Automobile seat system modal analysis method and storage medium

Abstract

The invention discloses an automobile seat system modal analysis method, which comprises seat monomer modal analysis, and the seat monomer modal analysis comprises the following steps: 1) establishing three-dimensional design data of different modalities of a seat; 2) importing three-dimensional design data of a seat mode into software; 3) deleting data irrelevant to the current seat mode; 4) performing data modeling to form a finite element model; 5) according to the actual connection information of the finite element model, selecting a proper connection unit to complete the connection of the finite element model of each part; 6) completing the boundary conditions, completing the simulation model according to the boundary conditions, and submitting the simulation model for calculation; 7) obtaining a solved modal result, importing the result into simulation post-processing software, and identifying the modal frequency and vibration mode of the front seat according to a modal output target; and 8) comparing whether a target is met or not, and obtaining a result report of the modal of the front seat. Through the method, modal analysis of the automobile seat system can be completed, the analysis cost is low, and the accuracy is high.

Description

Technical Field

[0001] The present invention relates to the technical field of passenger car seat system modalities, and in particular to an evaluation method for seat system modalities in a data design phase, and is particularly suitable for modal analysis of seats of passenger cars such as sedans and off-road vehicles. Background Art

[0002] As the automobile industry, especially passenger cars such as sedans and off-road vehicles, shifts from incremental markets to stock markets, the degree of competition has increased dramatically, and vehicle model development has also shifted from performance-driven to experience and scenario-driven. The project development cycle continues to shrink, especially with the development of smart driving and zero-gravity seats. These changes will have an important impact on the seat experience and scenarios. The seat is the core component of the members' human perception. One of the key performance of the seat is comfort. Therefore, modality, as a key parameter of comfort, is becoming more and more important to conduct reasonable examination and evaluation of it during the data design stage. Therefore, advance analysis and testing will be carried out for automotive products that focus on travel, business, etc.

[0003] Conventional seat modes only test normal sitting postures, but cannot test zero-gravity states, multimedia use, or the use of a small table to handle work. This results in development deficiencies, and once problems occur, it is easy to cause customer complaints, which in turn affects the market.

[0004] The current examination of seat installation state modality is based on the interior body TB model of the soft tooling M1 data in the detailed design stage, which cannot meet the industry's actual demand for shorter and shorter development cycles, nor does it reflect the market needs for scenario-based development.

[0005] There are also tests that use a large number of hardware devices, such as the public document with announcement number CN104111156A, publication date 2014-10-22, and patent name "Seat Modal Test Method", which discloses a seat modal test method, including a force hammer, a three-way vibration sensor, a multi-channel vibration and noise test system and a host computer; the three-way vibration sensor and the force hammer are respectively connected to the multi-channel vibration and noise test system, and the multi-channel vibration and noise test system is connected to the host computer; including the following steps: step 1, install the seat to be tested on the floor of the whole vehicle and adjust it to the normal posture; step 2, determine the test point; step 3, install the three-way vibration sensor; step 4, set the test parameters, and select the upper end of the backrest as the excitation position of the force hammer; step 5, select at least 5 frequency response curves and force attenuation curves with good consistency for storage, analyze the test data through the host computer, obtain the frequency response function curve of the seat, and obtain the modal vibration shape of the test seat through modal identification. Similar testing methods have extremely high hardware requirements, and there is no need to increase the initial analysis cost of the car seat. Summary of the invention

[0006] The technical problem to be solved by the present invention is to realize a method for completing the modal analysis of an automobile seat system based on software.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is: a vehicle seat system modal analysis method, the analysis method includes a seat monomer modal analysis, and the seat monomer modal analysis includes the following steps:

[0008] 1) Establish 3D design data of different modes of seats;

[0009] 2) Importing the 3D design data of a seat mode into the software;

[0010] 3) Delete data irrelevant to the current seat mode;

[0011] 4) Data modeling constitutes a finite element model;

[0012] 5) According to the actual connection information of the finite element model, select the appropriate connection unit to complete the connection of the finite element models of each component;

[0013] 6) Complete the boundary conditions, complete the simulation model according to the boundary conditions, and submit the simulation model for calculation;

[0014] 7) Obtain the solved modal results, then import the results into the simulation post-processing software, and identify the frequency and vibration shape of the front seat mode according to the modal output target;

[0015] 8) Compare whether it meets the target and obtain the result report of the front seat mode.

[0016] The seat modes include a zero-gravity posture, a posture in a multimedia use state, a posture in a normal use state of a small table, and a normal sitting posture.

[0017] Data not related to the current seat mode include skin, sponge, standard parts, and the data of the seat frame is retained.

