A device and method for detecting the thickness of a water film on a road surface

Abstract

This invention discloses a road surface water film thickness detection device, comprising: an outer cover with an opening at the bottom, allowing water to flow freely through; a water film thickness detection structure housed within the outer cover, the water film thickness detection structure being a water-sensitive color-changing coating applied to a supporting structure; the water film thickness value being the length of the color change of the water-sensitive color-changing coating upon contact with road surface water after the bottom end of the supporting structure contacts the road surface; and a road surface texture image acquisition device, which acquires a three-dimensional cloud image of the road surface texture of the measured area and transmits it to a data processing module. The data processing module identifies the road surface texture depth value of the measured area based on the three-dimensional cloud image, and then subtracts this depth value from the length of the color change of the water-sensitive color-changing coating to obtain the actual water film thickness value. The device is portable, allows for immediate use and measurement, reduces computational complexity, and provides accurate water film thickness measurements.

Description

Technical Field

[0001] This invention belongs to the field of highway surface water film thickness detection technology, and relates to a highway surface water film thickness detection device and method. Background Technology

[0002] The rapid increase in traffic volume has led to increasing congestion on many roads built earlier. To address this congestion, more and more extra-wide roads are appearing. Extra-wide roads are prone to water accumulation, forming a water film of a certain thickness. The presence of this water film weakens the friction coefficient between the tire tread and the road surface. Under the influence of fluid, the contact area between the tire and the road surface is significantly reduced, resulting in decreased vehicle stability. A survey conducted by the Ministry of Transport, "Research on Anti-skid Technology Standards for Highways," indicates that increased water film thickness leads to decreased road surface friction, resulting in a 6-8 times higher accident rate in rainy weather compared to sunny weather.

[0003] During rainfall, water accumulation on the road surface makes it slippery, reducing the frictional resistance between the road surface and tires. When a car drives over a flooded road, the water isolates the road surface from the tire, causing the tire to partially detach from the road surface, reducing the adhesion between them. Simultaneously, the dynamic lubrication effect of the water causes the tire to slip a certain distance, resulting in hydroplaning. At a certain speed, when a tire travels at high speed on a flooded road, the rotation of the tire displaces the water. The compression between the tire and the fluid generates dynamic water pressure. When the water film on the road surface reaches a certain thickness, the dynamic water pressure just lifts the tire completely off the road surface. This water film thickness is the critical water film thickness at that speed. Therefore, accurately obtaining the road surface water film thickness under rainfall conditions during highway operation is crucial for driving safety. Existing methods for measuring pavement water film mainly include contact and non-contact detection methods. Most contact detection methods require embedded detection elements, fixed measurement points, poor anti-interference performance, small measurement range, and high maintenance difficulty. They are suitable for roads where water film thickness data needs to be collected over a long period. However, most existing non-contact testing methods use instruments with complex structures, and the confidentiality of the technology makes them difficult to promote. The purchase of equipment is relatively expensive, and the requirements for the testing site environment are high. Summary of the Invention

[0004] The purpose of this invention is to provide a device and method for detecting the thickness of road surface water film, so as to solve the problems of existing contact detection methods that require embedded detection elements, fixed measuring points, poor anti-interference performance, small measurement range, and high maintenance difficulty, as well as the problems of existing non-contact detection methods that use instruments with complex structures, are difficult to promote, have high costs, and have high requirements for the detection site environment.

[0005] The technical solution adopted in this embodiment of the invention is: a highway surface water film thickness detection device, comprising:

[0006] The outer cover has an opening at the bottom, allowing water to flow smoothly through it.

[0007] The water film thickness detection structure is located inside the outer cover and is a water-sensitive color-changing coating applied to the support structure.

[0008] The length of the color change of the water-sensitive coating after the bottom of the support structure comes into contact with the road surface is the water film thickness value.

[0009] Furthermore, a moving mechanism is installed inside the outer cover, and the water film thickness detection structure is installed at the moving end of the moving mechanism;

[0010] The moving mechanism can drive the water film thickness detection structure to move vertically up and down inside the outer cover. The moving mechanism can be used to move the water film thickness detection structure until its bottom end contacts the road surface.

[0011] Furthermore, the water film thickness detection structure is mounted on a robotic arm, and the vertical movement of the water film thickness detection structure is caused by the raising and lowering of the robotic arm.

