Methods, devices, equipment and media for matching torsional stiffness of new energy off-road vehicles

Abstract

This application relates to the field of vehicle engineering technology, and in particular to a method, device, equipment and medium for matching torsional stiffness of new energy off-road vehicles. The method includes: by establishing a whole vehicle finite element model and a multibody dynamics model, obtaining structural stress, ground load and acceleration peak-to-peak data under different torsional stiffnesses, and combining the vehicle performance requirements to positively determine the target range of torsional stiffness of the body and frame, thereby solving the problems of stiffness redundancy and unreasonable stiffness matching that are easily caused by the benchmarking method in related technologies.

Description

Technical Field

[0001] This application relates to the field of vehicle engineering technology, and in particular to a method, device, equipment and medium for matching torsional stiffness of new energy off-road vehicles. Background Technology

[0002] In the development of new energy off-road vehicles, the relevant technologies usually adopt the industry benchmarking method to determine the torsional stiffness of the body and frame. Using the stiffness of benchmark vehicles as the design basis can easily lead to unreasonable matching of the overall vehicle stiffness, making it difficult to take into account the overall vehicle performance such as passability, durability and ride comfort. Summary of the Invention

[0003] This application provides a method, device, equipment, and medium for matching torsional stiffness of new energy off-road vehicles, in order to solve problems such as stiffness redundancy and unreasonable stiffness matching that are easily caused by the benchmarking method in related technologies.

[0004] The first aspect of this application provides a method for matching the torsional stiffness of a new energy off-road vehicle, comprising the following steps: establishing a whole-vehicle finite element model and a whole-vehicle multibody dynamics model of the new energy off-road vehicle; matching body frame models with different torsional stiffnesses based on the whole-vehicle finite element model, and calculating structural stress data and ground load data under different body frame torsional stiffnesses using the body frame models; matching body frame flexible bodies with different torsional stiffnesses based on the whole-vehicle multibody dynamics model, and calculating peak-to-peak acceleration data under different body frame torsional stiffnesses using the body frame flexible bodies; obtaining the performance requirements of the new energy off-road vehicle, and determining the target range of body torsional stiffness and the target range of frame torsional stiffness based on the performance requirements, structural stress data, ground load data, and peak-to-peak acceleration data.

[0005] Based on the above technical means, this application embodiment establishes a whole vehicle finite element model and a whole vehicle multibody dynamics model of a new energy off-road vehicle to obtain structural stress data, ground load data and acceleration peak-to-peak data under different body and frame torsional stiffness. Then, combined with the vehicle's performance requirements, the target range of body torsional stiffness and frame torsional stiffness is determined. This improves the stiffness redundancy and unreasonable stiffness matching caused by the benchmarking method used in related technologies, making the body and frame stiffness more compatible and improving the vehicle's structural reliability, off-road passability and driving smoothness.

[0006] Optionally, the whole vehicle finite element model includes the body, frame, suspension and powertrain, and the whole vehicle multibody dynamics model includes the body, frame, suspension, powertrain and steering subsystem.

[0007] Based on the above technical means, the embodiments of this application refine and define the components of the two types of simulation models to ensure that the whole vehicle finite element model and the whole vehicle multibody dynamics model fully cover the core components such as the body, frame, and suspension. At the same time, a steering subsystem is added for dynamic simulation needs, which enables the subsequent stress, load and acceleration simulation calculations to fit the actual vehicle conditions, ensuring the accuracy of various simulation data, and thus ensuring the rationality of the subsequent stiffness values.

[0008] Optionally, before matching body and frame models with different torsional stiffness based on the whole vehicle finite element model, the method further includes: setting the body weight and frame weight of the whole vehicle finite element model; applying boundary conditions to the whole vehicle finite element model and performing simulation under the target gravity load; extracting the wheel ground load from the simulation data, calculating the actual deviation between the wheel ground load and the reference ground load, and if the deviation is greater than or equal to the preset deviation, adjusting the body weight and frame weight; otherwise, matching body and frame models with different torsional stiffness based on the whole vehicle finite element model.

[0009] Based on the above technical means, in the embodiments of this application, the counterweight parameters of the model are set and verified before carrying out finite element simulation calculations. The wheel ground load is obtained through gravity load simulation and compared with the reference ground load. After the deviation meets the requirements, subsequent processing is carried out. This can improve the accuracy of the whole vehicle finite element model, make the calculation results of structural stress and ground load more reliable, and provide an accurate data basis for determining the stiffness target range.

[0010] Optionally, before matching flexible body frames with different torsional stiffnesses based on the vehicle multibody dynamics model, the method further includes: setting the assembly mass, center of gravity position, and spring load of the vehicle multibody dynamics model; applying a full-load wheel load to the center of gravity position and calculating the front wheel center displacement and rear wheel center displacement; calculating the displacement difference between the front wheel center displacement and the rear wheel center displacement; if the displacement difference is greater than or equal to a preset difference, adjusting at least one of the assembly mass, center of gravity position, and spring load; otherwise, matching flexible body frames with different torsional stiffnesses based on the vehicle multibody dynamics model.

[0011] Based on the above technical means, before conducting dynamic simulation analysis, the various parameters of the model are first debugged and verified. By applying a full load wheel load to calculate the difference in displacement between the front and rear wheel centers, substandard parameters are adjusted in a timely manner to ensure that the multibody dynamics model fits the actual vehicle state, improve the accuracy of the calculation of peak-to-peak acceleration data, and ensure that the data basis for subsequent stiffness matching work is true and reliable.

[0012] Optionally, based on performance requirements, structural stress data, ground load data, and peak-to-peak acceleration data, the target ranges for the vehicle body torsional stiffness and the frame torsional stiffness are determined. This includes: extracting relevant influence data on vehicle body torsional stiffness and frame torsional stiffness from the structural stress data, ground load data, and peak-to-peak acceleration data, respectively; generating multiple vehicle body torsional stiffness influence curves based on the relevant influence data on vehicle body torsional stiffness; generating multiple frame torsional stiffness influence curves based on the relevant influence data on frame torsional stiffness; and determining the target ranges for the vehicle body torsional stiffness and the frame torsional stiffness based on performance requirements, the multiple vehicle body torsional stiffness influence curves, and the multiple frame torsional stiffness influence curves.

[0013] Based on the above technical means, the embodiments of this application extract the influence data related to the torsional stiffness of the vehicle body and the torsional stiffness of the frame, generate the corresponding stiffness influence curves, and determine the target range of torsional stiffness in combination with vehicle performance requirements. This can make the stiffness value selection process clearer, improve the rationality of the stiffness determination results, and provide a reliable basis for vehicle stiffness design.

