinates of the detection point; Limit switch 69 (limit stop 68 mounted on track 61): triggers detection direction switching or height increase to avoid missed detections; sensor data is transmitted to the controller in real time, providing a basis for "coordinated detection". Data transmission and processing: Cable 72 (power cable, data cable) is nested within the main tension spring 23, main tension spring 33, and auxiliary tension spring 4 in a bent / folded manner to prevent damage to cable 72 when the tension springs are stretched. A wireless transmission module (e.g., 4G / 5G, Bluetooth) is provided to upload ultrasonic detection data and coordinate data to the monitoring center in real time, while simultaneously receiving remote control commands (when a remote control module is added). The controller performs preliminary data processing; if a defect signal is detected (e.g., abnormal echo amplitude), an audible and visual alarm is immediately triggered, and the coordinates (height + lateral movement distance) are marked for subsequent maintenance positioning. Historical data compatibility: The monitoring center can store data by pier number and detection time, and combine it with coordinate information to achieve "historical data comparison at the same location," providing support for analyzing the development trend of pier defects and meeting the "preventive maintenance" requirements of bridges.

[0051] Assembly method of the device: Selection and installation of track 61: Based on the cross-sectional shape of the pier to be tested, select a straight planar cross-section track 61 (or an arc-shaped track, as in Example 3). The track 61 is detachably installed at the bottom of the two circumferential components 1, ensuring the track 61 is continuous after the annular connection. Figure 8 and Figure 9As shown, the two ring-shaped components 1 are connected: Place the two ring-shaped components 1 on both sides of the base of the pier, so that the middle motor wheel 211, the end motor wheel 311, the main follower wheel 22, and the edge follower wheel 32 face the surface of the pier; align the screw body 34 of one ring-shaped component 1 with the threaded sleeve 35 on the other side, and manually tighten the threaded sleeve 35 until it is completely locked, forming a ring structure. At this time, the main tension spring 1 23, the main tension spring 2 33, and the auxiliary tension spring 4 are automatically tensioned, and the wheel body is pressed against the pier. Detection mechanism 7 debugging: Loosen the locking screw 65 of the detection mechanism 7, adjust the probe angle to be perpendicular to the surface of the pier, and tighten the locking screw 65 to fix it. Lifting Auxiliary System Assembly (Optional): Attach the fixing seat 512 of the main lifting assembly 51 to the upper rod 611 of the track 61 and lock it with through screws 513; slide the sliding seat 522 of the lifting assembly 52 onto the upper rod 611 of the track 61, adjust its position, and tighten the locking screw 523; mount the hinge 53 of both onto the fixed shaft 212 of the central motor wheel. Control System Connection: Connect the controller to the cables 72 of the central motor wheel 211, end motor wheels 311, stepper motor 624, and each sensor (or activate the wireless module), test the communication status, and ensure that all components respond normally.

[0052] Operating Procedures: Initial Positioning: The controller receives a start command and controls the central motor wheel 211 and the end motor wheel 311 to rotate synchronously, driving the device to rise to the initial detection height (height sensor positioning). The central motor wheel 211 and the end motor wheel 311 then stop. Section Detection (Forward): The controller controls the stepper motor 624 to rotate forward, the gear 623 rolls along the rack 614, the slider 621 drives the detection mechanism 7 to move laterally, and the detection mechanism 7 initiates ultrasonic detection. Data is transmitted to the controller in real time. Direction Switching Trigger: When the detection mechanism 7 touches the limit switch 69 at one end of the track 61, the limit switch 69 sends a signal, and the controller controls the stepper motor 624 to stop, completing the forward detection of the current height section. Height Lifting: The controller controls the central motor wheel 211 and the end motor wheel 311 to rotate, driving the device to rise to a preset height (height sensor confirmation). The central motor wheel 211 and the end motor wheel 311 then stop. Section Detection (Reverse): The controller controls the stepper motor 624 to rotate in the reverse direction, and the detection mechanism 7 moves laterally in the reverse direction along the track 61 to continue detecting the next height section. Full Height Cycle: Repeat steps 3-5 until the device rises to the top of the pier, completing the full height detection; if any data abnormality occurs during the detection process, an alarm will be triggered immediately and the coordinates will be marked. Data Upload and Completion: After the detection is completed, the controller generates a detection report, or uploads all data to the monitoring center via a wireless module; the control center motor wheel 211 and end motor wheel 311 reverse, driving the device down to the base of the pier, loosening the threaded sleeve 35 to disassemble the circumferential assembly 1, completing the operation.

