Road laser deicing parameter determination method based on power threshold and weight optimization

Abstract

The invention discloses a road laser deicing parameter determination method based on power threshold and weight optimization, belongs to the technical field of laser application, and aims to solve the problem of poor deicing effect or damage to pavement materials caused by improper selection of laser parameters. The method comprises the following steps: S1, preparing a standardized ice-coated asphalt mixture test piece; s2, determining a scanning path and a scanning speed of a laser head; s3, preliminarily estimating laser power parameters; s4, performing a laser deicing experiment under a controllable environment condition, and synchronously monitoring an ice layer state and a surface temperature field of the test piece; s5, determining a laser power threshold value; and S6, based on an analytic hierarchy process, determining an efficiency weight and a safety weight for different deicing scenes, and calculating an optimal laser deicing power P.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of laser application, and in particular to a laser parameter optimization determination method for road deicing. BACKGROUND

[0002] According to statistics, nearly 80% of roads in China are affected by ice and snow weather, which easily causes traffic accidents and brings great safety hazards. At present, the common road icing removal methods mainly include mechanical deicing method, snow-melting agent deicing method and manual deicing method. The mechanical deicing method is low in efficiency, and mechanical scraping and rolling directly impact the road surface, which easily causes damage to the road surface; the snow-melting agent deicing method accelerates the damage of the road surface structure and its auxiliary facilities, and pollutes the surrounding soil and water environment; the manual deicing method is extremely low in deicing efficiency, and has safety hazards during operation. In summary, the limitations of the existing road deicing methods are increasingly prominent, and the traditional mechanical, snow-melting agent and manual deicing methods have problems such as low efficiency, damage to the road surface and environmental pollution, and it is urgent to develop a new road deicing method which is efficient, environmentally friendly and safe.

[0003] The laser deicing technology gradually becomes a new technology to replace the traditional deicing method due to its advantages of non-contact, non-pollution and high efficiency. The principle of the laser deicing technology is to irradiate the ice layer with a high-energy-density laser beam, and to realize the separation of the ice layer from the substrate or the ablation of the ice layer itself through energy conversion and transmission. The laser deicing technology is currently mainly applied to power transmission lines and insulators, and is gradually introduced into the transportation field. Invention patents (CN 119640723 A) and (CN 119531293 A) integrate the laser head into a deicing device with reciprocating vibration function, and assemble it in front of the vehicle for road deicing, but the patents do not disclose how to determine reasonable laser parameters.

[0004] The current road laser deicing technology lacks a systematic parameter selection method, and the parameters are mainly dependent on experience or trial and error, which is difficult to balance between deicing efficiency and road safety, and is easy to cause poor deicing effect or damage to the road surface. For example, although the existing patents integrate the laser head into the deicing device, they do not disclose how to scientifically determine the laser parameters according to the ice layer conditions and environmental factors. Therefore, there is an urgent need in the field to develop a method for accurately and adaptively determining the laser deicing parameters to realize efficient and safe deicing operation. SUMMARY

[0005] In order to solve the problem of poor deicing effect or damage to the road surface caused by improper selection of laser parameters, the present application provides a road laser deicing parameter determination method based on power threshold and weight optimization.

[0006] The road laser deicing parameter determination method based on power threshold and weight optimization provided by the present application comprises the following steps:

[0007] S1, preparing a standardized ice-coated asphalt mixture test piece;

[0008] S2, determining the scanning path and scanning speed of the laser head according to the test piece size and deicing vehicle operation mode;

[0009] S3, preliminarily estimating the laser power parameter based on Lambert-Beer's law according to the target ice layer thickness;

[0010] S4, performing laser deicing experiments under controllable environmental conditions, and synchronously monitoring the ice layer state and test piece surface temperature field;

[0011] S5, determining the laser power threshold: taking the minimum power when the ice shedding rate of the inclined ice reaches 90% as the minimum effective deicing power , and taking the maximum power when the highest temperature of the test piece surface reaches the asphalt softening point temperature minus 10°C as the maximum safe power ;

[0012] S6, determining the efficiency weight and safety weight for different deicing scenarios based on the analytic hierarchy process, and calculating the optimal laser deicing power P through the formula .

