Method and device for determining dynamic stiffness of suspension bushing and vibration isolation rate of vibration isolation system

Abstract

The invention provides a method and device for determining the dynamic stiffness of a suspension bush and the vibration isolation rate of a vibration isolation system, a vehicle comprises a power assembly and the suspension bush, the power assembly is connected with the suspension bush, and the method for determining the dynamic stiffness of the suspension bush comprises the steps that nonlinear stiffness performance information of the suspension bush is obtained, and the nonlinear stiffness performance information of the suspension bush is obtained in a simulation environment; according to the nonlinear rigidity performance information of the suspension bushing, the displacement and the load of the suspension bushing under the condition that a preset unit load is applied to the mass center of the power assembly are determined, then the corresponding relation between the displacement and the load is determined according to the displacement and the load of the suspension bushing, and then static rigidity displacement performance information is determined. And determining the dynamic stiffness of the suspension bushing according to a corresponding relationship between the static stiffness displacement performance information and preset dynamic and static stiffness. According to the method, the working conditions of the suspension system can be accurately simulated through simulation analysis in the design stage, the dynamic stiffness of the suspension bushing is obtained, and data support is provided for design of the suspension system.

Description

Technical Field

[0001] The present application relates to the field of vehicle suspension systems, and in particular to a method and device for determining the dynamic stiffness of a suspension bushing and the vibration isolation rate of a vibration isolation system. Background Art

[0002] As the number of vehicles continues to increase, the importance of vibration isolation performance has also increased. Vibration isolation performance refers to the ability of a vehicle to isolate vibrations and shocks from the road during driving. It directly affects the vehicle's comfort, handling stability, durability of vehicle components, and passengers' sense of safety. Among them, the suspension is a key connecting component between the vehicle powertrain and the body. Its main functions include supporting the weight of the powertrain, isolating and attenuating the vibration and noise generated by the powertrain, and limiting the displacement of the powertrain under extreme working conditions. By effectively isolating and attenuating vibrations, the suspension setting helps to improve the vehicle's NVH (Noise, Vibration, Harshness) performance, thereby enhancing the market competitiveness of the vehicle.

[0003] Since the suspension bushing is usually made of rubber material, it has significant nonlinear characteristics. Under actual working conditions, the dynamic stiffness of the bushing will change with the load and frequency, which is difficult to accurately predict. This nonlinear characteristic makes it impossible to accurately obtain the dynamic stiffness of the suspension bushing at the working point in the early stage of suspension development. The suspension bushing can only be installed and verified in the later stage of vehicle design. If the suspension vibration isolation performance does not meet the standard in the later actual vehicle verification, the suspension bushing installation plan is difficult to adjust, affecting the efficiency of vehicle development. Summary of the invention

[0004] In view of the above problems, the embodiments of the present application propose a method and device for determining the dynamic stiffness of a suspension bushing and the vibration isolation rate of a vibration isolation system.

[0005] In a first aspect of the implementation of the present application, a method for determining the dynamic stiffness of a suspension bushing is first provided, wherein the vehicle comprises a powertrain and the suspension bushing, the powertrain is connected to the suspension bushing, and the method comprises:

[0006] Acquiring nonlinear stiffness performance information of the suspension bushing;

[0007] In a simulation environment, determining, based on nonlinear stiffness performance information of the suspension bushing, a displacement of the suspension bushing and a load of the suspension bushing when a preset unit load is applied to the center of mass of the powertrain;

[0008] Determining a corresponding relationship between the displacement and the load according to the displacement of the suspension bushing and the load of the suspension bushing;

[0009] Determining static stiffness displacement performance information according to the corresponding relationship between the displacement and the load;

[0010] The dynamic stiffness of the suspension bushing is determined according to the static stiffness displacement performance information and the preset static and dynamic stiffness correspondence.

[0011] Optionally, determining the static stiffness displacement performance information according to the corresponding relationship between the displacement and the load includes:

[0012] Determining the corresponding relationship between the displacement and the static stiffness according to the corresponding relationship between the displacement and the load and a preset corresponding relationship between the load and the static stiffness;

[0013] The static stiffness displacement performance information is determined according to the corresponding relationship between the displacement and the static stiffness.

[0014] Optionally, the nonlinear stiffness performance information of the suspension bushing includes linear segment performance information, transition segment performance information, and hard limit performance information, and the step of obtaining the nonlinear stiffness performance information of the suspension bushing includes:

[0015] In a simulation environment, obtaining inertia parameters of the powertrain, and constructing a whole vehicle coordinate system for the vehicle, wherein the whole vehicle coordinate system includes coordinate information of the powertrain and coordinate information of the suspension bushing;

[0016] In a simulation environment, determining the linear segment performance information of the suspension bushing according to the inertia parameters of the powertrain, the coordinate information of the powertrain and the coordinate information of the suspension bushing;

[0017] determining the transition section performance information of the suspension bushing according to the gear position corresponding to the vehicle;

[0018] determining the hard limit performance information according to the displacement of the powertrain under a preset working condition of the vehicle;

[0019] The nonlinear stiffness performance information of the suspension bushing is determined according to the linear segment performance information, the transition segment performance information, and the hard limit performance information.

[0020] Optionally, the inertia parameters of the powertrain include the mass of the powertrain and the moment of inertia of the powertrain, and the step of determining the linear segment performance information of the suspension bushing according to the inertia parameters of the powertrain, the coordinate information of the powertrain and the coordinate information of the suspension bushing in a simulation environment includes:

[0021] The vehicle coordinate system also includes the coordinates of the center of mass of the powertrain and the coordinates of the elastic center of the suspension bushing;

[0022] In a simulation environment, determining a static load of the suspension bushing according to the mass of the power assembly, the moment of inertia of the power assembly, the coordinates of the center of mass of the power assembly, and the coordinates of the elastic center of the suspension bushing;

[0023] In a simulation environment, determining an initial static stiffness of the suspension bushing according to a static load of the suspension bushing;

[0024] The linear section performance information of the suspension bushing is determined according to the static load of the suspension bushing and the initial static stiffness of the suspension bushing.

[0025] Optionally, determining the initial static stiffness of the suspension bushing according to the static load of the suspension bushing under a simulation environment includes:

[0026] In a simulation environment, determining a theoretical static stiffness of the suspension bushing according to a static load of the suspension bushing;

[0027] In a simulation environment, determining an initial mode of the suspension bushing and an initial decoupling rate of the suspension bushing according to a theoretical static stiffness of the suspension bushing;

[0028] The theoretical static stiffness of the suspension bushing is adjusted according to the initial mode of the suspension bushing and the initial decoupling rate of the suspension bushing to obtain the initial static stiffness of the suspension bushing.

[0029] Optionally, the method further comprises:

[0030] In a simulation environment, determining a target mode of the suspension bushing and a target decoupling rate of the suspension bushing according to the dynamic stiffness of the suspension bushing;

[0031] Determining a modality change according to the initial modality and the target modality;

[0032] Determining a decoupling rate change according to the initial decoupling rate and the target decoupling rate;

[0033] The modal decoupling rate verification result of the suspension bushing is determined according to the modal change and the decoupling rate change.

[0034] Optionally, determining the corresponding relationship between the displacement and the load according to the displacement of the suspension bushing and the load of the suspension bushing includes:

[0035] Determining an initial corresponding relationship between the displacement and the load according to the displacement of the suspension bushing and the load of the suspension bushing;

[0036] determining a correlation coefficient according to the displacement, the load, and an initial corresponding relationship between the displacement and the load, wherein the correlation coefficient represents a similarity between the displacement and the load and the corresponding relationship between the displacement and the load;

[0037] If the correlation coefficient is greater than a preset threshold, the initial corresponding relationship between the displacement and the load is used as the corresponding relationship between the displacement and the load.

[0038] Optionally, the vehicle further comprises a frame, the powertrain is connected to the frame via the suspension bushing, the powertrain, the frame and a plurality of the suspension bushings constitute a vibration isolation system, and the method further comprises:

[0039] In a simulation environment, when the preset unit load is applied to the suspension active side connection point and the suspension passive side connection point, the dynamic stiffness of the suspension active side connection point and the dynamic stiffness of the suspension passive side connection point are determined respectively, wherein the suspension active side connection point is the connection point between the suspension bushing and the powertrain, and the suspension passive side connection point is the connection point between the suspension bushing and the vehicle frame;

[0040] The vibration isolation rate of the vibration isolation system is determined according to the dynamic stiffness of the connection point on the active side of the suspension, the dynamic stiffness of the connection point on the passive side of the suspension, and the dynamic stiffness of the suspension bushing.

