Vehicle ride comfort simulation analysis method, device, equipment, medium and program product

Abstract

The invention discloses a vehicle ride comfort simulation analysis method, device and equipment, a medium and a program product, and relates to the technical field of vehicle dynamics simulation. The method comprises the steps that vibration transfer functions from a seat guide rail mounting point of a vehicle to the position above a seat cushion and from a seat backrest are obtained, and vibration acceleration response of a cab floor and vibration acceleration response of the seat guide rail mounting point are obtained; based on the vibration transfer function and the vibration acceleration response of the seat guide rail mounting point, the vibration acceleration response of the upper portion of the seat cushion and the vibration acceleration response of the seat backrest are determined; and determining the smoothness performance of the vehicle based on the vibration acceleration response above the seat cushion and the seat back and the vibration acceleration response of the cab floor. According to the method and the device, the vibration acceleration response above the seat cushion and the seat backrest can be accurately obtained based on the vibration transfer function and the vibration acceleration response of the seat guide rail mounting point, a real physical phenomenon can be reflected, and the accuracy of vehicle ride comfort evaluation is improved.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle dynamics simulation, and in particular to a vehicle ride comfort simulation analysis method, device, equipment, medium and program product. Background Art

[0002] Vehicle smoothness is an important indicator for evaluating the comfort performance of the entire vehicle, and it represents the subjective feeling of the passengers caused by the vibration inside the vehicle caused by road excitation during driving.

[0003] In the related art, the simulation analysis of vehicle ride comfort is usually performed based on the simulation model. However, the human body and the seat are usually simplified in the simulation model, for example, the mass of the seat foam material and the mass of the person are replaced by the concentrated mass, and the influence of the damping and stiffness of the structural tissues such as the human joints and muscles on the vibration of the seat-human body system is not considered, and the coupling effect between the seat and the occupant is ignored, so that the real physical phenomenon cannot be reflected, resulting in poor accuracy in the evaluation of vehicle ride comfort. Summary of the invention

[0004] In view of this, embodiments of the present application provide a vehicle ride comfort simulation analysis method, device, equipment, medium and program product.

[0005] The technical solution of the embodiment of the present application is implemented as follows:

[0006] In a first aspect, an embodiment of the present application provides a vehicle smoothness simulation analysis method, including: obtaining vibration transfer functions from the vehicle's seat rail mounting points to the top of the seat cushion and the seat back, as well as the vibration acceleration response of the vehicle's cab floor and the vibration acceleration response of the seat rail mounting points; determining the vibration acceleration response above the seat cushion and the vibration acceleration response of the seat back based on the vibration transfer functions from the seat rail mounting points to the top of the seat cushion and the seat back, as well as the vibration acceleration response of the seat rail mounting points; determining the smoothness performance of the vehicle based on the vibration acceleration response above the seat cushion, the vibration acceleration response of the seat back and the vibration acceleration response of the cab floor.

[0007] By adopting the technical solution of the present application, firstly, the vibration transfer functions from the seat rail mounting point of the vehicle to the upper part of the seat cushion and the seat back, as well as the vibration acceleration response of the vehicle's cab floor and the vibration acceleration response of the seat rail mounting point are obtained; secondly, based on the vibration transfer functions from the seat rail mounting point to the upper part of the seat cushion and the seat back, as well as the vibration acceleration response of the seat rail mounting point, the vibration acceleration response of the upper part of the seat cushion and the vibration acceleration response of the seat back are determined, whereby the complex modeling of the seat and occupant model is innovatively skipped, and based on the vibration transfer functions from the seat rail mounting point to the upper part of the seat cushion and the seat back, as well as the vibration acceleration response of the seat rail mounting point, the vibration acceleration response of the upper part of the seat cushion and the vibration acceleration response of the seat back can be accurately obtained, which can reflect the real physical phenomenon; finally, based on the vibration acceleration response of the upper part of the seat cushion, the vibration acceleration response of the seat back and the vibration acceleration response of the cab floor, the smoothness performance of the vehicle is determined, thereby improving the accuracy of the vehicle smoothness evaluation.

[0008] In some embodiments, the vibration transfer function is obtained based on experimental testing of a target vehicle finite element model with occupants of different weights, and the vibration acceleration response of the cab floor and the vibration acceleration response of the seat rail mounting point are obtained based on simulation of the target vehicle finite element model.

[0009] According to the above technical means, by conducting tests based on the finite element model of the target vehicle with occupants of different weights, the vibration transfer functions from the seat rail installation point to the top of the seat cushion and the seat back are obtained, which can better correspond the simulation conditions with the actual vehicle test conditions and improve the simulation accuracy. In addition, by simulating the finite element model of the target vehicle to obtain the vibration acceleration response of the cab floor and the vibration acceleration response of the seat rail installation point, the accuracy of the vibration acceleration response simulation can be improved.

[0010] In some embodiments, the vehicle smoothness simulation analysis method also includes: constructing an initial whole vehicle finite element model; based on the initial whole vehicle finite element model, obtaining the Hop modal simulation frequency of the vehicle's suspension in the vertical direction and the Bounce modal simulation frequency of the vehicle's powertrain in the vertical direction; obtaining the Hop modal theoretical calculation frequency of the vehicle's suspension in the vertical direction and the Bounce modal theoretical calculation frequency of the vehicle's powertrain in the vertical direction; based on the Hop modal simulation frequency, the Bounce modal simulation frequency, the Hop modal theoretical calculation frequency and the Bounce modal theoretical calculation frequency, calibrating the initial whole vehicle finite element model to obtain a target whole vehicle finite element model.

[0011] According to the above technical means, first, an initial whole vehicle finite element model is constructed; secondly, based on the initial whole vehicle finite element model, the Hop modal simulation frequency of the vehicle's suspension in the vertical direction and the Bounce modal simulation frequency of the vehicle's powertrain in the vertical direction are obtained; then, the Hop modal theoretical calculation frequency of the vehicle's suspension in the vertical direction and the Bounce modal theoretical calculation frequency of the vehicle's powertrain in the vertical direction are obtained; finally, based on the Hop modal simulation frequency, the Bounce modal simulation frequency, the Hop modal theoretical calculation frequency and the Bounce modal theoretical calculation frequency, the initial whole vehicle finite element model is calibrated to obtain the target whole vehicle finite element model, so that the accuracy and reliability of the simulation of the target whole vehicle finite element model can be improved, providing a solid foundation for vehicle smoothness simulation analysis.

[0012] In some embodiments, the vehicle ride comfort simulation analysis method further includes: when constructing an initial whole vehicle finite element model, using a concentrated mass model to perform equivalent processing on the occupants.

[0013] According to the above technical means, by using the concentrated mass model to perform equivalent treatment on the occupants when constructing the initial whole vehicle finite element model, the concentrated mass model can more accurately simulate the dynamic response of the occupants in the vehicle through reasonable mass distribution and setting of spring damping parameters, and reflect the interaction between the occupants and the vehicle seats.

[0014] In some embodiments, after the initial whole vehicle finite element model is calibrated based on the Hop modal simulation frequency, the Bounce modal simulation frequency, the Hop modal theoretical calculation frequency and the Bounce modal theoretical calculation frequency to obtain the target whole vehicle finite element model, the vehicle smoothness simulation analysis method also includes: obtaining a super unit model of the chassis and body of the vehicle; using the super unit model of the chassis and body to simplify the calibrated target whole vehicle finite element model to obtain a simplified target whole vehicle finite element model.

[0015] According to the above technical means, the calibrated target vehicle finite element model is simplified by using the super-element model of the chassis and the body to obtain a simplified target vehicle finite element model. In this way, the super-element model significantly reduces the number of computational nodes and degrees of freedom in the target vehicle finite element model by simplifying the complex structure of the chassis and the body into a limited number of super-elements. This enables the target vehicle finite element model to complete simulation and analysis faster under the same computing resources, thereby improving computing efficiency.