[0014] Optionally, multiple body torsional stiffness influence curves are generated based on the body torsional stiffness related influence data, including: extracting the influence data of body torsional stiffness on structural stress, the influence data of body torsional stiffness on ground load, and the influence data of body torsional stiffness on peak-to-peak acceleration from the body torsional stiffness related influence data; generating a first relationship curve based on the influence data of body torsional stiffness on structural stress; generating a second relationship curve based on the influence data of body torsional stiffness on ground load; and generating a third relationship curve based on the influence data of body torsional stiffness on peak-to-peak acceleration.

[0015] Based on the above technical means, the embodiments of this application further refine the specific steps for generating the body torsional stiffness influence curve. By extracting the influence data of body torsional stiffness on structural stress, ground load and acceleration peak value respectively, and generating three relationship curves accordingly, the correlation between body stiffness and key vehicle performance indicators can be intuitively quantified, providing clear data support and analysis basis for accurately determining the target range of body torsional stiffness.

[0016] Optionally, multiple frame torsional stiffness influence curves are generated based on the frame torsional stiffness related influence data, including: extracting the influence data of frame torsional stiffness on structural stress, the influence data of frame torsional stiffness on ground load, and the influence data of frame torsional stiffness on peak-to-peak acceleration from the frame torsional stiffness related influence data; generating a fourth relationship curve based on the influence data of frame torsional stiffness on structural stress; generating a fifth relationship curve based on the influence data of frame torsional stiffness on ground load; and generating a sixth relationship curve based on the influence data of frame torsional stiffness on peak-to-peak acceleration.

[0017] Based on the aforementioned technical means, this application further refines the steps for generating the frame torsional stiffness influence curve. It extracts the influence data of frame torsional stiffness on structural stress, ground load, and peak-to-peak acceleration one by one, generating multiple relationship curves to intuitively reflect the correlation between frame stiffness and various performance indicators. This facilitates the selection of a suitable frame torsional stiffness range based on vehicle performance requirements, ensuring that the stiffness design meets actual usage needs. A second aspect of this application provides a torsional stiffness matching device for a new energy off-road vehicle, comprising: a modeling module for establishing a whole-vehicle finite element model and a whole-vehicle multibody dynamics model of the new energy off-road vehicle; a first calculation module for matching body frame models with different torsional stiffnesses based on the whole-vehicle finite element model, and calculating structural stress data and ground load data under different body frame torsional stiffnesses using the body frame models; a second calculation module for matching body frame flexible bodies with different torsional stiffnesses based on the whole-vehicle multibody dynamics model, and calculating peak-to-peak acceleration data under different body frame torsional stiffnesses using the body frame flexible bodies; and a determination module for obtaining the performance requirements of the new energy off-road vehicle, and determining the target range of body torsional stiffness and the target range of frame torsional stiffness based on the performance requirements, structural stress data, ground load data, and peak-to-peak acceleration data.

[0018] Optionally, the whole vehicle finite element model includes the body, frame, suspension and powertrain, and the whole vehicle multibody dynamics model includes the body, frame, suspension, powertrain and steering subsystem.

[0019] Optionally, it also includes: a first calibration module, used to set the body weight and frame weight of the whole vehicle finite element model before matching body frame models with different torsional stiffness based on the whole vehicle finite element model; after applying boundary conditions to the whole vehicle finite element model, perform simulation under target gravity load; extract the wheel ground load from the simulation data, calculate the actual deviation between the wheel ground load and the reference ground load, and if the deviation is greater than or equal to the preset deviation, adjust the body weight and frame weight; otherwise, match body frame models with different torsional stiffness based on the whole vehicle finite element model.

[0020] Optionally, it also includes: a second calibration module, used to set the assembly mass, center of gravity position, and spring load of the vehicle multibody dynamics model before matching the flexible body frame with different torsional stiffness based on the vehicle multibody dynamics model; apply a full-load wheel load to the center of gravity position and calculate the front wheel center displacement and the rear wheel center displacement; calculate the displacement difference between the front wheel center displacement and the rear wheel center displacement; if the displacement difference is greater than or equal to a preset difference, adjust at least one of the assembly mass, center of gravity position, and spring load; otherwise, match the flexible body frame with different torsional stiffness based on the vehicle multibody dynamics model.

[0021] Optionally, the determining module is further used to: extract the body torsional stiffness-related influence data and the frame torsional stiffness-related influence data from the structural stress data, ground load data, and acceleration peak-to-peak data, respectively; generate multiple body torsional stiffness influence curves based on the body torsional stiffness-related influence data, and generate multiple frame torsional stiffness influence curves based on the frame torsional stiffness-related influence data; and determine the target range of body torsional stiffness and the target range of frame torsional stiffness based on performance requirements, the multiple body torsional stiffness influence curves, and the multiple frame torsional stiffness influence curves.

[0022] Optionally, the determining module is further configured to: extract the influence data of vehicle body torsional stiffness on structural stress, the influence data of vehicle body torsional stiffness on ground load, and the influence data of vehicle body torsional stiffness on peak-to-peak acceleration from the vehicle body torsional stiffness related influence data; generate a first relationship curve based on the influence data of vehicle body torsional stiffness on structural stress; generate a second relationship curve based on the influence data of vehicle body torsional stiffness on ground load; and generate a third relationship curve based on the influence data of vehicle body torsional stiffness on peak-to-peak acceleration.

[0023] Optionally, the determining module is further configured to: extract the influence data of frame torsional stiffness on structural stress, the influence data of frame torsional stiffness on ground load, and the influence data of frame torsional stiffness on peak-to-peak acceleration from the relevant influence data of frame torsional stiffness; generate a fourth relationship curve based on the influence data of frame torsional stiffness on structural stress; generate a fifth relationship curve based on the influence data of frame torsional stiffness on ground load; and generate a sixth relationship curve based on the influence data of frame torsional stiffness on peak-to-peak acceleration.

[0024] A third aspect of this application provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor. The processor executes the program to implement the torsional stiffness matching method for new energy off-road vehicles as described in the above embodiments.

[0025] A fourth aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which is executed by a processor to implement the torsional stiffness matching method for new energy off-road vehicles as described in the above embodiments.

