Melting monitoring method based on asphalt pavement temperature analysis

Abstract

The invention relates to the technical field of temperature monitoring, and particularly discloses a melting monitoring method based on asphalt pavement temperature analysis, which comprises the following steps: establishing a standard curve in a standard experiment scene; drawing a real-time curve when the position A is shielded by a shadow in the ith monitoring period; generating coordinate points based on the real-time curve and the standard curve, and fitting the coordinate points to obtain a compensation curve; setting a plurality of supplementary points, selecting a target point according to the condition that the supplementary points are shielded by the shadow, and calculating the compensation amount according to the temperature change condition of the target point in combination with the compensation curve; and obtaining the temperature of the asphalt pavement monitored by the infrared device, subtracting the compensation amount from the temperature to obtain a standard temperature, and judging whether the asphalt pavement has a melting risk or not according to the standard temperature. According to the invention, the accuracy of asphalt pavement melting monitoring is improved.

Description

Technical Field

[0001] This invention relates to the field of temperature monitoring technology, and specifically to a melting monitoring method based on asphalt pavement temperature analysis. Background Technology

[0002] Asphalt pavement melting does not mean complete liquefaction, but rather the softening and decreased adhesion of asphalt materials under high temperatures, leading to pavement performance failure. The core cause is the combination of high ambient temperatures (road surface temperatures often exceed 60°C at midday in summer) and heat generated by vehicle friction, causing the asphalt to exceed its softening threshold. Initially, melting manifests as oil seepage and slight indentations at wheel tracks; later, it develops into obvious ruts, shoving, and even asphalt sticking to tires. This not only affects driving stability but also increases braking distance due to reduced road surface skid resistance, directly threatening traffic safety.

[0003] Rural roads are prone to dust and gravel buildup due to infrequent routine maintenance. This common situation directly interferes with road surface temperature monitoring that relies on infrared technology. Dust and asphalt have different physical properties; dust typically has a lower specific heat capacity than asphalt. Under the same sunlight exposure, the dust layer absorbs heat, and its temperature rises faster and at a higher peak than the underlying asphalt pavement. Therefore, infrared thermometers often read the temperature of the warmer dust layer covering the road surface, rather than the actual temperature of the asphalt itself. This can cause the monitoring system to record significantly higher abnormal data, potentially leading to an incorrect assessment that the road surface is "overheated," thus affecting the accuracy of high-temperature risk warnings. Summary of the Invention

[0004] The purpose of this invention is to provide a melting monitoring method based on asphalt pavement temperature analysis, thereby solving the above-mentioned technical problems.

[0005] The objective of this invention can be achieved through the following technical solutions: A melting monitoring method based on asphalt pavement temperature analysis includes the following steps: Establish a standard experimental scenario, and in the standard experimental scenario, establish a curve of temperature change of asphalt pavement over time, denoted as the standard curve; Based on a preset time window and sliding step size T, several monitoring cycles are set. In the i-th monitoring cycle, the location A of the monitoring point is obtained. When location A is occluded by a shadow, the temperature at location A is obtained based on the infrared device, and the curve of temperature change over time is plotted and recorded as the real-time curve. Coordinate points are generated based on the real-time curve and the standard curve. A compensation curve is obtained by fitting these coordinate points over the time period [ti]. end ti end Within +T], the compensation curve is used to compensate for the influence of dust on the temperature of asphalt pavement monitored by infrared devices. endThis indicates the end point of the i-th monitoring period; With position A as the center, set a circular area with a preset radius. Set several supplementary points at preset intervals within the circular area. Select the target point based on the situation where the supplementary points are occluded by shadows. Calculate the compensation amount based on the temperature change of the target point and the compensation curve. The temperature of the asphalt pavement is obtained from the infrared device, and the compensation amount is subtracted to obtain the standard temperature. The standard temperature is then used to determine whether there is a risk of melting of the asphalt pavement.

[0006] As a further aspect of the present invention: establishing a standard curve includes: In the standard scenario, within a preset sub-cycle, the temperature of the asphalt pavement is acquired in real time using an infrared device, and a standard curve is plotted.