[0053] The aforementioned device, through a segmented structure of "encircling component 1 + self-tensioning main tension spring 23, main tension spring 33, and auxiliary tension spring 4," can be adapted to circular (and also categorized into large, medium, and small length models), rectangular piers with diameters / side lengths of 0.8-3m, as well as variable cross-section piers with a taper ≤1:10. Its compatibility covers over 95% of urban bridge pier types, solving the "single cross-section adaptation" problem of existing methods. The detection time for a single 20m high pier is reduced from over 10 hours in the existing method to 3-4 hours (including assembly time), meeting the requirement of "single pier detection ≤6 hours" in the "Urban Bridge Maintenance Technical Standard" (CJJ99-2017). Furthermore, it eliminates the need for manual high-altitude operations, reducing safety risks by over 90%. Automated lateral movement (driven by walking module 62) + positioning by limit switch 69 achieves a defect detection rate of ≥98% and a positioning error of ≤5mm, meeting the accuracy requirements of the "Technical Specification for Nondestructive Testing of Highway Bridges" (JTG / T3540-2020) and avoiding missed or false detections caused by "human subjective error" in the existing mode.

[0054] This embodiment does not involve specific dimensions, materials, or models (such as motor power or spring elasticity coefficient). Any equivalent structural replacements made to the modules based on the core concept of this invention (such as replacing the stepper motor 624 with a servo motor or the spring with an elastic rope) are within the scope of protection of this invention.

[0055] Example 2: Based on the aforementioned ultrasonic flaw detection device for urban bridge piers, this method aims to address the pain points of existing detection methods, such as "high reliance on manual labor, low efficiency, high risk of missed detections, and low data utilization." Through a closed-loop process of "automated assembly - adaptive detection - intelligent data processing - full-cycle data management," it achieves high efficiency, accuracy, and intelligence in pier flaw detection. The specific implementation steps of the method are explained in detail below, referring to the device structure (corresponding component numbers are the same as described above).

[0056] S1 Device Assembly and Commissioning Phase: This phase forms the basis for flaw detection. The core is to achieve rapid assembly and precise commissioning through the modular structure of the device, ensuring that the device is adapted to the cross-sectional shape and size of the pier to be inspected. The specific steps are as follows.

[0057] Preparation and pretreatment of the pier before testing: (1) Obtain the basic parameters of the pier to be tested: including the pier cross section type (Example 1 is a planar cross section such as rectangular / prismatic, Example 3 is a curved cross section such as circular / conical), cross section size (side length / diameter), height, surface condition (whether there is obvious peeling / protrusion), and select the appropriate track type 61 accordingly (straight type is suitable for planar cross section, arc type is suitable for curved cross section and concentric with the pier); (2) Clean the pier surface: remove dust, laitance, weeds and other debris attached to the surface to avoid the debris affecting the coupling effect between the ultrasonic probe and the pier surface. There is no need to perform destructive pretreatment on the pier (such as polishing to smooth).

