Asphalt pavement unit longitudinal control method and temperature loss simulation analysis system

Abstract

The invention discloses an asphalt pavement unit longitudinal control method and a temperature loss simulation analysis system, and relates to the technical field of asphalt pavement heating. The method comprises the following steps: constructing a longitudinal formation system; based on the longitudinal formation system, an infrared temperature sensing device is used for determining the road surface temperature and the milling temperature of the set depth under the road, and a position measuring device is used for determining the vehicle distance between every two adjacent single vehicles; according to the road surface temperature, the milling temperature of the set depth under the road, the vehicle distance and the artificial potential field function, determining a longitudinal heating strategy of the asphalt pavement; the asphalt pavement longitudinal heating strategy comprises the single vehicle running speed and the vehicle team control distance. The heating degree can be adjusted by controlling the longitudinal running speed of the heating unit, and therefore simulation analysis of temperature loss can be conveniently achieved.

Description

Technical Field

[0001] The invention relates to the technical field of asphalt pavement heating technology, and in particular to an asphalt pavement unit longitudinal control method and a temperature loss simulation analysis system. Background Art

[0002] According to statistics from the Ministry of Transport, asphalt pavement is the main structure used in Chinese roads. Under the long-term influence of natural factors and vehicle loads, the changing temperature stress field will cause non-load cracks in the pavement structure, and the cracks may continue to expand until they penetrate the entire road structure. As a mature asphalt pavement pre-maintenance technology, in-situ hot recycling technology can carry out targeted recycling mixture design based on factors such as the original road traffic, design parameters and material properties, and repair and maintain early diseased asphalt pavements according to specific construction process.

[0003] However, asphalt is a poor conductor of heat, and it is difficult to heat the deep asphalt pavement material. No matter whether infrared heating, hot air heating or intermittent heating are used to change the heating process, it is not possible to ensure the heating efficiency and heating uniformity. The heating efficiency and heating uniformity are directly related to the construction quality of the in-situ hot regeneration of the asphalt pavement and the overall road performance of the regenerated pavement. In addition, the surrounding environment has a significant impact on the temperature loss during the entire process of in-situ hot regeneration of the asphalt pavement. Therefore, the construction quality of in-situ hot regeneration of the same section of road depends entirely on the experience of the workers.

[0004] Therefore, ensuring the heating temperature of the asphalt pavement is the key to achieving high-quality in-situ hot regeneration. However, there is currently a lack of feasible pavement temperature control solutions at construction sites. Existing infrared technology is mainly used to measure the surface temperature of objects, and usually relies on real-time monitoring to adjust the working parameters of the regeneration unit, but this often leads to problems such as excessively high or low pavement temperatures, resulting in uneven heating levels of the pavement in the same operating section, which affects the thoroughness of milling, and further affects the service life and driving comfort of the pavement. In addition, there is a delay in regulating the heating unit through manual observation, which requires a high level of experience from the workers and is prone to problems such as incomplete milling or burning of the pavement.

[0005] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention

[0006] The purpose of the present invention is to provide a longitudinal control method of an asphalt pavement unit and a temperature dissipation simulation analysis system, which can adjust the heating degree by controlling the longitudinal travel speed of the heating unit, thereby facilitating the simulation analysis of temperature dissipation.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] A longitudinal control method for an asphalt pavement unit, comprising:

[0009] Construct a longitudinal formation system; the longitudinal formation system includes a plurality of heating bicycles and construction bicycles; the bicycles are arranged according to the set convoy spacing and initial driving speed, and infrared temperature sensors and position measurement devices are installed at the front and rear of each bicycle;

[0010] Based on the longitudinal formation system, an infrared temperature sensor device is used to determine the road surface temperature and the milling temperature of a set depth under the road, and a position measuring device is used to determine the vehicle spacing between each two adjacent bicycles;

[0011] The longitudinal heating strategy of the asphalt pavement is determined according to the road surface temperature, the milling temperature at the set depth under the road, the vehicle spacing and the artificial potential field function; the longitudinal heating strategy of the asphalt pavement includes the single vehicle driving speed and the fleet control spacing.

