A method for generating motion envelope of suspension system
By generating the motion envelope of the suspension system, the problem of difficulty in identifying whether the design space meets the performance requirements in the design of suspension system components is solved, achieving more accurate design evaluation and improving efficiency.
Patent Information
- Application Number
- CN202210111394.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-01-29
- Publication Date
- 2025-01-21
- Estimated Expiration
- 2042-01-29
AI Technical Summary
The existing suspended system component design is difficult to accurately identify whether the reserved design space of the structure meets the performance requirements, resulting in performance parameters deviating from the design goals and increasing the risk of later design changes.
A method for generating the motion envelope of the suspension system is proposed. By collecting the digital and analog parameters of the powertrain and the suspension system, the components are divided into fixed-type and tie-rod types, and the motion envelope of each component is generated respectively, and then Obtain the motion envelope of the suspension system.
By generating the motion envelope of the suspension system, component gaps and internal structures can be evaluated more accurately, reducing design redundancy, avoiding collision risks in advance, improving design efficiency, and reducing the risk of later design changes.
Smart Images
Figure CN114462148B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to a suspension system, and in particular to a method for generating a motion envelope of a suspension system. Background Art
[0002] The suspension system is a very important component in the car. It is responsible for fixing the powertrain, attenuating the vibration of the powertrain, and limiting the displacement of the powertrain. The performance of the suspension system is strongly related to the NVH performance of the whole vehicle. However, in fact, the design of the suspension system components is affected by the powertrain, body, chassis and other related components. The layout position and design space of the suspension system are greatly restricted, squeezing the design space of the vibration isolation rubber. As a result, it is impossible to identify whether the design space reserved by the structure of the suspension system components can meet the necessary performance requirements during the component design stage, which in turn causes the performance parameters of the suspension system suspension cushion, especially the performance parameters in the nonlinear area, to deviate from the design target, and the risk of later design changes is high.
[0003] The structural design of the vibration isolation rubber of the current suspension system is basically based on the reference to the existing suspension structure, combined with the specific performance target for the initial design, and then the CAE analysis is carried out to determine whether the performance target is achieved according to the CAE analysis results. However, this method has the following problems: First, the reserved value of the gap between the suspension system components and the surrounding is judged based on the empirical value in the early stage, and there may be over-design or under-design; second, CAE analysis cannot identify whether there is a collision risk inside the suspension system components; third, this method requires continuous optimization and adjustment of the suspension structure according to the CAE analysis results, which is a large workload, a long processing cycle, and low efficiency. Summary of the invention
[0004] The object of the present invention is to provide a method for generating a motion envelope of a suspension system, so as to alleviate or eliminate at least one of the above-mentioned technical problems.
[0005] The method for generating a motion envelope of a suspension system according to the present invention comprises the following steps:
[0006] Collect digital and analog parameters of powertrain and suspension systems;
[0007] The various suspension system components are divided into tie-rod suspension system components and fixed-connection suspension system components fixedly connected to the powertrain, and motion envelopes are generated for the tie-rod suspension system components and the fixed-connection suspension system components respectively;
[0008] The method for generating the motion envelope of each fixed suspension system component comprises the following steps:
[0009] Under static load conditions, a powertrain reference coordinate system is established at the center of mass of the powertrain. The extreme positions of the powertrain reference coordinate system under each condition are simulated and calculated using simulation software to obtain the powertrain target coordinate system under each condition. The models of each fixed-type suspension system component in the powertrain reference coordinate system are transformed to the powertrain target coordinate system using coordinate transformation to obtain the extreme positions of each fixed-type suspension system component under each condition, thereby generating the motion envelope of each fixed-type suspension system component.