[0012] Furthermore, the water film thickness detection structure is provided in multiple ways;

[0013] Multiple of the aforementioned water film thickness detection structures are vertically mounted on a single arm of a multi-arm robotic arm.

[0014] Furthermore, the water film thickness detection structure employs multiple probes coated with a water-sensitive color-changing coating;

[0015] Multiple probes can be detachably and vertically mounted on a single arm of a multi-arm robotic arm, with all probes staggered.

[0016] Each arm of the multi-arm robotic arm is rotatably connected to its corresponding connecting rod via a rotating shaft;

[0017] The connecting rods are divided into two groups. The group of connecting rods on the left side is fixedly connected to the first rotating component, and the group of connecting rods on the right side is fixedly connected to the second rotating component. When the first rotating component and the second rotating component rotate, they drive the connecting rods and the single arm to rotate horizontally inside the outer cover.

[0018] The outer cover is equipped with a movable guide rail. The first rotating component and the second rotating component are mounted on the movable guide rail via a connecting plate. The connecting plate can move up and down along the movable guide rail, driving the multi-arm robotic arm and probe to move vertically up and down inside the outer cover.

[0019] Furthermore, each arm of the multi-arm robotic arm is evenly provided with multiple mounting holes with snap-fit ​​fasteners;

[0020] The probe is vertically and detachably installed in the mounting hole via a snap fastener.

[0021] Furthermore, the aforementioned highway surface water film thickness detection device also includes:

[0022] A road surface texture image acquisition device acquires a three-dimensional cloud map of the road surface texture of the measured area and transmits it to a data processing module. The data processing module identifies the road surface texture depth value of the measured area based on the three-dimensional cloud map of the road surface texture, and then subtracts the road surface texture depth value from the color change length of the water-sensitive coating to obtain the actual water film thickness value.

[0023] Furthermore, the aforementioned highway surface water film thickness detection device also includes:

[0024] The camera system is used to capture images of the water film thickness detection structure and transmit them to the data processing module. The data processing module identifies the length of the color change of the water-sensitive coating on the water film thickness detection structure based on the images of the water film thickness detection structure.

[0025] A power supply module that provides operating voltage to electrical components;

[0026] The outer cover is a transparent cube structure with an open bottom, and its four corners are provided with support legs;

[0027] The outer casing has two partitions, which are arranged corresponding to two opposite side panels near the outer casing. Each partition and the side panel near it form a sealed cavity at the bottom, and the camera system and power supply module are placed in the cavity.

[0028] Another technical solution adopted in this embodiment of the invention is: a method for detecting the thickness of a road surface water film, which uses a road surface water film thickness detection device as described above, and includes the following steps:

[0029] Step S1: Apply the water-sensitive color-changing coating evenly to the probe, which serves as the support structure for measuring water film thickness, to form a water-sensitive color-changing coating.

[0030] Step S2: Under rainfall conditions, place the road surface water film thickness detection device in an area where the road surface water film is thicker and mark the center of that area;

[0031] Step S3: Manipulate the multi-arm robotic arm to spread the probes out into a square distribution. The diagonal length of the square where the probes are distributed is less than the side length of the scanning area of ​​the road texture image acquisition device. Manipulate the multi-arm robotic arm to descend, and the probe tip inserts into the ground. The water-sensitive color-changing coating of the probe changes color when it encounters the water film on the ground. Then, manipulate the multi-arm robotic arm to drive the probe up to the camera system. The camera system captures the image of the probe and transmits it to the data processing module. The data processing module analyzes and processes the image captured by the camera system and determines the length of the color change of the water-sensitive color-changing coating of the probe based on image recognition.

[0032] Step S4: The data processing module establishes a coordinate system XYZ with the ground point where any probe is located as the origin. The XY plane is parallel to the road surface and the Z axis is perpendicular to the road surface. The coordinate values ​​of each probe's measuring point are obtained. The Z value of each measuring point is the length of the color change of the water-sensitive coating of the corresponding probe.

[0033] Step S5: After the road surface dries, place the road surface water film thickness detection device back in the area to be measured according to the position of the marked point. Operate the multi-arm robotic arm to retract the probe to the side plate of the outer cover, and start the road surface texture image acquisition device to acquire the ground surface texture, obtain the three-dimensional cloud map of the road surface texture, and transmit it to the data processing module.

