Virtual road surface generation method and system of discrete impact

Abstract

The invention provides a discrete impact virtual road surface generation method and system, and relates to the technical field of automobile simulation, and the method achieves the forward design of a virtual road surface in an MATLAB environment based on an OpenCRG toolbox, can get rid of the dependence on actual measurement data, and improves the real-time performance of the virtual road surface. A digital road surface containing typical discrete impact characteristics such as a pulse strip, an arc-shaped deceleration strip or a well lid road is directly and flexibly constructed according to automobile smoothness analysis requirements. A regular grid network is constructed by setting pavement geometric parameters and grid resolution, the height of each node is accurately calculated by using a mathematical function, a high-precision pavement height matrix is generated, and finally a standard CRG format file is output. According to the method, the efficiency and controllability of virtual road surface modeling are remarkably improved, accurate reproduction and customized design of discrete impact excitation are achieved, the generated road surface can be directly used for a simulation platform to conduct vehicle smoothness analysis, simulation evaluation on instantaneous impact response is effectively supported, and the method has the technical effects of being easy and convenient to model, high in precision and high in universality.

Description

Technical Field

[0001] This invention relates to the field of automotive simulation technology, and in particular to a method and system for generating virtual road surfaces based on discrete impacts. Background Technology

[0002] As automotive ride comfort demands increase, discrete impacts, as a typical type of discontinuous road surface excitation, significantly affect vehicle ride comfort and component lifespan. Traditional digital road surface modeling relies heavily on collecting actual road surface data in real test tracks using methods such as laser scanning, and then using tools like OpenCRG to generate CRG-formatted virtual road surfaces for simulation analysis. However, this method is highly dependent on ideal acquisition environments and faces challenges such as open traffic interference, adverse weather conditions, and complex terrain limitations, leading to unstable data quality. Furthermore, this process requires expensive equipment, significant manpower, and complex post-processing, resulting in a trade-off between low efficiency, high cost, and difficulty in guaranteeing accuracy. In addition, the massive amount of measured data creates storage and transmission pressures, and it is difficult to flexibly customize specific types of discrete impact features to meet the ride comfort analysis needs under different operating conditions. Summary of the Invention

[0003] The purpose of this invention is to provide a method and system for generating a virtual road surface based on discrete impact, so as to solve the technical problems existing in the prior art and at least provide a beneficial option or create conditions.

[0004] The solution to the technical problem of this invention is as follows: This invention provides a method for generating a virtual road surface based on discrete impact. The method is implemented in the MATLAB environment based on the OpenCRG toolbox and includes the following steps: Load and run the OpenCRG toolbox in MATLAB, and complete the toolbox path configuration and function initialization; Based on the requirements of vehicle ride comfort analysis, the types of discrete impact road surfaces are defined, and the corresponding geometric parameters are defined; the discrete impact road surfaces include pulse strips, curved speed bumps, or manhole cover roads; Define the longitudinal and transverse lengths of the road surface, as well as the longitudinal and transverse intervals, and construct a regular grid node network; Based on the geometric parameters, the height value of each grid node is calculated using mathematical functions to generate a road surface height matrix; The road surface height matrix and mesh parameters are written into a CRG format file to obtain a digital virtual road surface for vehicle ride comfort simulation analysis.

[0005] Furthermore, the discrete impact road surface selects at least one discontinuous obstacle structure, including pulse strips, arc-shaped speed bumps, manhole cover roads or combinations thereof, and randomly distributes them within the longitudinal length through a randomization algorithm, with a distribution density of 1 to 5 obstacles per 100m and a distance of ≥2m between adjacent obstacles.

[0006] Furthermore, the longitudinal interval is dynamically adjusted according to the preset vehicle speed. When the vehicle speed is ≤60km / h, the longitudinal interval is 0.001m. When the vehicle speed is >60km / h, the longitudinal interval increases linearly from 0.001 to 0.005m. The longitudinal length of the road surface is set according to the characteristics of the obstacle.

[0007] Furthermore, the lateral length and lateral spacing support symmetrical or asymmetrical designs. In the case of asymmetry, the obstacle center can deviate from the road centerline by ±0.5m. The lateral spacing is maximized to save memory while ensuring accuracy.

[0008] Furthermore, when the discrete impact road surface is a pulse strip, its geometric parameters include: a rectangular length of 70 to 150 mm, a height of 20 to 30 mm, and a corner radius of 2 to 5 mm; the longitudinal spacing is ≤0.005 m, and the transverse length is ≥4 m to cover the vehicle width.

[0009] Furthermore, when the discrete impact road surface is an arc-shaped speed bump, its geometric parameters include: an arc radius of 0.15 to 0.3m and a height of 30 to 60mm; the longitudinal interval is ≤0.005m and the transverse length is ≥4m.

[0010] Furthermore, when the discrete impact pavement is a manhole cover road, its geometric parameters include: the manhole cover diameter is 500 to 800 mm, the depth is -60 to -30 mm; the longitudinal interval is ≤0.005 m, the transverse interval is ≤0.005 m, and the transverse length is ≥4 m.

