A compaction monitoring device and method integrating 3D scanning and image perception

Abstract

The present invention relates to a compaction monitoring device and method that integrates 3D scanning and image perception. The device comprises a sensing component comprised of a 3D road surface texture scanning module, a camera, a vibration damping module, and a locator; a data analysis component, which performs image positioning, image stitching, time synchronization, and calculation of a compaction index based on texture features; and a control strategy component, which controls the number of compaction attempts based on the surface distribution of the compaction index. Compared to existing technologies, this invention introduces a new information source and evaluation basis for road compaction, enabling dynamic, real-time monitoring and feedback control of compaction levels, improving the quality of road construction projects and enabling compaction monitoring based on 3D scanning and image perception.

Description

Technical Field

[0001] The present invention relates to the technical field of road surface monitoring, and in particular to a compaction monitoring device and method integrating three-dimensional scanning and image perception. Background Art

[0002] During asphalt pavement construction, compaction is a crucial step and one of the most significant factors, directly impacting the pavement's strength, stiffness, road performance, and durability. Effective compaction is essential to ensure sufficient strength and stiffness, ensuring smoothness and durability. The "Asphalt Pavement Construction and Acceptance Standards" set strict requirements for construction techniques, performance indicators, and acceptance criteria during asphalt pavement compaction. The quality of asphalt pavement compaction is closely linked to premature pavement failure, with poor compaction quality being one of the primary causes of premature pavement failure.

[0003] Traditional methods for testing the compaction quality of asphalt pavements rely primarily on post-acceptance, including destructive and non-destructive sampling methods. Destructive sampling, primarily involving core sampling, is time-consuming and labor-intensive, with complex procedures and damage to the pavement, resulting in extremely low efficiency. Non-destructive sampling, primarily involving nuclear and non-nuclear densitometers, can only monitor the degree of compaction and, as a sampling method, are difficult to accurately represent the compaction quality of the entire surface layer. The shortcoming of post-acceptance is that it cannot accurately and completely reflect the actual compaction status of the asphalt pavement in real time, resulting in under- or over-pressure at the construction site and the inability to make real-time adjustments during construction.

[0004] In recent years, both domestic and international research has been actively exploring more real-time and effective methods for controlling and monitoring asphalt pavement compaction quality. Intelligent compaction primarily relies on compaction machinery to control compaction quality. It can be applied to control the compaction quality of all layers of road construction materials, including subgrade, base course, and surface layers. Current applications primarily focus on compaction parameters such as vibration frequency, acceleration, displacement, strain, and stress during the compaction process. However, monitoring pavement texture and morphology during compaction is still less mature.

[0005] Chinese patent application number CN202021556134.9 provides a roadbed and pavement compaction monitoring device for a highway engineering project, including a compaction sensor, an infrared temperature sensor, a positioning device and a compaction controller; several compaction sensors are arranged on the vibrating wheel of the roller, the infrared temperature sensor is arranged at the bottom of the roller, a positioning device is arranged on the top of the roller, and the compaction controller is arranged on the roller body; the compaction sensor, the infrared temperature sensor and the positioning device are all connected to the compaction controller through a communication cable.

[0006] The above application can provide feedback on compaction and temperature parameters to provide compaction information and guidance to the operator. However, the above application cannot monitor the pavement texture during the compaction process. Summary of the Invention

[0007] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and to provide a compaction monitoring device and method that integrates three-dimensional scanning and image perception, so as to realize compaction degree monitoring based on three-dimensional scanning and image perception.

[0008] The purpose of the present invention can be achieved by the following technical solutions:

[0009] One aspect of the present invention provides a compaction monitoring device that integrates three-dimensional scanning and image perception, which is installed on a road roller and is used to monitor the texture of the road surface during the compaction process. The compaction monitoring device includes:

[0010] A shock-absorbing module is provided on the roller;

[0011] A control terminal connected to the shock absorption module;

[0012] a three-dimensional scanning module, connected to the shock absorption module and the control terminal respectively, for collecting three-dimensional texture data of the road surface;

[0013] A camera, connected to the vibration reduction module and the control terminal, respectively, for collecting image data of the scanning area during the three-dimensional scanning process and performing fine positioning through image matching;

[0014] Locator, used to collect location data.

