An interactive design method and system for asphalt mixture grading curve

Abstract

The present application relates to the technical field of road engineering material design, and particularly relates to a kind of asphalt mixture gradation curve interactive design method and system.The method comprises: obtaining material gradation and specification parameter, rendering gradation curve chart, responding to the drag instruction of user to sieve hole node, dynamically updating curve based on node association model, the model abstracts node as elastically connected mass point, keeps curve monotonicity by dynamics iteration, and the elastic stiffness of preset key sieve hole is larger, set the curve after dragging as target curve, inversely calculate each material ratio using weighted least square method, make the synthesized gradation approach target curve, satisfy the constraints that ratio is non-negative and total sum is constant, and the weight coefficient of preset key sieve hole is larger, output ratio scheme and synchronously draw synthesized curve.The present application realizes drag interaction gradation design, improves design efficiency and operation intuitiveness, and reduces the dependence on engineer experience.

Description

Technical Field

[0001] This invention relates to the field of road engineering material design technology, and in particular to an interactive design method and system for asphalt mixture gradation curves. Background Technology

[0002] Asphalt mixture is the core material for highway pavement construction, composed of crushed stone, sand, mineral powder, and asphalt of different particle sizes mixed in a specific ratio. The task of gradation design is to determine the proportion of each component so that the composite gradation forms a smooth, continuous curve in the Taylor coordinate system that falls within the specified range, thereby ensuring the pavement's resistance to rutting, cracking, and durability.

[0003] Currently, spreadsheet software is commonly used in engineering for gradation calculations. The basic process involves engineers inputting sieving data for various aggregates, predicting a mix proportion based on experience, calculating the composite gradation, and visually judging the curve shape. If it is unsatisfactory, the values ​​must be manually modified and recalculated, repeating this process. This traditional forward trial-and-error method has the following significant drawbacks: First, it is inefficient, as each adjustment requires manual data modification and recalculation, a cumbersome process. Second, it is not intuitive enough; how the curve changes after modifying the mix proportions depends entirely on the engineer's spatial imagination, lacking real-time visual feedback. Third, it relies heavily on personal experience, making it difficult for novices to quickly master, resulting in inconsistent design quality. Fourth, manual calculations struggle to simultaneously meet multiple constraints such as smoothness, monotonicity, and precise control of key sieve apertures. Although some automatic optimization methods based on mathematical models exist, these methods are mostly black-box calculations, preventing engineers from intervening in the optimization process, hindering exploratory design, and failing to reflect the need for fine-tuning the curve shape based on specific engineering experience. Summary of the Invention

[0004] To overcome the above shortcomings, this invention provides an interactive design method for asphalt mixture gradation curves, aiming to improve the existing technology that cannot obtain the mix proportion in real time by dragging the curve, relies on repeated manual calculations, is inefficient, depends on experience, and is difficult to balance curve smoothness, monotonicity, and key sieve size control.

[0005] In a first aspect, the present invention provides the following technical solution: an interactive design method for asphalt mixture gradation curves, comprising:

[0006] Obtain material gradation and specification parameters, render a gradation curve, wherein the horizontal axis of the gradation curve is a Taylor coordinate of the sieve aperture size, the vertical axis is the percentage of passing rate, and superimpose the upper limit, lower limit and median curves of the specification;

[0007] In response to the user's drag command on the screen hole points on the curve, the curve is dynamically updated based on the node association model. The model abstracts each screen hole node as an elastically connected mass point, and maintains the monotonicity of the curve through dynamic iteration. The elastic stiffness of the preset key screen holes is greater than that of the non-key screen holes.

[0008] Set the dragged curve as the target curve, and use the weighted least squares method to calculate the proportion of each material in reverse, so that the composite gradation curve approaches the target curve, satisfying the constraints of non-negative proportion and constant sum, and the preset key sieve size weight coefficient is larger.

[0009] The calculated material proportioning scheme is output, and the composite gradation curve is simultaneously plotted on the gradation curve diagram.

[0010] Furthermore, the step of dynamically updating the curve based on the node association model includes:

[0011] Assign mass, position, and velocity attributes to each sieve hole node, and establish elastic connections between adjacent nodes;

[0012] When subjected to external forces, the resultant force on each node is calculated according to the dynamic equations, the acceleration is calculated based on the resultant force and mass, the velocity is updated based on the acceleration, the position is updated based on the velocity, and boundary constraints are applied to the position.

[0013] Repeat the iteration until a stable state is reached or the dragging ends.

[0014] Furthermore, the calculation of the resultant force on each node based on the dynamic equations includes:

[0015] Elastic force and damping force between adjacent particles, and external force applied by the user during dragging;

[0016] The damping force is related to the particle velocity and is in the opposite direction.