[0018] Data modeling is to separate the parts that need to create finite element meshes from the remaining data, extract the mid-surface of the sheet metal, and complete the finite element mesh model of the seat according to the size and unit type requirements of the solid parts; other parts with no stiffness or low stiffness are simulated by counterweighting and assigned corresponding parameters.

[0019] The boundary conditions are as follows: constraining the degrees of freedom of the seat and the body mounting points, setting the modal analysis conditions, and completing the simulation model.

[0020] The comparison process is to compare the frequency and vibration mode of the current seat mode with the target value. If it is unqualified, it is necessary to conduct optimization analysis based on the strain energy cloud map results of the corresponding mode, combined with cost and cycle, until the goal is achieved.

[0021] The analysis method also includes the seat installation status analysis: under different seat modal conditions of the seat monomer, BIP model analysis and TB model verification are set up, and the BIP model and TB model are completed according to the idea of ​​seat monomer modeling and combined with the specification requirements of the BIP model.

[0022] The BIP model analysis is to remove the constraints of the mounting points in the modal analysis model of the same seat body, assemble it to the BIP model through bolts, perform free modal analysis without constraints, identify the modes of interest of each seat, and compare the results with the target values. If they are unqualified, it is necessary to conduct optimization analysis based on the strain energy results, combined with cost and cycle, until the goal is achieved.

[0023] The TB model verification: the same BIP model is combined with the seat monomer modal analysis model, and the interior and exterior data model is added to achieve the TB model. Free modal analysis is performed without constraints, and the modes of interest of each seat are identified. The results are compared with the target values. If they are unqualified, it is necessary to conduct optimization analysis based on the strain energy results, combined with cost and cycle, until the goal is achieved.

[0024] A storage medium is a computer-readable storage medium for storing software program codes, wherein the software program codes are used to execute the vehicle seat system modal analysis method.

[0025] The present invention is a method for analyzing the modal of a seat system of a car, especially a passenger car such as a sedan, an off-road vehicle, etc., and is specifically embodied in an evaluation method of the seat system modal in the data design stage. The method can be used to complete the modal analysis of the car seat system with low analysis cost and high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The following is a brief description of the contents expressed in each figure in the specification of the present invention:

[0027] Figure 1 It is the X-direction mode of the driver's seat;

[0028] Figure 2 Analyze the X-direction mode of the seat for the BIP model;

[0029] Figure 3 Analyze the X-direction mode of the seat for TB model verification. DETAILED DESCRIPTION

[0030] The following is a further detailed description of the specific implementation methods of the present invention, such as the shape, structure, relative position and connection relationship between the various components involved, the function and working principle of each part, the manufacturing process and operation method, etc., through the description of the embodiments with reference to the accompanying drawings, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention.

[0031] The seat system modal analysis method mainly includes the seat monomer modal analysis and seat installation status;

[0032] Modal analysis of seat units: Based on the normal sitting posture modality, we add modalities in multiple scenarios such as zero-gravity posture, multimedia use, and normal use of small tables, so that we can truly start from the experience, take the user as the center, build long boards in scenarios, and enhance product competitiveness. For example, in the zero-gravity scenario, customers are mainly in a resting state, and the core demand at this time is comfort. At this time, most people need air conditioning, multimedia and other equipment to work normally, so the modality is the basic indicator of comfort;

[0033] Seat installation status analysis: The seat modal examination is advanced from the interior body TB model of the soft tooling M1 data in the detailed design stage to the BIP model of the overall class analysis M0 data in the preliminary design stage. The analysis scenario is the same as the seat monomer modal examination item in 1). It can provide greater help for the development of seats and better meet users' needs and pursuit of seat comfort, thereby enhancing the market competitiveness of products. Verified by multiple models: the TB model results under M1 data are about 0.5Hz lower than the BIP results of the same modal frequency value of the seat, and the accuracy can meet engineering requirements.

[0034] The following is a detailed description of the two-step analysis method:

[0035] 1. Modal analysis of the seat monomer. Before starting this step, you need to receive the correct three-dimensional design data of the seat in normal sitting posture, zero gravity and other scene states from the professional department. The data needs to be designed. The data of different models are different. The scene state can also be designed in advance according to needs. Generally, it is the state of the vehicle, including but not limited to normal sitting posture, zero gravity sitting posture, multimedia entertainment state sitting posture, etc. The three-dimensional design data of the seat for each sitting posture is different and needs to be submitted for sorting. After the data design is completed, perform the following steps:

[0036] 1) Import the data into the finite element pre-processing software, which is an existing modeling software. Each imported data is one of the postures of the seat. For example, first import the 3D design data of the seat in the normal sitting posture. After completing all the steps below, import the 3D design data and information of the seat in the next posture.