[0041] In a second aspect of the implementation of the present application, a method for determining a vibration isolation rate of a vibration isolation system is also provided, wherein the vibration isolation system comprises a powertrain, a frame, and a plurality of suspension bushings, the powertrain and the frame are connected via the suspension bushings, and the method comprises:

[0042] In a simulation environment, when a preset unit load is applied to a suspension active side connection point and a suspension passive side connection point, the dynamic stiffness of the suspension active side connection point and the dynamic stiffness of the suspension passive side connection point are determined respectively, wherein the suspension active side connection point is a connection point between the suspension bushing and the powertrain, and the suspension passive side connection point is a connection point between the suspension bushing and the vehicle frame;

[0043] The vibration isolation rate of the vibration isolation system is determined according to the dynamic stiffness of the connection point on the active side of the suspension, the dynamic stiffness of the connection point on the passive side of the suspension, and the dynamic stiffness of the suspension bushing, wherein the dynamic stiffness of the suspension bushing is determined using the method for determining the dynamic stiffness of the suspension bushing as described above.

[0044] In a third aspect of the implementation of the present application, there is also provided a device for determining the dynamic stiffness of a suspension bushing, characterized in that the vehicle comprises a powertrain and the suspension bushing, the powertrain is connected to the suspension bushing, and the device comprises:

[0045] An information acquisition module, used to acquire nonlinear stiffness performance information of the suspension bushing;

[0046] a displacement load determination module, for determining, in a simulation environment, the displacement of the suspension bushing and the load of the suspension bushing when a preset unit load is applied to the center of mass of the powertrain according to the nonlinear stiffness performance information of the suspension bushing;

[0047] A displacement-load correspondence determination module, used to determine the correspondence between the displacement and the load according to the displacement of the suspension bushing and the load of the suspension bushing;

[0048] A static stiffness displacement performance information determination module, used to determine the static stiffness displacement performance information according to the corresponding relationship between the displacement and the load;

[0049] The suspension bushing dynamic stiffness determination module is used to determine the suspension bushing dynamic stiffness according to the static stiffness displacement performance information and the preset static and dynamic stiffness correspondence relationship.

[0050] In a fourth aspect of the implementation of the present application, a device for determining a vibration isolation rate of a vibration isolation system is also provided, characterized in that the vibration isolation system includes a powertrain, a frame, and a plurality of suspension bushings, the powertrain and the frame are connected through the suspension bushings, and the device includes:

[0051] A connection point dynamic stiffness determination module, used for determining the dynamic stiffness of the connection point on the active side of the suspension and the dynamic stiffness of the connection point on the passive side of the suspension respectively under a simulation environment, when a preset unit load is applied to the connection point on the active side of the suspension and the connection point on the passive side of the suspension, wherein the connection point on the active side of the suspension is the connection point between the suspension bushing and the powertrain, and the connection point on the passive side of the suspension is the connection point between the suspension bushing and the vehicle frame;

[0052] The vibration isolation rate determination module is used to determine the vibration isolation rate of the vibration isolation system according to the dynamic stiffness of the connection point of the active side of the suspension, the dynamic stiffness of the connection point of the passive side of the suspension, and the dynamic stiffness of the suspension bushing, wherein the dynamic stiffness of the suspension bushing is determined using the method for determining the dynamic stiffness of the suspension bushing as described above.

[0053] In the fifth aspect of the implementation of the present application, there is also provided an electronic device, characterized in that it includes a processor, a memory, and a computer program stored in the memory and capable of running on the processor, and when the computer program is executed by the processor, it implements the method for determining the dynamic stiffness of the suspension bushing as described above or the method for determining the vibration isolation rate of the vibration isolation system as described above.

[0054] In the sixth aspect of the implementation of the present application, a computer-readable storage medium is also provided, characterized in that a computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, the method for determining the dynamic stiffness of the suspension bushing as described above or the method for determining the vibration isolation rate of the vibration isolation system as described above is implemented.

[0055] The embodiments of the present application have the following advantages:

[0056] In the embodiment of the present application, by obtaining the nonlinear stiffness performance information of the suspension bushing, and in a simulation environment, according to the nonlinear stiffness performance information of the suspension bushing, the displacement of the suspension bushing and the load of the suspension bushing are determined when a preset unit load is applied to the center of mass of the powertrain, the corresponding relationship between the displacement and the load is determined according to the displacement of the suspension bushing and the load of the suspension bushing, and then according to the corresponding relationship between the displacement and the load, the static stiffness displacement performance information is determined, and the dynamic stiffness of the suspension bushing is determined according to the static stiffness displacement performance information and the preset static and dynamic stiffness correspondence. The present application can accurately simulate the working conditions of the suspension system through simulation analysis in the design stage, thereby efficiently evaluating the dynamic stiffness of the suspension bushing, avoiding the situation where the suspension performance can only be verified by vehicle installation, saving testing time and cost, and providing strong data support for the optimal design of the suspension system. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art.

[0058] Figure 1 is a flowchart of a method for determining the dynamic stiffness of a suspension bushing provided in one embodiment of the present application;

[0059] Figure 2 It is a flowchart of the steps of a method for determining a vibration isolation rate of a vibration isolation system provided in one embodiment of the present application;

[0060] Figure 3 It is a structural schematic diagram of a vibration isolation system provided by an embodiment of the present application;

[0061] Figure 4 It is a structural schematic diagram of a suspension bushing provided in one embodiment of the present application;

[0062] Figure 5 It is a structural schematic diagram of a device for determining the dynamic stiffness of a suspension bushing provided in one embodiment of the present application;

[0063] Figure 6 It is a structural schematic diagram of a device for determining a vibration isolation rate of a vibration isolation system provided in one embodiment of the present application.

[0064] Reference numerals:

[0065] 1-suspension, 2-passive side bracket, 3-motor assembly, 4-active side bracket, 5-subframe, 6-outer liner, 7-linear segment, 8-active side inner liner, 9-rubber main spring, 10-soft limit rubber bumper. DETAILED DESCRIPTION

[0066] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, each embodiment of the present application will be described in detail below in conjunction with the accompanying drawings. However, it will be appreciated by those skilled in the art that in each embodiment of the present application, many technical details are proposed in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed in the present application can also be implemented. The division of the following embodiments is for the convenience of description, and the specific implementation of the present application should not constitute any limitation, and the various embodiments can be combined with each other and referenced to each other without contradiction.

[0067] The suspension is an important force transmission component that fixes the powertrain on the car. Its main function is to support, isolate and attenuate the transmission of the vibration and noise of the powertrain into the car, limit the displacement of the powertrain under extreme working conditions, thereby ensuring good NVH (Noise, Vibration, Harshness) performance in the car and improving the competitiveness of the whole vehicle. The vibration isolation performance of the suspension is mainly evaluated by the vibration isolation rate, which is mainly related to the vibration isolation system composed of the dynamic stiffness of the active side attachment point of the suspension, the dynamic stiffness of the working point of the suspension bushing and the dynamic stiffness of the passive side attachment point of the suspension. Among them, the dynamic stiffness of the active side attachment point of the suspension and the dynamic stiffness of the passive side attachment point can be calculated by CAE (Computer-Aided Enginee ring) simulation software, but due to the nonlinear characteristics of the rubber bushing, the dynamic stiffness of the working point of the suspension bushing cannot be accurately obtained, which further leads to the inability to judge the vibration isolation performance of the suspension during development and design, and can only be verified in the later stage of vehicle installation. Therefore, how to obtain the suspension working point dynamic stiffness under different working conditions in the early stage of suspension development is of great significance for evaluating the suspension vibration isolation performance.

[0068] It should be noted that the suspension may refer to a device used to connect the powertrain (such as the engine and transmission) to the chassis or body of the vehicle. The main function of the suspension is to support the weight of the powertrain, while isolating and absorbing the vibration and noise from the powertrain to improve the NVH (Noise, Vibration, Harshness) performance of the vehicle. The suspension system is usually composed of a suspension bushing and a metal bracket for fixing the suspension bushing. The design of the suspension system is crucial to ensure the driving comfort, handling stability and durability of the powertrain of the vehicle. In an embodiment of the present application, the vibration isolation rate of the vehicle vibration isolation system is determined by calculating the dynamic stiffness of the suspension working point. Among them, the suspension working point may refer to the suspension bushing, and the dynamic stiffness of the suspension working point may be the dynamic stiffness of the suspension bushing.

[0069] Powertrain may refer to the core system of automobiles and other motor vehicles, which is responsible for converting the chemical energy of fuel into mechanical energy, or converting electrical energy into mechanical energy, thereby driving the vehicle forward. In the embodiment of the present application, the powertrain may be connected to the active side of the suspension.

[0070] Reference Figure 1 , showing a step flow chart of a method for determining the dynamic stiffness of a suspension bushing provided in an embodiment of the present application, wherein a vehicle includes a powertrain and the suspension bushing, and the powertrain is connected to the suspension bushing.

[0071] The method may specifically include the following steps:

[0072] Step 101: Obtain nonlinear stiffness performance information of the suspension bushing.

[0073] It should be noted that the nonlinear stiffness performance information of the suspension bushing may be a nonlinear stiffness curve of the suspension bushing. The nonlinear stiffness curve describes the stiffness change of the suspension bushing under different loads. This change is not constant, but changes with the increase or decrease of the load. In the embodiment of the present application, the nonlinear stiffness performance information of the suspension bushing is a nonlinear stiffness curve preliminarily designed based on the existing information.