[0017] Furthermore, the step of maintaining the monotonicity of the curve through dynamic iteration includes:

[0018] After updating the node position in each dynamic iteration, the pass rate values ​​of adjacent nodes are checked sequentially along the horizontal axis.

[0019] If the monotonicity condition is not met, a correction is applied to the node position to maintain the monotonicity of the curve as the sieve aperture size changes.

[0020] Furthermore, the step of using the weighted least squares method to inversely calculate the proportions of each material includes:

[0021] Using the pass rate of the dragged target curve at each sieve opening as the fitting objective, an optimization objective function is established to minimize the weighted deviation between the synthetic gradation and the target gradation.

[0022] Different weighting coefficients are assigned to different sieve openings, with the weighting coefficient of the key sieve openings being higher than that of the non-key sieve openings.

[0023] The preset key sieve apertures refer to several sieve aperture sizes that play a major role in gradation control.

[0024] Furthermore, it also includes an adaptive constraint step: based on the user-selected mixture type, the displacement change limit and the damping parameters of the physical model are automatically adjusted according to the preset mapping relationship. Different mixture types correspond to different constraint strategies.

[0025] Furthermore, during the drag-and-drop process, at least one of the range constraints and specification constraints is checked in real time, and violations are corrected or flagged.

[0026] Furthermore, the step of batch generating multiple curves includes:

[0027] Get the offset parameter set by the user;

[0028] Using the baseline curve as a reference, at least two target curves with different offset directions are automatically generated so that the offset curves are within the specified range, and the offset weight of the preset key screen holes is greater than that of the non-key screen holes during the offset process.

[0029] Perform reverse calculations on each target curve to output multiple sets of corresponding material proportioning schemes.

[0030] Furthermore, the steps for hump detection and correction include: comparing the combined pass rates of adjacent sieve holes in the fine material section; when the pass rate of the smaller sieve hole is greater than that of the larger sieve hole, a hump phenomenon is determined and a prompt is issued.

[0031] Secondly, the present invention provides the following technical solution: an interactive design system for asphalt mixture gradation curves, used to implement the above-mentioned interactive design method for gradation curves, the system comprising:

[0032] The gradation curve rendering module is used to obtain material gradation and specification parameters, and render a gradation curve. The horizontal axis of the gradation curve is a Taylor coordinate of the sieve aperture size, the vertical axis is the percentage of passing rate, and the specification upper limit, lower limit and median curves are superimposed.

[0033] The curve dynamic update module is used to respond to the user's drag command on the screen hole points of the curve and dynamically update the curve based on the node association model. The model abstracts each screen hole node as an elastically connected mass point, maintains the monotonicity of the curve through dynamic iteration, and presets that the elastic stiffness of key screen holes is greater than that of non-key screen holes.

[0034] The ratio inverse calculation module is used to set the dragged curve as the target curve and use the weighted least squares method to inversely calculate the ratio of each material, so that the composite gradation curve approaches the target curve, satisfying the constraints of non-negative ratio and constant sum, and the preset key sieve size weight coefficient is larger.

[0035] The proportioning output display module is used to output the calculated material proportioning scheme and simultaneously plot the composite gradation curve on the gradation curve graph.

[0036] The present invention has the following beneficial effects:

[0037] 1. In this invention, by abstracting the sieve hole nodes as elastically connected mass points and updating the curve iteratively according to dynamics, the system automatically generates a smooth and continuous curve shape when the user drags, and at the same time calculates and outputs the corresponding proportion in reverse. The design time for a single gradation is shortened from tens of minutes in the traditional method to several minutes, and the design efficiency is significantly improved.

[0038] 2. In this invention, the monotonicity is checked and corrected in real time during the dynamic iteration process to ensure that the gradation curve conforms to physical laws. The preset key sieve holes are given greater elastic stiffness and optimization weight, so that the key particle size position is preferentially close to the target curve, taking into account both the overall smoothness of the curve and the accuracy of the key control points in the engineering.

[0039] 3. In this invention, the drag displacement limit and damping parameters are automatically adjusted according to the type of mixture selected by the user, and the range constraint and specification constraint checks are performed in real time during the dragging process. Nodes that exceed the boundary are automatically corrected to the legal range and prompts are given, thus avoiding invalid design and reducing the threshold of operation experience.

[0040] 4. In this invention, multiple alternative target curves with different offset directions are automatically generated based on the reference curve and offset parameters. Multiple sets of proportioning schemes are then calculated and output in reverse, which makes it easier for engineers to compare and select according to material reserves or engineering requirements, thereby improving the adaptability of the design scheme.

