A method for controlling the material temperature during the transportation of asphalt concrete.

Abstract

This invention relates to the field of road engineering material construction technology, and in particular to a method for controlling the material temperature during the transportation of asphalt concrete. This invention achieves full-area temperature sensing of the asphalt pile through multi-source heterogeneous data acquisition and three-dimensional temperature field modeling, solving the problems of incomplete coverage and inability to characterize spatial distribution in traditional single-point temperature measurement. Simultaneously, based on multi-feature comparison and multi-dimensional zoning discrimination, it can accurately identify overheated zones, core high-temperature zones, secondary high-temperature transition zones, peripheral low-temperature zones, and abnormal cooling zones. Differentiated control is adopted for different zones to achieve refined temperature control, avoiding energy waste and temperature control conflicts caused by overall temperature control. Furthermore, by setting zone control priorities, it unifies and coordinates conflicting commands and triggers safety alarms. Based on the temperature change rate and remaining transportation time, it predicts the arrival temperature and combines it with power closed-loop compensation to achieve early intervention, ensuring that the asphalt mixture unloading temperature remains stable within the allowable construction range, thus guaranteeing paving and compaction quality.

Description

Technical Field

[0001] This invention relates to the field of road engineering material construction technology, and in particular to a method for controlling the material temperature during the transportation of asphalt concrete. Background Technology

[0002] As a core material in road engineering, the temperature stability of asphalt mixtures during transportation directly affects the paving and compaction quality and the service life of the road surface. In actual transportation, the asphalt material pile inside the truck bed is affected by factors such as ambient temperature, wind speed, transportation time, uneven heat dissipation at the boundaries of the truck bed, surface depressions or cracks, which can easily lead to local overheating, rapid cooling at the edges, uneven internal temperature distribution, and abnormal cooling. This can cause the unloading temperature to deviate from the construction specifications, resulting in insufficient road compaction, cracking, rutting and other defects.

[0003] Existing temperature control technologies for asphalt transportation mainly rely on single-point contact temperature measurement, overall insulation, and passive temperature control, which have obvious drawbacks: on the one hand, relying on only a small number of measuring points to collect temperature cannot reflect the three-dimensional temperature distribution inside the stockpile, and it is easy to miss local overheating and abnormal cooling areas; on the other hand, they do not perform intelligent zoning according to temperature status, and mostly adopt overall heating or ventilation, which results in crude temperature control, high energy consumption, and easy temperature control contradictions. Furthermore, there is no on-site temperature prediction and power closed-loop compensation mechanism, resulting in lagging temperature control response, low control accuracy, and inability to ensure that the unloading temperature is stable within the allowable range for construction.

[0004] In summary, existing technologies are insufficient to meet the temperature control requirements of full-area perception, precise zoning, dynamic coordination, and predictive compensation during the transportation of asphalt mixtures, thus hindering the improvement of road construction quality. Therefore, developing a material temperature control method for the transportation of asphalt concrete has become an urgent technical problem to be solved in the field of road engineering. Summary of the Invention

[0005] This invention addresses the shortcomings of existing temperature control methods for asphalt transportation, such as incomplete temperature measurement, unintelligent zoning, uncoordinated regulation, and inaccurate prediction. It provides a material temperature control method for the transportation process of asphalt concrete, which realizes multi-source data acquisition, three-dimensional temperature field reconstruction, temperature zone identification, differentiated temperature control, and closed-loop control of arrival temperature prediction, ensuring that the temperature of asphalt mixtures is qualified throughout the transportation process.

[0006] The objective of this invention can be achieved through the following technical solution: a method for controlling the material temperature during the transportation of asphalt concrete, comprising the following steps:

[0007] Step 1: Based on the multi-source heterogeneous data acquisition and preprocessing of asphalt transport vehicles, construct the T in the three-dimensional temperature field dynamic model of the stockpile;

[0008] Step 2: Construct the real-time feature dataset and establish association rules between temperature features and partition types, implement the division and writing of tag codes, and obtain the partition tag matrix L;

[0009] Step 3: Traverse the partition label matrix L, group adjacent grids with the same label code into the same connected component, and complete the subsequent connected component boundary smoothing process to output the final partition connected component graph;

[0010] Step 4: Based on the final partitioned connected domain graph, perform ventilation control in the overheated zone, heat preservation control in the secondary high temperature transition zone, heat replenishment calculation in the edge low temperature zone, and identification and heat replenishment triggering in the abnormal cooling zone according to the partition type. Process conflicting instructions according to preset priorities, generate a dynamic feedback control list, and realize closed-loop temperature control.