[0034] Step S6: The data processing module processes the 3D cloud map of the road surface texture and captures the origin of the XYZ coordinate system established in step S4. Based on the origin and the coordinate values ​​of each measuring point, the range of the measured area is extracted. Within the range of the measured area, a coordinate system XYZ based on the road surface texture depth is established using the origin of the XYZ coordinate system. ’ Z-coordinates of each measuring point ’ The value is the surface texture depth value at that measuring point;

[0035] Step S7: The data processing module obtains the water film thickness value Z at each measuring point based on the following formula. ’’ :

[0036] Z ’’ = ZZ ’ ;

[0037] Where Z is the length of the color change of the water-sensitive coating on the probe at each measuring point, Z ’ The surface texture depth value at each measuring point;

[0038] Step S8: Take the water film thickness value Z at each measuring point. ’’ The average value is used as the current road surface water film thickness detection value.

[0039] Furthermore, to eliminate the influence of capillary action in water-sensitive paints on the measurement of water film thickness, a calibration test needs to be conducted beforehand.

[0040] Use a graduated cylinder to measure water to a certain depth, insert a probe coated with a water-sensitive color-changing coating into the water, then take it out and measure its length with a vernier caliper. Compare the measured length with the initially determined water depth to obtain the difference.

[0041] Multiple sets of the above tests were conducted, and the average value of the differences obtained from the multiple sets of tests was taken. The average value of the differences was then used to calibrate the test results of the water film thickness.

[0042] The beneficial effects of the embodiments of the present invention are:

[0043] 1. The measurement is performed using a support structure coated with a water-sensitive color-changing coating. The thickness of the water film on the road surface can be obtained simply by reading the length of the color change of the water-sensitive color-changing coating on the support structure at the bottom that contacts the ground. This method is quick, convenient, low-cost, does not cause permanent damage to the road surface, and does not result in large deviations in measurement results due to excessively fast runoff velocity or a large amount of impurities in rainwater. Furthermore, the device is portable and can be used immediately. It can measure the thickness of the water film at any location on the road surface. This method solves the problems of existing contact detection methods, such as the need to embed detection elements, fixed measurement points, poor anti-interference performance, small measurement range, and high maintenance difficulty. It also solves the problems of existing non-contact detection methods, such as complex instrument structures, difficulty in promotion, high cost, and high requirements for the detection site environment.

[0044] 2. When paired with a road surface texture image acquisition device, the depth of the road surface texture can be fully considered during measurement. Based on the measured length of the color change of the water-sensitive coating and the depth of the road surface texture, a more accurate water film thickness value can be obtained, which greatly reduces the complexity of calculation and results in a more accurate measurement of the final water film thickness value.

[0045] 3. The design of the outer cover allows for the measurement of the water film thickness on the pavement within the cover area. The gap at the bottom of the cover does not obstruct water flow, and the cover design makes the detection device less susceptible to environmental influences, ensuring accurate measurement of the water film thickness. Attached Figure Description

[0046] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0047] Figure 1 This is a three-dimensional structural schematic diagram of a highway surface water film thickness detection device according to an embodiment of the present invention.

[0048] Figure 2 This is a schematic diagram of a road surface water film thickness detection device scanning road surface texture according to an embodiment of the present invention.

[0049] Figure 3 This is a front view schematic diagram of a highway surface water film thickness detection device according to an embodiment of the present invention.

[0050] Figure 4 This is a top view schematic diagram of a road surface water film thickness detection device according to an embodiment of the present invention.

[0051] Figure 5 This is a left-side view schematic diagram of a road surface water film thickness detection device according to an embodiment of the present invention.

[0052] Figure 6 This is a top view of the multi-arm robotic arm.

[0053] Figure 7 This is a top view diagram showing the connection between the connecting rod and the moving guide rail of a multi-arm robotic arm.