[0011] Furthermore, the contours of pulse bars, arc-shaped speed bumps, or manhole cover roads are mathematically modeled by setting piecewise functions or analytical expressions, and the height of each node is calculated accordingly.

[0012] Furthermore, the CRG format file is imported into the ADAMS or MATLAB simulation platform for ride comfort analysis and load decomposition of the vehicle under discrete impact conditions.

[0013] On the other hand, this application provides a virtual road surface generation system for discrete impact, used to execute the aforementioned virtual road surface generation method for discrete impact. The system provides a graphical user interface for setting parameters, previewing effects, and generating reports. The user interface includes an obstacle type selection unit, a parameter input unit, a three-dimensional shape visualization unit, and a simulation file output unit. In the obstacle type selection unit, the user can select at least one discrete impact obstacle structure through a drop-down menu or icon. The structure is selected from pulse bars, arc-shaped speed bumps, or manhole cover roads, and supports the combination configuration of multiple types of obstacles. The parameter input unit provides a differentiated parameter setting interface for the selected obstacle type: For pulse bars, users can set the vertical interval, horizontal interval, rounded corner radius of the rounded rectangle, rectangle length, and height through input boxes; For curved speed bumps, users can set the radius, height, and longitudinal length of the curve using a slider or input box. The longitudinal length is automatically calculated based on the radius and height of the curve. For manhole cover roads, users can set the diameter, indentation height, and lateral spacing through numerical input boxes; In the three-dimensional topography visualization unit, a three-dimensional mesh model of discrete impact road surface is generated and rendered in real time. It supports scaling, rotation and section cutting operations, and can display the local details of each obstacle separately and annotate key dimension parameters. In the simulation file output unit, after the user selects the target simulation tool, the system automatically converts the parameters into an OpenCRG format file and generates a configuration report containing obstacle type, size parameters, mesh accuracy, and file memory usage, supporting export in multiple formats.

[0014] The beneficial effects of this invention are as follows: This application provides a method for generating virtual road surfaces based on discrete impacts. This method achieves forward design of virtual road surfaces in the MATLAB environment based on the OpenCRG toolbox, eliminating the dependence on measured data and directly and flexibly constructing digital road surfaces containing typical discrete impact features such as pulse strips, curved speed bumps, or manhole cover roads according to the needs of vehicle ride comfort analysis. By setting road surface geometric parameters and grid resolution, a regular grid network is constructed, and the height of each node is accurately calculated using mathematical functions to generate a high-precision road surface height matrix, finally outputting a standard CRG format file. This method significantly improves the efficiency and controllability of virtual road surface modeling, realizes accurate reproduction and customized design of discrete impact excitations, and the generated road surface can be directly used for vehicle ride comfort analysis on simulation platforms such as ADAMS and MATLAB, effectively supporting the simulation evaluation of instantaneous impact response. It has the technical effects of simple modeling, high accuracy, and strong versatility. This application also provides a corresponding system, the beneficial effects of which are the same as those of the above method, and will not be elaborated here.

[0015] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings. Attached Figure Description

[0016] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the technical solutions of the present invention, and do not constitute a limitation on the technical solutions of the present invention.

[0017] Figure 1 This is a flowchart of the discrete impact virtual road surface generation method provided in this application; Figure 2 This is a structural diagram of the interactive interface provided in this application. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0019] The present application will be further described below with reference to the accompanying drawings and specific embodiments. The described embodiments should not be considered as limitations on the present application, and all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of the present application.

[0020] In the following description, references are made to “some embodiments,” which describe a subset of all possible embodiments. However, it is understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.

[0022] With the rapid development of the modern automotive industry, consumers' demands for driving comfort are constantly increasing. Vehicle ride comfort, as an important performance indicator for measuring overall vehicle quality, has become one of the core focuses of OEMs during the R&D process. Ride comfort not only affects the subjective experience of drivers and passengers but also directly relates to the fatigue life and reliability of key components such as the vehicle's suspension system, body structure, and seating system. In actual driving, vehicles encounter various types of road surface excitations. One typical and significant type of excitation is "discrete impacts," which refers to the sudden encounter of discontinuous, localized road obstacles such as speed bumps, manhole cover edges, potholes, protruding stones, and construction joints. These obstacles are characterized by sparse spatial distribution, concentrated excitation intensity, and short duration. They can cause severe compression of the suspension system, significant body roll, and a noticeable vertical acceleration impact for occupants within a short period of time, which is fundamentally different from the continuous periodic vibrations of washboard roads or Belgian roads.

[0023] Virtual simulation technology is widely used to accurately assess the dynamic response and comfort performance of vehicles under discrete impact conditions in the early stages of product development. Constructing a high-fidelity digital virtual road surface model is a prerequisite for accurate simulation analysis. Currently, mainstream digital road surface modeling methods in the industry mainly rely on measured data-driven approaches, especially road surface modeling workflows based on the OpenCRG (Open Curved Regular Grid) toolkit. OpenCRG is an open-source toolkit developed by the German Aerospace Center (DLR) that can generate 3D road surface models conforming to the CRG (Curved Regular Grid) format in environments such as MATLAB. It is widely used in multibody dynamics and control system simulation platforms such as ADAMS, CarSim, and MATLAB / Simulink.