[0013] Preferably, in step S1, the preparation of the ice-coated asphalt mixture test piece specifically comprises: preparing an asphalt mixture rutting plate test piece according to the specification; calculating the required water mass according to the target ice layer thickness h, ice density , and test piece area S using the volume inverse mass method; and uniformly spraying water on the surface of the low-temperature treated test piece until the consumed water mass is m, to complete the ice coating.

[0014] Preferably, in step S2, the scanning path is: controlling the laser head to make uniform linear motion along the longitudinal direction of the test piece at a speed , and simultaneously controlling the laser head to make high-frequency reciprocating motion along the transverse direction of the test piece at a speed , so that the laser beam forms a continuous zigzag scanning trajectory on the surface of the test piece.

[0015] Preferably, in step S3, the preliminary estimation of the laser power parameter based on Lambert-Beer's law specifically comprises:

[0016] establishing an energy attenuation model of the laser in the ice layer based on Lambert-Beer's law:

[0017]

[0018] wherein:​​​​ is the residual power of laser when it reaches the ice-road interface; is the incident laser power; is the absorption coefficient of ice to the specific wavelength laser; is the thickness of target ice layer;

[0019] For a specific wavelength laser, the residual power of laser when it reaches the ice-road interface is calculated by using the above formula for different ice layer thicknesses, and the residual power value of the inclined ice layer at the time of ice shedding is determined by this method, and then the appropriate incident laser power range corresponding to different ice layer thicknesses is determined as the initial laser power.

[0020] Preferably, in step S4, the laser deicing experiment is carried out under controllable environmental conditions, and the process of synchronously monitoring the ice layer state and the road surface temperature field is as follows: the prepared ice-coated asphalt mixture test piece is placed on the experimental platform in the constant temperature and humidity box, and the temperature is controlled for more than 6 hours to ensure that the temperature of the ice-coated asphalt mixture test piece is consistent with the environmental temperature; the water cooling system and the laser are started, the parameters are set according to the initial laser power, the deicing experiment is carried out by using the above-mentioned specified laser scanning speed and scanning path; the monitoring system is started synchronously, the high-speed camera records the ice layer cracking and ablation process, and the infrared thermal imager collects the test piece surface temperature field once per second.

[0021] Preferably, in step S5, the process of obtaining the inclined ice shedding rate D is as follows:

[0022] After the deicing experiment in step S4 is completed, the laser is turned off, and the angle between the experimental platform and the horizontal plane in the constant temperature and humidity box is slowly adjusted to 45 degrees; if the ice layer sheds at this angle, the residual power value of the inclined ice layer at the time of ice shedding is recorded, and the inclined ice shedding rate D is calculated according to the following formula:

[0023]

[0024] wherein, is the total mass of the ice layer of the test piece, is the total mass of the shed ice layer.

[0025] Preferably, 1% of the maximum output power of the laser is taken as the laser power unit adjustment amount, steps S4 and S5 are repeatedly executed, and the minimum effective deicing power that meets the deicing effect is obtained and the maximum safe power .

[0026] Preferably, in step S6, the weight coefficients and are determined based on the analytic hierarchy process, and specifically include:

[0027] S61. Construct a hierarchical model, where the target layer is the parameter weight allocation and the criterion layer includes de-icing efficiency and road safety.

[0028] S62. Construct a judgment matrix A. Experts compare the importance of de-icing efficiency and road safety pairwise for different scenarios, using the classic AHP method. The scaling method is used to score and construct the judgment matrix A:

[0029]

[0030] in, This represents a scale value indicating the importance of de-icing efficiency relative to road safety.

[0031] S63. Calculation of weighting coefficients: Based on the judgment matrix A, the efficiency weights are calculated using the following formula. and safety weight :

[0032] .

[0033] The beneficial effects of this invention are as follows: For road laser de-icing applications, this invention establishes a laser de-icing experimental system that can simulate the real road de-icing environment and proposes a standardized process for testing laser de-icing performance. It proposes a method for determining the laser power threshold based on the ice shedding rate at the slope angle and the road surface softening temperature, and based on this threshold, establishes an optimal laser power selection method based on de-icing sensitivity. By quantifying the importance of safety and efficiency through weighting coefficients, it ensures de-icing efficiency while avoiding road surface damage, providing a basis for parameter selection of the laser de-icing system. Specifically, this includes the following points:

[0034] (1) Establish a standardized experimental procedure for laser de-icing.