[0054] In the figure, 1. outer cover, 2. robotic arm, 3. water film thickness detection structure, 4. camera system, 5. partition, 6. road surface texture image acquisition device, 7. power supply module, 8. connecting plate, 9. connecting rod, 10. mounting hole, 11. single arm, 12. rotating shaft. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] Example 1

[0057] This embodiment proposes a device for detecting the thickness of road surface water film, such as... Figures 1-5 As shown, it includes:

[0058] Outer cover 1, with an opening at the bottom, allowing water to flow smoothly through;

[0059] Water film thickness detection structure 3 is set inside the outer cover 1. Water film thickness detection structure 3 is a water-sensitive color-changing coating applied to the support structure.

[0060] The length of the color change of the water-sensitive coating after the bottom of the support structure comes into contact with the road surface is the water film thickness value.

[0061] When the device is in use, the outer cover 1 serves to waterproof and windproof the internal electronic components, protecting them from damage. It also protects the probe from raindrops and splashes from the ground, preventing premature discoloration of the water-sensitive coating and thus affecting the measurement of the water film thickness. The water-sensitive coating is originally white, turning red upon contact with water.

[0062] In some embodiments, a moving mechanism is installed inside the outer cover 1, and the water film thickness detection structure 3 is installed at the moving end of the moving mechanism;

[0063] The moving mechanism can drive the water film thickness detection structure 3 to move vertically up and down inside the outer cover 1;

[0064] When performing water film thickness detection, the water film thickness detection structure 3 is moved to contact the road surface at its bottom by the moving mechanism; after the water film thickness detection is completed, the water film thickness detection structure 3 is moved upward to outside the water flow range by the moving mechanism.

[0065] In some embodiments, the water film thickness detection structure 3 is mounted on the robotic arm 2, and the water film thickness detection structure 3 moves vertically up and down by the raising and lowering of the robotic arm 2.

[0066] In some embodiments, the water film thickness detection structure 3 is provided in multiple ways;

[0067] The robotic arm 2 is a multi-arm robotic arm;

[0068] Multiple water film thickness detection structures 3 are vertically mounted on the single arm 11 of the multi-arm robotic arm, thereby improving detection accuracy.

[0069] In some embodiments, the water film thickness detection structure 3 employs multiple probes coated with a water-sensitive color-changing coating;

[0070] Multiple probes are detachably and vertically mounted on the single arm 11 of the multi-arm robotic arm;

[0071] The probe offers minimal resistance to water flow, avoiding the problem of inflated water film thickness readings caused by increased resistance from the supporting structure.

[0072] In some embodiments, the probe is a cylindrical structure that is thicker at the top and thinner at the bottom.

[0073] In some embodiments, the highway surface water film thickness detection device further includes:

[0074] The road surface texture image acquisition device 6 acquires a three-dimensional cloud image of the road surface texture in the measured area and transmits it to the data processing module. The data processing module identifies the road surface texture depth value based on the three-dimensional cloud image and then subtracts this depth value from the color change length of the water-sensitive coating on the probe to obtain the actual water film thickness value. This solves the problem of the road surface texture depth affecting the water film thickness detection results, making the detection results more accurate and reliable. Specifically, the road surface texture image acquisition device 6 can be a 3D laser road surface texture scanner.

[0075] In some embodiments, such as Figure 6 As shown, the single arm 11 of the multi-arm robotic arm is rotatably connected to the corresponding connecting rod 9 via a rotating shaft 12;

[0076] The connecting rods 9 are divided into two groups. The connecting rods 9 on the left side are fixedly connected to the first rotating component, and the connecting rods 9 on the right side are fixedly connected to the second rotating component. When the first rotating component and the second rotating component rotate, they can drive the corresponding connecting rods 9 to rotate horizontally, which in turn drives the corresponding single arm 11 of the multi-arm robotic arm to rotate.

[0077] like Figure 7 As shown, a movable guide rail is installed on the outer cover 1. The first rotating component and the second rotating component are mounted on the movable guide rail through a connecting plate 8. The connecting plate 8 can move up and down along the movable guide rail, driving the multi-arm robotic arm and probe to move vertically up and down inside the outer cover 1.

[0078] In some embodiments, both the first rotating component and the second rotating component are bearings mounted in bearing housings.

[0079] In some embodiments, the rotation and movement of the multi-arm robotic arm are controlled remotely for convenient operation.

[0080] In some embodiments, when detecting the thickness of the water film, the probes are spread out in a square distribution under the control of the multi-arm robotic arm. The diagonal length of the square where the probes are distributed is less than the side length of the scanning area of ​​the road surface texture image acquisition device 6, so that the measured area is completely covered by the three-dimensional cloud map of the road surface texture.

