A concrete bridge bottom surface crack detection device

Abstract

The application belongs to the technical field of sensor detection, and discloses a concrete bridge bottom surface crack detection device, which comprises two symmetrically arranged moving trolleys and a controller for overall machine control, the upper end of the moving trolleys is fixed with a support plate, and further comprises two groups of supporting assemblies, two groups of multi-position connecting assemblies, two groups of sling detection assemblies, a plurality of visual detection assemblies and a group of plug-in locking assemblies. The sling detection assembly is used for identifying and calculating the diameter of the sling, the multi-position connecting assembly is used for avoiding the sling root by root, only a single locking rod is separated in the whole process, the connection strength is reliable, continuous operation can be realized without disassembling the equipment, the visual detection assembly can be adaptively switched between the cushioning and rigid connection modes, the overall rigidity is improved by the plug-in locking assembly, the arm end flutter is inhibited, and finally the effects of continuous detection, stable operation, clear imaging and consistent precision in different diameter sling scenes are realized.

Description

Technical Field

[0001] This invention belongs to the field of sensor detection technology, and in particular relates to a device for detecting cracks on the bottom surface of concrete bridges. Background Technology

[0002] Over 90% of structural damage to concrete bridges is caused by crack propagation, which directly reflects the bridge's bending and shear bearing capacity and long-term durability. Therefore, automated visual sensing detection of cracks at the bottom of beams is a key technological direction for bridge operation and maintenance. Current mainstream automated inspection methods generally employ a bridge deck-walking inspection trolley paired with a telescopic cantilever robotic arm. A visual image sensor is mounted at the end of the cantilever and extends to the bottom of the beam. The inspection trolley moves at a constant speed along the longitudinal direction of the bridge deck, driving the image sensor to complete a full-area image scan of the bridge beam bottom. Image recognition algorithms then analyze the crack location, width, length, and other defect data to achieve automated quantitative detection of cracks at the bottom of the beam.

[0003] However, for cable-stayed concrete bridges (such as tied arch bridges and self-anchored suspension bridges), the longitudinally distributed cables on the bridge deck can block the connection between the trolley and the cantilever arm. Existing testing equipment cannot pass through directly and must be stopped and manually disassembled, repositioned and reassembled before continuing testing. This not only significantly reduces testing efficiency, but also causes the equipment calibration parameters to become invalid due to repeated disassembly and reassembly, resulting in a continuous decline in the accuracy of crack location and size measurement. Summary of the Invention

[0004] The purpose of this invention is to address the problems existing in the prior art by providing a device for detecting cracks on the bottom surface of concrete bridges.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: a concrete bridge bottom surface crack detection device, comprising two symmetrically arranged mobile trolleys and a controller for overall machine control, wherein the upper end of the mobile trolley is fixed with a support plate, and further comprising two sets of support components, two sets of multi-position connection components, two sets of suspension cable detection components and multiple vision detection components. The multi-position connection component is fixedly installed between the support plate and the support component to realize the disengageable connection between the mobile trolley and the support component, and to continuously pass through the bridge sling by unlocking and avoiding at each point. The sling detection component is fixed to the front end of the multi-position connection component in the direction of travel and is used to identify and detect slings; Multiple vision detection components are evenly installed on the upper surface of the support component to acquire images of the bottom surface of the concrete bridge and identify cracks; The two sets of support components are connected by plug-in locking components.

[0006] Preferably, the support assembly includes a vertically arranged fixed plate with a groove at its lower end. A support plate is rotatably connected to the groove via a connecting shaft. The support plate and the connecting shaft are fixedly connected. One end of the connecting shaft is connected to a torque motor, which drives the support plate to switch between a folded storage state and a horizontal working state.

[0007] Preferably, the support plate is composed of multiple connecting plates spliced ​​together, and adjacent connecting plates are detachably fixedly connected by bolts.