[0011] Step 5: Predict the arrival temperature without intervention based on the temperature change rate of each connected domain, calculate the target reference temperature and the required temperature change according to the overheating / overcooling state, determine the compensation power and the actual execution power, output the actuator parameters, iteratively correct, stop the new calculation when the remaining transportation time is less than the preset threshold and maintain the current command until unloading.

[0012] Preferably, the analysis process of T in the three-dimensional temperature field dynamic model of the stockpile is as follows:

[0013] Temperature data from all temperature measurement points are collected at a preset fixed frequency. At the same time, transportation speed, transportation time and transportation route information are acquired in real time to form multi-source heterogeneous data. The multi-source heterogeneous data is preprocessed to form a standardized multi-source heterogeneous data pool.

[0014] At the same time, with the front left corner of the carriage floor as the origin, a unified coordinate system for the carriage is established in the x-direction of carriage length, y-direction of width, and z-direction of height. The measurement points of each sensor are mapped to this coordinate system, and the carriage space is divided into uniform grids according to preset ΔX, ΔY and ΔZ.

[0015] Based on a standardized multi-source heterogeneous data pool, the discrete measurement point temperature is extended to the entire grid, and the initial maximum temperature, minimum temperature, average temperature and temperature standard deviation of each grid are obtained to construct a three-dimensional temperature field dynamic model T of the stockpile. At the same time, the temperature change rate of each grid is calculated, and the data of each grid is mapped to the three-dimensional temperature field dynamic model T of the stockpile.

[0016] Preferably, the analysis process of the partition label matrix L is as follows:

[0017] Based on the real-time three-dimensional temperature field dynamic model T of the stockpile, for each grid, the current temperature value T, the distance d from the nearest car wall, the thermal gradient amplitude, and the temperature change rate are read to construct a real-time feature dataset;

[0018] Set a temperature threshold benchmark for each zone and establish rules for the association between temperature characteristics and zone type;

[0019] Based on the real-world feature dataset, the labels are written into the dynamic model T of the three-dimensional temperature field of the material pile according to the association rules between temperature features and zoning types, resulting in the zoning label matrix L. For the grid located on the surface of the material pile, an additional criterion is added: if the temperature value is less than the lower limit temperature of paving TL - preset critical value and the defect type is identified as depression or crack through surface feature image, then the corresponding grid is forcibly marked as an abnormal cooling zone.

[0020] Preferably, the association rule between the temperature feature and the partition type is as follows:

[0021] If the temperature value is greater than or equal to the upper limit of the allowable paving temperature TH, it is determined to be an overheated zone and marked as 0. If the lower limit of the allowable paving temperature TL is less than or equal to the temperature value but less than the upper limit of the allowable paving temperature TH, and the distance from the boundary d is greater than the preset distance threshold, it is determined to be a core high-temperature zone and marked as 1. If the lower limit of the allowable paving temperature TL is less than or equal to the temperature value but less than the upper limit of the allowable paving temperature TH, and the distance from the boundary d is less than the preset distance threshold, it is determined to be a secondary high-temperature transition zone and marked as 2. If the temperature value is less than or equal to the lower limit of the allowable paving temperature TL, and the thermal gradient amplitude is less than the preset thermal gradient amplitude, it is determined to be an edge low-temperature zone and marked as 3. If the temperature value is less than or equal to the lower limit of the allowable paving temperature TL, and the thermal gradient amplitude is greater than or equal to the preset thermal gradient amplitude or the temperature change rate is less than the preset temperature change rate, it is determined to be an abnormal cooling zone and marked as 4.

[0022] Preferably, the analysis process of the final partitioned connected component graph is as follows:

[0023] Traverse the partition label matrix L, group adjacent grids with the same label code into the same connected component, and assign a unique ID to each connected component;

[0024] Set a minimum partition volume threshold Vmin, perform merging processing on isolated partitions whose volume is smaller than the minimum partition volume threshold Vmin, and smooth the boundaries of each partition to output the final partition connected component graph.

[0025] Preferably, the generation and analysis process of the dynamic feedback control list is as follows:

[0026] Based on the final partitioned connected domain graph, the average temperature and overheating amount ΔC of the overheated zone connected domain with a marker code of 0 are obtained, and the ventilation opening of the adjustable vent located above the overheated zone connected domain is controlled.

[0027] Extract all connected components of the sub-high temperature transition zone with a marker code of 2 to predict the temperature YT when it reaches the unloading port. Based on the judgment, trigger the enhanced insulation command and / or trigger the weakened insulation command.