[0016] In some embodiments, before obtaining the Hop modal simulation frequency of the vehicle's suspension in the vertical direction and the Bounce modal simulation frequency of the vehicle's powertrain in the vertical direction based on the initial whole vehicle finite element model, the vehicle smoothness simulation analysis method also includes: obtaining target parameters of the initial whole vehicle finite element model; based on the target parameters, optimizing the initial whole vehicle finite element model; wherein the target parameters include at least one of the following: mass and center of mass of the powertrain, dynamic stiffness and damping of the powertrain suspension system, damping of the suspension shock absorber, stiffness of the suspension spring, dynamic stiffness and damping of the suspension bushing.

[0017] According to the above technical means, first, at least one target parameter of the mass and center of mass of the powertrain, the dynamic stiffness and damping of the powertrain suspension system, the damping of the suspension shock absorber, the stiffness of the suspension spring, and the dynamic stiffness and damping of the suspension bushing of the initial whole vehicle finite element model is obtained; then, based on the obtained target parameters, the initial whole vehicle finite element model is optimized to improve the accuracy and reliability of the initial whole vehicle finite element model.

[0018] In some embodiments, the vibration acceleration response of the vehicle's cab floor and the vibration acceleration response of the seat rail mounting point are obtained, including: obtaining a road surface power spectrum density for reflecting road surface unevenness; and simulating and obtaining the vibration acceleration response of the cab floor and the vibration acceleration response of the seat rail mounting point based on the road surface power spectrum density and a target vehicle finite element model.

[0019] According to the above technical means, firstly, the road surface power spectrum density used to reflect the road surface roughness is obtained; secondly, based on the road surface power spectrum density and the target vehicle finite element model, the vibration acceleration response of the cab floor and the vibration acceleration response of the seat rail installation point are simulated. Since the road surface power spectrum density is a statistical characteristic that describes the road surface roughness, it can accurately reflect the excitation conditions of the actual road surface. By taking the road surface power spectrum density as input, the target vehicle finite element model can more accurately simulate the dynamic response of the vehicle on the real road surface, and accurately simulate the vibration acceleration response of the cab floor and the vibration acceleration response of the seat rail installation point.

[0020] In some embodiments, obtaining a road surface power spectrum density for reflecting road surface roughness includes: obtaining road surface roughness test data; performing Fourier transform on the road surface roughness test data to obtain a road surface spatial frequency spectrum; and obtaining a road surface power spectrum density based on the road surface spatial frequency spectrum.

[0021] According to the above technical means, first, the road surface roughness test data is obtained; secondly, the road surface roughness test data is Fourier transformed to obtain the road surface spatial frequency spectrum; then, based on the road surface spatial frequency spectrum, the road surface power spectrum density is obtained. In this way, by obtaining the road surface roughness test data and performing Fourier transform and power spectrum density analysis, the road surface roughness characteristics can be accurately described, providing a solid foundation for the target vehicle finite element model to accurately simulate the dynamic response of the vehicle on the road.

[0022] In a second aspect, an embodiment of the present application provides a vehicle ride comfort simulation analysis device, comprising:

[0023] An acquisition module, used to obtain vibration transfer functions from a seat rail installation point of a vehicle to an upper portion of a seat cushion and a seat back, respectively, and a vibration acceleration response of a cab floor of the vehicle and a vibration acceleration response of the seat rail installation point;

[0024] a first determination module, configured to determine a vibration acceleration response above the seat cushion and a vibration acceleration response of the seat back based on vibration transfer functions from the seat rail mounting point to the upper portion of the seat cushion and the seat back, respectively, and a vibration acceleration response of the seat rail mounting point;

[0025] The second determination module is used to determine the ride comfort of the vehicle based on the vibration acceleration response above the seat cushion, the vibration acceleration response of the seat back, and the vibration acceleration response of the cab floor.

[0026] In a third aspect, an embodiment of the present application provides an electronic device, comprising a memory and a processor, wherein the memory is used to store executable data instructions; when the processor is used to execute the executable data instructions stored in the memory, the vehicle smoothness simulation analysis method as described in the first aspect is implemented.

[0027] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, the vehicle smoothness simulation analysis method as described in the first aspect is implemented.

[0028] In a fifth aspect, an embodiment of the present application provides a computer program product, including a computer program or instructions, which, when executed by a processor, implements the vehicle smoothness simulation analysis method as described in the first aspect.

[0029] Beneficial effects of this application:

[0030] By adopting the technical solution of the present application, it is possible to innovatively skip the complex modeling of the seat and occupant model. By using the vibration transfer function from the seat rail mounting point to the top of the seat cushion and the seat back, as well as the vibration acceleration response of the seat rail mounting point, it is possible to accurately obtain the vibration acceleration response of the top of the seat cushion and the vibration acceleration response of the seat back, which can reflect the real physical phenomena and improve the accuracy of the vehicle smoothness evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief introduction will be given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 One of the flow charts of a vehicle ride comfort simulation analysis method provided in an embodiment of the present application;

[0033] Figure 2 A second flow chart of a vehicle ride comfort simulation analysis method provided in an embodiment of the present application;

[0034] Figure 3 A third flow chart of a vehicle ride comfort simulation analysis method provided in an embodiment of the present application;

[0035] Figure 4 A schematic diagram of a road surface random excitation test provided in an embodiment of the present application;

[0036] Figure 5 One of the schematic diagrams of the results of a road random excitation test provided in an embodiment of the present application;

[0037] Figure 6 A second schematic diagram of the results of a road random excitation test provided in an embodiment of the present application;

[0038] Figure 7 A third schematic diagram of the results of a road random excitation test provided in an embodiment of the present application;

[0039] Figure 8 A schematic diagram of a vibration transfer function test structure provided in an embodiment of the present application;

[0040] Fig. 9 A schematic diagram showing the comparison between the simulation and experimental test results of the vibration acceleration response of the left rear mounting point of a seat rail provided in an embodiment of the present application;

[0041] Fig.10A schematic diagram of a comprehensive evaluation of the ride comfort performance of a vehicle based on the vibration acceleration response of the cab floor, the top of the seat cushion and the seat back provided in an embodiment of the present application;

[0042] Fig.11 A schematic diagram of the structure of a vehicle ride comfort simulation analysis system provided in an embodiment of the present application;

[0043] Fig.12 A schematic diagram of the structure of a vehicle ride comfort simulation and analysis device provided in an embodiment of the present application;

[0044] Fig.13 A schematic diagram of the physical structure of an electronic device provided in an embodiment of the present application.

[0045] Reference numerals:

[0046] 1: Clamping equipment; 2: Clamping equipment; 3: Test vehicle; L1: Laser probe; L2: Laser probe; L3: Laser probe; L4: Laser probe. DETAILED DESCRIPTION

[0047] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0048] It should be noted that in the description of the embodiments of the present application, the terms "first", "second", etc. are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more.

[0049] In order to facilitate a clearer understanding of the embodiments of the present application, some related technologies are first introduced as follows.

[0050] The national standard on the test method of automobile ride comfort clearly stipulates the evaluation method of automobile ride comfort: when carrying passengers, the total weighted acceleration root mean square value of each point above the seat cushion, seat back and cab floor is used as the evaluation index for evaluation. Therefore, in order for the simulation results of automobile ride comfort to correspond to the test results, it is necessary to extract the vibration acceleration response of different response points and weight them as the simulation index for ride comfort evaluation in the simulation analysis. In addition, the national standard stipulates that during the ride comfort test, the occupants on the seats should relax their whole body, wear seat belts, and put their hands naturally on their thighs. The driver's hands are naturally on the steering wheel, and the sitting posture should remain unchanged during the test. Therefore, in order to obtain the simulation results corresponding to the test conditions, the sitting posture of the occupants or drivers needs to be correctly simulated in the simulation model.

[0051] However, in the current simulation model, the modeling of the human body model and the seat model with foam material faces great challenges. At present, the seat and human body model are usually greatly simplified in the simulation model, such as using concentrated mass to replace the mass of the seat foam material and the mass of the person. Even if there are simulation analysis methods for establishing seat and dummy models, they do not consider the influence of the damping and stiffness of structural tissues such as human joints and muscles on the vibration of the seat-human body system, and cannot obtain the real objective vibration performance of the human body. The analysis method has limitations. In addition, due to the coupling effect between the human body and the seat, when the occupant sits on the seat, the first-order mode of the seat will be improved to a certain extent due to the change of the seat boundary, and the existing analysis method does not take this phenomenon into account.

