A road and bridge pavement crack detection device

Abstract

The present invention relates to a road and bridge pavement crack detection device applied to the technical field related to crack detection. It can simultaneously identify surface cracks and slight depressions on the road surface. When the road surface is flat and there is no slight depression, the bottoms of multiple concave measuring units will be on a straight line. At this time, the data of the two laser rangefinders tend to remain unchanged. When there is a slight depression, the bottom of the concave measuring unit at the depression will be lower, resulting in the corresponding light display board moving down. At this time, the data of one of the laser rangefinders will decrease. At this time, the main camera and the sub-camera can be controlled to take pictures simultaneously, and the two picture-taking information can be combined into a set of data, thereby realizing the online marking of slight depressions. At the same time, color powder can fall at the sub-marking tube to mark the road surface depression. Compared with the existing technology that only detects by taking pictures, the probability of detecting hidden cracks is greatly improved, and thus the impact of hidden cracks on traffic and the road life is effectively reduced.

Description

Technical Field

[0001] A road and bridge pavement crack detection device involved in the present invention, in particular, a road and bridge pavement crack detection device applied to the technical field related to crack detection. Background Art

[0002] A pavement crack refers to a crack that appears on the surface layer or base layer of the pavement along a certain direction. Pavement cracks are one of the main causes of traffic accidents and vehicle driving losses. If not treated in time, it will lead to further pavement damage and even traffic accidents. Therefore, timely pavement crack detection and treatment are very important.

[0003] During road maintenance, some already existing large cracks are easy to detect, while some small cracks are difficult to detect in time, resulting in untimely repair. Subsequently, they are likely to develop into large cracks, which not only affect traffic but also the service life of the road, and the subsequent maintenance cost also increases invisibly.

[0004] In the prior art to solve this problem, the detection methods in patents such as a detection device for detecting pavement cracks disclosed in Chinese Patent CN117604863 and a pavement crack detection device and detection method based on a smart phone disclosed in CN108801151A all adopt the method of taking pictures of the pavement surface to obtain image information, and then through computer-aided technology, data processing is carried out on the image to judge small cracks; however, taking pictures to obtain image information can only obtain the image information of the pavement surface layer, and has a good detection effect on surface layer cracks, but it is difficult to identify slight depressions on the road surface. And there are often some small cracks inside the slight depression. If not repaired in time, it is easy to cause regional collapse of the depression. Summary of the Invention

[0005] In view of the above prior art, the technical problem to be solved by the present invention is that the method of detecting the pavement by obtaining image information in the prior art is likely to ignore the cracks that may exist inside the slight depression of the pavement.

[0006] To solve the above problems, the present invention provides a road and bridge pavement crack detection device, including a detection trolley. A top plate is fixedly connected to the lower end of the detection trolley. L-shaped side plates are fixedly connected to the left and right lower ends of the top plate. A marking unit is installed on the L-shaped side plates. The marking unit includes a double-chamber powder box fixed to the upper end of the L-shaped side plate and a main marking pipe and a sub-marking pipe fixedly connected to the lower end of the double-chamber powder box. The main marking pipe and the sub-marking pipe are arranged side by side in the front and rear, and both penetrate through the L-shaped side plate and extend below the L-shaped side plate. The interior of the double-chamber powder box is divided into two chambers, and different colored powders are filled in the two chambers respectively. A surface layer crack detection unit is arranged at the lower end of the top plate. The surface layer crack detection unit includes a main camera fixedly connected to the lower end of the top plate and a plurality of uniformly distributed concave detection units;

[0007] A hidden crack detection unit is jointly arranged between multiple concave measuring units and two L-shaped side plates. The hidden crack detection unit includes two mounting plates respectively fixedly connected to the lower ends of the two L-shaped side plates, multiple light-emitting plates respectively fixedly connected to the outer ends of the multiple concave measuring units, and a secondary camera fixedly connected to the top of the top plate. Laser rangefinders are fixedly connected to one ends of the two mounting plates close to each other.

[0008] The concave measuring unit includes a positioning rod fixedly connected to the top plate, a follower rod fixedly connected to the lower end of the positioning rod, a double-arm frame fixedly connected to the lower end of the follower rod, and a detection wheel rotatably connected between the two arms of the double-arm frame.