[0028] Extract the temperature deficit ΔK of each region corresponding to the connected domain of the edge low temperature zone marked with code 3, and then obtain the required heat replenishment of each edge low temperature zone connected domain. Extract the temperature change rate of the connected domain of the abnormal cooling zone marked with code 4. If the temperature change rate of a certain abnormal cooling zone connected domain is greater than the preset proportional coefficient × the average temperature change rate of the material pile, it is determined to be a local abnormality and a heat replenishment command is triggered.

[0029] Obtain the set priority of each connected domain. When conflicting instructions are received in the same connected domain or adjacent areas, the instruction with higher priority is executed first, and a safety alarm instruction is triggered.

[0030] A dynamic feedback control list is constructed based on ventilation opening, enhanced insulation command and / or weakened insulation command, required heat replenishment Qn, and triggered heat replenishment command.

[0031] Preferably, step five includes:

[0032] S1: Obtain the estimated remaining transportation time and target arrival temperature window of the asphalt transport vehicle, mark each connected component as i, where i is a natural number greater than zero, and obtain the temperature change rate vi of the two most recent preset fixed frequencies for each connected component;

[0033] S2: Predict the temperature TXI of each connected domain when it reaches the unloading point under non-intervention conditions;

[0034] S3: For each connected component, compare the temperature TXI with the target arrival temperature window, and output whether it is overheated, undercooled, or uncompensated.

[0035] S4: Obtain the target reference temperature MTi corresponding to overheating or overcooling;

[0036] S5: Obtain the required temperature change STi when overheating or overcooling occurs;

[0037] S6: Based on the required temperature change STi when overheating or overcooling, obtain the required compensation power Pi, and according to the type of connected domain in each partition, obtain the maximum power of the actuator in each connected domain.

[0038] Preferably, it also includes S7: then obtaining the actual execution power SZi of the current actuator in each partition connectivity domain;

[0039] If the required compensation power Pi is greater than the maximum power of the actuator, an insufficient power alarm is triggered and the insufficient power alarm log is recorded.

[0040] Retrieve the preset power-command mapping table, output the actuator parameters based on the actual execution power SZi, and wait for execution. The actuator parameters include ventilation opening and heating duty cycle.

[0041] S8: Every preset fixed frequency, repeat steps S1-S7 above. Each time the calculation is repeated, the prediction will be corrected based on the latest measured temperature and the updated remaining time. If the expected remaining transportation time is less than the preset time threshold, stop the new compensation calculation and keep the current instruction until unloading.

[0042] The beneficial effects of this invention are as follows:

[0043] (1) This invention achieves full-domain temperature sensing of asphalt piles through multi-source heterogeneous data acquisition and three-dimensional temperature field modeling, solving the problems of incomplete coverage and spatial distribution of traditional single-point temperature measurement. At the same time, it performs multi-dimensional partitioning based on temperature, boundary distance, thermal gradient, temperature change rate and surface defects, which can accurately identify overheated areas, core high-temperature areas, secondary high-temperature transition areas, edge low-temperature areas and abnormal cooling areas. Differentiated control is adopted for different partitions to achieve refined temperature control, avoid energy waste and temperature control contradictions caused by overall temperature control, and significantly improve the control efficiency.

[0044] (2) By setting the priority of zone control, coordinating conflicting instructions and triggering safety alarms, this invention effectively avoids temperature control failure caused by temperature control logic conflicts, and predicts the arrival temperature based on the temperature change rate and remaining transportation time, combined with power closed-loop compensation to achieve early intervention, ensuring that the unloading temperature of asphalt mixture is stable within the construction allowable range, and guaranteeing the paving and compaction quality. Attached Figure Description

[0045] The invention will now be further described with reference to the accompanying drawings;

[0046] Figure 1 This is a reference analysis diagram of the method of the present invention;

[0047] Figure 2 This is a reference diagram for constructing T in the three-dimensional temperature field dynamic model of the stockpile;

[0048] Figure 3 This is a schematic diagram for analysis in step five of the present invention. Detailed Implementation

[0049] 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.

[0050] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments;

[0051] Example 1:

[0052] Please see Figures 1 to 3 As shown, this invention provides a method for controlling the material temperature during the transportation of asphalt concrete, comprising the following steps:

[0053] Step 1: Based on the multi-source heterogeneous data acquisition and preprocessing of asphalt transport vehicles, construct the T in the three-dimensional temperature field dynamic model of the stockpile;

[0054] Step 2: Construct the real-time feature dataset and establish association rules between temperature features and partition types, implement the division and writing of tag codes, and obtain the partition tag matrix L;

[0055] Step 3: Traverse the partition label matrix L, group adjacent grids with the same label code into the same connected component, and complete the subsequent connected component boundary smoothing process to output the final partition connected component graph;

[0056] Step 4: Based on the final partitioned connected domain graph, perform ventilation control in the overheated zone, heat preservation control in the secondary high temperature transition zone, heat replenishment calculation in the edge low temperature zone, and identification and heat replenishment triggering in the abnormal cooling zone according to the partition type. Process conflicting instructions according to preset priorities, generate a dynamic feedback control list, and realize closed-loop temperature control.