[0024] Currently, the construction of digital virtual road surfaces mainly relies on measured data-driven methods. This involves using high-precision laser scanners or 3D profilometers to perform three-dimensional scanning of the real road surface in test fields or actual roads to obtain point cloud data of the road surface's micro-morphology. Subsequently, the raw data undergoes post-processing such as denoising, filtering, coordinate alignment, and interpolation to convert it into a regular raster format. Finally, toolboxes such as OpenCRG are used to generate standard CRG (Curved Regular Grid) format files from the processed height data for vehicle ride comfort analysis in simulation platforms such as ADAMS and MATLAB.

[0025] However, this method is highly dependent on an ideal data collection environment that is closed, undisturbed, and in good weather, making it difficult to obtain high-quality data under open traffic or complex conditions. At the same time, the high-precision equipment and professional personnel lead to high costs; the data processing process is complex, time-consuming, and inefficient; the generated file data volume is large, bringing storage and transmission pressure; and the method is reverse modeling, lacking flexibility, unable to customize or modify road features according to analysis needs, making it difficult to achieve parametric design of obstacles, random distribution, or combination of working conditions construction, and the simulation model has low repeatability and standardization, which seriously restricts its rapid iteration and widespread application in the research and development process.

[0026] To address the aforementioned issues, this application provides a method and system for generating virtual road surfaces under discrete impact conditions. Its core lies in eliminating reliance on measured data and enabling customized design and efficient construction of typical discrete impact road surfaces (such as speed bumps, curved speed bumps, and manhole cover roads) through direct parametric modeling in the MATLAB environment. Based on ride comfort analysis requirements, this method pre-sets the geometric parameters of obstacles (such as height, length, curvature, and fillet radius) and the road surface grid resolution. It then uses mathematical functions or piecewise analytical expressions to accurately calculate the height values ​​of regular grid nodes, generating a road surface height matrix, which is automatically exported as a standard CRG format file. It supports the combination and random distribution of single or multiple obstacle types, offering advantages such as high modeling efficiency, controllable accuracy, small file size, strong repeatability, and flexible adjustment. This effectively solves the limitations of traditional measured modeling in terms of cost, efficiency, flexibility, and applicability, providing an efficient and reliable digital excitation input method for ride comfort simulation and load analysis of vehicles under discrete impact conditions.

[0027] First, the method for generating a virtual road surface with discrete impact provided in this application will be described in detail below with reference to the accompanying drawings. The method is implemented in the MATLAB environment based on the OpenCRG toolbox.

[0028] Reference Figure 1 The implementation process of the discrete impact virtual road surface generation method provided in this application embodiment includes, but is not limited to, the following steps.

[0029] Step S110: Load and run the OpenCRG toolbox in MATLAB to complete the toolbox path configuration and function initialization.

[0030] In step S110, by correctly loading the OpenCRG toolbox in the MATLAB environment, it is ensured that all relevant functions and script files are included in MATLAB's search path. This allows subsequent programs to call the core functional modules provided by the toolbox, such as pavement data structure definition, mesh generation, height field calculation, and CRG file writing. Performing initialization operations (such as running initialization scripts like crg_init.m) verifies the integrity of the toolbox installation, establishes runtime environment dependencies, and prevents program interruptions due to path errors or missing functions. This step ensures the stable operation of the entire generation process, providing a reliable technical support platform for subsequent parameter settings and pavement modeling.

[0031] Step S120: Based on the requirements of vehicle ride comfort analysis, set the type of discrete impact road surface and define the corresponding geometric parameters.

[0032] Discrete impact pavements include pulse strips, curved speed bumps, or manhole cover pavements.

[0033] In step S120, the user selects one or more typical discrete impact structures based on the simulation target, such as "pulse strips" to simulate curbs or construction protrusions, "arc-shaped speed bumps" to characterize traffic deceleration facilities, or "manhole cover roads" to reproduce common recessed obstacles in urban roads. For the selected type, key geometric parameters are further set, such as the rectangular length and corner radius of the pulse strip, the radius of curvature and height of the arc-shaped speed bump, and the diameter and recess depth of the manhole cover road. These parameters directly determine the spatial morphology and excitation intensity of the obstacle, and are a prerequisite for targeted smoothness analysis, ensuring that the generated virtual road surface can realistically reflect the physical characteristics of the target working condition.

[0034] Step S130: Set the longitudinal and transverse lengths of the road surface, as well as the longitudinal and transverse intervals, to construct a regular grid node network.

[0035] In step S130, a spatial discretization framework for the virtual road surface is established. By setting the longitudinal length (L) and lateral length (W) of the road surface, the coverage area of ​​the entire simulated road surface is determined, ensuring that it is sufficient to accommodate the designed obstacles and meet the requirements of vehicle travel trajectories. The longitudinal spacing (uinc) and lateral spacing (vinc) define the resolution of the grid, i.e., the distance between adjacent data points along the vehicle travel direction and vehicle width direction. This parameter directly affects the geometric fidelity of the road surface model and the accuracy of simulation calculations. Based on the above four parameters, the system constructs a regular two-dimensional grid node network as the carrier for subsequent height assignment, forming the basic topology of the digital road surface.