[0015] As a preferred technical solution, the shock absorption module includes a stabilizing pan / tilt platform.

[0016] As a preferred technical solution, the three-dimensional scanning module includes a laser and a stereo camera.

[0017] As a preferred technical solution, the control terminal is arranged and connected to one end of the shock-absorbing module, the camera and the three-dimensional scanning module are arranged and connected to the extension section of the same end of the shock-absorbing module, and the other end of the shock-absorbing module is fixedly connected to the roller.

[0018] As a preferred technical solution, the control terminal, three-dimensional scanning module and camera are arranged on the same straight line.

[0019] As a preferred technical solution, the center of gravity of the assembly formed by the control terminal, the three-dimensional scanning module and the camera falls on the horizontal projection plane of the shock absorption module.

[0020] As a preferred technical solution, the locator is connected to the control terminal and is used to collect position data of the roller.

[0021] As a preferred technical solution, with the moving direction of the roller as the forward direction, the compaction monitoring equipment is arranged on the rear side of the roller.

[0022] Another aspect of the present invention provides a compaction monitoring method applied to the compaction monitoring device integrating three-dimensional scanning and image perception as described above, comprising the following steps:

[0023] Collecting 3D texture data, image data and position data from the 3D scanning module, camera and locator respectively;

[0024] The roller is roughly located based on the position data. During the first operation, the image data is used to perform full-area splicing. During repeated compaction, the image data is used to extract image features and perform matching to achieve fine positioning.

[0025] The average profile depth of the road surface is calculated based on the three-dimensional texture data and used as a compaction index. The depth is correlated with the positioning result through time synchronization to reflect the index status in real time.

[0026] As a preferred technical solution, the following steps are also included:

[0027] The number of compaction times is controlled based on the indicator threshold when the compaction is sufficient.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] (1) Realize compaction degree monitoring based on three-dimensional scanning and image perception: Unlike existing solutions that use compaction sensors to evaluate compaction quality, this application sets a three-dimensional scanning module on the roller equipment, which can monitor the road surface texture morphology during the compaction process and more clearly reflect the compaction results based on the existing compaction degree evaluation. By setting up a camera, the current position of the roller can be accurately located through image matching, and the positioning result can be more accurately associated with the compaction degree.

[0030] (2) High accuracy of collected data: This application additionally sets up a shock absorption module, which includes a stabilizing gimbal or a tuned mass damper, which can reduce the impact of vibration on the sensor. At the same time, in order to avoid the problem of the center of gravity of the structure shifting and causing the shock absorption effect to deteriorate or even fail, the relative positions of the control terminal, the three-dimensional scanning module and the camera are adjusted so that the center of gravity of the combination formed by the three falls on the horizontal projection plane of the shock absorption module. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1Schematic diagram of the composition of an intelligent compaction device integrating three-dimensional scanning and image perception in an embodiment;

[0032] Figure 2 A schematic diagram of the deployment of intelligent compaction equipment integrating 3D scanning and image perception in an embodiment;

[0033] Figure 3 This is a design architecture diagram of an intelligent compaction device that integrates three-dimensional scanning and image perception in an embodiment;

[0034] Figure 4 Schematic diagram of calculating the average profile depth of the road surface;

[0035] Figure 5 Convergence law of compaction degree index,

[0036] Among them, 1. road roller, 2. shock absorption module, 3. control terminal, 4. three-dimensional scanning module, 401. laser, 402. stereo camera, 5. camera, 6. locator. DETAILED DESCRIPTION

[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0038] In view of the shortcomings of the above background technology, the present invention provides a compaction monitoring device and method that integrates three-dimensional scanning and image perception to solve the problems in the prior art.

