Suspension system adjustment and vehicle posture matching method

Abstract

This invention discloses a method for adjusting a suspension system and matching vehicle attitude, comprising the following steps: S1, defining the axle load, tire parameters, leaf spring parameters, and leaf spring mounting point position parameters of the vehicle in 3D modeling software; S2, establishing the correlation between the front and rear suspension leaf spring arc height, stiffness, and corresponding axle loads, as well as the correlation between the front and rear tire static radii and corresponding axle loads; S3, constructing a suspension skeleton model including the leaf spring reference point, axle tube center position, wheel center point, and ground line, based on a preset leaf spring reference point; S4, adjusting at least one of the vehicle axle load, suspension stiffness, tire parameters, or leaf spring mounting point position parameters, automatically adjusting the wheel center position and ground line through preset correlations to complete the matching of the suspension system with the vehicle attitude. This method for adjusting a suspension system and matching vehicle attitude can adaptively adjust the leaf spring attitude, wheel center position, and vehicle ground line, reducing matching time and improving suspension design and development efficiency.

Description

Technical Field

[0001] This invention belongs to the field of light truck suspension system design technology. Specifically, this invention relates to a method for adjusting the suspension system and matching the vehicle's posture. Background Technology

[0002] In the design and development of automotive suspensions, lightweight design and handling stability (hereinafter referred to as "handling performance") are key technical objectives, both of which directly affect the vehicle's fuel economy, driving safety, and ride experience. To achieve these objectives, general layout engineers and chassis design engineers need to iterate and optimize key design parameters such as vehicle axle load, suspension stiffness, leaf spring thickness, leaf spring mounting point location, and tire selection multiple times. The proper matching of these parameters is the core prerequisite for balancing lightweight design and handling performance.

[0003] Simultaneously, after parameter adjustments, three key verification tasks must be completed: first, verifying the change in leaf spring attitude angle to ensure that the leaf spring's working state meets design expectations and does not interfere with surrounding components; second, verifying the change in wheel center position to ensure that wheel alignment parameters meet driving stability requirements; and third, verifying the change in ground line to verify the vehicle's passability and attitude rationality. The results of these verifications directly determine the spatial compatibility of the suspension system with other vehicle components, and are a necessary step in demonstrating the feasibility of the design scheme, running through the entire suspension design and development process.

[0004] Currently, the industry primarily relies on multibody dynamics model building and simulation analysis to verify the adjusted parameters. Specifically, engineers rebuild or modify the multibody dynamics model based on the adjusted axle load, suspension stiffness, hard point location, and other parameters. Through model simulation, they match the hard point location and related parameter relationships, thereby obtaining verification data such as leaf spring attitude angle, wheel center position, and ground line.

[0005] However, existing technical solutions have significant drawbacks and shortcomings: First, the process of building, modifying, and matching parameters of multibody dynamics models is cumbersome and complex, requiring high levels of professional skills from engineers. Furthermore, model adaptation must be repeated after each parameter adjustment, resulting in a massive workload. Second, model building, simulation calculations, and result verification consume a significant amount of time. To meet project development timelines, more human resources are needed for model debugging and parameter matching, which not only increases project development costs but also easily leads to extended design verification cycles due to low model matching efficiency, impacting the overall project schedule. Third, the accuracy of parameter matching in multibody dynamics models depends on engineers' experience, and error accumulation is prone to occur during multiple iterative adjustments, further reducing design efficiency.

[0006] This paper provides a method for adjusting the suspension system and matching the vehicle's posture, particularly focusing on how to reduce matching time, improve suspension design and development efficiency, and optimize project cost control. Summary of the Invention

[0007] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention provides a method for adjusting a suspension system and matching the vehicle's attitude, with the purpose of reducing matching time and improving the efficiency of suspension design and development.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a suspension system adjustment and vehicle attitude matching method, comprising the following steps: S1. In the 3D modeling software, the axle load, tire parameters, leaf spring parameters, and leaf spring mounting point position parameters of the vehicle are defined parametrically. S2. Establish the relationship between the arc height and stiffness of the front and rear suspension leaf springs and the corresponding axle loads, as well as the relationship between the static radius of the front and rear tires and the corresponding axle loads. S3. Using the preset reference point of the leaf spring as a benchmark, build a suspension frame model that includes the leaf spring reference point, the center position of the bridge tube, the wheel center point, and the ground line. S4. Adjust at least one of the following parameters: vehicle axle load, suspension stiffness, tire parameters, or leaf spring mounting point position parameters. Automatically adjust the wheel center position and ground line through preset correlation to complete the matching of the suspension system and the vehicle attitude.