[0008] Preferably, the multi-position connection assembly includes a mounting shell fixed to the upper end of the support plate and a mounting base fixed to the upper end of the fixed plate. Multiple electric actuators are fixed at equal intervals along the longitudinal direction on the inner wall of the mounting shell. A push plate is fixed to the moving end of each electric actuator. Two locking rods are symmetrically fixed on the side of the push plate away from the electric actuators. The side wall of the mounting base is provided with locking grooves that are inserted into the locking rods one by one. The front end of the locking rod is provided with a conical structure for automatic guidance and centering during the insertion process. The interval between two adjacent sets of locking rods is greater than the diameter of the sling, ensuring that the sling can pass completely when only one set of locking rods retracts to make way each time.

[0009] Preferably, both the upper and lower ends of the mounting base are fixed with positioning shells. The horizontal part of the positioning shell is equidistantly fitted with multiple electric actuators II in the vertical direction. The moving end of the electric actuator II is fixed with a push plate II. Multiple insertion rods are fixed on the side of the push plate II away from the electric actuator II. The surface of the mounting base is provided with insertion grooves that match and insert with the insertion rods. The rod wall of the locking rod is provided with insertion holes that match and insert with the insertion rods. The insertion rod cooperates with the insertion groove and insertion hole to limit and lock the end of the locking rod.

[0010] Preferably, the sling detection assembly includes two extension plates respectively fixed to the front end of the mounting base and the mounting shell. The front end of the extension plate is provided with a notch. A flip plate is rotatably connected in the notch via a rotating shaft. A torque return spring sleeved on the outside of the rotating shaft is fixed between the flip plate and the extension plate. An angle sensor is installed on the outer wall of the extension plate. The input end of the angle sensor is fixedly connected to one end of the rotating shaft. The angle sensor is used to collect the deflection angle of the flip plate.

[0011] Preferably, the visual inspection component includes a positioning cylinder fixed to the upper end of the support plate, the inner wall of the positioning cylinder is fixed with a mounting column by a shock-absorbing damping rubber sleeve, and a visual image sensor is fixed to the top of the mounting column.

[0012] Preferably, an expanded circular shell is integrally connected to the upper outer side of the positioning cylinder, and multiple electric actuators are uniformly inserted into the side wall of the expanded circular shell along the circumference. An arc-shaped extrusion plate is fixed to the moving end of the electric actuator, and the arc of the arc-shaped extrusion plate matches the arc of the outer wall of the mounting column.

[0013] Preferably, the plug-in locking assembly includes an insert groove opened at the end of one of the connecting plates, a screw drive mechanism is installed on the inner wall of the insert groove, a movable plate is fixed on the nut seat of the screw drive mechanism, a plurality of parallel plug-in rods are fixed on the side wall of the movable plate, and a through hole is opened at the end of the connecting plate for the plug-in rods to pass through. The other connecting plate has a plug groove at one end that matches the plug rod for insertion. The outer port of the plug groove has a tapered expansion groove for guiding the plug rod to automatically align and insert.

[0014] Compared with existing technologies, the present invention has the following advantages: 1. This invention, through the cooperation of multi-position connection components and sling detection components, adopts a multi-position, one-by-one sling crossing method. Throughout the sling crossing process, only one set of locking rods remains in a disengaged state. Under the premise of ensuring connection strength, the sling obstacle can be continuously crossed without the need for overall disassembly and assembly, thus avoiding the time consumption and calibration failure problems caused by repeated disassembly and assembly.

[0015] 2. The present invention uses a visual detection component to switch between a shock-absorbing damping connection and a rigid clamping connection for the visual image sensor. Under normal conditions, the shock-absorbing damping sleeve isolates the high-frequency micro-vibrations of the bridge deck to ensure image clarity. When crossing the cable, it automatically switches to a rigid connection to eliminate elastic secondary swaying and impact residual vibration, so that the detection accuracy in the cable crossing area is consistent with that in the normal area.

[0016] 3. This invention uses the combination of a flip plate and an angle sensor in the sling detection assembly to detect the sling, confirm whether the sling has been encountered, and then provide feedback to control the action of the multi-position connection assembly.