[0041] 5. In this invention, by automatically detecting abnormalities in the passing rate of adjacent sieve holes in the fine material section on the synthetic gradation curve, i.e., the hump phenomenon, and issuing a prompt, the user is assisted in adjusting the mix ratio in a timely manner to avoid potential road performance hazards caused by gradation distortion. Attached Figure Description

[0042] Figure 1 This is a flowchart of an interactive design method for asphalt mixture gradation curves proposed in this invention.

[0043] Figure 2 This is a schematic diagram of the interface effect of the drag-and-drop operation proposed in this invention;

[0044] Figure 3 This is a schematic diagram of the physical mass-spring model proposed in this invention;

[0045] Figure 4 This is a schematic diagram of the multi-point collaborative dragging effect proposed in this invention;

[0046] Figure 5 This is a flowchart illustrating the logic of the beam check proposed in this invention.

[0047] Figure 6This is a schematic diagram illustrating the effect of generating the three curves proposed in this invention;

[0048] Figure 7 This is a system architecture diagram of an interactive design system for asphalt mixture gradation curves proposed in this invention. Detailed Implementation

[0049] The technical solutions in 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] Example 1

[0051] In a first embodiment of the present invention, the present invention provides an interactive design method for asphalt mixture gradation curves, such as... Figure 1 As shown, it includes the following steps:

[0052] S100: Obtain material gradation and specification parameters, render gradation curve, the horizontal axis of the gradation curve is the Taylor coordinate of the sieve aperture size, the vertical axis is the percentage of passing rate, and superimpose the upper limit, lower limit and median curves of the specification.

[0053] Specifically, the data acquisition and preprocessing work is carried out. This process includes obtaining the original gradation information of the raw materials and the technical standard parameters of the selected mixture type. This implementation takes AC-13 asphalt mixture as an example. The acquired material data includes the percentage of mass passing through each standard sieve size for aggregates No. 1, No. 2, No. 3, and No. 4. The standard sieve size sequence typically covers values ​​such as 0.075mm, 0.15mm, 0.3mm, 0.6mm, 1.18mm, 2.36mm, 4.75mm, 9.5mm, 13.2mm, and 16mm.

[0054] Based on the user-selected mixture type, the corresponding standard control range is retrieved from a preset database. These standard parameters include the upper and lower limits of the passing rate for each sieve aperture, as well as the median gradation value.

[0055] After data acquisition, a gradation curve is rendered on the front-end interface. To ensure that the gradation distribution conforms to the intuitive requirements of engineering design, the horizontal axis of the gradation curve is projected using Taylor coordinates, and the vertical axis represents the percentage of pass rate.

[0056] During the rendering process, multiple reference curves are simultaneously plotted in the Taylor coordinate system. The upper limit curve is formed by connecting the upper limit points of each sieve aperture sequentially; the lower limit curve is formed by connecting the lower limit points of each sieve aperture sequentially; and the median curve is formed by connecting the average values ​​of the upper and lower limits corresponding to each sieve aperture. Furthermore, the composite gradation is calculated based on the initially set material proportions, and the initial composite gradation curve is plotted.

[0057] The rendered graphs provide a visual benchmark for subsequent interactive adjustments. Engineers can intuitively judge the rationality of the initial gradation design by comparing the relative positions of the synthesized gradation curve with the upper, lower, and median curves of the specifications. If the synthesized gradation curve exceeds the upper or lower limits of the specifications or deviates too much from the median curve, the process proceeds to the subsequent interactive optimization stage.

[0058] By using the power function transformation of the sieve aperture size as the horizontal axis coordinate, the gradation curve is made to have a linear distribution near the maximum density line, which makes it easy to intuitively judge the coarseness tendency of the gradation. At the same time, the upper limit, lower limit and median curves of the specification are plotted and the gradation curve is calculated and synthesized based on the initial ratio, providing a clear visualization benchmark and optimization target for subsequent drag-and-drop interaction.

[0059] S200: Responding to the user's drag command on the screen hole points of the curve, the curve is dynamically updated based on the node association model. The model abstracts each screen hole node as an elastically connected mass point, and maintains the monotonicity of the curve through dynamic iteration. The elastic stiffness of the preset key screen holes is greater than that of the non-key screen holes.

[0060] Furthermore, the step of dynamically updating the curve based on the node association model includes:

[0061] Assign mass, position, and velocity attributes to each sieve hole node, and establish elastic connections between adjacent nodes;

[0062] When subjected to external forces, the resultant force on each node is calculated according to the dynamic equations, the acceleration is calculated based on the resultant force and mass, the velocity is updated based on the acceleration, the position is updated based on the velocity, and boundary constraints are applied to the position.

[0063] Repeat the iteration until a stable state is reached or the dragging ends.