[0036] Step S140: Based on the geometric parameters, calculate the height value of each grid node using mathematical functions to generate the road surface height matrix.

[0037] In step S140, based on the constructed regular grid network, and according to the discrete impact type and its geometric parameters defined in step S120, the road surface height value at each grid node is calculated point by point using corresponding mathematical functions or analytical expressions (such as piecewise functions, circular arc equations, rectangular with rounded corner contour functions, etc.). For example, for an arc-shaped speed bump, the height distribution of its raised contour is calculated using the circular arc equation; for a manhole cover road, a negative height value is assigned within the circular area to form a depression. The set of height values ​​of all nodes constitutes a two-dimensional matrix, namely the road surface height matrix, which completely describes the three-dimensional micromorphology of the entire virtual road surface.

[0038] Step S150: Write the road surface height matrix and mesh parameters into a CRG format file to obtain a digital virtual road surface for vehicle ride comfort simulation analysis.

[0039] In step S150, the final output and format encapsulation of the virtual road surface model are completed. The system calls the file writing function in the OpenCRG toolbox to organize and store the road surface height matrix generated in step S140, along with the grid parameters such as longitudinal length, transverse length, longitudinal spacing, and transverse spacing set in step S130, according to the standard data structure of CRG files, generating a compliant .crg format file. This file contains complete road surface geometry information and can be directly read and called by mainstream vehicle dynamics simulation software such as ADAMS and MATLAB / Simulink. It can be used as input excitation for the vehicle model to carry out ride comfort simulation analysis under discrete impact conditions, thereby realizing a complete closed loop from parameter design to simulation application.

[0040] In some embodiments of this application, the discrete impact road surface selects at least one discontinuous obstacle structure, including pulse strips, arc-shaped speed bumps, manhole cover roads or combinations thereof, and randomly distributes them within the longitudinal length using a randomization algorithm, with a distribution density of 1 to 5 obstacles per 100m and a distance of ≥2m between adjacent obstacles.

[0041] In reality, speed bumps, manhole covers, or road protrusions often appear irregularly, and multiple types may coexist. Therefore, supporting the configuration of single or multiple obstacle types significantly enhances the coverage of virtual road conditions and the representativeness of the simulation. By introducing a randomized algorithm to control the position of obstacles, the resonance artifacts caused by idealized periodic arrangements are avoided, making the dynamic response of vehicles under unpredictable impact sequences closer to real driving scenarios, thus improving the realism and reliability of ride comfort assessment.

[0042] Furthermore, setting the distribution density to 1 to 5 obstacles per 100 meters is based on engineering experience regarding the frequency of typical obstacles in urban and suburban roads. This approach reflects common impact frequencies while maintaining the inherently "discrete" nature of the system. Simultaneously, limiting the distance between adjacent obstacles to at least 2 meters ensures sufficient temporal separation between impact events, allowing the suspension system to respond independently to each excitation and accurately capture transient dynamic behavior. This constraint prevents multiple impacts from superimposing into continuous vibrations, ensuring that the excitation type remains within the discrete impact category. This ensures consistency between the simulation conditions and the research objectives, providing scientific and reasonable testing conditions for the comprehensive comfort analysis of vehicles under complex random impacts.

[0043] In some embodiments of this application, the longitudinal spacing is dynamically adjusted according to a preset vehicle speed. When the vehicle speed is ≤60km / h, the longitudinal spacing is 0.001m. When the vehicle speed is >60km / h, the longitudinal spacing increases linearly from 0.001 to 0.005m. The longitudinal length of the road surface is set according to the characteristics of the obstacle.

[0044] Specifically, when the vehicle speed is ≤60km / h, a high-resolution longitudinal interval of 0.001m is used to accurately capture the changes in road surface contours when passing through discrete impacts (such as speed bumps and manhole cover edges) at low speeds. This ensures the integrity of the excitation waveform and meets the requirement for detailed reproduction of the slow response process of the suspension system, thereby obtaining high-fidelity comfort simulation results. This setting is applicable to typical low-speed conditions such as urban roads, ensuring the accurate representation of key excitation features.

[0045] When the vehicle speed exceeds 60 km / h, the longitudinal spacing increases linearly with speed within the range of 0.001 m to 0.005 m. This is because at high speeds, the vehicle covers a longer distance on the road surface per unit time. Excessively high resolution would lead to a surge in data volume, increasing storage and computational burdens, and the suspension system's response capability to extremely high-frequency excitations is limited. Appropriately relaxing the spacing can avoid redundancy while meeting the characterization requirements of the main excitation frequency bands, thus improving modeling and simulation efficiency. Simultaneously, the longitudinal length of the road surface is reasonably set based on the geometric characteristics of the obstacle (such as length and diameter) to ensure complete inclusion of the target structure and sufficient transition sections, guaranteeing that the vehicle can enter and leave the obstacle area in a stable state, meeting the initial simulation conditions and steady-state analysis requirements, and ensuring the integrity of the excitation input and the reliability of the simulation results.

