Vehicle-mounted asphalt pavement damage automatic detection equipment

Abstract

The invention relates to the technical field of road detection, and discloses vehicle-mounted asphalt pavement damage automatic detection equipment which comprises a rear vehicle body and a front vehicle body hinged to the front side of the rear vehicle body, and a camera shooting assembly for collecting pavement information is arranged on the upper side of the rear end of the rear vehicle body; a positioning pin for positioning the front vehicle body penetrates through the front end of the rear vehicle body; a plurality of parallel V-shaped folding frames are hinged to the lower side of the front vehicle body, and detection wheels are mounted at the lower ends of the V-shaped folding frames; a first tension spring for opening the V-shaped folding frame is mounted on the front vehicle body; an angle sensor for detecting the rotation angle of the V-shaped folding frame is mounted on the front vehicle body; after the angle sensor detects that the angle change exceeds a threshold value, the camera shooting assembly collects road surface information; when the detection wheel detects road surface damage, the camera shooting assembly collects road surface information, and the image processing data volume is reduced; the tension spring is matched with the V-shaped folding frame, so that the transverse stress of the detection wheel is reduced; and a turnover and folding double-vehicle-body structure is adopted, so that the use stability and the transfer convenience are achieved.

Description

Technical Field

[0001] This invention relates to the field of road inspection technology, specifically to a vehicle-mounted automatic asphalt pavement damage detection device. Background Technology

[0002] Asphalt pavement damage is a common defect during road use, mainly including cracking, deformation, surface damage, and other special types of damage. Among cracks, transverse cracks are often formed by temperature shrinkage, subgrade settlement, or reflection from base course cracking, and are perpendicular to the road centerline; longitudinal cracks often extend longitudinally along the road, caused by uneven subgrade compaction or foundation displacement; network cracks resemble tortoise shell patterns and are the result of material aging or fatigue damage. In terms of deformation, ruts are longitudinal grooves formed by repeated wheel rolling on the pavement, especially common in areas with heavy vehicle traffic, and are related to insufficient high-temperature stability of the material or weak base course strength; subsidence is localized pavement sinking, caused by insufficient subgrade compaction or foundation softening; bulges are localized pavement uplifts, caused by poor material gradation or improper construction and compaction. Among surface damage categories, potholes are craters in the road surface caused by water damage or material aging; pitting and exposed aggregate are characterized by the loss of fine aggregate or exposure of coarse aggregate, caused by insufficient asphalt content or freeze-thaw damage; loosening and peeling are caused by the loosening or detachment of surface material particles, resulting from poor adhesion between asphalt and aggregate. These damages not only affect driving comfort and safety but also accelerate road structure deterioration, requiring prevention and control through strict construction quality control and timely repairs.

[0003] Road surface damage detection is a crucial aspect of asphalt road maintenance, requiring a combination of manual inspection and technical methods to conduct multi-dimensional testing, from identifying surface defects to assessing structural performance. Methods for road surface damage detection include: Manual inspection: Observing the road surface on foot or by vehicle, recording the location and morphology of defects such as cracks, potholes, and ruts. Advantages include flexibility, intuitiveness, and the ability to identify minor damage; disadvantages include low efficiency, significant susceptibility to subjective human factors, and unsuitability for long-distance road sections. Vehicle-mounted detection wheel inspection: Examples include patents CN112554012B (a road surface damage measurement device and method) and CN219951628U (a road surface damage detection device). Existing detection wheel devices suffer from significant lateral forces when the wheel moves vertically and passes potholes, making them prone to damage. Size limitations also prevent the detection of cracks. Laser camera detection system inspection: Equipped in vehicles or drones, this method is highly efficient, utilizing image recognition technology (such as convolutional neural networks, CNNs) to process the captured data. With technological advancements, accuracy is continuously improving; disadvantages include continuous shooting and a large volume of image processing data. Summary of the Invention

[0004] The purpose of this invention is to solve at least one of the problems in the prior art mentioned above, and to provide a vehicle-mounted automatic asphalt pavement damage detection device.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A vehicle-mounted automatic asphalt pavement damage detection device includes a rear vehicle body and a front vehicle body hinged to the front of the rear vehicle body. A camera assembly for collecting pavement information is located on the upper rear end of the rear vehicle body. A positioning pin for positioning the front vehicle body is inserted through the front end of the rear vehicle body. Several parallel V-shaped folding frames are hinged to the lower side of the front vehicle body, and detection wheels are installed at the lower ends of the V-shaped folding frames. A first tension spring for opening the V-shaped folding frames is installed on the front vehicle body. An angle sensor for detecting the rotation angle of the V-shaped folding frames is installed on the front vehicle body. When the angle sensor detects an angle change exceeding a threshold, the camera assembly collects pavement information.