[0026] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0027] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1This is a flowchart of a torsional stiffness matching method for a new energy off-road vehicle according to an embodiment of this application; Figure 2 This is a schematic diagram of the whole vehicle finite element model and part of the counterweight model provided in the embodiments of this application; Figure 3 This is a schematic diagram of the multibody dynamics simulation model of the whole vehicle provided in the embodiments of this application; Figure 4 This is a schematic diagram of the finite element model and boundary conditions of the whole vehicle under gravity load conditions provided in the embodiments of this application; Figure 5 This is a schematic diagram of the simulation calculation model of the torsional stiffness of the vehicle body assembly provided in the embodiments of this application; Figure 6 This is a schematic diagram of the simulation calculation model of the torsional stiffness of the vehicle frame assembly provided in the embodiments of this application; Figure 7 This is a simulation model and boundary condition diagram of the whole vehicle cross axle and large torsion condition provided in the embodiments of this application; Figure 8 This is a graph showing the relationship between structural stress and vehicle body torsional stiffness according to one embodiment of this application; Figure 9 This is a graph showing the relationship between structural stress and frame torsional stiffness, provided in another embodiment of this application. Figure 10 This is a diagram illustrating the effect of frame torsional stiffness on wheel ground load, provided in one embodiment of this application. Figure 11 This is a diagram illustrating the effect of vehicle body torsional stiffness on wheel ground load, provided in another embodiment of this application. Figure 12 This is a diagram illustrating the influence of frame torsional stiffness on the peak-to-peak value of acceleration in the Z direction, provided in one embodiment of this application. Figure 13 This is a diagram showing the influence of vehicle body torsional stiffness on the peak-to-peak value of Z-axis acceleration, provided in another embodiment of this application. Figure 14 This is a flowchart of a torsional stiffness matching method for a new energy off-road vehicle according to an embodiment of this application; Figure 15 This is a block diagram illustrating a torsional stiffness matching device for a new energy off-road vehicle according to an embodiment of this application. Figure 16 This is a schematic diagram of the structure of an electronic device provided according to an embodiment of this application. Detailed Implementation

[0028] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0029] Currently, in the research and development of new energy off-road vehicles, these vehicles typically use a monocoque chassis and a body-on-frame structure. When determining the torsional stiffness targets for the chassis and body assemblies, industry benchmarking is often adopted, generally selecting torsional stiffness values ​​that are at the same level as or higher than those of benchmark vehicles. However, the relevant technologies have the following shortcomings in the design of the torsional stiffness of the body and chassis for new energy off-road vehicles: Firstly, higher body torsional stiffness and frame torsional stiffness are not necessarily better. Simply using benchmark values ​​can easily lead to stiffness redundancy, and under high torsional conditions, it can also affect the ground load of the whole vehicle, thereby reducing the off-road passability of hardcore off-road vehicles. Secondly, there is a matching relationship between body stiffness, frame stiffness and suspension stiffness. Determining the frame and body stiffness targets solely through benchmarking can easily lead to improper stiffness matching, which in turn affects the overall vehicle's durability and ride comfort.

[0030] In summary, the method of determining the torsional stiffness target of the body and frame assembly by relying on industry benchmarking has its shortcomings. The relevant technologies cannot quantify the actual impact of body torsional stiffness and frame torsional stiffness on performance indicators such as torsional angle, durability, ground load, and ride comfort. It is difficult to determine the target range of body and frame torsional stiffness that fits the needs of the vehicle model, and it cannot meet the performance development needs of new energy hardcore off-road vehicles.

[0031] The following description, with reference to the accompanying drawings, outlines a method, apparatus, device, and medium for matching torsional stiffness of new energy off-road vehicles according to embodiments of this application. Addressing the issues of stiffness redundancy and unreasonable stiffness matching that can easily arise from the benchmarking method used in related technologies mentioned in the background, this application provides a method for matching torsional stiffness of new energy off-road vehicles based on finite element simulation combined with multibody dynamics simulation. By quantitatively analyzing the impact of the matching relationship between body torsional stiffness and frame torsional stiffness on performance indicators such as torsional angle, durability, ground load, and ride comfort, the target range of torsional stiffness for the frame and body of hardcore off-road vehicles is positively determined, thereby supporting the project development work of related vehicle models.

[0032] Specifically, Figure 1 This is a flowchart illustrating a torsional stiffness matching method for a new energy off-road vehicle, as provided in an embodiment of this application.

[0033] like Figure 1 As shown, the torsional stiffness matching method for this new energy off-road vehicle includes the following steps: In step S101, a whole vehicle finite element model and a whole vehicle multibody dynamics model of the new energy off-road vehicle are established.

[0034] It is understood that the embodiments of this application establish a whole vehicle finite element model and a whole vehicle multibody dynamics model for new energy off-road vehicles, which can provide a complete model basis for subsequent analysis of the impact of torsional stiffness on various performance indicators, improve the accuracy and reliability of simulation calculations, and provide stable data support for determining the target range of torsional stiffness of the vehicle body and frame.

[0035] Specifically, a finite element model of the entire vehicle was built using Hypermesh (a high-performance finite element preprocessing software). The body assembly, frame assembly, and battery pack were simulated using quadrilateral and triangular plate and shell elements. Suspension components were simulated using beam elements. The body and frame, and the suspension and frame were connected via bushing elements. The battery pack was rigidly connected to the lower wing of the frame using Rbe2 (rigid) elements. Counterweight components were simulated using Mass elements. The complete vehicle finite element model is shown below. Figure 2 As shown; a vehicle multibody dynamics model was built based on Adams_car (vehicle multibody dynamics software), incorporating a flexible body and flexible frame, and simultaneously building front and rear suspension subsystems, front and rear stabilizer bar systems, powertrain subsystems, and steering subsystems. The vehicle multibody dynamics model is as follows. Figure 3 As shown; among them, the simulation calculation model of the torsional stiffness of the vehicle body assembly is as follows: Figure 5 As shown, the simulation calculation model for the torsional stiffness of the chassis assembly is as follows: Figure 6 As shown, it is used for the rapid matching and replacement of body and frame models with different torsional stiffness, and to build a complete simulation model that fits the actual structure of the whole vehicle.

[0036] In this embodiment of the application, the whole vehicle finite element model includes the body, frame, suspension and powertrain, and the whole vehicle multibody dynamics model includes the body, frame, suspension, powertrain and steering subsystem.

[0037] It is understood that the embodiments of this application refine and define the components of the two types of simulation models to ensure that the whole vehicle finite element model and the whole vehicle multibody dynamics model fully cover the core components such as the body, frame, and suspension. At the same time, a steering subsystem is added for the needs of dynamic simulation, which enables the subsequent stress, load and acceleration simulation calculations to fit the actual vehicle conditions, ensuring the accuracy of various simulation data, and thus ensuring the rationality of the subsequent stiffness values.

[0038] Specifically, such as Figure 2 As shown, the finite element model of the whole vehicle additionally includes the battery pack structure, the frame counterweight includes components such as the engine, front and rear motors, and fuel tank, and the body counterweight includes components such as the left and right doors, tailgate, sunroof, hood, occupants, and luggage; such as Figure 3 As shown, the multibody dynamics model of the whole vehicle adds a stabilizing rod system on the basis of the core components, and is matched with a flexible body frame, which takes into account the motion characteristics and structural flexibility characteristics of dynamic simulation, and fully restores the actual assembly and operation structure of the vehicle.

[0039] In step S102, the vehicle body frame model with different torsional stiffness is matched based on the whole vehicle finite element model, and the structural stress data and ground load data under different torsional stiffness of the vehicle body frame are calculated using the vehicle body frame model.

[0040] It is understood that the embodiments of this application are based on the whole vehicle finite element model matched with the body frame model with different torsional stiffness, and the corresponding structural stress data and ground load data are calculated. It is possible to obtain the structural force and wheel load information under different stiffness parameters, and provide data support for subsequent analysis of the influence of body frame stiffness on vehicle structural strength and off-road passability.