[0081] In some embodiments, a plurality of mounting holes 10 with snap-fit ​​are evenly provided on a single arm 11 of the multi-arm robotic arm;

[0082] The probe is vertically and detachably installed in the mounting hole 10 via a snap fastener. The length reserved at the lower end of the probe can be adjusted according to different regions and different rainfall conditions.

[0083] In some embodiments, the highway surface water film thickness detection device is characterized in that it further includes:

[0084] The camera system 4 is used to capture images of the water film thickness detection structure 3 and transmit them to the data processing module. The data processing module identifies the length of the color change of the water-sensitive coating on the water film thickness detection structure 3 based on the images of the water film thickness detection structure 3.

[0085] In some embodiments, all probes on the multi-arm robotic arm are staggered, such as... Figure 6 As shown, this is so that the camera system 4 can identify the length of the color change of the water-sensitive coating on each probe.

[0086] In some embodiments, the highway surface water film thickness detection device is characterized in that it further includes:

[0087] The power supply module 7 provides operating voltage for the electrical components of the highway surface water film thickness detection device. The power supply module 7 may be a storage battery and / or a battery pack.

[0088] In some embodiments, the outer cover 1 is a transparent cubic structure with an open bottom, and its four corners are provided with support legs to facilitate the smooth flow of water, ensuring that the thickness of the water film inside the outer cover 1 is consistent with the thickness of the water film on the road surface, and avoiding the outer cover 1 causing inconsistent thickness of the water film inside and outside.

[0089] In some embodiments, the outer cover 1 is provided with two partitions 5, which are arranged in relation to two opposite side plates near the outer cover 1. Each partition 5 and the side plate near it form a bottom-sealed receiving cavity, in which the camera system 4 and the power supply module 7 are placed.

[0090] Example 2

[0091] This embodiment provides a method for detecting the thickness of a road surface water film, using the road surface water film thickness detection device described in Embodiment 1, and includes the following steps:

[0092] Step S1: Apply the water-sensitive color-changing coating evenly to the probe, which serves as the support structure for the water film thickness detection structure 3, to form a water-sensitive color-changing coating.

[0093] Step S2: Under rainfall conditions, place the road surface water film thickness detection device in an area where the road surface water film is thicker and mark the center of that area;

[0094] Step S3: Manipulate the first and second rotating parts of the multi-arm robotic arm to spread the probes out into a square distribution. Then, manipulate the multi-arm robotic arm to descend, and the probe tips will insert into the ground. The water-sensitive color-changing coating of the probe will change color when it encounters the water film on the ground. Then, manipulate the multi-arm robotic arm to lift the probes to the camera system 4. The camera system 4 will capture images of the probes and transmit them to the data processing module. The data processing module will analyze and process the images captured by the camera system 4 and determine the length of the color change of the water-sensitive color-changing coating of the probe based on image recognition.

[0095] Step S4: The data processing module establishes a coordinate system XYZ with the ground point where any probe is located as the origin. The XY plane is parallel to the road surface and the Z axis is perpendicular to the road surface. The coordinate values ​​of each probe's measuring point are obtained. The Z value of each measuring point is the length of the color change of the water-sensitive coating of the corresponding probe.

[0096] Step S5: After the road surface dries, place the road surface water film thickness detection device back into the area to be measured according to the location of the marked points. Operate the first and second rotating components of the multi-arm robotic arm, causing the single arm 11 of the multi-arm robotic arm to move the probes in two groups to retract at the two adjacent side plates of the outer cover 1. Figure 2 As shown; the road surface texture image acquisition device 6 is activated to acquire the ground surface texture, obtain a three-dimensional cloud map of the road surface texture, and transmit it to the data processing module;

[0097] Step S6: The data processing module processes the 3D cloud map of the road surface texture and captures the origin of the XYZ coordinate system established in step S4. Based on the origin and the coordinate values ​​of each measuring point, the range of the measured area is extracted. Within the range of the measured area, a coordinate system XYZ based on the road surface texture depth is established using the origin of the XYZ coordinate system. ’ Z-coordinates of each measuring point ’ The value is the surface texture depth value at that measuring point;

[0098] Step S7: The data processing module obtains the water film thickness value Z at each measuring point based on the following formula. ’’ :

[0099] Z ’’ = ZZ ’ ;

[0100] Where Z is the length of the color change of the water-sensitive coating on the probe at each measuring point, Z ’ The surface texture depth value at each measuring point;

[0101] Step S8: Take the water film thickness value Z at each measuring point. ’’ The average value is used as the current road surface water film thickness detection value.