[0037] The 3D seat design data is imported into the software, and then the skin, sponge, standard parts and other components that are not related to the modal analysis are deleted according to CAE theory, standards and specifications. According to different seat material categories, the seat materials need to be classified and defined in advance. After the data is imported, the data that is not related to the current analyzed mode will be automatically deleted according to the definition. The remaining data is the data required for simulation, such as retaining the skeleton and other data required for simulation;

[0038] 2) Separate the parts that need to create finite element meshes from the remaining data after deletion (such as skin, sponge, standard parts, etc.), process the sheet metal data separately, extract the mid-surface of the sheet metal, and complete the finite element mesh model of the seat according to the size and unit type requirements;

[0039] 3) The stiffness information of each seat component will also be defined in advance. In this step, the data of components with no stiffness or low stiffness are simulated by weighting according to the pre-defined information, and the corresponding parameters are assigned. The assigned parameters are pre-selected and calibrated according to the vehicle information;

[0040] 4) Combining the above three steps, after adjusting the various parameter information, the finite element model created in the software is selected according to the actual connection information to complete the connection of the finite element models of each component;

[0041] 5) There will be boundary problems during the connection process. The boundaries are handled by conditional constraints, that is, constraining the degrees of freedom of the seat and body installation points, setting modal analysis conditions, and completing the simulation model based on the above parameter design. Click Submit in the software, and the software will perform calculations based on the modeling data;

[0042] 6) The calculation results will be automatically displayed. The modal result files after solution will be downloaded. Generally, these data will be transferred and stored for later reuse and convenient re-verification of experimental data. The calculation results need to be imported into simulation again and processed by simulation software. The simulation software will identify the frequency and vibration mode of each mode of interest of each seat according to the modal output target;

[0043] 7) Compare the frequency and vibration type results of the current posture analysis with the target value. The target value is the pre-designed optimal value, generally an interval value. The comparison process is a simple data comparison. If the analyzed data is in the interval value, the more centered it is, the better the result. If the result is outside the target value interval, it is defined as unqualified. If it is unqualified, it is necessary to carry out optimization analysis based on the strain energy cloud diagram results of the corresponding mode, combined with cost, cycle, etc., until the goal is achieved;

[0044] 8) Finally, complete the seat modal result report output, such as Figure 1The X-direction mode of the driver's seat shown in the figure is a normal sitting posture analysis. If it is necessary to obtain the analysis of other postures, then process it according to the above steps to obtain the seat monomer modal analysis results for each posture of the car seat.

[0045] 2. Seat installation status mode:

[0046] In the normal sitting posture, zero gravity and other scenes with the seat monomer modal working conditions, BIP model analysis and TB model (soft tooling version data and frozen version data) verification are required for each working condition. According to the idea of ​​seat monomer modeling and combined with the specification requirements of the BIP model, the BIP model and TB model are completed. The following is a detailed explanation of the BIP model analysis and TB model (soft tooling version data and frozen version data) verification as follows:

[0047] 1) Analysis of BIP model

[0048] This analysis method first removes the constraints of the mounting points in the modal analysis model of the same seat monomer, assembles it to the BIP model through bolts, and performs free modal analysis without constraints. Then, the modes of interest of each seat are obtained through analysis, and the results (each mode of interest) are compared with the target value. Similarly, the target value also needs to be pre-designed according to the seat BIP model analysis of the vehicle model to be analyzed. The target value obtained is obtained in the form of interval values ​​as much as possible. During the comparison process, the comparison process is a simple data comparison. If the analyzed data is in the interval value, the more centered it is, the better the result. If the result is outside the target value interval, it is defined as unqualified. If it is unqualified, it is necessary to carry out optimization analysis based on the strain energy results, combined with cost, cycle, etc. This analysis step is a manual adjustment step and is not within the scope of the present invention. The analysis parameters are adjusted each time until the target is achieved, that is, the analyzed data is in the preset target value interval. Figure 2 The X-mode of the driver's seat is shown:

[0049] 2) TB model validation analysis

[0050] This verification method first adds other interior and exterior data models to the same BIP model + seat monomer modal analysis model to achieve a TB (soft tooling version data and frozen version data) model, and performs free modal analysis without constraints. The soft tooling version data and frozen version data are pre-defined based on the vehicle model and configuration. If there are variables in the seat configuration, such as using different soft packages, the verification steps need to be completed independently for different configurations. After that, the modes of interest of each seat are identified based on the analysis results, and the results are compared with the target values. Similarly, the target value is also required to be verified based on the pre-selected design of the seat TB model of the vehicle model to be verified. The target value obtained is obtained as much as possible in the form of interval values. During the comparison process, the comparison process is a simple data comparison. If the analyzed data is in the interval value, the more centered it is, the better the result. If the result is outside the target value interval, it is defined as unqualified. If it is unqualified, it is necessary to conduct optimization analysis based on the strain energy results, combined with cost, cycle, etc. until the goal is achieved. Figure 3 The driver's seat X-mode is shown.