[0074] In the embodiment of the present application, the nonlinear stiffness performance information of the suspension bushing can be obtained, thereby realizing the simulation analysis of the suspension bushing.

[0075] Step 102 : in a simulation environment, according to the nonlinear stiffness performance information of the suspension bushing, determining the displacement of the suspension bushing and the load of the suspension bushing when a preset unit load is applied to the center of mass of the powertrain.

[0076] It should be noted that the simulation environment may refer to a computer system or software platform used to simulate real-world conditions or system behaviors. In the embodiments of the present application, simulation of different data may be achieved through a variety of simulation platforms.

[0077] In the field of engineering, unit load may refer to a standardized force or moment applied to a structure or system for the purpose of structural analysis and design. In the embodiment of the present application, the simulation of the actual installation of the suspension bushing may be achieved by applying a unit load to the center of mass of the powertrain.

[0078] The center of mass of a powertrain can be referred to as the average location of all masses in the powertrain system. In automotive engineering, the center of mass of a powertrain is an important parameter because it affects the handling, stability, and balance of the vehicle. The location of the center of mass of a powertrain is usually determined by the mass and geometric layout of its individual components, including the engine, transmission, clutch, drive shaft, etc.

[0079] In the embodiment of the present application, the displacement and load of the suspension bushing can be determined in a simulation environment based on the nonlinear stiffness performance information of the suspension bushing when a preset unit load is applied to the center of mass of the powertrain, wherein the applied load can correspond to different working conditions of the vehicle.

[0080] In a specific implementation, the displacement of the suspension bushing and the load of the suspension bushing obtained may be the stress conditions of each suspension under typical working conditions, as shown in Table 1:

[0081] Table 1 Stress conditions of each suspension under typical working conditions

[0082]

[0083] The main direction W refers to the W axis in the vehicle coordinate system where the suspension system analysis model is located.

[0084] In a specific implementation, after obtaining the nonlinear stiffness curve preliminarily designed based on the existing information, it can be substituted into the suspension system analysis model, and a load can be applied at the center of mass of the powertrain. By applying different loads, the suspension displacement and force under different working conditions can be obtained.

[0085] Among them, the suspension system analysis model can be built based on Adams (Automatic Dynamic Analysis of Mechanical Systems) simulation software, which allows engineers and designers to simulate and analyze the motion and dynamic behavior of complex mechanical systems under real-world conditions. The suspension system analysis model in the embodiment of the present application can be established based on a powertrain and several suspensions. In addition, Adams can be co-simulated with other CAE software (such as finite element analysis software, control systems, and multi-physics field simulation software) to perform a more comprehensive system-level analysis.

[0086] Step 103, determining a corresponding relationship between the displacement and the load according to the displacement of the suspension bushing and the load of the suspension bushing;

[0087] In the embodiment of the present application, the corresponding relationship between the displacement and the load can be determined according to the displacement of the suspension bushing and the load of the suspension bushing. The displacement of the suspension bushing and the load of the suspension bushing can be the displacement and load of the same suspension bushing under the same working condition, and the corresponding relationship between the displacement and the load can be embodied in the form of a function.

[0088] In a specific implementation, the nonlinear stiffness curve data of the rear suspension can be taken as an example to design the nonlinear stiffness curve of the rear suspension. The nonlinear stiffness curve data of the rear suspension is shown in Table 2:

[0089] Table 2 Nonlinear stiffness curve data of rear suspension

[0090]

[0091] In a specific implementation, the nonlinear stiffness curve of the rear suspension may be plotted according to the nonlinear stiffness curve data of the rear suspension, and the data may be curve fitted to obtain the fitting function relationship of the suspension load-displacement curve.

[0092] The functional relationship obtained after fitting the above rear suspension nonlinear stiffness curve is as follows:

[0093] y=0.0646x 5 -5×10 -11 x 4 +0.877x 3 -1×10 -7 x 2 +287.62x+8×10 -6

[0094] Wherein, x represents displacement, and y represents load. It should be noted that the above formula is only an exemplary functional relationship obtained by curve fitting using the nonlinear stiffness curve of the rear suspension as an example. The present application can also obtain data of other suspensions under other working conditions and then perform curve fitting.

[0095] Step 104: Determine static stiffness displacement performance information according to the corresponding relationship between the displacement and the load.

[0096] It should be noted that the static stiffness-displacement performance information can be a suspension stiffness-displacement curve, which describes the stiffness characteristics of the suspension system under static load, that is, the static stiffness of the suspension at different displacement levels. The static stiffness-displacement curve is an important tool for evaluating the performance of the suspension system when designing and optimizing the suspension system.

[0097] In the embodiment of the present application, the static stiffness displacement performance information can be determined according to the corresponding relationship between the displacement and the load.

[0098] Step 105: Determine the dynamic stiffness of the suspension bushing according to the static stiffness displacement performance information and the preset static and dynamic stiffness correspondence relationship.

[0099] It should be noted that the preset dynamic and static stiffness correspondence relationship may be a dynamic and static stiffness conversion formula, and the dynamic and static stiffness conversion formula is as follows:

[0100] K d =α·K s

[0101] Among them, K d is the dynamic stiffness, K s is the static stiffness, and α is the dynamic-static ratio conversion coefficient. The dynamic-static ratio conversion coefficient can be selected according to actual conditions. The dynamic-static ratio of the rubber mount can be 1.4, and the dynamic-static ratio of the hydraulic mount can be 1.6.

[0102] The dynamic stiffness of the suspension bushing may refer to the stiffness characteristics of the suspension bushing under the action of a dynamic load, and the dynamic stiffness may describe the stiffness response of the bushing under the action of a dynamic load.

[0103] In the embodiment of the present application, the dynamic stiffness of the suspension bushing can be determined according to the static stiffness displacement performance information and the preset correspondence between static and dynamic stiffness.

[0104] The embodiment of the present application can accurately determine the dynamic stiffness of the suspension bushing under dynamic load by utilizing the static stiffness displacement performance information and the preset static and dynamic stiffness correspondence. This method not only simplifies the calculation process of dynamic stiffness, but also improves the accuracy and efficiency of the calculation. By using the dynamic and static stiffness conversion formula and selecting the appropriate dynamic-static ratio conversion coefficient according to actual conditions, it can better adapt to different types of suspension bushings (such as rubber suspension and hydraulic suspension), thereby providing strong data support for the design and optimization of the suspension system. This method based on the static stiffness displacement performance information and the preset static and dynamic stiffness correspondence helps engineers to accurately evaluate the dynamic stiffness of the suspension bushing during the design stage, thereby optimizing the vibration isolation performance of the suspension system and improving the NVH performance of the vehicle.

[0105] And in a specific implementation, the dynamic stiffness of each suspension bushing under different working conditions can be obtained based on the static stiffness displacement performance information under different working conditions and the preset static and dynamic stiffness correspondence relationship.

[0106] The dynamic stiffness of each suspension bushing may be the dynamic stiffness characteristic of the suspension system under specific working conditions. The obtained dynamic stiffness of each suspension bushing is shown in Table 3:

[0107] Table 3 Dynamic stiffness of each mount under typical working conditions

[0108]

[0109] In the embodiment of the present application, by obtaining the nonlinear stiffness performance information of the suspension bushing, and in a simulation environment, according to the nonlinear stiffness performance information of the suspension bushing, the displacement of the suspension bushing and the load of the suspension bushing are determined when a preset unit load is applied to the center of mass of the powertrain, the corresponding relationship between the displacement and the load is determined according to the displacement of the suspension bushing and the load of the suspension bushing, and then according to the corresponding relationship between the displacement and the load, the static stiffness displacement performance information is determined, and the dynamic stiffness of the suspension bushing is determined according to the static stiffness displacement performance information and the preset static and dynamic stiffness correspondence. The present application can accurately simulate the working conditions of the suspension system through simulation analysis in the design stage, thereby efficiently evaluating the dynamic stiffness of the suspension bushing, avoiding the situation where the suspension performance can only be verified by vehicle installation, saving testing time and cost, and providing strong data support for the optimal design of the suspension system.

[0110] In an optional embodiment of the present application, step 104 further includes the following sub-steps:

[0111] S11: determining the correspondence relationship between the displacement and the static stiffness according to the correspondence relationship between the displacement and the load and a preset load static stiffness correspondence relationship;

[0112] S12: Determine static stiffness displacement performance information according to the corresponding relationship between the displacement and the static stiffness.

[0113] It should be noted that the load-static stiffness correspondence may refer to the relationship between the stiffness of a structure or material and the load it is subjected to under a static load. In the embodiment of the present application, under a static load, the static stiffness of the suspension may be expressed as a ratio of load to displacement.

[0114] It should be noted that the corresponding relationship between displacement and static stiffness refers to the relationship between the displacement of the suspension and its static stiffness under the action of static load.

[0115] In the embodiment of the present application, the correspondence between displacement and static stiffness can be determined according to the correspondence between displacement and load and the preset load static stiffness correspondence, and then the static stiffness displacement performance information can be determined according to the correspondence between displacement and static stiffness. Among them, the displacement of the suspension bushing and the static stiffness of the suspension bushing can be the displacement and static stiffness of the same suspension bushing under the same working condition, and the correspondence between the displacement and the static stiffness can be embodied in the form of a function.