[0064] Specifically, based on the user's dragging action on specific sieve hole nodes in the graphical interface, the gradation curve is deformed and optimized in real time through physical dynamics simulation. For example... Figure 2 As shown, when a user drags a screen hole node, the curve shape changes in real time with the drag position. This process abstracts discrete screen hole points into particles with physical properties and uses the interaction forces between particles to ensure that the curve maintains smoothness and logical rationality during deformation.

[0065] A physical model is established for each sieve aperture node on the gradation curve, assigning it mass, position, and velocity attributes. Let the th sieve aperture node be... Each sieve node is Its state vector includes the current throughput position, movement speed, and mass, as well as the adjacent sieve nodes. and , Establish flexible connections between them. For example... Figure 3 As shown, adjacent particles are connected by virtual springs, forming a particle-spring system.

[0066] Furthermore, the calculation of the resultant force on each node based on the dynamic equations includes:

[0067] Elastic force and damping force between adjacent particles, and external force applied by the user during dragging;

[0068] The damping force is related to the particle velocity and is in the opposite direction.

[0069] Specifically, when a user selects a screen hole node and generates a displacement command via a mouse or touch device, this command is converted into an external force acting on that node. At each simulation time step... Inside, the resultant force on the node acceleration ,speed ,Location Iterative updates are performed using the following formula:

[0070] ;

[0071] ;

[0072] ;

[0073] ;

[0074] ;

[0075] in, The spring force applied to adjacent particles; For damping force, This is the damping coefficient, ranging from 0.75 to 0.95, which is adaptively adjusted according to the type of mixture. The external force applied by the user to drag; For point mass, it can be uniformly set to 1.0; This represents the iteration time step, typically 0.02-0.05 seconds. The function restricts the position to the range of 0%-100%.

[0076] The calculation of elastic force follows Hooke's law, used to transmit the effects of deformation and maintain the smoothness of the curve. Spring force. The calculation is as follows:

[0077] ;

[0078] in, is the spring stiffness coefficient; for the mass points corresponding to the three key sieve openings of 4.75mm, 2.36mm, and 0.075mm, its The value is set to the corresponding mass point of other sieve holes. Two to three times the value.

[0079] In the physical mass-spring model of this embodiment, the elastic connection between each sieve hole node is regarded as a virtual spring. For non-critical sieve holes, the spring stiffness coefficient is... The preferred value range is 5.0 to 25.0 N / m; for the mass points corresponding to the three key sieve openings of 4.75 mm, 2.36 mm, and 0.075 mm, their... The value is set to 2 to 3 times the value of the non-critical sieve aperture, i.e., the value range is 10.0 to 75.0 N / m. The above values ​​are determined based on the following principle: ensuring that when the user drags a single node, the curve remains within a single iteration step size. System damping coefficient Take a value between 0.1 and 1.0. The displacement increment does not exceed the maximum drag step limit, and the system as a whole is in an overdamped or critically damped state to avoid repeated oscillations during curve dragging and ensure smoothness and stability of interaction.

[0080] After obtaining the resultant force, according to the kinematic equations, this embodiment preferably uses Newton's second law to update the state of each node. After updating the position, boundary constraints are immediately applied to the current throughput position.

[0081] Furthermore, the step of maintaining the monotonicity of the curve through dynamic iteration includes:

[0082] After updating the node position in each dynamic iteration, the pass rate values ​​of adjacent nodes are checked sequentially along the horizontal axis.

[0083] If the monotonicity condition is not met, a correction is applied to the node position to maintain the monotonicity of the curve as the sieve aperture size changes.

[0084] Specifically, to ensure that the asphalt mixture gradation curve conforms to physical laws, i.e., the passing rate must monotonically decrease as the sieve size decreases, this embodiment preferably uses Newton's second law to iteratively update the nodes. After each iteration of updating the node position, a monotonicity check and correction are performed. The check proceeds sequentially along the horizontal axis from the largest sieve aperture to the smallest sieve aperture. If the first... Passing rate of each sieve aperture Less than the throughput of the next smaller sieve aperture If the monotonicity is not satisfied, then a correction command will be applied to the node position. When an adjacent node is detected to violate the monotonicity, the throughput value of the next node will be corrected to the throughput value of the previous node minus a small positive number. Then, the elastic force on the node will be recalculated, so that the adjacent nodes will automatically adjust together through the elastic connection.

[0085] In addition, drag-and-drop operation supports multi-point collaboration mode. For example... Figure 4 As shown, when a node is dragged, adjacent nodes are displaced according to distance weights, achieving multi-point collaboration. When the user drags the first node... There are target points, and the displacement is... At that time, the adjacent first Each point automatically generates a following displacement based on distance weights:

[0086] ;

[0087] ;

[0088] in, The decay exponent is denoted by , and its value is . ; This is the global coordination coefficient, with values ​​ranging from [value missing]. .