[0009] In the above road and bridge pavement crack detection device, through the arrangement of the surface crack detection unit and the hidden crack detection unit, the identification of surface cracks and slight depressions can be realized simultaneously. Compared with the method of taking pictures to obtain road surface image information in the prior art, the probability of detecting hidden cracks is greatly improved, and thus the influence of hidden cracks on traffic and the service life of the road is effectively reduced.

[0010] As a further improvement of the present application, the main camera and the secondary camera are arranged side by side, and both are located on the side of the multiple concave measuring units away from the traveling direction of the detection trolley. The shooting end of the main camera faces downward, and the shooting end of the secondary camera faces the multiple concave measuring units.

[0011] As a further improvement of the present application, when the multiple concave measuring units are not stressed, the lower end of the concave measuring unit is lower than the lower end of the wheel hub of the detection trolley.

[0012] As a further improvement of the present application, the light-emitting plate includes two connecting rods fixedly connected between the double-arm frames, a frame fixedly connected to the ends of the two connecting rods, and a light-transmitting sheet fixedly embedded in the center of the frame. The upper and lower ends of the multiple light-transmitting sheets are both semicircular.

[0013] As a further improvement of the present application, the two laser rangefinders are arranged in a staggered manner, and when the multiple concave measuring units and the wheel hubs of the detection trolley are in contact with the horizontal ground synchronously, the laser beams emitted by the two laser rangefinders respectively pass through the centers of the two semicircles on the light-transmitting sheet.

[0014] As another improvement of the present application, multiple light guide bars are fixedly embedded inside the light-transmitting sheet. Both ends of the multiple light guide bars extend to the surface of the light-transmitting sheet, and the connection line between the midpoints of the ends of the multiple light guide bars coincides with the vertical center line of the light-transmitting sheet.

[0015] As a supplement to another improvement of the present application, the multiple light guide bars are all in a folded line structure and are made of a transparent light guide material. The parts of the multiple light guide bars located inside the light-transmitting sheet do not overlap with each other, and the two ends of the same light guide bar are symmetrical about the horizontal center line of the light-transmitting sheet.

[0016] As another improvement of the present application, the follower rod includes an outer moving shell fixedly connected to the double-arm bracket, an I-shaped rod fixedly connected to the positioning rod, and an elastic member fixedly connected between the lower end of the I-shaped rod and the inner bottom end of the outer moving shell. The lower end of the I-shaped rod extends into the inner part of the outer moving shell, and an indicating unit is connected between the outer moving shell and the I-shaped rod.

[0017] As a supplement to another improvement of the present application, the indicating unit includes an annular light strip installed at the outer end of the outer moving shell, a moving contact piece and a fixed contact piece electrically connected to the annular light strip, and an outer attachment layer wrapped around the outer end of the middle part of the I-shaped rod. The moving contact piece is fixedly inlaid at the outer end of the bottom of the I-shaped rod, the fixed contact piece is fixedly inlaid on the inner wall of the mouth of the outer moving shell, the inside of the outer attachment layer is filled with saturated air, and the lower end of the outer attachment layer is located inside the outer moving shell. The outer attachment layer is made of an elastic sealing material.

[0018] As a supplement to another improvement of the present application, when the concave measuring unit is not stressed, the moving contact piece is located below the fixed contact piece. When the concave measuring unit is flush with the bottom of the detection trolley wheel hub, the fixed contact piece corresponds to and contacts the moving contact piece. When the two contact, the annular light strip is turned on.

[0019] In summary, the recognition of surface cracks and slight depressions on the road surface can be realized simultaneously. When the road surface is flat and there is no slight depression, the bottoms of multiple concave measuring units will be on a straight line. At this time, the data of the two laser rangefinders tend to remain unchanged. When there is a slight depression, the bottom of the concave measuring unit at the depression will be lower, resulting in the corresponding light display board moving down. At this time, the data of one of the laser rangefinders will decrease. At this time, the main camera and the sub-camera can be controlled to take pictures simultaneously, and the two picture-taking information can be combined into a set of data, so as to realize the online marking of the slight depression. At the same time, toner can fall at the sub-marking tube to realize the marking of the road surface depression. Compared with the prior art that only detects by taking pictures, the probability of detecting hidden cracks is greatly improved, and thus the influence of hidden cracks on traffic and the road life is effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is the front view of the first embodiment of the present application;