[0116] In a specific implementation, the above fitting polynomial can be derived according to the above rear suspension nonlinear stiffness curve, and its derivative is the suspension stiffness. At the same time, the stiffness of the suspension working point can also be calculated through this derivative. The function relationship obtained after the derivation is as follows:

[0117] y'=5×0.0646x 4 -5×4×10- 11 x 3 +3×0.877x 3 -2×10- 7 x

[0118] Wherein, x represents displacement, and y' represents static stiffness. It should be noted that the above formula is only an exemplary functional relationship obtained by taking the nonlinear stiffness curve of the rear suspension as an example, and the present application can also obtain the corresponding relationship of other suspensions under other working conditions and then perform derivation.

[0119] In an optional embodiment of the present application, the nonlinear stiffness performance information of the suspension bushing includes linear segment performance information, transition segment performance information, and hard limit performance information, and step 101 further includes the following sub-steps:

[0120] S21: in a simulation environment, obtaining inertia parameters of the powertrain, and constructing a whole vehicle coordinate system for the vehicle, wherein the whole vehicle coordinate system includes coordinate information of the powertrain and coordinate information of the suspension bushing;

[0121] S22: in a simulation environment, determining the linear segment performance information of the suspension bushing according to the inertia parameter of the powertrain, the coordinate information of the powertrain and the coordinate information of the suspension bushing;

[0122] S23: determining the transition section performance information of the suspension bushing according to the gear position corresponding to the vehicle;

[0123] S24: determining the hard limit performance information according to the displacement of the power assembly under the preset working condition of the vehicle;

[0124] S25: Determine the nonlinear stiffness performance information of the suspension bushing according to the linear segment performance information, the transition segment performance information, and the hard limit performance information.

[0125] It should be noted that the inertia parameters of the powertrain can be the mass of the powertrain and the moment of inertia of the powertrain. Among them, the mass of the powertrain can refer to the total weight of all components of the powertrain. Mass is the main factor affecting the inertia of the powertrain in linear motion. A larger mass means that more force is required when accelerating or decelerating, and it also means that the powertrain will generate greater inertial force under vibration and impact. Among them, the moment of inertia can refer to the inertial characteristics of the powertrain in rotational motion. It describes the ability of the powertrain to resist rotation, that is, the difficulty of changing its rotation speed under a given torque. The moment of inertia depends on the mass distribution of the powertrain, in particular, the distribution of the mass relative to the axis of rotation. The farther the mass distribution is from the axis of rotation, the greater the moment of inertia. In an embodiment of the present application, the linear segment performance information can be determined based on the mass of the powertrain, the moment of inertia of the powertrain and other information.

[0126] It should be noted that the nonlinear stiffness performance information of the suspension bushing refers to the stiffness characteristics of the suspension bushing under different load and displacement conditions. These characteristics usually include linear segment performance information, transition segment performance information and hard limit performance information, which are combined to describe the stiffness response of the suspension bushing under different working conditions.

[0127] The linear segment performance information can describe the stiffness characteristics of the suspension bushing within a smaller load and displacement range. Within this range, the stiffness of the suspension bushing is constant, that is, the load is proportional to the displacement. The linear segment performance information is usually determined by experimental testing or theoretical analysis, and is used in the design stage to predict the behavior of the suspension bushing under normal working conditions. In an embodiment of the present application, the linear segment performance information can be a linear segment of the suspension nonlinear stiffness curve.

[0128] The transition section performance information can describe the transition behavior of the suspension bushing from the linear section to the nonlinear section. Within this range, the stiffness of the suspension bushing begins to change with the change of load and displacement, and no longer remains constant. The transition section performance information is crucial to understanding the behavior of the suspension bushing under large load and displacement conditions, especially when designing a suspension system that needs to consider extreme working conditions. In an embodiment of the present application, the transition section performance information can be the transition section of the suspension nonlinear stiffness curve.

[0129] The hard limit performance information may describe the stiffness characteristics of the suspension bushing when it reaches its physical limit. In this range, the stiffness of the suspension bushing increases dramatically because the bushing material or structure begins to plastically deform or contact the hard limit device. The hard limit performance information is very important to ensure the safety and reliability of the suspension bushing under extreme working conditions. In an embodiment of the present application, the hard limit performance information may be the hard limit of the suspension nonlinear stiffness curve.

[0130] In an embodiment of the present application, the inertia parameters of the powertrain can be obtained in a simulation environment, and a whole vehicle coordinate system can be constructed for the vehicle, the whole vehicle coordinate system including the coordinate information of the powertrain and the coordinate information of the suspension bushing. In the simulation environment, the linear segment performance information of the suspension bushing is determined based on the inertia parameters of the powertrain, the coordinate information of the powertrain and the coordinate information of the suspension bushing, and then the transition segment performance information of the suspension bushing is determined based on the corresponding gear position of the vehicle. The hard limit performance information is determined based on the displacement of the powertrain under the preset working conditions of the vehicle, and the nonlinear stiffness performance information of the suspension bushing is determined based on the linear segment performance information, the transition segment performance information and the hard limit performance information.

[0131] In specific implementation, the main purpose of suspension nonlinear stiffness design is to achieve good vibration isolation and limiting effects, which mainly includes three aspects: linear section design, transition section design and hard limit design. The design can be carried out in the following ways:

[0132] Linear segment design: First, the static load distributed to each suspension is calculated based on the powertrain mass, moment of inertia, suspension elastic center and powertrain mass center coordinates in the vehicle coordinate system. Then, the static stiffness of the suspension is preliminarily determined with the decoupling rate and modal frequency as optimization targets. Finally, the static sinkage, i.e., displacement, can be obtained based on the ratio of static load to static stiffness.

[0133] Transition performance information design: The key to transition design is to determine the "turning point" from the linear region to the nonlinear region. For general cars, the 3rd gear full throttle acceleration condition is usually designed to just "enter" the nonlinear region. Since the transmission ratio of 1st and 2nd gear is greater than that of 3rd gear, the 1st and 2nd gear full throttle acceleration conditions will inevitably "fall" into the nonlinear region.

[0134] Hard limit design: Automobile driving conditions are complex. According to the 28 load conditions for North America in General Motors' specification GMW14116, the limit conditions for the front and rear movement of the powertrain are 11g, 5g vertically, and 3g laterally. These limit conditions will cause excessive displacement of the powertrain and easily interfere with surrounding components. Therefore, the purpose of hard limit section design is to ensure that the limit stiffness of each suspension is not too large to prevent abnormal noise and vibration problems under high load; try to make two suspensions participate in the limit at the same time to prevent excessive load when a single suspension is limited; avoid metal-to-metal limit design.

[0135] In an optional embodiment of the present application, the inertia parameter of the powertrain includes the mass of the powertrain and the moment of inertia of the powertrain, and step S22 further includes the following sub-steps:

[0136] S31: The whole vehicle coordinate system also includes the coordinates of the center of mass of the powertrain and the coordinates of the elastic center of the suspension bushing;

[0137] S32: in a simulation environment, determining a static load of the suspension bushing according to the mass of the power assembly, the moment of inertia of the power assembly, the center of mass coordinates of the power assembly, and the elastic center coordinates of the suspension bushing;

[0138] S33: Under a simulation environment, determining an initial static stiffness of the suspension bushing according to a static load of the suspension bushing;

[0139] S34: Determine the linear segment performance information of the suspension bushing according to the static load of the suspension bushing and the initial static stiffness of the suspension bushing.

[0140] It should be noted that the center of mass coordinates of a powertrain may refer to the average position of all masses in the powertrain system, that is, the coordinates of the center of mass (COM) in three-dimensional space. In vehicle engineering, the center of mass position of a powertrain may affect the handling, stability and balance of the vehicle.

[0141] The elastic center coordinates of the suspension bushing may refer to the location of the neutral point or equilibrium point of the elastic deformation of the suspension bushing when subjected to a load. The elastic center is a theoretical point at which the stiffness matrix of the suspension bushing is symmetrical and the deformation of the bushing under load does not produce torque or torsion.

[0142] In an embodiment of the present application, the vehicle coordinate system may also include the center of mass coordinates of the powertrain and the elastic center coordinates of the suspension bushing, wherein the center of mass coordinates of the powertrain and the elastic center coordinates of the suspension bushing may be obtained in the suspension system analysis model.

[0143] In the embodiment of the present application, the static load of the suspension bushing can be determined in a simulation environment according to the mass of the powertrain, the moment of inertia of the powertrain, the center of mass coordinates of the powertrain, and the elastic center coordinates of the suspension bushing. Then, in the simulation environment, the initial static stiffness of the suspension bushing is determined according to the static load of the suspension bushing, wherein the initial static stiffness can be obtained according to the analysis model of the suspension system. Then, the linear segment performance information of the suspension bushing is determined according to the static load of the suspension bushing and the initial static stiffness of the suspension bushing.