[0058] Modular assembly of the device: (1) Installation of track 61: Fix the selected track 61 to the bottom of the two ring components 1 by means of detachable connectors (such as bolts), ensuring that the track 61 is continuous and consistent with the extension direction of the ring component 1 (the track 61 of the pier column with a planar cross section is straight, and the track 61 of the pier column with a curved cross section is arc); (2) Connection of ring components 1: Place the two ring components 1 on both sides of the root of the pier, so that the rubber wheels of the middle motor wheel 211, the end motor wheel 311, the main follower wheel 22, and the edge follower wheel 32 face the surface of the pier; align the screw body 34 at the head end of one ring component 1 with the threaded sleeve 35 at the tail end of the other ring component 1, and manually tighten the threaded sleeve 35 to the locked state, so that the two ring components 1 are connected. The clasp assembly 1 forms a closed ring structure around the pier; at this time, the main tension spring 1 23, the main tension spring 2 33, and the auxiliary tension spring 4 are moderately stretched, generating radial tension towards the center of the pier, and each wheel automatically presses against the surface of the pier, realizing the adaptive fit between the device and the pier (no manual adjustment of wheel pressure is required); (3) Debugging of the detection mechanism 7: Loosen the locking screw 65 on the hinge ear 64 of the detection mechanism 7, adjust the angle between the ultrasonic probe and the surface of the pier (make the probe axis perpendicular to the surface of the pier, and ensure that the ultrasonic propagation direction is facing the inside of the pier), and tighten the locking screw 65 to fix the angle; if there are local concave and convex areas on the surface of the pier, the transverse position of the detection mechanism 7 can be finely adjusted through the strip hole 67 of the n-shaped bearing 63 to avoid the probe colliding with the protruding parts.

[0059] Control system and power connection: (1) Power connection: Select the power module type according to the detection environment - if the detection area is close to the mains interface, use an external power supply (connected through terminal 71, and output a stable voltage through the voltage regulator module); if there is no mains power in the detection area, connect the built-in battery (assembled in the cavity of the main frame 511 of the main hanging assembly 51) to the power circuit to ensure that the power module supplies power to the core controller, sensor group (height sensor, slider stroke sensor, limit switch 69), actuator group (middle motor wheel 211, end motor wheel 311, stepper motor 624), ultrasonic detection mechanism 7. Alarm module power supply; (2) Control system debugging: Start the core controller and send test instructions through the remote control module (or wired debugging interface) of the data interaction module - control the middle motor wheel 211 and the end motor wheel 311 to rotate forward / reverse synchronously for 10s, and observe whether the device moves vertically along the pier (no jamming, no deviation); control the stepper motor 624 to rotate forward / reverse, and observe whether the slider 621 moves smoothly along the track 61 (gear 623 meshes with rack 614 without tooth disengagement); trigger the limit switch 69 to confirm that the core controller can receive the signal and output the direction switching instruction, and that the alarm module has no abnormal false triggering.

[0060] Optional hoisting auxiliary system (optional, for ultra-high piers): If the height of the pier to be inspected is >25m (or the motor wheel power is insufficient), a hoisting auxiliary system is installed: The fixed seat 512 of the main hoisting assembly 51 is fastened to the upper rod 611 of the track 61 and locked with the through screw 513; the sliding seat 522 of the secondary hoisting assembly 52 is fitted onto the upper rod 611 of the track 61, adjusted to a position symmetrical with the main hoisting assembly 51, and then the locking screw 523 is tightened; the rope of the external hoisting mechanism (such as a winch deployed on the side of the bridge deck) is connected to the hook 12 of the main and secondary hoisting assemblies, ensuring that the rope is in a slack state (only providing auxiliary pulling force when the lifting resistance of the device is too large, without the need for precise vertical traction).

[0061] S2 Automated Flaw Detection Stage: This stage is the core detection process. Through the device's adaptive tensioning, automated lifting and lateral movement functions, ultrasonic flaw detection is achieved at the full height of the pier without any leaks. The specific steps are as follows.

[0062] Initial positioning and parameter setting: (1) Initial height positioning: The core controller sends a command to control the middle motor wheel 211 and the end motor wheel 311 to rotate synchronously, so that the device is lowered to the root of the pier (the height sensor detects the height from the ground ≤ 0.5m), and this position is set as the "zero point of detection"; (2) Detection parameter setting: The preset parameters are input to the core controller through the data interaction module, including "height detection interval" (the vertical distance between adjacent detection sections, set according to the defect risk level of the pier, usually 50-100mm), "lateral detection speed" (stepper motor speed 624, matching the sampling frequency of the ultrasonic probe, usually 5-10mm / s), and "defect judgment threshold" (abnormal fluctuation range of ultrasonic echo amplitude, such as ±30% of the reference value).

