A method and system for designing a monoclinic arm rear suspension DMU model and a storage medium

Abstract

This application discloses a DMU model design method, system, and storage medium for a single-wishbone rear suspension. Based on the structural characteristics of the single-wishbone rear suspension, the method establishes a database containing physical hardpoints and derived geometric features. By defining derived geometric features, the kinematic logic of the suspension is embedded in the database, giving the model not only geometric shape but also kinematic semantics. The suspension is divided into multiple sub-models such as the body, control arms, and springs, and these are bound to the database to achieve linked updates of geometric positions. In a virtual assembly environment, motion simulation is performed by configuring kinematic pairs based on hardpoints and applying wheel hop drive. This design method achieves data-driven parametric modeling, enabling rapid response to design changes, automatic generation of wheel camber angle and drive shaft length variation curves, effective evaluation of suspension kinematic performance, and significantly improved suspension development efficiency and design rationality.

Description

Technical Field

[0001] This application relates to the field of digital design of suspension systems, specifically to a single oblique arm rear suspension DMU model design method, system, and storage medium. Background Technology

[0002] In the field of digital design of automotive chassis suspension systems, the single-wishbone rear suspension is widely used in the rear axle layout of modern passenger vehicles due to its advantages such as compact structure, high lateral stiffness, and small footprint. With the in-depth application of CAE (Computer-Aided Engineering) and DMU (Digital Prototyping Unit) technologies, the kinematic and dynamic performance analysis of suspension systems has gradually shifted from traditional physical bench tests to virtual simulation verification. However, existing suspension modeling methods suffer from problems such as low parameterization, cumbersome model modification, and simulation results lagging behind design changes, which seriously restrict development efficiency.

[0003] Traditional single-wishbone rear suspension modeling typically employs a geometry-driven approach, directly assembling components based on fixed CAD geometry, lacking independent parametric management of key physical hardpoints. These physical hardpoints are core coordinates determining the suspension's kinematic performance, such as the inner and outer hinge points of the single-wishbone arm, and the mounting points of the springs and shock absorbers. In existing technologies, if the hardpoint coordinates determined in the initial design phase need adjustment, engineers often need to manually reposition the geometric features of multiple components. This is not only labor-intensive but also highly susceptible to assembly errors or motion interference due to overlooking related parts.

[0004] Furthermore, existing modeling methods have significant shortcomings in handling derived geometric features. For example, the motion of a single-arm rear suspension is essentially a rotation around a "virtual rotation axis" formed by the line connecting its inner and outer points. The spatial position of this axis and its midpoint are crucial for defining the swing arm's motion constraints. However, traditional methods often treat this axis as an implicit geometric relationship rather than an explicit parametric feature, making it difficult for the swing arm's rotation center to automatically update with changes in hard point coordinates during wheel jump simulations. Simultaneously, in sub-model partitioning, existing technologies often treat elastic elements such as springs and shock absorbers as single rigid bodies, failing to realistically simulate their axial extension and contraction during compression and rebound, thus affecting the accuracy of interference calculations in motion simulations.

[0005] More critically, existing technologies lack a systematic parameter linkage mechanism in the configuration and simulation analysis of kinematic pairs. When performing wheel hop kinematic analysis, it is often necessary to redefine driving conditions, and the acquisition and post-processing of simulation data (such as wheel camber angle and drive shaft length changes) are scattered across different software modules, lacking closed-loop evaluation capabilities based on a single database. This data silo phenomenon makes it difficult for designers to quickly determine the specific impact of hardpoint parameter adjustments on suspension performance, hindering the implementation of an integrated "design-simulation-optimization" process. Summary of the Invention

[0006] This application provides a design method, system, device, and storage medium for a single-swing arm rear suspension DMU model. It addresses the problem in existing technologies where the motion of a single-swing arm rear suspension essentially revolves around a virtual rotation axis formed by the line connecting its inner and outer points. The spatial position of this axis and its midpoint are crucial for defining the swing arm's motion constraints. However, traditional methods often treat this axis as an implicit geometric relationship rather than an explicit parametric feature, leading to the technical problem that the swing arm's rotation center is difficult to automatically update with changes in hard point coordinates during wheel jump simulations.

[0007] In a first aspect, embodiments of this application provide a design method for a single-arm rear suspension DMU model, comprising the following steps: Based on the structural characteristics of the single-slant arm rear suspension, a database containing physical hard points and derived geometric features is established; the derived geometric features include at least the equivalent hard point of the single-slant arm; the equivalent hard point of the single-slant arm is the midpoint of the line connecting the outer point and the inner point of the single-slant arm, and the connecting line is the virtual rotation axis of the single-slant arm. The single-wishbone rear suspension is divided into multiple sub-models, and each sub-model is bound to the database so that the geometric position of the sub-model changes in response to the database parameters. In the virtual assembly environment, kinematic pairs are configured for each sub-model based on the physical hard points and derived geometric features, and then wheel jump stroke drive is applied to perform motion simulation; the geometric position of the sub-model of the single oblique arm rear suspension is automatically updated in response to changes in the database.

[0008] Preferably, the single-wishbone rear suspension is divided into multiple sub-models, and each sub-model is bound to the database through a parameter referencing mechanism, specifically including: Each sub-model is grouped together, and the corresponding physical hard points and derived geometric features, as well as the corresponding coordinates, are matched for each group to complete the group matching; there are common hard points or derived geometric features between sub-models; After group matching, obtain the coordinate information of the sub-model and the coordinates of its corresponding physical hard points or derived geometric features, and then mark the physical hard points or derived geometric features at the corresponding positions in the sub-model. When the coordinates of physical hard points or derived geometric features change, mark the changed physical hard points or derived geometric features in the sub-model according to the changed coordinates, and delete the physical hard points or derived geometric features before the change.

