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CN-122017823-A - Asphalt concrete heat induction healing safety regulation and control method based on fatigue damage assessment

CN122017823ACN 122017823 ACN122017823 ACN 122017823ACN-122017823-A

Abstract

The invention belongs to the technical field of automatic control, and particularly relates to a safety regulation and control method for asphalt concrete heat induction healing based on fatigue damage evaluation. The method comprises the following steps of 1, scanning an asphalt concrete pavement of a target road section through a vehicle-mounted detection device to generate a unit sequence to be healed, 2, moving a phased array microwave heating device to the position above a current unit to be healed, building a dielectric constant three-dimensional grid model based on a dielectric constant three-dimensional distribution data body, determining a focusing target point, focusing microwave energy on the focusing target point to form a three-dimensional focusing hot zone, monitoring surface temperature and executing heat preservation control, and 3, retesting the healed current unit to be healed, counting the healing standard rate of the road section, and outputting a safety regulation report. The invention solves the technical problem of accurate focusing of microwave energy in the heterogeneous asphalt concrete medium, and improves the pertinence and effectiveness of heat-induced healing.

Inventors

  • YANG HAIE
  • LI JINGBIN
  • SUN HAIDONG
  • Sang Boyang
  • Bai Zongyang

Assignees

  • 聊城市交通发展有限公司

Dates

Publication Date
20260512
Application Date
20260129

Claims (10)

