Vehicle door tremor sound prediction and optimization method and system

Abstract

The invention relates to a vehicle door tremor sound prediction and optimization method and system. The method comprises the following steps: establishing a finite element model after a glass lifter motor assembly, a glass guide rail and a vehicle door metal plate assembly are assembled; performing rigidity analysis and modal analysis on the finite element model to obtain a displacement value of a loading point and a local constraint modal value corresponding to the mounting position of the window glass lifter motor assembly; judging whether the local constraint modal value is greater than or equal to a modal threshold value and whether the displacement value of the loading point is less than or equal to a displacement threshold value; if the local constraint modal value is greater than or equal to the modal threshold value and the displacement value of the loading point is less than or equal to the displacement threshold value, determining that there is no risk of abnormal vibration sound; otherwise, the risk of abnormal tremor sound exists, joint judgment is conducted on the local constraint mode value obtained through the rigidity working condition and the mode working condition and the displacement value of the loading point, the tremor sound caused by the window glass lifter motor can be predicted in advance, and the problem that the tremor sound problem lags to be found in a traditional design process is solved.

Description

Technical Field

[0001] The present application relates to the field of vehicle vibration and noise control, and in particular to a method and system for predicting and optimizing vehicle door chatter. Background Art

[0002] The door mode of a passenger car is an important indicator in the vehicle modal matching table. It should be reasonably matched and designed for both the body-in-white (BIW) and the entire vehicle. If the modal frequency is too low, it is easy to be excited by the road surface and cause door vibration.

[0003] In addition, after the window lift motor is installed in the car door, there is a risk of vibration caused by the window lift motor stimulating the car door. Generally, the design is optimized after the vibration is discovered during the actual vehicle test. This passive verification mode affects the time and resource investment in the prototype vehicle production stage.

[0004] Therefore, how to accurately determine whether the window lift motor will cause vibration noise in the early design stage of vehicle development, avoid the risk of this problem occurring in the actual vehicle later, speed up the project development cycle, and improve the quality of the entire vehicle, is an urgent problem that needs to be solved. Summary of the Invention

[0005] The embodiments of the present application provide a method and system for predicting and optimizing vehicle door vibration to solve the problem in related technologies that optimization design is performed after vibration is discovered during actual vehicle testing. This passive verification mode affects the time and resource investment in the prototype vehicle production stage.

[0006] In a first aspect, a method for predicting door chatter is provided, comprising:

[0007] Establish a finite element model of the assembled window lift motor assembly, glass guide rails, and door sheet metal assembly;

[0008] Performing stiffness analysis and modal analysis on the finite element model to obtain displacement values ​​of the loading point and local constraint modal values ​​corresponding to the installation position of the window lifter motor assembly;

[0009] Determine whether the local constraint modal value is greater than or equal to the modal threshold, and whether the displacement value of the loading point is less than or equal to the displacement threshold;

[0010] If the local constraint modal value is greater than or equal to the modal threshold, and the displacement value of the loading point is less than or equal to the displacement threshold, there is no risk of abnormal vibration or noise; otherwise, there is a risk of abnormal vibration or noise.

[0011] In some embodiments, performing stiffness analysis on the finite element model to obtain the displacement value of the loading point specifically includes the following steps:

[0012] The middle position of the motor suspension end of the window lifter motor assembly in the finite element model is used as the loading position;

[0013] After constraining the finite element model according to the actual vehicle state, a design loading force in the Y direction is applied to the loading position, and then a stiffness analysis is performed to obtain the displacement value of the loading point.

[0014] In some embodiments, performing modal analysis on the finite element model to obtain local constraint modal values ​​corresponding to the installation position of the window lift motor assembly specifically includes the following steps:

[0015] After constraining the finite element model according to the actual vehicle state, performing modal analysis on the finite element model to obtain a modal vibration shape cloud diagram;

[0016] The modal vibration shape cloud diagram is identified to obtain the local constraint modal value corresponding to the installation position of the window lift motor assembly.

[0017] In some embodiments, constraining the finite element model according to the actual vehicle state specifically includes the following steps:

[0018] Fully restrain the hinges of the door sheet metal assembly;

[0019] Constrain the Y and Z translational degrees of freedom, as well as the rotational degrees of freedom around the X and Y axes, at the door lock of the door sheet metal assembly.