[0006] Furthermore, a flexible body is connected to the front side of the front vehicle body, and a towing ring connected to the power vehicle is connected to the front end of the flexible body.

[0007] Furthermore, a horizontally rotating platform is installed at the front end of the rear vehicle body, and the rear end of the front vehicle body is hinged to the upper side of the platform.

[0008] Furthermore, the rear vehicle body is equipped with a horizontally sliding rack and a gear meshing with the rack on the lower sides of both the front and rear ends. The lower sides of the four corners of the rear vehicle body are horizontally rotatably connected to wheel frames. One end of the wheel frame is equipped with a driving wheel, and the other end is hinged to the end of the rack via a connecting rod. The gears at both ends of the rear vehicle body are hinged to transmission rods, and the gear at the front end of the rear vehicle body rotates synchronously with the platform.

[0009] Furthermore, the V-shaped folding frame includes a support plate and a wheel plate, with the wheel plate being lower than the support plate; two parallel folding rods are hinged between the support plate and the front vehicle body, and between the support plate and the wheel plate, and the detection wheel is installed at the end of the wheel plate.

[0010] Furthermore, the front vehicle body is equipped with restraint ropes for binding the V-shaped folding frame.

[0011] Furthermore, an elastic rope is connected between the lower ends of the V-shaped folding frame, and a water spray pipe is provided at the lower end of the V-shaped folding frame to spray water onto the road surface in front of the detection wheel. A water supply assembly for supplying water to the water spray pipe is provided on the upper side of the middle of the rear vehicle body.

[0012] Furthermore, several radial detection rods are slidably passed through the side wall of the detection wheel; the inner end of the detection rod is connected to a first piston, and the side wall of the detection wheel is provided with a stepped hole for the detection rod and the first piston to slide; the inner ring side of the detection wheel is provided with an oil shell that communicates with the stepped hole and is filled with oil, and a pressure cylinder is connected to the inner ring side of the oil shell, and a sliding second piston is provided inside the pressure cylinder, and a second tension spring is connected to the inner side of the second piston.

[0013] Furthermore, the pressure cylinder is divided into a force-applying section and a measuring section with different diameters. The inner diameter of the force-applying section is larger than that of the measuring section, and the second piston slides within the measuring section. The force-applying section is connected to the oil tank. A fixed ring and a movable circular frame that slides along the inner side of the force-applying section are provided within the force-applying section. The second tension spring is connected between the movable circular frame and the fixed ring, and a traction rope is connected between the movable circular frame and the second piston.

[0014] Furthermore, the pressure cylinder is provided with a cylinder cover at its end, and a distance sensor for detecting the position of the second piston is provided inside the cylinder cover; after the distance sensor detects that the distance to the second piston is greater than a threshold, the camera component collects road surface information.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention employs a detection method that combines a detection wheel and a camera assembly. When the detection wheel detects road surface damage, the camera assembly collects road surface information, reducing the amount of image processing data. The detection wheel of the present invention is supported by a tension spring and a V-shaped folding frame, which enables the detection wheel to make stable contact with the road surface, and the deformation of the V-shaped folding frame reduces the lateral force on the detection wheel and its connecting structure, thereby reducing damage. This invention adopts a flip-foldable double-body structure. The rear body provides walking stability, while the front body makes the detection wheel structure more independent and stable. The V-shaped folding frame can also be folded, which can significantly reduce the overall volume after folding, thus combining stability in use and convenience in transportation. The rear body of this invention has a four-wheel synchronous steering structure, which improves the stability of the equipment and reduces turning friction. Through the horizontally rotatable front body, the equipment can automatically turn when towed behind a powered vehicle. This invention features a water spray structure, which, when activated, can remove foreign objects from the front side of the detection wheel, reduce color difference in image acquisition, and improve detection accuracy. This invention employs a detection wheel with an elastic detection rod, enabling the detection wheel to detect cracks. By controlling the hydraulic pressure and the position of the second piston, road surface crack information is obtained, and then road surface information is acquired through a camera component. This invention uses a two-stage pressure cylinder, with the second tension spring and the second piston positioned and linked separately. This ensures that the detection rod has sufficient rebound force and also expands the stroke of the second piston, thus guaranteeing the sensitivity and accuracy of crack detection. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the front-end three-dimensional structure of the present invention.