[0009] Preferably, the physical hard points include the outer point of the single-slant arm, the inner point of the single-slant arm, the upper hard point of the buffer block, the lower hard point of the buffer block, the inner point of the drive shaft, the outer point of the drive shaft, the right hard point of the stabilizer bar, the left hard point of the stabilizer bar, the hard point on the ball head of the connecting rod, the lower hard point of the ball head of the connecting rod, the lower point of the rear spring, the upper point of the rear spring, the lower point of the shock absorber, the upper point of the shock absorber, and the wheel center.

[0010] Preferably, the multiple sub-models include the body assembly, the rear single-arm assembly, the wheel center motion trajectory, the drive shaft assembly, the drive shaft motion trajectory, the stabilizer bar assembly, the stabilizer bar connecting rod assembly, the upper part of the rear coil spring, the lower part of the rear coil spring, the upper part of the rear shock absorber, and the lower part of the rear shock absorber.

[0011] Preferably, the hard points corresponding to the vehicle body assembly include: the outer point of the single-slant arm, the inner point of the single-slant arm, the equivalent hard point of the single-slant arm, the hard point on the buffer block, the inner point of the drive shaft, the right hard point of the stabilizer bar, the left hard point of the stabilizer bar, the upper point of the rear spring, the upper point of the shock absorber, and the wheel center; The hard points corresponding to the rear single slant arm assembly include: the outer point of the single slant arm, the inner point of the single slant arm, the equivalent hard point of the single slant arm, the lower hard point of the buffer block, the outer point of the drive shaft, the lower point of the rear spring, the lower point of the shock absorber, the upper point of the rear spring, the upper point of the shock absorber, and the wheel center. The hard points corresponding to the drive shaft assembly include: the inner point of the drive shaft and the outer point of the drive shaft; The hard point corresponding to the wheel center's motion trajectory includes: the wheel center; The hard points corresponding to the drive shaft's motion trajectory include: internal points of the drive shaft; The hard points corresponding to the stabilizer bar assembly include: the right hard point of the stabilizer bar, the left hard point of the stabilizer bar, the hard point on the ball head of the connecting rod, and the lower hard point on the ball head of the connecting rod. The hard points corresponding to the stabilizer bar connecting rod assembly include: the hard point on the connecting rod ball head and the hard point below the connecting rod ball head; The hard points corresponding to the upper part of the rear coil spring include: the lower point of the rear spring and the upper point of the rear spring; The hard points corresponding to the lower part of the rear coil spring include: the lower point of the rear spring and the upper point of the rear spring; The hard points corresponding to the upper part of the rear shock absorber include: the lower point of the shock absorber and the upper point of the shock absorber; The hard points corresponding to the lower part of the rear shock absorber include: the lower point of the shock absorber and the upper point of the shock absorber.

[0012] Preferably, in a virtual assembly environment, kinematic pairs are configured for each sub-model based on the physical hard points and derived geometric features, specifically including: Using the direction of the line connecting the outer point and the inner point of the single oblique arm, a rotational constraint is constructed between the rear single oblique arm assembly and the body assembly, so that the rear single oblique arm assembly rotates relative to the body assembly about the virtual rotation axis formed by the connecting line. Using the wheel center, a point-to-surface coupling constraint is established between the rear single-slope arm assembly and the wheel center's motion trajectory, so that the wheel center on the single-slope arm slides on the XY plane of the wheel center's motion trajectory during the motion. Using the wheel center, a prismatic connection is established between the wheel center's motion trajectory and the vehicle body assembly to establish the degree of freedom of the wheel center's motion trajectory relative to the vehicle body assembly, allowing it to move only in the vertical direction; By utilizing the right hard point and left hard point of the stabilizer bar, a rotational engagement is established between the stabilizer bar assembly and the body assembly to achieve the flipping motion of the stabilizer bar assembly relative to the body assembly; By utilizing the hard point on the ball head of the connecting rod, a spherical connection is established between the stabilizer bar connecting rod assembly and the stabilizer bar assembly to achieve multi-angle rotation of the stabilizer bar connecting rod assembly relative to the stabilizer bar assembly; By utilizing the hard point under the ball head of the connecting rod, a universal connection is established between the stabilizer bar connecting rod assembly and the rear single diagonal arm assembly to achieve relative positional constraint between the stabilizer bar connecting rod assembly and the rear single diagonal arm assembly; Using the inner point of the drive shaft, a prismatic connection is established between the drive shaft motion trajectory and the vehicle body assembly to restrict the degree of freedom of the drive shaft motion trajectory relative to the vehicle body assembly, so that it can only move laterally in the Y direction; By utilizing the inner point of the drive shaft, a spherical connection is established between the drive shaft assembly and the drive shaft motion trajectory to achieve multi-angle rotation of the drive shaft assembly relative to the drive shaft motion trajectory; Using the external point of the drive shaft, a universal connection is established between the drive shaft assembly and the rear single-arm assembly to achieve relative positional constraint between the drive shaft assembly and the rear single-arm assembly; By utilizing the upper point of the rear spring, a spherical connection is established between the upper part of the rear coil spring and the vehicle body assembly to achieve multi-angle swing of the upper part of the rear coil spring relative to the vehicle body assembly. By utilizing the upper and lower points of the rear spring, a cylindrical connection is established between the lower and upper parts of the rear coil spring to achieve axial extension and retraction of the lower part of the rear coil spring relative to the upper part of the rear coil spring. Using the lower point of the rear spring, a universal connection is established between the lower part of the rear coil spring and the rear single swashplate assembly to achieve relative positional constraint between the lower part of the rear coil spring and the rear single swashplate assembly; By utilizing the upper point of the shock absorber, a spherical connection is established between the upper part of the rear shock absorber and the vehicle body assembly to achieve multi-angle swing of the upper part of the rear shock absorber relative to the vehicle body assembly. By utilizing the upper and lower points of the shock absorber, a cylindrical connection is established between the upper and lower parts of the rear shock absorber to achieve axial extension and retraction of the lower part of the rear shock absorber relative to the upper part of the rear shock absorber. Using the lower point of the shock absorber, a universal connection is established between the lower part of the rear shock absorber and the rear single-slant arm assembly to achieve relative positional constraint between the lower part of the rear shock absorber and the rear single-slant arm assembly.