[0021] Figure 2 is a partial top-down perspective view of the first embodiment of the present application;

[0022] Figure 3 is a partial bottom-up perspective view of the first embodiment of the present application;

[0023] Figure 4 is the perspective view of the concave measuring unit of the first embodiment of the present application;

[0024] Figure 5 is the perspective view of a part of the hidden crack detection unit of the first embodiment of the present application;

[0025] Figure 6 Schematic diagram of the principle of the hidden crack detection unit of the first embodiment of the present application for detecting the sunken area;

[0026] Figure 7 Front view of the light-emitting plate of the second embodiment of the present application;

[0027] Figure 8 Front view of the follower rod when not under force in the third embodiment of the present application;

[0028] Figure 9 Front view of the follower rod when the concave detection unit is horizontal with the lower end of the vehicle body wheel hub in the third embodiment of the present application;

[0029] Figure 10 Front view of the corresponding follower rod when there is a local protrusion on the ground in the third embodiment of the present application.

[0030] Description of the reference numerals in the figure:

[0031] 1 Detection trolley, 21 Top plate, 22 L-shaped side plate, 31 Double-chamber powder box, 32 Main marking tube, 33 Sub-marking tube, 4 Concave detection unit, 41 Positioning rod, 42 Follower rod, 43 Double-arm bracket, 44 Detection wheel, 421 Outer moving shell, 422 I-shaped rod, 423 Elastic member, 51 Outer attachment layer, 52 Ring-shaped light strip, 531 Moving contact piece, 532 Fixed contact piece, 61 Main camera, 62 Sub-camera, 7 Light-emitting plate, 71 Connecting rod, 72 Frame, 73 Translucent sheet, 8 Mounting plate, 801 Laser rangefinder, 9 Light guide bar. Specific embodiments

[0032] The following will describe in detail the three embodiments of the present application with reference to the accompanying drawings.

[0033] The first embodiment:

[0034] Figure 1-2Shown is a road and bridge pavement crack detection device, including a detection trolley 1. A top plate 21 is fixedly connected to the lower end of the detection trolley 1. L-shaped side plates 22 are fixedly connected to the left and right lower ends of the top plate 21. A marking unit is installed on the L-shaped side plates 22. The marking unit includes a double-chamber powder box 31 fixed to the upper end of the L-shaped side plate 22, a main marking tube 32 and a secondary marking tube 33 fixedly connected to the lower end of the double-chamber powder box 31. The main marking tube 32 and the secondary marking tube 33 are arranged side by side front and back, and both penetrate through the L-shaped side plate 22 and extend below the L-shaped side plate 22. The interior of the double-chamber powder box 31 is divided into two chambers, and different colored powders are filled in the two chambers respectively. A surface crack detection unit is arranged at the lower end of the top plate 21. The surface crack detection unit includes a main camera 61 fixedly connected to the lower end of the top plate 21 and a plurality of evenly distributed concave detection units 4. During monitoring, the detection trolley 1 moves along the road surface. At this time, the main marking tubes 32 on the two marking units will slowly drop the colored powder, thereby marking the traveling track of the detection trolley 1. Thus, when the detection trolley 1 reciprocates on the road surface to obtain road surface images, it can relatively comprehensively obtain road surface information, and it is not easy to have repeated acquisition or missed acquisition of repeated road surface image information, thereby effectively ensuring the comprehensiveness and efficiency of crack detection.

[0035] When none of the plurality of concave detection units 4 is under force, the lower end of the concave detection unit 4 is lower than the lower end of the wheel hub of the detection trolley 1. Thus, when the concave detection unit 4 and the detection trolley 1 are in contact with the horizontal road surface at the same time, the concave detection unit 4 will be pushed upward and be in a compressed state. During its movement along with the detection trolley 1, when there is a local depression on the road surface, the corresponding concave detection unit 4 will move downward due to the loss of support, and thus its position will change longitudinally, which will drive the light display board 7 to change its position, making the relative position between it and the two laser rangefinders 801 change. Furthermore, it will cause differences in the data on the two laser rangefinders 801, thereby realizing the identification of road surface depressions while obtaining road surface image information. Compared with the prior art, the situation of hidden cracks being ignored is reduced, and the road surface can be effectively maintained in a timely manner. Compared with the prior art, the impact of hidden cracks on traffic and the road life is greatly reduced.