[0017] Figure 2 for Figure 1 Enlarged schematic diagram of part A in the middle.

[0018] Figure 3This is a schematic diagram of the three-dimensional structure of the rear end of the present invention.

[0019] Figure 4 This is a side view of the present invention.

[0020] Figure 5 This is a bottom view diagram of the present invention.

[0021] Figure 6 This is a rear view schematic diagram of the present invention.

[0022] Figure 7 This is a side view of the detection wheel of the present invention.

[0023] Figure 8 This is a schematic diagram of the working structure of the detection rod of the present invention.

[0024] Figure 9 This is a schematic diagram of the internal structure of the pressure cylinder of the present invention.

[0025] Figure 10 This is a schematic diagram of the semi-folded state of the present invention.

[0026] Figure 11 This is a schematic diagram of the fully folded state of the present invention.

[0027] Figure 12 for Figure 11 Enlarged schematic diagram of section B.

[0028] In the diagram: 1. Rear body; 2. Wheel; 3. Camera assembly; 4. Front body; 5. V-shaped folding frame; 6. Detection wheel; 7. Trailer ring; 8. Flexible body; 9. Platform; 10. Positioning pin; 11. Rack; 12. Wheel frame; 13. Linkage rod; 14. Gear; 15. Transmission rod; 16. Elastic rope; 17. Water spray pipe; 18. Water tank; 19. Water supply pipe; 20. Angle sensor; 21. Lever arm; 22. First tension spring; 23. Restraint rope; 24. Reflective strip; 25. Solid tire; 26. Detection rod; 27. Stepped hole; 28. First piston; 29. ​​Oil pan; 30. Force application section; 31. Measuring section; 32. Fixing ring; 33. Movable circular frame; 34. Second piston; 35. Second tension spring; 36. Traction rope; 37. Cylinder cover; 38. Distance sensor; 39. Water pump; 51. Support plate; 52. Wheel plate; 53. Folding rod. Detailed Implementation

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the present invention; that is, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0030] Specific embodiment 1 of the vehicle-mounted automatic asphalt pavement damage detection device provided by the present invention: Please see Figure 1-6 and Figure 10-12 The vehicle-mounted automatic asphalt pavement damage detection equipment adopts a dual-body structure and is towed to the rear of a power vehicle, moving with the power vehicle to detect pavement damage. It includes a rear body 1 and a front body 4 hinged to the front of the rear body 1. The dual-body structure provides better walking stability and reduces the impact of vertical movement of the power vehicle's suspension. The rear end of the front body 4 rotates vertically around the front end of the rear body 1, allowing the front body 4 to be flipped and folded and placed on the rear body 1. After the front body 4 is flipped and folded, the length of the equipment is significantly reduced, making it easy to transport directly using a power vehicle when not performing detection.

[0031] An inverted L-shaped plate is connected to the front side of the front vehicle body 4. A flexible body 8 is connected to the lower front side of the inverted L-shaped plate. A towing ring 7 connected to the power vehicle is connected to the front end of the flexible body 8. The inverted L-shaped plate makes the towing ring 7 close to the height of the power vehicle's tow hook. The flexible body 8 serves as a connecting component for transmitting power from the power vehicle to this device. Compared with a rigid connection structure, this device can both follow the movement of the power equipment and reduce the vertical movement of the power vehicle body to transmit power to this device. The flexible body 8 can be a chain. In some other embodiments, the flexible body 8 can be a flexible shaft, a wire rope, or a rubber belt reinforced with steel wire.

[0032] The rear vehicle body 1 has a horizontally sliding rack 11 and a gear 14 meshing with the rack 11 on the lower sides of both the front and rear ends. Specifically, the lower sides of the front and rear ends of the rear vehicle body 1 are provided with guide rails. The rack 11 slides horizontally along the guide rails. There are two gears 14, which are horizontally rotatably installed at the front and rear ends of the rear vehicle body 1 and mesh with the rack 11 at the front and rear ends of the rear vehicle body 1.

[0033] Wheel frames 12 are horizontally rotatably connected to the lower sides of the four corners of the rear vehicle body 1. The wheel frames 12 are bent plate-like structures, and the bent parts of the wheel frames 12 are horizontally rotatably connected to the rear vehicle body 1. A travel wheel 2 is rotatably mounted on the outer side of one end of the wheel frame 12, and the other end is hinged to the end of the rack 11 via a connecting rod 13. There are four travel wheels 2, four wheel frames 12, and four connecting rods 13. Each travel wheel 2 corresponds to one set of wheel frames 12 and connecting rods 13. Both ends of the rack 11 are hinged to connecting rods 13. When the gear 14 rotates, it causes the rack 11 to slide laterally. The laterally sliding rack 11 adjusts the angle of the travel wheels 2 at both ends through the wheel frames 12 and connecting rods 13, allowing the rear vehicle body 1 to turn smoothly and reducing the friction between the travel wheels 2 and the ground. In this embodiment, the outer ring of the travel wheel 2 has a solid rubber tire.