[0102] In some embodiments, to eliminate the influence of capillary action in water-sensitive color-changing coatings on the measurement of water film thickness, a calibration test needs to be performed beforehand:

[0103] Use a graduated cylinder to measure water to a certain depth, insert a probe coated with a water-sensitive color-changing coating into the water, then take it out and measure its length with a vernier caliper. Compare the measured length with the initially determined water depth to obtain the difference.

[0104] Multiple sets of the above tests were conducted, and the average value of the differences obtained from the multiple sets of tests was taken. The average value of the differences was then used to calibrate the test results of the water film thickness.

[0105] In some embodiments, a coordinate system is established with the forward direction of driving as the X-axis, the road width from the central divider to the shoulder as the Y-axis, and the direction perpendicular to the road surface as the Z-axis. By reading the coordinate values ​​of the measuring points where each probe is located, it can be ensured that the measured area is completely covered by the three-dimensional cloud map of the road surface texture.

[0106] In some embodiments, the long side of the outer cover 1 is placed in the road width direction and the short side is placed in the driving direction, and a coordinate system is established with the long side as the Y-axis and the short side as the X-axis.

[0107] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A device for detecting the thickness of a film of water on a road surface, characterised in that, include: The outer cover (1) has an opening at the bottom, and water can flow smoothly through the bottom of the outer cover (1); Water film thickness detection structure (3) is set inside the outer cover (1). The water film thickness detection structure (3) is a water-sensitive color-changing coating applied to the support structure. The length of the color change of the water-sensitive coating after the bottom of the support structure comes into contact with the road surface is the water film thickness value. The water film thickness detection structure (3) uses multiple probes coated with a water-sensitive color-changing coating; Multiple probes are detachably and vertically mounted on a single arm (11) of a multi-arm robotic arm, and all probes are staggered. The single arm (11) of the multi-arm robotic arm is rotatably connected to the corresponding connecting rod (9) via a rotating shaft (12); The connecting rod (9) is divided into two groups. The connecting rod (9) on the left side is fixedly connected to the first rotating component, and the connecting rod (9) on the right side is fixedly connected to the second rotating component. The first rotating component and the second rotating component rotate, causing the connecting rod (9) and the single arm (11) to rotate horizontally inside the outer cover (1). The outer cover (1) is equipped with a moving guide rail. The first rotating component and the second rotating component are mounted on the moving guide rail via a connecting plate (8). The connecting plate (8) can move up and down along the moving guide rail, driving the multi-arm robotic arm and probe to move vertically up and down inside the outer cover (1).

2. The highway surface water film thickness detection device according to claim 1, characterized in that, A moving mechanism is installed inside the outer cover (1), and the water film thickness detection structure (3) is installed at the moving end of the moving mechanism; The moving mechanism can drive the water film thickness detection structure (3) to move vertically up and down inside the outer cover (1). The moving mechanism can manipulate the water film thickness detection structure (3) to move to its bottom end to contact the road surface.

3. The highway surface water film thickness detection device according to claim 1, characterized in that, The water film thickness detection structure (3) is installed on the robotic arm (2). The water film thickness detection structure (3) moves vertically up and down as the robotic arm (2) rises and falls.

4. A highway surface water film thickness detection device according to claim 2 or 3, characterized in that, The water film thickness detection structure (3) is provided with multiple components; Multiple water film thickness detection structures (3) are vertically mounted on the single arm (11) of the multi-arm robotic arm.

5. The highway surface water film thickness detection device according to claim 1, characterized in that, The multi-arm robotic arm has multiple mounting holes (10) with buckles evenly arranged on each arm (11). The probe is vertically and detachably installed in the mounting hole (10) via a snap fastener.

