Asphalt pavement temperature field scanner

Abstract

The invention discloses an asphalt pavement temperature field scanner, and the scanner comprises at least two thermal imaging modules which are horizontally arranged in a direction perpendicular to the paving advancing direction of an asphalt pavement, the effective view fields of the thermal imaging modules cover the cross section of the asphalt pavement, and the view fields of the projections of the adjacent thermal imaging modules on the asphalt pavement are overlapped; the synchronous acquisition module is used for synchronously triggering each thermal imaging module to synchronously acquire the infrared image of the asphalt pavement with the same time reference; and the embedded processing unit is used for carrying out geometric distortion correction on the infrared images of the asphalt pavement synchronously acquired by the thermal imaging modules, executing infrared radiation consistency compensation, image registration, fusion and conversion, and generating and outputting temperature data covering the temperature distribution of the cross section of the asphalt pavement. According to the invention, high-resolution, low-cost and real-time temperature imaging of the cross section of the ultra-wide asphalt pavement is realized, and reliable data support is provided for construction quality.

Description

Technical Field

[0001] This invention belongs to the field of construction quality testing technology, and in particular relates to an asphalt pavement temperature field scanner. Background Technology

[0002] During asphalt pavement construction, "full-section, high-precision, and real-time" temperature monitoring of the pavement surface is essential. National high-grade highways are gradually developing towards 10-lane dual carriageways. Due to the very wide pavements, drainage asphalt is required to prevent large-scale water accumulation. This ultra-wide asphalt pavement construction places very clear and strict requirements on the temperature standards of the asphalt materials at each stage. The uniformity of pavement temperature distribution directly affects the pass rate of mixture compaction. However, current asphalt pavement temperature monitoring technology in the industry faces significant bottlenecks: 1. Traditional testing methods rely on manual on-site operation and have low sample density: Manual measurement using an insertion thermometer or more than three tests using a non-contact temperature sensor both require manual operation, which affects construction efficiency. At the same time, the number of samples is very small. In the entire process of paving ultra-wide roads, the temperature distribution of asphalt materials is a very discrete system. Relying on manual temperature measurement cannot effectively reflect the true temperature of asphalt materials at the construction site. 2. Mechanical temperature scanning has a complex structure and a long scanning cycle, and cannot present the infrared details of the road surface: In order to improve the temperature measurement efficiency and sample density, it is necessary to perform cross-sectional temperature scanning on the road surface. Some solutions use a mechanical rotating mechanism to drive the non-contact infrared temperature sensor to swing laterally to achieve cross-sectional scanning of the road surface. This mechanical scanning method has a complex structure and is easily affected by the vibration of the paver. When the paving width is large, the scanning cycle is long and the accuracy is difficult to meet. Although it is an improvement over the manual method, it can still only reflect the overall temperature trend of the road surface in a general way and cannot present the infrared characteristics of the road surface, such as the low temperature anomaly points caused by condensation blocks commonly seen in construction, or V-shaped temperature segregation. 3. Difficulty in balancing the economic efficiency and coverage of thermal imaging solutions: Some solutions also use optical infrared thermal imaging lenses to scan the road surface temperature. This solution can achieve a high scanning cycle and display the infrared details of the road surface. However, the price of thermal imaging lenses increases several times with the resolution. Very expensive equipment is required to achieve cross-sectional temperature scanning of ultra-wide lanes on current high-grade highways. Furthermore, the scanning results need to be stored based on thermal imaging photos, which requires huge storage space and is not conducive to the transmission and analysis of temperature data. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide an asphalt pavement temperature field scanner to achieve high-resolution, low-cost, real-time temperature imaging of ultra-wide asphalt pavement cross sections.

[0004] To solve the above-mentioned technical problems, the present invention is implemented using the following solution: This invention provides an asphalt pavement temperature field scanner, comprising: The thermal imaging module is set to no less than two units, arranged horizontally along the direction perpendicular to the asphalt pavement paving direction, and its effective field of view covers the cross section of the asphalt pavement. The synchronous acquisition module is used to synchronously trigger each thermal imaging module to acquire infrared images of asphalt pavement at the same time reference. The embedded processing unit is used to perform geometric distortion correction, infrared radiation consistency compensation, image registration, fusion and conversion on the infrared images of asphalt pavement synchronously acquired by each thermal imaging module, and generate temperature data covering the cross-sectional temperature distribution of the asphalt pavement for output.

[0005] Furthermore, the temperature measurement range of the thermal imaging module is -20℃ to +500℃.

[0006] Furthermore, the spatial resolution requirement for thermal imaging modules is to achieve an equivalent sampling density of 1-10 cm / pixel.

[0007] Furthermore, the overlap ratio of the fields of view of adjacent thermal imaging modules projected onto the asphalt pavement is 10%-30%.