[0034] In order to achieve synchronous steering of the four wheels of the rear vehicle body 1, a transmission rod 15 is hinged between the gears 14 at both ends of the rear vehicle body 1. There are two transmission rods 15. When one gear 14 rotates and changes its angle, the other gear 14 is rotated and changed its angle synchronously through the transmission rod 15, so that the racks 11 at both ends of the rear vehicle body 1 move laterally in the same direction, thereby making the four wheels 2 turn synchronously.

[0035] A horizontally rotating platform 9 is installed at the front end of the rear vehicle body 1. The rear end of the front vehicle body 4 is hinged to the upper side of the platform 9. The gear 14 at the front end of the rear vehicle body 1 is connected to the platform 9 and rotates synchronously. When this device moves with the powered vehicle, when the powered vehicle turns at an intersection, it pulls the front vehicle body 4 to move, causing the front vehicle body 4 to rotate relative to the rear vehicle body 1. The front vehicle body 4 drives the gear 14 at the front end of the rear vehicle body 1 to rotate, causing the four wheels 2 of the rear vehicle body 1 to turn. During the turning process, this facilitates the smooth turning of the rear vehicle body 1, reduces the friction between the wheels 2 of the rear vehicle body 1 and the ground, and improves the stability of the rear vehicle body 1.

[0036] A positioning pin 10 is inserted through the front end of the rear vehicle body 1 to position the front vehicle body 4. The positioning pin 10 is set on the platform 9, and a support is provided on the upper side of the platform 9 to support the positioning pin 10. The positioning pin 10 is a cylindrical structure with a T-shaped cross-section. A helical spring is sleeved on the outside of the positioning pin 10, and the helical spring connects the support and the head of the positioning pin 10. The front vehicle body 4 has a positioning hole. When the front vehicle body 4 is in front of the rear vehicle body 1, the positioning pin 10 extends into the positioning hole of the front vehicle body 4, and the front vehicle body 4 cannot be flipped, ensuring stability during testing. By overcoming the elastic force of the helical spring, the positioning pin 10 can be pulled out from the positioning hole, and the front vehicle body 4 can be flipped to the upper side of the rear vehicle body 1 to achieve folding.

[0037] A gantry frame is provided on the upper rear side of the rear of the rear vehicle body 1, and a camera component 3 for collecting road information is provided on the upper side of the gantry frame. The camera component 3 includes several wide-angle cameras and infrared light sources, all facing the road surface behind the rear of the rear vehicle body 1, and can comprehensively collect image and video information of the road surface.

[0038] The preferred power vehicle is an MPV with the rear seats removed. In this embodiment, the width of both the front body 4 and the rear body 1 is smaller than the width of the inside of the power vehicle. When not in use, the device can be folded and placed inside the power vehicle for transport. During the movement of the device with the power vehicle, the smaller width of the device compared to the power vehicle reduces the impact on the rear vehicle driver's view of the power vehicle's taillights.

[0039] Rear reflective strips 24 are affixed to both the gantry frame and the rear side of the rear vehicle body 1. This facilitates visibility of the equipment for drivers of following vehicles in low-light conditions, improving safety during operation. Road inspection signs are affixed to the upper rear side of the powered vehicle to alert drivers of following vehicles, further enhancing safety.

[0040] Several parallel V-shaped folding frames 5 are hinged to the lower side of the front vehicle body 4. In this embodiment, there are two V-shaped folding frames 5. In other embodiments, multiple frames can be set to improve the comprehensiveness of the inspection. Inspection wheels 6 are installed at the lower end of the V-shaped folding frames 5.

[0041] The V-shaped folding frame 5 includes a support plate 51 and a wheel plate 52. The wheel plate 52 is lower than the support plate 51. The V-shaped opening of the V-shaped folding frame 5 faces forward, i.e. towards the powered vehicle, and its structure is similar to the support of the pantograph. When the V-shaped folding frame 5 is unfolded, the height of the support plate 51 is between the wheel plate 52 and the front of the front body 4.