[0046] In some embodiments of this application, the lateral length and lateral spacing support symmetrical or asymmetrical designs. In the case of asymmetry, the obstacle center can be deviated from the road centerline by ±0.5m. The lateral spacing is maximized to save memory while ensuring accuracy.

[0047] Specifically, the lateral length and spacing support both symmetrical and asymmetrical designs, enhancing the spatial flexibility of the virtual road surface and its coverage of real-world conditions. Symmetrical design is suitable for standard scenarios with obstacles centrally located, meeting the needs of routine ride comfort analysis. Asymmetrical design, on the other hand, allows the obstacle center to deviate from the road centerline by ±0.5m. This range is determined based on typical lane widths and vehicle wheelbases, realistically simulating common off-center obstacle distributions in real roads, such as manhole cover offsets and curb protrusions. This design enables the simulation to accurately reproduce the condition of a single wheel being impacted independently, effectively supporting the analysis of asymmetrical dynamic responses such as vehicle yaw and roll, thus enhancing the real-world representativeness and engineering application value of the simulation results.

[0048] Meanwhile, the lateral spacing is maximized while maintaining the accuracy of the road surface contour representation to optimize the data structure and reduce the number of lateral nodes, thereby significantly reducing the data volume of the road height matrix and the memory footprint of the CRG file. Since discrete impact structures typically exhibit symmetrical or gently varying characteristics in the lateral direction, geometric fidelity can be maintained without excessively dense sampling. By reasonably increasing the lateral spacing (e.g., setting it to 3m), modeling and computational efficiency can be improved without affecting simulation accuracy, reducing the data loading burden on the simulation platform. This is particularly suitable for batch simulations, parametric analyses, and real-time simulations requiring high efficiency, achieving a good balance between model precision and computational economy.

[0049] In some embodiments of this application, when the discrete impact pavement is a pulse strip, its geometric parameters include: a rectangular length of 70 to 150 mm, a height of 20 to 30 mm, and a corner radius of 2 to 5 mm. The longitudinal spacing is ≤0.005 m, and the transverse length is ≥4 m to cover the vehicle width.

[0050] These parameters collectively construct a typical short bump model that conforms to the characteristics of actual roads. The rectangular length covers the size range of common obstacles such as construction joints, road repairs, or curb lifts, effectively exciting the transient response of the suspension system without inducing continuous vibration; the height is set between 20 and 30 mm, which is a moderate vertical excitation, sufficient to cause significant vehicle acceleration and occupant impact, suitable for evaluating the sensitive range of vehicle ride comfort performance; while the rounded corner radius of 2 to 5 mm simulates the wear and chamfer characteristics of real road edges, avoiding the non-physical impact peaks caused by ideal right angles, making the tire contact force change smoother, and improving the numerical stability and realism of the simulation process.

[0051] To ensure accurate modeling of the pulse strip profile, a longitudinal interval of ≤0.005m is set to ensure sufficient sampling of the starting edge, top platform, and ending edge of the obstacle in the driving direction, especially achieving high-fidelity reconstruction in the rounded corner transition area, preventing excitation signal distortion due to insufficient sampling. Simultaneously, the lateral length is set to no less than 4m, fully covering the overall width and wheelbase range of typical passenger cars and light commercial vehicles, ensuring that both wheels can accurately pass through the obstacle area during normal driving or slight deviations, avoiding excitation loss or boundary effects. This design ensures the integrity and consistency of the excitation input during simulation, supports the symmetry and difference analysis of the dynamic response of the suspension on both sides of the vehicle, and enhances the engineering applicability and reliability of virtual testing.

[0052] In some embodiments of this application, when the discrete impact road surface is an arc-shaped speed bump, its geometric parameters include: an arc radius of 0.15 to 0.3 m, a height of 30 to 60 mm, a longitudinal spacing of ≤0.005 m, and a transverse length of ≥4 m.

[0053] The radius of curvature determines the slope characteristics of the speed bump. A radius of 0.15m corresponds to a steeper impact profile, capable of inducing strong instantaneous vibrations, while 0.3m creates a relatively gentle transition, suitable for studying the impact of different curvatures on the dynamic response of the suspension. A height of 30 to 60mm represents a moderate to strong vertical excitation level, effectively inducing noticeable body roll and occupant discomfort, meeting the key operating condition requirements of ride comfort testing. By adjusting these two parameters, the impact response characteristics of the vehicle under speed bumps of different intensities and slopes can be systematically evaluated, providing accurate simulation input for suspension tuning, comfort optimization, and structural durability analysis.

[0054] To ensure the geometric accuracy of the curved profile, a longitudinal interval of ≤0.005m is set to ensure high-density sampling of the continuous curved surface in the driving direction. This avoids profile distortion or non-physical step changes due to insufficient resolution, thus accurately reproducing the force transmission process during the contact between the tire and the speed bump. Simultaneously, the lateral length is set to no less than 4m to fully cover the overall width and driving trajectory range of a typical passenger vehicle, ensuring that both left and right wheels can completely pass over the speed bump, avoiding missing excitation or boundary effects. This design not only guarantees the integrity and consistency of the excitation input during simulation but also supports the analysis of asymmetric dynamic behaviors such as differences in suspension response on both sides of the vehicle and changes in vehicle posture, significantly improving the engineering applicability and simulation reliability of the virtual road surface model.

