Automobile seat system modal analysis method and storage medium

Abstract

The application discloses a kind of automobile seat system modal analysis methods, analysis method includes seat single body modal analysis, and the seat single body modal analysis includes the following steps: 1) establishing the three-dimensional design data of different seat modes;2) the three-dimensional design data of a seat mode is imported into software;3) delete the data irrelevant to current seat mode;4) data modeling constitutes finite element model;5) according to the actual connection information of finite element model, select appropriate connection unit to complete the connection of each component finite element model;6) complete boundary condition, according to boundary condition, complete simulation model, and submit calculation to simulation post-processing software;7) obtain the modal result after solving, then the result is imported into simulation post-processing software, according to modal output target, identify the frequency and vibration mode of front seat mode;8) compare whether it meets target, obtain the result report of front seat mode. Through the method, automobile seat system modal analysis can be completed, the analysis cost is low and the accuracy is high.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of passenger car seat system modal technology, in particular to a method for evaluating seat system modal in the data design stage, and is particularly suitable for modal analysis of passenger car seats such as cars and off-road vehicles. BACKGROUND

[0002] With the transition of the passenger car industry, especially cars and off-road vehicles, from the incremental market to the stock market, the degree of competition has increased dramatically, and the development of vehicle models has also changed from performance-oriented to experience development and scene development. The project development cycle continues to be compressed, especially with the development of intelligent driving and zero-gravity seats. These changes will have a significant impact on the use experience and scene of the seat, and the seat is the core component of human perception for members. One of the key performance indicators for evaluating seats is comfort. Therefore, it is becoming increasingly important to reasonably examine and evaluate modal as a key parameter of comfort in the data design stage. Therefore, car products that focus on travel and business will be analyzed in advance.

[0003] Conventional seat modal only examines normal sitting posture, and cannot examine the state of zero-gravity, using multimedia or using a small desk to handle work matters, resulting in a development gap. Once a problem occurs, it can easily cause customer complaints and affect the market.

[0004] Current seat installation state modal examination is conducted on the interior body TB model of soft tooling M1 data in the detailed design stage, which cannot meet the increasingly short development cycle requirements of the industry, and also fails to meet the needs of the market for scene-based development.

[0005] There are also tests using a large number of hardware devices, such as the publication number CN104111156A, published on October 22, 2014, and the patent name "Seat Modal Test Method", which discloses a seat modal test method, including a force hammer, a three-direction vibration sensor, a multi-channel vibration noise test system, and an upper computer. The three-direction vibration sensor and the force hammer are connected to the multi-channel vibration noise test system, and the multi-channel vibration noise test system is connected to the upper computer. The steps include: step one, installing the measured seat on the vehicle floor and adjusting it to the normal position; step two, determining the test points; step three, installing the three-direction vibration sensor; step four, setting the test parameters, selecting the upper end of the backrest as the excitation position of the force hammer; step five, selecting at least 5 consistent frequency response curves and force decay curves for saving, analyzing the test data through the upper computer to obtain the frequency response function curve of the seat, and obtaining the modal vibration mode of the test seat through modal identification. Similar test methods have high hardware requirements, which increase the cost of early analysis of car seats. SUMMARY

[0006] The technical problem solved by the present application is to realize a software-based automobile seat system modal analysis method.

[0007] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows: an automobile seat system modal analysis method, the analysis method comprising seat single body modal analysis, the seat single body modal analysis comprising the following steps:

[0008] 1) establishing three-dimensional design data of different modes of a seat;

[0009] 2) importing three-dimensional design data of a seat mode into software;

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

[0011] 4) data modeling to form a finite element model;

[0012] 5) selecting appropriate connection units to complete the connection of finite element models of various parts according to actual connection information of the finite element model;

[0013] 6) completing boundary conditions, completing a simulation model according to the boundary conditions, and submitting the simulation model for calculation;

[0014] 7) obtaining a modal result after solving, importing the result into simulation post-processing software, identifying the frequency and mode shape of the front seat mode according to the modal output target;

[0015] 8) comparing whether it meets the target to obtain a result report of the front seat mode.

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

[0017] The data irrelevant to the current seat mode comprises a skin, a sponge, and a standard part, and the data of a seat skeleton is reserved.