[0051] Based on the above-mentioned automotive seat system modal analysis method, it can be applied to conventional passenger vehicles, such as sedans, off-road vehicles, etc., to analyze the seats of passenger vehicles, so as to obtain the optimal seat configuration scheme. The above-mentioned software method is stored in the form of program code, which is stored in a storage medium. The storage medium is a computer-readable storage medium for storing software program codes. The software program code is used to execute the above-mentioned automotive seat system modal analysis method. The storage medium is generally a computer storage hard disk, and the computer is used to cooperate with a keyboard, mouse, display, CPU, motherboard, etc. to realize functions. In the implementation process, other software can also be used to complete more functions.

[0052] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A modal analysis method for a vehicle seat system, characterized in that: The analysis method includes a seat monomer modal analysis, and the seat monomer modal analysis includes the following steps: 1) Establish 3D design data of different modes of seats; 2) Importing the 3D design data of a seat mode into the software; 3) Delete data irrelevant to the current seat mode; 4) Data modeling constitutes a finite element model; 5) According to the actual connection information of the finite element model, select the appropriate connection unit to complete the connection of the finite element models of each component; 6) Complete the boundary conditions, complete the simulation model according to the boundary conditions, and submit the simulation model for calculation; 7) Obtain the solved modal results, then import the results into the simulation post-processing software, and identify the frequency and vibration shape of the front seat mode according to the modal output target; 8) Compare whether it meets the target and obtain the result report of the front seat mode.

2. The automotive seat system modal analysis method according to claim 1, characterized in that: The seat modes include a zero-gravity posture, a posture in a multimedia use state, a posture in a normal use state of a small table, and a normal sitting posture.

3. The automotive seat system modal analysis method according to claim 2, characterized in that: Data not related to the current seat mode include skin, sponge, standard parts, and the data of the seat frame is retained.

4. The automotive seat system modal analysis method according to claim 3, characterized in that: Data modeling is to separate the parts that need to create finite element meshes from the remaining data, extract the mid-surface of the sheet metal, and complete the finite element mesh model of the seat according to the size and unit type requirements of the solid parts; other parts with no stiffness or low stiffness are simulated by counterweighting and assigned corresponding parameters.

5. The automotive seat system modal analysis method according to claim 4, characterized in that: The boundary conditions are as follows: constraining the degrees of freedom of the seat and the body mounting points, setting the modal analysis conditions, and completing the simulation model.

6. The automotive seat system modal analysis method according to claim 5, characterized in that: The comparison process is to compare the frequency and vibration mode of the current seat mode with the target value. If it is unqualified, it is necessary to conduct optimization analysis based on the strain energy cloud map results of the corresponding mode, combined with cost and cycle, until the goal is achieved.

7. The vehicle seat system modal analysis method according to any one of claims 1 to 6, characterized in that: The analysis method also includes the seat installation status analysis: under different seat modal conditions of the seat monomer, BIP model analysis and TB model verification are set up, and the BIP model and TB model are completed according to the idea of ​​seat monomer modeling and combined with the specification requirements of the BIP model.

8. The automotive seat system modal analysis method according to claim 7, characterized in that: The BIP model analysis is to remove the constraints of the mounting points in the modal analysis model of the same seat body, assemble it to the BIP model through bolts, perform free modal analysis without constraints, identify the modes of interest of each seat, and compare the results with the target values. If they are unqualified, it is necessary to conduct optimization analysis based on the strain energy results, combined with cost and cycle, until the goal is achieved.

9. The automotive seat system modal analysis method according to claim 8, characterized in that: The TB model verification: the same BIP model is combined with the seat monomer modal analysis model, and the interior and exterior data model is added to achieve the TB model. Free modal analysis is performed without constraints, and the modes of interest of each seat are identified. The results are compared with the target values. If they are unqualified, it is necessary to conduct optimization analysis based on the strain energy results, combined with cost and cycle, until the goal is achieved.

10. A storage medium, the storage medium being a computer-readable storage medium for storing software program codes, characterized in that: The software program code is used to execute the vehicle seat system modal analysis method as described in any one of claims 1-9.

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