[0009] The tire parameters include tire stiffness and tire free radius; the leaf spring parameters include the length of the first leaf spring of the front suspension, the distance between the center of the first leaf spring of the front suspension and the center of the axle tube, the length of the straight section of the front suspension leaf spring, the deflection of the front suspension leaf spring, the stiffness of the front suspension leaf spring, the initial arc height of the front suspension leaf spring, the length of the first leaf spring of the rear suspension and the length of the straight section of the rear suspension leaf spring; the vehicle axle load includes the front suspension load, the rear suspension load, the unsprung mass of the front suspension and the unsprung mass of the rear suspension.

[0010] The relationship between the front suspension leaf spring arc height and the axle load satisfies: front suspension leaf spring arc height = initial arc height of front suspension leaf spring - front suspension leaf spring deflection, where front suspension leaf spring deflection = (front suspension leaf spring axle load - front suspension unsprung mass) × 9.8 / (front suspension leaf spring stiffness × 2).

[0011] The relationship between the static radius of the tire and the axle load satisfies: Front wheel static radius = tire free radius - front suspension load × 9.8 / (tire stiffness × 2); Rear wheel static radius = tire free radius - rear suspension load × 9.8 / (tire stiffness × 4).

[0012] The preset reference point for the leaf spring is the center of the first leaf of the front suspension leaf spring.

[0013] When building the suspension frame model, the main leaf springs must satisfy the following constraints: The center points of the front and rear bushings of the leaf spring remain fixed; The lower end of the leaf spring lug moves in an arc around the upper end, with the radius of the movement being the length of the lug. The curved section of the leaf spring remains tangent to the straight section; The total length of the leaf spring remains unchanged; Leaf spring installation angle = (length of the first leaf spring - length of the straight section of the leaf spring) / 2 × 180 × 1 deg / (π × leaf spring radius); Leaf spring radius = (length of the first leaf spring - length of the straight section of the leaf spring) / 2 × 180 × 1 deg / (π × leaf spring installation angle).

[0014] In the suspension frame model, the center of the leaf spring main plate is rigidly connected to the wheel center, and a tire profile matching the static radius of the tire is set at the wheel center.

[0015] The ground line is obtained by drawing the common tangent of the front and rear tire profiles.

[0016] The adjustment parameters include the axle loads of the vehicle under no-load, half-load, and full-load conditions.

[0017] The design results output after matching include leaf spring hanger angle, leaf spring hanger point coordinates, wheel center position coordinates, ground line angle, and vehicle attitude angle.

[0018] The suspension system adjustment and vehicle attitude matching method of the present invention can adaptively adjust the leaf spring attitude, wheel center position and vehicle ground line in the early suspension design, tuning and matching verification stages, taking into account the requirements of vehicle axle load, suspension stiffness changes, leaf spring mounting point hard point position changes and tire selection changes. This reduces matching time, improves suspension design and development efficiency, and saves development time for rapid suspension design matching optimization and vehicle layout design. Attached Figure Description

[0019] Figure 1 This is a flowchart of the construction process for a flexible suspension frame model of a light truck; Figure 2 It is a parametric design drawing; Figure 3 It involves creating a formula relationship diagram using CATIA. Figure 4 This is a schematic diagram of the sketch constraints of the main leaf spring. Figure 5 This is a model diagram of a light truck suspension frame; Figure 6 This is a schematic diagram of the vehicle's overall posture; Figure 7 This is a diagram showing the output results of the suspension system matching design for a certain project; The markings in the above figures are as follows: 1. Center point of the front leaf spring bushing; 2. Left and right arc sections; 3. Straight section; 4. Center point of the rear leaf spring bushing; 5. Center point of the leaf spring shackle; 6. Shackle; 7. Leaf spring mounting angle constraint; 8. Leaf spring radius; 9. Shackle length constraint; 10. Bushing radius constraint; 11. Straight section length constraint; 12. Leaf spring arc height constraint; 13. Front wheel center point; 14. Front leaf spring mounting point; 15. 16. Ground line; 17. Center point of the front bushing of the rear leaf spring; 18. Rear wheel center point; 19. Rear leaf spring mounting point; 20. Center point of the rear leaf spring hanger; 21. Center point of the rear bushing of the rear leaf spring; 22. Center point of the front bushing of the front leaf spring; 23. Center point of the rear bushing of the front leaf spring; 24. Reference plane parallel to the frame; 25. Vehicle attitude angle; 26. Angle of the front leaf spring hanger; 27. Angle of the rear leaf spring hanger. Detailed Implementation