[0007] As a further aspect of the present invention: the process of obtaining the fitted curve includes: Obtain the portion of the real-time curve that belongs to the sub-period, and denote it as the target curve; Starting from the starting point of the target curve, select several reference points on the target curve at preset time intervals, and obtain the absolute value of the tangent slope of the reference points; Obtain the temperature corresponding to the reference point on the target curve, denoted as the first temperature, and obtain the time interval J1 between the reference point and the starting point of the sub-cycle. On the standard curve, the temperature corresponding to the point with the horizontal axis of J1 is denoted as the second temperature. Subtract the corresponding second temperature from the first temperature to obtain the temperature difference. Use the absolute value of the slope of the tangent at the reference point as the x-axis and the corresponding temperature difference as the y-axis to generate coordinate points. Fit the coordinate points to obtain the compensation curve.

[0008] As a further aspect of the present invention: the calculation of the compensation amount includes: Determine the time period [ti] end ti end Within the sub-period B of +T], the first supplementary point occluded by the shadow within sub-period B is taken as the target point; Starting from the point when the target point is obscured by a shadow, the temperature of the target point is continuously acquired at n time points based on the infrared device, where n is a preset number; Sort the temperatures of the target points at n time points according to the time axis, calculate the average temperature change rate based on the sorting, and obtain the absolute value C of the average temperature change rate. Substitute the absolute value C into the compensation curve to obtain the compensation amount.

[0009] As a further aspect of the present invention: calculating the average temperature change rate includes: The average temperature change rate can be obtained by taking the difference between the last and first temperatures in the sorted data and dividing the difference by n.

[0010] As a further aspect of the present invention: during the time period [ti] end ti end Within [+T], new coordinate points are obtained, and a new compensation curve is generated using all coordinate points from the (i+1)th monitoring period. This new compensation curve compensates for the impact of dust on the temperature of asphalt pavement monitored by the infrared device. The applicable time period for this new compensation curve is [ti+1]. end ti+1 end +T],ti+1 end This marks the end point of the (i+1)th monitoring cycle.

[0011] As a further aspect of the present invention: if the standard temperature is higher than a preset temperature threshold, the corresponding time is marked as an abnormal time; if the time period [ti] end ti end If the total number of abnormal moments within [+T] exceeds a preset total number threshold, it is determined that the asphalt pavement is at risk of melting. The beneficial effects of this invention compared to the prior art are as follows: This invention establishes a standard temperature change pattern under conditions of no shadows and no dust, and combines this with the real-time changes in road surface temperature over time to dynamically compensate for infrared thermometry results, making the monitoring results closer to the true temperature of the asphalt pavement. This method effectively corrects the problem of inflated infrared thermometry caused by dust layers, reduces the impact of environmental factors on temperature monitoring accuracy, and thus improves the reliability and stability of pavement melting risk assessment. By introducing a self-learning update mechanism for the relationship between temperature change rate and compensation during the monitoring process, this invention can adapt to different dust coverage conditions and climatic conditions, achieving long-term stable temperature monitoring and intelligent compensation. Overall, this method improves the accuracy and practicality of infrared thermometry-based pavement temperature monitoring systems in complex environments. Attached Figure Description

[0012] The invention will now be further described with reference to the accompanying drawings.

[0013] Figure 1 This is a schematic flowchart of a melting monitoring method based on asphalt pavement temperature analysis according to the present invention. Detailed Implementation

[0014] 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.

[0015] Please see Figure 1As shown, this invention is a melting monitoring method based on asphalt pavement temperature analysis, comprising the following steps: Establish a standard experimental scenario, and in the standard experimental scenario, establish a curve of temperature change of asphalt pavement over time, denoted as the standard curve; It should be noted that the standard test scenario ensures that the asphalt road surface is free from shadows and dust. In a preferred embodiment of the present invention, establishing a standard curve includes: In the standard scenario, within a preset sub-cycle, the temperature of the asphalt pavement is acquired in real time using an infrared device, and a standard curve is plotted.

[0016] Based on a preset time window and sliding step size T, several monitoring cycles are set. In the i-th monitoring cycle, the location A of the monitoring point is obtained. When location A is occluded by a shadow, the temperature at location A is obtained based on the infrared device, and the curve of temperature change over time is plotted and recorded as the real-time curve. It is important to note that the time window is used to determine the range of data continuity upon which the compensation curve generation depends, and the sliding step size is used to control the time progression between adjacent monitoring periods. The preferred time window is three days, meaning that the data range of each monitoring period covers the temperature change process over three consecutive days. The preferred sliding step size T is one day, meaning that each day, the monitoring period slides forward by one day, and the new monitoring period includes data from the last two days of the previous period and the data from the newly added day, thus achieving a smooth transition in time. This ensures that the update of the compensation curve reflects the latest environmental conditions while maintaining data continuity.