[0018] Data modeling is to separate parts requiring the creation of a finite element grid from the remaining data, extract the surface of sheet metal, and complete the finite element grid model of the seat according to the size and unit type requirements; the data of other parts with no or small stiffness is simulated by means of counterweight and is given corresponding parameters.

[0019] The boundary conditions: constrain the freedom degrees of the seat and the mounting point of the vehicle body, set the modal analysis working condition, and complete the simulation model.

[0020] The comparison process is to compare the frequency and mode shape of the current seat mode with the target value; if it is unqualified, optimization analysis needs to be carried out according to the strain energy cloud result of the corresponding mode, combined with the cost and cycle, until the target is achieved.

[0021] The analysis method also includes the seat installation state analysis: under different seat modal conditions of individual seats, BIP model analysis and TB model verification are set up. Following the idea of ​​individual seat modeling and in combination with the specification requirements of BIP model, BIP model and TB model are completed.

[0022] The BIP model analysis involves removing the constraints of the mounting points in the modal analysis model of the same seat unit, assembling it onto the BIP model with bolts, and performing free modal analysis without constraints. This identifies the modes of interest for each seat, compares the results with the target values, and if they are not satisfactory, optimization analysis needs to be carried out based on the strain energy results, combined with cost and cycle time, until the target is achieved.

[0023] The TB model verification involves combining the same BIP model with the seat unit modal analysis model and adding interior and exterior trim data models to achieve the TB model. Unconstrained free modal analysis is then performed to identify the modes of interest for each seat. The results are compared with the target values. If the results are not satisfactory, optimization analysis is required based on the strain energy results, combined with cost and cycle time, until the target is achieved.

[0024] A storage medium, wherein the storage medium is a computer-readable storage medium for storing software program code, characterized in that: the software program code is used to execute the modal analysis method for the automotive seat system.

[0025] This invention provides a method for analyzing the modal characteristics of automotive seating systems, particularly passenger vehicles such as sedans and SUVs. Specifically, it is an evaluation method for seating system modal characteristics during the data design phase. This method can perform automotive seating system modal analysis with low cost and high accuracy. Attached Figure Description

[0026] The following is a brief explanation of the content represented by each figure in this specification:

[0027] Figure 1 For the driver's seat X-direction mode;

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

[0029] Figure 3 The X-direction modality of the seat was analyzed to validate the TB model. Detailed Implementation

[0030] The specific embodiments of the present application are described below with reference to the accompanying drawings, which show, by way of illustration, the details of various configurations, arrangements, mutual positions and connection relationships between parts, the functions and working principles of the parts, manufacturing processes and operation and use methods, and the like, to help those skilled in the art have a more complete, accurate and in-depth understanding of the inventive concept and technical solutions of the present application.

[0031] The analysis method of the seat system mode mainly includes seat monomer mode analysis and seat installation state;

[0032] Seat monomer mode analysis: on the basis of normal sitting mode, modes in multiple scenes such as zero-gravity posture, multimedia use state and normal use of small table board are added, which can truly start from experience, take users as the center, create long boards in a scene, and enhance product competitiveness. For example, the zero-gravity scene, at this time the customer is mainly in a resting state, the core demand at this time is comfort, and at this time most of the air conditioners, multimedia and other equipment need to be in a normal working state, so the mode is the basic index of comfort;

[0033] Seat installation state analysis: the examination of seat mode is carried out in advance from the interior body TB model of soft tooling M1 data in the detailed design stage to the BIP model of overall analysis M0 data in the preliminary design stage, and the analysis scene is the same as 1) seat monomer mode examination, which can provide greater help for the development of the seat, better meet the needs and pursuit of users for the comfort of the seat, and thus improve the market competitiveness of the product. Through verification of multiple vehicle models: the seat same mode frequency value of the TB model under M1 data is about 0.5 Hz lower than that of the BIP result, and the precision can meet the engineering requirements.