[0042] In this embodiment, the front vehicle body 4 has a Z-shaped frame structure. In the detection state, i.e., when the front vehicle body 4 is located in front of the rear vehicle body 1, the front vehicle body 4 includes two horizontal sections and a vertical section connecting the two horizontal sections. The horizontal section at the front end of the front vehicle body 4 is higher than the horizontal section at the rear end, and the front-to-back span of the horizontal section at the front end is greater than the front-to-back span of the horizontal section at the rear end. The V-shaped folding frame 5 is located below the horizontal section at the front end of the front vehicle body 4.

[0043] Two parallel folding rods 53 are hinged between the support plate 51 and the front vehicle body 4, and between the support plate 51 and the wheel plate 52, forming an upper and lower double parallelogram structure, so that the support plate 51 and the wheel plate 52 are always horizontal, and the detection wheel 6 is installed at the end of the wheel plate 52.

[0044] In this embodiment, each V-shaped folding frame 5 includes four folding rods 53, with two folding rods 53 on each side of the support plate 51. The two parallel folding rods 53 on the lower side of the support plate 51 are located on different horizontal sides of the support plate 51, and the two parallel folding rods 53 on the upper side of the support plate 51 are located on different horizontal sides of the support plate 51. The staggered structure of the folding rods 53 makes the folding rods 53 closer to the horizontal after the V-shaped folding frame 5 is fully folded, reducing the longitudinal span after folding and making the volume smaller after folding. On the other hand, the folded V-shaped folding frame 5 is flipped and folded with the front vehicle body 4, and can be placed more compactly on the upper side of the rear vehicle body 1.

[0045] To automatically unfold the V-shaped folding frame 5 and thus allow the detection wheel 6 to adhere to the ground, a first tension spring 22 is installed on the front body 4 to open the V-shaped folding frame 5. Specifically, a folding rod 53 on the upper side of the support plate 51 is connected to a lever 21 at its upper end. The end of the lever 21 is connected to the aforementioned first tension spring 22 between it and the middle of the horizontal part at the front end of the front body 4. There are two first tension springs 22, and each of the two springs unfolds one V-shaped folding frame 5.

[0046] The front vehicle body 4 is equipped with a restraint rope 23 for binding the V-shaped folding frame 5. The V-shaped folding frame 5 is folded by overcoming the tension of the first tension spring 22, and then the folding rod 53 is secured to the front vehicle body 4 by the restraint rope 23, preventing the V-shaped folding frame 5 from unfolding. In some embodiments, a rope buckle can be used to prevent the restraint rope 23 from loosening. In some embodiments, multiple restraint ropes 23 are provided. After the front vehicle body 4 is flipped and folded onto the upper side of the rear vehicle body 1, the restraint ropes 23 are used to bind the front vehicle body 4 and the rear vehicle body 1 together, improving the stability of the front vehicle body 4 on the upper side of the rear vehicle body 1 and further preventing the V-shaped folding frame 5 from unfolding.

[0047] An angle sensor 20 is installed on the front body 4 to detect the rotation angle of the V-shaped folding frame 5. Specifically, the upper end of one folding rod 53 on the upper side of the support plate 51 is connected to a lever arm 21, and the upper hinge of the other folding rod 53 on the upper side of the support plate 51 is detected by the angle sensor 20 to detect the rotation angle. The angle sensor 20 detects the rotation angle of the V-shaped folding frame 5 by detecting the angle change at the upper end of the folding rod 53.

[0048] The detection wheel 6 moves on a smooth road surface, with the V-shaped folding frame 5 at a constant angle. When the detection wheel 6 passes over deformed areas, grooves, or bumps in the road surface, it adheres to the ground, causing the rotation angle of the V-shaped folding frame 5 to change. When the angle change reaches a threshold, it indicates road damage. Once the angle sensor 20 detects that the angle change exceeds the threshold, the camera assembly 3 immediately starts collecting road information for a certain period, such as capturing ten seconds of video or taking multiple photos within ten seconds. In this way, it is unnecessary to collect massive amounts of image information on roads stretching tens of kilometers; only targeted images of suspected damaged areas need to be collected for further image analysis, significantly reducing the workload of image processing.

[0049] An elastic rope 16 is connected between the lower ends of the V-shaped folding frame 5. In this embodiment, there is one elastic rope 16, which is connected between the wheel plates 52 of the two V-shaped folding frames 5. On a flat road surface, the elastic rope 16 does not apply lateral force to the wheel plates 52. When the detection wheel 6 at the lower end of one V-shaped folding frame 5 is subjected to vertical displacement due to road surface deformation, the elastic rope 16 tilts and lengthens, providing an auxiliary restoring force to the detection wheel 6.