[0035] Asphalt mixture rutting slab specimens were prepared using the standard preparation method and the ice layer volume back-calculation mass method; laser scanning speed and path were obtained based on specimen dimensions; and Lambertian laser scanning was used. Beer's Law determines the initial parameters of laser power; a standardized experimental procedure for laser de-icing experiments, from specimen preparation to evaluation of de-icing effect, is proposed.

[0036] (2) A method for determining the laser power threshold based on the slope angle, ice shedding rate, and road surface softening temperature is proposed.

[0037] Laser de-icing experiments were conducted using specimens with varying ice thicknesses. During the process, the road surface temperature was monitored in real-time using a monitoring system, with the highest temperature reaching the specified temperature (asphalt softening point temperature). At 10℃, the corresponding power is determined as the maximum safe laser power; after the experiment, the specimen is tilted at 45 degrees, and the percentage of the mass of the detached ice layer to the total mass of the ice layer is calculated. When the tilt angle ice detachment rate is 90%, the corresponding power is the minimum effective laser power.

[0038] (3) Determine the optimal laser power selection method based on de-icing sensitivity

[0039] The optimal power is calculated by weighting safety and efficiency, and safety weight coefficient and efficiency weight coefficient are proposed as evaluation indicators. Taking into account the different sensitivities of different de-icing scenarios to de-icing safety and efficiency, appropriate weight coefficients are determined for different de-icing scenarios based on the analytic hierarchy process. By using linear weighting, the optimal laser power can be quickly selected under the condition that the laser power threshold is determined. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the laser scanning path;

[0041] Figure 2 This is a flowchart of a method for determining road laser de-icing parameters based on power threshold and weight optimization, as described in this invention.

[0042] In the attached diagram, 1 is an asphalt mixture rutting slab specimen, and 2 is the laser scanning path. Detailed Implementation

[0043] 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.

[0044] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0045] The specific implementation methods of the present invention will be described in detail below with reference to the accompanying drawings and embodiments. The present invention aims to fundamentally solve the problem of blind parameter selection in road laser de-icing. Its core idea lies in constructing a closed-loop technical decision-making system. This system begins with adhering to the physical principles of laser-ice interaction, accurately defining the safe and effective power operation boundary through standardized experimental procedures, and ultimately transforming the specific engineering scenario requirements into optimal power parameters using intelligent algorithms. This process achieves a connection between physical theory and engineering practice, ensuring that parameter selection is both scientific and adaptable to the scenario.

[0046] Specific Implementation Method 1: The following is combined with... Figures 1-2This embodiment describes a method for determining road laser de-icing parameters based on power threshold and weight optimization. The method includes the following steps:

[0047] S1. Prepare standardized ice-covered asphalt mixture specimens;

[0048] S2. Determine the scanning path and scanning speed of the laser head based on the specimen size and the de-icing truck's operating mode;

[0049] S3, based on Lambert Beer's Law allows for the preliminary estimation of laser power parameters based on the thickness of the target ice layer;

[0050] S4. Conduct laser de-icing experiments under controlled environmental conditions, and simultaneously monitor the ice layer status and the surface temperature field of the specimen.

[0051] S5. Determine the laser power threshold: The minimum power required when the ice shedding rate at the tilt angle reaches 90% is taken as the minimum effective de-icing power. The maximum safe power is defined as the maximum power achieved when the surface temperature of the specimen reaches 10°C below the asphalt softening point. ;

[0052] S6. Based on the analytic hierarchy process (AHP), determine efficiency weights for different de-icing scenarios. and safety weight ,in And through the formula Calculate the optimal laser de-icing power P.

[0053] The method of this invention constructs a two-stage decision-making model, fundamentally changing the paradigm of parameter selection. The first stage (threshold determination) ensures the basic reliability and security of the solution, avoiding catastrophic failures (invalidity or damage); the second stage (weight optimization) provides flexibility and intelligence in application, enabling the method to cover a variety of needs from emergency de-icing to fine maintenance.