[0036] A hidden crack detection unit is jointly arranged between the plurality of concave detection units 4 and the two L-shaped side plates 22. The hidden crack detection unit includes two mounting plates 8 respectively fixedly connected to the lower ends of the two L-shaped side plates 22, a plurality of light display boards 7 respectively fixedly connected to the outer ends of the plurality of concave detection units 4, and a secondary camera 62 fixedly connected to the top of the top plate 21. Laser rangefinders 801 are fixedly connected to one end of each of the two mounting plates 8 close to each other;

[0037] The concave measuring unit 4 includes a positioning rod 41 fixedly connected to the top plate 21, a follower rod 42 fixedly connected to the lower end of the positioning rod 41, a double-arm frame 43 fixedly connected to the lower end of the follower rod 42, and a detection wheel 44 rotatably connected between the two arms of the double-arm frame 43. In this embodiment, the follower rod 42 is an elastic telescopic rod. When the detection wheel 44 contacts the ground, under the action of the follower rod 42, as Figure 6 , in the figure, a represents the laser beam. The detection wheel 44 can move up and down with the bumps and depressions of the ground, thereby achieving the effect of changing the relative positions of the laser rangefinder 801 and the light display board 7, promoting the differentiation of the data of the two laser rangefinders 801, and then realizing the recognition of slight depressions on the road surface.

[0038] The main camera 61 and the auxiliary camera 62 are arranged side by side, and both are located on the side of the plurality of concave measuring units 4 away from the traveling direction of the detection trolley 1. The shooting end of the main camera 61 faces downward and is mainly used to shoot the image information of the road surface. The shooting end of the auxiliary camera 62 faces the plurality of concave measuring units 4. When the data of the two laser rangefinders 801 differ greatly, on the one hand, the auxiliary marking tube 33 releases toner to mark the road surface, which is convenient for the staff to conduct targeted re-inspection of the cracks at the depression and perform effective maintenance in a timely manner. On the other hand, the auxiliary camera 62 starts to shoot the image information at the plurality of light display boards 7 at this time, and takes the image information and the image information obtained by the main camera 61 at this time as a set of data to achieve online marking, which is convenient for subsequent computer analysis of the cracks.

[0039] As Figure 5 and Figure 6 , the light display board 7 includes two connecting rods 71 fixedly connected between the double-arm frames 43, a frame 72 fixedly connected to the ends of the two connecting rods 71, and a light-transmitting sheet 73 fixedly embedded in the center of the frame 72. The upper and lower ends of the plurality of light-transmitting sheets 73 are semicircles. The two laser rangefinders 801 are arranged in a staggered manner. When the plurality of concave measuring units 4 and the wheels of the detection trolley 1 are in contact with the horizontal ground synchronously, the laser beams emitted by the two laser rangefinders 801 respectively pass through the centers of the two semicircles on the light-transmitting sheet 73, so that the laser beams emitted by the two laser rangefinders 801 at this time can pass through the plurality of light display boards 7 and reach the opposite mounting plate 8. When there is a local depression, the detection wheel 44 moves downward and drives the light display board 7 to move downward, so that the laser of the upper laser rangefinder 801 gradually separates from the light-transmitting sheet 73 and irradiates on the frame 72, thereby being intercepted by the frame 72, making its data significantly different from that of the other laser rangefinder 801; when there is a local protrusion, the concave measuring unit 4 moves upward and drives the light display board 7 to move upward, so that the laser of the lower laser rangefinder 801 irradiates on the frame 72, and the data difference will also be realized. According to the laser rangefinder 801 with the reduced data, it can be judged whether the road surface is concave or convex.

[0040] It should be noted that solenoid valves are provided on both the main marking tube 32 and the secondary marking tube 33. The solenoid valve on the main marking tube 32 is normally open when the detection trolley 1 is moving, and closes when the detection trolley 1 stops moving. The solenoid valve on the secondary marking tube 33 is normally closed and opens when there is a significant difference in the data of the two laser rangefinders 801. When the road surface has a depression, the secondary marking tube 33 can drop colored powders of different colors, thereby marking the possible depression on the road surface for subsequent road maintenance.