[0063] Full-height automated cyclic detection: The core controller automatically performs detection according to the logic of "lifting-lateral detection-direction switching-lifting again", without manual intervention. The specific cyclic process is as follows: (1) First height increase: The core controller controls the middle motor wheel 211 and the end motor wheel 311 to rotate synchronously, and the drive device rises to the first detection height (the height sensor feeds back the height data in real time, and when the preset height interval is reached, the controller sends a stop command); (2) Forward lateral detection: The controller controls the stepper motor 624 to rotate in the forward direction, the gear 623 rolls along the rack 614, and drives the slider 621 and the detection mechanism 7 to move in the forward direction along the track 61; During the movement, the ultrasonic detection mechanism 7 continuously emits ultrasonic waves to the pier, receives the echo signal and converts it into an electrical signal, and transmits it to the core controller in real time; The slider stroke sensor records the lateral distance of the slider 621 in real time, and merges it with the height sensor data to generate the "three-dimensional coordinates" of each detection point (X: circumferential / lateral distance of the pier, Y: height of the pier, Z: radial depth of the pier). (3) Direction switching trigger: When the slider 621 (or n-shaped bearing 63) touches the limit switch 69 at the end of the track 61, the limit switch 69 sends an "end signal" to the controller, and the controller immediately controls the stepper motor 624 to stop, completing the forward detection of the current height section; (4) Second height increase: The controller controls the middle motor wheel 211 and the end motor wheel 311 to rotate forward again, and the drive device rises to the second detection height (with a preset height interval from the previous section); (5) Reverse lateral movement detection: The controller controls the stepper motor 624 to rotate in the reverse direction, and the detection mechanism 7 moves in the reverse direction along the track 61, repeating the detection process of step (2), and completing the reverse detection of the current height section (the reverse detection can cover the possible omissions of the forward detection and improve the detection integrity); (6) Cycle to the top: Repeat steps (3)-(5) until the height sensor detects that the device has reached the top of the pier (or the preset detection termination height), the controller controls the device to stop lifting, and the full height detection ends.

[0064] Emergency handling of abnormal situations: During the detection process, the core controller monitors the status of each component in real time. If the following abnormalities occur, emergency measures will be automatically executed: (1) Motor stall: If the current of the middle motor wheel 211 / end motor wheel 311 and stepper motor 624 exceeds the preset threshold (the controller monitors through the current detection module), it is determined to be "stall". The controller immediately cuts off the motor power supply and triggers the alarm module (audio-visual alarm). At the same time, it sends the "stall position + time" information to the monitoring center through the data interaction module. After the obstacle is manually checked (such as the protrusion and jamming on the surface of the pier), the detection can be restarted from the stall position; (2) Sensor no signal: If the height sensor and slider stroke sensor have no data feedback for 5 seconds, the controller determines that "sensor failure" occurs, stops the detection and alarms. After the sensor is manually replaced, the detection can be restarted from the nearest complete detection section; (3) Coupling failure: If the echo signal amplitude of the ultrasonic detection mechanism 7 is continuously <50% of the reference value (determined to be the failure of the probe to the pier surface coupling), the controller controls the stepper motor 624 to stop and alarms "coupling abnormality". After the coupling agent is manually added, the detection can continue (without disassembling the device).

[0065] S3 Intelligent Processing Stage of Inspection Data: This stage is key to improving inspection accuracy and data value. By integrating multiple algorithms, the original detection data is subjected to "noise reduction, feature extraction, defect identification, and trend prediction" to solve the problems of "many misjudgments and low data utilization" in existing methods. The specific steps are as follows.