[0144] In specific implementation, the static load distributed to each suspension can be calculated based on the powertrain mass, moment of inertia, suspension elastic center and powertrain mass center coordinates in the vehicle coordinate system. Then, the static stiffness is obtained, and the static sinking, i.e., displacement, can be obtained based on the ratio of static load to static stiffness.

[0145] In an optional embodiment of the present application, step S33 further includes the following sub-steps:

[0146] S41: determining the theoretical static stiffness of the suspension bushing according to the static load of the suspension bushing in a simulation environment;

[0147] S42: Under a simulation environment, determining an initial mode of the suspension bushing and an initial decoupling rate of the suspension bushing according to a theoretical static stiffness of the suspension bushing;

[0148] S43: adjusting the theoretical static stiffness of the suspension bushing according to the initial mode of the suspension bushing and the initial decoupling rate of the suspension bushing to obtain the initial static stiffness of the suspension bushing.

[0149] It should be noted that static stiffness may refer to the stiffness characteristics of a structure or material under a static load. In the embodiment of the present application, the theoretical static stiffness may be the static stiffness of the suspension bushing obtained based on the suspension system analysis model based on the static load.

[0150] The mode can be a vibration mode or natural frequency of the suspension. Each mode corresponds to a specific vibration mode of the suspension, and these modes are determined by the physical properties of the system (such as mass, stiffness and damping). In an embodiment of the present application, the initial mode can be a mode determined according to the theoretical static stiffness.

[0151] The decoupling rate may be the degree of coupling between different vibration modes in a system. The decoupling rate is an indicator for measuring the independence of the vibration modes of a system, which indicates the degree of mutual influence between the vibration modes in the system. The higher the decoupling rate, the more independent the vibration modes in the system are and the less influence they have on each other. In an embodiment of the present application, the initial decoupling rate may be a decoupling rate determined according to the theoretical static stiffness.

[0152] In an embodiment of the present application, the theoretical static stiffness of the suspension bushing can be determined according to the static load of the suspension bushing based on the suspension system analysis model in a simulation environment. Then, the initial mode of the suspension bushing and the initial decoupling rate of the suspension bushing can be determined according to the theoretical static stiffness of the suspension bushing based on the suspension system analysis model in the simulation environment. Then, the theoretical static stiffness of the suspension bushing can be adjusted according to the initial mode of the suspension bushing and the initial decoupling rate of the suspension bushing to obtain the initial static stiffness of the suspension bushing.

[0153] In specific implementation, the decoupling rate and modal frequency can be used as optimization targets to preliminarily determine the static stiffness of the suspension.

[0154] In an optional embodiment of the present application, the method further includes:

[0155] S51: Under a simulation environment, determining a target mode of the suspension bushing and a target decoupling rate of the suspension bushing according to the dynamic stiffness of the suspension bushing;

[0156] S52: determining a modality change according to the initial modality and the target modality;

[0157] S53: determining a change in the decoupling rate according to the initial decoupling rate and the target decoupling rate;

[0158] S54: Determine a modal decoupling rate verification result of the suspension bushing according to the modal change and the decoupling rate change.

[0159] It should be noted that the target mode may be a mode determined according to the dynamic stiffness of the suspension bushing based on the suspension system analysis model. The target decoupling rate may be a decoupling rate determined according to the dynamic stiffness of the suspension bushing based on the suspension system analysis model.

[0160] The modal change may be a difference between an initial mode and a target mode, and the decoupling rate change may be a difference between an initial decoupling rate and a target decoupling rate.

[0161] The modal decoupling rate verification result can refer to the result of verifying and evaluating the coupling degree between the vibration modes of the system after modal analysis and decoupling rate calculation. The modal decoupling rate verification result can help engineers confirm whether the vibration modes of the system are independent enough, thereby optimizing the dynamic performance and vibration control of the system.

[0162] In an embodiment of the present application, in a simulation environment, based on the suspension system analysis model, the target mode of the suspension bushing and the target decoupling rate of the suspension bushing can be determined according to the dynamic stiffness of the suspension bushing, and then the modal change can be determined according to the initial mode and the target mode, and the decoupling rate change can be determined according to the initial decoupling rate and the target decoupling rate. Finally, the modal decoupling rate verification result of the suspension bushing can be determined according to the modal change and the decoupling rate change.

[0163] Among them, the suspension system analysis model may include but is not limited to the powertrain mass, moment of inertia, suspension elastic center and powertrain center of mass coordinates, suspension installation angle, and motor performance parameters in the vehicle coordinate system.

[0164] It should be noted that the suspension installation angle may be the installation angle of each suspension in the vehicle coordinate system.

[0165] The motor performance parameters may include the main reducer speed ratio, the maximum torque of the drive motor, and the maximum energy recovery torque during coasting.

[0166] The final reducer speed ratio can be the reduction ratio between the drive shaft (usually the rear axle or the front axle) and the output shaft of the drive motor. It determines the relationship between the speed of the drive motor and the speed of the wheels. A higher speed ratio means that the drive motor can provide higher torque at a lower speed, thereby improving the vehicle's acceleration performance and climbing ability.

[0167] The maximum torque of the drive motor refers to the maximum torque that the drive motor can provide in a short period of time. This parameter determines the dynamic performance of the vehicle during acceleration and climbing. The higher the maximum torque of the drive motor, the faster the vehicle responds when starting and accelerating, and the stronger its climbing ability.

[0168] The maximum energy recovery torque during coasting may refer to the maximum torque that the drive motor can recover when the vehicle is coasting or braking. The energy recovery system converts the rotational kinetic energy of the drive motor into electrical energy and stores it in the battery, thereby extending the vehicle's range. The higher the maximum energy recovery torque during coasting, the more energy the vehicle can recover during coasting and braking, thereby improving energy efficiency.

[0169] In the specific implementation, it is possible to confirm whether parameters such as the modal decoupling rate of the suspension system have changed under dynamic conditions and the specific amount of change, so as to optimize the dynamic performance and vibration control of the system based on this.

[0170] In an optional embodiment of the present application, step 103 further includes the following sub-steps:

[0171] S61: determining an initial corresponding relationship between the displacement and the load according to the displacement of the suspension bushing and the load of the suspension bushing;

[0172] S62: determining a correlation coefficient according to the displacement, the load, and an initial corresponding relationship between the displacement and the load, wherein the correlation coefficient represents a similarity between the displacement and the load and the corresponding relationship between the displacement and the load;

[0173] S63: If the correlation coefficient is greater than a preset threshold, the initial corresponding relationship between the displacement and the load is used as the corresponding relationship between the displacement and the load.

[0174] It should be noted that the initial corresponding relationship may be a corresponding relationship directly determined based on a curve fitting performed according to the displacement and load data of the suspension bushing.

[0175] The correlation coefficient may be an indicator used in statistics to measure the strength of the linear relationship between two variables. In the embodiment of the present application, the correlation coefficient represents the similarity between the corresponding relationship between displacement and load and the corresponding relationship between displacement and load.

[0176] In an embodiment of the present application, the initial correspondence between displacement and load can be determined based on the displacement of the suspension bushing and the load of the suspension bushing, and then the correlation coefficient can be determined based on the displacement, load, and the initial correspondence between displacement and load, wherein the correlation coefficient characterizes the degree of similarity between the displacement and load and the correspondence between the displacement and load. If the correlation coefficient is greater than a preset threshold, the initial correspondence between displacement and load is used as the correspondence between displacement and load. Among them, the method for determining the initial correspondence between displacement and load based on the displacement of the suspension bushing and the load of the suspension bushing can be curve fitting. The preset threshold can be set according to actual conditions.

[0177] In a specific implementation, the quality of the fit is judged based on the correlation coefficient. Specifically, the closer the correlation coefficient value is to 1, the higher the degree of fit between the test data and the fitting function, that is, the fitting function can better reflect the trend and change of the data. On the contrary, the closer the correlation coefficient value is to 0, the lower the degree of fit between the test data and the fitting function, and the fitting function has a weaker ability to interpret the data. In an embodiment of the present application, the preset threshold, that is, the judgment criterion, can be set to when the correlation coefficient is greater than 0.999, the fitting effect meets the requirements.

[0178] Reference Figure 2 , showing a step flow chart of a method for determining the vibration isolation rate of a vibration isolation system provided by an embodiment of the present application, wherein the vibration isolation system includes a powertrain, a frame, and a plurality of suspension bushings, wherein the powertrain and the frame are connected via the suspension bushings.

[0179] It should be noted that the vibration isolation system includes a powertrain, a vehicle frame, and several suspension bushings. Figure 3 Build a vibration isolation system, Figure 3 A schematic diagram of the structure of a vibration isolation system provided by an embodiment of the present application is shown. The specific structure of the vibration isolation system is as follows:

[0180] The vibration isolation system may include a motor assembly 3, a subframe 5 and a suspension 1, wherein the suspension includes an active side bracket 4 and a passive side bracket 2. The suspension also includes a bushing.