[0041] In addition, when not in contact with the ground, the distance difference between the lower end of the concave measuring unit 4 and the lower end of the wheels of the detection trolley 1 is greater than the radius of the end of the light-transmitting sheet 73. Thus, during the detection process, the concave measuring unit 4 can tolerate the normal undulations of the road surface, improving the accuracy of detection.

[0042] In the above road and bridge pavement crack detection device, through the settings of the surface crack detection unit and the hidden crack detection unit, the identification of surface cracks and slight depressions can be achieved simultaneously. Compared with the method of taking pictures to obtain road surface image information in the prior art, the probability of detecting hidden cracks is greatly increased, thereby effectively reducing the impact of hidden cracks on traffic and the service life of the road.

[0043] The second implementation mode:

[0044] Based on the first implementation mode, the light guide bars 9 can be selectively set according to actual needs, and the rest is the same as the first implementation mode.

[0045] Figure 7 As shown, a plurality of light guide bars 9 are fixedly embedded inside the light-transmitting sheet 73. Both ends of the plurality of light guide bars 9 extend to the surface of the light-transmitting sheet 73, and the connection line between the midpoints of the ends of the plurality of light guide bars 9 coincides with the vertical midline of the light-transmitting sheet 73. The plurality of light guide bars 9 are all in a folded line structure and are made of transparent light guide materials. The parts of the plurality of light guide bars 9 located inside the light-transmitting sheet 73 do not overlap each other, and the two ends of the same light guide bar 9 are symmetric about the horizontal midline of the light-transmitting sheet 73.

[0046] It should be noted that in this embodiment, the laser beams of the two laser rangefinders 801 can be set to different colors. When the road surface is in a sunken or convex condition, after the light display board 7 is displaced, the light beams emitted by the laser rangefinders 801 will be misaligned with the center of the end of the light-transmitting sheet 73. At this time, the light beam of one of the laser rangefinders 801 will irradiate on the light guide bar 9 and conduct along the light guide bar 9, causing the entire light guide bar 9 to emit light, and color bars will appear on the light display board 7 at the convex or concave part. And according to the color of the light emitted by the light guide bar 9, it can be determined which laser rangefinder 801's light beam irradiates on the light-transmitting sheet 73, so that the abnormal light display board 7 can be directly seen in the image information obtained by the auxiliary camera 62, which is convenient for the staff to quickly locate and determine the abnormal depression or abnormal convexity of the road surface.

[0047] Among them, the diameter of the end of the light guide bar 9 is 3-5 times that of the middle part of the light guide bar 9. The distances between the ends of the multiple light guide bars 9 are relatively close to each other, and the distance between them is equivalent to the diameter of the middle part of the light guide bar 9. When the light-transmitting sheet 73 and the laser rangefinder 801 have a relative displacement and approach the light guide bar 9, one of the light guide bars 9 can always be lit. Figure 7 For clear display, the drawn relative intervals are relatively large, only for illustration.

[0048] The third embodiment:

[0049] Based on the first embodiment, this embodiment further improves the follower rod 42, and the rest is the same as the first embodiment.

[0050] Figure 8 As shown, the follower rod 42 includes an outer moving shell 421 fixedly connected to the double-arm frame 43, an I-shaped rod 422 fixedly connected to the positioning rod 41, and an elastic member 423 fixedly connected between the lower end of the I-shaped rod 422 and the inner bottom end of the outer moving shell 421. The lower end of the I-shaped rod 422 extends into the outer moving shell 421. An indicating unit is connected between the outer moving shell 421 and the I-shaped rod 422. The indicating unit includes a circular light strip 52 installed at the outer end of the outer moving shell 421, a moving contact piece 531 and a fixed contact piece 532 electrically connected to the circular light strip 52, and an outer attachment layer 51 wrapped around the outer end of the middle part of the I-shaped rod 422. The moving contact piece 531 is fixedly embedded at the outer end of the bottom of the I-shaped rod 422, the fixed contact piece 532 is fixedly embedded on the inner wall of the mouth of the outer moving shell 421, the outer attachment layer 51 is filled with saturated air inside, and the lower end of the outer attachment layer 51 is located inside the outer moving shell 421. The outer attachment layer 51 is made of an elastic sealing material.