[0012] Optionally, the heating vehicle includes: an on-site hot air heater, an on-site heating milling machine and an on-site microwave heater.

[0013] Optionally, the construction vehicles include an on-site remixer and a dump truck.

[0014] Optionally, the set fleet spacing is 5 cm.

[0015] Optionally, the artificial potential field function is expressed as:

[0016]

[0017] Among them, G ij represents the potential field between the i-th car and the j-th car; d i represents the distance between the i-th vehicle and the preceding vehicle; x j represents the coordinates of the jth vehicle; x i represents the coordinates of the i-th car; T max Indicates the maximum acceptable temperature; T i Indicates the current ground temperature of the i-th car heating.

[0018] The present invention also provides an asphalt pavement temperature loss simulation analysis system, which is applied to the above method and includes:

[0019] A model building module is used to establish a numerical simulation model for simulating the heating temperature field of asphalt pavement;

[0020] The analysis simulation module is used to load the set boundary conditions and heat source related parameters into the numerical simulation model, perform simulation based on the longitudinal control method of the asphalt pavement unit, calculate the heating process of the asphalt pavement under different climatic conditions, and obtain the temperature field distribution of the asphalt pavement.

[0021] Optionally, the numerical simulation model in the model building module is established using Fluent simulation software to describe the collective shape and physical properties of the asphalt pavement.

[0022] Optionally, the boundary conditions in the analysis and simulation module are composed of multiple climate factors, and the heat source related parameters include parameters of a hot air heating source.

[0023] The advantages of the present invention compared with the prior art are:

[0024] 1. The present invention discloses a longitudinal control method for an asphalt pavement unit and a temperature dissipation simulation analysis system, the method comprising constructing a longitudinal formation system; based on the longitudinal formation system, using an infrared temperature sensor device to determine the road surface temperature and the milling temperature at a set depth under the road, and using a position measurement device to determine the vehicle spacing between each two adjacent vehicles; determining the longitudinal heating strategy for the asphalt pavement according to the road surface temperature, the milling temperature at a set depth under the road, the vehicle spacing, and an artificial potential field function; the longitudinal heating strategy for the asphalt pavement includes the vehicle speed and the control spacing of the fleet. The present invention can adjust the degree of heating by controlling the longitudinal speed of the heating unit, thereby facilitating the simulation analysis of temperature dissipation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic flow chart of the longitudinal control method of the asphalt pavement unit of the present invention.

[0026] Figure 2 This is a simplified schematic diagram of the longitudinal formation system arrangement of the on-site heat regeneration unit in this embodiment.

[0027] Figure 3 This is a vehicle control flow chart for a single vehicle in this embodiment.

[0028] Figure 4 Schematic diagram of the spacing error between single machines in the unit in this embodiment. DETAILED DESCRIPTION

[0029] In order to make the contents of the present invention more clearly understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0030] The purpose of the present invention is to provide a longitudinal control method of an asphalt pavement unit and a temperature dissipation simulation analysis system, which can adjust the heating degree by controlling the longitudinal travel speed of the heating unit, thereby facilitating the simulation analysis of temperature dissipation.

[0031] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figure 1 As shown, the present invention provides a longitudinal control method for an asphalt pavement unit, comprising:

[0033] Step 100: Construct a longitudinal formation system; the longitudinal formation system includes multiple heating bicycles and construction bicycles; the bicycles are arranged according to the set fleet spacing and initial driving speed, and infrared temperature sensors and position measurement devices are installed at the front and rear of each bicycle.

[0034] Step 200: Based on the longitudinal formation system, an infrared temperature sensor device is used to determine the road surface temperature and the milling temperature of a set depth under the road, and a position measurement device is used to determine the vehicle spacing between each two adjacent bicycles.

[0035] Step 300: Determine the longitudinal heating strategy of the asphalt pavement according to the road surface temperature, the milling temperature at the set depth under the road, the vehicle spacing and the artificial potential field function; the longitudinal heating strategy of the asphalt pavement includes the single vehicle speed and the fleet control spacing.