[0013] Preferably, motion simulation is performed by applying wheel jump travel drive, specifically including: A vertical displacement driving function is applied to the wheel center's motion trajectory, driving the wheel center to reciprocate vertically within a preset wheel jump range; During the motion simulation, real-time data are collected on the changes in the rotation angle of the rear single-arm assembly around the virtual rotation axis, the changes in the length of the drive shaft assembly, and the changes in the wheel camber angle.

[0014] Preferably, after motion simulation, the following steps are also included: Plot the first curve showing the change of wheel camber angle with wheel travel distance; Plot a second curve showing the changes in the overall length and angle of the drive shaft as a function of wheel travel. The suspension's bounce interference, wheel alignment parameters, and the rationality of the drive shaft arrangement are evaluated based on the first curve, the second curve, and the outer boundary envelope geometric model of the virtual assembly of the single-arm rear suspension.

[0015] Secondly, embodiments of this application provide a single-arm rear suspension DMU model design system, which includes: The first module is used to establish a database containing physical hard points and derived geometric features based on the structural characteristics of the single-slant arm rear suspension; the derived geometric features include at least the equivalent hard point of the single-slant arm; the equivalent hard point of the single-slant arm is the midpoint of the line connecting the outer point and the inner point of the single-slant arm, and the line connecting the two points is the virtual rotation axis of the single-slant arm. The second module is used to divide the single oblique arm rear suspension into multiple sub-models and bind each sub-model to the database so that the geometric position of the sub-model changes with the database parameters. The third module is used to configure kinematic pairs for each sub-model in a virtual assembly environment based on the physical hard points and derived geometric features, and then apply wheel jump stroke drive to perform motion simulation; in response to changes in the database, it automatically updates the geometric position of the sub-model of the single oblique arm rear suspension.

[0016] Thirdly, embodiments of this application provide a computer-readable storage medium storing a single-wishbone rear suspension DMU model design program, wherein when the single-wishbone rear suspension DMU model design program is executed by a processor, it implements the steps of a single-wishbone rear suspension DMU model design method.

[0017] The beneficial effects of the technical solutions provided in this application include: By defining derived geometric features, the kinematic logic of the suspension is embedded in the database, giving the model not only geometric form but also kinematic semantics. Furthermore, each sub-model is bound to the database, allowing the geometric position of the sub-model to change in response to database parameters. When hardpoint parameters in the database change, all bound sub-models automatically update their geometric positions, achieving a global impact from a single modification. This parametric design method significantly improves the model's reusability and adaptability, enabling rapid suspension redesign for different vehicle platforms and significantly shortening the design cycle. Attached Figure Description

[0018] Figure 1 A schematic diagram showing the numbering of the hardpoints of the single-arm rear suspension in this application; Figure 2 This is a flowchart illustrating the design method of the single-arm rear suspension DMU model in this application. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0020] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0021] In a first aspect, embodiments of this application provide a design method for a single-arm rear suspension DMU model, comprising the following steps: Step 100: Based on the structural features of the single-slant arm rear suspension, establish a database containing physical hard points and derived geometric features; the derived geometric features include at least the equivalent hard point of the single-slant arm; the equivalent hard point of the single-slant arm is the midpoint of the line connecting the outer point and the inner point of the single-slant arm, and the line is the virtual rotation axis of the single-slant arm. Step 200: Divide the single-arm rear suspension into multiple sub-models and bind each sub-model to the database so that the geometric position of the sub-model changes with the database parameters. Step 300: In the virtual assembly environment, based on the physical hard points and derived geometric features, configure kinematic pairs for each sub-model to form the outer boundary envelope geometric model of the single oblique arm rear suspension, including the tires. Then, apply wheel jump stroke drive to perform motion simulation; automatically update the geometric position of the sub-model of the single oblique arm rear suspension in response to changes in the database.

[0022] By defining derived geometric features, the kinematic logic of the suspension is embedded in the database, giving the model not only geometric form but also kinematic semantics. Furthermore, each sub-model is bound to the database, allowing the geometric position of the sub-model to change in response to database parameters. When hardpoint parameters in the database change, all bound sub-models automatically update their geometric positions, achieving a global impact from a single modification. This parametric design method significantly improves the model's reusability and adaptability, enabling rapid suspension redesign for different vehicle platforms and significantly shortening the design cycle.

[0023] In some embodiments, the single-wishbone rear suspension is divided into multiple sub-models, and each sub-model is bound to the database through a parameter referencing mechanism, specifically including: Each sub-model is grouped together, and the corresponding physical hard points and derived geometric features, as well as the corresponding coordinates, are matched for each group to complete the group matching; there are common hard points or derived geometric features between sub-models; After group matching, obtain the coordinate information of the sub-model and the coordinates of its corresponding physical hard points or derived geometric features, and then mark the physical hard points or derived geometric features at the corresponding positions in the sub-model. When the coordinates of physical hard points or derived geometric features change, mark the changed physical hard points or derived geometric features in the sub-model according to the changed coordinates, and delete the physical hard points or derived geometric features before the change.