[0010] The motion envelope generation method of each tie rod suspension system component comprises the following steps:
[0011] A tie rod reference coordinate system is established at a point on each tie rod type suspension system component, and the limit position of the tie rod reference coordinate system under each working condition is simulated and calculated by using simulation software, and the tie rod target coordinate system under each working condition is obtained. The models of each tie rod type suspension system component in the tie rod reference coordinate system are transformed to the tie rod target coordinate system by using coordinate transformation, and the limit position of each tie rod type suspension system component under each working condition is obtained, thereby generating the motion envelope of each tie rod type suspension system component;
[0012] The motion envelope of the suspension system is obtained according to the motion envelope of each fixed suspension system component and the motion envelope of each tie rod suspension system component.
[0013] Optionally, the tie rod reference coordinate system is established at the elastic center point of the small head of each tie rod type suspension system component.
[0014] Optionally, the process of establishing the tie rod reference coordinate system includes the following steps: selecting a first reference point and a second reference point on each tie rod suspension system component, using the first reference point as the origin of the tie rod reference coordinate system, and using the line connecting the first reference point and the second reference point as a coordinate axis of the tie rod reference coordinate system.
[0015] Optionally, the first reference point is the elastic center point of the small end of each component of the pull-rod type suspension system, and the second reference point is the elastic center point of the large end of each component of the pull-rod type suspension system.
[0016] Optionally, the motion envelope of the suspension system is parameterized and modeled in simulation software.
[0017] Optionally, the simulation software is CATIA software.
[0018] The present invention can generate a motion envelope of the suspension system, and can use the motion envelope of the suspension system to more accurately evaluate the gap values between the suspension system components and the surrounding components, thereby reducing design redundancy; the motion envelope of the suspension system can be used to more accurately evaluate the gaps in the internal structures of the suspension system components, thereby avoiding the risk of internal collision in advance and reducing later design changes; the motion envelope of the suspension system can be used to evaluate the anti-collision limit structure of the suspension system components, and the possibility of the suspension structure achieving the suspension performance curve can be evaluated in advance, and the suspension structure can be adjusted in advance, thereby reducing the number of CAE analyses and improving work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 is a flow chart of a method for generating a motion envelope of a suspension system described in a specific implementation manner;
[0020] Figure 2 Specific working condition table for matching suspension parameters;
[0021] Figure 3 Generate the required relevant parameter table for the suspension motion envelope;
[0022] Figure 4 The method for the powertrain target coordinate system is illustrated;
[0023] Figure 5 Schematic diagram of the extreme positions of the components of the fixed suspension system under working condition 30;
[0024] Figure 6 The motion envelope of the components of the fixed suspension system under 43 working conditions;
[0025] Figure 7 This is a schematic diagram of a common suspension installation structure;
[0026] Figure 8 It is a schematic diagram of common tie rod type suspension system components;
[0027] Fig. 9 It is a schematic diagram of the positions of the components of the tie rod type suspension system under working condition 30;
[0028] Fig.10 It is a schematic diagram of the motion envelope of the components of the tie rod suspension system;
[0029] Fig.11 For model and design tables;
[0030] Fig.12 is an auxiliary table;
[0031] Fig.13 Schematic diagram of using the suspension motion envelope to check the clearance between the suspension components and surrounding components;
[0032] Fig.14 Schematic diagram of using the suspension motion envelope to inspect the internal structure of the suspension components;
[0033] Fig.15 Schematic diagram of using the suspension motion envelope to evaluate the suspension anti-collision limit block structure. DETAILED DESCRIPTION
[0034] The present invention will be further described below in conjunction with the accompanying drawings.
[0035] In order to explain the method of generating the motion envelope of the suspension system in detail, the following mainly focuses on Figure 2 The envelope generation is described by taking the 30th working condition in (hereinafter referred to as working condition 30) as an example.
[0036] like Figure 1 A method for generating a motion envelope of a suspension system is shown, comprising the following steps:
[0037] S1. Collect the digital and analog parameters of the powertrain and suspension system to provide a basis for subsequent simulation analysis. The digital and analog parameters of the powertrain and suspension system include but are not limited to structural parameters, material parameters and motion parameters. The digital and analog parameters of the powertrain and suspension system can be obtained through measurement and testing. Based on the collected digital and analog parameters of the powertrain and suspension system, modeling is performed in the simulation software to match the powertrain and suspension system parameters.