[0052] In the related art, a vehicle smoothness simulation analysis method based on a dummy-seat dynamic model is proposed. This method calibrates the dummy-seat dynamic model based on the test results of the stiffness and damping of the test seat, and obtains the vehicle smoothness results based on random road excitation and pulse excitation simulation. The time domain simulation accuracy can reach 90%, which solves the problem of large errors in vehicle smoothness simulation results and has high applicability. Although this method takes into account the influence of occupants or drivers on the results, it still simplifies the dummy model into a concentrated mass, which is inconsistent with the seat-occupant state specified in the national standard. At the same time, it does not consider the influence of occupant-seat coupling on the mode, and cannot reflect the real physical phenomenon. The accuracy of vehicle smoothness evaluation is not high.

[0053] In order to overcome at least some of the above-mentioned defects existing in the related art, the embodiments of the present application provide a vehicle smoothness simulation analysis method, device, equipment, medium and program product, which can innovatively skip the complex modeling of seat and occupant models, and can accurately obtain the vibration acceleration response of the seat cushion and the seat back based on the vibration transfer function from the seat rail mounting point to the top of the seat cushion and the seat back, as well as the vibration acceleration response of the seat rail mounting point, so as to reflect the real physical phenomenon and improve the accuracy of the vehicle smoothness evaluation.

[0054] The following is an illustrative introduction to the vehicle ride comfort simulation analysis method, device, equipment, medium and program product provided in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application.

[0055] Figure 1 One of the flow charts of a vehicle ride comfort simulation analysis method provided in an embodiment of the present application is as follows: Figure 1 As shown, the method includes:

[0056] S101. Obtain vibration transfer functions from a seat rail installation point of a vehicle to an upper portion of a seat cushion and a seat back, respectively, as well as a vibration acceleration response of a cab floor of the vehicle and a vibration acceleration response of the seat rail installation point.

[0057] It should be noted that the vibration transfer function from the seat rail mounting point to the top of the seat cushion can reflect the vibration transfer from the seat rail mounting point to the top of the seat cushion, and the vibration transfer function from the seat rail mounting point to the seat back can reflect the vibration transfer from the seat rail mounting point to the seat back. In other words, the vibration transfer function can reflect the isolation and attenuation capabilities of the seat system for vibration from the floor (or body).

[0058] It should be noted that the vibration acceleration response of the cab floor can reflect the stability of the vehicle's driving. If the vibration acceleration is too large, it means that the vehicle may have encountered an uneven road surface or a problem with the suspension system during driving, resulting in a large vibration of the cab floor.

[0059] It should be noted that the vibration acceleration response of the seat rail installation point can reflect the vibration isolation performance of the seat system. As an important component connecting the cab floor and the occupants, the vibration isolation performance of the seat system directly affects the vibration intensity felt by the occupants.

[0060] In some embodiments, the vibration transfer functions from the seat rail mounting point to the seat cushion and the seat back, as well as the vibration acceleration response of the cab floor and the vibration acceleration response of the seat rail mounting point can be obtained based on a simulation method.

[0061] In some embodiments, the vibration transfer functions from the seat rail mounting point to the top of the seat cushion and the seat back, as well as the vibration acceleration response of the cab floor and the vibration acceleration response of the seat rail mounting point can be obtained based on a simulation combined with experimental testing.

[0062] S102: Determine the vibration acceleration response above the seat cushion and the vibration acceleration response of the seat back based on the vibration transfer functions from the seat rail mounting point to the upper part of the seat cushion and the seat back, and the vibration acceleration response of the seat rail mounting point.

[0063] In an embodiment of the present application, the vibration acceleration response above the seat cushion can be determined based on the mathematical relationship among the vibration transfer function from the seat rail mounting point to the top of the seat cushion, the vibration acceleration response of the seat rail mounting point, and the vibration acceleration response above the seat cushion; similarly, the vibration acceleration response of the seat back can be determined based on the mathematical relationship among the vibration transfer function from the seat rail mounting point to the seat back, the vibration acceleration response of the seat rail mounting point, and the vibration acceleration response of the seat back.

[0064] S103: Determine the ride comfort of the vehicle based on the vibration acceleration response above the seat cushion, the vibration acceleration response of the seat back, and the vibration acceleration response of the cab floor.

[0065] In the embodiment of the present application, the weighted effective value calculation can be performed on the vibration acceleration response above the seat cushion, the vibration acceleration response of the seat back and the vibration acceleration response of the cab floor, and then the total weighted effective value of the acceleration above the seat cushion, the seat back and the cab floor is calculated, and then the calculated weighted effective value and the total weighted effective value of the acceleration are compared with relevant evaluation standards to determine the smooth performance of the vehicle. These standards may be related to the physiological response of the human body to vibration and the requirements for ride comfort.

[0066] It can be understood that the vehicle smoothness simulation and analysis method provided in the embodiment of the present application can innovatively skip the complex modeling of the seat and occupant model, and can accurately obtain the vibration acceleration response above the seat cushion and the vibration acceleration response of the seat back based on the vibration transfer function from the seat rail mounting point to the top of the seat cushion and the seat back, as well as the vibration acceleration response of the seat rail mounting point, thereby reflecting the real physical phenomenon and improving the accuracy of the vehicle smoothness evaluation.

[0067] In some embodiments, the vibration transfer function is obtained based on experimental testing of a target vehicle finite element model corresponding to the vehicle with occupants of different weights, and the vibration acceleration response of the cab floor and the vibration acceleration response of the seat rail mounting point are obtained based on simulation of the target vehicle finite element model.

[0068] In the embodiment of the present application, the vibration transfer function from the seat rail mounting point to the top of the seat cushion and the seat back can be tested by experimental methods using the target vehicle finite element model. At the same time, in order to examine the influence of the occupant's weight on the smoothness result, during the transfer function test, occupants of different weights can be set in the target vehicle finite element model, and then the vibration transfer function under various conditions can be tested to better match the simulation working conditions with the working conditions of the actual vehicle test and improve the simulation accuracy. Moreover, in the embodiment of the present application, the vibration acceleration response of the cab floor and the vibration acceleration response of the seat rail mounting point can also be obtained based on the simulation of the target vehicle finite element model.

[0069] It should be noted that the target vehicle finite element model contains a large number of units and nodes to simulate the overall structure and performance of the vehicle. These units and nodes are interconnected through complex connection relationships to form a complete system. The target vehicle finite element model can accurately reflect the actual structure and material properties of the vehicle, including the geometry, material properties and connection relationships of various components such as the body, chassis and powertrain. Through reasonable meshing and boundary condition settings, the target vehicle finite element model can achieve accurate simulation and analysis of vehicle performance. In addition, the target vehicle finite element model can involve the coupling analysis of multiple physical fields, such as structural mechanics, thermodynamics and fluid mechanics. The interaction and influence between these physical fields make the analysis of the target vehicle finite element model more complex and comprehensive. Through multi-physical field coupling analysis, the performance and response of the vehicle under different working conditions can be more accurately evaluated.

[0070] In some embodiments, corresponding excitations, such as road roughness excitations, can be applied to the target vehicle finite element model, and then the set target vehicle finite element model is submitted to the solver for calculation, and the vibration acceleration responses of the cab floor and seat rail mounting points are extracted from the simulation results.

[0071] It should be noted that the vibration transfer function can be tested multiple times based on different weights of the occupants to obtain a more accurate vibration transfer function. The occupant weight can be set according to the adaptability of the actual application, and the embodiment of the present application does not specifically limit this.

[0072] It can be understood that the embodiment of the present application obtains the vibration transfer function from the seat rail installation point to the top of the seat cushion and the seat back respectively by conducting tests based on the target vehicle finite element model with occupants of different weights, which can better correspond the simulation conditions with the actual vehicle test conditions and improve the simulation accuracy. In addition, by simulating the target vehicle finite element model to obtain the vibration acceleration response of the cab floor and the vibration acceleration response of the seat rail installation point, the accuracy of the vibration acceleration response simulation can be improved.