[0017] 4. The present invention, through the setting of the plug-in locking component, connects the two side support plates into an integral simply supported beam structure after unfolding through the end plug-in locking component, which increases the mid-span bending stiffness by more than 3 times and reduces the arm end flutter amplitude by 70%, thereby reducing the interference of vibration on the imaging quality of the visual inspection component from the source. Attached Figure Description

[0018] Figure 1 This is a top-view three-dimensional structural diagram of the present invention in use. Figure 2 This is a bottom-view three-dimensional structural diagram of the present invention in use. Figure 3 This is a schematic diagram of the overall three-dimensional structure of the present invention; Figure 4 This is a front view structural diagram of the present invention; Figure 5 This is a three-dimensional structural schematic diagram of the support component of the present invention; Figure 6 This is a three-dimensional structural diagram of the multi-position connection component of the present invention; Figure 7 yes Figure 6 A schematic diagram of the frontal sectional view of the structure; Figure 8 This is a three-dimensional structural schematic diagram of the sling detection component of the present invention; Figure 9 This is a three-dimensional cross-sectional view of the visual inspection component of the present invention; Figure 10 This is a front cross-sectional view of the plug-in locking assembly of the present invention.

[0019] Explanation of reference numerals in the attached drawings: 1. Moving trolley; 2. Support plate; 3. Support assembly; 31. Fixing plate; 32. Groove; 33. Support plate; 331. Connecting plate; 332. Bolt; 34. Torque motor; 4. Multi-position connection assembly; 41. Mounting housing; 42. Mounting base; 43. Electric actuator one; 44. Push plate one; 45. Locking rod; 46. Locking groove; 47. Positioning housing; 48. Electric actuator two; 49. Push plate two; 410. Insertion rod; 411. Insertion groove; 412. Insertion hole; 5. Lifting sling Detection assembly; 51. Extension plate; 52. Notch; 53. Rotating shaft; 54. Flip plate; 55. Torque return spring; 56. Angle sensor; 6. Vision inspection assembly; 61. Positioning cylinder; 62. Shock-absorbing damping sleeve; 63. Mounting post; 64. Vision image sensor; 65. Outer expanded round shell; 66. Electric push rod three; 67. Arc-shaped extrusion plate; 7. Insertion locking assembly; 71. Embedding slot; 72. Screw drive mechanism; 73. Moving plate; 74. Insertion rod; 75. Insertion slot; 76. Conical expansion slot. Detailed Implementation

[0020] The technical solution of the present invention will now be clearly and completely described in conjunction with the accompanying drawings and embodiments.

[0021] like Figures 1-4 The device shown is a concrete bridge underside crack detection device, comprising two symmetrically arranged mobile trolleys 1 and a controller for overall machine control. Each mobile trolley 1 is equipped with a drive motor, encoder, and braking unit, enabling it to move at a constant speed along the longitudinal direction of the bridge and provide real-time position data feedback. A support plate 2 is fixed to the upper end of each mobile trolley 1, serving as the mounting base for the upper structure. The device also includes two sets of support components 3, two sets of multi-position connection components 4, two sets of cable detection components 5, and multiple vision detection components 6.

[0022] In practical use, in this embodiment, a mobile trolley 1 drives multiple vision inspection components 6 to move on the bottom surface of a concrete bridge, thereby detecting and providing feedback on cracks on the bottom surface of the bridge. The support component 3 supports the vision inspection components 6 and can flip the support end, allowing the vision inspection components 6 to quickly flip to the bottom surface of the bridge and enter the inspection station. When passing through the sling, the multi-position connection component 4 can automatically open a channel and ensure connection stability, allowing the sling to pass through without manual disassembly and assembly, thus improving inspection efficiency. The sling detection component 5 automatically confirms whether a sling is encountered and then provides feedback to control the action of the multi-position connection component 4.

[0023] like Figure 1 and Figure 5 As shown, further, in this embodiment, the supporting component 3 includes a vertically arranged fixed plate 31, the lower end of the fixed plate 31 is provided with a groove 32, and a supporting plate 33 is rotatably connected in the groove 32 through a connecting shaft. The supporting plate 33 and the connecting shaft are fixedly connected, and one end of the connecting shaft is connected to a torque motor 34. The torque motor 34 drives the supporting plate 33 to switch between a folded storage state and a horizontal working state.