[0020] To facilitate understanding of the present invention, a more comprehensive description of the present invention will be given below with reference to the accompanying drawings, which illustrate several embodiments of the present invention. However, the present invention can be implemented in different forms and is not limited to the embodiments described in the text. Rather, these embodiments are provided to make the disclosure of the present invention more thorough and complete.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly associated with those skilled in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments and is not intended to limit the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0022] This invention provides a method for adjusting a suspension system and matching the vehicle's attitude, comprising the following steps: S1. In the 3D modeling software, the axle load, tire parameters, leaf spring parameters, and leaf spring mounting point position parameters of the vehicle are defined parametrically. S2. Establish the relationship between the arc height and stiffness of the front and rear suspension leaf springs and the corresponding axle loads, as well as the relationship between the static radius of the front and rear tires and the corresponding axle loads. S3. Using the preset reference point of the leaf spring as a benchmark, build a suspension frame model that includes the leaf spring reference point, the center position of the bridge tube, the wheel center point, and the ground line. S4. Adjust at least one of the following parameters: vehicle axle load, suspension stiffness, tire parameters, or leaf spring mounting point position parameters. Automatically adjust the wheel center position and ground line through preset correlation to complete the matching of the suspension system and the vehicle attitude.

[0023] Specifically, the embodiments of the present invention belong to the field of light truck suspension system design and development. Based on parametric design, it can adapt to changes in the front and rear axle loads of the vehicle, the position of the leaf spring mounting hard points, the stiffness of the leaf springs, and the tire selection, and quickly output the position of the wheel center and the ground line.

[0024] In this embodiment of the invention, in order to reduce the workload of suspension engineers and vehicle engineers, a method based on rapid matching of vehicle posture is developed. This method can efficiently output the leaf spring mounting posture, wheel center position and ground line under different axle loads, suspension stiffness, hard point positions and tire selection schemes during the design stage, which greatly reduces the matching time and wins valuable design time for automotive design engineers to demonstrate and match the feasibility of the matching scheme.

[0025] In this embodiment of the invention, the suspension system includes a front suspension system and a rear suspension system mounted on a commercial vehicle. The front wheels are mounted on the front axle, which is mounted on the front suspension system. The front axle includes an axle tube. The rear wheels are mounted on the rear axle, which is mounted on the front suspension system. Both the front and rear suspension systems include leaf springs. The leaf springs of the front suspension system are composed of multiple leaf springs of different lengths, arranged sequentially from top to bottom. The uppermost leaf spring is the first leaf spring, which is the longest. Lugs are provided at both ends of the first leaf spring, and bushings are installed in the lugs. The leaf springs of the rear suspension system are also composed of multiple leaf springs of different lengths, arranged sequentially from top to bottom. The uppermost leaf spring is the first leaf spring, which is the longest. Lugs are provided at both ends of the first leaf spring, and bushings are installed in the lugs. The straight section of the leaf spring is horizontal and located in the middle region along its length.

[0026] In step S1 above, the axle load, tire stiffness, leaf spring stiffness, leaf spring length, and leaf spring mounting point position of the vehicle are parametrically designed in CATIA software.

[0027] In this embodiment of the invention, tire parameters include tire stiffness and tire free radius; leaf spring parameters include the length of the first leaf spring of the front suspension, the distance between the center of the first leaf spring of the front suspension and the center of the axle tube, the length of the straight section of the front suspension leaf spring, the deflection of the front suspension leaf spring, the stiffness of the front suspension leaf spring, the initial arc height of the front suspension leaf spring, the length of the first leaf spring of the rear suspension and the length of the straight section of the rear suspension leaf spring; the vehicle axle load includes the front suspension load, the rear suspension load, the unsprung mass of the front suspension and the unsprung mass of the rear suspension.