[0017] The monitoring period is divided using a fixed-length sliding window structure, forming a continuous observation sequence on the time axis. This setting ensures that each period has sufficient data for curve fitting and avoids amplification of deviations caused by abnormal environmental conditions or data interruptions on a single day.

[0018] Location A is typically selected based on a representative area of ​​the road, preferably in a section with a smooth, unobstructed asphalt surface and minimal traffic interference. The infrared device continuously records surface temperature changes at this location. When location A experiences shadow coverage during a certain time of day, it indicates a temporary reduction in incident irradiance; the temperature response at this time reflects the changing characteristics of surface thermal inertia. The infrared device activates a high-frequency sampling mode at the moment shadow appears, acquiring surface temperature change data at short time intervals to ensure the complete recording of the temperature drop process. The sampled data, after being timestamped, is compiled into a continuous curve of temperature change over time; this curve is the real-time curve. The real-time curve contains transient thermal response information of the dust layer when light intensity changes, revealing differences in surface temperature response caused by dust coverage compared to temperature change curves under standard scenarios. By compiling and analyzing the real-time curves of multiple shadow events within different monitoring periods, the compensation relationship can be continuously updated, ensuring that the infrared temperature measurement data remains consistent with the actual asphalt temperature during long-term monitoring.

[0019] Coordinate points are generated based on the real-time curve and the standard curve. A compensation curve is obtained by fitting these coordinate points over the time period [ti]. end ti end Within +T], the compensation curve is used to compensate for the influence of dust on the temperature of asphalt pavement monitored by infrared devices. end This indicates the end point of the i-th monitoring period; In another preferred embodiment of the present invention, the process of obtaining the compensation curve includes: Obtain the portion of the real-time curve that belongs to the sub-period, and denote it as the target curve; Starting from the starting point of the target curve, select several reference points on the target curve at preset time intervals, and obtain the absolute value of the tangent slope of the reference points; Obtain the temperature corresponding to the reference point on the target curve, denoted as the first temperature, and obtain the time interval J1 between the reference point and the starting point of the sub-cycle. On the standard curve, the temperature corresponding to the point with the horizontal axis of J1 is denoted as the second temperature. Subtract the corresponding second temperature from the first temperature to obtain the temperature difference. Use the absolute value of the slope of the tangent at the reference point as the x-axis and the corresponding temperature difference as the y-axis to generate coordinate points. Fit the coordinate points to obtain the compensation curve.

[0020] It should be noted that by acquiring the portion of the real-time curve within a sub-period and selecting several reference points, the trend of surface temperature change over a certain period can be obtained. The absolute value of the tangent slope at the reference point reflects the rate of temperature change, i.e., the surface's response speed to irradiation changes. Due to the different thermal inertia of the dust layer and the asphalt layer, the dust layer has a lower specific heat capacity and lower thermal conductivity. When subjected to irradiation energy, it requires less heat per unit mass, resulting in a faster temperature rise. When irradiation weakens, the stored heat is more easily dissipated, leading to a faster temperature drop. The rapid temperature response of the dust layer causes the surface temperature measured by the infrared device to be higher than the actual temperature of the underlying asphalt layer, creating a false high temperature. By comparing the temperature difference at the reference point with the corresponding time in the standard curve, the infrared reading deviation caused by the thermal response characteristics of the dust can be obtained. Establishing a correspondence between these deviations and the corresponding temperature change rates and fitting the curve, the resulting compensation curve reflects the functional relationship between the temperature change rate and the infrared false high temperature. This connection stems from the combined effects of thermal conduction and energy balance: when the dust layer heats up, the absorbed radiant energy is mainly concentrated on the surface, with slow downward conduction, causing its surface temperature to rise rapidly in a short time; when irradiation weakens, the temperature difference between the surface and the environment increases, the heat dissipation rate rises, and the temperature drops rapidly. Regardless of whether irradiation increases or decreases, the thermal response of the dust layer is faster than that of the asphalt layer. This two-way difference in temperature response reflects the same thermal inertia law. The compensation curve is an empirical mapping based on this difference in thermal inertia. Therefore, in subsequent temperature measurements, regardless of whether the temperature is rising or falling, the artificial height caused by dust can be determined by analyzing the real-time temperature change rate and used to correct the infrared thermometry results.