[0181] It should be noted that the vibration isolation system can be a system that ensures that the vibration of the powertrain (including the motor assembly) is effectively isolated and controlled. In the embodiment of the present application, the vibration isolation performance can be evaluated by calculating the vibration isolation rate of the vibration isolation system.

[0182] In electric vehicles or hybrid vehicles, the motor assembly replaces the traditional internal combustion engine and becomes the main power source of the vehicle. The motor assembly may include an electric motor, a controller, a cooling system, and other related components. Since the motor also generates vibrations during operation, it is necessary to isolate these vibrations through a vibration isolation system. In an embodiment of the present application, the connection point between the motor assembly and the suspension may be an active side connection point.

[0183] The subframe can be an auxiliary structural frame, usually made of steel or aluminum, used to support the powertrain and other vehicle components. The subframe can be connected to the main frame or body through a suspension and can serve as a vibration-isolating intermediate layer to help absorb and disperse vibrations from the powertrain. In an embodiment of the present application, the connection point between the subframe and the suspension can be a passive side connection point.

[0184] The active side bracket can be a part connected to the powertrain or motor assembly, usually a metal bracket fixed to the powertrain. In the embodiment of the present application, the active side connection point can be a bolt mounting point between the active side bracket and the motor assembly.

[0185] The passive side bracket can be a part connected to the subframe or the vehicle body, and is also a metal bracket fixed to the vehicle structure. In the embodiment of the present application, the passive side connection point is a bolt mounting point between the passive side bracket and the subframe.

[0186] The bushing may be an elastic part of the suspension, usually made of rubber or similar materials, and used to absorb and isolate vibration. In the embodiment of the present application, the vibration isolation rate may be calculated by calculating the dynamic stiffness of the bushing.

[0187] In specific implementation, the stiffness of the vibration isolation system can be calculated as follows:

[0188] The stiffness calculation formula of the vibration isolation system composed of the active side of the mount, the mount, and the passive side of the mount is:

[0189]

[0190] In the stiffness calculation formula, K is the stiffness of the vibration isolation system; K PT is the active lateral stiffness of the suspension; K M is the suspension stiffness; KB is the passive lateral stiffness of the suspension.

[0191] The method may specifically include the following steps:

[0192] S201: Under a simulation environment, when a preset unit load is applied to a suspension active side connection point and a suspension passive side connection point, respectively determine the dynamic stiffness of the suspension active side connection point and the dynamic stiffness of the suspension passive side connection point, wherein the suspension active side connection point is a connection point between the suspension bushing and the powertrain, and the suspension passive side connection point is a connection point between the suspension bushing and the vehicle frame;

[0193] S202: Determine the vibration isolation rate of the vibration isolation system according to the dynamic stiffness of the connection point on the active side of the suspension, the dynamic stiffness of the connection point on the passive side of the suspension, and the dynamic stiffness of the suspension bushing, wherein the dynamic stiffness of the suspension bushing is determined using the method for determining the dynamic stiffness of the suspension bushing as described above.

[0194] It should be noted that the dynamic stiffness of the active side connection point of the suspension may be the stiffness characteristic of the active side connection point in the suspension system under the action of a dynamic load.

[0195] The dynamic stiffness of the passive side connection point of the suspension may refer to the stiffness characteristics of the passive side connection point in the suspension system under the action of dynamic load.

[0196] It should be noted that the vibration isolation rate can indicate the degree to which the vibration isolation system reduces vibration transmission. The vibration isolation rate is usually expressed as a percentage, indicating the ratio of the amount of vibration that the vibration isolation system can reduce to the original amount of vibration. The higher the vibration isolation rate, the better the vibration isolation effect of the vibration isolation system. In the embodiment of the present application, the vibration isolation rate is used to judge the vibration isolation performance of the vibration isolation system.

[0197] In an embodiment of the present application, the dynamic stiffness of the suspension active side connection point and the dynamic stiffness of the suspension passive side connection point can be determined respectively in a simulation environment when a preset unit load is applied to the suspension active side connection point and the suspension passive side connection point, wherein the suspension active side connection point is the connection point between the suspension bushing and the powertrain, and the suspension passive side connection point is the connection point between the suspension bushing and the frame.

[0198] In the embodiment of the present application, the vibration isolation rate of the vibration isolation system can be determined based on the dynamic stiffness of the connection point on the active side of the suspension, the dynamic stiffness of the connection point on the passive side of the suspension, and the dynamic stiffness of the suspension bushing, and the dynamic stiffness of the suspension bushing is determined using the method for determining the dynamic stiffness of the suspension bushing as described above.

[0199] In a specific implementation, a motor assembly simulation finite element model and a subframe simulation finite element model can be constructed, and the suspension mounting bolt holes on the motor assembly simulation finite element model and the subframe simulation finite element model can be captured respectively, and the motor assembly side mounting holes are coupled to form the motor assembly suspension mounting main node, and the subframe side mounting holes are coupled to form the subframe suspension mounting main node. Unit loads are applied to the motor assembly suspension mounting main node and the subframe suspension mounting main node respectively, and the dynamic stiffness of the suspension active side connection point and the dynamic stiffness of the suspension passive side connection point output by the motor assembly simulation finite element model and the subframe simulation finite element model are obtained.

[0200] Among them, the finite element model can be a mathematical model used for engineering analysis and design, which discretizes complex continua (such as structures, fluids, heat conduction problems, etc.) into a limited number of simple geometric shapes, called finite elements. Each finite element is interconnected by nodes, and forces and displacements are transmitted through these nodes. In the embodiment of the present application, the finite element model can be used for finite element analysis.

[0201] In the internal logic of the motor assembly simulation finite element model and the subframe simulation finite element model, the attachment point dynamic stiffness is the origin dynamic stiffness. The origin dynamic stiffness calculation formula can be set to calculate the attachment point dynamic stiffness of the active and passive sides of the suspension. The origin dynamic stiffness calculation formula is as follows:

[0202]

[0203] In the calculation formula of the origin dynamic stiffness, m is the system mass corresponding to the dynamic stiffness, k is the system stiffness corresponding to the dynamic stiffness, c is the damping of the system corresponding to the dynamic stiffness, and ω is the excitation frequency. The excitation frequency can refer to the frequency of the external excitation force or input signal in the dynamic system.

[0204] In the specific implementation, for the suspension system, its vibration isolation rate can be theoretically expressed as

[0205]

[0206] Among them, T dB is the vibration isolation rate, K PT is the active lateral stiffness of the suspension, K M is the suspension stiffness, K B According to the above formula, after obtaining the dynamic stiffness of the active side connection point of the suspension, the dynamic stiffness of the passive side connection point of the suspension, and the dynamic stiffness of the suspension bushing, the vibration isolation rate of the suspension can be calculated.

[0207] The present application determines the dynamic stiffness of the active side connection point of the suspension and the dynamic stiffness of the passive side connection point of the suspension respectively under the condition that a preset unit load is applied to the active side connection point of the suspension and the passive side connection point of the suspension in a simulation environment, and determines the displacement of the suspension bushing and the load of the suspension bushing under the condition that a preset unit load is applied to the center of mass of the powertrain according to the nonlinear stiffness performance information of the suspension bushing in the simulation environment, determines the corresponding relationship between the displacement and the load according to the displacement of the suspension bushing and the load of the suspension bushing, and then determines the static stiffness displacement performance information according to the corresponding relationship between the displacement and the load, determines the dynamic stiffness of the suspension bushing according to the static stiffness displacement performance information and the preset corresponding relationship between dynamic and static stiffness, and determines the vibration isolation rate of the vibration isolation system according to the dynamic stiffness of the active side connection point of the suspension, the dynamic stiffness of the passive side connection point of the suspension, and the dynamic stiffness of the suspension bushing. This application can accurately simulate the working conditions of the suspension system through simulation analysis during the design phase, so as to efficiently evaluate the dynamic stiffness of the suspension and the vibration isolation rate of the vibration isolation system, avoid the situation where the suspension performance can only be verified by vehicle installation, save test time and cost, and provide strong data support for the optimal design of the suspension system.

[0208] Reference Figure 4 , showing a schematic structural diagram of a suspension bushing provided in one embodiment of the present application. Figure 4 It can be a schematic diagram of the structure of the suspension bushing on the cross section in the Y-axis direction.

[0209] The structure of the suspension bushing can be designed according to the layout space of the entire suspension vehicle and the design requirements of the suspension nonlinear stiffness curve.

[0210] It should be noted that the suspension vehicle layout space may refer to the installation and layout space reserved for the suspension system (such as engine suspension, transmission suspension, etc.) in the vehicle design.

[0211] The design requirements of the suspension nonlinear stiffness curve may refer to the specific requirements put forward for the nonlinear stiffness characteristics of the suspension bushing when designing and optimizing the suspension system.

[0212] The specific structure of the suspension bushing includes an outer liner tube 6, a linear segment 7, an active side inner liner tube 8, a rubber main spring 9, a soft limit rubber bumper 10, and a passive side bracket 2.

[0213] It should be noted that the outer liner 6 can be an external structure of the suspension system, usually made of metal material, used to fix and protect other components of the suspension system. The design of the outer liner needs to consider its strength and rigidity to ensure that it can provide stable support under various working conditions.