[0041] Specifically, five sets of different values ​​for vehicle body torsional stiffness (26000 Nm / °, 22000 Nm / °, 18000 Nm / °, 14000 Nm / °, 10000 Nm / °) and five sets of different values ​​for vehicle frame torsional stiffness (9000 Nm / °, 7500 Nm / °, 6000 Nm / °, 4500 Nm / °, 3000 Nm / °) were selected and combined in pairs to form 25 simulation samples. A 1x gravity load was applied to the entire vehicle, simulating cross-axle and large torsion conditions. The left front wheel contact point's degrees of freedom (DOFs) were constrained and a forced vertical upward displacement was applied. The right rear wheel contact point's degrees of freedom (DOFs) were also constrained and a forced vertical upward displacement was applied. The simulation model is as follows: Figure 7 As shown; the structural Mises stress data and the support reaction force data of the left rear wheel contact point were extracted from each group of samples. A positive support reaction force indicates that the wheel has adhesion when it contacts the ground, while a negative value indicates that the wheel is suspended and has lost adhesion. This characterizes the structural durability and wheel contact load performance. The corresponding structural stress curve is shown in Figure 1. Figure 8 and Figure 9 As shown, the ground load curve is as follows Figure 10 and Figure 11 As shown.

[0042] In this embodiment of the application, before matching body and frame models with different torsional stiffness based on the whole vehicle finite element model, the method further includes: setting the body weight and frame weight of the whole vehicle finite element model; applying boundary conditions to the whole vehicle finite element model and performing simulation under the target gravity load; extracting the wheel ground load from the simulation data, calculating the actual deviation between the wheel ground load and the reference ground load, and if the deviation is greater than or equal to the preset deviation, adjusting the body weight and frame weight; otherwise, matching body and frame models with different torsional stiffness based on the whole vehicle finite element model.

[0043] It is understood that, before conducting finite element simulation calculations, the counterweight parameters of the model are set and verified in this embodiment of the application. The wheel ground load is obtained through gravity load simulation and compared with the reference ground load. Subsequent processing is carried out only after the deviation meets the requirements. This can improve the accuracy of the whole vehicle finite element model, make the calculation results of structural stress and ground load more reliable, and provide an accurate data basis for determining the stiffness target range.

[0044] It should be noted that the target gravity load can refer to the 1x gravity load applied to the finite element model of the whole vehicle, used to simulate the actual load conditions of the vehicle in a stationary state; the actual deviation refers to the difference between the simulated wheel ground load and the full-load design wheel load; the preset deviation refers to the pre-set allowable range of load error, which can be taken as 1% in this embodiment. Only when the actual deviation is less than the preset deviation is the counterweight of the finite element model of the whole vehicle considered to meet the simulation accuracy requirements.

[0045] Specifically, the weight distribution for the chassis assembly and body assembly is achieved using mass elements. The chassis weight distribution covers components such as the front and rear motors, engine, and fuel tank, while the body weight distribution covers components such as doors, tailgate, hood, passenger compartment, and luggage. Boundary constraints are applied at the wheel contact points to conduct a simulation of a 1x gravity load condition. The simulation model is as follows: Figure 4 As shown; the measured wheel ground load is compared with the full-load design wheel load, with a preset deviation threshold of 1%. If the deviation is greater than or equal to 1%, the counterweight is readjusted until the deviation is less than 1% to ensure model accuracy. Figure 4 and Figure 7 Schematic diagrams of boundary conditions for the same finite element model of a vehicle under different operating conditions: Figure 4 Under the condition of 1x gravity load, basic constraints are applied only at the wheel contact points to verify the consistency between the vehicle's weight distribution and the fully loaded design wheel load, ensuring the accuracy of the model's foundation. Figure 7 For cross-axle and large torsion conditions, in addition to the basic constraints, a forced vertical displacement is applied to the contact points of the left front and right rear wheels to simulate extreme off-road torsional deformation and to examine the stress distribution of the vehicle body and frame under large deformation and the wheel contact capability. The two geometric models have the same appearance, but the boundary conditions and load purposes are fundamentally different, corresponding to the simulation analysis needs of different stages.

[0046] In step S103, flexible body frames with different torsional stiffnesses are matched based on the multibody dynamics model of the whole vehicle, and the peak-to-peak acceleration data under different torsional stiffnesses of the body frame are calculated using the flexible body frame frames.

[0047] It is understood that the embodiments of this application match the flexible body frame with different torsional stiffness based on the multibody dynamics model of the whole vehicle, and calculate the corresponding peak-to-peak acceleration data. This can obtain the dynamic response information of the vehicle under different stiffness conditions, and provide data support for subsequent analysis of the impact of body frame stiffness on vehicle ride comfort.

[0048] It should be noted that the peak-to-peak acceleration data refers to the difference between the maximum and minimum peak values ​​of the acceleration signal in the Z-direction (vertical direction) at the driver's seat guide rail position under typical driving conditions such as pulse conditions. It is used to intuitively characterize the vibration and impact intensity and ride comfort of the vehicle during driving. The smaller the peak-to-peak acceleration value, the smaller the vehicle vibration and impact and the better the ride comfort, and vice versa.

[0049] Specifically, 25 sets of simulation samples were formed by pairwise combinations of five pre-selected sets of different body torsional stiffnesses (26000 Nm / °, 22000 Nm / °, 18000 Nm / °, 14000 Nm / °, 10000 Nm / °) and five sets of different frame torsional stiffnesses (9000 Nm / °, 7500 Nm / °, 6000 Nm / °, 4500 Nm / °, 3000 Nm / °). These samples were then matched into the debugged multibody dynamics model to simulate pulse conditions. The peak-to-peak acceleration data in the Z-axis at the driver's seat guide rail position was extracted to characterize the overall vehicle ride comfort and reflect the ride comfort performance under different stiffness matching conditions. The corresponding peak-to-peak acceleration curves are shown below. Figure 12 and Figure 13 As shown.

[0050] In this embodiment of the application, before matching the flexible body frame with different torsional stiffness based on the vehicle multibody dynamics model, the method further includes: setting the assembly mass, center of gravity position, and spring load of the vehicle multibody dynamics model; applying a full-load wheel load to the center of gravity position and calculating the front wheel center displacement and the rear wheel center displacement; calculating the displacement difference between the front wheel center displacement and the rear wheel center displacement; if the displacement difference is greater than or equal to a preset difference, adjusting at least one of the assembly mass, center of gravity position, and spring load; otherwise, matching the flexible body frame with different torsional stiffness based on the vehicle multibody dynamics model.