[0054] The optimal power is calculated by weighting safety and efficiency, and safety weight coefficient and efficiency weight coefficient are proposed as evaluation indicators. Taking into account the different sensitivities of different de-icing scenarios to de-icing safety and efficiency, appropriate weight coefficients are determined for different de-icing scenarios based on the analytic hierarchy process. By using linear weighting, the optimal laser power can be quickly selected under the condition that the laser power threshold is determined.

[0055] In step S1, the preparation of icing-covered asphalt mixture specimens specifically includes: according to the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20) (2011) requires the preparation of asphalt mixture rutting slab specimens using the wheel rolling method, with specimen dimensions of length... Width A 50mm thick plate-shaped specimen was used. The required mass of ice was determined by controlling the thickness of the ice layer using the volumetric inverse mass method. First, the rut plate specimen was subjected to low-temperature treatment until the specified temperature was reached. Then, water was sprayed evenly onto the surface of the specimen in small amounts multiple times using a water sprayer until the calculated mass of water required for freezing was consumed, thus completing the freezing treatment of the rut plate specimen.

[0056] The required mass of water is calculated using the volume-to-mass method according to the following formula:

[0057] (1)

[0058] In the formula, The mass of water required for freezing, The density of ice, = , For the target ice thickness, For the area of ​​the specimen, .

[0059] This step is to ensure the reproducibility of the experiment and its representativeness in engineering. The use of standardized rut slab preparation methods ensures that the specimens can simulate the material and structural properties of real road surfaces; the volume-based mass calculation method precisely controls the key variable of ice layer, ensuring consistent ice layer conditions across different experiments and eliminating errors introduced by non-standard specimen preparation.

[0060] This step provides a reliable and standardized data foundation for the entire method. This ensures that the subsequently determined power thresholds are highly reliable and reproducible, enabling a smooth transition from laboratory to engineering applications and resolving the disconnect between laboratory results and field performance.

[0061] In step S2, the scanning path is: controlling the laser head to move along the longitudinal direction of the specimen at a speed Perform uniform linear motion while simultaneously controlling the laser head to move laterally along the specimen at a speed of... Performing high-frequency reciprocating motion causes the laser beam to form a continuous sawtooth scanning trajectory on the surface of the specimen. (See...) Figure 1 As shown.

[0062] This step simulates the operation of a road de-icing vehicle, setting the laser scanning path and controlling the laser head at a speed along the longitudinal direction of the road. Making linear motion, along the transverse direction of the road, in coordination with the laser head vibration device, controlling the laser head's speed. The instrument undergoes reciprocating motion. This study considers the dimensions of the rutted slab specimen and sets the longitudinal velocity accordingly. The lateral velocity is 10 mm / s. At a speed of 60 mm / s, the specimen scanning can be completed after three cycles.

[0063] This step achieves uniform energy distribution through motion synthesis. A single laser beam with concentrated energy can easily cause localized vaporization of the ice layer or burns to the road surface. By combining longitudinal feeding and lateral scanning, the laser beam forms a continuous sawtooth trajectory on the road surface, which is equivalent to dispersing the point energy into a region in a short time. This achieves uniform and rapid heating of the ice layer, which is more conducive to the overall peeling of the ice layer rather than localized penetration.

[0064] It significantly improves the uniformity and efficiency of de-icing, and is a key measure to ensure road safety. It prevents excessive accumulation of laser energy in localized areas, making safety criteria based on the overall road surface temperature more representative and effective.

[0065] Step S3 aims to achieve ice shedding and partial ice melting through laser irradiation. The primary objective is ice shedding. Based on the propagation and action mechanism of laser light within ice, light energy is gradually absorbed as it propagates through the ice, and the laser intensity decreases exponentially with increasing penetration depth. (Based on Lambertian laser technology...) Beer's Law establishes the energy decay model of laser light in ice as follows:

[0066] (2)

[0067] In the formula: This represents the remaining power of the laser when it reaches the ice-road interface. This refers to the incident power of the laser. This represents the absorption coefficient of ice to a specific wavelength of laser light. The target ice thickness;

[0068] For a specific wavelength of laser light, such as a laser with a wavelength of 1064 nm, the absorption coefficient... The value is 23.2 (1 / m). Using the above formula, the remaining power of the laser when it reaches the ice road interface is calculated for different ice thicknesses. Based on this method, the remaining power value when the ice falls off at the tilt angle of the ice layer of that thickness is determined. Then, the appropriate incident laser power range corresponding to different ice thicknesses is determined as the initial laser power.