[0008] Furthermore, the thermal imaging module has a frame rate of 1-50Hz.

[0009] Furthermore, image registration is accomplished using feature point matching, phase correlation, or template matching.

[0010] Furthermore, the temperature data can be either one-dimensional temperature data or a two-dimensional temperature image.

[0011] Furthermore, the temperature data is in the format of CSV, binary array, or compressed heatmap.

[0012] Furthermore, it also includes a protective housing, on which the thermal imaging module is mounted, and inside which the synchronous acquisition module and the embedded processing unit are mounted. Beneficial effects

[0013] This invention, by pre-setting the number of thermal imaging modules, can cover asphalt pavement with a paving width of 6-24 meters, and the scanning width covers different road construction needs; it uses multiple miniature thermal imaging modules to replace a single high-end thermal imager, significantly reducing costs; the thermal imaging modules have an equivalent sampling density of centimeters, which can effectively identify quality defects such as temperature segregation and condensation anomalies; the output is structured temperature data rather than raw images, the data volume is small, which is convenient for edge computing and remote transmission; it supports high-speed continuous acquisition, meeting the needs of continuous cross-section monitoring under asphalt pavement paving operation speed; it has no moving parts, an all-solid-state structure, and high reliability. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of an asphalt pavement temperature field scanner provided in Embodiment 1 of the present invention; Figure 2 This is a schematic diagram illustrating the working principle of a thermal imaging module in an asphalt pavement temperature field scanner provided in Embodiment 1 of the present invention. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention. Example 1

[0016] like Figure 1 As shown, this embodiment provides an asphalt pavement temperature field scanner, including: N thermal imaging modules, where N is an integer greater than or equal to 2, are fixedly installed on the same rigid support and arranged horizontally along the direction perpendicular to the asphalt pavement paving. The fields of view of adjacent thermal imaging modules partially overlap in the pavement projection area. The value of N is predetermined in the equipment design stage based on the paving width of the asphalt pavement to be tested, so that the total effective field of view after splicing can completely cover the entire paving cross section. The synchronous acquisition module is used to synchronously trigger all thermal imaging modules to acquire infrared images with the same time reference. The acquisition frame rate of the thermal imaging modules is 1-50 Hz. The embedded processing unit is configured to sequentially perform geometric distortion correction, radiation consistency compensation, image registration based on overlapping areas, fusion and transformation on the multi-channel infrared images acquired by each thermal imaging module, and generate temperature data characterizing the temperature distribution of the entire paving cross section. The data output interface is used to output temperature data in a structured, lightweight format.

[0017] Specifically, such as Figure 2 As shown, the serialized design of different numbers of thermal imaging modules ensures that the stitched field of view of all modules can completely cover the entire paving cross section, and that adjacent modules retain a 10% to 30% overlap in the ground projection area, providing redundant information for subsequent image stitching. The thermal imaging module has a temperature measurement range of -20℃ to +500℃, completely covering the temperature range of asphalt mixture paving and possible abnormally high or low ambient temperature scenarios. Combined with a reasonable installation height and field of view design, the system can achieve an equivalent spatial sampling density of 1 cm to 10 cm per pixel on the road surface, which is sufficient to distinguish common quality defects in construction such as V-shaped temperature segregation, local condensation blocks, and material truck joints.

[0018] Each module achieves time synchronization through a synchronous acquisition module, ensuring that road surface temperature data is acquired at the same moment, avoiding motion blur or temperature drift caused by time differences. The working frame rate of the thermal imaging module can be adjusted within the range of 1 Hz to 50 Hz, which is sufficient to match the travel speed of conventional pavers of 2–6 m / min, or the operating speed of double-drum rollers of 5–6 km / h, to achieve continuous cross-section scanning.

[0019] The scanner integrates an embedded processing unit, typically using an industrial-grade computing module. After receiving infrared images from various sources, the processing unit first performs lens distortion correction on each image through the distortion correction module to eliminate geometric distortion caused by the wide-angle optical system. Then, it performs radiation consistency compensation through the infrared radiation consistency compensation module: by using a built-in reference blackbody or cross-calibration algorithm, it corrects the temperature measurement deviation caused by manufacturing tolerances between different modules, so that the entire array outputs a unified temperature reference. Next, the spatial matching module uses the texture or temperature gradient features in the overlapping areas of adjacent images to complete image spatial registration using feature point matching, phase correlation, or template matching. On this basis, the image fusion module uses a preset image fusion strategy to eliminate seams and generate a seamless, continuous cross-sectional temperature image. Finally, the image conversion module converts the image into a structured lightweight data format, including a one-dimensional temperature array or a two-dimensional temperature image. The data format is CSV, binary array, or compressed heatmap, without the full pixel data of the original infrared image. For example, a one-dimensional temperature array T(x) indexed by horizontal position, where x is in centimeters and T(x) represents the surface temperature value at the corresponding position in degrees Celsius.