[0038] S2. Divide each suspension system component into a tie rod suspension system component and a fixed suspension system component fixedly connected to the powertrain, and generate motion envelopes for the tie rod suspension system components and the fixed suspension system components respectively. By generating motion envelopes separately, a more accurate motion envelope can be generated. Figure 7 As shown, a common suspension installation structure includes a subframe 5, a powertrain 6, a connecting bracket 7, a connecting bolt 8 and a suspension rod 9. The connecting bracket 7 is fixedly connected to the powertrain 6, one end of the suspension rod 9 is connected to the connecting bracket 7 by a connecting bolt 8, and the other end of the suspension rod 9 is connected to the subframe 5. Both ends of the suspension rod 9 are provided with buffer bushings. The fixed suspension system components move with the powertrain, such as the above-mentioned connecting bracket 7. In this embodiment, the fixed suspension system components are described by taking the connecting bracket 7 as an example. The tie rod type suspension system components are connected to the powertrain using a tie rod structure. One end of the tie rod type suspension system components moves with the powertrain and the other end is subject to certain restrictions, such as the above-mentioned suspension rod 9. In this embodiment, the tie rod type suspension system components are described by taking the suspension rod 9 as an example.
[0039] The method for generating the motion envelope of each fixed suspension system component comprises the following steps:
[0040] S211, such as Figure 4 and Figure 5 As shown, a powertrain reference coordinate system 2 is established at the center of mass of the powertrain under static load conditions, and the extreme position 4 of the powertrain under working condition 30 is simulated and calculated using simulation software to obtain the translation and rotation of the powertrain. According to the translation and rotation of the powertrain under working condition 30, the powertrain reference coordinate system 2 is translated along the X, Y, and Z directions and rotated around the X, Y, and Z axes by corresponding amounts, and the powertrain reference coordinate system 2 is moved to the extreme position, thereby obtaining the powertrain target coordinate system 3 under working condition 30.
[0041] S212, using coordinate transformation, transform the model of the fixed-mount system component in the powertrain reference coordinate system 2 to the powertrain target coordinate system 3, output the result, and obtain the extreme position of the fixed-mount system component 1 under the working condition 30.
[0042] S213, in Figure 2 Under the 43 working conditions shown in FIG. 1 , steps S211 and S212 are repeated respectively to obtain the limit positions of the fixed suspension system component 1 under the 43 working conditions, thereby obtaining the motion envelope of the fixed suspension system component 1. The motion envelope of the fixed suspension system component 1 is shown in FIG. Figure 6 shown.
[0043] By executing steps S211, S212 and S213 for each fixed suspension system component 1, the motion envelope of each fixed suspension system component 1 can be obtained. In specific implementation, each fixed suspension system component 1 can also be processed as a whole for simulation analysis, which can improve the efficiency of simulation analysis.
[0044] The motion envelope generation method of each tie rod suspension system component comprises the following steps:
[0045] S221, establish a tie rod reference coordinate system at a point on the tie rod suspension system component 10, the tie rod reference coordinate system is usually established at the elastic center point of the small end of the tie rod suspension system component 10. In specific implementation, Figure 8As shown, a first reference point 11 and a second reference point 12 are selected on the tie-rod suspension system component 10, the first reference point 11 is used as the origin of the tie-rod reference coordinate system, the line connecting the first reference point 11 and the second reference point 12 is used as the X-axis of the tie-rod reference coordinate system, the Y-axis of the vehicle coordinate system is used as the Y-axis of the tie-rod reference coordinate system, and the Z-axis of the reference coordinate system is determined by the right-hand rule; theoretically, any two points on the tie-rod suspension system component 10 can be used as reference points, but in order to be associated with the suspension matching calculation results, the elastic center point of the small end of the tie-rod suspension system component 10 is usually selected as the first reference point 11, and the elastic center point of the large end of the tie-rod suspension system component 10 is selected as the second reference point 12.