[0214] The linear segment 7 may refer to the range within which the stiffness of the suspension bushing is constant, ie, the load is proportional to the displacement. The linear segment performance is very important to ensure the stability and predictability of the suspension system under normal operating conditions.

[0215] The active side inner liner tube 8 can be an internal structure connected to the powertrain (such as an engine or a transmission), and is usually also made of metal materials. The design of the active side inner liner tube needs to consider its connection method and strength with the powertrain to ensure that it can effectively transfer the load and support the weight of the powertrain.

[0216] The rubber main spring 9 may be a core component of the suspension bushing, and is usually made of rubber or other elastic materials. The main function of the rubber main spring is to absorb and isolate vibration and impact from the powertrain, thereby improving the NVH performance of the vehicle. The design of the rubber main spring needs to consider its stiffness characteristics, durability and fatigue performance.

[0217] The soft limit rubber bumper 10 may be a component used to limit the displacement of the suspension bushing under extreme working conditions. When the displacement of the suspension bushing reaches a certain extent, the soft limit rubber bumper will contact the outer liner or other structures, thereby limiting further displacement. The design of the soft limit rubber bumper needs to consider its buffering performance and durability to ensure that the suspension system can be effectively protected under extreme working conditions.

[0218] These components together make up the suspension bushing, and the design and function of each component has an important impact on the overall performance of the suspension bushing. By optimizing the design and interaction of these components, the vibration isolation effect of the suspension bushing can be improved, thereby improving the NVH performance of the vehicle.

[0219] Reference Figure 5 , shows a schematic structural diagram of a device for determining the dynamic stiffness of a suspension bushing provided by an embodiment of the present application, wherein a vehicle comprises a powertrain and the suspension bushing, wherein the powertrain is connected to the suspension bushing, and the device comprises:

[0220] An information acquisition module 501 is used to acquire nonlinear stiffness performance information of the suspension bushing;

[0221] A displacement load determination module 502 is used to determine, in a simulation environment, the displacement of the suspension bushing and the load of the suspension bushing when a preset unit load is applied to the center of mass of the powertrain according to the nonlinear stiffness performance information of the suspension bushing;

[0222] A displacement-load correspondence relationship determination module 503, configured to determine a correspondence relationship between the displacement and the load according to the displacement of the suspension bushing and the load of the suspension bushing;

[0223] A static stiffness displacement performance information determination module 504, configured to determine static stiffness displacement performance information according to a corresponding relationship between the displacement and the load;

[0224] The suspension bushing dynamic stiffness determination module 505 is used to determine the suspension bushing dynamic stiffness according to the static stiffness displacement performance information and the preset static and dynamic stiffness correspondence relationship.

[0225] In an optional embodiment of the present application, the static stiffness displacement performance information determination module 404 includes:

[0226] A displacement-static-stiffness correspondence determination module, used to determine the correspondence between the displacement and the static stiffness according to the correspondence between the displacement and the load and a preset load-static-stiffness correspondence;

[0227] The static stiffness displacement performance information determination submodule is used to determine the static stiffness displacement performance information according to the corresponding relationship between the displacement and the static stiffness.

[0228] In an optional embodiment of the present application, the nonlinear stiffness performance information of the suspension bushing includes linear segment performance information, transition segment performance information, and hard limit performance information. The information acquisition module 501 includes:

[0229] A parameter coordinate acquisition module, used to acquire inertia parameters of the powertrain in a simulation environment, and to construct a whole vehicle coordinate system for the vehicle, wherein the whole vehicle coordinate system includes coordinate information of the powertrain and coordinate information of the suspension bushing;

[0230] A linear segment performance information acquisition module, used to determine the linear segment performance information of the suspension bushing according to the inertia parameters of the powertrain, the coordinate information of the powertrain and the coordinate information of the suspension bushing in a simulation environment;

[0231] A transition section performance information acquisition module, used to determine the transition section performance information of the suspension bushing according to the gear position corresponding to the vehicle;

[0232] a hard limit performance information acquisition module, configured to determine the hard limit performance information according to the displacement of the power assembly under a preset working condition of the vehicle;

[0233] A nonlinear stiffness performance information acquisition module is used to determine the nonlinear stiffness performance information of the suspension bushing according to the linear segment performance information, the transition segment performance information, and the hard limit performance information.

[0234] In an optional embodiment of the present application, the inertia parameters of the powertrain include the mass of the powertrain and the moment of inertia of the powertrain, and the linear segment performance information acquisition module includes:

[0235] A coordinate acquisition module, used for the whole vehicle coordinate system also including the center of mass coordinates of the powertrain and the elastic center coordinates of the suspension bushing;

[0236] A suspension bushing static load determination module, used to determine the static load of the suspension bushing according to the mass of the power assembly, the moment of inertia of the power assembly, the center of mass coordinates of the power assembly and the elastic center coordinates of the suspension bushing in a simulation environment;

[0237] An initial static stiffness determination module, used to determine the initial static stiffness of the suspension bushing according to the static load of the suspension bushing in a simulation environment;

[0238] The linear segment performance information acquisition submodule is used to determine the linear segment performance information of the suspension bushing according to the static load of the suspension bushing and the initial static stiffness of the suspension bushing.

[0239] In an optional embodiment of the present application, the initial static stiffness determination module includes:

[0240] A theoretical static stiffness determination module, used to determine the theoretical static stiffness of the suspension bushing according to the static load of the suspension bushing in a simulation environment;

[0241] An initial modal decoupling rate determination module, used to determine the initial mode of the suspension bushing and the initial decoupling rate of the suspension bushing according to the theoretical static stiffness of the suspension bushing in a simulation environment;

[0242] The initial static stiffness optimization module is used to adjust the theoretical static stiffness of the suspension bushing according to the initial mode of the suspension bushing and the initial decoupling rate of the suspension bushing to obtain the initial static stiffness of the suspension bushing.

[0243] In an optional embodiment of the present application, the device further includes:

[0244] a target modal decoupling rate determination module, which determines the target mode of the suspension bushing and the target decoupling rate of the suspension bushing according to the dynamic stiffness of the suspension bushing in a simulation environment;

[0245] A modality change determination module, used to determine a modality change according to the initial modality and the target modality;

[0246] A decoupling rate change determination module, used to determine a decoupling rate change according to the initial decoupling rate and the target decoupling rate;

[0247] The modal decoupling rate verification result determination module is used to determine the modal decoupling rate verification result of the suspension bushing according to the modal change and the decoupling rate change.

[0248] In an optional embodiment of the present application, the displacement-load correspondence determination module 503 includes:

[0249] An initial corresponding relationship determining module, used to determine an initial corresponding relationship between the displacement and the load according to the displacement of the suspension bushing and the load of the suspension bushing;

[0250] a correlation coefficient determination module, configured to determine a correlation coefficient according to the displacement, the load, and an initial corresponding relationship between the displacement and the load, wherein the correlation coefficient represents a similarity between the displacement and the load and the corresponding relationship between the displacement and the load;

[0251] The displacement-load correspondence determination submodule is used to take the initial correspondence between the displacement and the load as the correspondence between the displacement and the load if the correlation coefficient is greater than a preset threshold.

[0252] Reference Figure 6 , shows a schematic structural diagram of a device for determining a vibration isolation rate of a vibration isolation system provided by an embodiment of the present application, wherein the vibration isolation system comprises a powertrain, a vehicle frame, and a plurality of suspension bushings, wherein the powertrain and the vehicle frame are connected via the suspension bushings, and the device comprises:

[0253] The connection point dynamic stiffness determination module 601 is used to determine the dynamic stiffness of the connection point on the active side of the suspension and the dynamic stiffness of the connection point on the passive side of the suspension respectively under the condition that a preset unit load is applied to the connection point on the active side of the suspension and the connection point on the passive side of the suspension in a simulation environment, wherein the connection point on the active side of the suspension is the connection point between the suspension bushing and the powertrain, and the connection point on the passive side of the suspension is the connection point between the suspension bushing and the vehicle frame;

[0254] The vibration isolation rate determination module 602 is used to determine the vibration isolation rate of the vibration isolation system according to the dynamic stiffness of the connection point of the active side of the suspension, the dynamic stiffness of the connection point of the passive side of the suspension, and the dynamic stiffness of the suspension bushing, wherein the dynamic stiffness of the suspension bushing is determined using the method for determining the dynamic stiffness of the suspension bushing as described above.

[0255] As for the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0256] An embodiment of the present application also provides an electronic device, which may include a processor, a memory, and a computer program stored in the memory and capable of running on the processor. When the computer program is executed by the processor, it implements the method for determining the dynamic stiffness of the suspension bushing as described above or the method for determining the vibration isolation rate of the vibration isolation system as described above.

[0257] An embodiment of the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the method for determining the dynamic stiffness of the suspension bushing as described above or the method for determining the vibration isolation rate of the vibration isolation system as described above is implemented.