[0021] It is worth noting that the compensation curve does not simply describe the behavior of "cooling in the shade"; it essentially describes the relationship between the surface temperature response rate to changes in irradiance and the difference in thermal inertia of the dust.

[0022] In other words, the rule it expresses is: the thinner and looser the surface layer (the more dust), the faster the thermal response (whether it is heating up or cooling down), and the greater the falsely high infrared reading.

[0023] The shadow is merely a convenient and controllable trigger for us to observe this response in the "cooling direction," allowing us to clearly measure the "speed of thermal response." Therefore, although the empirical curve is learned from shadow events, it reflects a two-way physical property: the thermal inertia characteristics of the dust layer.

[0024] With position A as the center, set a circular area with a preset radius. Set several supplementary points at preset intervals within the circular area. Select the target point based on the situation where the supplementary points are occluded by shadows. Calculate the compensation amount based on the temperature change of the target point and the compensation curve. In another preferred embodiment of the present invention, the calculation of the compensation amount includes: Determine the time period [ti] end ti end Within the sub-period B of +T], the first supplementary point occluded by the shadow within sub-period B is taken as the target point; Starting from the point when the target point is obscured by a shadow, the temperature of the target point is continuously acquired at n time points based on the infrared device, where n is a preset number; Sort the temperatures of the target points at n time points according to the time axis, calculate the average temperature change rate based on the sorting, and obtain the absolute value C of the average temperature change rate. Substitute the absolute value C into the compensation curve to obtain the compensation amount.

[0025] It is worth noting that during the monitoring process, since location A may be continuously exposed to direct sunlight without being shaded during certain periods, data for updating the compensation curve cannot be obtained. Therefore, a circular area centered on location A is set up with several supplementary points to introduce alternative observation objects spatially. When a supplementary point is shaded, its temperature change process has similar thermal environment and dust coverage characteristics to location A, maintaining consistency in heat conduction and irradiance response (due to the close proximity, the dust situation is not significantly different). By selecting the first shaded supplementary point as the target point within a sub-cycle and continuously recording its temperature change, the rate of surface temperature decrease can be captured as the shadow passes. This rate is then substituted into the compensation curve to calculate the compensation amount, allowing the compensation process to be carried out daily without interruption. The circular area ensures that spatial differences are controllable, avoiding errors caused by differences in dust distribution or irradiance conditions. The compensation obtained in this way can reflect the actual thermal response characteristics of the road surface dust layer on that day, providing a basis for correcting infrared temperature measurement deviations, thereby maintaining the continuity and stability of the temperature correction process, and ensuring that the monitoring results can still accurately reflect the true temperature of the asphalt layer under different lighting and shading conditions.

[0026] It is important to note that calculating the average rate of temperature change includes: The average temperature change rate can be obtained by taking the difference between the last and first temperatures in the sorted data and dividing the difference by n.

[0027] In another preferred embodiment of the present invention, during the time period [ti] end ti end Within [+T], new coordinate points are obtained, and a new compensation curve is generated using all coordinate points from the (i+1)th monitoring period. This new compensation curve compensates for the impact of dust on the temperature of asphalt pavement monitored by the infrared device. The applicable time period for this new compensation curve is [ti+1]. end ti+1 end +T],ti+1 end This marks the end point of the (i+1)th monitoring cycle.

[0028] During continuous monitoring, the thickness of dust, humidity, and lighting conditions on the road surface vary over time, causing the pattern of infrared thermometry error to become inconsistent. By acquiring new coordinate points within a new time period and regenerating the compensation curve, the compensation relationship can be made consistent with the actual environment at that time. The compensation curve reflects the correspondence between the rate of temperature change and the infrared thermometry deviation. This relationship is affected by the combined influence of dust thermal inertia, air humidity, and light intensity. If the same curve is used for correction over a long period, it will be difficult to reflect the current thermal response characteristics. The new compensation curve, after being updated, can incorporate the latest data from the most recent monitoring period, allowing the model to continuously fit the current road surface conditions, thereby ensuring the timeliness and accuracy of the compensation process.

[0029] The temperature of the asphalt pavement monitored by the infrared device is obtained, and the compensation amount is subtracted from it to obtain the standard temperature. The standard temperature is then used to determine whether the asphalt pavement is at risk of melting. It should be noted that if the standard temperature is higher than the preset temperature threshold, the corresponding time will be marked as an abnormal time. If the time period [ti] end ti end If the total number of abnormal moments within +T] exceeds the preset total number threshold, it is determined that the asphalt pavement is at risk of melting.