[0024] In practical use, in this embodiment, the support plate 33 supports the visual inspection component 6 for installation. During the transportation and transfer phase, the torque motor 34 drives the support plate 33 to flip outward and upward, so that the support plate 33 and the fixed plate 31 are in a folded and stored state that is close to the same straight line, reducing the overall size of the equipment and facilitating loading and transportation. During the on-site deployment phase, the mobile trolley 1 is parked on both sides of the bridge edge, and the torque motor 34 is started to drive the support plate 33 to flip around the connecting shaft until the support plate 33 is in a horizontal state and located directly below the bottom surface of the concrete bridge for subsequent inspection actions. This avoids the problem that an excessively long robotic arm would obstruct the rapid installation of the visual inspection component 6 to the inspection station, achieving rapid installation and positioning, and ensuring the rapid progress of the inspection work.

[0025] like Figure 5 As shown, in this embodiment, the support plate 33 is composed of multiple connecting plates 331 spliced ​​together, and two adjacent connecting plates 331 are detachably and fixedly connected by bolts 332 to adapt to bridges of different widths.

[0026] In practical use, this embodiment uses a modular splicing design to select an appropriate number of connecting plates 331 based on the actual span of the concrete bridge, and multiple connecting plates 331 are assembled into a support plate 33 by bolts 332. This can be adapted to concrete bridges with different spans. Furthermore, multiple connecting plates 331 can be disassembled during transportation to facilitate transport. The bolts 332 are made of high-strength galvanized material to meet outdoor corrosion protection and load-bearing requirements.

[0027] like Figure 1 , Figure 6 and Figure 7 As shown, further, in this embodiment, the multi-position connection component 4 is fixedly disposed between the support plate 2 and the support component 3, and is used to realize the detachable connection between the mobile trolley 1 and the support component 3, and to continuously pass through the bridge sling by unlocking and avoiding at each point. The multi-position connection component 4 includes a mounting shell 41 fixed to the upper end of the support plate 2 and a mounting base 42 fixed to the upper end of the fixed plate 31. Seven electric actuators 43 are fixedly fixed at equal intervals along the longitudinal direction on the inner wall of the mounting shell 41. A push plate 44 is fixed to the moving end of the electric actuator 43. Two locking rods 45 are symmetrically fixed on the side of the push plate 44 away from the electric push rod 43. The side wall of the mounting base 42 is provided with locking grooves 46 that correspond to the locking rods 45 and are inserted into them one by one. The front end of the locking rod 45 is tapered and is set as a tapered guide section with a tapered angle of 15°. It is used for automatic guidance and centering during the insertion process. The interval between two adjacent sets of locking rods 45 is greater than the gap between the mounting shell 41 and the mounting base 42, that is, greater than the diameter of the sling. This ensures that the sling can pass through completely when only one set of locking rods 45 retracts to make room. The mounting base 42 is fixed with positioning shells 47 at both the upper and lower ends. The horizontal part of the positioning shell 47 is equidistantly fitted with multiple electric push rods 48 in the vertical direction. The moving end of the electric push rod 48 is fixed with a push plate 49. Multiple insertion rods 410 are fixed on the side of the push plate 49 away from the electric push rod 48. The surface of the mounting base 42 is provided with insertion grooves 411 that match and insert with the insertion rods 410. The rod wall of the locking rod 45 is provided with insertion holes 412 that match and insert with the insertion rods 410.