[0020] In some embodiments, the door sheet metal assembly is meshed using shell elements; the window lifter motor assembly is meshed using solid elements; the glass guide rail is meshed using shell elements; the bolted connection between the window lifter motor assembly and the door sheet metal assembly is simulated using rigid elements, and the welds of the door sheet metal assembly are simulated using acm elements.

[0021] In a second aspect, a method for optimizing vehicle door chatter noise is provided, comprising:

[0022] When the door chatter prediction method predicts the risk of abnormal rattle, stiffness analysis and modal analysis are performed on the finite element model to obtain modal vibration shape cloud diagrams and displacement distribution cloud diagrams.

[0023] Extracting a first target area corresponding to the installation position of the window lifter motor assembly from the displacement distribution cloud map, and extracting a second target area corresponding to the installation position of the window lifter motor assembly from the modal vibration shape cloud map;

[0024] The optimization is performed based on the first target area and the second target area.

[0025] In some embodiments, the optimization based on the first target area and the second target area specifically includes the following steps:

[0026] Analyze whether there is an area with excessive displacement in the first target area according to the displacement threshold;

[0027] Analyze whether there is a low-frequency vibration concentration area in the second target area according to the modal threshold;

[0028] If only the area with excessive displacement exists, radial reinforcement ribs are added to the back of the motor mounting bracket of the window lifter motor assembly corresponding to the area with excessive displacement, or the thickness of the motor mounting bracket of the window lifter motor assembly corresponding to the area with excessive displacement is increased;

[0029] If only low-frequency vibration concentration areas exist, change the spacing and number of bolts corresponding to the low-frequency vibration concentration areas; the bolts are used to connect the window lifter motor assembly to the door sheet metal assembly;

[0030] If both low-frequency vibration concentration areas and displacement exceeding the standard areas exist, radial reinforcement ribs shall be added to the back of the motor mounting bracket of the window lifter motor assembly corresponding to the displacement exceeding the standard area, or the thickness of the motor mounting bracket of the window lifter motor assembly corresponding to the displacement exceeding the standard area shall be increased; the spacing and number of bolts corresponding to the low-frequency vibration concentration area shall be changed.

[0031] In some embodiments, when there is a low-frequency vibration concentration area, the optimization method further includes adding a concentric annular flange to the periphery of the bolt hole corresponding to the bolt.

[0032] In a third aspect, a door chatter prediction system is provided, comprising:

[0033] The first module is used to establish a finite element model of the assembled window lift motor assembly, glass guide rails, and door sheet metal assembly;

[0034] A second module is used to perform stiffness analysis and modal analysis on the finite element model to obtain a displacement value of a loading point and a local constraint modal value corresponding to an installation position of a window lifter motor assembly;

[0035] The third module is used to determine whether the local constraint modal value is greater than or equal to the modal threshold, and whether the displacement value of the loading point is less than or equal to the displacement threshold; if the local constraint modal value is greater than or equal to the modal threshold, and the displacement value of the loading point is less than or equal to the displacement threshold, there is no risk of abnormal vibration; otherwise, there is a risk of abnormal vibration.

[0036] In a fourth aspect, a vehicle door chatter noise optimization system is provided, comprising:

[0037] The fourth module is used to perform stiffness analysis and modal analysis on the finite element model to obtain a modal shape cloud map and a displacement distribution cloud map when the door chatter prediction system predicts the risk of abnormal rattle.

[0038] A fifth module is configured to extract a first target region corresponding to the installation position of the window lifter motor assembly from the displacement distribution cloud map, and to extract a second target region corresponding to the installation position of the window lifter motor assembly from the modal vibration shape cloud map;

[0039] The sixth module is configured to perform optimization based on the first target area and the second target area.

[0040] The beneficial effects of the technical solution provided by this application include:

[0041] An embodiment of the present application provides a method and system for predicting and optimizing vehicle door chatter noise, which establishes a finite element model of the assembled glass lifter motor assembly, glass guide rail and door sheet metal assembly; performs stiffness analysis and modal analysis on the finite element model to obtain the displacement value of the loading point and the local constraint modal value corresponding to the installation position of the glass lifter motor assembly; determines whether the local constraint modal value is greater than or equal to the modal threshold, and whether the displacement value of the loading point is less than or equal to the displacement threshold; if the local constraint modal value is greater than or equal to the modal threshold, and the displacement value of the loading point is less than or equal to the displacement threshold, then there is no risk of abnormal chatter noise; otherwise, there is a risk of abnormal chatter noise. The local constraint modal value and the displacement value of the loading point obtained from the two working conditions of stiffness and modality in the above method are jointly judged, which can predict the chatter noise caused by the glass lifter motor in advance, solving the problem of delayed discovery of chatter noise problems in traditional design processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0043] Figure 1 A schematic diagram of the general flow of the door chatter prediction method provided in an embodiment of the present application;