[0055] In some embodiments of this application, when the discrete impact pavement is a manhole cover road, its geometric parameters include: a manhole cover diameter of 500 to 800 mm, a depth of -60 to -30 mm, a longitudinal spacing of ≤0.005 m, a transverse spacing of ≤0.005 m, and a transverse length of ≥4 m.

[0056] The diameter setting covers the typical span of a standard manhole cover, ensuring that one or both vehicle wheels can completely sink into the recessed area. The depth is represented by a negative value to indicate the amount of subsidence below the reference road surface. The range of -30 to -60 mm corresponds to common manhole cover settlement or installation deviations, effectively stimulating the vehicle's suspension travel, temporary tire lift-off, and dynamic responses such as the vehicle's "drop-rebound" motion. This is suitable for evaluating the "feeling of emptiness" in occupant comfort and structural load transfer characteristics. By adjusting the diameter and depth parameters, the impact of recesses of different sizes on vehicle dynamics can be systematically studied, providing accurate simulation data for ride comfort optimization in urban road conditions.

[0057] To ensure high-fidelity reproduction of the circular recessed contour of the manhole cover, both the longitudinal and lateral intervals are set to no more than 0.005m (5mm). This enables high-density sampling of the manhole cover's inlet, bottom, and outlet areas, avoiding contour distortion or non-physical angularity caused by insufficient resolution. This accurately captures the force change process when the tire contacts the edge of the manhole cover, ensuring the continuity and realism of the excitation input. Simultaneously, the lateral length is set to no less than 4m, fully covering the overall width and driving trajectory range of a typical vehicle. This ensures that whether the vehicle is centered or slightly deviated, both wheels can accurately enter the recessed area of ​​the manhole cover. This design not only avoids excitation loss or boundary effects but also supports the analysis of complex conditions such as asymmetric response of dual-side suspension and changes in vehicle posture, significantly improving the applicability and reliability of the virtual road surface model in the simulation of typical urban recessed obstacles.

[0058] In some embodiments of this application, the contours of impact strips, curved speed bumps, or manhole cover roads are mathematically modeled by setting piecewise functions or analytical expressions, and the height of each node is calculated accordingly. This method abandons the traditional reverse modeling approach that relies on measured data, and instead uses precise mathematical descriptions to define the geometric morphology of various discrete impact obstacles. For example, for impact strips, a rectangular contour model with rounded corners can be used, and the height changes of its leading-edge rising segment, top platform segment, and trailing-edge falling segment can be described by piecewise functions; for curved speed bumps, a continuous and smooth raised surface is established using the circular arc equation; for manhole cover roads, a negative height value is assigned within a specified diameter range based on the concavity function of the circular region, and a gentle slope transition is set at the edge. These mathematical models can not only accurately reproduce the spatial shape of obstacles, but also have the characteristics of adjustable parameters, clear form, and high computational efficiency, making the road surface generation process completely controllable and supporting rapid iteration and customized design.

[0059] In some embodiments of this application, CRG format files are imported into ADAMS or MATLAB simulation platforms for ride comfort analysis and load decomposition of vehicles under discrete impact conditions. As a standardized road surface data format, CRG files can be seamlessly read by the multibody dynamics software ADAMS / CAR, driving the vehicle dynamics model under set excitations such as pulse bars, speed bumps, or manhole covers, thereby obtaining key comfort indicators such as vehicle acceleration, suspension travel, and seat transfer function. Simultaneously, in the MATLAB / Simulink environment, this road surface excitation can be used for control strategy simulation (such as active suspension control) or frequency domain analysis. Furthermore, combined with simulation results, load decomposition studies can be conducted to identify the force characteristics and contribution paths of different components under transient impacts, providing data support for structural durability optimization and system matching. This fully demonstrates the high usability and engineering value of the virtual road surface generated in this application in vehicle performance development.

[0060] Secondly, this application provides a virtual road surface generation system for discrete impact, used to execute the aforementioned virtual road surface generation method for discrete impact. The system provides a graphical user interface for parameter setting, effect preview, and report generation. (Refer to...) Figure 2 The interactive interface includes an obstacle type selection unit, a parameter input unit, a 3D topography visualization unit, and a simulation file output unit.

[0061] In the obstacle type selection unit, users can choose at least one discrete impact obstacle structure via a drop-down menu or icon. The structure can be selected from pulse strips, curved speed bumps, or manhole covers, and combinations of multiple obstacle types are supported. This unit provides users with a convenient entry point, enabling them to flexibly select different types of obstacles according to specific simulation requirements, thereby constructing complex virtual road surface models that conform to actual working conditions, enhancing the system's flexibility and applicability.