[0036] Based on the above steps, the following specific embodiments are provided.

[0037] In this embodiment, the degree of heating can be adjusted by controlling the longitudinal travel speed of the heating unit through a simulation method. Compared with the traditional on-site heat regeneration method, this technology has better technical adaptability and environmental adaptability.

[0038] First, a longitudinal speed control method for the unmanned regeneration unit is constructed. With the help of unmanned driving technology in the automotive field, the asphalt pavement in-situ hot regeneration unit can realize single-machine unmanned operation. The unmanned construction of the unit can be realized by coordinated control of the unit on the road to be constructed, which can reduce the dependence of the pavement construction quality on the operator's experience and improve the safety of construction.

[0039] The simplified crew formation system is as follows: Figure 2 As shown, in order to accurately control the fleet, two levels of control can be adopted: single vehicle control and fleet spacing control.

[0040] For single-vehicle control: infrared temperature sensors are installed at the front and rear of each vehicle to obtain the real-time temperature of the road surface. The vehicle speed is mainly controlled by two parts: 1. The temperature of the road surface; 2. The temperature of the road bottom; the temperature of the milling area 5 cm deep under the road can be estimated by the heating temperature of the road surface and the derivation of the simulation model. The control flow chart of a single vehicle is as follows: Figure 3 shown.

[0041] For fleet spacing control: Install position measurement devices in front and behind each vehicle to obtain the precise position of each vehicle. Figure 4 For example, where d is the ideal vehicle distance and △ is the actual distance, the distance error e = d-△. The artificial potential field method is a virtual force method proposed by Khatib. Its basic idea is to design the movement of the robot in the surrounding environment into a movement in an abstract artificial gravitational field. The front car generates "gravity" with the rear car, and the real-time temperature of the road surface generates not only "gravity" but also "repulsion" to the rear car. The artificial potential field function is shown below:

[0042]

[0043] Among them, G ij represents the potential field between the i-th car and the j-th car; d i represents the distance between the i-th vehicle and the preceding vehicle; x j represents the coordinates of the jth vehicle; x i represents the coordinates of the i-th car; T max Indicates the maximum acceptable temperature; T i Indicates the current ground temperature of the i-th car heating.

[0044] Based on the longitudinal speed control method of the unmanned regeneration unit mentioned above, according to the heat transfer theory and the principle of hot air circulation heating, the heat conduction equation and boundary conditions suitable for the heating temperature field of the on-site wind-heated regeneration asphalt pavement are established, and the analytical solution of the temperature field is derived; with the help of Fluent simulation software, a temperature field simulation model under complex conditions is established, and the effects of different factors on the pavement heating temperature field are systematically analyzed.

[0045] Regarding the establishment of the simulation model: In order to study the impact of different climatic factors on the heating efficiency of asphalt pavement, the Fluent simulation software can be used to establish a numerical simulation model to simulate the heating temperature field of the asphalt pavement.

[0046] First, using Fluent simulation software, a numerical model based on finite element or finite volume method can be constructed to describe the geometry and physical properties of the asphalt pavement. The model considers the physical processes of heat conduction, radiation and convection of the asphalt pavement.

[0047] Next, climate factors, such as wind speed and rainfall, are introduced as boundary conditions of the model. By adjusting the values ​​of these climate factors, the effects of different climate conditions on the heating efficiency of the asphalt pavement can be simulated.

[0048] In the numerical simulation model, the parameters of the hot air heating source can be set, such as temperature, flow rate, and heating time. By running the simulation, the heating process of the asphalt pavement under different climatic conditions can be calculated, and the temperature field distribution of the asphalt pavement can be obtained.

[0049] By analyzing the simulation results, it is possible to study the effect of different climate factors on the heating efficiency of the asphalt pavement. For example, it is possible to see whether the heat transfer effect of the hot air is hindered under high wind speed conditions, or whether the heating process is affected by moisture in the case of rainfall.