[0044] Figure 2 A schematic diagram of the general flow of the door chatter noise optimization method provided in an embodiment of the present application;

[0045] Figure 3 A schematic diagram of a finite element model of the assembled window lifter motor assembly, glass guide rail, and door sheet metal assembly provided in an embodiment of the present application;

[0046] Figure 4 Schematic diagram of the state where the designed loading force in the Y direction is applied to the loading position provided in an embodiment of the present application. DETAILED DESCRIPTION

[0047] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0048] Constrained modes are the global vibration characteristics of a structure after applying practical boundary conditions (such as fully constrained hinges or partially constrained door locks). Their modal frequencies and mode shapes describe the vibration patterns of the entire structure under the constraints. Each mode corresponds to a specific vibration pattern (such as global bending, torsion, or localized vibration) and is not attributed to a specific mounting point.

[0049] The embodiments of the present application provide a method and system for predicting and optimizing vehicle door vibration noise to solve the problem in related technologies of performing optimization design after vibration noise is discovered during actual vehicle testing. This passive verification mode affects the time and resource investment in the prototype vehicle production stage, mainly targeting the situation where vibration noise is generated after the window lifter motor assembly is installed.

[0050] In a first aspect, a door chatter prediction method is proposed, which includes:

[0051] Step 100: Establish a finite element model of the assembled window lifter motor assembly, glass guide rail, and door sheet metal assembly;

[0052] Step 200: Perform stiffness analysis and modal analysis on the finite element model to obtain displacement values ​​of the loading point and local constraint modal values ​​corresponding to the installation position of the window lifter motor assembly.

[0053] Step 300: Determine whether the local constraint modal value is greater than or equal to the modal threshold, and whether the displacement value of the loading point is less than or equal to the displacement threshold;

[0054] Step 400: If the local constraint modal value is greater than or equal to the modal threshold, and the displacement value of the loading point is less than or equal to the displacement threshold, there is no risk of abnormal vibration or sound; otherwise, there is a risk of abnormal vibration or sound.

[0055] The combined judgment of the displacement values ​​of the loading points of the local constrained modal values ​​obtained from the stiffness and modal working conditions described above can make early predictions about the vibration noise caused by the window lifter motor, solving the problem of delayed discovery of the vibration noise problem in the traditional design process.

[0056] It is possible to predict the risk of vibration noise after motor installation through simulation during the door design stage, replacing the traditional passive verification mode that relies on actual vehicle testing, and forming a development closed loop of "simulation-driven optimization-actual vehicle noise avoidance".

[0057] In some preferred embodiments, the door sheet metal assembly is meshed using shell elements; the glass lifter motor assembly is meshed using solid elements; the glass guide rail is meshed using shell elements; the bolt connection between the glass lifter motor assembly and the door sheet metal assembly is simulated using rigid elements, and the welds of the door sheet metal assembly are simulated using acm elements.

[0058] Among them, the door sheet metal assembly is divided into 10×10mm shell unit grids; the window lifter motor assembly includes the motor and cover plate. Because it has many features and is a key influencing factor, it is divided into 2×2mm solid units, and the glass guide rail is divided into 2×2mm shell units.

[0059] The above realizes the differentiated meshing strategy and multi-component coupling modeling, making the subsequent analysis results accurate.

[0060] In some preferred embodiments, in step 200:

[0061] Perform stiffness analysis on the finite element model to obtain the displacement value of the loading point, which specifically includes the following steps:

[0062] The middle position of the motor suspension end of the window lifter motor assembly in the finite element model is used as the loading position;

[0063] After constraining the finite element model according to the actual vehicle state, a design load force in the Y direction is applied at the loading position, and then a stiffness analysis is performed to obtain the displacement value of the loading point. The displacement threshold is 7mm. The design load force is 100N.