  1. 1. The asphalt concrete heat induction healing safety regulation and control method based on fatigue damage evaluation is characterized by comprising the following steps of: Step1, fatigue damage state identification and to-be-healed area determination, namely scanning an asphalt concrete pavement of a target road section through a vehicle-mounted detection device to obtain pavement images and ground penetrating radar echo data, extracting crack density values and crack connectivity values based on the pavement images, generating a dielectric constant three-dimensional distribution data body based on the ground penetrating radar echo data and extracting crack depth values; Step 2, phased array microwave directional heating based on a reverse time focusing algorithm, namely moving a phased array microwave heating device to the position above a current unit to be healed, establishing a dielectric constant three-dimensional grid model based on a dielectric constant three-dimensional distribution data body, determining a focusing target point, performing reverse time focusing phase calculation, setting a virtual point source at the focusing target point, simulating an electromagnetic wave propagation process, acquiring receiving phases of corresponding positions of all microwave radiation units, performing phase conjugation processing on the receiving phases to obtain transmitting phases, loading the transmitting phases to all microwave radiation units, controlling all microwave radiation units to simultaneously transmit microwave signals, focusing microwave energy on the focusing target point to form a three-dimensional focusing hot zone, monitoring surface temperature, and performing heat preservation control; And 3, performing retest on the current healed units after healing, obtaining a healed crack density value, a healed crack connectivity value and a healed maximum crack depth value, calculating the reduction rate of each index and judging the healing state, traversing all the healed units in the unit sequence to be healed, counting the healing standard rate of the road section and outputting a safety regulation report.
  2. 2. The method of claim 1, wherein the step 1 of extracting the crack density value and the crack connectivity value based on the pavement image comprises inputting the pavement image into a crack segmentation model, outputting a crack binary mask image, performing skeleton refinement treatment on the crack binary mask image to obtain a crack skeleton image with single pixel width, counting the total number of pixels of the cracks on the crack skeleton image and dividing the total number of pixels of the cracks by the pavement area covered by the image to obtain the crack density value, and identifying all crack crossing points on the crack skeleton image, counting the number of crack crossing points and dividing the total number of pixels of the cracks to obtain the crack connectivity value.
  3. 3. The method according to claim 2, wherein in the step 1, the process of generating the dielectric constant three-dimensional distribution data body based on the ground penetrating radar echo data and extracting the crack depth value comprises the steps of performing time-depth conversion on the ground penetrating radar echo data to generate the dielectric constant three-dimensional distribution data body of the pavement structure, marking the area with the dielectric constant lower than the asphalt reference dielectric constant as a crack gap area in the dielectric constant three-dimensional distribution data body, and extracting the maximum depth value of each crack gap area as the crack depth value.
  4. 4. The method according to claim 3, wherein in the step 1, the process of determining the units to be healed and generating the unit sequence to be healed comprises dividing the pavement into square grid units with equal side lengths, calculating a crack density value, a crack connectivity value and a maximum crack depth value inside each grid unit, marking the corresponding grid unit as the unit to be healed when the crack density value of any grid unit exceeds a density threshold value, or the crack connectivity value exceeds the connectivity threshold value, or the maximum crack depth value exceeds a depth threshold value, and sorting all the units to be healed according to the maximum crack depth value from large to small to generate the unit sequence to be healed.
  5. 5. The method of claim 4, wherein in step 2, the phased array microwave heating apparatus comprises a plurality of microwave radiating elements arranged in a rectangular array, each microwave radiating element being configured with a separate phase shifter and power amplifier, the phase of the phase shifter being adjusted in a range of 0 degrees to 360 degrees.
  6. 6. The method according to claim 5, wherein in the step 2, the process of establishing the dielectric constant three-dimensional grid model based on the dielectric constant three-dimensional distribution data body and determining the focusing target point comprises the steps of intercepting local dielectric constant distribution data of a corresponding area of the current unit to be healed from the dielectric constant three-dimensional distribution data body, dispersing a spatial range covered by the local dielectric constant distribution data into cube grids, storing dielectric constant values of corresponding positions of each cube grid to form the dielectric constant three-dimensional grid model, wherein the horizontal position of the focusing target point is a geometric center where the density of cracks in the current unit to be healed is maximum, and the depth position of the focusing target point is one half of the maximum crack depth value of the current unit to be healed.
  7. 7. The method according to claim 6, wherein in the step 2, the process of performing reverse time focusing phase calculation includes setting a virtual point source at a focusing target point position, transmitting spherical electromagnetic waves to a surrounding space by the virtual point source, simulating propagation of the spherical electromagnetic waves in a dielectric constant three-dimensional grid model by a time domain finite difference method, recording electric field time domain waveforms at corresponding positions right below each microwave radiation unit when the spherical electromagnetic waves propagate to the top surface of the dielectric constant three-dimensional grid model, selecting a complete period with the largest amplitude in the electric field time domain waveforms as a reference period for the electric field time domain waveforms recorded at the position right below each microwave radiation unit, and recording a phase angle of a moment of an electric field zero crossing point in the reference period from negative to positive relative to a starting moment of the reference period as a receiving phase of the corresponding microwave radiation unit.
  8. 8. The method of claim 7, wherein the step of performing phase conjugation processing on the received phases to obtain the transmitted phases includes calculating a difference of 360 degrees minus the received phases as the transmitted phase of the corresponding microwave radiating units for each received phase of the microwave radiating units, subtracting 360 degrees if the difference exceeds 360 degrees, adding 360 degrees if the difference is negative, and ensuring the range of the transmitted phase to be 0 degrees to 360 degrees, loading the transmitted phases of the microwave radiating units to the corresponding phase shifters respectively, and controlling all the microwave radiating units to transmit microwave signals simultaneously, so that the microwave signals transmitted by the microwave radiating units are superimposed in phase at the focus target point position to form a three-dimensional focus hot zone.
  9. 9. The method according to claim 8, wherein the process of monitoring the surface temperature and performing the thermal insulation control in step 2 includes continuously acquiring the surface temperature distribution image of the current unit to be healed by the thermal infrared imager, extracting a maximum temperature value and an average temperature value from each frame of the surface temperature distribution image, reducing the power amplifier output power of all the microwave radiating units when the maximum temperature value reaches a preset maximum temperature upper threshold, entering a thermal insulation stage, periodically detecting the average temperature value in the thermal insulation stage, increasing the power amplifier output power when the average temperature value is lower than a preset average temperature lower threshold, reducing the power amplifier output power when the average temperature value is higher than the preset average temperature upper threshold, and turning off all the microwave radiating units after the thermal insulation stage is finished.
  10. 10. The method of claim 9 wherein in step 3, the step of calculating the rate of decrease of each index and determining the healing status includes calculating a difference between the fracture density value and the healed fracture density value, dividing the difference by the fracture density value to obtain a rate of decrease of the fracture density, calculating a difference between the fracture connectivity value and the healed fracture connectivity value, dividing the difference by the fracture connectivity value to obtain a rate of decrease of the fracture connectivity, calculating a difference between the maximum fracture depth value and the healed maximum fracture depth value, dividing the difference by the maximum fracture depth value to obtain a rate of decrease of the fracture depth, marking the current unit to be healed when the rate of decrease of the fracture density, the rate of decrease of the fracture connectivity and the rate of decrease of the fracture depth are all greater than a preset rate of decrease threshold, counting a ratio of the number of units to be healed to the number of all processed units to be healed as a rate of the healing of the road, determining a safety status mark of the road to be healed, and outputting a safety regulation report.