[0039] See also Figure 1 , the present invention comprises the following three parts:

[0040] (1) Perception part: The perception part includes a road surface texture three-dimensional scanning module, a camera, and is equipped with a shock absorption module and a locator.

[0041] The perception part is deployed at the back end of the roller, and collects data along the direction of travel during the roller operation. The collected data is connected to the control terminal, which deploys software modules for data analysis and control strategies to store, process and control the compaction strategy. The control strategy is displayed on the control terminal interface to assist operators in making decisions on the number of compaction times. The perception part is deployed at the back end of the roller, and collects data along the direction of travel during the roller operation. The functions and relationships of its modules are shown in the attached figure. Figure 3 shown.

[0042] The 3D scanning module can follow the movement of the roller, preferably using the principle of triangulated laser ranging, utilizing line lasers and stereo cameras to acquire a 3D point cloud of the road surface. This dynamically captures high-resolution 3D road surface texture information with x, y, and z coordinates. By connecting the encoder to the vehicle, the vehicle's travel distance is measured, which controls the laser line reading rate. The 3D scanning module can capture the road surface's macroscopic texture, with a wavelength range of 0.5mm to 50mm. The horizontal and vertical data sampling intervals should be less than 0.5mm, and the depth sampling accuracy should be less than 0.5mm.

[0043] The camera captures a large area of ​​the road surface from a bird's-eye view. The image only contains the road surface and no other objects appear. The image resolution must meet the requirements of identifying the morphological characteristics of the road surface particles.

[0044] The shock absorption module may include shock absorption damping, stabilization pan and tilt components, etc., which can effectively reduce the vibration of the vehicle itself during operation of the roller and reduce the error of three-dimensional scanning.

[0045] The locator can dynamically obtain longitude and latitude positioning information with a positioning accuracy of no less than 2 meters.

[0046] (2) Data analysis part: The data analysis part includes image positioning, image stitching, time synchronization, and calculation of compaction index based on texture features.

[0047] The data analysis part uses a locator for coarse positioning and uses image data to perform full-area stitching during the first operation. An encoder is installed on the roller's moving wheels so that the camera does not take images repeatedly, and the encoder is used to stitch continuous images to realize the collection area.

[0048] The data analysis part uses image feature matching to perform fine positioning during the repeated compaction process. First, the positioning data is screened and the positioning information is associated with the 3D scanning data through time synchronization.

[0049] The data analysis part is based on the calculation of the compaction index of texture characteristics, and uses three-dimensional scanning data for analysis to obtain the compaction index that reflects the texture characteristics of the road surface.

[0050] The data analysis part is based on the calculation of the compaction degree index of texture characteristics. The index is a parameter that can reflect the apparent characteristics of the texture. The parameters include but are not limited to the average structural depth MTD of the pavement, the average profile depth MPD of the pavement, the average height Ra, the root mean square height Rq, the arithmetic mean slope Da, the root mean square slope Dq, the arithmetic mean wavelength La, the root mean square wavelength Lq, the skewness Ssk, the kurtosis Sku, the maximum peak height Sp, and the maximum valley depth Sv.

[0051] In this embodiment, the data analysis part uses the pavement mean profile depth (MPD) to calculate the compaction index based on the texture characteristics. MPD is calculated for each cross-section contour line. Each contour line is divided into two equal segments. The mean of the peak values ​​of the two segments and the difference between the mean values ​​of the two segments are calculated. The MPD is then averaged for each contour line. The calculation diagram is shown below. Figure 4 As shown, the calculation formula is:

[0052]

[0053] Where MPD is the mean profile depth; h1 is the peak height of the first half of the profile; h2 is the peak height of the first half of the profile; h is the average height of the entire profile; and n is the number of profiles.

[0054] (3) Control strategy part: The control strategy part controls the number of compaction times according to the surface distribution of the compaction degree index.

[0055] The control strategy part extracts statistical indicators such as the mean, extreme value, and standard deviation of the compacted pavement indicators for analysis based on the distribution of compaction degree indicators based on texture characteristics in the compacted area.