[0050] Such numerical simulation models can help optimize the hot air heating process, predict the heating effect under different climate conditions, and develop corresponding strategies to improve heating efficiency. At the same time, the model can also provide a reference for pavement maintenance and design to adapt to the actual situation under different climate conditions.

[0051] In summary, this embodiment aims at the construction process and process of the regeneration unit of the hot asphalt pavement in situ, and studies the mathematical modeling and collaborative control method of the longitudinal movement of the unit. First, based on the thermal conductivity of asphalt, simulation is performed through Fluent, the influence of different environmental factors on thermal conductivity is discussed, and a reasonable temperature prediction model is established. Then, the mathematical model of a single machine is established according to vehicle dynamics, and then the spacing error model between each single machine is obtained. The kinematic model of the unit cluster is regarded as the servo constraint of the longitudinal control system, and the stability analysis of the control system is performed using Lyapunov stability theory. The kinematic model of the unit cluster and the longitudinal speed control method of the unit proposed in this embodiment have certain feasibility. The heating level of the road surface in the same working section is controlled as a whole to extend the service life of the road surface and driving comfort.

[0052] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0053] The present invention and its implementation methods are described above, and such description is not restrictive. In short, if ordinary technicians in the field are inspired by it, without departing from the purpose of the invention, they can design structures and embodiments similar to the technical solution without creativity, which should all fall within the protection scope of the present invention.

Claims

1. A longitudinal control method for an asphalt pavement unit, characterized in that: The following steps are involved: Step 100: construct a longitudinal formation system: the longitudinal formation system includes a plurality of heating bicycles and construction bicycles; the bicycles are arranged according to the set convoy spacing and initial driving speed, and infrared temperature sensors and position measurement devices are installed at the front and rear of each bicycle; Step 200: Based on the longitudinal formation system, an infrared temperature sensor device is used to determine the road surface temperature and the milling temperature of a set depth under the road, and a position measurement device is used to determine the vehicle spacing between each two adjacent bicycles; Step 300: Determine the longitudinal heating strategy of the asphalt pavement according to the road surface temperature, the milling temperature at the set depth under the road, the vehicle spacing and the artificial potential field function; the longitudinal heating strategy of the asphalt pavement includes the single vehicle speed and the fleet control spacing.

2. The longitudinal control method of an asphalt pavement unit according to claim 1, characterized in that: The heating bicycle comprises: an on-site hot air heating machine, an on-site heating milling machine and an on-site microwave heating machine.

3. The longitudinal control method of an asphalt pavement unit according to claim 1, characterized in that: The construction vehicles include an on-site remixing machine and a dump truck.

4. The longitudinal control method of an asphalt pavement unit according to claim 1, characterized in that: The set convoy spacing is 5 cm.

5. The longitudinal control method of an asphalt pavement unit according to claim 1, characterized in that: The artificial potential field function is expressed as: Among them, G ij represents the potential field between the i-th car and the j-th car; d i represents the distance between the i-th vehicle and the preceding vehicle; x j represents the coordinates of the jth vehicle; x i represents the coordinates of the i-th car; T max Indicates the maximum acceptable temperature; T i Indicates the current ground temperature of the i-th car heating.

6. A temperature loss simulation analysis system for asphalt pavement, applied to the method described in any one of claims 1 to 5, characterized in that: include: A model building module is used to establish a numerical simulation model for simulating the heating temperature field of asphalt pavement; The analysis simulation module is used to load the set boundary conditions and heat source related parameters into the numerical simulation model, perform simulation based on the longitudinal control method of the asphalt pavement unit, calculate the heating process of the asphalt pavement under different climatic conditions, and obtain the temperature field distribution of the asphalt pavement.

7. The asphalt pavement temperature loss simulation analysis system according to claim 6, characterized in that: The numerical simulation model in the model building module is established using Fluent simulation software to describe the collective shape and physical properties of the asphalt pavement.

8. The asphalt pavement temperature loss simulation analysis system according to claim 6, characterized in that: The boundary conditions in the analysis and simulation module are composed of a variety of climate factors, and the heat source related parameters include parameters of the hot air heating source.

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