[0057] Step 5: Predict the arrival temperature without intervention based on the temperature change rate of each connected domain, calculate the target reference temperature and the required temperature change according to the overheating / overcooling state, determine the compensation power and the actual execution power, output the actuator parameters, iteratively correct, stop the new calculation when the remaining transportation time is less than the preset threshold and maintain the current instruction until unloading;

[0058] Step one: Based on the multi-source heterogeneous data acquisition and preprocessing of asphalt transport vehicles, construct the three-dimensional temperature field dynamic model T of the stockpile, specifically including:

[0059] Inside the asphalt transport truck, data sensing devices such as contact thermocouples, infrared array sensors, and wireless temperature probes are installed on the truck wall according to the preset installation drawings. Temperature data of all temperature measurement points are collected at a preset fixed frequency. At the same time, information such as transport speed, transport time, and transport route information are acquired in real time to form multi-source heterogeneous data.

[0060] Multi-source heterogeneous data is preprocessed, including cleaning and spatiotemporal alignment, to form a standardized multi-source heterogeneous data pool.

[0061] At the same time, taking the front left corner of the carriage floor as the origin, a unified coordinate system for the carriage is established with x in the direction of carriage length (0-L), y in the direction of width (0-W), and z in the direction of height (0-H), and the measurement points of each sensor are mapped to this coordinate system;

[0062] The carriage space is divided into uniform grids according to preset ΔX, ΔY and ΔZ, where ΔX, ΔY and ΔZ are all greater than zero, such as: ΔX = 5cm, ΔY = 5cm and ΔZ = 5cm. The total number of grids is approximately (L / 0.05) × (W / 0.05) × (H / 0.05).

[0063] Based on a standardized multi-source heterogeneous data pool, a pre-defined Kriging interpolation method is used to extend the discrete measurement point temperature to the entire grid, obtain the initial maximum temperature, minimum temperature, average temperature and temperature standard deviation of each grid, and construct a three-dimensional temperature field dynamic model T(x, y, z, t) of the stockpile, where t (t>0) represents time. At the same time, the temperature change rate of each grid is calculated, and the data of each grid (including the initial maximum temperature, minimum temperature, average temperature, temperature standard deviation, etc.) are mapped to T in the three-dimensional temperature field dynamic model of the stockpile.

[0064] Example 2:

[0065] Step Two: Constructing the Real-Time Feature Dataset and Establishing Association Rules Between Temperature Features and Partition Types, Implementing Tag Code Division and Writing, and Obtaining the Partition Label Matrix L. Specific contents include:

[0066] Based on the real-time three-dimensional temperature field dynamic model T(x, y, z, t) of the stockpile, information such as the current temperature value T, the distance d from the nearest car wall, the thermal gradient magnitude, and the temperature change rate are read for each grid to construct a real-time feature dataset.

[0067] Based on the construction temperature standard of asphalt mixture (such as AC type asphalt mixture with a factory temperature of 150-165℃ and a transportation temperature of ≥140℃), set the temperature threshold benchmark for each zone and establish the correlation rule between temperature characteristics and zone type.

[0068] The zoning temperature threshold benchmarks include: the lower limit temperature allowed for paving TL, the upper limit temperature allowed for paving TH, and preset distance thresholds, etc.

[0069] Among them, the target paving temperature value TB and the maximum allowable temperature drop ΔT are obtained, and the lower allowable paving temperature TL and the upper allowable paving temperature TH are calculated based on the target paving temperature value TB and the maximum allowable temperature drop ΔT.

[0070] Wherein, the lower limit of the allowable paving temperature TL = target paving temperature value TB - maximum allowable temperature drop ΔT;

[0071] The maximum allowable paving temperature TH = target paving temperature TB + maximum allowable temperature drop ΔT;

[0072] Association rules between temperature characteristics and partition type:

[0073] If the temperature value is greater than or equal to the upper limit of the allowable paving temperature TH, it is determined to be an overheated zone and marked as 0. If the lower limit of the allowable paving temperature TL is less than or equal to the temperature value but less than the upper limit of the allowable paving temperature TH, and the distance from the boundary d is greater than the preset distance threshold, it is determined to be a core high-temperature zone and marked as 1. If the lower limit of the allowable paving temperature TL is less than or equal to the temperature value but less than the upper limit of the allowable paving temperature TH, and the distance from the boundary d is less than the preset distance threshold, it is determined to be a secondary high-temperature transition zone and marked as 2. If the temperature value is less than or equal to the lower limit of the allowable paving temperature TL, and the thermal gradient amplitude is less than the preset thermal gradient amplitude, it is determined to be an edge low-temperature zone and marked as 3. If the temperature value is less than or equal to the lower limit of the allowable paving temperature TL, and the thermal gradient amplitude is greater than or equal to the preset thermal gradient amplitude or the temperature change rate is less than the preset temperature change rate, it is determined to be an abnormal cooling zone and marked as 4.