[0069] This step is based on predictions from a physical model. (Lambert) Beer's Law describes the attenuation of light as it propagates through a medium. This invention utilizes this law to mathematically model the core mechanism of laser de-icing—that laser energy must effectively penetrate the ice layer to reach the interface—thereby calculating the approximate range of suitable incident laser power for different ice thicknesses and preliminarily determining the laser power parameters.

[0070] This approach elevates the initial selection of power from blind guessing to educated estimation. This significantly narrows the search scope for subsequent experiments, improves the overall efficiency of the method, avoids extensive trial and error in invalid power ranges, and saves time and costs.

[0071] In step S4, the process of conducting a laser de-icing experiment under controlled environmental conditions and simultaneously monitoring the ice layer status and road surface temperature field is as follows: The prepared iced asphalt mixture specimen is placed on the experimental platform in a constant temperature and humidity chamber and the temperature is controlled for more than 6 hours to ensure that the temperature of the iced asphalt mixture specimen is consistent with the ambient temperature; the water cooling system and laser are turned on, the parameters are set according to the initial laser power, and the de-icing experiment is carried out using the laser scanning speed and scanning path specified above; the monitoring system is turned on simultaneously, the high-speed camera records the ice layer cracking and melting process, and the infrared thermal imager collects the specimen surface temperature field once per second.

[0072] In step S5, the process of obtaining the tilt angle icing shedding rate D is as follows:

[0073] After the de-icing experiment in step S4 is completed, the laser is turned off, and the angle between the experimental platform and the horizontal plane is slowly adjusted to 45 degrees in the constant temperature and humidity chamber. If the ice layer falls off at this angle, the remaining power value when the ice layer of this thickness falls off at the angle is recorded, and the ice shedding rate D at the angle is calculated according to the following formula:

[0074] (3)

[0075] in, The total mass of the ice layer on the specimen. This represents the total mass of the detached ice layer.

[0076] Then, the infrared images during the experiment were analyzed, and the highest temperature value on the surface of the rutted plate specimen was extracted. When the highest temperature was equal to the softening point temperature of the asphalt used minus 10℃, it was considered to have reached the material damage threshold. The laser power below this temperature was called the safe power.

[0077] (4)

[0078] In the formula: This represents the highest surface temperature of the specimen. This is the softening point of asphalt.

[0079] This step simulates the mechanical effects of actual de-icing and quantifies de-icing efficiency. Ice shedding is not only a result of melting, but also a consequence of the breakdown of the adhesion between the ice and the road surface. Tilting the specimen at a 45-degree angle provides a standardized simulation of the mechanical conditions that cause ice peeling in real-world environments, such as vehicle movement and wind. Using a 90% shedding rate as a threshold is a quantitative engineering standard that balances efficiency and feasibility.

[0080] Here, steps S4 and S5 need to be repeated, using 1% of the laser's maximum output power as the unit adjustment amount, adjusting from small to large. Each adjustment involves repeating steps S4 and S5 to obtain the minimum effective de-icing power that satisfies the de-icing effect. and maximum safe power We approach the theoretical threshold through refined experimental searches. and This is a theoretical critical point, which needs to be confirmed through continuous approximation in actual experiments. Using 1% of the maximum power as a step size is an engineering balance strategy that takes into account both search accuracy and experimental efficiency. It ensures that the final determined power threshold is accurate enough without leading to an excessive number of experiments due to too small a step size. This makes the entire method maintain scientific rigor while possessing good engineering economy.