[0046] S222, such as Figure 8 and Fig. 9 As shown, the limit positions of the tie rod suspension system component 10 under working condition 30 are simulated and calculated using simulation software, and the position 15 of the tie rod suspension system component 10 under static load and the limit position 16 of the tie rod suspension system component 10 under working condition 30 are obtained, and the limit position 13 of the first reference point and the limit position 14 of the second reference point are obtained. In theory, the elastic center point of the small head can also be regarded as a point on the connecting bracket. As the powertrain moves together, the position of the elastic center point of the small head under certain working conditions can be obtained by coordinate transformation through the transformed powertrain target coordinate system. Therefore, the translation amount of the tie rod small head of the tie rod suspension system component is not a necessary input parameter for envelope production. First, translate the origin of the tie rod reference coordinate system to the extreme position 13 of the first reference point, and then use the extreme position 13 of the first reference point as the hinge point to align the X-axis direction of the tie rod reference coordinate system to the extreme position 14 of the second reference point (this transformation requires that the coordinate system does not rotate around the X-axis), and obtain the extreme position of the tie rod reference coordinate system, that is, the tie rod target coordinate system under working condition 30.
[0047] S223. Use coordinate transformation to transform the model of the tie-rod suspension system components in the tie-rod reference coordinate system to the tie-rod target coordinate system, output the result, and obtain the extreme position of the tie-rod suspension system components under working condition 30.
[0048] S224, in Figure 2 Under the 43 working conditions shown in FIG. 1 , steps S221, S222 and S223 are repeated respectively to obtain the limit positions of the components of the tie rod type suspension system under the 43 working conditions, thereby obtaining the motion envelope of the components of the tie rod type suspension system. The motion envelope of the components of the tie rod type suspension system is shown in FIG. Fig.10 shown.
[0049] Steps S221, S222, S223 and S224 are respectively performed for each component of the pull-rod suspension system to obtain the motion envelope of each component of the pull-rod suspension system.
[0050] S3. Obtaining a suspension system motion envelope according to the motion envelopes of the components of the fixed-connection suspension system and the motion envelopes of the components of the pull-rod suspension system.
[0051] Furthermore, in order to facilitate simulation calculation, the relevant information required for the generation of the suspension motion envelope can be made into Figure 3 The parameter table shown can be used to record data and input data according to the data in the table during the simulation calculation process.
[0052] Since the suspension system has many matching calculation conditions, the amount of data is relatively large, and many parts are involved, if the motion envelope of each part is generated by 3D simulation software according to the above suspension system motion envelope generation method, the workload is undoubtedly huge. As an improved solution, in order to obtain the suspension system motion envelope more quickly, the parametric modeling function and input interface of the 3D simulation software are used to realize a fast generation of motion envelope. The following takes CATIA software as an example to illustrate the fast generation method of the envelope of the pull rod suspension system parts:
[0053] S41, such as Fig.11 As shown, the envelope modeling of all the components of the pull-rod suspension system is completed, and the envelope model tree 17, the component model 18 that needs to be enveloping operation, the design table 19 and the parameter correspondence 20 between the design table and the component model are obtained, and the design table 19 is exported.
[0054] S42, such as Fig.12 As shown, an auxiliary table is created to expand the original data into a column according to the row, so that the data column corresponds to and is associated with the design table 19.
[0055] S43, update the parameter value in the auxiliary table, update Fig.11 The component model that needs to be calculated is 18.
[0056] S44. Refresh the entire model to quickly obtain the motion envelope of the new operation object.