[0074] Based on the real-world feature dataset, the labels are written into the dynamic model T of the three-dimensional temperature field of the material pile according to the association rules between temperature features and zoning type, resulting in the zoning label matrix L. For the grid located on the surface of the material pile (the upper surface is exposed under the insulation blanket), an additional criterion is added: if the temperature value is less than the lower limit temperature of paving TL - preset critical value and the defect type is identified as depression or crack through surface feature image, then the corresponding grid is forcibly marked as an abnormal cooling zone.

[0075] The process involves inputting the collected surface feature images of the material pile into a preset material pile defect recognition model, and outputting the surface defect type of the material pile (such as dents, cracks, etc.).

[0076] Step 3: Traverse the partition label matrix L, group adjacent grids with the same label code into the same connected component, and perform subsequent connected component boundary smoothing processing to output the final partition connected component graph. Specific content includes:

[0077] Traverse the partition label matrix L, group adjacent grids with the same label code into the same connected component, assign a unique ID to each connected component, and record its boundary grid, centroid coordinates and other information.

[0078] Set a minimum partition volume threshold Vmin, and perform merging processing on isolated partitions with volumes smaller than the minimum partition volume threshold Vmin: if the isolated partition is an overheated zone or a core high-temperature zone, merge it into the adjacent partition with the largest volume; if the isolated partition is an edge low-temperature zone or an abnormal cooling zone, merge it into the adjacent partition with the closest temperature; if the isolated partition is adjacent to multiple partitions with different labels, merge it into the partition with the largest boundary contact area.

[0079] The boundaries of each partition are smoothed by using a set three-dimensional median filter (e.g., a 3×3×3 window). Specifically, the marker codes of all grids within the window are taken, and the marker code of the center point is replaced with the statistical mode within the window. This process is repeated twice to eliminate jagged boundaries and output the final connected component graph of the partition.

[0080] Example 3:

[0081] Step 4: Based on the final connected domain graph of the partitions, perform ventilation control in the overheated zone, insulation control in the sub-high temperature transition zone, heat replenishment calculation in the edge low temperature zone, and identification and heat replenishment triggering in the abnormal cooling zone according to the partition type. Handle conflicting commands according to preset priorities, generate a dynamic feedback control list, and realize closed-loop temperature control. Specific content includes:

[0082] Based on the final partitioned connected domain graph, obtain the average temperature and overheat amount ΔC of the overheated zone connected domain with the marker code 0. Overheat amount ΔC = average temperature - paving allowable upper limit temperature TH.

[0083] Control the ventilation opening of the adjustable vent located above the overheated zone connection area. Ventilation opening = min (100%, preset percentage × overheat amount ΔC / 1℃). The ventilation direction is set to horizontal or diagonally downward to avoid disturbing the qualified secondary high temperature transition zone connection area.

[0084] Extract the temperature YT of all connected regions in the secondary high temperature transition zone with the mark code 2 when it reaches the unloading port. If the temperature YT of a certain secondary high temperature transition zone is less than the lower limit temperature T of paving + preset temperature range, then trigger the enhanced insulation command. If the temperature YT of a certain secondary high temperature transition zone is greater than the upper limit temperature TH of paving, then trigger the weakened insulation command.

[0085] Extract the temperature deficit ΔK for each region corresponding to all edge low temperature zone connected domains marked with code 3. Temperature deficit ΔK = paving allowable lower limit temperature TL - average temperature of edge low temperature zone connected domain (take positive value). Then obtain the required heat replenishment for each edge low temperature zone connected domain. Required heat replenishment Qn = specific heat capacity of asphalt concrete × mass of connected domain × temperature deficit ΔK.

[0086] Extract the temperature change rate of all connected regions in the abnormal cooling zone marked with code 4, compare the temperature change rate of the connected regions in the abnormal cooling zone with the average temperature change rate of the material pile, and if the temperature change rate of a connected region in the abnormal cooling zone is greater than the preset proportional coefficient × the average temperature change rate of the material pile, it is determined to be a local abnormality and a reheating command is triggered.