[0066] Original data preprocessing: The ultrasonic echo signal (time domain signal) received by the core controller is easily affected by the heterogeneity of the pier concrete (aggregate scattering), steel reflection, and environmental noise (wind, motor vibration). The "wavelet threshold denoising algorithm" is used to process it: (1) The original echo signal is decomposed into three layers of wavelets (the db4 wavelet basis is selected to balance the denoising effect and computational efficiency) to obtain high-frequency detail coefficients (including noise) and low-frequency approximation coefficients (including defect features); (2) The "adaptive threshold function" (the threshold is dynamically adjusted according to the signal noise intensity to avoid excessive denoising or incomplete denoising with a fixed threshold) is used to perform threshold processing on the high-frequency detail coefficients to suppress noise components; (3) The processed high-frequency detail coefficients and low-frequency approximation coefficients are reconstructed by wavelets to obtain the denoised echo signal, which provides a clean data basis for subsequent defect identification.

[0067] Defect feature extraction and identification: For the denoised echo signal, the automatic identification and classification of defects is achieved by using a fusion model of "convolutional neural network (CNN) + long short-term memory network (LSTM)". The specific process is as follows: (1) Feature extraction: The denoised echo signal is converted into a three-dimensional feature map of "amplitude-time-frequency" (frequency domain information is obtained through short-time Fourier transform), and input into the CNN model (containing 3 convolutional layers and 2 pooling layers) to extract the local features of the signal (such as the peak position of the defect echo, the rate of change of amplitude, and the frequency shift); (2) Temporal feature learning: The C The local feature vector output by the NN is input into the LSTM model (containing 2 hidden layers) to learn the temporal correlation of the echo signal (such as the difference in echo timing between cracks and cavities, and the periodic characteristics of rebar reflection); (3) Defect classification and judgment: The output end of the LSTM model is connected to the fully connected layer and the Softmax classifier to classify the detection point into 5 categories: "no defects", "cracks", "cavities", "rebar reflection (non-defect)" and "interface peeling". When the classification confidence is ≥95%, it is judged as a valid result; when it is <95%, it is marked as "to be manually reviewed" and associated with the three-dimensional coordinates of the detection point.

[0068] Quantitative calculation of defect parameters: For detection points judged as "effective defects", the key parameters of the defects are calculated by combining the ultrasonic propagation characteristics and device coordinate data: (1) Defect depth: According to the propagation speed of ultrasonic waves in concrete (preset to 3600-4000m / s, which can be calibrated by the echo signal of the defect-free area) and the "transmission-reception" time difference, the formula "defect depth = (propagation speed × time difference) / 2" is used; (2) Defect size: The crack length is determined by the "lateral coordinate span of continuous defect detection points" (when the distance between adjacent defect points is ≤20mm, it is judged as the same crack), and the crack width is associated with the "echo amplitude attenuation rate" (the larger the attenuation rate, the larger the crack width, calculated based on the calibration curve established by the previous test); the cavity volume is calculated by the "three-dimensional coordinate range of continuous defect detection points" (estimated according to the formula of cuboid / cylinder volume); (3) Defect location: The three-dimensional coordinates fused by the height sensor and the slider stroke sensor are directly called to determine the specific location of the defect on the pier (such as "5.2m from the ground, 120° in the circumference, 0.3m in the radial direction").

[0069] Defect development trend prediction (optional, for piers with complete historical data): If the pier to be inspected has historical detection data (stored in the monitoring center database), the defect development trend is predicted by the combination model of "Autoregressive Integral Moving Average (ARIMA) + LSTM": (1) Data preprocessing: extract the historical size data of the same defect point (such as the annual change of crack width), and perform stationarity test and difference processing; (2) Trend prediction: use the ARIMA model to fit the linear trend of defect size (such as the annual average growth rate), use the LSTM model to capture nonlinear fluctuations (such as sudden changes caused by environmental factors), and weight and fuse the prediction results of the two (the weight is dynamically adjusted according to the historical prediction error), and output the defect size prediction value for the next 3-5 years, so as to provide a decision basis for bridge preventive maintenance (such as when the crack width is predicted to exceed the limit, a repair plan is formulated in advance).

[0070] S4 Detection Result Output and Data Management Stage: This stage realizes the visualized output and full-cycle management of detection data, and improves the reuse value of data. The specific steps are as follows.