[0024] The grouping and matching mechanism, along with hardpoint sharing, ensures logical consistency in the assembly of the multibody system. Encapsulating sub-models into groups and binding their coordinates decouples the complex suspension system into multiple independent parametric modules, facilitating version management and collaborative design. Specifically, the "mark new hardpoints and delete old hardpoints" operation logic ensures that only currently valid geometric constraints are displayed in the model view during design iterations, avoiding interference from historical data. This mechanism effectively improves model readability and maintainability, preventing misassembly or incorrect kinematic pair definitions caused by residual old hardpoints.

[0025] In some embodiments, physical hard points include the outer point of the single-slope arm, the inner point of the single-slope arm, the upper hard point of the buffer block, the lower hard point of the buffer block, the inner point of the drive shaft, the outer point of the drive shaft, the right hard point of the stabilizer bar, the left hard point of the stabilizer bar, the hard point on the ball joint of the connecting rod, the lower hard point of the ball joint of the connecting rod, the lower point of the rear spring, the upper point of the rear spring, the lower point of the shock absorber, the upper point of the shock absorber, and the wheel center. Refer to Table 1 and... Figure 1 The database is shown in the figure.

[0026]

[0027] Table 1 A systematic, exhaustive, and standardized definition of physical hardpoints was conducted, constructing a complete benchmark for suspension kinematic analysis. This comprehensive list of hardpoints covers all critical connection nodes of the suspension system: from the inner and outer points of the single-arm swing arm that determine the swing arm's center of rotation, to the drive shaft points that transmit longitudinal forces, to the stabilizer bar points that control roll characteristics, and the buffer block points that limit the movement. This standardized data definition method ensures that the DMU model can accurately reproduce the constraints of the real physical system, providing high-fidelity input data for subsequent kinematic pair configurations, avoiding simulation distortion caused by missing key points, and improving the reliability of the analysis results.

[0028] In some embodiments, multiple sub-models include a body assembly, a rear single-wishbone assembly, a wheel center motion trajectory, a drive shaft assembly, a drive shaft motion trajectory, a stabilizer bar assembly, a stabilizer bar connecting rod assembly, an upper rear coil spring, a lower rear coil spring, an upper rear shock absorber, and a lower rear shock absorber. The sub-model partitioning strategy fully considers the motion characteristics and functional independence of each suspension component. Specifically, "wheel center motion trajectory" and "drive shaft motion trajectory" are introduced as independent auxiliary sub-models, providing a logical framework for subsequent kinematic pair configuration. Simultaneously, the springs and shock absorbers are separated into upper and lower parts to simulate their relative slip motion during actual operation. This partitioning method not only conforms to physical reality but also facilitates the application of specific motion constraints to different components in the virtual assembly environment, thereby improving the accuracy and convergence of multibody dynamics simulation.

[0029] In some embodiments, reference is made to Table 2:

[0030] Table 2 The hard points corresponding to the body assembly include: the outer point of the single-slant arm, the inner point of the single-slant arm, the equivalent hard point of the single-slant arm, the hard point on the buffer block, the inner point of the drive shaft, the right hard point of the stabilizer bar, the left hard point of the stabilizer bar, the upper point of the rear spring, the upper point of the shock absorber, and the wheel center. The hard points corresponding to the rear single slant arm assembly include: the outer point of the single slant arm, the inner point of the single slant arm, the equivalent hard point of the single slant arm, the lower hard point of the buffer block, the outer point of the drive shaft, the lower point of the rear spring, the lower point of the shock absorber, the upper point of the rear spring, the upper point of the shock absorber, and the wheel center. The hard points corresponding to the drive shaft assembly include: the inner point of the drive shaft and the outer point of the drive shaft; The hard points corresponding to the wheel center's motion trajectory include: the wheel center; The hard points corresponding to the drive shaft's motion trajectory include: internal points of the drive shaft; The hard points corresponding to the stabilizer bar assembly include: the right hard point of the stabilizer bar, the left hard point of the stabilizer bar, the hard point on the ball head of the connecting rod, and the lower hard point on the ball head of the connecting rod. The hard points corresponding to the stabilizer bar connecting rod assembly include: the hard point on the connecting rod ball head and the hard point below the connecting rod ball head; The hard points corresponding to the upper part of the rear coil spring include: the lower point of the rear spring and the upper point of the rear spring; The hard points corresponding to the lower part of the rear coil spring include: the lower point of the rear spring and the upper point of the rear spring; The hard points corresponding to the upper part of the rear shock absorber include: the lower point of the shock absorber and the upper point of the shock absorber; The hard points corresponding to the lower part of the rear shock absorber include: the lower point of the shock absorber and the upper point of the shock absorber.

[0031] Detailed mapping relationships ensure that the positioning of each component has clear parameter basis. For example, by specifying that the "body assembly" is associated with the "upper hard point of the buffer block," and the "rear single-slant arm assembly" is associated with the "lower hard point of the buffer block," the system can accurately identify the change in the contact position of the buffer block during compression. This refined data association mechanism allows the system to accurately calculate the displacement and rotation of each sub-model when making parameter modifications, thereby ensuring the correctness and continuity of the suspension kinematics.