[0050] The lower end of the V-shaped folding frame 5 is equipped with a water spray pipe 17 for spraying water onto the road surface in front of the detection wheel 6. The water spray pipe 17 is inclined and has several nozzles that spray high-pressure water towards the road surface in front of the detection wheel 6. This can remove impurities and foreign objects from the road surface, preventing them from affecting the detection wheel 6, and can also clean the road surface. It also helps to reduce color difference in the image acquisition of the subsequent camera component 3, thereby improving the accuracy of the detection. There are two water spray pipes 17, which are connected by a flexible hose. The flexible hose connecting the two water spray pipes 17 does not affect the independent vertical movement of the two detection wheels 6, and also serves to connect the water spray pipes 17.

[0051] A water supply assembly for supplying water to the water spray pipe 17 is located on the upper side of the middle of the rear vehicle body 1. The water supply assembly includes a water tank 18 and a water pump 39 located on the upper side of the rear vehicle body 1. The water pump 39 draws water from the water tank 18, and a water supply pipe 19 is connected between the output end of the water pump 39 and the water spray pipe 17. The water supply pipe 19 is a flexible hose that can accommodate the flipping and folding of the front vehicle body 4. The water tank 18 can act as a counterweight on the rear vehicle body 1 to stabilize its movement. The water pump 39 supplies water from the water tank 18 to a water spray pipe 17 under high pressure through the water supply pipe 19. The high-pressure water is sprayed out through the nozzle and washes the road surface at an angle forward. When the front vehicle body 4 is flipped and folded on top of the rear vehicle body 1, the water tank 18 passes through the frame-like front vehicle body 4.

[0052] Specific embodiment 2 of the vehicle-mounted automatic asphalt pavement damage detection device provided by the present invention: Although the detection wheel 6 can detect the undulations of the asphalt pavement, its size limits its ability to smoothly pass over crack surfaces, preventing the detection of pre-existing cracks and causing some missed detections. Therefore, in this embodiment, several radial detection rods 26 are slidably inserted through the sidewall of the detection wheel 6. The inner end of the detection rod 26 is connected to a first piston 28. The sidewall of the detection wheel 6 is provided with stepped holes 27 for the detection rods 26 and the first piston 28 to slide. The inner ring side of the detection wheel 6 is provided with an oil shell 29 that communicates with the stepped holes 27 and is filled with oil. The oil shell 29 is annular with a U-shaped cross-section and covers the inner ring side of the detection wheel 6. An oil storage cavity is formed between the oil shell 29 and the inner ring side of the detection wheel 6. A pressure cylinder is connected to the inner ring side of the oil shell 29. A sliding second piston 34 is provided inside the pressure cylinder. A second tension spring 35 is connected to the inner side of the second piston 34.

[0053] In this embodiment, the outer side of the detection wheel 6 is provided with a solid rubber tire 25, and the solid tire 25 is provided with several through holes corresponding to the stepped holes 27, through which the detection rod 26 slides.

[0054] The stepped hole 27 is a through hole on the side wall of the detection wheel 6. The first piston 28 slides along the inner side of the large section of the stepped hole 27, and the detection rod 26 slides through the small section of the stepped hole 27 and the through hole on the solid tire 25. The detection rod 26 protrudes from the outer side of the solid tire 25 and can extend into the crack when it encounters a crack.

[0055] The second tension spring 35 presses the oil in the oil casing 29 inward from the inside of the second piston 34, generating hydraulic pressure. This hydraulic pressure is transmitted to the first piston 28, causing all the detection rods 26 to extend out of the solid tire 25.

[0056] The force exerted by the second tension spring 35 on the detection rod 26 is less than the force exerted by the first tension spring 22 on the detection wheel 6. When the first tension spring 22 makes the detection wheel 6 adhere to the ground, it also causes several detection rods 26 on the lower side of the detection wheel 6 to retract. These detection rods 26 are pressurized by the first piston 28 at their inner end, causing the second piston 34 to overcome the tension of the second tension spring 35 and move to the outer end of the pressure cylinder.

[0057] During the road surface smoothing inspection, as the inspection wheel 6 rolls, some of the inspection rods 26 are constantly in contact with the road surface and pressed back, causing the second piston 34 to fluctuate within a small range. When cracks exist in the road surface, the ends of several inspection rods 26 on the underside of the inspection wheel 6 extend into the cracks, causing a decrease in the total oil pressure of the first piston 28. The second tension spring 35 causes the second piston 34 to move inward and away from the end of the pressure cylinder, resulting in a significant displacement difference between the second piston 34 and the smooth road surface.