[0020] Since the temperature data no longer contains the pixel information of the original infrared image, but only retains the key temperature values, the data volume is reduced by more than 90% compared to the original heat map. This makes it easy to upload the data in real time to the vehicle-mounted industrial control computer or cloud quality monitoring platform via industrial Ethernet, 4G / 5G or Wi-Fi and CAN bus through the data output interface provided by the data transmission module. This data can be used to display temperature distribution curves in real time, automatically identify low-temperature segregation areas, and generate compaction quality warnings.

[0021] In addition, the scanner is encased in a protective shell with an IP65 or higher protection rating, effectively preventing dust and water damage. It also features heat dissipation fins or a forced-air cooling structure to withstand the harsh working conditions of asphalt paving sites, including high temperatures (ambient temperatures can reach over 60°C), strong vibrations, and high dust levels. The scanner is typically mounted on a lateral support structure 2 to 4 meters behind the screed of the asphalt paver, moving synchronously with the paver to complete temperature scanning of the mixture before it is compacted by the roller, thus providing timely quality feedback during construction.

[0022] In summary, the asphalt pavement temperature field scanner, by pre-setting the number of thermal imaging modules, can cover asphalt pavement with a paving width of 6-24 meters, covering different road construction needs. It uses multiple miniature thermal imaging modules instead of a single high-end thermal imager, significantly reducing costs. The thermal imaging modules achieve an equivalent sampling density at the centimeter level, effectively identifying quality defects such as temperature segregation and condensation anomalies. The output is structured temperature data rather than raw images, resulting in small data volume, facilitating edge computing and remote transmission. It supports high-speed continuous acquisition, meeting the continuous cross-sectional monitoring needs under asphalt pavement paving operation speeds. With no moving parts and an all-solid-state structure, it boasts high reliability. It offers advantages such as low cost, no moving parts, small data volume, and strong real-time performance, making it suitable for quality monitoring during the asphalt paving process of high-grade highways. Example 2

[0023] This embodiment provides a method for mounting an asphalt pavement temperature field scanner on a paver or roller, as detailed below: When using a paver as a mounting platform, a rigid crossbeam is installed on the paver's roof, extending towards the screed. At the end of the crossbeam is a temperature field scanner structure containing multiple thermal imaging modules. The mounting point has an tilt adjustment function, which can adjust the angle between the scanner's optical axis and the road surface. When using a road roller as a mounting platform, the scanner is installed at a predetermined angle on the front edge of the roof of the road roller cab, so that the optical axis of the scanner is at a preset angle to the road surface.

[0024] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. An asphalt pavement temperature field scanner, characterized by, The application relates to a temperature measurement system for asphalt pavement, which comprises the following parts: a plurality of thermal imaging modules arranged horizontally along the direction perpendicular to the paving direction of the asphalt pavement, the effective field of view of the thermal imaging modules covering the cross section of the asphalt pavement and the field of view projected by the adjacent thermal imaging modules on the asphalt pavement overlapping; a synchronous acquisition module for synchronously triggering the thermal imaging modules to synchronously acquire infrared images of the asphalt pavement under the same time reference; an embedded processing unit for correcting the infrared images of the asphalt pavement synchronously acquired by the thermal imaging modules in geometry, performing infrared radiation consistency compensation, image registration, fusion and conversion, and generating temperature data covering the temperature distribution of the cross section of the asphalt pavement to be output.

2. The asphalt pavement temperature field scanner of claim 1, wherein, The temperature measurement range of the thermal imaging module is -20 DEG C to +500 DEG C.

3. The asphalt pavement temperature field scanner of claim 1, wherein, The spatial resolution of the thermal imaging module reaches the equivalent sampling density of 1-10 cm / pixel.

4. The asphalt pavement temperature field scanner of claim 1, wherein, The overlapping proportion of the field of view projected by the adjacent thermal imaging modules on the asphalt pavement is 10%-30%.

5. The asphalt pavement temperature field scanner of claim 1, wherein, The acquisition frame rate of the thermal imaging module is 1-50 Hz.

6. The asphalt pavement temperature field scanner of claim 1, wherein, The image registration is completed by using the feature point matching, phase correlation method or template matching.

7. The asphalt pavement temperature field scanner of claim 1, wherein, The temperature data are one-dimensional temperature data or two-dimensional temperature images.

8. The asphalt pavement temperature field scanner of claim 6, wherein, The format of the temperature data is CSV, binary array or compressed thermal image.

9. The asphalt pavement temperature field scanner of claim 1, wherein, The application further comprises a protective shell, the thermal imaging modules are installed on the protective shell, and the synchronous acquisition module and the embedded processing unit are installed in the protective shell.

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