[0081] Specifically, a laser de-icing experiment was conducted according to predetermined parameters, and temperature changes were monitored in real time. After the experiment, the specimen was tilted at 45 degrees to calculate the ice shedding rate. It was then determined whether the ice shedding rate reached 90%. If it did, the laser power at this point was the minimum effective de-icing power. If the target is not met, adjust the laser power and repeat steps S4 and S5; while judging the ice shedding rate, simultaneously judge whether the maximum temperature value of the specimen surface meets the target. If the conditions are met, the laser power corresponding to that temperature will be used as the maximum safe power. If the conditions are not met, continue to adjust the laser power and repeat steps S4 and S5.

[0082] In step S6, the weight coefficients are determined based on the analytic hierarchy process. and Specifically, it includes:

[0083] S61. Construct a hierarchical model, where the target layer is the parameter weight allocation and the criterion layer includes de-icing efficiency and road safety.

[0084] S62. Construct a judgment matrix A. Experts compare the importance of de-icing efficiency and road safety pairwise for different scenarios, using the classic AHP method. The scaling method is used to score and construct the judgment matrix A:

[0085] (5)

[0086] in, This represents a scale value indicating the importance of de-icing efficiency relative to road safety.

[0087] S63. Weight coefficient calculation: Since the second-order judgment matrix inherently satisfies complete consistency, no consistency check is required. Based on the judgment matrix A, the efficiency weight is calculated using the following formula. and safety weight :

[0088] (6)

[0089] This step objectifies and structures subjective decision-making. The essence of the AHP method lies in transforming people's qualitative judgments about the relative importance of multiple factors into quantitative data through pairwise comparisons and scaling. For the second-order system of this invention, its mathematical essence is to transform expert judgments (scaling values) into quantitative data. It is mapped losslessly to a set of normalized weights.

[0090] This is the core of achieving scenario adaptation. It enables strategic instructions such as prioritizing efficiency or safety to be accurately translated into the mathematical parameters needed to calculate optimal power. , This makes the decision-making process transparent, consistent, and traceable, avoiding the arbitrariness of personal experience.

[0091] In this step, the optimal power is calculated using a weighted allocation of safety and efficiency, and an efficiency weight is proposed. Safety weight reflects the importance of de-icing efficiency. Both reflect the importance of road surface protection and satisfy [the following conditions]. The values ​​range from [0,1]. When At that time, efficiency takes precedence, and optimal power is biased. On one side, when At that time, safety takes precedence, and optimal power is biased. On one side, the formula for calculating the optimal laser power is as follows:

[0092] (7)

[0093] In order to scientifically determine the efficiency weights for different de-icing scenarios and safety weight To achieve precise selection of de-icing laser power, a weighted quantization model based on the analytic hierarchy process (AHP) is proposed.

[0094] The following uses AC Taking 13-graded asphalt concrete as an example, the specific embodiments of the present invention will be described.

[0095] S1. Prepare standardized icing-covered asphalt mixture specimens. According to the requirements of the "Test Procedures for Asphalt and Asphalt Mixtures in Highway Engineering" (JTG E20-2011), prepare asphalt mixture rutting slab specimens using the wheel rolling method. The specimen dimensions are [length missing]. Width A 50mm thick plate-shaped specimen was used. The required mass of ice was determined by controlling the ice layer thickness using the volumetric inverse mass method. First, the rut plate specimen was subjected to low-temperature treatment to ensure it reached the specified temperature. Then, water was sprayed evenly onto the surface of the specimen in small amounts multiple times using a spray bottle until the calculated mass of water required for freezing was consumed. The freezing treatment of the rut plate specimen was then completed. The following are the reference masses corresponding to different ice thicknesses.

[0096]

[0097] S2. Based on the specimen size and the de-icing truck's operating mode, determine the laser head's scanning path and speed. Simulate the road de-icing truck's operation process, set the laser scanning path, and control the laser head's speed along the road's longitudinal direction. Making linear motion, along the transverse direction of the road, in coordination with the laser head vibration device, controlling the laser head's speed. The instrument undergoes reciprocating motion. This study considers the dimensions of the rutted slab specimen and sets the longitudinal velocity accordingly. The lateral velocity is 10 mm / s. At a speed of 60 mm / s, the specimen scanning can be completed after three cycles.