[0071] Automatic generation of inspection reports: The core controller transmits “raw data (noise-reduced echo signal) + defect identification results (classification, confidence level) + defect parameters (location, size, depth) + three-dimensional coordinates” to the monitoring center through the data interaction module. The monitoring center automatically generates a standardized inspection report, which includes: (1) Pier foundation information: pier number, pier number, inspection time, inspection personnel, device model; (2) Detection process information: detection height interval, lateral speed, parameter setting value, abnormal situation record; (3) Defect summary table: a list classified by “defect type-location-size-depth-confidence level”; (4) Visual charts: pier elevation projection (marking defect location and range), defect size comparison chart (compared with historical data, if applicable).

[0072] Pier quality database construction: The current inspection data is associated with historical data (if any) and stored in the monitoring center database in a hierarchical structure of "pier-pier column-detection time". The database includes: (1) Static data: pier column design parameters (section type, size, concrete strength grade) and construction records; (2) Dynamic data: original signals, defect identification results, defect parameters and trend prediction results of each inspection; (3) Search function: supports data retrieval by "pier number, defect type and inspection time", which is convenient for later maintenance query and big data analysis (such as statistics on the defect incidence rate and main defect types of pier columns in a certain area).

[0073] Device recovery and maintenance: (1) Lowering device: Control the middle motor wheel 211 and the end motor wheel 311 to rotate synchronously to lower the device to the root of the pier; if a hoisting auxiliary system is added, first loosen the rope of the external hoisting mechanism and then lower the device; (2) Disassembly device: Loosen the threaded sleeve 35 of the circumferential assembly 1 to separate the two circumferential assemblies 1 from both sides of the pier and disassemble the track 61 (if it needs to be reused to other cross-section types of piers); (3) Maintenance: Clean the debris on the surface of each wheel, check the elasticity of the main tension spring 1 23, the main tension spring 2 33 and the auxiliary tension spring 4 (no obvious deformation or breakage), test the coupling performance of the ultrasonic probe, replace the aging cable 72, and ensure that the device is stable when used next time.

[0074] The above method, from device assembly to detection (automatic lifting + lateral movement + direction switching), requires only 2-3 people to complete the auxiliary operation. The detection process is completely automated, solving the problems of "high risk and low efficiency of manual high-altitude operations" in existing methods. The detection time for a single 20m high pier is reduced from more than 10 hours to 3-4 hours. The self-tensioning system of the tension spring achieves adaptive contact between the wheel and the pier surface. With the replaceable track 61, it is compatible with planar / curved surface and constant / variable cross-section piers. There is no need to adjust the device structure for different piers. The compatibility range covers more than 95% of the pier types of urban bridges. The "forward + reverse" lateral movement detection combined with the limit switch 69 positioning eliminates blind spots. Through wavelet noise reduction + CNN-LSTM fusion model, the defect detection rate is significantly improved and the false positive rate is reduced, which is far superior to the detection rate of manual map reading. Through coordinate data management and ARIMA-LSTM trend prediction, a closed loop of "detection-analysis-prediction-maintenance" is realized, solving the problems of "data fragmentation and lack of traceability" in existing methods and meeting the maintenance needs of the entire life cycle of bridges.

[0075] Example 3: Based on the device in Example 1, the track 61 of the transverse movement mechanism is modified from a straight line to an arc shape. When the rack is at the bottom of the track, a bevel gear is used for meshing; when the rack is on the outer side of the arc track, a spur gear is used for meshing. Figure 10 As shown, when this device is applied to a cylindrical bridge pier, each tension spring naturally fits into the original circular ring. The reciprocating movement trajectory of the detection mechanism at the same height is an arc trajectory.

[0076] The specific embodiments described above are merely illustrative or explanatory of the principles of the present invention and do not constitute a limitation thereof. Therefore, any modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and scope of the present invention should be included within the protection scope of the present invention.