[0056] The control strategy part reflects the indicator status in real time and controls the compaction times based on the indicator threshold based on texture features when the compaction is sufficient.

[0057] Among them, the indicator threshold under the condition of sufficient compaction is obtained based on experiments. During the pavement compaction process, corresponding data is collected. As the compaction times accumulate, the change pattern of the observed indicators is observed. According to the experience of traditional compaction times and the convergence status of the compaction indicators based on texture features, the control threshold of the compaction indicators based on texture features is determined.

[0058] See also Figure 2 This is a schematic diagram of the specific structure of the compaction monitoring device that integrates 3D scanning and image perception in this embodiment. With the direction of travel of the roller 1 as the forward direction, the compaction monitoring device that integrates 3D scanning and image perception is set at the rear side of the roller 1. The compaction monitoring device includes:

[0059] The shock absorption module 2 is provided on the roller 1, which can effectively reduce the vibration of the roller itself during operation and reduce the error of three-dimensional scanning;

[0060] The control terminal 3 is connected to the shock absorption module 2;

[0061] A three-dimensional scanning module 4 is connected to the vibration reduction module 2 and the control terminal 3 respectively, and is used to collect three-dimensional texture data of the road surface. The three-dimensional scanning module 4 includes a laser 401 and a stereo camera 402;

[0062] The camera 5 is connected to the vibration reduction module 2 and the control terminal 3 respectively, and is used to collect image data of the scanning area during the three-dimensional scanning process;

[0063] The locator 6 is connected to the control terminal 3 and is used to collect position data of the road roller 1 .

[0064] The control terminal 3 is set and connected to one end of the shock absorption module 2, the camera 5 and the three-dimensional scanning module 4 are set and connected to the extension section of the same end of the shock absorption module 2, and the other end of the shock absorption module 2 is fixedly connected to the roller 1.

[0065] The control terminal 3, 3D scanning module 4, and camera 5 are arranged in a straight line, with the center of gravity of the assembly formed by the three falling on the horizontal projection plane of the shock-absorbing module 2. The combined mass of the extended section of the shock-absorbing module 2, the camera 5, and the 3D scanning module 4 is less than the mass of the assembly of the positioner 6 and the control terminal 3. By adjusting the relative positions of these components, the center of gravity of the control terminal 3, 3D scanning module 4, and camera 5 can be adjusted to fall on the horizontal projection plane of the shock-absorbing module. The center of gravity should be positioned appropriately from the top of the shock-absorbing module to prevent it from shaking.

[0066] When shock absorption module 2 utilizes a tuned mass damper (TMD), the damper comprises a mass, a spring, and a damping system consisting of four dampers. The dampers are arranged in a rectangular shape. By adjusting the relative positions of the control terminal, 3D scanning module, and camera, the center of gravity of the resulting assembly falls on the horizontal projection plane of the TMD. This overcomes the problem of structural center of gravity shift, which can lead to reduced or even ineffective shock absorption. The center of gravity should be positioned appropriately from the top of the shock absorption module, and the damping coefficient of the damper should be appropriately selected to prevent shaking.

[0067] When the shock absorption module 2 adopts a stabilizing pan-tilt platform, it is powered by the power supply of the roller 1 to ensure that the distance between the three-dimensional scanning module 4 and the camera 5 and the ground is fixed.

[0068] See also Figure 3 , the compaction monitoring method comprises the following steps:

[0069] Step S1, collecting 3D texture data, image data and position data from the 3D scanning module, camera and locator respectively;

[0070] Step S2: Coarsely locate the roller based on the position data. During the first operation, the image data is used for full-area splicing. During repeated compaction, the image data is used to extract image features and perform matching to achieve fine positioning.

[0071] Step S3, calculate the average profile depth of the road surface based on the three-dimensional texture data as a compaction index, associate it with the positioning result through time synchronization, reflect the index status in real time, and control the compaction times based on the index threshold under the condition of sufficient compaction.