[0051] It is understandable that, before conducting dynamic simulation analysis, the various parameters of the model are first debugged and verified in this embodiment of the application. The difference in wheel center displacement between the front and rear wheels is calculated by applying a full load, and substandard parameters are adjusted in a timely manner to ensure that the multibody dynamics model fits the actual vehicle condition, improve the accuracy of the peak-to-peak acceleration data, and ensure that the data basis for subsequent stiffness matching work is true and reliable.

[0052] It should be noted that the preset difference value refers to the allowable threshold value of the vertical displacement of the wheel center set in advance to ensure the accuracy of the multibody dynamics model of the whole vehicle. In this embodiment, the value can be 0.1mm. When the difference between the calculated front wheel center displacement and the rear wheel center displacement is less than the preset difference value, it indicates that the unsprung mass, spring preload and assembly state of the model are consistent with the actual vehicle design state, and can meet the accuracy requirements of subsequent dynamics simulation.

[0053] Specifically, the model debugging is divided into two steps. The first step is to adjust the unsprung mass and spring preload: fix the vehicle body and constrain the wheel center, read the vertical support reaction force of the wheel center under the action of natural gravity, and ensure that the deviation from the designed unsprung mass is less than 1%; then remove the wheel center constraint, apply the designed wheel load vertically upward to the wheel center, and preset the displacement threshold to 0.1mm. If the wheel center displacement is greater than or equal to 0.1mm, adjust the spring preload until the displacement is less than 0.1mm; the second step is to input the target values ​​of the vehicle mass, center of gravity, and moment of inertia, and adjust the relevant parameters of the vehicle body to make the vehicle parameters completely consistent with the fully loaded state.

[0054] In step S104, the performance requirements of the new energy off-road vehicle are obtained. Based on the performance requirements, structural stress data, ground load data, and peak-to-peak acceleration data, the target range of the vehicle body torsional stiffness and the target range of the frame torsional stiffness are determined.

[0055] It is understood that, based on the performance requirements of new energy off-road vehicles, this application embodiment comprehensively determines the target range of vehicle body torsional stiffness and frame torsional stiffness by combining structural stress data, ground load data and acceleration peak-to-peak data. This enables the stiffness values ​​to better meet the actual usage requirements of the vehicle, avoids stiffness redundancy or improper stiffness matching, and improves the vehicle's structural reliability, off-road passability and ride comfort.

[0056] It should be noted that the target ranges for body torsional stiffness and frame torsional stiffness refer to the ranges of body and frame torsional stiffness values ​​determined by simulation data and relationship curves, which can simultaneously meet the three major performance requirements of vehicle durability, passability, and ride comfort. Among them, the target range for body torsional stiffness is used to limit the reasonable value of the body's own torsional deformation resistance, and the target range for frame torsional stiffness is used to limit the reasonable value of the frame's own torsional deformation resistance. Together, they constitute the basis for the stiffness matching design of the body and frame of new energy off-road vehicles, ensuring that the vehicle has good ride comfort while meeting the requirements of structural strength and off-road passability.

[0057] Specifically, considering the overall vehicle durability, passability, and ride comfort design requirements: from a durability perspective, the body and frame must withstand n cross-axle cycles without cracking and with Mises stress < Because stiffness and stress are positively correlated, the torsional stiffness of the vehicle body is limited. Frame torsional stiffness From a performance perspective, the wheel contact load under high torsion conditions... Because stiffness is inversely related to ground load, the torsional stiffness of the vehicle body is limited. Frame torsional stiffness From a ride comfort perspective, stiffness and ride comfort are positively correlated, thus limiting the torsional stiffness of the vehicle body. Frame torsional stiffness Taking into account the three performance requirements, the target range for vehicle body torsional stiffness was ultimately determined as follows: Target range for frame torsional stiffness: .

[0058] In this embodiment, the target ranges for vehicle body torsional stiffness and frame torsional stiffness are determined based on performance requirements, structural stress data, ground load data, and peak-to-peak acceleration data. This includes: extracting vehicle body torsional stiffness-related influence data and frame torsional stiffness-related influence data from the structural stress data, ground load data, and peak-to-peak acceleration data, respectively; generating multiple vehicle body torsional stiffness influence curves based on the vehicle body torsional stiffness-related influence data, and generating multiple frame torsional stiffness influence curves based on the frame torsional stiffness-related influence data; and determining the target ranges for vehicle body torsional stiffness and frame torsional stiffness based on performance requirements, the multiple vehicle body torsional stiffness influence curves, and the multiple frame torsional stiffness influence curves.

[0059] It is understood that the embodiments of this application extract the influence data related to the torsional stiffness of the vehicle body and the torsional stiffness of the frame respectively, generate the corresponding stiffness influence curves, and determine the target range of torsional stiffness in combination with vehicle performance requirements. This can make the stiffness value selection process clearer, improve the rationality of the stiffness determination results, and provide a reliable basis for vehicle stiffness design.

[0060] Specifically, the performance data under a single variable is extracted and analyzed. The influence of body stiffness on various performance parameters is analyzed by fixing the frame stiffness, and the influence of frame stiffness on various performance parameters is analyzed by fixing the body stiffness. Based on each set of valid data, the relationship curves between body torsional stiffness and frame torsional stiffness and various performance parameters are plotted respectively to intuitively reflect the change law of stiffness and performance. Then, a reasonable stiffness target range is defined in combination with the vehicle performance indicators.

[0061] In this embodiment of the application, multiple body torsional stiffness influence curves are generated based on the body torsional stiffness related influence data, including: extracting the influence data of body torsional stiffness on structural stress, the influence data of body torsional stiffness on ground load, and the influence data of body torsional stiffness on peak-to-peak acceleration from the body torsional stiffness related influence data; generating a first relationship curve based on the influence data of body torsional stiffness on structural stress; generating a second relationship curve based on the influence data of body torsional stiffness on ground load; and generating a third relationship curve based on the influence data of body torsional stiffness on peak-to-peak acceleration.

[0062] It is understood that the embodiments of this application further refine the specific steps for generating the body torsional stiffness influence curve. By extracting the influence data of body torsional stiffness on structural stress, ground load and acceleration peak value respectively, and generating three relationship curves accordingly, the correlation between body stiffness and key vehicle performance indicators can be intuitively quantified, providing clear data support and analysis basis for accurately determining the target range of body torsional stiffness.

[0063] It should be noted that the first, second, and third relationship curves are all performance change curves obtained by changing only the torsional stiffness of the vehicle body, under the premise that the torsional stiffness of the frame remains constant: the first relationship curve is the corresponding relationship curve between the torsional stiffness of the vehicle body and the structural stress, used to characterize the influence of the torsional stiffness of the vehicle body on the structural durability; the second relationship curve is the corresponding relationship curve between the torsional stiffness of the vehicle body and the wheel ground load, used to characterize the influence of the torsional stiffness of the vehicle body on the off-road passability; the third relationship curve is the corresponding relationship curve between the torsional stiffness of the vehicle body and the peak-to-peak value of the Z-axis acceleration, used to characterize the influence of the torsional stiffness of the vehicle body on the ride comfort.