[0089] By abstracting the sieve hole nodes as point masses with mass, position, and velocity and establishing elastic connections, user dragging is transformed into external force. The resultant force is calculated iteratively according to Newton's second law, and a velocity-related damping force is set to suppress oscillations. This generates a smooth and continuous curve shape in real time during dragging. By applying boundary constraints to the position and performing monotonicity checks and corrections, the curve is ensured to always satisfy physical laws and graded rationality. Preset key sieve holes are given greater elastic stiffness, enabling them to effectively drive adjacent nodes during dragging, thus strengthening the control over the overall shape of the curve.

[0090] S300: Set the dragged curve as the target curve, use the weighted least squares method to calculate the proportion of each material in reverse, so that the composite gradation curve approaches the target curve, satisfying the constraints of non-negative proportion and constant sum, and the preset key sieve size weight coefficient is larger.

[0091] Furthermore, the step of using the weighted least squares method to inversely calculate the proportions of each material includes:

[0092] Using the pass rate of the dragged target curve at each sieve opening as the fitting objective, an optimization objective function is established to minimize the weighted deviation between the synthetic gradation and the target gradation.

[0093] Different weighting coefficients are assigned to different sieve openings, with the weighting coefficient of the key sieve openings being higher than that of the non-key sieve openings.

[0094] The preset key sieve apertures refer to several sieve aperture sizes that play a major role in gradation control.

[0095] Specifically, the curve stabilized through iterative analysis using Newton's second law is determined as the target gradation curve, and the optimal blending ratio of each raw material is solved in reverse using a mathematical optimization algorithm. An optimization objective function is established, assuming the target gradation curve is within each sieve aperture. The pass rate at that location is The proportions of each raw material grade to be solved are: Construct an objective function based on weighted least squares. The calculation formula is as follows:

[0096] ;

[0097] in, This represents the sum of the weighted sum of squared deviations; This represents the total number of sieve openings involved in the calculation; Indicates the total number of types of raw materials; Indicates the first The weighting coefficient of each sieve hole; Indicates the first The mass ratio of each raw material in the mixture; Indicates the first The first type of raw material in Original passing percentage at each sieve aperture; Indicates the target gradation curve at the th Pass rate at each sieve aperture.

[0098] To ensure that the calculation results meet the actual requirements of the engineering, the system solves the objective function. To find the minimum value, strict linear constraints are introduced, including a non-negativity constraint on the proportions and a constant sum constraint. The constraint equations are as follows: , in This ensures that the sum of the proportions of all materials is 100%, and that the proportion of any single material does not have a negative value.

[0099] In weighting coefficients In terms of allocation, a non-equilibrium allocation strategy is adopted to reflect the differences in the impact of different particle size ranges on the performance of the mixture. The weighting coefficients of preset critical sieve openings are higher than those of non-critical sieve openings. Preset critical sieve openings typically include a 13.2mm nominal maximum particle size sieve, 4.75mm and 2.36mm sieve openings controlling the boundary between coarse and fine aggregates, and a 0.075mm sieve opening controlling the powder content. This is achieved by increasing the weighting coefficients of these nodes. During reverse calculation, priority will be given to ensuring that the composite curve coincides with the target curve at these key positions.

[0100] The system employs the SLSQP (Sequential Least Squares Programming) algorithm to iteratively solve the objective function. The calculated material proportioning scheme is then used. The data is output to memory, and the values ​​of the synthesized gradation curve are updated in real time based on this ratio. At this point, the system will present the final synthesis result while satisfying the principle of minimum weighted deviation.

[0101] By setting the curve formed by user dragging as the target, the weighted least squares method is used to solve the material ratio in reverse, realizing the automatic conversion from the visualized curve to the ratio parameters. The preset key sieve size is given higher weight, so that the synthetic gradation first approaches the target curve at the key particle size position, ensuring the engineering rationality of the ratio scheme. At the same time, the constraints of non-negative ratio and constant sum are introduced to ensure that the solution can be directly used for actual production.

[0102] S400: Output the calculated material proportioning scheme and simultaneously plot the composite gradation curve on the gradation curve diagram.

[0103] Specifically, the generated optimization calculation results are visualized and output as data. The system updates the proportion output module of the front-end interactive interface. The proportion values ​​of each raw material obtained from the reverse calculation are displayed. Enter the corresponding material proportions into the table. These values ​​represent the current optimal material composition scheme.