6. A highway surface water film thickness detection device according to any one of claims 1 to 3 or 5, characterized in that, Also includes: The road surface texture image acquisition device (6) acquires a three-dimensional cloud map of the road surface texture of the measured area and transmits it to the data processing module. The data processing module identifies the road surface texture depth value of the measured area based on the three-dimensional cloud map of the road surface texture of the measured area, and then subtracts the road surface texture depth value from the color change length of the water-sensitive coating to obtain the actual water film thickness value.

7. A highway surface water film thickness detection device according to any one of claims 1 to 3 or 5, characterized in that, Also includes: The camera system (4) is used to capture images of the water film thickness detection structure (3) and transmit them to the data processing module. The data processing module identifies the length of the color change of the water film thickness detection structure (3) when it comes into contact with water based on the images of the water film thickness detection structure (3). Power supply module (7), which provides operating voltage to electrical components; The outer cover (1) is a transparent cubic structure with an open bottom, and its four corners are provided with support legs; The outer cover (1) is provided with two partitions (5), which are provided in relation to two opposite side plates near the outer cover (1). Each partition (5) and the side plate near it form a bottom-sealed receiving cavity, in which a camera system (4) and a power supply module (7) are placed.

8. A method for detecting the thickness of a water film on the road surface, characterized in that, The method of using a road surface water film thickness detection device according to any one of claims 1 to 7 includes the following steps: Step S1: Apply the water-sensitive color-changing coating evenly to the probe, which serves as the support structure for the water film thickness detection structure (3), to form a water-sensitive color-changing coating. Step S2: Under rainfall conditions, place the road surface water film thickness detection device in an area where the road surface water film is thicker and mark the center of that area; Step S3: Manipulate the multi-arm robotic arm to spread the probes out into a square distribution. The diagonal length of the square where the probes are distributed is less than the side length of the scanning area of ​​the road texture image acquisition device (6). Manipulate the multi-arm robotic arm to descend, and the probe tip is inserted into the ground. The water-sensitive color-changing coating of the probe changes color when it comes into contact with the water film on the ground. Then manipulate the multi-arm robotic arm to drive the probe to the camera system (4). The camera system (4) captures the image of the probe and transmits it to the data processing module. The data processing module analyzes and processes the image captured by the camera system (4) and determines the length of the color change of the water-sensitive color-changing coating of the probe based on image recognition. Step S4: The data processing module establishes a coordinate system XYZ with the ground point where any probe is located as the origin. The XY plane is parallel to the road surface and the Z axis is perpendicular to the road surface. The coordinate values ​​of each probe's measuring point are obtained. The Z value of each measuring point is the length of the color change of the water-sensitive coating of the corresponding probe. Step S5: After the road surface dries, place the road surface water film thickness detection device back in the area to be measured according to the position of the marked point. Operate the multi-arm robotic arm to retract the probe to the side plate of the outer cover (1), and start the road surface texture image acquisition device (6) to acquire the ground surface texture and obtain a three-dimensional cloud map of the road surface texture, which is then transmitted to the data processing module. Step S6: The data processing module processes the 3D cloud map of the road surface texture and captures the origin of the XYZ coordinate system established in step S4. Based on the origin and the coordinate values ​​of each measuring point, the range of the measured area is extracted. Within the measured area, a coordinate system based on the road surface texture depth is established using the origin of the XYZ coordinate system. Z-coordinates of each measuring point ’ The value is the surface texture depth value at that measuring point; Step S7: The data processing module obtains the water film thickness value at each measuring point based on the following formula. : ； Where Z is the length of the color change of the water-sensitive coating on the probe at each measuring point, Z ’ The surface texture depth value at each measuring point; Step S8: Take the water film thickness value Z at each measuring point. ’’ The average value is used as the current road surface water film thickness detection value.

9. The method for detecting the thickness of a road surface water film according to claim 8, characterized in that, To eliminate the influence of capillary action in water-sensitive paints on the measurement of water film thickness, a calibration test needs to be conducted beforehand. Use a graduated cylinder to measure water to a certain depth, insert a probe coated with a water-sensitive color-changing coating into the water, then take it out and measure its length with a vernier caliper. Compare the measured length with the initially determined water depth to obtain the difference. Multiple sets of the above tests were conducted, and the average value of the differences obtained from the multiple sets of tests was taken. The average value of the differences was then used to calibrate the test results of the water film thickness.

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