[0064] Specifically, the first relationship curve reflects the positive relationship between the torsional stiffness of the vehicle body and the structural stress when the frame stiffness is fixed, such as... Figure 8 As shown; the second relationship curve reflects the inverse relationship between the torsional stiffness of the vehicle body and the wheel contact load when the frame stiffness is fixed, such as... Figure 11 As shown; the third relationship curve reflects the inverse relationship between the torsional stiffness of the vehicle body and the peak-to-peak value of the Z-axis acceleration when the frame stiffness is fixed, as shown. Figure 13 As shown, the three curves correspond to the three major performance indicators of durability, passability, and smoothness, respectively.

[0065] In this embodiment of the application, multiple frame torsional stiffness influence curves are generated based on the frame torsional stiffness related influence data, including: extracting the influence data of frame torsional stiffness on structural stress, the influence data of frame torsional stiffness on ground load, and the influence data of frame torsional stiffness on peak-to-peak acceleration from the frame torsional stiffness related influence data; generating a fourth relationship curve based on the influence data of frame torsional stiffness on structural stress; generating a fifth relationship curve based on the influence data of frame torsional stiffness on ground load; and generating a sixth relationship curve based on the influence data of frame torsional stiffness on peak-to-peak acceleration.

[0066] It is understood that the embodiments of this application further refine the steps for generating the frame torsional stiffness influence curve, extracting the influence data of frame torsional stiffness on structural stress, ground load, and peak-to-peak acceleration one by one, and generating multiple relationship curves accordingly, which intuitively reflect the correlation between frame stiffness and various performance indicators, making it easier to select a suitable frame torsional stiffness range in combination with vehicle performance requirements, and ensuring that the stiffness design meets actual use needs.

[0067] It should be noted that the fourth, fifth, and sixth relationship curves are all performance change curves obtained by changing only the frame torsional stiffness under the premise that the body torsional stiffness remains constant: the fourth relationship curve is the corresponding relationship curve between frame torsional stiffness and structural stress, used to characterize the influence of frame torsional stiffness on structural durability; the fifth relationship curve is the corresponding relationship curve between frame torsional stiffness and wheel ground load, used to characterize the influence of frame torsional stiffness on vehicle off-road passability; the sixth relationship curve is the corresponding relationship curve between frame torsional stiffness and peak-to-peak value of Z-axis acceleration, used to characterize the influence of frame torsional stiffness on vehicle ride comfort.

[0068] Specifically, the fourth relationship curve reflects the positive relationship between the frame torsional stiffness and structural stress when the body stiffness is constant, such as... Figure 9 As shown; the fifth relationship curve reflects the inverse relationship between the frame torsional stiffness and the wheel ground load when the vehicle body stiffness is fixed, such as... Figure 10 As shown; the sixth relationship curve reflects the inverse relationship between the frame torsional stiffness and the peak-to-peak value of the Z-axis acceleration when the body stiffness is constant, as shown in the figure. Figure 12 As shown, the six curves fully cover the influence of the body and frame stiffness on various key performance characteristics.

[0069] According to the torsional stiffness matching method for new energy off-road vehicles proposed in this application, by establishing a whole vehicle finite element model and a whole vehicle multibody dynamics model for the new energy off-road vehicle, structural stress data, ground load data, and peak-to-peak acceleration data under different body and frame torsional stiffness are obtained. Then, combined with the vehicle's performance requirements, the target range of body torsional stiffness and frame torsional stiffness is determined. This improves the stiffness redundancy and unreasonable stiffness matching caused by using a benchmarking method to determine stiffness in related technologies, making the body and frame stiffness more compatible, and improving the vehicle's structural reliability, off-road passability, and ride comfort.

[0070] The following section will explain in detail the positive design method for matching the torsional stiffness of the body and frame of a new energy off-road vehicle proposed in this application through a specific embodiment, such as... Figure 14 As shown, the specific steps are as follows: In step one, two types of vehicle simulation models are established. A finite element model and a multibody dynamics model of the new energy off-road vehicle are built respectively: the finite element model is built using HyperMesh software, including the body assembly, frame assembly, suspension system, powertrain, and battery pack; the multibody dynamics model is built using Adams / Car software, including the flexible body, flexible frame, suspension system, powertrain, stabilizer bar, and steering subsystem.

[0071] In step two, the finite element model is calibrated for weight and accuracy. The entire vehicle finite element model is calibrated for weight and accuracy: Mass elements are used to apply weights to the body assembly and frame assembly, covering components such as the engine, motor, fuel tank, doors, occupants, and luggage. Boundary conditions are applied at the wheel contact points, and a simulation of a 1x gravity load is conducted. The simulated wheel contact load is compared with the full-load design wheel load, and the deviation is required to be less than 1%. If the deviation is ≥1%, the weight is readjusted until the accuracy requirements are met.

[0072] In step three, the parameters of the multibody dynamics model are adjusted. The parameters of the vehicle's multibody dynamics model are calibrated: the mass, center of gravity position, moment of inertia, and initial spring preload of each suspension component are checked; the vehicle body is fixed, and a vertically upward full-load wheel load is applied to the wheel centers, requiring the vertical displacement of the front and rear wheel centers to be less than 0.1mm; if the displacement is ≥0.1mm, the spring preload is adjusted until the requirement is met; the target vehicle mass, center of gravity, and moment of inertia are input, and the relevant vehicle body parameters are adjusted to make the vehicle parameters consistent with the full-load state.

[0073] In step four, multiple stiffness matching simulations are performed. Multiple torsional stiffness matching simulations are conducted for both types of models: In the finite element model, multiple body and frame models with different torsional stiffnesses are matched to simulate cross-axle and large torsion conditions, calculating structural stress and wheel ground load under different stiffness combinations; in the multibody dynamics model, multiple flexible body and frame models with different torsional stiffnesses are matched to simulate pulse conditions, calculating the peak-to-peak value of the Z-axis acceleration at the driver's seat guide rail position under different stiffness combinations.

[0074] In step five, comprehensive performance analysis and stiffness range determination are performed. Based on simulation results and combined with vehicle performance requirements, the target range for torsional stiffness of the body and frame is determined: From a durability perspective, the Mises stress of the structure is limited to not exceeding a threshold, resulting in an upper stiffness constraint; from a passability perspective, the wheel ground load is limited to be greater than 0, resulting in an upper stiffness constraint; from a ride comfort perspective, the peak-to-peak value of the Z-axis acceleration is limited to meet driving and riding standards, resulting in a lower stiffness constraint; combining these three types of constraints, the final target range for body torsional stiffness is determined. Target range for frame torsional stiffness: .

[0075] In summary, the embodiments of this application have at least the following beneficial effects: (1) Adopting the joint simulation design approach, HyperMesh whole vehicle finite element simulation and Adams / Car whole vehicle multibody dynamics simulation are combined to conduct analysis around structural durability performance, off-road pass performance and driving smooth performance, forming a positive design scheme for the torsional stiffness of the body and frame, so that the stiffness value is more in line with the actual use scenario of the vehicle.