[0258] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with the relevant laws, regulations and standards of the relevant countries and regions, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0259] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0260] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, devices, or computer program products. Therefore, the embodiments of the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment 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, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0261] The embodiments of the present application are described with reference to the flowcharts and / or block diagrams of the methods, terminal 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 terminal device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing terminal 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.

[0262] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing terminal device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product 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.

[0263] These computer program instructions can also be loaded onto a computer or other programmable data processing terminal device so that a series of operating steps are executed on the computer or other programmable terminal device to produce a computer-implemented process, thereby providing instructions for executing on the computer or other programmable terminal device to implement the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0264] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the embodiments of the present application.

[0265] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or terminal device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or terminal device. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or terminal device including the above elements.

[0266] The above provides a detailed introduction to the method and device for determining the dynamic stiffness of a suspension bushing and the vibration isolation rate of a vibration isolation system. This article uses specific examples to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for general technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A method for determining the dynamic stiffness of a suspension bushing, characterized in that: The vehicle comprises a powertrain and the suspension bushing, the powertrain being connected to the suspension bushing, and the method comprising: Acquiring nonlinear stiffness performance information of the suspension bushing; In a simulation environment, determining, based on nonlinear stiffness performance information of the suspension bushing, a displacement of the suspension bushing and a load of the suspension bushing when a preset unit load is applied to the center of mass of the powertrain; Determining a corresponding relationship between the displacement and the load according to the displacement of the suspension bushing and the load of the suspension bushing; Determining static stiffness displacement performance information according to the corresponding relationship between the displacement and the load; The dynamic stiffness of the suspension bushing is determined according to the static stiffness displacement performance information and the preset static and dynamic stiffness correspondence.

2. The method according to claim 1, characterized in that Determining static stiffness displacement performance information according to the corresponding relationship between the displacement and the load includes: Determining the corresponding relationship between the displacement and the static stiffness according to the corresponding relationship between the displacement and the load and a preset corresponding relationship between the load and the static stiffness; The static stiffness displacement performance information is determined according to the corresponding relationship between the displacement and the static stiffness.

3. The method according to claim 1, characterized in that The nonlinear stiffness performance information of the suspension bushing includes linear segment performance information, transition segment performance information, and hard limit performance information. The step of obtaining the nonlinear stiffness performance information of the suspension bushing includes: In a simulation environment, obtaining inertia parameters of the powertrain, and constructing a whole vehicle coordinate system for the vehicle, wherein the whole vehicle coordinate system includes coordinate information of the powertrain and coordinate information of the suspension bushing; In a simulation environment, determining the linear segment performance information of the suspension bushing according to the inertia parameters of the powertrain, the coordinate information of the powertrain and the coordinate information of the suspension bushing; determining the transition section performance information of the suspension bushing according to the gear position corresponding to the vehicle; determining the hard limit performance information according to the displacement of the powertrain under a preset working condition of the vehicle; The nonlinear stiffness performance information of the suspension bushing is determined according to the linear segment performance information, the transition segment performance information, and the hard limit performance information.

4. The method according to claim 3, characterized in that The inertia parameters of the powertrain include the mass of the powertrain and the moment of inertia of the powertrain. The step of determining the linear segment performance information of the suspension bushing according to the inertia parameters of the powertrain, the coordinate information of the powertrain and the coordinate information of the suspension bushing under the simulation environment includes: The vehicle coordinate system also includes the coordinates of the center of mass of the powertrain and the coordinates of the elastic center of the suspension bushing; In a simulation environment, determining a static load of the suspension bushing according to the mass of the power assembly, the moment of inertia of the power assembly, the coordinates of the center of mass of the power assembly, and the coordinates of the elastic center of the suspension bushing; In a simulation environment, determining an initial static stiffness of the suspension bushing according to a static load of the suspension bushing; The linear section performance information of the suspension bushing is determined according to the static load of the suspension bushing and the initial static stiffness of the suspension bushing.

5. The method according to claim 4, characterized in that Determining the initial static stiffness of the suspension bushing according to the static load of the suspension bushing under the simulation environment includes: In a simulation environment, determining a theoretical static stiffness of the suspension bushing according to a static load of the suspension bushing; In a simulation environment, determining an initial mode of the suspension bushing and an initial decoupling rate of the suspension bushing according to a theoretical static stiffness of the suspension bushing; The theoretical static stiffness of the suspension bushing is adjusted according to the initial mode of the suspension bushing and the initial decoupling rate of the suspension bushing to obtain the initial static stiffness of the suspension bushing.

6. The method according to claim 5, characterized in that The method further comprises: In a simulation environment, determining a target mode of the suspension bushing and a target decoupling rate of the suspension bushing according to the dynamic stiffness of the suspension bushing; Determining a modality change according to the initial modality and the target modality; Determining a decoupling rate change according to the initial decoupling rate and the target decoupling rate; The modal decoupling rate verification result of the suspension bushing is determined according to the modal change and the decoupling rate change.

7. The method according to claim 1, characterized in that Determining the corresponding relationship between the displacement and the load according to the displacement of the suspension bushing and the load of the suspension bushing includes: Determining an initial corresponding relationship between the displacement and the load according to the displacement of the suspension bushing and the load of the suspension bushing; determining a correlation coefficient according to the displacement, the load, and an initial corresponding relationship between the displacement and the load, wherein the correlation coefficient represents a similarity between the displacement and the load and the corresponding relationship between the displacement and the load; If the correlation coefficient is greater than a preset threshold, the initial corresponding relationship between the displacement and the load is used as the corresponding relationship between the displacement and the load.

8. A method for determining the vibration isolation rate of a vibration isolation system, characterized in that: The vibration isolation system includes a powertrain, a vehicle frame, and a plurality of suspension bushings, wherein the powertrain and the vehicle frame are connected via the suspension bushings, and the method includes: In a simulation environment, when a preset unit load is applied to a suspension active side connection point and a suspension passive side connection point, the dynamic stiffness of the suspension active side connection point and the dynamic stiffness of the suspension passive side connection point are determined respectively, wherein the suspension active side connection point is a connection point between the suspension bushing and the powertrain, and the suspension passive side connection point is a connection point between the suspension bushing and the vehicle frame; The vibration isolation rate of the vibration isolation system is determined according to the dynamic stiffness of the connection point on the active side of the suspension, the dynamic stiffness of the connection point on the passive side of the suspension, and the dynamic stiffness of the suspension bushing, wherein the dynamic stiffness of the suspension bushing is determined by the method for determining the dynamic stiffness of the suspension bushing described in claim 1.

9. A device for determining the dynamic stiffness of a suspension bushing, characterized in that: The vehicle comprises a powertrain and the suspension bushing, the powertrain is connected to the suspension bushing, and the device comprises: An information acquisition module, used to acquire nonlinear stiffness performance information of the suspension bushing; a displacement load determination module, for determining, in a simulation environment, the displacement of the suspension bushing and the load of the suspension bushing when a preset unit load is applied to the center of mass of the powertrain according to the nonlinear stiffness performance information of the suspension bushing; A displacement-load correspondence determination module, used to determine the correspondence between the displacement and the load according to the displacement of the suspension bushing and the load of the suspension bushing; A static stiffness displacement performance information determination module, used to determine the static stiffness displacement performance information according to the corresponding relationship between the displacement and the load; The suspension bushing dynamic stiffness determination module is used to determine the suspension bushing dynamic stiffness according to the static stiffness displacement performance information and the preset static and dynamic stiffness correspondence relationship.

10. A device for determining the vibration isolation rate of a vibration isolation system, characterized in that: The vibration isolation system includes a powertrain, a vehicle frame, and a plurality of suspension bushings. The powertrain and the vehicle frame are connected via the suspension bushings. The device includes: A connection point dynamic stiffness determination module, used for determining the dynamic stiffness of the connection point on the active side of the suspension and the dynamic stiffness of the connection point on the passive side of the suspension respectively under a simulation environment, when a preset unit load is applied to the connection point on the active side of the suspension and the connection point on the passive side of the suspension, wherein the connection point on the active side of the suspension is the connection point between the suspension bushing and the powertrain, and the connection point on the passive side of the suspension is the connection point between the suspension bushing and the vehicle frame; A vibration isolation rate determination module is used to determine the vibration isolation rate of the vibration isolation system according to the dynamic stiffness of the connection point on the active side of the suspension, the dynamic stiffness of the connection point on the passive side of the suspension, and the dynamic stiffness of the suspension bushing, wherein the dynamic stiffness of the suspension bushing is determined by the method for determining the dynamic stiffness of the suspension bushing described in claim 1.

11. An electronic device, characterized in that: The method comprises a processor, a memory and a computer program stored in the memory and capable of running on the processor, wherein the computer program, when executed by the processor, implements a method for determining the dynamic stiffness of a suspension bushing as described in any one of claims 1 to 8 or a method for determining the vibration isolation rate of a vibration isolation system as described in claim 9.

12. 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 method for determining the dynamic stiffness of the suspension bushing according to any one of claims 1 to 8 or the method for determining the vibration isolation rate of the vibration isolation system according to claim 9 is implemented.

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