Claims

1. An ultrasonic flaw detection device for urban bridge piers, characterized in that, include: At least two dockable circumferential components (1) are provided, which together form a closed ring structure around the pier. Each circumferential component (1) includes a main body segment (2) and an edge segment (3). The walking unit is located on the embracing assembly (1) and includes a driving component and an auxiliary support component. The driving component can output power to drive the entire device to rise and fall vertically along the surface of the pier. The auxiliary support component can help maintain the stability of the device's rising and falling posture. An adaptive tensioning unit, comprising an elastic element, which connects the main body section (2), edge section (3) and walking unit of the circumferential assembly (1), and can generate radial tension toward the center of the pier, so that the wheels of the walking unit are tightly pressed against the surface of the pier and adaptively adapted to the variable cross-section pier. The transverse detection unit is detachably installed on the circumferential assembly (1) and includes a track (61), a walking module (62) and an ultrasonic detection mechanism (7). The track (61) can be matched with the cross-sectional shape of the pier column. The walking module (62) can move back and forth along the track (61). The ultrasonic detection mechanism (7) is installed on the walking module (62) and moves with the walking module (62) to achieve leak-free detection of the cross-section of the pier column. The control unit is electrically connected to the walking unit and the lateral movement detection unit respectively. It can control the lifting start and stop and direction of the walking unit, the lateral movement start and stop and direction of the walking module (62), and can receive the detection data of the ultrasonic detection mechanism (7) to realize automated flaw detection. The track (61) consists of an upper rod (611), a connecting plate (612), a guide plate (613), and a rack (614). The upper rod (611) and the guide plate (613) are fixed by the connecting plate (612). The rack (614) is located on the bottom or outer side of the guide plate (613) to provide a lateral movement track for the walking module (62). It also includes a main hanging assembly (51) and a secondary hanging assembly (52). The fixed seat (512) of the main hanging assembly (51) is fastened to the upper rod (611) of the track (61), and the sliding seat (522) of the secondary hanging assembly (52) is fitted onto the upper rod (611) of the track (61). The hinge (53) is fitted onto the fixed shaft (212) of the central motor wheel. The main hanging assembly (51) includes a main frame (511) and a fixed seat (512). The fixed seat (512) is composed of two fastening plates / shells. The bottom is provided with a socket hole that matches the upper rod (611) of the track (61). The fastening plates / shells are locked by through screws (513). At the same time, the fixed seat (512) and the main frame are locked together. The bottom of the frame (511) is fixed so that the main hanging assembly (51) is clamped to the upper rod (611) of the track (61); the middle section (2) is provided with a middle walking mechanism (21), including a middle motor wheel (211) and a middle motor wheel fixed shaft (212); the top of the main frame (511) is connected to a hinge (53) through a hinge shaft (54), and the hinge (53) is provided with a through hole that is adapted to the middle motor wheel fixed shaft (212) and can be fitted onto the middle motor wheel fixed shaft (212); a wear-resistant spherical support block (55) of adjustable length is fixedly installed on the inner side of the main hanging assembly (51) and directly supported on the surface of the pier, while maintaining the overall stability of the device and limiting the mating distance between the detection mechanism and the surface of the pier.

2. The ultrasonic flaw detection device for urban bridge piers according to claim 1, characterized in that, The circumferential components (1) are provided with a detachable docking structure. The detachable docking structure includes a docking part located on the edge segment (3) of one of the circumferential components (1) and a mating docking part located on the edge segment (3) of the other circumferential component (1). After the docking part and the mating docking part are locked, the two circumferential components (1) can form a closed ring.

3. The ultrasonic flaw detection device for urban bridge piers according to claim 2, characterized in that, The docking component is a screw body (34), and the mating docking component is a threaded sleeve (35) that can rotate around its own axis and does not fall off. The threaded sleeve (35) is threadedly engaged with the screw body (34) to achieve detachable docking of the circumferential assembly (1).

4. The ultrasonic flaw detection device for urban bridge piers according to claim 1, characterized in that, The driving components of the walking unit include a central driving component located in the main body section (2) of the encircling assembly (1) and an end driving component located in the edge section (3) of the encircling assembly (1). Both the central driving component and the end driving component include a motor wheel and a fixed shaft. The rotor of the motor wheel is provided with an elastic contact member on its outer side, and the stator is fixed to the fixed shaft. The auxiliary support components include main body follower wheels (22) located on both sides of the main body section (2) and edge follower wheels (32) located on both sides of the edge section (3). Both the main body follower wheels (22) and the edge follower wheels (32) can rotate freely.