[0073] In some embodiments, the vehicle ride comfort simulation analysis method further includes:

[0074] Construct an initial vehicle finite element model;

[0075] Based on the initial vehicle finite element model, obtaining a Hop modal simulation frequency of the suspension of the vehicle in a vertical direction and a Bounce modal simulation frequency of the powertrain of the vehicle in a vertical direction;

[0076] Obtaining a Hop modal theoretically calculated frequency of the suspension of the vehicle in the vertical direction and a Bounce modal theoretically calculated frequency of the powertrain of the vehicle in the vertical direction;

[0077] Based on the Hop modal simulation frequency, the Bounce modal simulation frequency, the Hop modal theoretical calculation frequency and the Bounce modal theoretical calculation frequency, the initial whole vehicle finite element model is calibrated to obtain the target whole vehicle finite element model.

[0078] It should be noted that the Hop modal frequency of the vehicle's suspension in the vertical direction and the Bounce modal frequency of the vehicle's powertrain in the vertical direction affect the vehicle's driving stability and the comfort of the passengers. Among them, the Bounce modal frequency refers to the vibration frequency of the powertrain in the vertical direction due to inertia and road excitation.

[0079] It should be noted that the vertical direction may be a direction perpendicular to the entire vehicle or the road surface.

[0080] In an embodiment of the present application, an initial whole-vehicle finite element model can be first constructed, and then simulation can be performed based on the initial whole-vehicle finite element model to obtain the Hop modal simulation frequency of the vehicle's suspension in the vertical direction and the Bounce modal simulation frequency of the vehicle's powertrain in the vertical direction. The Hop modal simulation frequency and the Bounce modal simulation frequency can then be compared with the Hop modal theoretical calculation frequency and the Bounce modal theoretical calculation frequency, respectively. Based on the comparison results, the initial whole-vehicle finite element model can be calibrated to obtain the calibrated target whole-vehicle finite element model.

[0081] In some embodiments, professional finite element analysis software may be used to perform theoretical analysis and calculation on the theoretical calculation frequency of the Hop modal of the suspension in the vertical direction and the theoretical calculation frequency of the Bounce modal of the powertrain in the vertical direction.

[0082] In some embodiments, a preliminary three-dimensional model can be first created using three-dimensional modeling software according to the geometric dimensions of the vehicle, including key components such as the body, chassis, powertrain and seats; then, according to the geometric shape and material properties of the vehicle, appropriate unit types are selected, such as shell units, solid units and beam units (ensuring that the unit type can accurately reflect the mechanical properties of the structure), and the three-dimensional model is meshed using finite element analysis software to generate nodes and units; secondly, according to the material properties of the vehicle, key parameters such as Young's modulus, density, Poisson's ratio, etc. are defined, and the defined material properties are assigned to the corresponding units or components; then, according to the analysis requirements, reasonable boundary conditions are set, such as fixed constraints, displacement constraints, etc., to ensure that the boundary conditions can accurately reflect the actual working state of the vehicle, and at the same time, according to the load conditions of the vehicle, corresponding loads are applied, such as gravity, inertia force and external excitation, to ensure that the size, direction and position of the load are accurate; finally, according to the connection method of the vehicle (such as bolt connection, spot welding, gluing, etc.), a suitable unit type or connection method is selected for simulation to ensure the accuracy and reliability of the connection method, thereby obtaining an initial whole vehicle finite element model.

[0083] In some embodiments, the Hop modal simulation frequency and the Bounce modal simulation frequency can be compared with the Hop modal theoretical calculation frequency and the Bounce modal theoretical calculation frequency respectively, and the error can be controlled within 0.5 Hz to achieve the calibration of the initial vehicle finite element model and obtain the calibrated target vehicle finite element model.

[0084] It can be understood that the embodiment of the present application calibrates the initial vehicle finite element model based on the Hop modal frequency of the suspension in the vertical direction and the Bounce modal frequency of the powertrain in the vertical direction to obtain the calibrated target vehicle finite element model, which can improve the accuracy and reliability of the simulation of the target vehicle finite element model and provide a solid foundation for vehicle smoothness simulation analysis.

[0085] In some embodiments, the vehicle ride comfort simulation analysis method further includes:

[0086] When constructing the initial vehicle finite element model, the occupants are treated equivalently using a concentrated mass model.

[0087] In the embodiment of the present application, when constructing the initial vehicle finite element model, one or more mass points can be created in the finite element analysis software, whose mass is equal to the mass of the occupant, and then the mass points are connected to the appropriate positions of the vehicle structure using appropriate connection units (such as rigid connections, spring-damper units, etc.). These connection units can simulate the interaction between the occupant and the vehicle structure, thereby achieving equivalent treatment of the occupant using a concentrated mass model.

[0088] It can be understood that the embodiment of the present application performs equivalent treatment of the occupants by utilizing a concentrated mass model. The concentrated mass model can more accurately simulate the dynamic response of the occupants in the vehicle and reflect the interaction between the occupants and the vehicle seats through reasonable mass distribution and setting of spring and damping parameters.

[0089] In some embodiments, after calibrating the initial vehicle finite element model based on the Hop modal simulation frequency, the Bounce modal simulation frequency, the Hop modal theoretical calculation frequency, and the Bounce modal theoretical calculation frequency to obtain the target vehicle finite element model, the method further includes:

[0090] Obtaining a super unit model of the chassis and body of the vehicle;

[0091] The calibrated target vehicle finite element model is simplified using the super unit models of the chassis and the vehicle body to obtain a simplified target vehicle finite element model.

[0092] It should be noted that the super-element model (also called the substructure model) divides a large structure into smaller, relatively independent substructures, analyzes these substructures separately, and then combines them to simulate the dynamic behavior of the entire structure.

[0093] In some embodiments, the vehicle chassis can be divided into multiple substructures, such as front suspension, rear suspension, transmission system and subframe, etc. according to its geometric shape, functional components and connection points, and the body can be divided into multiple areas or modules, such as doors, roof and engine compartment, etc., and then each substructure or module is modeled in detail, including meshing, material property definition and connection unit setting, etc., and then each substructure is subjected to modal analysis or static analysis using finite element analysis software to extract its internal degrees of freedom (internal nodes) and external degrees of freedom (nodes connected to other substructures). Based on the analysis results, a super unit model is created, which only retains the external degrees of freedom, and the influence of the internal degrees of freedom is integrated into the external degrees of freedom through reduction techniques (such as static reduction or dynamic reduction). Finally, the super unit models of the chassis and body are assembled together according to the actual connection method and position to obtain a simplified finite element model of the target vehicle.

[0094] It can be understood that the embodiment of the present application simplifies the calibrated target vehicle finite element model by utilizing the super unit models of the chassis and the body, which can significantly reduce the number of computational nodes and degrees of freedom in the target vehicle finite element model. This enables the target vehicle finite element model to complete simulation and analysis faster with the same computing resources, thereby improving computing efficiency.

[0095] In some embodiments, before obtaining the Hop modal simulation frequency of the suspension of the vehicle in the vertical direction and the Bounce modal simulation frequency of the powertrain of the vehicle in the vertical direction based on the initial vehicle finite element model, the method further includes:

[0096] Obtaining target parameters of the initial vehicle finite element model;

[0097] Based on the target parameters, optimizing the initial vehicle finite element model;

[0098] The target parameter includes at least one of the following:

[0099] The mass and center of mass of the powertrain, the dynamic stiffness and damping of the powertrain suspension system, the damping of the suspension shock absorber, the stiffness of the suspension spring, the dynamic stiffness and damping of the suspension bushing.

[0100] It should be noted that the mass and center of mass of the powertrain, the dynamic stiffness and damping of the powertrain suspension system, the damping of the suspension shock absorber, the stiffness of the suspension spring, and the dynamic stiffness and damping of the suspension bushing have a significant impact on the vehicle smoothness evaluation.