[0032] In some embodiments, reference is made to Table 3:

[0033] Table 3 In a virtual assembly environment, kinematic pairs are configured for each sub-model based on physical hard points and derived geometric features, specifically including: By utilizing the direction of the line connecting the outer point and the inner point of the single-slant arm, a rotational constraint is constructed between the rear single-slant arm assembly and the body assembly, so that the rear single-slant arm assembly rotates relative to the body assembly around the virtual rotation axis formed by the connecting line. Using the wheel center, a point-to-surface coupling constraint is established between the rear single-slope arm assembly and the wheel center's motion trajectory, so that the wheel center on the single-slope arm slides on the XY plane of the wheel center's motion trajectory during the motion, which is consistent with the actual vehicle's motion trajectory; By utilizing the wheel center, a prismatic connection is established between the wheel center's motion trajectory and the vehicle body assembly to establish the degree of freedom of the wheel center's motion trajectory relative to the vehicle body assembly, allowing it to move only in the vertical direction; By utilizing the right hard point and left hard point of the stabilizer bar, a rotational engagement is established between the stabilizer bar assembly and the body assembly to achieve the flipping motion of the stabilizer bar assembly relative to the body assembly; By utilizing the hard point on the ball end of the connecting rod, a spherical connection is established between the stabilizer bar connecting rod assembly and the stabilizer bar assembly to enable multi-angle rotation of the stabilizer bar connecting rod assembly relative to the stabilizer bar assembly; By utilizing the hard point under the ball joint of the connecting rod, a universal connection is established between the stabilizer bar connecting rod assembly and the rear single diagonal arm assembly to achieve relative positional constraint between the stabilizer bar connecting rod assembly and the rear single diagonal arm assembly; By utilizing the interior point of the drive shaft, a diamond-shaped connection is established between the drive shaft's motion trajectory and the vehicle body assembly to restrict the degree of freedom of the drive shaft's motion trajectory relative to the vehicle body assembly, allowing it to only move laterally along the Y direction. By utilizing the inner point of the drive shaft, a spherical connection is established between the drive shaft assembly and the drive shaft motion trajectory to achieve multi-angle rotation of the drive shaft assembly relative to the drive shaft motion trajectory; By utilizing the external point of the drive shaft, a universal connection is established between the drive shaft assembly and the rear single-slant arm assembly to achieve relative positional constraints between the drive shaft assembly and the rear single-slant arm assembly; By utilizing the upper point of the rear spring, a spherical connection is established between the upper part of the rear coil spring and the body assembly to achieve multi-angle swing of the upper part of the rear coil spring relative to the body assembly. By utilizing the upper and lower points of the rear spring, a cylindrical connection is established between the lower and upper parts of the rear coil spring to achieve axial extension and retraction of the lower part of the rear coil spring relative to the upper part of the rear coil spring. By utilizing the lower point of the rear spring, a universal connection is established between the lower part of the rear coil spring and the rear single swashplate assembly to achieve relative positional constraint between the lower part of the rear coil spring and the rear single swashplate assembly. By utilizing the upper point of the shock absorber, a spherical connection is established between the upper part of the rear shock absorber and the body assembly to achieve multi-angle swing of the upper part of the rear shock absorber relative to the body assembly. By utilizing the upper and lower points of the shock absorber, a cylindrical connection is established between the upper and lower parts of the rear shock absorber to achieve axial extension and retraction of the lower part of the rear shock absorber relative to the upper part of the rear shock absorber. By utilizing the lower point of the shock absorber, a universal connection is established between the lower part of the rear shock absorber and the rear single-slant arm assembly to achieve relative positional constraint between the lower part of the rear shock absorber and the rear single-slant arm assembly.

[0034] A precise configuration of kinematic pairs conforming to physical realities was achieved. Rotational constraints simulated the swing arm's oscillation around a virtual axis; point-to-surface coupling and prismatic coupling simulated the vertical movement of the wheel center, acting as a guide while releasing the wheel center's degrees of freedom in the XY plane, aligning with the motion trajectory of the wheel center on the entire vehicle; and cylindrical coupling simulated the axial extension and contraction of the shock absorber and spring. This precise constraint configuration based on hard-point coordinates constructed a virtual prototype with reasonable degrees of freedom and realistic motion relationships. Compared to the simplified fixed assembly in traditional methods, this approach accurately captures the interference risks and motion interference of the suspension at its limit travel, significantly improving the realism of the simulation and its engineering guidance value.

[0035] In some embodiments, motion simulation is performed by applying wheel travel drive, specifically including: A vertical displacement driving function is applied to the wheel center's motion trajectory, driving the wheel center to reciprocate vertically within a preset wheel jump range; During the motion simulation, real-time data are collected on the changes in the rotation angle of the rear single-arm assembly around the virtual rotation axis, the changes in the length of the drive shaft assembly, and the changes in the wheel camber angle.

[0036] By applying a driving function along the wheel center trajectory, the vertical bouncing process of a wheel encountering a bump was simulated. During the simulation, the system collected key performance indicators in real time: the swing arm angle reflects the suspension's travel, the change in drive shaft length directly relates to the universal joint's slip performance, and the change in wheel camber angle is the core indicator for evaluating tire contact performance. This real-time data collection provides the initial basis for the quantitative analysis of suspension performance, enabling designers to intuitively understand the suspension's dynamic performance throughout its entire travel and promptly identify potential design flaws.

[0037] In some embodiments, the following steps are included after motion simulation: Plot the first curve showing the change of wheel camber angle with wheel travel distance; Plot a second curve showing how the overall length and arrangement angle of the drive shaft change with the wheel travel. The suspension's bounce interference, wheel alignment parameters, and the rationality of the drive shaft arrangement are evaluated based on the first curve, the second curve, and the outer boundary envelope geometric model of the virtual assembly of the single-arm rear suspension.