[0087] Obtain the set priority of each connected domain. Set the priority as follows: abnormal cooling zone > overheating zone > edge low temperature zone > second high temperature zone. When conflicting instructions are received in the same connected domain or adjacent areas (such as simultaneous requirements for ventilation and heating), the instruction with higher priority is executed first, and a safety alarm instruction is triggered to prompt the operator to intervene manually.

[0088] A dynamic feedback control list is constructed based on ventilation opening, enhanced insulation command and / or weakened insulation command, required heat replenishment Qn, and triggered heat replenishment command. At the same time, a dynamic feedback control list is generated at a preset fixed frequency to achieve dynamic closed-loop control. The operator controls the corresponding temperature control equipment (such as ventilation openings, PCM heat dissipation, etc.) in each connected area to work based on the output dynamic feedback control list, so as to achieve temperature control of each connected area.

[0089] Example 4:

[0090] Step 5: Predict the arrival temperature without intervention based on the temperature change rate of each connected domain. Calculate the target reference temperature and required temperature change based on the overheating / overcooling state, determine the compensation power and actual execution power, output the actuator parameters, iteratively correct, and stop new calculations when the remaining transportation time is less than a preset threshold, maintaining the current command until unloading. Specific steps include:

[0091] S1: Obtain the estimated remaining transportation time and target arrival temperature window of the asphalt transport vehicle. Target arrival temperature window: [lower allowable paving temperature TL, upper allowable paving temperature TH]. Mark each connected component as i, where i is a natural number greater than zero. Obtain the temperature change rate vi of the two most recent preset fixed frequencies for each connected component. If the temperature change rate vi > 0, it is determined that the temperature is rising. If the temperature change rate vi < 0, it is determined that the temperature is falling.

[0092] S2: Predict the temperature TXI of each connected domain when it reaches the unloading point under non-intervention conditions. Temperature TXI = Ti + temperature change rate vi × estimated remaining transportation time;

[0093] S3: For each connected domain, compare the temperature TXI with the target arrival temperature window. If the temperature TXI > the upper limit temperature allowed for paving TH + preset hysteresis band (e.g., 1℃, to avoid frequent operation), it is determined to be overheated. If the temperature TXI < the lower limit temperature allowed for paving TL - preset hysteresis band, it is determined to be undercooled. If the temperature TXI ∈ the target arrival temperature window, no compensation is given.

[0094] S4: Obtain the target reference temperature MTi corresponding to overheating or undercooling. The target reference temperature MTi for overheating is equal to the upper limit of the allowable paving temperature TH minus the preset safety margin, such as 1℃. The target reference temperature MTi for undercooling is equal to the lower limit of the allowable paving temperature TL plus the preset safety margin.

[0095] S5: Obtain the required temperature change STi when overheating or overcooling occurs. The required temperature change STi for overheating is equal to the target reference temperature MTi minus the temperature TXI. The required temperature change STi for overcooling is equal to the target reference temperature MTi minus the temperature TXI.

[0096] When it is overheated, STi < 0 (cooling is required); when it is undercooled, STi > 0 (heating is required).

[0097] S6: Based on the required temperature change STi during overheating or overcooling, obtain the required compensation power Pi (assuming uniform application throughout the process). Required compensation power Pi = (mi × c × |STi|) / estimated remaining transportation time.

[0098] Based on the type of the connected domain, obtain the maximum power of the actuator in each connected domain: Overheated connected domain: maximum heat dissipation power Psmax (ventilation and heat dissipation), edge low temperature connected domain: maximum heat release power PFmax (PCM phase change heat release), abnormal cooling connected domain: maximum heating power PJmax (electric auxiliary heating).

[0099] S7: Then obtain the actual execution power SZi of the current actuator in each partition connected domain, where the actual execution power SZi = min (required compensation power Pi, the maximum power of the actuator).

[0100] If the required compensation power Pi is greater than the maximum power of the actuator, an insufficient power alarm is triggered and the insufficient power alarm log is recorded.

[0101] Retrieve the preset power-command mapping table, output the actuator parameters based on the actual execution power SZi, and wait for execution. The actuator parameters include ventilation opening, heating duty cycle, etc.

[0102] S8: Every preset fixed frequency, repeat steps S1-S7 above. Each time the calculation is repeated, the prediction will be corrected based on the latest measured temperature and the updated remaining time. If the expected remaining transportation time is less than the preset time threshold, stop the new compensation calculation and keep the current instruction until unloading.