[0034] The two-step analysis method is described in detail as follows:

[0035] 1. Seat monomer mode analysis: before this step starts, the correct seat three-dimensional design data in normal sitting, zero-gravity and other scene states needs to be provided by professional departments. The data needs to be designed, and different vehicle models have different data, and the scene states can also be designed in advance according to needs. Generally, the states of the vehicle include but are not limited to normal sitting, zero-gravity sitting, multimedia entertainment state sitting and the like. The seat three-dimensional design data of each sitting posture is different, needs to be submitted for arrangement, and after the data design is completed, the following steps are executed:

[0036] 1) import the data into the finite element pre-processing software, the software is the existing modeling software, and each time the imported data is one of the postures of the seat, for example, first import the seat three-dimensional design data in normal sitting posture, and then perform the following steps to complete the seat three-dimensional design data import and information of the next posture;

[0037] The seat three-dimensional design data is imported into the software, and then the skin, sponge, standard parts and other parts irrelevant to modal analysis are deleted according to the CAE theory, standards and specifications. According to different seat material categories, the seat material needs to be classified and defined in advance. Then the data will be automatically deleted according to the definition after importing the data, and the remaining data is the simulation required data, such as retaining the skeleton and other simulation required data.

[0038] 2) The remaining data after deletion (such as skin, sponge, standard parts and other data) needs to be separated out for creating finite element mesh. The sheet metal data is processed separately, and the sheet metal is extracted to the middle surface. The entity parts are completed according to the size and unit type requirements to complete the finite element mesh model of the seat.

[0039] 3) The stiffness information of each part of the seat is defined in advance. In this step, the parts with no stiffness or small stiffness are simulated by counterweight and assigned with corresponding parameters. The assigned parameters are pre-selected and calibrated according to vehicle information.

[0040] 4) After adjusting the parameters in the above three steps, the created finite element model is connected in the software according to the actual connection information, and the appropriate connection unit is selected to complete the connection of the finite element model of each part.

[0041] 5) There may be boundary problems in the connection process. The boundary is handled by conditional constraint, that is, the freedom degrees of the seat and the vehicle body mounting point are constrained, the modal analysis working condition is set, and the simulation model is completed based on the above parameters. Click Submit in the software to calculate according to the modeling data.

[0042] 6) The calculation results are automatically displayed, and the modal result file after solving is downloaded. Generally, these data are transferred and stored for later use and convenient verification of experimental data. The calculation results need to be imported into the simulation again and processed by the simulation software. The simulation software will identify the frequency and mode shape of each seat according to the modal output target.

[0043] 7) Compare the frequency and mode shape results of the current posture analysis with the target value. The target value is the optimal value designed in advance, which is generally an interval value. The comparison process is a simple data comparison. If the analyzed data is in the interval value, the closer to the center, the better the result. If the result is outside the target value interval, it is defined as unqualified. If it is unqualified, optimization analysis needs to be carried out according to the strain energy cloud map result of the corresponding mode, combined with cost, cycle and other factors, until the target is achieved.

[0044] 8) Finally, the seat modal result report is output, such as Figure 1The driver seat X direction mode shown in the figure is the normal sitting posture analysis. If analysis of other postures is needed, the above steps are followed to obtain the seat individual modal analysis results of each posture of the car seat.

[0045] 2. Seat installation state modal:

[0046] In normal sitting posture, zero gravity and other scenes, the BIP model analysis and TB model (soft tool version data and frozen version data) verification are needed for each working condition. According to the seat individual modeling idea, combined with the specification requirements of the BIP model, the BIP model and the TB model are completed. The following is a detailed description of the BIP model analysis and TB model (soft tool version data and frozen version data) verification:

[0047] 1) BIP model analysis

[0048] This analysis method first removes the constraints of the mounting points in the same seat individual modal analysis model, assembles it to the BIP model through the bolts, and performs free modal analysis without constraints. Then, the results (each concerned mode) are obtained by analysis, and the results (each concerned mode) are compared with the target value. Similarly, the target value is also the target value obtained by pre-selecting the design of the seat BIP model analysis of the planned analysis vehicle type. The target value is in the form of interval value as much as possible. In the comparison process, the comparison process is a simple data comparison. If the analyzed data is in the interval value, the better the result is. If the result is outside the target value interval, it is defined as unqualified. If it is unqualified, optimization analysis needs to be carried out according to the strain energy results, combined with cost, cycle, etc. This analysis step is a manual adjustment step and is not within the scope of protection of the present application. Through the adjustment of the analysis parameters each time, the target is reached, that is, the analyzed data is in the preset target value interval. For example Figure 2 The driver seat X direction mode shown in the figure:

[0049] 2) TB model verification analysis

[0050] The verification method first adds other interior and exterior data models to the same BIP model + seat single-body 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 the frozen version data are defined according to the vehicle type and configuration. If the configuration of the seat has variables, such as different soft packs, then independent verification steps need to be completed for different configurations. Then, according to the analysis results, each seat is identified for each concerned mode. The results are compared with target values. Similarly, the target values are also obtained by preselecting the design of the seat TB model verification of the vehicle type to be verified according to the plan. The target values are obtained in the form of interval values as much as possible. In the comparison process, the comparison process is a simple data comparison. If the analyzed data is in the interval value, the better the result is. If the result is outside the target value interval, it is defined as unqualified. If it is unqualified, optimization analysis needs to be carried out according to the strain energy results, combined with cost, cycle, etc. until the target is achieved. For example Figure 3 the driver's seat X-direction mode.