[0038] Transforming collected data into intuitive "performance curves" makes abstract numerical changes visible. Designers can observe the trend of the "wheel camber angle curve" to determine whether the tire maintains an ideal contact posture during compression stroke; by analyzing the "drive shaft length variation curve," they can accurately calculate the extension and contraction of the drive shaft at its limit stroke, thereby assessing whether there is any interference risk. This curve-based evaluation mechanism can quickly identify design defects, guide engineers to retrospectively modify hardpoint parameters in the database, and thus optimize suspension performance. Compared to the traditional development model that relies on experience-based trial and error, this solution achieves data-driven precision optimization, significantly improving design quality and development efficiency. The first and second curves can be cross-analyzed to draw conclusions, for example: Cross-analyzing the first curve (wheel camber angle vs. wheel travel) with the second curve (drive shaft length change vs. wheel travel) and drive shaft arrangement angle vs. wheel travel is an important means of evaluating the rationality of suspension design.

[0039] Through this cross-analysis, the following conclusions can be drawn: A. Assess the relationship between "interference amount" and "motion coordination". The change in drive shaft length directly reflects the slippage requirement of the half-shaft universal joint during runout. If the change in drive shaft length is too large, it will cause the half-shaft slippage to exceed the design stroke, resulting in interference or abnormal noise.

[0040] It can be confirmed that the angle of the drive shaft changes during the suspension movement. When the angle of the drive shaft exceeds the design specifications, abnormal noise may occur.

[0041] Motion coordination warning: If the slope (rate of change) of the drive shaft length change curve is abnormally steep in a certain range, and the corresponding wheel camber angle change is also large, it indicates that the suspension does not move smoothly in this travel range, and there may be a risk of bouncing interference. The hard points need to be optimized to smooth the curve.

[0042] Motion interference inspection: By creating the outer boundary envelope of the single-wishbone rear suspension, the clearance between the moving parts of the suspension and the fixed body, powertrain and other peripheral components is checked to avoid motion interference problems between the single-wishbone rear suspension and peripheral components in the actual vehicle.

[0043] B. Verify the overall impact of "hard spot modifications" Modifying the hard point coordinates in the database will update both curves simultaneously.

[0044] Suppose that the inner point position of the single slant arm is adjusted to improve ground contact performance (ideally maintaining a negative camber gradient and good linearity during wheel bounce), this may cause a virtual rotation axis offset. Through cross-analysis, you might find that while the first curve shows improved camber characteristics, the second curve shows a larger change in drive shaft length.

[0045] This cross-analysis helps engineers find the Pareto optimal solution—that is, to find the ideal combination of hard point coordinates for the wheel camber angle characteristics while ensuring that the change in drive shaft length is within the allowable tolerance range (e.g., ±5mm).

[0046] Secondly, embodiments of this application also provide a single-arm rear suspension DMU model design system, which includes: The first module is used to establish a database containing physical hard points and derived geometric features based on the structural characteristics of the single-slant arm rear suspension. The derived geometric features include at least the equivalent hard point of the single-slant arm. The equivalent hard point of the single-slant arm is the midpoint of the line connecting the outer point and the inner point of the single-slant arm, and the line is the virtual rotation axis of the single-slant arm. The second module is used to divide the single oblique arm rear suspension into multiple sub-models and bind each sub-model to the database so that the geometric position of the sub-model changes with the database parameters. The third module is used to configure kinematic pairs for each sub-model in a virtual assembly environment based on physical hard points and derived geometric features, and then apply wheel jump stroke drive to perform motion simulation; it automatically updates the geometric position of the sub-model of the single oblique arm rear suspension in response to changes in the database.

[0047] The functions of each module in the above-mentioned single-wishbone rear suspension DMU model design system correspond to the steps in the above-mentioned single-wishbone rear suspension DMU model design method embodiment, and their functions and implementation processes will not be described in detail here.

[0048] This application embodiment also provides a single-wishbone rear suspension DMU model design device, which can be a personal computer (PC), laptop computer, server or other device with data processing capabilities.

[0049] In this embodiment of the application, the single-arm rear suspension DMU model design device may include a processor, a memory, a communication interface, and a communication bus.

[0050] The communication bus can be of any type and is used to interconnect the processor, memory, and communication interface.

[0051] The communication interface includes input / output (I / O) interfaces, physical interfaces, and logical interfaces used for interconnecting components within the single-wishbone rear suspension DMU model design device, as well as interfaces used for interconnecting the single-wishbone rear suspension DMU model design device with other devices (such as other computing devices or user equipment). Physical interfaces can be Ethernet interfaces, fiber optic interfaces, ATM interfaces, etc.; user equipment can be displays, keyboards, etc.

[0052] Memory can be various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disk, programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), etc.

[0053] The processor can be a general-purpose processor, which can call the single-wishbone rear suspension DMU model design program stored in memory and execute the single-wishbone rear suspension DMU model design method provided in the embodiments of this application. For example, the general-purpose processor can be a central processing unit (CPU). The method executed when the single-wishbone rear suspension DMU model design program is called can be referred to in the various embodiments of the single-wishbone rear suspension DMU model design method of this application, and will not be repeated here.

[0054] This application also provides a computer-readable storage medium.

[0055] The computer-readable storage medium of this application stores a single-wishbone rear suspension DMU model design program, wherein when the single-wishbone rear suspension DMU model design program is executed by a processor, it implements the steps of the single-wishbone rear suspension DMU model design method as described above.

[0056] The method implemented when the single-wishbone rear suspension DMU model design program is executed can be referred to in various embodiments of the single-wishbone rear suspension DMU model design method of this application, and will not be repeated here.