[0028] In actual use, in this embodiment, the initial connection between the mounting shell 41 and the mounting base 42 is achieved through the insertion and engagement of the locking rod 45 and the locking groove 46. The insertion rod 410 engages with the insertion groove 411 and the insertion hole 412 to limit and lock the end of the locking rod 45. The tapered guide section at the front end of the locking rod 45 utilizes the inclined sliding effect to achieve automatic compensation for the connection. Even if there is a slight deviation of ±2mm between the axis of the locking rod 45 and the locking groove 46, the radial component of the contact of the tapered surface can force the mounting base 42 to fine-tune its position, achieving precise insertion and avoiding jamming. At the same time, the tapered structure can reduce lateral force and prevent the rod from bending and wearing due to long-term vibration. The vertical insertion of the insertion rod 410 and the insertion hole 412 can form an axial mechanical limit for the locking rod 45. In the normal connection state, all electric actuators 43 are in the extended state, locking rod 45 is fully inserted into locking groove 46, electric actuator 48 extends synchronously, and insertion rod 410 passes through insertion groove 411 and is inserted into insertion hole 412 of locking rod 45, forming a double locking structure, which firmly connects mounting shell 41 and mounting base 42 into one piece. During actual cable movement, when the sling reaches the position of the first locking rod 45, the corresponding electric actuator 48 retracts first, causing the insertion rod 410 to exit the insertion hole 412 and insertion slot 411, releasing the axial restriction on the locking rod 45. Then, the electric actuator 43 retracts, and through the push plate 44, it causes the locking rod 45 to be pulled out of the locking slot 46, making room for the sling to pass. The sling continues to move, passing through each subsequent group of locking rods 45 in sequence. Each group of locking rods 45 operates in sequence according to the above process. After the sling passes through a certain locking point, the electric actuator 43 immediately pushes the locking rod 45 to re-insert into the locking slot 46, and the electric actuator 48 simultaneously pushes the insertion rod 410 to complete the locking. Throughout the process, only one group of locking rods 45 is in the unlocked state, while the other points continue to bear the load.

[0029] like Figure 8 As shown, further, in this embodiment, the sling detection component 5 is fixed to the front end of the multi-position connection component 4 in the direction of travel, and is used to identify and detect slings. The sling detection component 5 includes two extension plates 51 respectively fixed to the front end of the mounting base 42 and the mounting shell 41. The front end of the extension plate 51 is provided with a notch 52. A flip plate 54 is rotatably connected in the notch 52 through a rotating shaft 53. A torque return spring 55 is fixed between the flip plate 54 and the extension plate 51 and sleeved on the outside of the rotating shaft 53. In the natural state, the torque return spring 55 keeps the flip plate 54 in the initial state perpendicular to the extension plate 51. An angle sensor 56 is installed on the outer wall of the extension plate 51. The input end of the angle sensor 56 is fixedly connected to one end of the rotating shaft 53. The angle sensor 56 is used to collect the deflection angle of the flip plate 54.

[0030] In actual use, during the movement of the mobile trolley 1 in this embodiment, the flip plate 54 contacts the sling before the locking rod 45. As the mobile trolley 1 continues to move forward, the sling pushes the flip plate 54 to deflect around the rotating shaft 53, compressing the torque return spring 55. At the same time, the rotating shaft 53 drives the input end of the angle sensor 56 to rotate synchronously. The angle sensor 56 transmits the deflection signal to the controller. After the sling has completely passed the flip plate 54, the torque return spring 55 drives the flip plate 54 to return to its initial position. The purely mechanical contact structure realizes the presence recognition of the sling, without the need for an additional visual recognition module. It is not affected by insufficient lighting under the bridge, dust, water mist, or other environmental factors, and its outdoor reliability is better than photoelectric and visual detection solutions.

[0031] like Figure 9As shown, further, in this embodiment, the plurality of visual inspection components 6 are installed at lateral intervals on the upper surface of the support component 3 to collect images of the bottom surface of the concrete bridge and identify cracks. The visual inspection component 6 includes a positioning cylinder 61 fixed to the upper end of the support plate 33. The inner wall of the positioning cylinder 61 is fixed with a mounting column 63 by a shock-absorbing damping rubber sleeve 62. A visual image sensor 64 is fixed to the top of the mounting column 63. The visual image sensor 64 adopts a 20-megapixel area array industrial camera and is equipped with a coaxial supplementary light source.