[0028] In step S2 above, the relationships between the front and rear suspension leaf spring arc height, stiffness, and axle load are established step by step. Based on the installation hardpoint positions of the front and rear leaf springs and the principle that the effective front and rear lengths of the leaf springs remain unchanged under different axle loads, the constraint relationships between the arc height of the first leaf spring and the radius of the main leaf spring are established in the sketching tools of CATIA software. The front and rear axle loads, the arc heights of the front and rear leaf springs, and the attitudes of the front and rear leaf springs are parametrically associated. The relationships between the static radii of the front and rear tires and the front and rear axle loads are established separately.

[0029] In this embodiment of the invention, the relationship between the front suspension leaf spring arc height and the axle load satisfies: Front suspension leaf spring arc height = Initial arc height of front suspension leaf spring - Front suspension leaf spring deflection, where front suspension leaf spring deflection = (Front suspension leaf spring axle load - Unsprung mass of front suspension) × 9.8 / (Front suspension leaf spring stiffness × 2). The leaf spring axle load is the vertical load that the spring must bear when the vehicle is fully loaded.

[0030] In this embodiment of the invention, the relationship between the tire static radius and the axle load satisfies: Front wheel static radius = tire free radius - front suspension load × 9.8 / (tire stiffness × 2); Rear wheel static radius = tire free radius - rear suspension load × 9.8 / (tire stiffness × 4).

[0031] In this embodiment of the invention, the preset reference point for the leaf spring is the center of the first leaf spring of the front suspension. In step S3 above, the center of the first leaf spring of the front suspension and the center of the first leaf spring of the rear suspension are used as preset reference points to build a front suspension system skeleton model and a rear suspension system skeleton model. The front suspension system skeleton model includes the center of the first leaf spring of the front suspension, the center position of the front axle tube, the center point of the front wheel, and the ground line. The rear suspension system skeleton model includes the center of the first leaf spring of the rear suspension, the center position of the rear axle tube, the center point of the rear wheel, and the ground line.

[0032] In this embodiment of the invention, when constructing the front suspension system skeleton model, the main leaf spring meets the following constraints: The center points of the front and rear bushings of the front suspension leaf spring remain fixed; The lower end of the front suspension leaf spring hanger moves in an arc around the upper end, with the radius of the movement being the length of the hanger. The curved section of the front suspension leaf spring remains tangent to the straight section; The total length of the front suspension leaf spring remains unchanged; Front suspension leaf spring installation angle = (length of the first leaf spring - length of the straight section of the leaf spring) / 2 × 180 × 1 deg / (π × radius of the front suspension leaf spring); Front suspension leaf spring radius = (length of the first leaf spring of the front suspension - length of the straight section of the front suspension leaf spring) / 2 × 180 × 1 deg / (π × installation angle of the front suspension leaf spring).

[0033] In this embodiment of the invention, when constructing the rear suspension system skeleton model, the main leaf spring meets the following constraints: The center points of the front and rear bushings of the rear suspension leaf spring remain fixed; The lower end of the rear suspension leaf spring lug moves in an arc around the upper end, with the radius of motion being the length of the lug. The curved section of the rear suspension leaf spring remains tangent to the straight section; The total length of the rear suspension leaf spring remains unchanged; Rear suspension leaf spring installation angle = (length of the first leaf spring of the rear suspension - length of the straight section of the leaf spring) / 2 × 180 × 1 deg / (π × radius of the rear suspension leaf spring); Rear suspension leaf spring radius = (length of the first leaf of the rear suspension leaf spring - length of the straight section of the rear suspension leaf spring) / 2 × 180 × 1 deg / (π × rear suspension leaf spring installation angle).

[0034] In this embodiment of the invention, in the suspension frame model, the center of the leaf spring main plate is rigidly connected to the wheel center, and a tire profile matching the static radius of the tire is set at the wheel center.

[0035] In this embodiment of the invention, the ground line is obtained by drawing the common tangent of the front and rear tire profiles.