[0103] In summary, this invention achieves full-area temperature sensing of asphalt piles through multi-source heterogeneous data acquisition and three-dimensional temperature field modeling, solving the problems of incomplete coverage and inability to characterize spatial distribution in traditional single-point temperature measurement. Furthermore, based on temperature, boundary distance, thermal gradient, temperature change rate, and surface defects, it performs multi-dimensional zoning, accurately identifying overheated zones, core high-temperature zones, secondary high-temperature transition zones, edge low-temperature zones, and abnormal cooling zones. Differentiated control is adopted for different zones to achieve refined temperature control, avoiding energy waste and temperature control conflicts caused by overall temperature control, significantly improving control efficiency. Moreover, by setting zone control priorities, conflicting commands are uniformly coordinated and safety alarms are triggered, effectively avoiding temperature control failures caused by temperature control logic conflicts. Finally, based on the temperature change rate and remaining transportation time, on-site temperature prediction is performed, combined with power closed-loop compensation for early intervention, ensuring that the asphalt mixture unloading temperature remains stable within the allowable construction range, guaranteeing paving and compaction quality.

[0104] The threshold is set for comparative analysis of results to determine whether they are good or bad. The value of the threshold is determined by a combination of large-scale model analysis of sample data and human experience. It can also be adjusted appropriately based on seasonal or common-sense influencing factors.

[0105] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method of material temperature control for an asphalt concrete transport process, characterized by, Includes the following steps: Step 1: Based on the multi-source heterogeneous data acquisition and preprocessing of asphalt transport vehicles, construct a three-dimensional dynamic model T of the temperature field of the asphalt pile; Step 2: Construct the real-time feature dataset and establish association rules between temperature features and partition types, implement the division and writing of tag codes, and obtain the partition tag matrix L; Step 3: Traverse the partition label matrix L, group adjacent grids with the same label code into the same connected component, and complete the subsequent connected component boundary smoothing process to output the final partition connected component graph; Step 4: Based on the final partitioned connected domain graph, perform ventilation control in the overheated zone, heat preservation control in the secondary high temperature transition zone, heat replenishment calculation in the edge low temperature zone, and identification and heat replenishment triggering in the abnormal cooling zone according to the partition type. Process conflicting instructions according to preset priorities, generate a dynamic feedback control list, and realize closed-loop temperature control. Step 5: Predict the arrival temperature without intervention based on the temperature change rate of each connected domain, calculate the target reference temperature and the required temperature change according to the overheating / overcooling state, determine the compensation power and the actual execution power, output the actuator parameters, iteratively correct, stop the new calculation when the remaining transportation time is less than the preset threshold and maintain the current command until unloading.

2. A method of controlling the temperature of bituminous concrete during transport according to claim 1, wherein, The analysis process of T in the three-dimensional temperature field dynamic model of the stockpile is as follows: Temperature data from all temperature measurement points are collected at a preset fixed frequency. At the same time, transportation speed, transportation time and transportation route information are acquired in real time to form multi-source heterogeneous data. The multi-source heterogeneous data is preprocessed to form a standardized multi-source heterogeneous data pool. At the same time, with the front left corner of the carriage floor as the origin, a unified coordinate system for the carriage is established in the x-direction of carriage length, y-direction of width, and z-direction of height. The measurement points of each sensor are mapped to this coordinate system, and the carriage space is divided into uniform grids according to preset ΔX, ΔY and ΔZ. Based on a standardized multi-source heterogeneous data pool, the discrete measurement point temperature is extended to the entire grid, and the initial maximum temperature, minimum temperature, average temperature and temperature standard deviation of each grid are obtained to construct a three-dimensional temperature field dynamic model T of the stockpile. At the same time, the temperature change rate of each grid is calculated, and the data of each grid is mapped to the three-dimensional temperature field dynamic model T of the stockpile.

3. A method of controlling the temperature of asphalt concrete during transport according to claim 1, wherein The analysis process of the partition label matrix L is as follows: Based on the real-time three-dimensional temperature field dynamic model T of the stockpile, the current temperature value T, the distance d from the nearest car wall, the thermal gradient amplitude, and the temperature change rate are read for each grid to construct a real-time feature dataset. Set a temperature threshold benchmark for each zone and establish rules for the association between temperature characteristics and zone type; Based on the real-world feature dataset, the labels are written into the dynamic model T of the three-dimensional temperature field of the material pile according to the association rules between temperature features and zoning types, resulting in the zoning label matrix L. For the grid located on the surface of the material pile, an additional criterion is added: if the temperature value is less than the lower limit temperature of paving TL - preset critical value and the defect type is identified as depression or crack through surface feature image, then the corresponding grid is forcibly marked as an abnormal cooling zone.