[0051] The above-mentioned automobile seat system modal analysis method can be applied to conventional passenger cars, such as cars, off-road vehicles, etc. The seats of the passenger cars are analyzed to obtain the optimal seat configuration scheme. The above-mentioned software method is stored in the form of program code in a storage medium. The storage medium is a computer-readable storage medium for storing software program code. The software program code is used to execute the above-mentioned automobile seat system modal analysis method. The storage medium is generally a computer storage hard disk. The functions are realized by using a computer in combination with a keyboard, a mouse, a display, a CPU, a mainboard, etc. In the realization process, other software can also be used to complete more functions.

[0052] The above describes the present application in conjunction with the drawings, and it is obvious that the specific implementation of the present application is not limited by the above method. Various non-essential improvements or direct application of the concept and technical solution of the present application to other occasions without improvement are within the protection scope of the present application.

Claims

1. A method of modal analysis of an automotive seat system, characterized by, The analysis method comprises seat single-body modal analysis, which comprises the following steps: 1) establishing three-dimensional design data of different seat modes; 2) importing three-dimensional design data of a seat mode into software; 3) deleting data irrelevant to the current seat mode; 4) data modeling to form a finite element model; 5) connecting the finite element models of various components according to actual connection information of the finite element model and selecting appropriate connection units; 6) completing boundary conditions, forming a simulation model according to the boundary conditions, and submitting the simulation model for calculation; 7) obtaining the modal results after solving, importing the results into a simulation post-processing software, identifying the frequency and vibration mode of the current seat mode according to the modal output target; 8) comparing whether the target is met to obtain a result report of the current seat mode; The data modeling is to separate the parts that need to create a finite element grid from the remaining data, extract the surface of the sheet metal, and complete the finite element grid model of the seat according to the size and unit type requirements; the data of other components with no or small stiffness is simulated by weight and given corresponding parameters; The boundary conditions: constrain the freedom degrees of the seat and the vehicle body mounting points, set the modal analysis working condition, and complete the simulation model.

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

3. The automotive seat system modal analysis method of claim 2, wherein: The data irrelevant to the current seat mode includes skin, sponge, standard parts, and the data of the seat skeleton.

4. The automotive seat system modal analysis method of claim 3, wherein: The comparison process is to compare the frequency and vibration mode of the current seat mode with the target value; if it is unqualified, optimization analysis needs to be carried out according to the strain energy cloud result of the corresponding mode, combined with the cost and cycle, until the target is achieved.

5. The automotive seat system modal analysis method according to any one of claims 1 to 4, characterized by: The analysis method further comprises seat installation state analysis: setting BIP model analysis and TB model verification under different seat mode working conditions of the seat single body, completing the BIP model and TB model according to the modeling idea of the seat single body and combining the specification requirements of the BIP model.

6. The automotive seat system modal analysis method of claim 5, wherein: The BIP model analysis is to remove the constraints of the mounting points in the same seat single-body modal analysis model, assemble it to the BIP model through bolts, and perform free modal analysis without constraints to identify each concerned mode of each seat, compare the results with the target value, and if it is unqualified, optimization analysis needs to be carried out according to the strain energy result, combined with the cost and cycle, until the target is achieved.

7. The automotive seat system modal analysis method of claim 6, wherein: The TB model verification: combining the same BIP model with the seat single-body modal analysis model, adding the data model of the interior and exterior trim to achieve the TB model, performing free modal analysis without constraints to identify each concerned mode of each seat, comparing the results with the target value, and if it is unqualified, optimization analysis needs to be carried out according to the strain energy result, combined with the cost and cycle, until the target is achieved.

8. A storage medium, the storage medium being a computer-readable storage medium for storing a software program code, characterized in that: The software program code is used to execute the modal analysis method of the automobile seat system according to any one of claims 1-7.

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