[0101] In an embodiment of the present application, at least one target parameter of the mass and center of mass of the powertrain, the dynamic stiffness and damping of the powertrain suspension system, the damping of the suspension shock absorber, the stiffness of the suspension spring, and the dynamic stiffness and damping of the suspension bushing of the initial vehicle finite element model can be obtained based on the experimental testing method, and then based on the obtained target parameters, the initial vehicle finite element model is optimized, so that the initial vehicle finite element model is significantly improved in simulation accuracy and reliability.

[0102] In some embodiments, obtaining the vibration acceleration response of the vehicle's cab floor and the vibration acceleration response of the seat rail mounting point includes:

[0103] Obtaining a road surface power spectrum density for reflecting road surface roughness;

[0104] Based on the road surface power spectrum density and the target vehicle finite element model, the vibration acceleration response of the cab floor and the vibration acceleration response of the seat rail mounting point are obtained by simulation.

[0105] In an embodiment of the present application, in order to obtain the vibration acceleration response of the vehicle's cab floor and the vibration acceleration response of the seat rail installation point, the road surface power spectral density (PSD) used to reflect the unevenness of the road surface can be first obtained, and then based on the road surface power spectral density and the target vehicle finite element model, the vibration acceleration response of the cab floor and the vibration acceleration response of the seat rail installation point can be simulated to obtain.

[0106] It should be noted that the pavement power spectral density is a statistical characteristic that describes the roughness of the pavement and can accurately reflect the excitation conditions of the actual pavement.

[0107] For example, Figure 2 A second flow chart of a vehicle ride comfort simulation analysis method provided in an embodiment of the present application is shown in FIG. Figure 2 As shown, the method includes:

[0108] S201: Obtain a road surface power spectrum density for reflecting road surface roughness.

[0109] S202. Based on the road surface power spectrum density and the target vehicle finite element model, the vibration acceleration response of the cab floor and the vibration acceleration response of the seat rail mounting point are obtained by simulation, and based on the target vehicle finite element model, simulation tests are performed on the state of occupants of different weights sitting on the seats to obtain the vibration transfer functions from the seat rail mounting point to the top of the seat cushion and the seat back, respectively.

[0110] S203: Determine the vibration acceleration response above the seat cushion and the vibration acceleration response of the seat back based on the vibration transfer functions from the seat rail mounting point to the upper part of the seat cushion and the seat back, and the vibration acceleration response of the seat rail mounting point.

[0111] S204: Determine the ride comfort of the vehicle based on the vibration acceleration response above the seat cushion, the vibration acceleration response of the seat back, and the vibration acceleration response of the cab floor.

[0112] It should be noted that, for the description of the same steps and the same contents in this embodiment as those in other embodiments, reference can be made to the description in other embodiments and will not be repeated here.

[0113] It can be understood that the embodiment of the present application uses the road power spectrum density as input, so that the target vehicle finite element model can more accurately simulate the dynamic response of the vehicle on the real road surface, and accurately simulate the vibration acceleration response of the cab floor and the vibration acceleration response of the seat rail installation point.

[0114] In some embodiments, obtaining a road surface power spectrum density for reflecting road surface roughness includes:

[0115] Obtain road roughness test data;

[0116] Performing Fourier transformation on the road surface roughness test data to obtain a road surface spatial frequency spectrum;

[0117] The road surface power spectrum density is obtained based on the road surface spatial frequency spectrum.

[0118] In an embodiment of the present application, a road surface roughness test can be performed on the test road surface to obtain road surface roughness test data, and then the road surface roughness test data can be Fourier transformed using a fast Fourier transform algorithm to obtain a road surface spatial frequency spectrum, and then based on the mathematical relationship between the road surface spatial frequency spectrum and the road surface power spectrum density, the road surface spatial frequency spectrum can be converted into a road surface power spectrum density.

[0119] It should be noted that the road surface spatial frequency spectrum describes the frequency characteristics of road surface roughness as it changes with spatial position. It indicates the distribution of roughness of different wavelengths (or spatial frequencies) in the length direction of the road surface. The road surface power spectrum density is a statistic that describes the distribution of road surface roughness energy with frequency. It indicates the energy or power contained in the road surface roughness within a unit frequency range.

[0120] It can be understood that the embodiments of the present application can accurately describe the road surface roughness characteristics by obtaining road surface roughness test data and performing Fourier transform and power spectral density analysis, thereby providing a solid foundation for the target vehicle finite element model to accurately simulate the dynamic response of the vehicle on the road surface.

[0121] The following is an explanation of an exemplary application of an embodiment of the present application in a practical application scenario.

[0122] It should be noted that the embodiment of the present application will use the vehicle smoothness analysis of a certain vehicle model on a rough asphalt road as an example to illustrate the implementation method. The analysis methods for other vehicle models or other road surfaces are similar and can be referred to the implementation methods of the embodiment of the present application.

[0123] Figure 3 A third flow chart of a vehicle ride comfort simulation analysis method provided in an embodiment of the present application is shown in FIG. Figure 3 As shown, the method includes:

[0124] S301, road surface excitation test and conversion.

[0125] In the embodiment of the present application, a road random excitation test can be performed, and the road random excitation test data can be converted into a road power spectrum density used for analysis as an excitation source for simulation. In the embodiment of the present application, an excitation test of a rough asphalt road surface is used as an example for explanation.

[0126] It should be noted that the smoothness problem caused by the road surface is caused by the vibration inside the car caused by random excitation of the road surface, and it is necessary to use the random excitation method for analysis. For the multi-input and multi-output system of the whole vehicle, it is necessary to obtain the vibration response of a certain point inside the car.

[0127] In some embodiments, the vibration response of a certain point in the vehicle can be calculated using the following formula (1):

[0128]

[0129] Among them, TF 1-4 are the vibration transfer functions from the vehicle's left front wheel, right front wheel, left rear wheel, and right rear wheel excitation points to the required response points; P 11 , P 22 , P 33 , P 44 are the autospectral densities of the road excitations on the left front wheel, right front wheel, left rear wheel, and right rear wheel of the vehicle, respectively, P ij (i,j=1,2,3,4 and i≠j) is the cross-spectral density of the road excitation received by each wheel. The autospectral density and cross-spectral density of the excitation are obtained through experimental tests. Therefore, from formula (1), it can be seen that to obtain the vibration response of a certain response point in the vehicle, the key is to determine the vibration transfer function from the tire excitation point to a certain response point in the vehicle and the power spectral density of the excitation. PSD_R represents the power spectral density matrix of the excitation.

[0130] It should be noted that when a vehicle is traveling on a road, the excitation of the road surface on the tire is mainly distributed in the Z direction (vertical direction) of the vehicle, and the excitation of the road surface in the Z direction can be obtained by testing the unevenness of the road surface.

[0131] For example, Figure 4 A schematic diagram of a road surface random excitation test provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, laser probe L1, laser probe L2, laser probe L3 and laser probe L4 are respectively arranged at the middle of the left front wheel, right front wheel, left rear wheel and right rear wheel tires of the test vehicle 3 along the Y direction of the whole vehicle through the clamping device 1 and the clamping device 2. When the test vehicle 3 is traveling at a low speed (it is recommended to keep the speed at about 5km / h), the laser probe L1, laser probe L2, laser probe L3 and laser probe L4 scan the unevenness of the road surface at a certain distance interval (it is recommended to set the distance interval to 5mm), and the unevenness of the driving road surface can be obtained. The road surface unevenness measured by laser probe L1 is shown in FIG. Figure 5shown.

[0132] In some embodiments, the road surface roughness measured by the laser probe L1 is subjected to Fourier transform to obtain the spatial frequency spectrum of the road surface roughness, see Figure 6 shown.

[0133] In some embodiments, the spatial frequency spectrum and the frequency spectrum of the road surface excitation have a relationship as shown in equations (2) and (3):

[0134] f=Ω×V(2)

[0135] P(f)=P(Ω) / V(3)

[0136] Where f is the frequency (Hz), Ω is the spatial circular frequency (cycles / mm), and P(f) is the frequency spectral density or power spectral density (mm 2 / Hz), P(Ω) is the spatial frequency spectral density (mm 2 / cycles / mm), V is the vehicle speed (mm / s).

[0137] It can be understood that by converting equations (2) and (3), the power spectrum density of the road surface excitation can be obtained, see Figure 7 shown.