[0064] Performing modal analysis on the finite element model to obtain the local constraint modal values ​​corresponding to the installation position of the window lift motor assembly includes the following steps:

[0065] After constraining the finite element model according to the actual vehicle state, perform modal analysis on the finite element model to obtain the modal vibration shape cloud diagram;

[0066] The modal shape cloud map is used to identify the local constrained modal values ​​corresponding to the installation location of the window lift motor assembly, with a modal threshold of 29Hz. The local constrained modal values ​​are obtained through modal shape screening, that is, by observing the modal shape cloud map, the modes with significant vibration amplitudes at the motor installation location (such as local sheet metal vibration, bracket bending, etc.) are identified.

[0067] Furthermore, the finite element model is constrained according to the actual vehicle state, which specifically includes the following steps:

[0068] Fully restrain the hinges of the door sheet metal assembly;

[0069] Constrain the Y and Z translational degrees of freedom at the door lock of the door sheet metal assembly, as well as the rotational degrees of freedom around the X and Y axes. The X, Y, and Z axes represent the vehicle's longitudinal direction, the Y axis represents the vehicle's lateral direction (positive direction points to the right and negative direction points to the left), and the Z axis represents the vehicle's vertical direction.

[0070] This embodiment introduces a general process of obtaining the displacement value of the loading point of the local constraint modal value, that is, performing local modal analysis and stiffness analysis of the motor installation position.

[0071] The reasons for designing the above displacement threshold of 7mm and modal threshold of 29Hz are:

[0072] The frequency of these modes must be ≥29Hz to avoid resonance with the engine, road bumps, etc., and high modal frequencies correspond to more rigid structures, improving overall safety and durability.

[0073] According to the comparison between multi-model and multi-scheme simulation and actual test, when the simulation working conditions 1 and 2 are met at the same time, no vibration or abnormal noise occurs after the window lifter motor is installed on the actual vehicle.

[0074] In a second aspect, a method for optimizing door chatter noise is proposed, which includes the following steps:

[0075] Step 500: When the above vehicle door chatter noise prediction method predicts the presence of a risk of abnormal door chatter noise, stiffness analysis and modal analysis are performed on the finite element model to obtain a modal vibration shape cloud diagram and a displacement distribution cloud diagram;

[0076] Step 600: Extract the first target area corresponding to the installation position of the window lifter motor assembly from the displacement distribution cloud map, and extract the second target area corresponding to the installation position of the window lifter motor assembly from the modal vibration shape cloud map;

[0077] Step 700: Optimize based on the first target area and the second target area.

[0078] Step 800: After optimization, perform door chatter prediction again until the risk of abnormal door chatter is eliminated.

[0079] The above step 700 specifically includes the following steps:

[0080] Analyze whether there is an area with excessive displacement in the first target area according to the displacement threshold;

[0081] Analyze whether there is a low-frequency vibration concentration area in the second target area according to the modal threshold;

[0082] If only the area with excessive displacement exists, radial reinforcement ribs are added to the back of the motor mounting bracket of the window lifter motor assembly corresponding to the area with excessive displacement, or the thickness of the motor mounting bracket of the window lifter motor assembly corresponding to the area with excessive displacement is increased;

[0083] If only low-frequency vibration concentration areas exist, change the spacing and number of bolts corresponding to the low-frequency vibration concentration areas; the bolts are used to connect the window lifter motor assembly to the door sheet metal assembly;

[0084] If both low-frequency vibration concentration areas and displacement exceeding the standard areas exist, radial reinforcement ribs shall be added to the back of the motor mounting bracket of the window lifter motor assembly corresponding to the displacement exceeding the standard area, or the thickness of the motor mounting bracket of the window lifter motor assembly corresponding to the displacement exceeding the standard area shall be increased; the spacing and number of bolts corresponding to the low-frequency vibration concentration area shall be changed.

[0085] Among them, when there is a low-frequency vibration concentration area, the optimization method also includes adding a concentric annular flange to the periphery of the bolt hole corresponding to the bolt.

[0086] It should be understood that:

[0087] Rigidity is enhanced by adding radial reinforcement ribs to the back of the motor mounting bracket to increase local stiffness. The ribs align with the principal stress direction, which is determined by stiffness analysis, to avoid stress concentration.

[0088] Modal enhancement involves distributed reinforcement of mounting points, such as replacing a single-row bolt connection with a double-row staggered bolt layout to increase the number of restraint points. Alternatively, an annular flange can be added around the bolt hole to improve the hole's resistance to deformation. This embodiment only provides one optimized implementation, and other configurations are not excluded.