[0098] S3, based on Lambert Beer's Law is used to initially estimate laser power parameters based on the target ice layer thickness. For a laser with a wavelength of 1064 nm, the absorption coefficient is 23.2 (1 / m). Assuming the ambient temperature is obtained from preliminary experiments... When the temperature is ℃, the relative humidity is 50%, and the ice thickness is 10mm, the effective de-icing power is 200W. According to formula (2), the laser power at the interface position is 158.6W. Based on this, it can be deduced that when the ice thickness is 20mm, under the same environmental conditions, the effective de-icing power to achieve the same de-icing effect is about 252.2W. This value is used as the initial laser parameter.

[0099] S4. Laser De-icing Experiment. Place the prepared specimen in the experimental platform of the constant temperature and humidity chamber and maintain the temperature for more than 6 hours to ensure that the specimen temperature is consistent with the ambient temperature. Turn on the water cooling system and laser, set the laser power according to the initial laser power parameters, and conduct the experiment using the laser scanning speed and scanning path specified above. Turn on the monitoring system, use a high-speed camera to record the ice breaking and melting process, and use an infrared thermal imager to collect the surface temperature field of the specimen once per second.

[0100] S5. Determine the laser power threshold. After the experiment, automatically turn off the laser. In the constant temperature and humidity chamber, slowly adjust the angle between the experimental platform and the horizontal plane to 45 degrees to determine whether the ice layer has fallen off. Collect the fallen ice layer and calculate the percentage of the mass of the ice layer that has fallen off. When the percentage of the fallen mass reaches 90%, the de-icing effect is considered to meet the requirements. Power higher than this percentage is called effective de-icing power.

[0101] Then, the infrared images during the experiment were analyzed, and the highest temperature value on the surface of the rutted plate specimen was extracted. When the highest temperature was equal to the softening point temperature of the asphalt used minus 10℃, it was considered to have reached the material damage threshold. The laser power below this temperature was called the safe power.

[0102] S6. Determining the optimal laser de-icing parameters. Repeat S4 and S5, adjusting the laser power by 1% of the laser's maximum output power to obtain the minimum effective de-icing power that satisfies the de-icing effect. and the maximum safe power to reach the material damage threshold .

[0103] Optimal power is calculated by weighting safety and efficiency, and an efficiency weight is proposed. Safety weight reflects the importance of de-icing efficiency. Both reflect the importance of road surface protection and satisfy [the following conditions]. The value range is [0,1]. When At that time, efficiency takes precedence, and optimal power is biased. On one side, when At that time, safety takes precedence, and optimal power is biased. One side.

[0104] The following provides reference values ​​for weighting coefficients in actual road de-icing scenarios. When delayed de-icing leads to serious consequences, efficiency becomes more important. Core scenarios prioritizing efficiency include highways and main roads requiring rapid reopening, as well as emergency traffic management scenarios after heavy snowfall. In these cases, a weighting of efficiency is recommended. The value is 0.8, representing a safety weight. The value is set to 0.2. When road damage repair costs are high and the impact area is large, safety becomes more important. Safety-first scenarios include airport pavements and bridge deck paving, in which case an efficiency weight is recommended. The value is 0.25, representing a safety weight. The value is set to 0.75. The optimal power can be quickly determined using a linear weighted formula, satisfying de-icing efficiency requirements without damaging the road surface, thus balancing practicality and scientific rigor.

[0105] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A method for determining road laser de-icing parameters based on power threshold and weight optimization, characterized in that, The method includes the following steps: S1. Prepare standardized ice-covered asphalt mixture specimens; S2. Determine the scanning path and scanning speed of the laser head based on the specimen size and the de-icing truck's operating mode; S3. Based on the Lambert-Beer law, the laser power parameters are initially estimated according to the thickness of the target ice layer; S4. Conduct laser de-icing experiments under controlled environmental conditions, and simultaneously monitor the ice layer status and the surface temperature field of the specimen. S5. Determine the laser power threshold: The minimum power required when the ice shedding rate at the tilt angle reaches 90% is taken as the minimum effective de-icing power. The maximum safe power is defined as the maximum power achieved when the surface temperature of the specimen reaches 10°C below the asphalt softening point. ; S6. Based on the analytic hierarchy process (AHP), determine efficiency weights for different de-icing scenarios. and safety weight ,in And through the formula Calculate the optimal laser de-icing power P.