[0036] In this embodiment of the invention, by proposing the above-mentioned six quantitative constraints on the main leaf spring, and integrating these constraints with parametric design, key constraints are solidified through formulas. This design eliminates the need for experience-based judgment in model building, ensures unified and traceable constraint logic, and provides a stable logical foundation for subsequent automatic attitude adjustment.

[0037] In this embodiment of the invention, the adjustment parameters include the vehicle axle load corresponding to no load, half load, and full load. In step S4 above, parameters such as different axle loads, front and rear suspension stiffness, tire stiffness and free radius, and leaf spring mounting hard point position are adjusted to automatically adjust the wheel center position and ground line.

[0038] In this embodiment of the invention, the design results output after matching include the leaf spring lug angle, leaf spring lug point coordinates, wheel center position coordinates, ground line angle, and vehicle attitude angle.

[0039] In this embodiment of the invention, the front and rear suspension systems of commercial vehicles are defined independently and parameterized, and their respective leaf spring arc height-stiffness-axle load relationships are established. At the same time, the front and rear suspensions are matched collaboratively through common parameters such as the vehicle axle load and ground line. When any parameter is adjusted, the front and rear suspension models automatically respond and update synchronously without manual intervention. This solves the matching problem of large load differences between the front and rear suspensions of commercial vehicles, significantly reduces the workload of cross-suspension system adjustments, and improves matching efficiency. It also ensures the consistency of the front and rear suspension attitudes and reduces the risk of vehicle attitude deviation.

[0040] In existing technologies, attitude parameters such as leaf spring arc height, tire static radius, and wheel center position require manual calculation and derivation. Input parameters, such as axle load and tire stiffness, necessitate re-analyzing all related data when they change, which is not only inefficient but also prone to human error. In this invention, multi-dimensional input parameters (such as vehicle axle load, tire parameters, and leaf spring parameters) are creatively correlated with output attitude parameters through a quantified formula, establishing a fully automated logic of input change → automatic formula invocation → attitude update. This mechanism eliminates reliance on manual calculation, enabling rapid automatic updates of associated attitude parameters after a single parameter change, improving design response speed while ensuring the accuracy of the quantitative correspondence between parameters and attitudes. Example

[0041] This embodiment provides a method for adjusting the suspension system and matching the vehicle's attitude, including the following steps: S1. In the 3D modeling software, the axle load, tire parameters, leaf spring parameters, and leaf spring mounting point position parameters of the vehicle are defined parametrically. S2. Establish the relationship between the arc height and stiffness of the front and rear suspension leaf springs and the corresponding axle loads, as well as the relationship between the static radius of the front and rear tires and the corresponding axle loads. S3. Using the preset reference point of the leaf spring as a benchmark, build a suspension frame model that includes the leaf spring reference point, the center position of the bridge tube, the wheel center point, and the ground line. S4. Adjust at least one of the following parameters: vehicle axle load, suspension stiffness, tire parameters, or leaf spring mounting point position parameters. Automatically adjust the wheel center position and ground line through preset correlation to complete the matching of the suspension system and the vehicle attitude.

[0042] In step S1, based on the front and rear axle loads input in the overall layout, the sprung mass and unsprung mass, leaf spring stiffness, and initial arc height of the leaf springs under the design loads of the front and rear axles are calculated respectively, and defined as parameters in the CATIA software. (Calculation of sprung mass and unsprung mass, front and rear suspension leaf spring stiffness, and initial arc height of the leaf springs based on front and rear axle loads) like Figure 2 As shown, in CATIA software, the length of the first leaf spring of the front suspension is set to 1060.000 mm, the straight section length of the front suspension leaf spring is set to 120.000 mm, the center distance from the first leaf spring to the center of the axle tube is set to 96.000 mm, and the stiffness of the front suspension leaf spring is set to 7.5000e+004 kg / s. 2 The front suspension load is set to 800.0000 kg, the unsprung mass to 144.0000 kg, the leaf spring deflection to 42.859 mm, the initial leaf spring arc height to 90.000 mm, the final leaf spring arc height to 47.141 mm, the tire free radius to 325.000 mm, and the tire stiffness to 3.2600e+005 kg / s².2 The static radius of the front wheel is set to 312.975 mm, the length of the first leaf spring of the rear suspension is set to 1270.000 mm, the straight section length of the rear suspension leaf spring is set to 300.000 mm, the rear axle load is set to 2000.0000 kg, and the unsprung mass of the rear suspension is set to 279.0000 kg.