[0089] In a third aspect, the present application provides a door chatter prediction system, which includes:

[0090] The first module is used to establish a finite element model of the assembled window lift motor assembly, glass guide rails, and door sheet metal assembly;

[0091] The second module is used to perform stiffness analysis and modal analysis on the finite element model to obtain the displacement value of the loading point and the local constraint modal value corresponding to the installation position of the window lifter motor assembly;

[0092] The third module is used to determine whether the local constraint modal value is greater than or equal to the modal threshold, and whether the displacement value of the loading point is less than or equal to the displacement threshold; if the local constraint modal value is greater than or equal to the modal threshold, and the displacement value of the loading point is less than or equal to the displacement threshold, there is no risk of abnormal vibration; otherwise, there is a risk of abnormal vibration.

[0093] In a fourth aspect, the present application provides a vehicle door chatter noise optimization system, which includes:

[0094] The fourth module is used to perform stiffness analysis and modal analysis on the finite element model to obtain a modal shape cloud map and a displacement distribution cloud map when the door chatter prediction system predicts the risk of abnormal rattle.

[0095] A fifth module is configured to extract a first target region corresponding to the installation position of the window lifter motor assembly from the displacement distribution cloud map, and to extract a second target region corresponding to the installation position of the window lifter motor assembly from the modal vibration shape cloud map;

[0096] The sixth module is configured to perform optimization based on the first target area and the second target area.

[0097] Among them, the functional implementation of each module mentioned above corresponds to the various steps in the above-mentioned embodiment of the door vibration prediction and optimization method, and its functions and implementation processes will not be repeated here one by one.

[0098] In a fifth aspect, an embodiment of the present application provides a vehicle door chatter prediction device, which may be a personal computer (PC), a laptop computer, a server, or other device with data processing capabilities.

[0099] A door chatter prediction device may include a processor, memory, a communication interface, and a communication bus. The communication bus can be of any type and is used to interconnect the processor, memory, and communication interface. Communication interfaces include input / output (I / O) interfaces, physical interfaces, and logical interfaces, used to interconnect components within the door chatter prediction device, as well as interfaces used to interconnect the door chatter prediction device with other devices (e.g., other computing devices or user devices). Physical interfaces may include Ethernet interfaces, fiber optic interfaces, ATM interfaces, etc.; user devices may include displays, keyboards, etc. Memory may include various types of storage media, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), flash memory, optical storage, hard disks, programmable ROM (PROM), erasable PROM (EPROM), and electrically erasable PROM (EEPROM). The processor may be a general-purpose processor that can invoke a door chatter prediction program stored in a memory and execute the door chatter prediction method provided in the embodiments of the present application. For example, the general-purpose processor may be a central processing unit (CPU). The method executed when the door chatter prediction program is invoked can be referenced from the various embodiments of the door chatter prediction method of the present application and will not be further described here.

[0100] In a sixth aspect, an embodiment of the present application also provides a computer-readable storage medium.

[0101] The computer-readable storage medium of the present application stores a vehicle door chatter prediction program. When executed by a processor, the vehicle door chatter prediction program implements the steps of the vehicle door chatter prediction method described above. The methods implemented when the vehicle door chatter prediction program is executed can be referenced to the various embodiments of the vehicle door chatter prediction method of the present application and will not be further described here.

[0102] In the description of this application, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0103] It should be noted that, in this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any 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 device comprising 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 device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0104] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A method for predicting door chatter, characterized in that: It includes: Establish a finite element model of the assembled window lift motor assembly, glass guide rails, and door sheet metal assembly; Performing stiffness analysis and modal analysis on the finite element model to obtain displacement values ​​of the loading point and local constraint modal values ​​corresponding to the installation position of the window lifter motor assembly; Determine whether the local constraint modal value is greater than or equal to the modal threshold, and whether the displacement value of the loading point is less than or equal to the displacement threshold; If the local constraint modal value is greater than or equal to the modal threshold, and the displacement value of the loading point is less than or equal to the displacement threshold, there is no risk of abnormal vibration or noise; otherwise, there is a risk of abnormal vibration or noise.

2. The door chatter prediction method according to claim 1, wherein: Performing stiffness analysis on the finite element model to obtain the displacement value of the loading point specifically includes the following steps: The middle position of the motor suspension end of the window lifter motor assembly in the finite element model is used as the loading position; After constraining the finite element model according to the actual vehicle state, a design loading force in the Y direction is applied to the loading position, and then a stiffness analysis is performed to obtain the displacement value of the loading point.