[0138] It should be noted that the embodiment of the present application only introduces the road surface excitation measured by the laser probe L1. The road surface excitation measured by the laser probes L2-L4 is similar to this, and the embodiment of the present application will not be repeated here.

[0139] In some embodiments, by analyzing the correlation between the road surface excitations measured by the laser probes L1-L4, the cross-spectral density function P between the road surface excitations can be obtained. ij (i,j=1,2,3,4 and i≠j).

[0140] It should be noted that in order to reduce the complexity of the analysis model, the road excitation measured by a laser probe can be used as the autospectral density P of the four tires during the analysis. 11 , P 22 , P 33 , P 44 , the cross-spectral density is set according to the actual test results.

[0141] S302: Tire model testing and modeling.

[0142] In the embodiment of the present application, CDTire (Comfortable and Durability Tire) tire model modeling parameter testing and model fitting can be carried out for the tires configured for the vehicle model, finite element meshing and material parameter settings can be performed on the rim data, and the CDTire tire model and rim model can be assembled and combined. The advantage of using the CDTire tire model is that the model can simulate the dynamic characteristics of tires below 200Hz well, and is suitable for the analysis of vehicle smoothness problems within 80Hz.

[0143] In some embodiments, the assembly combination of the CDTire tire model and the rim model may be carried out based on Hyperworks NVHD software.

[0144] S303. Acquisition and modeling of key parameters of the whole vehicle finite element model.

[0145] In the embodiment of the present application, the finite element model of the whole vehicle can be built, the key parameters of the model can be obtained, the model can be calibrated, and the model can be simplified.

[0146] It should be noted that the finite element model of the whole vehicle includes the vehicle chassis model, body model and powertrain model, etc.

[0147] It should be noted that for the smoothness of the whole vehicle, the key influencing parameters include the mass and center of mass of the powertrain, the dynamic stiffness and damping of the powertrain suspension system, the damping of the suspension shock absorber, the stiffness of the suspension spring, and the dynamic stiffness and damping of the key suspension bushings. Among them, the dynamic stiffness and damping of the powertrain suspension system and the dynamic stiffness and damping of the bushing are the dynamic stiffness and damping of the corresponding working conditions, that is, the force, displacement and frequency applied during the dynamic stiffness and damping test should be consistent with the force, displacement and frequency on the actual vehicle.

[0148] In some embodiments, in the whole vehicle finite element model, the seats have corresponding detailed finite element models, and the occupants are modeled using a concentrated mass model to reflect the impact of the mass boundaries of the seats and occupants on the response of the floor and seat rail mounting points.

[0149] In some embodiments, after the whole vehicle finite element model is constructed, the whole vehicle modal analysis can be performed to check and calibrate the model accuracy.

[0150] It should be noted that for the vehicle's smooth performance, the Hop mode of the suspension in the Z direction and the Bounce mode of the powertrain in the Z direction are two key modes. The vibration directions of these two modes are both along the Z direction, so the modal frequencies are close. The suspension and powertrain resonate, which will greatly affect the vehicle's smooth performance.

[0151] In some embodiments, the Hop modal frequency of the suspension in the Z direction may be calculated using the following formula (4):

[0152]

[0153] Among them, f Hop represents the Hop modal frequency of the suspension in Z direction (Hz), m 悬架 represents the mass of one quarter of the suspension (kg), K 悬架 Indicates the stiffness of the quarter suspension in the Z direction (N / mm), K 轮胎 Indicates the static stiffness of the tire in Z direction (N / mm).

[0154] In some embodiments, the bounce modal frequency of the powertrain in the Z direction may be calculated using the following formula (5):

[0155]

[0156] Among them, f Bounce Represents the Bounce modal frequency of the powertrain in the Z direction (Hz), m 动力 Indicates the mass of the powertrain (kg), K i It represents the static stiffness of the ith suspension in Z direction (N / mm), where n is the number of suspensions, usually n=3 or n=4.

[0157] In some embodiments, the modal frequency results obtained based on the simulation of the whole vehicle finite element model can be compared with the modal frequencies calculated by equations (4) and (5), and the error can be controlled within 0.5 Hz to achieve calibration of the whole vehicle finite element model.

[0158] It should be noted that when evaluating the ride comfort of a vehicle, the vibration frequency range considered is usually 0.5 Hz to 80 Hz. Within this frequency range, the vibration generated during vehicle driving has a significant impact on the comfort of the passengers.

[0159] In some embodiments, after the calibration of the whole vehicle finite element model is completed, super unit models of the chassis and body can be established to simplify the whole vehicle finite element model to improve the subsequent analysis efficiency and compress the whole vehicle level analysis time from hours to minutes.

[0160] S304. Seat-occupant transfer function test.

[0161] It should be noted that, in the embodiment of the present application, the seat-passenger transfer function includes a vibration transfer function from the seat rail mounting point to the top of the seat cushion and a vibration transfer function from the seat rail mounting point to the seat back.

[0162] In some embodiments, the vibration transfer function from the seat rail mounting point to the top of the seat cushion and the seat back with passengers can be tested by experimental methods to serve as the basis for calculating the vibration acceleration response of the top of the seat cushion and the seat back.

[0163] It should be noted that during the vibration transfer function test, the seat can be installed on the vehicle body and the installation boundary should be consistent with that of the actual vehicle. The test response point and test fixture are consistent with the seat response point and test fixture required by the national standard for vehicle smoothness evaluation, and the occupant's sitting posture is also implemented in accordance with the standard requirements. At the same time, considering the impact of different occupants' different weights on the vehicle's smoothness results, during the transfer function test, occupants of different weights can be arranged to ride, and then the seat-occupant vibration transfer function under various conditions can be tested to better match the simulation conditions with the conditions of the actual vehicle test and improve the simulation accuracy.

[0164] For example, the vibration transfer function from the left rear mounting point of the seat rail to the seat back measured in the test is as follows: Figure 8 As shown, from Figure 8 It can be seen that the peak frequency of the vibration transfer function becomes larger and the amplitude decreases significantly when there is a occupant (weighing about 75 kg) than when there is no occupant. This phenomenon cannot be reproduced by the simplified finite element model of the seat-occupant, but the method provided in the embodiment of the present application can well reflect this phenomenon.

[0165] S305, floor-seat rail installation point response simulation optimization.

[0166] In the embodiment of the present application, the vibration acceleration response of the cab floor and the seat rail mounting points can be simulated based on the road surface excitation obtained from the test and the finite element model of the whole vehicle.

[0167] In some embodiments, random excitation can be loaded at the contact points of the four tires in the finite element model of the whole vehicle in accordance with the requirements of the road random excitation simulation condition. Meanwhile, the difference in excitation time of the front and rear tires is considered and a phase difference is introduced in the random excitation. The vibration acceleration response of the cab floor and the vibration acceleration response of the seat rail mounting point can be simulated.

[0168] For example, the simulated spectrum results and test spectrum results of the vibration acceleration response of the left rear mounting point of the driver's seat rail in the Z direction when the vehicle speed is 60 km / h on a rough asphalt road are as follows: Fig. 9 As shown, from Fig. 9 It can be seen that after the whole vehicle finite element model is calibrated, except for some individual frequencies due to inaccurate system damping parameters, the simulation results of the remaining frequency bands are well consistent with the test results in terms of amplitude and trend. The calibrated whole vehicle finite element model can improve the accuracy of vehicle smoothness evaluation.

[0169] S306. Vehicle smoothness simulation optimization.

[0170] In an embodiment of the present application, the vibration acceleration response of the seat rail mounting point obtained by simulation and the vibration transfer function obtained by test can be combined to calculate the vibration acceleration response above the seat cushion and the vibration acceleration response of the seat backrest. Combined with the simulation results of the acceleration vibration response of the cab floor, weighted processing is performed to obtain a vibration acceleration weighted response as an objective indicator for evaluating the smoothness of the entire vehicle.

[0171] S307. Evaluation of vehicle ride comfort.

[0172] In the embodiment of the present application, the smoothness score of the whole vehicle can be comprehensively evaluated based on the vibration acceleration weighted response obtained in S306, and the smoothness score can be output. If the score does not meet the standard, return to S305 to optimize the smoothness based on the finite element model of the whole vehicle until the target is met.