[0062] The parameter input unit provides a differentiated parameter setting interface for the selected obstacle type: for pulse bars, users can set the vertical interval, horizontal interval, rounded corner radius of the rounded rectangle, rectangle length, and height via input boxes; for curved speed bumps, users can set the arc radius, height, and vertical length via sliders or input boxes, with the vertical length automatically calculated from the arc radius and height, for example... Where L represents the longitudinal length, R represents the radius of the arc, and H represents the height; for manhole cover roads, users set the diameter, indentation height, and lateral spacing through the numerical input boxes. The parameter input unit ensures that users can accurately set the specific geometric features of each obstacle, and by providing detailed parameter control options, users can achieve highly customized road surface designs to meet the needs of different analysis scenarios.

[0063] In the 3D topography visualization unit, a 3D mesh model of discrete impact pavement is generated and rendered in real time. It supports scaling, rotation, and profile cutting operations, and can display the local details of each obstacle individually, along with annotations of key dimensional parameters. This function not only helps users intuitively understand the spatial morphology of the designed virtual pavement, but also allows for interactive checks of the model's integrity and accuracy, ensuring that the final pavement file accurately reflects the expected geometric features, thus enhancing the transparency and controllability of the modeling process.

[0064] In the simulation file output unit, after the user selects the target simulation tool, the system automatically converts the parameters into OpenCRG format files and generates a configuration report containing obstacle types, size parameters, mesh accuracy, and file memory usage, supporting export in multiple formats. This unit simplifies the workflow from model design to simulation application, ensuring that the generated CRG files can be directly read and used by mainstream simulation platforms such as ADAMS and MATLAB. The provided configuration report helps record and verify model parameters, facilitating subsequent data management and result reproduction, thus improving the efficiency and reliability of the entire simulation process.

[0065] In summary, the discrete impact virtual road surface generation method and system provided in this application have the following technical effects.

[0066] This application constructs a parametric modeling workflow based on the OpenCRG toolbox, enabling the forward design and efficient generation of typical discrete impact pavements such as pulse strips, curved speed bumps, and manhole cover roads. This eliminates the reliance on measured data in traditional methods, significantly reducing modeling costs and time. The system uses piecewise functions or analytical expressions to accurately describe the geometric contours of various obstacles. Combined with adjustable mesh resolution and a random distribution algorithm, it ensures a good balance between geometric accuracy, spatial distribution realism, and simulation efficiency for the virtual pavement. By setting reasonable ranges of geometric parameters (e.g., pulse strip length 70–150 mm, speed bump height 30–60 mm, manhole cover diameter 500–800 mm) and sampling intervals (longitudinal ≤0.005 m), it effectively reproduces the actual impact pavement. The excitation characteristics of discrete impacts in roads enhance the engineering representativeness of simulation inputs. The system integrates a graphical user interface, providing functions such as obstacle type selection, differentiated parameter input, real-time visualization of 3D morphology, and standardized file output, enhancing operational convenience and modeling transparency. The generated CRG format files can be seamlessly imported into mainstream simulation platforms such as ADAMS or MATLAB, supporting ride comfort analysis and load decomposition of vehicles under discrete impact conditions, realizing a complete closed loop from parameter design to simulation application. The overall solution has advantages such as high modeling efficiency, strong flexibility, controllable accuracy, good repeatability, and small file size, making it suitable for rapid iterative development of multiple vehicle models and multiple operating conditions, providing efficient and reliable technical support for forward design and virtual verification of vehicle comfort.

[0067] In some alternative embodiments, the functions / operations mentioned in the block diagrams may not occur in the order shown in the operation diagrams. For example, depending on the functions / operations involved, two consecutively shown blocks may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order. Furthermore, the embodiments presented and described in the flowcharts of this application are provided by way of example to provide a more comprehensive understanding of the technology. The disclosed methods are not limited to the operations and logic flows presented herein. Alternative embodiments are contemplated in which the order of various operations is changed and sub-operations described as part of a larger operation are executed independently.

[0068] Furthermore, although this application is described in the context of functional modules, it should be understood that, unless otherwise stated, one or more of the functions and / or features may be integrated into a single physical device and / or software module, or one or more functions and / or features may be implemented in a separate physical device or software module. It is also understood that a detailed discussion of the actual implementation of each module is unnecessary for understanding this application. Rather, given the properties, functions, and internal relationships of the various functional modules in the apparatus disclosed herein, the actual implementation of the module will be understood within the scope of ordinary skill of an engineer. Therefore, those skilled in the art can implement the application set forth in the claims using ordinary skill. It is also understood that the specific concepts disclosed are merely illustrative and are not intended to limit the scope of this application, which is determined by the full scope of the appended claims and their equivalents.

[0069] If a function is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several programs to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0070] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequential list of executable programs for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, a program execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can retrieve and execute a program from or in conjunction with such a program execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can mean any means that can contain, store, communicate, propagate, or transmit a program for use by or in conjunction with a program execution system, apparatus, or device.

[0071] More specific examples (a non-exhaustive list) of computer-readable media include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Additionally, computer-readable media can even be paper or other suitable media on which programs can be printed, for example, by optically scanning the paper or other media, then editing, interpreting, or, if necessary, processing it in a suitable manner to obtain the program electronically, and then storing it in computer memory.