3. The door chatter prediction method according to claim 1, wherein: Performing modal analysis on the finite element model to obtain local constraint modal values ​​corresponding to the installation position of the window lift motor assembly specifically includes the following steps: After constraining the finite element model according to the actual vehicle state, performing modal analysis on the finite element model to obtain a modal vibration shape cloud diagram; The modal vibration shape cloud diagram is identified to obtain the local constraint modal value corresponding to the installation position of the window lift motor assembly.

4. The door chatter prediction method according to claim 2 or 3, wherein: Constraining the finite element model according to the actual vehicle state specifically includes the following steps: Fully restrain the hinges of the door sheet metal assembly; Constrain the Y and Z translational degrees of freedom, as well as the rotational degrees of freedom around the X and Y axes, at the door lock of the door sheet metal assembly.

5. The door chatter prediction method according to claim 1, wherein: The door sheet metal assembly is meshed using shell elements; the window lifter motor assembly is meshed using solid elements; the glass guide rail is meshed using shell elements; the bolt connection between the window lifter motor assembly and the door sheet metal assembly is simulated using rigid elements, and the welding points of the door sheet metal assembly are simulated using acm elements.

6. A door chatter optimization method, characterized in that: It includes the following steps: When the door chatter noise prediction method according to claim 1 predicts that there is a risk of abnormal door chatter noise, stiffness analysis and modal analysis are performed on the finite element model to obtain a modal vibration shape cloud diagram and a displacement distribution cloud diagram; Extracting a first target area corresponding to the installation position of the window lifter motor assembly from the displacement distribution cloud map, and extracting a second target area corresponding to the installation position of the window lifter motor assembly from the modal vibration shape cloud map; The optimization is performed based on the first target area and the second target area.

7. The door chatter optimization method according to claim 6, wherein: Optimization based on the first target area and the second target area specifically includes the following steps: Analyze whether there is an area with excessive displacement in the first target area according to the displacement threshold; Analyze whether there is a low-frequency vibration concentration area in the second target area according to the modal threshold; If only the area with excessive displacement exists, radial reinforcement ribs are added to the back of the motor mounting bracket of the window lifter motor assembly corresponding to the area with excessive displacement, or the thickness of the motor mounting bracket of the window lifter motor assembly corresponding to the area with excessive displacement is increased; If only low-frequency vibration concentration areas exist, change the spacing and number of bolts corresponding to the low-frequency vibration concentration areas; the bolts are used to connect the window lifter motor assembly to the door sheet metal assembly; If both low-frequency vibration concentration areas and displacement exceeding the standard areas exist, radial reinforcement ribs shall be added to the back of the motor mounting bracket of the window lifter motor assembly corresponding to the displacement exceeding the standard area, or the thickness of the motor mounting bracket of the window lifter motor assembly corresponding to the displacement exceeding the standard area shall be increased; the spacing and number of bolts corresponding to the low-frequency vibration concentration area shall be changed.

8. The door chatter optimization method according to claim 7, wherein: When there is a low-frequency vibration concentration area, the optimization method also includes adding a concentric annular flange to the periphery of the bolt hole corresponding to the bolt.

9. A door chatter prediction system, characterized in that: It includes: The first module is used to establish a finite element model of the assembled window lift motor assembly, glass guide rails, and door sheet metal assembly; A second module is used to perform stiffness analysis and modal analysis on the finite element model to obtain a displacement value of a loading point and a local constraint modal value corresponding to an installation position of a window lifter motor assembly; The third module is used to determine whether the local constraint modal value is greater than or equal to the modal threshold, and whether the displacement value of the loading point is less than or equal to the displacement threshold; if the local constraint modal value is greater than or equal to the modal threshold, and the displacement value of the loading point is less than or equal to the displacement threshold, there is no risk of abnormal vibration; otherwise, there is a risk of abnormal vibration.

10. A door chatter optimization system, characterized in that: It includes: The fourth module is used to perform stiffness analysis and modal analysis on the finite element model to obtain a modal shape cloud map and a displacement distribution cloud map when the door chatter prediction system predicts the risk of abnormal rattle. A fifth module is configured to extract a first target region corresponding to the installation position of the window lifter motor assembly from the displacement distribution cloud map, and to extract a second target region corresponding to the installation position of the window lifter motor assembly from the modal vibration shape cloud map; The sixth module is configured to perform optimization based on the first target area and the second target area.

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