[0057] After obtaining the motion envelope of the suspension system, the motion envelope of the suspension system can be used to inspect the suspension components, such as Fig.13 As shown in the figure, the suspension system motion envelope can be used to check the clearance between components and surrounding components to avoid external motion interference and improve design accuracy. The suspension system motion envelope can be used to check the internal structure of the suspension to ensure that the relative moving parts retain a safe gap and avoid internal motion interference. Fig.14As shown in the figure, there is a risk of interference inside the components of the tie rod suspension system, and the structure needs to be changed or the suspension performance parameters need to be adjusted. The suspension system motion envelope can be used to check the structure of the suspension's anti-collision limit block to make the suspension structure more accurate and reasonable, and improve the overlap between the early design and the suspension performance curve. Fig.15 As shown, the motion envelope of the suspension system can be used to evaluate the structure of the suspension anti-collision block, and the core shaft position 21 under static load conditions, the core shaft position 22 under a certain condition, the compression amount of the anti-collision limit block under a certain condition 23, the design height of the anti-collision limit block 24, the design curve of a certain suspension 25 and the design working point 26 of a certain suspension under a certain condition are obtained. The design curve of a certain suspension shows that under this condition, the suspension should be approximately 40% of the nonlinear region (excluding the length of the linear segment), considering that the rubber has approximately 60% of the compressible space, and according to the design stiffness curve, the suspension anti-collision limit block is compressed by approximately 24% under this condition; however, the motion envelope of the suspension system shows that the compression rate of the anti-collision limit block of the suspension of this structure under this condition is approximately 40%, which means that the structure of this suspension is not consistent with the design stiffness curve of this suspension, and corresponding adjustments should be made.
Claims
1. A method for generating a motion envelope of a suspension system, characterized in that: The following steps are involved: Collect digital and analog parameters of powertrain and suspension systems; The various suspension system components are divided into tie-rod suspension system components and fixed-connection suspension system components fixedly connected to the powertrain, and motion envelopes are generated for the tie-rod suspension system components and the fixed-connection suspension system components respectively; The method for generating the motion envelope of each fixed suspension system component comprises the following steps: Under static load conditions, a powertrain reference coordinate system is established at the center of mass of the powertrain. The extreme positions of the powertrain reference coordinate system under each condition are calculated by simulation software, and the powertrain target coordinate system under each condition is obtained. The models of each fixed-type suspension system component in the powertrain reference coordinate system are transformed to the powertrain target coordinate system by coordinate transformation, and the extreme positions of each fixed-type suspension system component under each condition are obtained, thereby generating the motion envelope of each fixed-type suspension system component. The motion envelope generation method of each tie rod suspension system component comprises the following steps: A tie rod reference coordinate system is established at a point on each tie rod type suspension system component, and the limit position of the tie rod reference coordinate system under each working condition is simulated and calculated by using simulation software, and the tie rod target coordinate system under each working condition is obtained. The models of each tie rod type suspension system component in the tie rod reference coordinate system are transformed to the tie rod target coordinate system by using coordinate transformation, and the limit position of each tie rod type suspension system component under each working condition is obtained, thereby generating the motion envelope of each tie rod type suspension system component; Obtaining a suspension system motion envelope according to the motion envelopes of each fixed suspension system component and the motion envelopes of each tie rod suspension system component; After obtaining the motion envelope of the suspension system, use the motion envelope of the suspension system to check the gap between the suspension components and surrounding components, use the motion envelope of the suspension system to check the internal structure of the suspension, and use the motion envelope of the suspension system to check the structure of the anti-collision limit block of the suspension.
2. The method for generating a suspension system motion envelope according to claim 1, characterized in that: The tie rod reference coordinate system is established at the elastic center point of the small head of each tie rod suspension system component.
3. The method for generating a suspension system motion envelope according to claim 1, characterized in that: The process of establishing the tie rod reference coordinate system includes the following steps: A first reference point and a second reference point are selected on each tie rod suspension system component, the first reference point is used as the origin of the tie rod reference coordinate system, and the line connecting the first reference point and the second reference point is used as a coordinate axis of the tie rod reference coordinate system.
4. The method for generating a suspension system motion envelope according to claim 3, characterized in that: The first reference point is the elastic center point of the small end of each component of the pull-rod type suspension system, and the second reference point is the elastic center point of the large end of each component of the pull-rod type suspension system.
5. The method for generating a suspension system motion envelope according to claim 1, characterized in that: The motion envelope of the suspension system is parametrically modeled in the simulation software.
6. The method for generating a suspension system motion envelope according to claim 5, characterized in that: The simulation software is CATIA software.