[0043] In step S2, the relationship is established in the CATIA software, and the deformation of the leaf springs and tires under the design load (arc height of the front and rear leaf springs, and static radius of the front and rear wheels) is automatically calculated using formulas, such as... Figure 3 As shown.

[0044] Formula (1) is: Front suspension leaf spring arc height = Initial arc height of front suspension leaf spring - Front suspension leaf spring deflection; Formula (2) is: front suspension leaf spring deflection = (front suspension leaf spring load - front suspension unspring mass) * 9.8 / front suspension leaf spring stiffness / 2; Formula (3) is: front wheel static radius = tire free radius - front suspension load * 9.8 / tire stiffness / 2; Formula (4) is: Rear wheel static radius = tire free radius - rear suspension front load * 9.8 / tire stiffness / 4.

[0045] Based on the leaf spring's movement, the main leaf spring (first leaf) is divided into left and right arc sections 2 and a straight section 3 in the middle. The straight section 3 is located in the middle of the left and right arc sections 2. Figure 4 As shown.

[0046] In CATIA software, constraints are established in the sketch, and their main relationships are as follows: 1. The center point 1 of the leaf spring front bushing and the center point 5 of the leaf spring lug remain stationary; 2. The lower end of the leaf spring shackle 6 moves in an arc around the upper end, with a radius equal to the length of the shackle, such as a leaf spring grass. Figure 4 The length constraint of the lifting lug is shown in Figure 9 (the length of the lifting lug is 80mm). 3. The left and right arc sections 2 of the main leaf spring are tangent to the straight section; 4. The total length of the leaf spring remains unchanged; 5. Leaf spring installation angle = (Length of the first leaf spring - Length of the straight section of the leaf spring) / 2) * 180 * 1 degree) / (PI * Leaf spring radius), e.g., leaf spring grass Figure 4 The leaf spring installation angle constraint is shown in Figure 7 (the leaf spring installation angle is 19.344°). 6. The leaf spring radius is = (length of the first leaf spring - length of the straight section of the leaf spring) / 2)*180*1deg) / (PI*leaf spring installation angle), as shown in leaf spring radius constraint 8 in the leaf spring sketch.

[0047] In step S3, as Figure 5 As shown, disregarding the deformation of the front and rear axles and wheel rims, the centers of the main leaf springs of the front and rear suspensions (mounting points 14 and 18 for the front and rear leaf springs, respectively) are rigidly connected to the wheel centers of the front and rear wheels (mounting points 13 and 17 for the rear wheel, respectively). The outlines of the load-bearing tires are then drawn at the wheel centers (the radii of the two circles are the static radii of the front and rear wheels, respectively, and are aligned with the center of the wheel rims). Figure 2 (Parameters are automatically associated). Simultaneously, the common tangent lines of the circular contours of the front and rear wheels are drawn to obtain the tire's ground line 15. Based on the hard points of the front and rear suspensions, the front suspension system skeleton model and the rear suspension system skeleton model are built respectively.

[0048] In step S4, as Figure 5 and Figure 6 As shown, during different design stages, considering axle load changes and front and rear suspension stiffness, the front leaf spring mounting point 14 and the rear leaf spring mounting point 18 are obtained. The front wheel center point position 13 and the rear wheel center point position 17 are obtained by adjusting the distance from the center of the first leaf spring to the center of the axle tube. The ground line 15 is automatically calculated by adjusting tire stiffness and tire free radius. Figure 2 In parametric design using CATIA software, if you manually modify the associated design parameters, CATIA will automatically run the relationships and adjust accordingly. Figure 4 The system automatically generates a suspension frame model based on the leaf spring posture, and can quickly output the leaf spring hanger positions, leaf spring hanger points, front leaf spring hanger angles 26° and 27°, wheel center positions, and overall vehicle attitude angles under no-load, half-load, and full-load conditions (see [reference]). Figure 6 The diagram shows the vehicle's attitude, and the vehicle's attitude angle 25° under different loads, providing important design reference value for data optimization at each stage.