[0032] In actual use, in this embodiment, the visual image sensor 64 detects and provides feedback on cracks on the bottom surface of the bridge. During normal uniform speed detection, the mounting column 63 is suspended and supported inside the positioning cylinder 61 by the shock-absorbing damping sleeve 62. The high-frequency micro-vibrations (above 50Hz) transmitted to the support plate 33 due to uneven bridge surface and wheel vibration are damped and attenuated by the shock-absorbing damping sleeve 62, and the amplitude transmitted to the visual image sensor 64 is reduced by more than 90%, ensuring that the visual image sensor 64 can provide clear images and accurately identify the details of the micro-cracks.

[0033] like Figure 9 As shown, further, in this embodiment, an outerly expanding shell 65 is integrally connected to the upper outer side of the positioning cylinder 61. Multiple electric push rods 66 are evenly inserted into the side wall of the outerly expanding shell 65 along the circumference. An arc-shaped extrusion plate 67 is fixed to the moving end of the electric push rod 66. The arc of the arc-shaped extrusion plate 67 matches the arc of the outer wall of the mounting column 63.

[0034] In actual use, in this embodiment, when the sling detection component 5 detects the sling, the controller issues a locking command. The three electric push rods 66 extend synchronously, pushing the arc-shaped extrusion plate 67 to evenly clamp the mounting column 63 from the circumference. Under the extrusion force, the mounting column 63 and the positioning cylinder 61 are rigidly engaged. At this time, the visual image sensor 64 and the support plate 33 are rigidly connected without relative elastic displacement. After the sling crossing is completed and the vibration is sufficiently attenuated, the electric push rods 66 retract and return to the normal damping state. The three sets of arc-shaped extrusion plates 67 are evenly distributed circumferentially and move synchronously. The clamping force is evenly distributed radially, which will not cause the mounting column 63 to shift to one side, ensuring that the optical axis direction of the visual image sensor 64 does not shift before and after locking.

[0035] like Figure 4 and Figure 10As shown, further, in this embodiment, the plug-in locking assembly 7 is installed at the opposite ends of the two sets of support assemblies 3, and is used to lock the free ends of the two sets of support assemblies 3 together into an integral structure. The plug-in locking assembly 7 includes an insert groove 71 opened at the end of one of the connecting plates 331. A screw drive mechanism 72 is installed on the inner wall of the insert groove 71. The screw drive mechanism 72 consists of a servo motor, a screw, and a nut seat. A moving plate 73 is fixed on the nut seat of the screw drive mechanism 72. Four parallel plug-in rods 74 are fixed on the side wall of the moving plate 73. A through hole is opened at the end of the connecting plate 331 for the plug-in rods 74 to pass through. An insert groove 75 is opened at the end of the other connecting plate 331 to match and insert the plug-in rods 74. The outer port of the insert groove 75 is provided with a tapered expansion groove 76 with a tapered angle of 30°, which is used to guide the plug-in rods 74 to automatically align and insert.

[0036] In actual use, after both support plates 33 in this embodiment are unfolded to a horizontal state, the controller activates the screw drive mechanism 72. The servo motor drives the screw to rotate, causing the nut seat and the moving plate 73 to move forward. The four insertion rods 74 extend synchronously from the guide through holes and approach the insertion slot 75 of the other support plate 33. The front end of the insertion rod 74 first contacts the inclined surface of the conical expansion groove 76. If there is a misalignment between the two support plates 33, the insertion rod 74 will slide along the conical surface, forcing the two support plates 33 to adjust their positions slightly to achieve automatic alignment. Then, the insertion rod 74 smoothly inserts into the insertion slot 75 to complete the docking and locking. After the test is completed, the screw drive mechanism 72... 2. Reverse rotation drives the plug rod 74 to retract, releasing the connection. After connection, the two side support plates 33 form a simply supported beam structure with support at both ends. The mid-span bending stiffness is more than 3 times higher than that of a single-sided cantilever structure, and the natural frequency of the arm end is significantly improved. It can effectively avoid the main frequency range of bridge deck load vibration, and the flutter amplitude is reduced by 70%. Moreover, the conical expansion groove 76 can accommodate a connection deviation of ±5mm, reducing the alignment accuracy requirements of the two side moving trolleys 1 during on-site deployment. There is no need for repeated manual adjustments, improving deployment efficiency. The four plug rods 74 extend synchronously and are evenly distributed. After connection, the shear force is evenly transmitted, avoiding the stress concentration problem of single rod connection, and the load-bearing capacity is stronger.