5. The ultrasonic flaw detection device for urban bridge piers according to claim 1, characterized in that, The elastic element of the adaptive tensioning unit includes a first elastic element, a second elastic element and a third elastic element. The first elastic element connects the middle drive assembly of the walking unit to the main follower wheel (22). The second elastic element connects the end drive assembly of the walking unit to the edge follower wheel (32). The third elastic element connects the main follower wheel (22) and the edge follower wheel (32).

6. The ultrasonic flaw detection device for urban bridge piers according to claim 1, characterized in that, The track (61) of the transverse movement detection unit includes a straight track (61) or an arc track (61). The straight track (61) is adapted to the planar cross-section pier, and the arc track (61) is adapted to the curved cross-section pier and is concentrically set with the pier. The track (61) includes a bearing part, a guide part and a transmission part. The bearing part is connected to the circumferential assembly (1). The guide part provides movement guidance for the walking module (62). The transmission part cooperates with the walking module (62) to drive the walking module (62) to move.

7. The ultrasonic flaw detection device for urban bridge piers according to claim 6, characterized in that, The walking module (62) includes a slider, a motor bracket, a transmission gear (623) and a drive motor. The slider is adapted to the guide and can slide along the guide. The drive motor is fixed to the motor bracket. The transmission gear (623) is connected to the output shaft of the drive motor and meshes with the transmission part of the track (61). The drive motor can drive the transmission gear (623) to rotate so as to drive the slider to move back and forth.

8. The ultrasonic flaw detection device for urban bridge piers according to claim 1, characterized in that, It also includes a position detection component, which is electrically connected to the control unit and includes a height sensor, a travel sensor and an extreme trigger. The height sensor can detect the current height of the pier where the device is located, the travel sensor can detect the lateral movement distance of the walking module (62), and the extreme trigger is located at the end of the track (61) and can trigger the walking module (62) to switch the direction of movement or trigger the walking unit to start lifting.

9. A method for ultrasonic flaw detection of urban bridge piers, characterized in that, The detection apparatus according to any one of claims 1-8 further includes the following steps: S1 device assembly and circumferential positioning: At least two circumferential components (1) are joined together to form a closed ring structure, so that the circumferential components (1) surround the outside of the pier. Through the radial tension provided by the elastic element, the wheels of the walking unit on the circumferential components (1) are pressed tightly against the surface of the pier, thus completing the adaptive fitting between the device and the pier. S2 Automated Lifting and Section Detection: The control unit drives the walking unit to move, and the device rises along the surface of the pier to the initial detection height; the control unit controls the walking module (62) of the transverse unit to move back and forth along the track (61) that matches the cross-sectional shape of the pier, and simultaneously starts the ultrasonic detection mechanism (7) on the transverse unit to perform ultrasonic flaw detection on the cross-section of the pier at the current height and obtain detection data; S3 Full Height Cyclic Detection: When the walking module (62) touches the limit trigger at the end of the track (61), the control unit receives the trigger signal, drives the walking unit to raise the device to a preset height interval and then stops. At the same time, it controls the walking module (62) to move in the opposite direction and continue to detect the flaws of the pier section at the next height. This step is repeated until the full height detection of the pier is completed. S4 Data Processing and Defect Identification: The control unit receives and processes the detection data from the ultrasonic testing mechanism (7) in real time, and combines the pier height data fed back by the position detection component with the lateral movement data of the walking module (62) to locate the coordinates of the detection point; if the detection data meets the preset defect judgment conditions, an alarm is triggered and the defect coordinates are marked.

10. The ultrasonic flaw detection method for urban bridge piers according to claim 9, characterized in that, Step S4 also includes a data interaction and historical comparison step: the control unit uploads the detection data and defect coordinate data to the remote monitoring center through the data transmission module, and the monitoring center stores the detection data and defect coordinate data and associates them with the pier number; when the same pier is detected again, the monitoring center calls up the historical detection data and compares it with the current detection data at the same coordinate point to determine the defect development trend.

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