Description

Asphalt concrete heat induction healing safety regulation and control method based on fatigue damage assessment Technical Field The invention relates to the technical field of automatic control, in particular to an asphalt concrete heat induction healing safety regulation and control method based on fatigue damage evaluation, and belongs to industrial control software. Background Asphalt concrete, which is a viscoelastic material, has a self-healing ability under specific temperature conditions. When the temperature of the pavement is increased to be above the softening point of asphalt, the viscosity of the asphalt cement is reduced, the molecular chains acquire fluidity, and the molecular chains can interdiffuse and intertwine across the crack interface, so that the healing and closing of the cracks are realized. The characteristic provides a new technical idea for pavement maintenance, namely, the asphalt concrete is induced to self-heal by a manual heating means, so that the fatigue crack is actively repaired. Compared with the traditional passive repair method, the thermal induction healing technology can intervene in the early stage of crack development, the repair effect is better, the construction efficiency is higher, and the influence on traffic is smaller. The heating modes for the heat-induced healing of asphalt concrete at present mainly comprise infrared heating, hot air heating, microwave heating and the like. Infrared heating transfers heat to the surface of the pavement through infrared radiation and is conducted from the surface to the inside. The heating mode has higher energy utilization efficiency, but the heat transfer depends on the heat conduction process, so that the surface temperature of the pavement is far higher than the internal temperature, the surface asphalt is easy to overheat and age, and the deep cracks can not reach the effective healing temperature. The hot air heating adopts high-temperature airflow to heat the pavement, has the temperature gradient problem similar to infrared heating, is greatly influenced by the ambient wind speed, and is difficult to ensure the heating uniformity. The microwave heating utilizes the interaction of a microwave electromagnetic field and medium molecules to generate heat, so that the heating of a pavement structure can be realized, and the problem of overlarge temperature gradient is relieved to a certain extent. However, the existing microwave heating devices generally use a single radiation source or a simple radiation source array, the distribution of microwave energy inside the pavement is mainly determined by the characteristics of the medium, the precise control capability of the heating area and the heating depth is lacking, and it is difficult to concentrate heat at the crack positions needing healing. Asphalt concrete pavement is a heterogeneous medium consisting of asphalt cement, mineral aggregate and voids, and the dielectric constants of the different components are significantly different. When microwaves propagate in such non-uniform media, refraction, scattering and multipath effects can occur, resulting in energy distributions that deviate from expectations. Although the traditional phased array beam forming technology can realize the directional heating of target points in uniform media, the phase calculation is based on the assumption of the uniform media, the phase distortion caused by non-uniform media cannot be accurately compensated, and the actual focusing effect is often greatly reduced. Therefore, how to achieve accurate energy focusing of crack locations in a heterogeneous asphalt concrete medium is a key technical challenge faced by heat-induced healing techniques. Disclosure of Invention The invention mainly aims to provide a safe regulation and control method for asphalt concrete heat induction healing based on fatigue damage assessment, which realizes closed-loop regulation and control of damage identification, directional heating and effect verification, solves the technical problem of accurate focusing of microwave energy in a heterogeneous asphalt concrete medium, and improves pertinence and effectiveness of heat induction healing. In order to solve the technical problems, the invention provides an asphalt concrete heat induction healing safety regulation and control method based on fatigue damage evaluation, which comprises the following steps: Step1, fatigue damage state identification and to-be-healed area determination, namely scanning an asphalt concrete pavement of a target road section through a vehicle-mounted detection device to obtain pavement images and ground penetrating radar echo data, extracting crack density values and crack connectivity values based on the pavement images, generating a dielectric constant three-dimensional distribution data body based on the ground penetrating radar echo data and extracting crack depth values; Step 2, phased array microwave directional heating based on