[0058] The pressure cylinder has a cap 37 at its end, which is connected to the end of the pressure cylinder by threads. Inside the cap 37 is a distance sensor 38 for detecting the position of the second piston 34, preferably a sensor that transmits data wirelessly. Based on the fact that the second piston 34 will change position after the detection wheel 6 passes through the crack, the camera assembly 3 collects road surface information after the distance sensor 38 detects that the distance to the second piston 34 is greater than a threshold. In some embodiments, a controller is provided. After receiving valid signals from the angle sensor 20 and the distance sensor 38, the controller controls the camera assembly 3 to immediately start collecting image information for a period of time.

[0059] The cylinder cover 37 has a vent hole, and when the second piston 34 moves inside the pressure cylinder, it balances the air pressure inside the pressure cylinder outside the second piston 34.

[0060] Specific embodiment 3 of the vehicle-mounted automatic asphalt pavement damage detection device provided by the present invention: When the detection wheel 6 has too few detection rods 26, if the detection rods 26 cannot correspond to the cracks, missed detections will occur. Furthermore, when the detection wheel 6 moves on a smooth road surface, the varying degrees of difference in the condition of the detection rods 26 being pressed back, along with the large fluctuation range in the position of the second piston 34, will affect the detection of cracks. Setting more detection rods 26 can improve the comprehensiveness of the detection, reduce missed detections, and also minimize the fluctuation range of the second piston 34's position when the detection wheel 6 moves on a smooth road surface.

[0061] During the experiment, a pressure cylinder with a uniform inner diameter was used. When the inner diameter of the pressure cylinder was small, the position of the second piston 34 changed significantly when encountering a crack. The distance sensor 38 could successfully and effectively detect the significant change in the position of the second piston 34 each time, thus detecting the presence of the crack. However, because the second tension spring 35 requires all detection rods 26 to extend from the detection wheel 6, the pressure cylinder with a small inner diameter could not hold a sufficient tension spring. When a pressure cylinder with a larger inner diameter was used, although the tension of the second tension spring 35 was sufficient, the change in the position of the second piston 34 was small when the detection wheel 6 passed through the crack, making it difficult to effectively distinguish the threshold. In addition, the position of the second piston 34 would also fluctuate when the detection wheel 6 was on a flat road surface, so the distance sensor 38 frequently experienced false detections and missed detections.

[0062] To overcome the above problems, please refer to Figure 7 , Figure 8 and Figure 9 In this embodiment, the pressure cylinder is divided into a force-applying section 30 and a measuring section 31 with different diameters. Both the force-applying section 30 and the measuring section 31 are circular tube sections. The inner diameter of the force-applying section 30 is larger than the inner diameter of the measuring section 31. The second piston 34 slides in the measuring section 31. The force-applying section 30 is connected to the oil shell 29. The force-applying section 30 is provided with a fixed ring 32 and a movable circular frame 33 that slides along the inner side of the force-applying section 30. The fixed ring 32 is closer to the oil shell 29. A second tension spring 35 is connected between the movable circular frame 33 and the fixed ring 32. A traction rope 36 is connected between the movable circular frame 33 and the second piston 34.

[0063] The larger inner diameter force application section 30 can accommodate a second tension spring 35 with a larger load capacity to provide greater tension, allowing the detection rod 26 to extend from the detection wheel 6 when no external force is applied. The smaller inner diameter measurement section 31 houses a smaller second piston 34, making its positional changes more noticeable and completely eliminating interference from the normal fluctuations of the second piston 34. The distance sensor 38, located at the end of the measurement section 31, can accurately detect the positional change of the second piston 34 when passing over a crack, accurately determining the presence of road surface cracks and ensuring accuracy.

[0064] In this embodiment, the measuring section 31 is further divided into an integrally connected curved tube section and a straight tube section, with the second piston 34 sliding within the straight tube section. The curved tube section is connected to the force application section 30, allowing the measuring section 31 to avoid the center position of the side of the detection wheel 6. The traction rope 36 passes through the curved tube section, without affecting the force transmission between the movable circular frame 33 and the second piston 34.