[0104] Perform the final composite gradation verification calculation to validate the actual performance of the optimized proportioning scheme at each sieve aperture. Utilize the determined proportioning scheme. Compared with the original gradation data of each material The passing rate of the final composite gradation at each sieve aperture is calculated. After obtaining the passing rate values ​​for all sieve apertures, the composite gradation curve is simultaneously plotted on the gradation curve graph. This curve uses Taylor coordinates as the horizontal axis and the passing rate as the vertical axis, connecting each sieve aperture node through spline curves or polylines. At this time, the visualization interface will simultaneously display the upper limit, lower limit, median, and the composite gradation curve generated from the current mix proportion.

[0105] The system automatically verifies the design scheme. It compares the pass rate at each sieve aperture with the preset specification boundary values. If the synthesized gradation curve falls entirely within the envelope formed by the upper and lower limits of the specification, and the curve shape meets the monotonicity requirement, the gradation design is considered effective. The system will display a success message in the interface status bar and allow the user to export the final gradation report.

[0106] By outputting the optimized material proportioning scheme to a proportioning table and recalculating the synthesis gradation curve based on the proportion, and then simultaneously plotting it on a curve graph, a visual closed-loop feedback of the design results is achieved. At the same time, by comparing whether the synthesis pass rate of each sieve hole is within the upper and lower limits of the specification, the design scheme is automatically verified, so that users can intuitively evaluate the effectiveness of the proportion and make timely adjustments.

[0107] Furthermore, it also includes an adaptive constraint step: based on the user-selected mixture type, the displacement change limit and the damping parameters of the physical model are automatically adjusted according to the preset mapping relationship. Different mixture types correspond to different constraint strategies.

[0108] Specifically, during the interactive adjustment of the gradation curve, an adaptive constraint mechanism and a real-time checking algorithm ensure that the design process meets the technical characteristics and specification requirements of the specific mixture. When executing the adaptive constraint step, since different types of asphalt mixtures, such as continuously gradable (AC) and discontinuously gradable (SMA), have different sensitivities to the skeleton structure, the corresponding physical control parameters are extracted from a preset mapping table based on the mixture type selected by the user.

[0109] Furthermore, during the drag-and-drop process, at least one of the range constraints and specification constraints is checked in real time, and violations are corrected or flagged.

[0110] Specifically, range constraint checks and specification constraint checks are performed in real time during the drag-and-drop process. At each time step of the dynamic iteration, the ordinate position of the node is checked. Perform a validity check. For example... Figure 5 As shown, the system sequentially performs range constraint, specification constraint, and monotonicity constraint checks according to the logical flow. If the user attempts to drag a node outside the specification boundary, the system forcibly locks the node's position at the boundary value and issues a violation warning on the interface through a color change, ensuring that the generated auxiliary target curve always remains within the permitted range of the project.

[0111] By automatically adjusting the displacement change limit and damping parameters during the dragging process according to the type of mixture, the interactive control strategy is matched with the gradation sensitivity of different mixtures, which improves the stability and adaptability of curve adjustment. At the same time, range and specification constraint checks are performed in real time during the dragging process, and nodes that exceed the boundary are automatically corrected to the legal range and prompts are given, ensuring that the target curve always meets the requirements of engineering specifications.

[0112] Furthermore, the step of batch generating multiple curves includes:

[0113] Get the offset parameter set by the user;

[0114] Using the baseline curve as a reference, at least two target curves with different offset directions are automatically generated so that the offset curves are within the specified range, and the offset weight of the preset key screen holes is greater than that of the non-key screen holes during the offset process.

[0115] Perform reverse calculations on each target curve to output multiple sets of corresponding material proportioning schemes.

[0116] Specifically, to provide multiple design options, the system supports automatic batch generation of multiple curves based on a baseline curve. It also retrieves user-defined offset parameters. The range of values ​​is Based on the baseline curve of the current design. (The target value can be the standard median or a user-defined target value) as a reference, and generate a group of target curves with different offset directions:

[0117] ;

[0118] ;

[0119] ;

[0120] in, and As a weight vector, critical screen apertures such as 4.75mm, 2.36mm, and 0.075mm have greater weights than non-critical screen apertures; the offset curve values ​​are constrained within the specified upper and lower limits. For example... Figure 6 As shown, based on the standard median value, three target curves—moderate, slightly thin, and slightly coarse—are generated.

[0121] A moderate solution suitable for standard gradation design under normal working conditions; The finer design is suitable for scenarios with higher requirements for anti-slip performance or density; The coarser design is suitable for scenarios with higher requirements for high-temperature resistance to rutting or frame stability.

[0122] By acquiring offset parameters and using the baseline curve as a reference, multiple target curves with different offset directions are automatically generated, and the preset key sieve holes are given greater weight in the offset. At the same time, the offset curves are restricted within the specified range, and multiple sets of proportioning schemes are output in reverse calculation. This allows users to obtain multiple design schemes with different gradation tendencies in a single operation, which is convenient for comparison and selection according to actual needs.