[0072] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable program execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0073] In the foregoing description of this specification, the reference to terms such as "one embodiment / implementation," "another embodiment / implementation," or "certain embodiments / implementations," etc., indicates that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in an embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0074] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

[0075] The above is a detailed description of the preferred embodiments of the present invention. However, the present invention is not limited to the embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of the present invention.

Claims

1. A method for generating a virtual road surface of discrete impacts, characterized in that, The method is implemented in a MATLAB environment based on an OpenCRG toolbox, and comprises the following steps: loading and running the OpenCRG toolbox in MATLAB, completing toolbox path configuration and function function initialization; setting the type of discrete impact road surface according to the requirements of vehicle ride comfort analysis, and defining the corresponding geometric parameters; the discrete impact road surface comprises pulse strips, arc-shaped speed bumps or manhole covers; setting the longitudinal length and transverse length of the road surface, and the longitudinal interval and transverse interval, and constructing a regular grid node network; calculating the height value of each grid node through a mathematical function according to the geometric parameters, and generating a road surface height matrix; writing the road surface height matrix and grid parameters into a CRG format file to obtain a digital virtual road surface for vehicle ride comfort simulation analysis.

2. The method of claim 1, wherein, The discrete impact road surface selects at least one non-continuous obstacle structure, including pulse strips, arc-shaped speed bumps, manhole covers or combinations thereof, and is randomly distributed in the longitudinal length through a randomization algorithm, with a distribution density of 1 to 5 obstacles per 100 m, and an adjacent obstacle spacing ≥ 2 m.

3. The method of claim 1, wherein, The longitudinal interval is dynamically adjusted according to the preset vehicle speed, the longitudinal interval is 0.001 m when the vehicle speed is ≤ 60 km / h, the longitudinal interval linearly increases within 0.001 to 0.005 m when the vehicle speed is > 60 km / h, and the longitudinal length of the road surface is set according to the characteristics of the obstacle.

4. The method of claim 1, wherein, The transverse length and transverse interval support symmetric or asymmetric design, the obstacle center can deviate from the road surface center line ± 0.5 m when asymmetric, and the transverse interval is maximized under the premise of ensuring accuracy to save memory.

5. The method of claim 1, wherein, When the discrete impact road surface is a pulse strip, the geometric parameters include: a rectangular length of 70 to 150 mm, a height of 20 to 30 mm, and a round corner radius of 2 to 5 mm; the longitudinal interval is ≤ 0.005 m, and the transverse length is ≥ 4 m to cover the vehicle width.

6. The method of claim 1, wherein, When the discrete impact road surface is an arc-shaped speed bump, the geometric parameters include: an arc radius of 0.15 to 0.3 m, and a height of 30 to 60 mm; the longitudinal interval is ≤ 0.005 m, and the transverse length is ≥ 4 m.

7. The method of claim 1, wherein, When the discrete impact road surface is a manhole cover road, the geometric parameters include: a manhole cover diameter of 500 to 800 mm, and a depth of -60 to -30 mm; the longitudinal interval is ≤ 0.005 m, the transverse interval is ≤ 0.005 m, and the transverse length is ≥ 4 m.

8. The method of claim 1, wherein, The profiles of the pulse strips, arc-shaped speed bumps or manhole covers are mathematically modeled by setting piecewise functions or analytical expressions, and the node heights are calculated accordingly.

9. The method of claim 1, wherein, The CRG format file is imported into an ADAMS or MATLAB simulation platform for vehicle ride comfort analysis and load decomposition under discrete impact conditions.

10. A virtual road surface generation system of discrete impacts, characterized by, A system for performing the discrete impact virtual road surface generation method as claimed in any one of claims 1 to 9, the system provides a graphical interactive interface for parameter setting, effect preview and report generation; the interactive interface comprises an obstacle type selection unit, a parameter input unit, a three-dimensional topography visualization unit and a simulation file output unit; In the obstacle type selection unit, users select at least one discrete impact obstacle structure from a pulldown menu or icon, the structure is selected from pulse strips, arc-shaped speed bumps, or manhole cover roads, and combination configurations of multiple types of obstacles are supported; In the parameter input unit, a differentiated parameter setting interface is provided for the selected obstacle type: For pulse strips, users set longitudinal intervals, lateral intervals, the corner radius of a rounded rectangle, the length, and the height of the rectangle through input boxes; For arc-shaped speed bumps, users set the arc radius, height, and longitudinal length through a slider or input box, the longitudinal length is automatically calculated from the arc radius and height; For manhole cover roads, users set the diameter, recess height, and lateral interval through numerical input boxes; In the three-dimensional topography visualization unit, a three-dimensional grid model of the discrete impact road surface is generated and rendered in real time, zooming, rotating, and cross-section cutting operations are supported, local details of each obstacle can be displayed separately, and key dimension parameters are labeled; In the simulation file output unit, after users select a target simulation tool, the system automatically converts the parameters into an OpenCRG format file, generates a configuration report containing obstacle types, dimension parameters, grid accuracy, and file memory occupation, and supports multiple format exports.

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