[0173] In some embodiments, the objective index of ride comfort calculated in S306 can be compared with the national standard to obtain the final subjective evaluation result of vehicle ride comfort. If the result does not meet the requirements, it will return to S305 to optimize the response simulation of the floor-seat rail installation point, as well as the parameters of the suspension and powertrain. Of course, it is also possible to decompose the actual problem into seats, optimize the seat structure, and then conduct a seat-occupant transfer function test for the new seat structure. Repeating S306 and S307 can complete the optimization of the seat based on ride comfort.

[0174] For example, based on the rough asphalt road surface and the occupant mass of 75 kg calculated by the finite element model of the whole vehicle, the weighted response of the vibration acceleration of each point on the cab floor, the top of the seat cushion, and the seat back at different vehicle speeds and the calculation results of the comprehensive evaluation index of ride comfort are as follows: Fig.10 As shown, from Fig.10 It can be seen that as the vehicle speed increases, the results of each response point and comprehensive evaluation index increase with the vehicle speed, and the seat cushion has the greatest impact on the overall comprehensive evaluation.

[0175] It is understandable that the embodiment of the present application innovatively skips the complex modeling of the seat and occupant model, and obtains the vibration transfer function through experimental testing, which can not only truly reflect the physical phenomenon, but also reduce the difficulty of implementing the method, improve the versatility of the method, and is applicable to the simulation analysis of the ride comfort performance of all vehicle models. The vehicle ride comfort simulation analysis method provided in the embodiment of the present application has the advantages of strong versatility, comprehensive system and convenient operation, and is suitable for the ride comfort analysis of ordinary fuel vehicles, as well as extended-range and pure electric vehicles.

[0176] It should be noted that, in order to facilitate the rapid implementation of S306 and S307, the present embodiment provides a vehicle ride comfort simulation analysis system, such as Fig.11 As shown, the system includes: a road excitation selection module 1101, a vehicle speed setting module 1102, an occupant mass setting module 1103, a target setting module 1104, a model selection and simulation calculation module 1105, a test vibration transfer function selection module 1106, an objective index calculation and display module 1107, and a subjective index calculation and display module 1108; wherein:

[0177] The road surface excitation selection module 1101 is used to select the road surface excitation of the target road surface to be investigated, and generate the autospectral density function P of the random excitation in combination with the vehicle speed. 11 , P 22 , P 33 , P 44 and the cross-spectral density function P ij (i, j = 1, 2, 3, 4 and i ≠ j);

[0178] The vehicle speed setting module 1102 is used to set the vehicle speed of the analyzed working condition, and the unit can be m / s or km / h;

[0179] The passenger mass setting module 1103 is used to set the passenger mass during the actual vehicle test, which is 75 kg by default;

[0180] A target setting module 1104 is used to set a subjective target for vehicle ride comfort, such as a subjective target of 7.5 points;

[0181] The model selection and simulation calculation module 1105 is used to select the finite element model of the whole vehicle, and calculate the vibration acceleration response of the cab floor and the seat rail installation point in combination with the road excitation, vehicle speed and occupant mass;

[0182] A test vibration transfer function selection module 1106 is used to select a test result of a seat-passenger transfer function, and the passenger mass corresponding to the selected transfer function test result is consistent with the passenger mass set in the passenger mass setting module 1103;

[0183] The objective index calculation and display module 1107 is used to calculate and display the objective index of the vehicle ride comfort based on the settings and calculation results in the model selection and simulation calculation module 1105 and the test vibration transfer function selection module 1106;

[0184] The subjective index calculation and display module 1108 is used to calculate and display the subjective evaluation index of ride comfort according to the objective index calculated by the objective index calculation and display module 1107 and the index requirements in the national standard.

[0185] It can be understood that the embodiment of the present application refines the finite element model of the whole vehicle through the technical approach of simulation + testing, models the suspension and powertrain in detail, examines the transfer characteristics of road excitation, and simulates the vibration acceleration response of the cab floor and the seat rail mounting points. At the same time, based on the requirements for seats and occupants in national standards, the vibration transfer function from the seat rail mounting point to the top of the seat cushion and the seat back in the state with occupants is obtained through experimental testing. Then, combined with the vibration acceleration response of the seat rail mounting point obtained by simulation, the vibration acceleration response of the top of the seat cushion and the seat back is calculated. Finally, the vibration acceleration response of the top of the seat cushion, the seat back and the cab floor is weighted to achieve an accurate evaluation of the vehicle smoothness, which helps to improve the comfort of the whole vehicle and is of great significance for guiding the positive development of vehicle smoothness and seat ride comfort.

[0186] The vehicle smoothness simulation and analysis device provided in an embodiment of the present application is described below. The vehicle smoothness simulation and analysis device described below and the vehicle smoothness simulation and analysis method described above can be referenced to each other.

[0187] Fig.12 A schematic diagram of the structure of a vehicle ride comfort simulation and analysis device provided in an embodiment of the present application is shown in FIG. Fig.12 As shown, the device includes: an obtaining module 1210, a first determining module 1220 and a second determining module 1230; wherein:

[0188] An obtaining module 1210 is used to obtain vibration transfer functions from the seat rail installation point of the vehicle to the upper part of the seat cushion and the seat back, respectively, as well as the vibration acceleration response of the cab floor of the vehicle and the vibration acceleration response of the seat rail installation point;

[0189] A first determination module 1220, configured to determine a vibration acceleration response above the seat cushion and a vibration acceleration response of the seat back based on vibration transfer functions from the seat rail installation point to the upper portion of the seat cushion and the seat back, respectively, and a vibration acceleration response of the seat rail installation point;

[0190] The second determination module 1230 is used to determine the ride comfort of the vehicle based on the vibration acceleration response above the seat cushion, the vibration acceleration response of the seat back, and the vibration acceleration response of the cab floor.

[0191] The vehicle smoothness simulation and analysis device provided in the embodiment of the present application can innovatively skip the complex modeling of the seat and occupant model. By using the vibration transfer function from the seat rail mounting point to the top of the seat cushion and the seat back, as well as the vibration acceleration response of the seat rail mounting point, the vibration acceleration response of the top of the seat cushion and the vibration acceleration response of the seat back can be accurately obtained, which can reflect the real physical phenomenon and improve the accuracy of the vehicle smoothness evaluation.

[0192] In some embodiments, the vibration transfer function is obtained based on experimental testing of a target vehicle finite element model corresponding to the vehicle with occupants of different weights, and the vibration acceleration response of the cab floor and the vibration acceleration response of the seat rail mounting point are obtained based on simulation of the target vehicle finite element model.

[0193] In some embodiments, the apparatus further comprises:

[0194] Construction module, used to construct the initial vehicle finite element model;

[0195] A modal frequency acquisition module, for obtaining, based on the initial vehicle finite element model, a Hop modal simulation frequency of the suspension of the vehicle in the vertical direction and a Bounce modal simulation frequency of the powertrain of the vehicle in the vertical direction; obtaining a Hop modal theoretical calculation frequency of the suspension of the vehicle in the vertical direction and a Bounce modal theoretical calculation frequency of the powertrain of the vehicle in the vertical direction;

[0196] A calibration module is used to calibrate the initial vehicle finite element model based on the Hop modal simulation frequency, the Bounce modal simulation frequency, the Hop modal theoretical calculation frequency and the Bounce modal theoretical calculation frequency to obtain the target vehicle finite element model.

[0197] In some embodiments, the building blocks are further configured to:

[0198] When constructing the initial vehicle finite element model, the occupants are treated equivalently using a concentrated mass model.

[0199] In some embodiments, the apparatus further comprises:

[0200] The simplification module is used to obtain the super unit model of the chassis and body of the vehicle; the super unit model of the chassis and body is used to simplify the calibrated target vehicle finite element model to obtain the simplified target vehicle finite element model.