[0123] Furthermore, the steps for hump detection and correction include: comparing the combined pass rates of adjacent sieve holes in the fine material section; when the pass rate of the smaller sieve hole is greater than that of the larger sieve hole, a hump phenomenon is determined and a prompt is issued.

[0124] Specifically, after the synthetic gradation curve is generated, the system performs hump detection and correction using a specialized algorithm. The hump phenomenon usually refers to abnormal fluctuations in the throughput caused by improper gradation of the fine aggregate, which can seriously affect the compaction performance of the mixture.

[0125] The system focuses on monitoring the fine material section, which typically refers to the combined throughput of adjacent sieve openings within a section with a sieve aperture size of 2.36 mm or less. A "hump" phenomenon is confirmed when the throughput of the smaller sieve opening is determined to be greater than that of the larger sieve opening.

[0126] Once a hump is detected, the system will highlight the corresponding section in red on the gradation curve and calculate the minimum correction required to eliminate the hump. The system will then issue a correction prompt to the user, or, with the user's permission, automatically invoke the dynamic model to compensate for the displacement of abnormal nodes, adjusting the material ratio to restore the synthetic curve to a monotonically decreasing smooth shape.

[0127] By comparing the combined passing rates of adjacent sieve openings in the fine aggregate section, the system automatically identifies an abnormal phenomenon where the passing rate of a smaller sieve opening is greater than that of a larger sieve opening. This phenomenon is identified as a "hump" and a warning is issued. This allows for timely detection and alerts to local distortions in the gradation curve, preventing adverse effects on the compaction performance of the mixture due to improper fine aggregate gradation.

[0128] Example 2

[0129] In the mix design scenario of SMA-13 ​​(asphalt mastic macadam) mixtures, engineers need to repeatedly adjust the passing rate of each sieve node on the gradation curve to ensure that the synthesized gradation meets the specification requirements, while ensuring that the curve is smooth and without humps. Because the gradation range of SMA mixtures is narrower than that of AC type, the requirements for mix proportion accuracy are extremely high. Any slight deviation exceeding the specification boundaries may lead to instability of the mixture skeleton structure or insufficient asphalt mastic filling. Traditional trial calculation methods rely on engineers manually modifying mix proportion values ​​and verifying them round by round. This makes it difficult to accurately fall within the narrow gradation window within a limited number of steps, and excessive dragging in a single step can easily cause the curve to exceed the upper and lower limits of the specification, requiring repeated corrections and resulting in low design efficiency.

[0130] Furthermore, the lack of an interactive constraint mechanism for SMA (Small Asphalt Mixture Aperture) profiles prevents engineers from intuitively perceiving the impact of drag-and-drop operations on gradation-sensitive zones. This leads to an over-reliance on personal experience in the design process, making it difficult to guarantee the stability and consistency of the results. To address these issues, this invention provides an interactive design system for asphalt mixture gradation curves, the structure of which is as follows: Figure 7 As shown. The specific implementation process of this system is as follows:

[0131] The gradation curve rendering module acquires material gradation and specification parameters, and renders a gradation curve. The horizontal axis of the gradation curve is a Taylor coordinate of the sieve aperture size, and the vertical axis is the percentage of throughput. It also overlays the upper, lower, and median curves of the specification. The curve dynamic update module responds to user drag commands on the sieve aperture points of the curve and dynamically updates the curve based on a node association model. This model abstracts each sieve aperture node as an elastically connected mass point, maintaining the monotonicity of the curve through dynamic iteration, and pre-setting the elastic stiffness of key sieve apertures to be greater than that of non-key sieve apertures. The proportion inverse calculation module sets the dragged curve as the target curve and uses the weighted least squares method to inversely calculate the proportions of each material, making the synthesized gradation curve approach the target curve, satisfying the constraints of non-negative proportions and a constant sum, and pre-setting a larger weight coefficient for key sieve apertures. The proportion output display module outputs the calculated material proportion scheme and simultaneously plots the synthesized gradation curve on the gradation curve graph.