[0057] It should be noted that the sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0058] The terms "comprising" and "having," and any variations thereof, in the specification, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus. The terms "first," "second," and "third," etc., are used to distinguish different objects, etc., and do not indicate a sequence, nor do they limit "first," "second," and "third" to different types.

[0059] In the description of the embodiments of this application, terms such as "exemplary," "for example," or "for instance" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "exemplary," "for example," or "for instance" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary," "for example," or "for instance" is intended to present the relevant concepts in a concrete manner.

[0060] In the description of the embodiments of this application, unless otherwise stated, " / " means "or". For example, A / B can mean A or B. The "and / or" in the text is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more.

[0061] In some processes described in the embodiments of this application, multiple operations or steps are included in a specific order. However, it should be understood that these operations or steps may not be executed in the order they appear in the embodiments of this application, or they may be executed in parallel. The sequence number of the operation is only used to distinguish different operations, and the sequence number itself does not represent any execution order. In addition, these processes may include more or fewer operations, and these operations or steps may be executed sequentially or in parallel, and these operations or steps may be combined.

[0062] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device to execute the methods described in the various embodiments of this application.

[0063] The above are merely preferred embodiments of this application and do not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A design method for a single-arm rear suspension DMU model, characterized in that, Includes the following steps: Based on the structural characteristics of the single-arm rear suspension, a database containing physical hard points and derived geometric features is established; The derived geometric features include at least one equivalent hard point of a single oblique arm; the equivalent hard point of a single oblique arm is the midpoint of the line connecting the outer point and the inner point of the single oblique arm, and the line connecting the two points is the virtual rotation axis of the single oblique arm. The single-wishbone rear suspension is divided into multiple sub-models, and each sub-model is bound to the database so that the geometric position of the sub-model changes in response to the database parameters. In the virtual assembly environment, kinematic pairs are configured for each sub-model based on the physical hard points and derived geometric features, and then wheel jump stroke drive is applied to perform motion simulation; the geometric position of the sub-model of the single oblique arm rear suspension is automatically updated in response to changes in the database.

2. The single-arm rear suspension DMU model design method as described in claim 1, characterized in that, The single-wishbone rear suspension is divided into multiple sub-models, and each sub-model is bound to the database through a parameter referencing mechanism, specifically including: Each sub-model is grouped together, and the corresponding physical hard points and derived geometric features, as well as the corresponding coordinates, are matched for each group to complete the group matching; there are common hard points or derived geometric features between sub-models; After group matching, obtain the coordinate information of the sub-model and the coordinates of its corresponding physical hard points or derived geometric features, and then mark the physical hard points or derived geometric features at the corresponding positions in the sub-model. When the coordinates of physical hard points or derived geometric features change, mark the changed physical hard points or derived geometric features in the sub-model according to the changed coordinates, and delete the physical hard points or derived geometric features before the change.

3. The single-arm rear suspension DMU model design method as described in claim 2, characterized in that: The physical hard points include the outer point of the single-slant arm, the inner point of the single-slant arm, the upper hard point of the buffer block, the lower hard point of the buffer block, the inner point of the drive shaft, the outer point of the drive shaft, the right hard point of the stabilizer bar, the left hard point of the stabilizer bar, the hard point on the ball head of the connecting rod, the lower hard point of the ball head of the connecting rod, the lower point of the rear spring, the upper point of the rear spring, the lower point of the shock absorber, the upper point of the shock absorber, and the wheel center.

4. The single-arm rear suspension DMU model design method as described in claim 3, characterized in that: Multiple sub-models include the body assembly, rear single-arm assembly, wheel center motion trajectory, drive shaft assembly, drive shaft motion trajectory, stabilizer bar assembly, stabilizer bar connecting rod assembly, upper rear coil spring, lower rear coil spring, upper rear shock absorber, and lower rear shock absorber.

5. The single-arm rear suspension DMU model design method as described in claim 4, characterized in that: The hard points corresponding to the vehicle body assembly include: the outer point of the single-slant arm, the inner point of the single-slant arm, the equivalent hard point of the single-slant arm, the hard point on the buffer block, the inner point of the drive shaft, the right hard point of the stabilizer bar, the left hard point of the stabilizer bar, the upper point of the rear spring, the upper point of the shock absorber, and the wheel center. The hard points corresponding to the rear single slant arm assembly include: the outer point of the single slant arm, the inner point of the single slant arm, the equivalent hard point of the single slant arm, the lower hard point of the buffer block, the outer point of the drive shaft, the lower point of the rear spring, the lower point of the shock absorber, the upper point of the rear spring, the upper point of the shock absorber, and the wheel center. The hard points corresponding to the drive shaft assembly include: the inner point of the drive shaft and the outer point of the drive shaft; The hard point corresponding to the wheel center's motion trajectory includes: the wheel center; The hard points corresponding to the drive shaft's motion trajectory include: internal points of the drive shaft; The hard points corresponding to the stabilizer bar assembly include: the right hard point of the stabilizer bar, the left hard point of the stabilizer bar, the hard point on the ball head of the connecting rod, and the lower hard point on the ball head of the connecting rod. The hard points corresponding to the stabilizer bar connecting rod assembly include: the hard point on the connecting rod ball head and the hard point below the connecting rod ball head; The hard points corresponding to the upper part of the rear coil spring include: the lower point of the rear spring and the upper point of the rear spring; The hard points corresponding to the lower part of the rear coil spring include: the lower point of the rear spring and the upper point of the rear spring; The hard points corresponding to the upper part of the rear shock absorber include: the lower point of the shock absorber and the upper point of the shock absorber; The hard points corresponding to the lower part of the rear shock absorber include: the lower point of the shock absorber and the upper point of the shock absorber.