[0037] The operation process of this embodiment is as follows: two mobile trolleys 1 are parked on the sidewalks or emergency lanes on both sides of the concrete bridge, the corresponding number of connecting plates 331 are assembled according to the width of the bridge, the total length of the support plate 33 is adjusted, the torque motor 34 is started to flip the support plate 33 to the horizontal, so that the visual image sensor 64 faces the bottom of the bridge, and the controller controls the plug-in locking assembly 7 to complete the docking and locking of the ends of the support plates 33 on both sides. The controller controls the mobile trolley 1 to move at a set speed (normal detection speed) along the longitudinal direction of the bridge at a constant speed. The visual image sensor 64 continuously acquires images of the concrete surface at the bottom of the beam at a fixed frame rate. The crack outline is extracted by the crack recognition algorithm (refer to the conventional algorithm), and the width, length, direction and location information of the crack are calculated. During this stage, the visual detection component 6 is in a damping state. The high-frequency micro-vibration of the bridge deck is effectively isolated by the damping rubber sleeve 62 to ensure the clarity of the image. After the flip plate 54 of the sling detection component 5 contacts the sling, the angle sensor 56 feeds back a deflection signal to the controller. The controller controls the moving trolley 1 to decelerate to 1 / 4 of the normal detection speed. At the same time, the electric push rod 66 of the vision detection component 6 moves to switch the vision image sensor 64 to a rigid locking state, ensuring that the vision image sensor 64 is completely rigidly fixed before entering the sling crossing stage. The mobile trolley 1 moves at low speed, and the multi-position connection component 4 unlocks the locking rods 45 one by one in the direction of travel. The sling passes through each locking point in sequence. Each locking rod 45 is immediately reset and locked after the sling passes through. Throughout the process, only one locking structure is released from the load and the connection stiffness does not decrease significantly. After all locking rods 45 have been reset and locked and the vibration has been sufficiently attenuated, the visual inspection component 6 releases the rigid locking and returns to the damping state. The moving trolley 1 accelerates to the normal inspection speed and continues to inspect subsequent road sections to ensure the continuity and accuracy of the crack data of the entire bridge. After all tests are completed, the plug-in locking component 7 is disconnected, the support plate 33 is flipped and folded outward and upward, and the equipment can be moved and removed.

[0038] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A device for detecting cracks on the bottom surface of a concrete bridge, comprising two symmetrically arranged mobile trolleys (1) and a controller for overall machine control, wherein a support plate (2) is fixed to the upper end of each mobile trolley (1), characterized in that, It also includes two sets of support components (3), two sets of multi-position connection components (4), two sets of sling detection components (5) and multiple vision detection components (6); The multi-position connection component (4) is fixedly installed between the support plate (2) and the support component (3) to realize the disengageable connection between the mobile trolley (1) and the support component (3), and to continuously pass through the bridge sling by unlocking and avoiding at each point; The sling detection component (5) is fixed to the front end of the multi-position connection component (4) in the direction of travel and is used to identify and detect slings; Multiple visual inspection components (6) are evenly installed on the upper surface of the support component (3) to collect images of the bottom surface of the concrete bridge and identify cracks; The two sets of support components (3) are connected by a plug-in locking component (7).

2. The device for detecting cracks on the bottom surface of a concrete bridge according to claim 1, characterized in that, The support assembly (3) includes a vertically arranged fixing plate (31). A groove (32) is provided at the lower end of the fixing plate (31). A support plate (33) is rotatably connected in the groove (32) through a connecting shaft. The support plate (33) and the connecting shaft are fixedly connected. One end of the connecting shaft is connected to a torque motor (34). The torque motor (34) drives the support plate (33) to switch between a folded storage state and a horizontal working state.

3. The device for detecting cracks on the bottom surface of a concrete bridge according to claim 2, characterized in that, The support plate (33) is composed of multiple connecting plates (331) spliced ​​together, and two adjacent connecting plates (331) are detachably and fixedly connected by bolts (332).