[0049] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A method for adjusting the suspension system and matching the vehicle's attitude, characterized in that, Includes the following steps: S1. In the 3D modeling software, the axle load, tire parameters, leaf spring parameters, and leaf spring mounting point position parameters of the vehicle are defined parametrically. S2. Establish the relationship between the arc height and stiffness of the front and rear suspension leaf springs and the corresponding axle loads, as well as the relationship between the static radius of the front and rear tires and the corresponding axle loads. S3. Using the preset reference point of the leaf spring as a benchmark, build a suspension frame model that includes the leaf spring reference point, the center position of the bridge tube, the wheel center point, and the ground line. S4. Adjust at least one of the following parameters: vehicle axle load, suspension stiffness, tire parameters, or leaf spring mounting point position parameters. Automatically adjust the wheel center position and ground line through preset correlation to complete the matching of the suspension system and the vehicle attitude.

2. The suspension system adjustment and vehicle attitude matching method according to claim 1, characterized in that, The tire parameters include tire stiffness and tire free radius; the leaf spring parameters include the length of the first leaf spring of the front suspension, the distance between the center of the first leaf spring of the front suspension and the center of the axle tube, the length of the straight section of the front suspension leaf spring, the deflection of the front suspension leaf spring, the stiffness of the front suspension leaf spring, the initial arc height of the front suspension leaf spring, the length of the first leaf spring of the rear suspension and the length of the straight section of the rear suspension leaf spring; the vehicle axle load includes the front suspension load, the rear suspension load, the unsprung mass of the front suspension and the unsprung mass of the rear suspension.

3. The suspension system adjustment and vehicle attitude matching method according to claim 1 or 2, characterized in that, The relationship between the front suspension leaf spring arc height and the axle load satisfies: front suspension leaf spring arc height = initial arc height of front suspension leaf spring - front suspension leaf spring deflection, where front suspension leaf spring deflection = (front suspension leaf spring axle load - front suspension unsprung mass) × 9.8 / (front suspension leaf spring stiffness × 2).

4. The suspension system adjustment and vehicle attitude matching method according to any one of claims 1 to 3, characterized in that, The relationship between the static radius of the tire and the axle load satisfies: Front wheel static radius = tire free radius - front suspension load × 9.8 / (tire stiffness × 2); Rear wheel static radius = tire free radius - rear suspension load × 9.8 / (tire stiffness × 4).

5. The suspension system adjustment and vehicle attitude matching method according to any one of claims 1 to 3, characterized in that, The preset reference point for the leaf spring is the center of the first leaf of the front suspension leaf spring.

6. The suspension system adjustment and vehicle attitude matching method according to any one of claims 1 to 3, characterized in that, When building the suspension frame model, the main leaf springs must satisfy the following constraints: The center points of the front and rear bushings of the leaf spring remain fixed; The lower end of the leaf spring lug moves in an arc around the upper end, with the radius of the movement being the length of the lug. The curved section of the leaf spring remains tangent to the straight section; The total length of the leaf spring remains unchanged; Leaf spring installation angle = (length of the first leaf spring - length of the straight section of the leaf spring) / 2 × 180 × 1 deg / (π × leaf spring radius); Leaf spring radius = (length of the first leaf spring - length of the straight section of the leaf spring) / 2 × 180 × 1 deg / (π × leaf spring installation angle).

7. The suspension system adjustment and vehicle attitude matching method according to any one of claims 1 to 3, characterized in that, In the suspension frame model, the center of the leaf spring main plate is rigidly connected to the wheel center, and a tire profile matching the static radius of the tire is set at the wheel center.

8. The suspension system adjustment and vehicle attitude matching method according to any one of claims 1 to 3, characterized in that, The ground line is obtained by drawing the common tangent of the front and rear tire profiles.

9. The suspension system adjustment and vehicle attitude matching method according to any one of claims 1 to 3, characterized in that, The adjustment parameters include the axle loads of the vehicle under no-load, half-load, and full-load conditions.

10. The suspension system adjustment and vehicle attitude matching method according to any one of claims 1 to 3, characterized in that, The design results output after matching include leaf spring hanger angle, leaf spring hanger point coordinates, wheel center position coordinates, ground line angle, and vehicle attitude angle.

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