6. The single-arm rear suspension DMU model design method as described in claim 5, characterized in that, In the virtual assembly environment, kinematic pairs are configured for each sub-model based on the physical hard points and derived geometric features, specifically including: Using the direction of the line connecting the outer point and the inner point of the single oblique arm, a rotational constraint is constructed between the rear single oblique arm assembly and the body assembly, so that the rear single oblique arm assembly rotates relative to the body assembly around the virtual rotation axis formed by the connecting line. Using the wheel center, a point-to-surface coupling constraint is established between the rear single-slope arm assembly and the wheel center's motion trajectory, so that the wheel center on the single-slope arm slides on the XY plane of the wheel center's motion trajectory during the motion. Using the wheel center, a prismatic connection is established between the wheel center's motion trajectory and the vehicle body assembly to establish the degree of freedom of the wheel center's motion trajectory relative to the vehicle body assembly, allowing it to move only in the vertical direction; By utilizing the right hard point and left hard point of the stabilizer bar, a rotational engagement is established between the stabilizer bar assembly and the body assembly to achieve the flipping motion of the stabilizer bar assembly relative to the body assembly; By utilizing the hard point on the ball head of the connecting rod, a spherical connection is established between the stabilizer bar connecting rod assembly and the stabilizer bar assembly to achieve multi-angle rotation of the stabilizer bar connecting rod assembly relative to the stabilizer bar assembly; By utilizing the hard point under the ball head of the connecting rod, a universal connection is established between the stabilizer bar connecting rod assembly and the rear single diagonal arm assembly to achieve relative positional constraint between the stabilizer bar connecting rod assembly and the rear single diagonal arm assembly; Using the inner point of the drive shaft, a diamond-shaped connection is established between the drive shaft motion trajectory and the vehicle body assembly to restrict the degree of freedom of the drive shaft motion trajectory relative to the vehicle body assembly, so that it can only move laterally in the Y direction; By utilizing the inner point of the drive shaft, a spherical connection is established between the drive shaft assembly and the drive shaft motion trajectory to achieve multi-angle rotation of the drive shaft assembly relative to the drive shaft motion trajectory; Using the external point of the drive shaft, a universal connection is established between the drive shaft assembly and the rear single-arm assembly to achieve relative positional constraint between the drive shaft assembly and the rear single-arm assembly; By utilizing the upper point of the rear spring, a spherical connection is established between the upper part of the rear coil spring and the vehicle body assembly to achieve multi-angle swing of the upper part of the rear coil spring relative to the vehicle body assembly. By utilizing the upper and lower points of the rear spring, a cylindrical connection is established between the lower and upper parts of the rear coil spring to achieve axial extension and retraction of the lower part of the rear coil spring relative to the upper part of the rear coil spring. Using the lower point of the rear spring, a universal connection is established between the lower part of the rear coil spring and the rear single swashplate assembly to achieve relative positional constraint between the lower part of the rear coil spring and the rear single swashplate assembly; By utilizing the upper point of the shock absorber, a spherical connection is established between the upper part of the rear shock absorber and the vehicle body assembly to achieve multi-angle swing of the upper part of the rear shock absorber relative to the vehicle body assembly. By utilizing the upper and lower points of the shock absorber, a cylindrical connection is established between the upper and lower parts of the rear shock absorber to achieve axial extension and retraction of the lower part of the rear shock absorber relative to the upper part of the rear shock absorber. Using the lower point of the shock absorber, a universal connection is established between the lower part of the rear shock absorber and the rear single-slant arm assembly to achieve relative positional constraint between the lower part of the rear shock absorber and the rear single-slant arm assembly.

7. The single-arm rear suspension DMU model design method as described in claim 6, characterized in that, Motion simulation is performed by applying wheel jump travel drive, specifically including: A vertical displacement driving function is applied to the wheel center's motion trajectory, driving the wheel center to reciprocate vertically within a preset wheel jump range; During the motion simulation, real-time data are collected on the changes in the rotation angle of the rear single-arm assembly around the virtual rotation axis, the changes in the length of the drive shaft assembly, and the changes in the wheel camber angle.

8. The single-arm rear suspension DMU model design method as described in claim 6, characterized in that, Following motion simulation, the following steps are also included: Plot the first curve showing the change of wheel camber angle with wheel travel distance; Plot a second curve showing the changes in the overall length and angle of the drive shaft as a function of wheel travel. The suspension's bounce interference, wheel alignment parameters, and the rationality of the drive shaft arrangement are evaluated based on the first curve, the second curve, and the outer boundary envelope geometric model of the virtual assembly of the single-arm rear suspension.

9. A single-arm rear suspension DMU model design system, characterized in that, It includes: The first module is used to establish a database containing physical hard points and derived geometric features based on the structural characteristics of the single oblique arm rear suspension. The derived geometric features include at least one equivalent hard point of a single oblique arm; the equivalent hard point of a single oblique arm is the midpoint of the line connecting the outer point and the inner point of the single oblique arm, and the line connecting the two points is the virtual rotation axis of the single oblique arm. The second module is used to divide the single oblique arm rear suspension into multiple sub-models and bind each sub-model to the database so that the geometric position of the sub-model changes with the database parameters. The third module is used to configure kinematic pairs for each sub-model in a virtual assembly environment based on the physical hard points and derived geometric features, and then apply wheel jump stroke drive to perform motion simulation; in response to changes in the database, it automatically updates the geometric position of the sub-model of the single oblique arm rear suspension.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a single-wishbone rear suspension DMU model design program, wherein when the single-wishbone rear suspension DMU model design program is executed by a processor, it implements the steps of the single-wishbone rear suspension DMU model design method as described in any one of claims 1 to 8.

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