[0030] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A melting monitoring method based on asphalt pavement temperature analysis, characterized in that, Includes the following steps: Establish a standard experimental scenario, and in the standard experimental scenario, establish a curve of temperature change of asphalt pavement over time, denoted as the standard curve; Based on a preset time window and sliding step size T, several monitoring cycles are set. In the i-th monitoring cycle, the location A of the monitoring point is obtained. When location A is occluded by a shadow, the temperature at location A is obtained based on the infrared device, and the curve of temperature change over time is plotted and recorded as the real-time curve. Coordinate points are generated based on the real-time curve and the standard curve. A compensation curve is obtained by fitting these coordinate points over the time period [ti]. end ti end Within +T], the compensation curve is used to compensate for the influence of dust on the temperature of asphalt pavement monitored by infrared devices. end This indicates the end point of the i-th monitoring period; With position A as the center, set a circular area with a preset radius. Set several supplementary points at preset intervals within the circular area. Select the target point based on the situation where the supplementary points are occluded by shadows. Calculate the compensation amount based on the temperature change of the target point and the compensation curve. The temperature of the asphalt pavement is obtained from the infrared device, and the compensation amount is subtracted to obtain the standard temperature. The standard temperature is then used to determine whether there is a risk of melting of the asphalt pavement.

2. The melting monitoring method based on asphalt pavement temperature analysis according to claim 1, characterized in that, Establishing a standard curve includes: In the standard scenario, within a preset sub-cycle, the temperature of the asphalt pavement is acquired in real time using an infrared device, and a standard curve is plotted.

3. The melting monitoring method based on asphalt pavement temperature analysis according to claim 1, characterized in that, The process of obtaining the compensation curve includes: Obtain the portion of the real-time curve that belongs to the sub-period, and denote it as the target curve; Starting from the starting point of the target curve, select several reference points on the target curve at preset time intervals, and obtain the absolute value of the tangent slope of the reference points; Obtain the temperature corresponding to the reference point on the target curve, denoted as the first temperature, and obtain the time interval J1 between the reference point and the starting point of the sub-cycle. On the standard curve, the temperature corresponding to the point with the horizontal axis of J1 is denoted as the second temperature. Subtract the corresponding second temperature from the first temperature to obtain the temperature difference. Use the absolute value of the slope of the tangent at the reference point as the x-axis and the corresponding temperature difference as the y-axis to generate coordinate points. Fit the coordinate points to obtain the compensation curve.

4. The melting monitoring method based on asphalt pavement temperature analysis according to claim 1, characterized in that, The calculation of compensation includes: Determine the time period [ti] end ti end Within the sub-period B of +T], the first supplementary point occluded by the shadow within sub-period B is taken as the target point; Starting from the point when the target point is obscured by a shadow, the temperature of the target point is continuously acquired at n time points based on the infrared device, where n is a preset number; Sort the temperatures of the target points at n time points according to the time axis, calculate the average temperature change rate based on the sorting, and obtain the absolute value C of the average temperature change rate. Substitute the absolute value C into the compensation curve to obtain the compensation amount.

5. The melting monitoring method based on asphalt pavement temperature analysis according to claim 4, characterized in that, The calculation of the average rate of temperature change includes: The average temperature change rate can be obtained by taking the difference between the last and first temperatures in the sorted data and dividing the difference by n.

6. The melting monitoring method based on asphalt pavement temperature analysis according to claim 1, characterized in that, During the time period [ti end ti end Within [+T], new coordinate points are obtained, and a new compensation curve is generated using all coordinate points from the (i+1)th monitoring period. This new compensation curve compensates for the impact of dust on the temperature of asphalt pavement monitored by the infrared device. The applicable time period for this new compensation curve is [ti+1]. end ti+1 end +T],ti+1 end This marks the end point of the (i+1)th monitoring cycle.

7. The melting monitoring method based on asphalt pavement temperature analysis according to claim 1, characterized in that, If the standard temperature is higher than the preset temperature threshold, the corresponding time will be marked as an abnormal time. If the time period [ti] end ti end If the total number of abnormal moments within +T] exceeds the preset total number threshold, it is determined that the asphalt pavement is at risk of melting.

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