[0051] As Figure 8 , when the concave measuring unit 4 is not stressed, the moving contact piece 531 is located below the fixed contact piece 532, and at this time, the corresponding situation of the road surface depression occurs; as Figure 9, when the concave measuring unit 4 is flush with the bottom of the wheel hub of the detection trolley 1, the fixed contact piece 532 and the moving contact piece 531 correspond to each other and contact. When the two are in contact, the annular light belt 52 is turned on. That is, under normal road conditions, the annular light belt 52 on the concave measuring unit 4 can be turned on and is in a lit state; as Figure 10 , when there is a local protrusion on the road surface, it will cause the outer moving shell 421 to move upward along with the detection wheel 44. At this time, the follower rod 42 is in a compressed state, which further separates the fixed contact piece 532 and the moving contact piece 531, also turning off the annular light belt 52. At the same time, the lower end part of the outer attachment layer 51 entering the outer moving shell 421 increases, squeezing some gas to the outer attachment layer 51 outside the outer moving shell 421, causing it to expand abnormally. Based on these three situations, the auxiliary camera 62 can also visually determine whether the road surface corresponding to the captured image is normal, whether there are protrusions or depressions.

[0052] It should be noted that in the natural state, the outer diameter of the outer attachment layer 51 is larger than the inner diameter of the outer moving shell 421, and the outer diameter of the middle part of the I-shaped rod 422 is smaller than the inner diameter of the outer moving shell 421. After the outer attachment layer 51 enters the outer moving shell 421, it will be squeezed, causing the outer attachment layer 51 outside to expand.

[0053] In summary, through the settings of the surface crack detection unit and the hidden crack detection unit, the identification of surface cracks and slight depressions can be achieved simultaneously. When the road surface is flat and there are no slight depressions, the bottoms of multiple concave measuring units 4 will be on a straight line. At this time, the data of the two laser rangefinders 801 tend to remain unchanged. When there are slight depressions, the bottom of the concave measuring unit 4 at the depression will be lower, causing the corresponding light display board 7 to move down. At this time, the data of one of the laser rangefinders 801 will decrease. At this time, the main camera 61 and the auxiliary camera 62 can be controlled to take pictures simultaneously, and the two picture-taking information can be combined into a set of data, thereby realizing the online marking of slight depressions. At the same time, toner can fall at the secondary marking tube 33 to mark the road surface, facilitating the staff to quickly lock the area where hidden cracks may occur during road maintenance, and thus facilitating the timely maintenance of this type of crack. Compared with the method of taking pictures to obtain road surface image information in the prior art, the probability of detecting hidden cracks is greatly increased, and thus the impact of hidden cracks on traffic and road life is effectively reduced.

[0054] Combined with the current actual needs, the above-mentioned implementation manner adopted in this application, the protection scope is not limited to this. Within the scope of knowledge possessed by those skilled in the art, various changes made without departing from the concept of this application still fall within the protection scope of the present invention.