4. The method for controlling the material temperature during the transportation of asphalt concrete according to claim 3, characterized in that, The association rules between temperature characteristics and partition types: If the temperature value is greater than or equal to the upper limit of the allowable paving temperature TH, it is determined to be an overheated zone and marked as 0. If the lower limit of the allowable paving temperature TL is less than or equal to the temperature value but less than the upper limit of the allowable paving temperature TH, and the distance from the boundary d is greater than the preset distance threshold, it is determined to be a core high-temperature zone and marked as 1. If the lower limit of the allowable paving temperature TL is less than or equal to the temperature value but less than the upper limit of the allowable paving temperature TH, and the distance from the boundary d is less than the preset distance threshold, it is determined to be a secondary high-temperature transition zone and marked as 2. If the temperature value is less than or equal to the lower limit of the allowable paving temperature TL, and the thermal gradient amplitude is less than the preset thermal gradient amplitude, it is determined to be an edge low-temperature zone and marked as 3. If the temperature value is less than or equal to the lower limit of the allowable paving temperature TL, and the thermal gradient amplitude is greater than or equal to the preset thermal gradient amplitude or the temperature change rate is less than the preset temperature change rate, it is determined to be an abnormal cooling zone and marked as 4.

5. The method for controlling the material temperature during the transportation of asphalt concrete according to claim 1, characterized in that, The analysis process of the final partitioned connected component graph is as follows: Traverse the partition label matrix L, group adjacent grids with the same label code into the same connected component, and assign a unique ID to each connected component; Set a minimum partition volume threshold Vmin, perform merging processing on isolated partitions whose volume is smaller than the minimum partition volume threshold Vmin, and smooth the boundaries of each partition to output the final partition connected component graph.

6. The method for controlling the material temperature during the transportation of asphalt concrete according to claim 1, characterized in that, The generation and analysis process of the dynamic feedback control list is as follows: Based on the final partitioned connected domain graph, the average temperature and overheating amount ΔC of the overheated zone connected domain with a marker code of 0 are obtained, and the ventilation opening of the adjustable vent located above the overheated zone connected domain is controlled. Extract all connected components of the sub-high temperature transition zone with a marker code of 2 to predict the temperature YT when it reaches the unloading port. Based on the judgment, trigger the enhanced insulation command and / or trigger the weakened insulation command. Extract the temperature deficit ΔK of each region corresponding to the connected domain of the edge low temperature zone marked with code 3, and then obtain the required heat replenishment of each edge low temperature zone connected domain. Extract the temperature change rate of the connected domain of the abnormal cooling zone marked with code 4. If the temperature change rate of a certain abnormal cooling zone connected domain is greater than the preset proportional coefficient × the average temperature change rate of the material pile, it is determined to be a local abnormality and a heat replenishment command is triggered. Obtain the set priority of each connected domain. When conflicting instructions are received in the same connected domain or adjacent areas, the instruction with higher priority is executed first, and a safety alarm instruction is triggered. A dynamic feedback control list is constructed based on ventilation opening, enhanced insulation command and / or weakened insulation command, required heat replenishment Qn, and triggered heat replenishment command.

7. The method for controlling the material temperature during the transportation of asphalt concrete according to claim 1, characterized in that, Step five includes the following: S1: Obtain the estimated remaining transportation time and target arrival temperature window of the asphalt transport vehicle, mark each connected component as i, where i is a natural number greater than zero, and obtain the temperature change rate vi of the two most recent preset fixed frequencies for each connected component; S2: Predict the temperature TXI of each connected domain when it reaches the unloading point under non-intervention conditions; S3: For each connected component, compare the temperature TXI with the target arrival temperature window, and output whether it is overheated, undercooled, or uncompensated. S4: Obtain the target reference temperature MTi corresponding to overheating or overcooling; S5: Obtain the required temperature change STi when overheating or overcooling occurs; S6: Based on the required temperature change STi when overheating or overcooling, obtain the required compensation power Pi, and according to the type of connected domain in each partition, obtain the maximum power of the actuator in each connected domain.

8. The method for controlling the material temperature during the transportation of asphalt concrete according to claim 7, characterized in that, It also includes S7: which then obtains the actual execution power SZi of the current actuator in each partition's connected domain; If the required compensation power Pi is greater than the maximum power of the actuator, an insufficient power alarm is triggered and the insufficient power alarm log is recorded. Retrieve the preset power-command mapping table, output the actuator parameters based on the actual execution power SZi, and wait for execution. The actuator parameters include ventilation opening and heating duty cycle. S8: Every preset fixed frequency, repeat steps S1-S7 above. Each time the calculation is repeated, the prediction will be corrected based on the latest measured temperature and the updated remaining time. If the expected remaining transportation time is less than the preset time threshold, stop the new compensation calculation and keep the current instruction until unloading.

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