[0065] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still make modifications to the technical solutions described in the foregoing embodiments without creative effort, or make equivalent substitutions for some of the technical features. 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 vehicle-mounted automatic asphalt pavement damage detection device, characterized in that, The vehicle includes a rear body (1) and a front body (4) hinged to the front of the rear body (1). The rear body (1) is equipped with a camera assembly (3) for collecting road information on its upper rear end. The front end of the rear body (1) is provided with a positioning pin (10) for positioning the front body (4). The front body (4) is hinged with several parallel V-shaped folding frames (5). The lower end of the V-shaped folding frames (5) is equipped with a detection wheel (6). The front body (4) is equipped with a first tension spring (22) for opening the V-shaped folding frames (5). The front body (4) is equipped with an angle sensor (20) for detecting the rotation angle of the V-shaped folding frames (5). After the angle sensor (20) detects that the angle change exceeds the threshold, the camera assembly (3) collects road information.

2. The vehicle-mounted automatic asphalt pavement damage detection equipment according to claim 1, characterized in that, The front of the front vehicle body (4) is connected to a flexible body (8), and the front end of the flexible body (8) is connected to a towing ring (7) that is connected to the power vehicle.

3. The vehicle-mounted automatic asphalt pavement damage detection equipment according to claim 1, characterized in that, The rear vehicle body (1) is equipped with a horizontally rotating platform (9) at its front end, and the rear end of the front vehicle body (4) is hinged to the upper side of the platform (9).

4. The vehicle-mounted automatic asphalt pavement damage detection equipment according to claim 3, characterized in that, The rear vehicle body (1) is equipped with a horizontally sliding rack (11) and a gear (14) meshing with the rack (11) on the lower side of the front and rear ends. The lower side of the four corners of the rear vehicle body (1) is horizontally rotatably connected with a wheel frame (12). One end of the wheel frame (12) is equipped with a walking wheel (2), and the other end is hinged to the end of the rack (11) through a connecting rod (13). The gears (14) at both ends of the rear vehicle body (1) are hinged with a transmission rod (15). The gear (14) at the front end of the rear vehicle body (1) rotates synchronously with the platform (9).

5. The vehicle-mounted automatic asphalt pavement damage detection device according to claim 1, characterized in that, The V-shaped folding frame (5) includes a support plate (51) and a wheel plate (52), with the wheel plate (52) being lower than the support plate (51). Two parallel folding rods (53) are hinged between the support plate (51) and the front vehicle body (4) and between the support plate (51) and the wheel plate (52). The detection wheel (6) is installed at the end of the wheel plate (52).

6. The vehicle-mounted automatic asphalt pavement damage detection device according to claim 5, characterized in that, The front vehicle body (4) is provided with a restraint rope (23) for binding the V-shaped folding frame (5).

7. The vehicle-mounted automatic asphalt pavement damage detection device according to claim 1, 5, or 6, characterized in that, The lower ends of the V-shaped folding frame (5) are connected by elastic ropes (16), and the lower end of the V-shaped folding frame (5) is provided with a water spray pipe (17) for spraying water onto the road surface in front of the detection wheel (6). The upper side of the middle part of the rear vehicle body (1) is provided with a water supply assembly for supplying water to the water spray pipe (17).

8. The vehicle-mounted automatic asphalt pavement damage detection device according to claim 1, characterized in that, Several radial detection rods (26) are slidably passed through the side wall of the detection wheel (6); the inner end of the detection rod (26) is connected to a first piston (28); the side wall of the detection wheel (6) is provided with a stepped hole (27) for the detection rod (26) and the first piston (28) to slide; the inner ring side of the detection wheel (6) is provided with an oil shell (29) that communicates with the stepped hole (27) and is filled with oil; the inner ring side of the oil shell (29) is connected to a pressure cylinder; the pressure cylinder is provided with a sliding second piston (34); the inner side of the second piston (34) is connected to a second tension spring (35).

9. The vehicle-mounted automatic asphalt pavement damage detection device according to claim 8, characterized in that, The pressure cylinder is divided into a force-applying section (30) and a measuring section (31) with different diameters. The inner diameter of the force-applying section (30) is larger than that of the measuring section (31). The second piston (34) slides in the measuring section (31). The force-applying section (30) is connected to the oil shell (29). The force-applying section (30) is provided with a fixed ring (32) and a movable circular frame (33) that slides along the inner side of the force-applying section (30). The movable circular frame (33) is connected to the fixed ring (32) with a second tension spring (35). The movable circular frame (33) is connected to the second piston (34) with a traction rope (36).

10. The vehicle-mounted automatic asphalt pavement damage detection device according to claim 8 or 9, characterized in that, The pressure cylinder is provided with a cylinder cover (37) at the end, and a distance sensor (38) for detecting the position of the second piston (34) is provided inside the cylinder cover (37); after the distance sensor (38) detects that the distance to the second piston (34) is greater than a threshold, the camera component (3) collects road surface information.

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