[0201] In some embodiments, the apparatus further comprises:

[0202] An optimization module is used to obtain target parameters of the initial whole vehicle finite element model; based on the target parameters, the initial whole vehicle finite element model is optimized; wherein the target parameters include at least one of the following: the mass and center of mass of the powertrain, the dynamic stiffness and damping of the powertrain suspension system, the damping of the suspension shock absorber, the stiffness of the suspension spring, and the dynamic stiffness and damping of the suspension bushing.

[0203] In some embodiments, the acquisition module 1210 is also used to: obtain a road surface power spectrum density for reflecting road surface roughness; and simulate and obtain the vibration acceleration response of the cab floor and the vibration acceleration response of the seat rail mounting point based on the road surface power spectrum density and the target vehicle finite element model.

[0204] In some embodiments, the acquisition module 1210 is further used to: obtain road surface roughness test data; perform Fourier transform on the road surface roughness test data to obtain a road surface spatial frequency spectrum; and obtain the road surface power spectrum density based on the road surface spatial frequency spectrum.

[0205] It should be noted here that the above-mentioned vehicle smoothness simulation and analysis device provided in the embodiment of the present application can implement all the method steps implemented in the above-mentioned vehicle smoothness simulation and analysis method embodiment, and can achieve the same technical effect. The parts and beneficial effects of this embodiment that are the same as the method embodiment will not be described in detail here.

[0206] Fig.13 A schematic diagram of the physical structure of an electronic device provided in an embodiment of the present application, such as Fig.13 As shown, the electronic device may include: a processor 1310, a communication interface 1320, a memory 1330 and a communication bus 1340, wherein the processor 1310, the communication interface 1320 and the memory 1330 communicate with each other via the communication bus 1340. The processor 1310 may execute executable data instructions stored in the memory 1330 to implement some or all steps in the vehicle ride comfort simulation analysis method provided in the above embodiments.

[0207] In addition, the executable data instructions stored in the above-mentioned memory 1330 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the embodiment of the present application can be essentially or partly reflected in the form of a software product that contributes to the relevant technology. The software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc. Various media that can store program codes.

[0208] An embodiment of the present application also provides a computer-readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, part or all of the steps in the vehicle smoothness simulation analysis method provided in the above embodiments are implemented.

[0209] An embodiment of the present application also provides a computer program product, which includes a computer program stored in a computer-readable storage medium, and the computer program includes program instructions. When the program instructions are executed by a computer, the computer can execute some or all of the steps in the vehicle smoothness simulation analysis method provided in the above embodiments.

[0210] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Those of ordinary skill in the art may understand and implement it without creative work.

[0211] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the embodiments of the present application may adopt the form of hardware embodiments, software embodiments, or embodiments in combination with software and hardware. Moreover, the embodiments of the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) that contain computer-usable program code.

[0212] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0213] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture including an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0214] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0215] The above description is merely an optional embodiment of the present application and is not intended to limit the protection scope of the present application.

Claims

1. A vehicle ride comfort simulation analysis method, characterized in that: The method comprises: Obtaining vibration transfer functions from the vehicle's seat rail mounting point to the top of the seat cushion and the seat back, respectively, as well as the vibration acceleration response of the vehicle's cab floor and the vibration acceleration response of the seat rail mounting point; Determining the vibration acceleration response of the upper portion of the seat cushion and the vibration acceleration response of the seat back based on the vibration transfer functions from the seat rail mounting point to the upper portion of the seat cushion and the seat back, respectively, and the vibration acceleration response of the seat rail mounting point; The ride performance of the vehicle is determined based on the vibration acceleration response above the seat cushion, the vibration acceleration response of the seat back, and the vibration acceleration response of the cabin floor.

2. The vehicle ride comfort simulation analysis method according to claim 1, characterized in that: The vibration transfer function is obtained based on experimental testing of a target vehicle finite element model corresponding to the vehicle with occupants of different weights, and the vibration acceleration response of the cab floor and the vibration acceleration response of the seat guide rail mounting point are obtained based on simulation of the target vehicle finite element model.

3. The vehicle ride comfort simulation analysis method according to claim 2, characterized in that: The method further comprises: Construct an initial vehicle finite element model; Based on the initial vehicle finite element model, obtaining a Hop modal simulation frequency of the suspension of the vehicle in a vertical direction and a Bounce modal simulation frequency of the powertrain of the vehicle in a vertical direction; Obtaining a Hop modal theoretically calculated frequency of the suspension of the vehicle in the vertical direction and a Bounce modal theoretically calculated frequency of the powertrain of the vehicle in the vertical direction; Based on the Hop modal simulation frequency, the Bounce modal simulation frequency, the Hop modal theoretical calculation frequency and the Bounce modal theoretical calculation frequency, the initial whole vehicle finite element model is calibrated to obtain the target whole vehicle finite element model.

4. The vehicle ride comfort simulation analysis method according to claim 3, characterized in that: The method further comprises: When constructing the initial vehicle finite element model, the occupants are treated equivalently using a concentrated mass model.

5. The vehicle ride comfort simulation analysis method according to claim 3 or 4, characterized in that: After calibrating the initial vehicle finite element model based on the Hop modal simulation frequency, the Bounce modal simulation frequency, the Hop modal theoretical calculation frequency, and the Bounce modal theoretical calculation frequency to obtain the target vehicle finite element model, the method further includes: Obtaining a super unit model of the chassis and body of the vehicle; The calibrated target vehicle finite element model is simplified using the super unit models of the chassis and the vehicle body to obtain a simplified target vehicle finite element model.

6. The vehicle ride comfort simulation analysis method according to claim 3 or 4, characterized in that: Before obtaining the Hop modal simulation frequency of the suspension of the vehicle in the vertical direction and the Bounce modal simulation frequency of the powertrain of the vehicle in the vertical direction based on the initial vehicle finite element model, the method further includes: Obtaining target parameters of the initial vehicle finite element model; Based on the target parameters, optimizing the initial vehicle finite element model; The target parameter includes at least one of the following: The mass and center of mass of the powertrain, the dynamic stiffness and damping of the powertrain suspension system, the damping of the suspension shock absorber, the stiffness of the suspension spring, the dynamic stiffness and damping of the suspension bushing.

7. The vehicle ride comfort simulation analysis method according to any one of claims 2 to 4, characterized in that: Obtaining the vibration acceleration response of the cab floor of the vehicle and the vibration acceleration response of the seat rail mounting point, comprising: Obtaining a road surface power spectrum density for reflecting road surface roughness; Based on the road surface power spectrum density and the target vehicle finite element model, the vibration acceleration response of the cab floor and the vibration acceleration response of the seat rail mounting point are obtained by simulation.

8. The vehicle ride comfort simulation analysis method according to claim 7, characterized in that: The obtaining of the road surface power spectrum density for reflecting the road surface roughness comprises: Obtain road roughness test data; Performing Fourier transformation on the road surface roughness test data to obtain a road surface spatial frequency spectrum; The road surface power spectrum density is obtained based on the road surface spatial frequency spectrum.

9. A vehicle ride comfort simulation and analysis device, characterized in that: The device comprises: An acquisition module, used to obtain vibration transfer functions from a seat rail installation point of a vehicle to an upper portion of a seat cushion and a seat back, respectively, and a vibration acceleration response of a cab floor of the vehicle and a vibration acceleration response of the seat rail installation point; a first determination module, configured to determine a vibration acceleration response above the seat cushion and a vibration acceleration response of the seat back based on vibration transfer functions from the seat rail mounting point to the upper portion of the seat cushion and the seat back, respectively, and a vibration acceleration response of the seat rail mounting point; The second determination module is used to determine the ride comfort of the vehicle based on the vibration acceleration response above the seat cushion, the vibration acceleration response of the seat back, and the vibration acceleration response of the cab floor.

10. An electronic device, characterized in that: include: A memory for storing executable data instructions; A processor is used to implement the vehicle ride comfort simulation analysis method according to any one of claims 1 to 8 when executing the executable data instructions stored in the memory.

11. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the vehicle ride comfort simulation analysis method according to any one of claims 1 to 8 is implemented.

12. A computer program product comprising a computer program or instructions, characterized in that When the computer program or instruction is executed by a processor, the vehicle ride comfort simulation analysis method according to any one of claims 1 to 8 is implemented.

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