[0132] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An interactive design method for asphalt mixture gradation curves, characterized in that, include: Obtain material gradation and specification parameters, render a gradation curve, wherein the horizontal axis of the gradation curve is a Taylor coordinate of the sieve aperture size, the vertical axis is the percentage of passing rate, and superimpose the upper limit, lower limit and median curves of the specification; In response to the user's drag command on the screen hole points on the curve, the curve is dynamically updated based on the node association model. The model abstracts each screen hole node as an elastically connected mass point, and maintains the monotonicity of the curve through dynamic iteration. The elastic stiffness of the preset key screen holes is greater than that of the non-key screen holes. Set the dragged curve as the target curve, and use the weighted least squares method to calculate the proportion of each material in reverse, so that the composite gradation curve approaches the target curve, satisfying the constraints of non-negative proportion and constant sum, and the preset key sieve size weight coefficient is larger. The calculated material proportioning scheme is output, and the composite gradation curve is simultaneously plotted on the gradation curve diagram.

2. The interactive design method for asphalt mixture gradation curves according to claim 1, characterized in that, The steps for dynamically updating the curve based on the node association model include: Assign mass, position, and velocity attributes to each sieve hole node, and establish elastic connections between adjacent nodes; When subjected to external forces, the resultant force on each node is calculated according to the dynamic equations, the acceleration is calculated based on the resultant force and mass, the velocity is updated based on the acceleration, the position is updated based on the velocity, and boundary constraints are applied to the position. Repeat the iteration until a stable state is reached or the dragging ends.

3. The interactive design method for asphalt mixture gradation curves according to claim 2, characterized in that, The calculation of the resultant force on each node based on the dynamic equations includes: Elastic force and damping force between adjacent particles, and external force applied by the user during dragging; The damping force is related to the particle velocity and is in the opposite direction.

4. The interactive design method for asphalt mixture gradation curves according to claim 2, characterized in that, The steps for maintaining the monotonicity of the curve through dynamic iteration include: After updating the node position in each dynamic iteration, the pass rate values ​​of adjacent nodes are checked sequentially along the horizontal axis. If the monotonicity condition is not met, a correction is applied to the node position to maintain the monotonicity of the curve as the sieve aperture size changes.

5. The interactive design method for asphalt mixture gradation curves according to claim 1, characterized in that, The steps for calculating the proportions of each material using the weighted least squares method include: Using the pass rate of the dragged target curve at each sieve opening as the fitting objective, an optimization objective function is established to minimize the weighted deviation between the synthetic gradation and the target gradation. Different weighting coefficients are assigned to different sieve openings, with the weighting coefficient of the key sieve openings being higher than that of the non-key sieve openings. The preset key sieve apertures refer to several sieve aperture sizes that play a major role in gradation control.

6. The interactive design method for asphalt mixture gradation curves according to claim 1, characterized in that, It also includes an adaptive constraint step: based on the user-selected mixture type, the displacement change limit and the damping parameters of the physical model are automatically adjusted according to the preset mapping relationship. Different mixture types correspond to different constraint strategies.

7. The interactive design method for asphalt mixture gradation curves according to claim 6, characterized in that, During the drag-and-drop process, at least one of the range constraints and specification constraints is checked in real time, and violations are corrected or flagged.

8. The interactive design method for asphalt mixture gradation curves according to claim 1, characterized in that, This also includes the step of batch generating multiple curves, including: Get the offset parameter set by the user; Using the baseline curve as a reference, at least two target curves with different offset directions are automatically generated so that the offset curves are within the specified range, and the offset weight of the preset key screen holes is greater than that of the non-key screen holes during the offset process. Perform reverse calculations on each target curve to output multiple sets of corresponding material proportioning schemes.

9. The interactive design method for asphalt mixture gradation curves according to claim 1, characterized in that, The process also includes steps for hump detection and correction, such as comparing the combined pass rates of adjacent sieve holes in the fine material section. When the pass rate of the smaller sieve hole is greater than that of the larger sieve hole, a hump phenomenon is determined and a prompt is issued.

10. An interactive design system for asphalt mixture gradation curves, characterized in that, The system for the interactive design method of gradation curves according to any one of claims 1-9 comprises: The gradation curve rendering module is used to obtain material gradation and specification parameters, and render a gradation curve. The horizontal axis of the gradation curve is a Taylor coordinate of the sieve aperture size, the vertical axis is the percentage of passing rate, and the specification upper limit, lower limit and median curves are superimposed. The curve dynamic update module is used to respond to the user's drag command on the screen hole points of the curve and dynamically update the curve based on the node association model. The model abstracts each screen hole node as an elastically connected mass point, maintains the monotonicity of the curve through dynamic iteration, and presets that the elastic stiffness of key screen holes is greater than that of non-key screen holes. The ratio inverse calculation module is used to set the dragged curve as the target curve and use the weighted least squares method to inversely calculate the ratio of each material, so that the composite gradation curve approaches the target curve, satisfying the constraints of non-negative ratio and constant sum, and the preset key sieve size weight coefficient is larger. The proportioning output display module is used to output the calculated material proportioning scheme and simultaneously plot the composite gradation curve on the gradation curve graph.

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