4. The device for detecting cracks on the bottom surface of a concrete bridge according to claim 2, characterized in that, The multi-position connection assembly (4) includes a mounting shell (41) fixed to the upper end of the support plate (2) and a mounting base (42) fixed to the upper end of the fixing plate (31). The inner wall of the mounting shell (41) is fixed with multiple electric push rods (43) at equal intervals along the longitudinal direction. The moving end of the electric push rod (43) is fixed with a push plate (44). Two locking rods (45) are symmetrically fixed on the side of the push plate (44) away from the electric push rod (43). The side wall of the mounting base (42) is provided with locking grooves (46) that are inserted into the locking rods (45) one by one. The front end of the locking rod (45) is provided with a conical structure for automatic guidance and centering during the insertion process. The interval between two adjacent sets of locking rods (45) is greater than the diameter of the sling, ensuring that the sling can pass completely when only one set of locking rods (45) retracts to make way each time.

5. A device for detecting cracks on the bottom surface of a concrete bridge according to claim 4, characterized in that, The mounting base (42) is fixed with positioning shells (47) at both the upper and lower ends. The horizontal part of the positioning shell (47) is equidistantly fitted with multiple electric push rods (48) in the vertical direction. The moving end of the electric push rod (48) is fixed with a push plate (49). Multiple insertion rods (410) are fixed on the side of the push plate (49) away from the electric push rod (48). The surface of the mounting base (42) is provided with an insertion groove (411) that matches and inserts into the insertion rod (410). The wall of the locking rod (45) is provided with an insertion hole (412) that matches and inserts into the insertion rod (410). The insertion rod (410) cooperates with the insertion groove (411) and the insertion hole (412) to limit and lock the end of the locking rod (45).

6. A device for detecting cracks on the bottom surface of a concrete bridge according to claim 5, characterized in that, The sling detection assembly (5) includes two extension plates (51) fixed to the front end of the mounting base (42) and the mounting shell (41) respectively. The front end of the extension plate (51) is provided with a notch (52). A flip plate (54) is rotatably connected in the notch (52) through a rotating shaft (53). A torque return spring (55) sleeved on the outside of the rotating shaft (53) is fixed between the flip plate (54) and the extension plate (51). An angle sensor (56) is installed on the outer wall of the extension plate (51). The input end of the angle sensor (56) is fixedly connected to one end of the rotating shaft (53). The angle sensor (56) is used to collect the deflection angle of the flip plate (54).

7. A device for detecting cracks on the bottom surface of a concrete bridge according to claim 3, characterized in that, The visual inspection component (6) includes a positioning cylinder (61) fixed to the upper end of the support plate (33). The inner wall of the positioning cylinder (61) is fixed with a mounting column (63) by a shock-absorbing damping rubber sleeve (62). A visual image sensor (64) is fixed to the top of the mounting column (63).

8. A device for detecting cracks on the bottom surface of a concrete bridge according to claim 7, characterized in that, The upper outer side of the positioning cylinder (61) is integrally connected with an expanded circular shell (65). Multiple electric push rods (66) are evenly inserted into the side wall of the expanded circular shell (65) along the circumference. An arc-shaped extrusion plate (67) is fixed to the moving end of the electric push rod (66). The arc of the arc-shaped extrusion plate (67) matches the arc of the outer wall of the mounting column (63).

9. A device for detecting cracks on the bottom surface of a concrete bridge according to claim 3, characterized in that, The plug-in locking assembly (7) includes an insert groove (71) opened at the end of one of the connecting plates (331). A screw drive mechanism (72) is installed on the inner wall of the insert groove (71). A movable plate (73) is fixed on the nut seat of the screw drive mechanism (72). Multiple parallel plug rods (74) are fixed on the side wall of the movable plate (73). A through hole for the plug rods (74) to pass through is opened at the end of the connecting plate (331). The other connecting plate (331) has a plug groove (75) at its end that matches and plugs into the plug rod (74). The outer port of the plug groove (75) has a tapered expansion groove (76) for guiding the plug rod (74) to automatically align and insert.

Images