2. The method for determining road laser de-icing parameters based on power threshold and weight optimization according to claim 1, characterized in that, In step S1, the preparation of the icing asphalt mixture specimens specifically includes: preparing asphalt mixture rutting slab specimens according to specifications; and using the volumetric back-calculation mass method, based on the target ice layer thickness h and ice density... Given the specimen area S, calculate the required mass of water. The surface of the specimen after low-temperature treatment is evenly sprayed with water until the mass of water consumed is m, thus completing the icing process.

3. The method for determining road laser de-icing parameters based on power threshold and weight optimization according to claim 1, characterized in that, In step S2, the scanning path is: controlling the laser head to move along the longitudinal direction of the specimen at a speed Perform uniform linear motion while simultaneously controlling the laser head to move laterally along the specimen at a speed of... The laser beam performs high-frequency reciprocating motion, causing it to form a continuous sawtooth scanning trajectory on the surface of the specimen.

4. The method for determining road laser de-icing parameters based on power threshold and weight optimization according to claim 1, characterized in that, In step S3, the preliminary estimation of laser power parameters based on Lambert-Beer's law specifically includes: An energy decay model for laser light in ice layers was established based on the Lambert-Beer law: In the formula: This represents the remaining power of the laser when it reaches the ice-road interface. This refers to the incident laser power. The absorption coefficient of ice to a specific wavelength of laser light; The target ice thickness; For a specific wavelength of laser, the remaining power of the laser when it reaches the ice interface is calculated using the above formula for different ice thicknesses. Based on this method, the remaining power value when the ice falls off at the tilt angle of the ice layer of that thickness is determined, and then the appropriate incident laser power range corresponding to different ice thicknesses is determined as the initial laser power.

5. The method for determining road laser de-icing parameters based on power threshold and weight optimization according to claim 4, characterized in that, In step S4, the process of conducting laser de-icing experiments under controlled environmental conditions and simultaneously monitoring the ice layer status and road surface temperature field is as follows: The prepared iced asphalt mixture specimens are placed on the experimental platform in a constant temperature and humidity chamber and the temperature is controlled for more than 6 hours to ensure that the temperature of the iced asphalt mixture specimens is consistent with the ambient temperature; the water cooling system and laser are turned on, the parameters are set according to the initial laser power, and the de-icing experiment is carried out using the laser scanning speed and scanning path specified above; the monitoring system is turned on simultaneously, the high-speed camera records the ice layer cracking and melting process, and the infrared thermal imager collects the specimen surface temperature field once per second.

6. The method for determining road laser de-icing parameters based on power threshold and weight optimization according to claim 5, characterized in that, In step S5, the process of obtaining the tilt angle icing shedding rate D is as follows: After the de-icing experiment in step S4 is completed, the laser is turned off, and the angle between the experimental platform and the horizontal plane is slowly adjusted to 45 degrees in the constant temperature and humidity chamber. If the ice layer falls off at this angle, the remaining power value when the ice layer of this thickness falls off at the angle is recorded, and the ice shedding rate D at the angle is calculated according to the following formula: in, The total mass of the ice layer on the specimen. This represents the total mass of the detached ice layer.

7. The method for determining road laser de-icing parameters based on power threshold and weight optimization according to claim 1, characterized in that, Using 1% of the laser's maximum output power as the unit adjustment amount, repeat steps S4 and S5 to obtain the minimum effective de-icing power that satisfies the de-icing effect. and maximum safe power .

8. The method for determining road laser de-icing parameters based on power threshold and weight optimization according to claim 1, characterized in that, In step S6, the weight coefficients are determined based on the analytic hierarchy process. and Specifically, it includes: S61. Construct a hierarchical model, where the target layer is the parameter weight allocation and the criterion layer includes de-icing efficiency and road safety. S62. Construct a judgment matrix A. Experts compare the importance of de-icing efficiency and road safety pairwise for different scenarios, using the classic AHP method. The scaling method is used to score and construct the judgment matrix A: in, This represents a scale value indicating the importance of de-icing efficiency relative to road safety. S63. Calculation of weighting coefficients: Based on the judgment matrix A, the efficiency weights are calculated using the following formula. and safety weight : 。

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