[0072] Compared with the prior art, the present invention has the following advantages:

[0073] (1) The method of the present invention is based on the apparent texture changes of the asphalt surface layer during the compaction stage, and proposes a device and system for real-time monitoring and control of the compaction process, which effectively transfers the compaction construction management from post-inspection to process control.

[0074] (2) The system provided by the present invention is lightweight and convenient, and can achieve rapid and non-destructive scanning of the asphalt surface layer during the compaction stage, which helps promote the digital development of road construction.

[0075] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and such modifications or substitutions are intended to be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the scope of protection of the claims.

Claims

1. A compaction monitoring method applied to a compaction monitoring device integrating three-dimensional scanning and image perception, characterized in that: The compaction monitoring device is provided on the road roller (1) and is used to monitor the road surface texture during the compaction process. The compaction monitoring device comprises: A shock-absorbing module (2) is arranged on the road roller (1); A control terminal (3) connected to the shock absorption module (2); A three-dimensional scanning module (4), connected to the shock absorption module (2) and the control terminal (3), respectively, for collecting three-dimensional texture data of the road surface; A camera (5) is connected to the vibration reduction module (2) and the control terminal (3), respectively, and is used to collect image data of the scanning area during the three-dimensional scanning process and perform fine positioning through image matching; Locator (6), used to collect position data, The compaction monitoring method comprises the following steps: Collecting three-dimensional texture data, image data, and position data from the three-dimensional scanning module (4), the camera (5), and the locator (6) respectively; Based on the position data, the position of the roller (1) is roughly positioned; during the first operation, the image data is used for full-area splicing; during repeated compaction, the image data is used to extract image features and perform matching to achieve fine positioning; The average profile depth of the road surface is calculated based on the three-dimensional texture data and used as a compaction index. The depth is correlated with the positioning result through time synchronization to reflect the index status in real time.

2. The compaction monitoring method for compaction monitoring equipment integrating three-dimensional scanning and image perception according to claim 1, characterized in that: The shock absorption module (2) includes a stabilizing platform.

3. The compaction monitoring method for compaction monitoring equipment integrating three-dimensional scanning and image perception according to claim 1, characterized in that: The three-dimensional scanning module (4) includes a laser (401) and a stereo camera (402).

4. The compaction monitoring method for compaction monitoring equipment integrating three-dimensional scanning and image perception according to claim 1, characterized in that: The control terminal (3) is arranged and connected to one end of the shock absorbing module (2), the camera (5) and the three-dimensional scanning module (4) are arranged and connected to an extension section of the same end of the shock absorbing module (2), and the other end of the shock absorbing module (2) is fixedly connected to the road roller (1).

5. The compaction monitoring method for compaction monitoring equipment integrating three-dimensional scanning and image perception according to claim 1, characterized in that: The control terminal (3), three-dimensional scanning module (4) and camera (5) are arranged on the same straight line.

6. The compaction monitoring method for compaction monitoring equipment integrating three-dimensional scanning and image perception according to claim 1, characterized in that: The center of gravity of the assembly formed by the control terminal (3), the three-dimensional scanning module (4) and the camera (5) falls on the horizontal projection plane of the shock absorbing module (2).

7. The compaction monitoring method for compaction monitoring equipment integrated with three-dimensional scanning and image perception according to claim 1, characterized in that: The locator (6) is connected to the control terminal (3) and is used to collect position data of the road roller (1).

8. The compaction monitoring method for compaction monitoring equipment integrated with three-dimensional scanning and image perception according to claim 1, characterized in that: Taking the moving direction of the road roller (1) as the forward direction, the compaction monitoring device is arranged on the rear side of the road roller (1).

9. The compaction monitoring method for compaction monitoring equipment integrated with three-dimensional scanning and image perception according to claim 1, characterized in that: The following steps are also included: The number of compaction times is controlled based on the indicator threshold when the compaction is sufficient.

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