Claims

1. A road and bridge pavement crack detection device, characterized in that: It includes a detection trolley (1). A top plate (21) is fixedly connected to the lower end of the detection trolley (1). L-shaped side plates (22) are fixedly connected to the left and right lower ends of the top plate (21). A marking unit is installed on the L-shaped side plates (22). The marking unit includes a double-chamber powder box (31) fixed to the upper end of the L-shaped side plate (22), a main marking tube (32) and a secondary marking tube (33) fixedly connected to the lower end of the double-chamber powder box (31). The main marking tube (32) and the secondary marking tube (33) are arranged side by side front and back, and both penetrate through the L-shaped side plate (22) and extend below the L-shaped side plate (22). The interior of the double-chamber powder box (31) is divided into two chambers, and different colored powders are filled in the two chambers respectively. A surface crack detection unit is arranged at the lower end of the top plate (21). The surface crack detection unit includes a main camera (61) fixedly connected to the lower end of the top plate (21) and a plurality of evenly distributed concave detection units (4). A hidden crack detection unit is jointly arranged between the plurality of concave detection units (4) and the two L-shaped side plates (22). The hidden crack detection unit includes two mounting plates (8) respectively fixedly connected to the lower ends of the two L-shaped side plates (22), a plurality of light-emitting plates (7) respectively fixedly connected to the outer ends of the plurality of concave detection units (4), and a secondary camera (62) fixedly connected to the top of the top plate (21). Laser rangefinders (801) are fixedly connected to one end of each of the two mounting plates (8) close to each other. The concave detection unit (4) includes a positioning rod (41) fixedly connected to the top plate (21), a follower rod (42) fixedly connected to the lower end of the positioning rod (41), a double-arm frame (43) fixedly connected to the lower end of the follower rod (42), and a detection wheel (44) rotatably connected between the two arms of the double-arm frame (43). The light-emitting plate (7) includes two connecting rods (71) fixedly connected to the double-arm frame (43), a frame (72) fixedly connected to the ends of the two connecting rods (71), and a light-transmitting sheet (73) fixedly embedded in the center of the frame (72). The upper and lower ends of the plurality of light-transmitting sheets (73) are semicircular. The two laser rangefinders (801) are arranged in a staggered manner. When the plurality of concave detection units (4) and the wheels of the detection trolley (1) are in contact with the horizontal ground synchronously, the laser beams emitted by the two laser rangefinders (801) respectively pass through the centers of the two semicircles on the light-transmitting sheet (73). A plurality of light guide bars (9) are fixedly embedded in the light-transmitting sheet (73). Both ends of the plurality of light guide bars (9) extend to the surface of the light-transmitting sheet (73), and the connection line between the midpoints of the ends of the plurality of light guide bars (9) coincides with the vertical center line of the light-transmitting sheet (73).

2. The crack detection device for a road and bridge pavement according to claim 1, characterized in that: The main camera (61) and the secondary camera (62) are arranged side by side, and both are located on the side of the plurality of concave detection units (4) away from the traveling direction of the detection trolley (1). The shooting end of the main camera (61) faces downward, and the shooting end of the secondary camera (62) faces the plurality of concave detection units (4).

3. The crack detection device for road and bridge pavement according to claim 1, characterized in that: When none of the concave measuring units (4) is under force, the lower end of the concave measuring unit (4) is lower than the lower end of the wheel hub of the detection trolley (1).

4. The road and bridge pavement crack detection device according to claim 1, characterized in that: The plurality of light guide bars (9) are all in a broken line structure and are made of a transparent light guide material. The parts of the plurality of light guide bars (9) located inside the light transmissive sheet (73) do not overlap with each other, and the two ends of the same light guide bar (9) are symmetric about the horizontal center line of the light transmissive sheet (73).

5. The road and bridge pavement crack detection device according to claim 1, characterized in that: The follower rod (42) includes an outer moving shell (421) fixedly connected to the double-arm frame (43), an I-shaped rod (422) fixedly connected to the positioning rod (41), and an elastic member (423) fixedly connected between the lower end of the I-shaped rod (422) and the inner bottom end of the outer moving shell (421). The lower end of the I-shaped rod (422) extends into the interior of the outer moving shell (421), and an indicating unit is connected between the outer moving shell (421) and the I-shaped rod (422).

6. The road and bridge pavement crack detection device according to claim 5, characterized in that: The indicating unit includes a circular light strip (52) installed at the outer end of the outer moving shell (421), a moving contact piece (531) and a fixed contact piece (532) electrically connected to the circular light strip (52), and an outer attachment layer (51) wrapped around the outer end of the middle part of the I-shaped rod (422). The moving contact piece (531) is fixedly inlaid at the outer end of the bottom of the I-shaped rod (422), the fixed contact piece (532) is fixedly inlaid on the inner wall of the mouth of the outer moving shell (421), the interior of the outer attachment layer (51) is filled with saturated air, and the lower end of the outer attachment layer (51) is located inside the outer moving shell (421). The outer attachment layer (51) is made of an elastic sealing material.

7. The road and bridge pavement crack detection device according to claim 6, characterized in that: When the concave measuring unit (4) is not under force, the moving contact piece (531) is located below the fixed contact piece (532); when the concave measuring unit (4) is flush with the bottom of the wheel hub of the detection trolley (1), the fixed contact piece (532) corresponds to and contacts the moving contact piece (531), and when the two contact, the circular light strip (52) is turned on.

Images