[0076] (2) By setting counterweights, checking load deviations, and adjusting wheel center displacement, the simulation accuracy of the finite element model and the multibody dynamics model is ensured, the credibility of data such as structural stress, ground load, and peak-to-peak acceleration is improved, and a reliable basis is provided for determining the stiffness range.

[0077] (3) Quantify the relationship between stiffness and performance. Through multiple sets of torsional stiffness matching simulations, clarify the influence of body and frame stiffness on structural stress, wheel ground load and ride comfort index, and draw corresponding relationship curves. This can intuitively define a reasonable range of stiffness values ​​and provide clear guidance for body and frame stiffness design.

[0078] (4) To meet the needs of new energy hardcore off-road vehicles, achieve reasonable matching of body and frame stiffness in complex off-road conditions and daily driving scenarios, improve vehicle structural reliability, off-road capability and driving comfort, and optimize the overall performance of the vehicle.

[0079] Next, referring to the accompanying drawings, the torsional stiffness matching device for new energy off-road vehicles proposed according to the embodiments of this application is described.

[0080] Figure 15 This is a block diagram of a torsional stiffness matching device for new energy off-road vehicles according to an embodiment of this application.

[0081] like Figure 15 As shown, the torsional stiffness matching device 150 for new energy off-road vehicles includes: a setup module 1501, a first calculation module 1502, a second calculation module 1503, and a determination module 1504.

[0082] The system comprises the following modules: Module 1501 is used to establish the whole vehicle finite element model and the whole vehicle multibody dynamics model of the new energy off-road vehicle; Module 1502 is used to match the whole vehicle finite element model with body frame models of different torsional stiffnesses, and to calculate the structural stress data and ground load data under different body frame torsional stiffnesses using the body frame models; Module 1503 is used to match the whole vehicle multibody dynamics model with body frame flexible bodies of different torsional stiffnesses, and to calculate the peak-to-peak acceleration data under different body frame torsional stiffnesses using the body frame flexible bodies; and Module 1504 is used to obtain the performance requirements of the new energy off-road vehicle, and to determine the target range of body torsional stiffness and the target range of frame torsional stiffness based on the performance requirements, structural stress data, ground load data, and peak-to-peak acceleration data.

[0083] In this embodiment of the application, the whole vehicle finite element model includes the body, frame, suspension and powertrain, and the whole vehicle multibody dynamics model includes the body, frame, suspension, powertrain and steering subsystem.

[0084] In this embodiment of the application, the apparatus 150 further includes a first calibration module.

[0085] The first calibration module is used to set the body weight and frame weight of the whole vehicle finite element model before matching body frame models with different torsional stiffness based on the whole vehicle finite element model; after applying boundary conditions to the whole vehicle finite element model, simulation is performed under the target gravity load; the wheel ground load in the simulation data is extracted, and the actual deviation between the wheel ground load and the reference ground load is calculated. If the deviation is greater than or equal to the preset deviation, the body weight and frame weight are adjusted; otherwise, the body frame model with different torsional stiffness is matched based on the whole vehicle finite element model.

[0086] In this embodiment of the application, the apparatus 150 further includes a second calibration module.

[0087] The second calibration module is used to set the assembly mass, center of gravity position, and spring load of the vehicle multibody dynamics model before matching the flexible body frame with different torsional stiffness based on the vehicle multibody dynamics model; apply a full-load wheel load to the center of gravity position and calculate the front wheel center displacement and rear wheel center displacement; calculate the displacement difference between the front wheel center displacement and the rear wheel center displacement; if the displacement difference is greater than or equal to a preset difference, adjust at least one of the assembly mass, center of gravity position, and spring load; otherwise, match the flexible body frame with different torsional stiffness based on the vehicle multibody dynamics model.

[0088] In this embodiment of the application, the determining module 1504 is further configured to: extract the body torsional stiffness-related influence data and the frame torsional stiffness-related influence data from the structural stress data, ground load data, and acceleration peak-to-peak data, respectively; generate multiple body torsional stiffness influence curves based on the body torsional stiffness-related influence data, and generate multiple frame torsional stiffness influence curves based on the frame torsional stiffness-related influence data; and determine the target range of body torsional stiffness and the target range of frame torsional stiffness based on performance requirements, the multiple body torsional stiffness influence curves, and the multiple frame torsional stiffness influence curves.

[0089] In this embodiment of the application, the determining module 1504 is further configured to: extract the influence data of vehicle body torsional stiffness on structural stress, the influence data of vehicle body torsional stiffness on ground load, and the influence data of vehicle body torsional stiffness on peak-to-peak acceleration from the vehicle body torsional stiffness related influence data; generate a first relationship curve based on the influence data of vehicle body torsional stiffness on structural stress; generate a second relationship curve based on the influence data of vehicle body torsional stiffness on ground load; and generate a third relationship curve based on the influence data of vehicle body torsional stiffness on peak-to-peak acceleration.

[0090] In this embodiment of the application, the determining module 1504 is further configured to: extract the influence data of frame torsional stiffness on structural stress, the influence data of frame torsional stiffness on ground load, and the influence data of frame torsional stiffness on peak-to-peak acceleration from the relevant influence data of frame torsional stiffness; generate a fourth relationship curve based on the influence data of frame torsional stiffness on structural stress; generate a fifth relationship curve based on the influence data of frame torsional stiffness on ground load; and generate a sixth relationship curve based on the influence data of frame torsional stiffness on peak-to-peak acceleration.

[0091] It should be noted that the foregoing explanation of the embodiment of the torsional stiffness matching method for new energy off-road vehicles also applies to the torsional stiffness matching device for new energy off-road vehicles in this embodiment, and will not be repeated here.

[0092] According to the torsional stiffness matching device for new energy off-road vehicles proposed in this application, by establishing a whole vehicle finite element model and a whole vehicle multibody dynamics model of the new energy off-road vehicle, structural stress data, ground load data and peak-to-peak acceleration data under different body and frame torsional stiffness are obtained. Then, combined with the performance requirements of the vehicle, the target range of body torsional stiffness and frame torsional stiffness is determined. This improves the stiffness redundancy and unreasonable stiffness matching caused by the benchmarking method used to determine stiffness in related technologies, making the body and frame stiffness more compatible, and improving the vehicle's structural reliability, off-road passability and driving smoothness.

[0093] Figure 16 A schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device may include: The memory 1601, the processor 1602, and the computer program stored on the memory 1601 and executable on the processor 1602.

[0094] When the processor 1602 executes the program, it implements the torsional stiffness matching method for new energy off-road vehicles provided in the above embodiments.

[0095] Furthermore, electronic devices also include: Communication interface 1603 is used for communication between memory 1601 and processor 1602.

[0096] The memory 1601 is used to store computer programs that can run on the processor 1602.

[0097] The memory 1601 may include high-speed RAM (Random Access Memory) memory, and may also include non-volatile memory, such as at least one disk storage.

[0098] If the memory 1601, processor 1602, and communication interface 1603 are implemented independently, then the communication interface 1603, memory 1601, and processor 1602 can be interconnected via a bus to complete communication between them. The bus can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, etc. The bus can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 16 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0099] Optionally, in a specific implementation, if the memory 1601, processor 1602, and communication interface 1603 are integrated on a single chip, then the memory 1601, processor 1602, and communication interface 1603 can communicate with each other through an internal interface.

[0100] The processor 1602 may be a CPU (Central Processing Unit), an ASIC (Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of this application.

[0101] This application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for matching torsional stiffness of new energy off-road vehicles.

[0102] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. 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. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0103] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0104] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0105] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any of the following techniques known in the art, or a combination thereof: 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 (FPGAs), field-programmable gate arrays (FPGAs), etc.

[0106] Those skilled in the art will understand that all or part of the steps of the methods implementing the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0107] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A method for matching the torsional stiffness of a new energy off-road vehicle, characterized in that, Includes the following steps: Establish a finite element model and a multibody dynamics model of the new energy off-road vehicle; Based on the finite element model of the whole vehicle, a body frame model with different torsional stiffness is matched, and the structural stress data and ground load data under different torsional stiffness of the body frame are calculated using the body frame model. Based on the vehicle multibody dynamics model, body frame flexible bodies with different torsional stiffness are matched, and the peak-to-peak acceleration data under different body frame torsional stiffness are calculated using the body frame flexible bodies. The performance requirements of new energy off-road vehicles are obtained, and the target ranges of body torsional stiffness and frame torsional stiffness are determined based on the performance requirements, structural stress data, ground load data, and peak-to-peak acceleration data.

2. The torsional stiffness matching method for new energy off-road vehicles according to claim 1, characterized in that, The finite element model of the whole vehicle includes the body, frame, suspension and powertrain, and the multibody dynamics model of the whole vehicle includes the body, frame, suspension, powertrain and steering subsystem.

3. The torsional stiffness matching method for new energy off-road vehicles according to claim 1, characterized in that, Before matching body and frame models with different torsional stiffnesses based on the aforementioned whole vehicle finite element model, the following steps are also included: Set the body weight and frame weight of the finite element model of the whole vehicle; After applying boundary conditions to the finite element model of the vehicle, simulation was performed under the target gravity load; Extract the wheel ground load from the simulation data, calculate the actual deviation between the wheel ground load and the reference ground load, and if the deviation is greater than or equal to the preset deviation, adjust the vehicle body counterweight and the frame counterweight; otherwise, match vehicle body and frame models with different torsional stiffness based on the whole vehicle finite element model.

4. The torsional stiffness matching method for new energy off-road vehicles according to claim 1, characterized in that, Before matching flexible body frames with different torsional stiffnesses based on the aforementioned vehicle multibody dynamics model, the following is also included: Set the assembly mass, center of mass position, and spring load of the vehicle multibody dynamics model; Apply a full load to the center of mass position and calculate the displacement of the front wheel center and the displacement of the rear wheel center. Calculate the displacement difference between the front wheel center displacement and the rear wheel center displacement. If the displacement difference is greater than or equal to a preset difference, adjust at least one of the assembly mass, the center of gravity position, and the spring load. Otherwise, match flexible body frames with different torsional stiffnesses based on the vehicle multibody dynamics model.

5. The torsional stiffness matching method for new energy off-road vehicles according to claim 1, characterized in that, The step of determining the target range of vehicle body torsional stiffness and the target range of frame torsional stiffness based on the performance requirements, structural stress data, ground load data, and peak-to-peak acceleration data includes: Extract the data related to the torsional stiffness of the vehicle body and the data related to the torsional stiffness of the frame from the structural stress data, the ground load data, and the peak-to-peak acceleration data, respectively. Multiple body torsional stiffness influence curves are generated based on the body torsional stiffness related influence data, and multiple frame torsional stiffness influence curves are generated based on the frame torsional stiffness related influence data. Based on the performance requirements, multiple body torsional stiffness influence curves, and multiple frame torsional stiffness influence curves, the target ranges for body torsional stiffness and frame torsional stiffness are determined.

6. The torsional stiffness matching method for new energy off-road vehicles according to claim 5, characterized in that, The generation of multiple body torsional stiffness influence curves based on the body torsional stiffness related influence data includes: Extract the data on the influence of torsional stiffness of the vehicle body on structural stress, the data on the influence of torsional stiffness of the vehicle body on ground load, and the data on the influence of torsional stiffness of the vehicle body on peak-to-peak acceleration from the data on the influence of torsional stiffness of the vehicle body. A first relationship curve is generated based on the data on the influence of the vehicle body torsional stiffness on structural stress. A second relationship curve is generated based on the data on the influence of the vehicle body torsional stiffness on the ground load. A third relationship curve is generated based on the data on the influence of the vehicle body torsional stiffness on the peak-to-peak value of acceleration.

7. The torsional stiffness matching method for new energy off-road vehicles according to claim 5, characterized in that, The generation of multiple frame torsional stiffness influence curves based on the frame torsional stiffness related influence data includes: Extract the data on the influence of frame torsional stiffness on structural stress, the data on the influence of frame torsional stiffness on ground load, and the data on the influence of frame torsional stiffness on peak-to-peak acceleration from the data on the influence of frame torsional stiffness. A fourth relationship curve is generated based on the data on the influence of the frame torsional stiffness on structural stress. A fifth relationship curve is generated based on the data on the influence of the frame torsional stiffness on the ground load. A sixth relationship curve is generated based on the data on the influence of the frame torsional stiffness on the peak-to-peak value of acceleration.

8. A torsional stiffness matching device for new energy off-road vehicles, characterized in that, include: A module is established to create the whole vehicle finite element model and the whole vehicle multibody dynamics model of the new energy off-road vehicle; The first calculation module is used to match the vehicle frame model with different torsional stiffness based on the whole vehicle finite element model, and to use the vehicle frame model to calculate the structural stress data and ground load data under different vehicle frame torsional stiffness. The second calculation module is used to match flexible body frames with different torsional stiffnesses based on the vehicle multibody dynamics model, and to use the flexible body frames to calculate the peak-to-peak acceleration data under different torsional stiffnesses of the body frames. The determination module is used to obtain the performance requirements of new energy off-road vehicles, and to determine the target range of body torsional stiffness and frame torsional stiffness based on the performance requirements, the structural stress data, the ground load data and the peak-to-peak acceleration data.

9. An electronic device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the torsional stiffness matching method for new energy off-road vehicles according to any one of claims 1-7.

10. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed, they implement the torsional stiffness matching method for new energy off-road vehicles as described in any one of claims 1-7.

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