An adaptive anti-resonance suspension system and method based on road vibration

Abstract

The application discloses a kind of adaptive frequency avoidance suspension systems and methods based on road vibration comprising suspension modal frequency acquisition module, road vibration frequency acquisition module, frequency decoupling judging module and suspension mass distribution adjustment module. The road vibration frequency is obtained by measuring the velocity of wheel center in each direction in real time, and the modal frequencies of the current suspension are analyzed, to determine whether the two are decoupled. According to the results of the judgment, the mass distribution of the suspension is adjusted, so that the modal frequencies of the suspension are adjusted, and the modal frequencies of the suspension and the road vibration frequency are always decoupled. Frequency decoupling is achieved in all road sections and all scenarios of the vehicle, ensuring that the road noise of the vehicle is always at a low level. The adaptive frequency avoidance suspension system designed by the application has a simple structure, the operation of adjusting the mass distribution of the suspension is simple, and the cost of modifying the production and assembly of the suspension is low.

Description

Technical Field

[0001] This invention relates to the field of vehicle noise reduction technology, specifically to an adaptive frequency avoidance suspension system and method based on road vibration. Background Technology

[0002] Due to factors such as road surface roughness, vehicle wheels vibrate when rolling on the road. If the modal frequencies of the vehicle's suspension system overlap and couple with the road vibration frequencies, the suspension system will amplify the vibrations, resulting in significant vibration noise in the cabin. The modal frequencies of the vehicle's suspension system are inherent properties of the structure, determined by factors such as the structure's stiffness, stiffness distribution, mass, and mass distribution. Road vibration frequencies are related to tire material, structure, tire pressure, and road surface roughness. Typical road vibration frequencies range from 20 to 200 Hz (they may exceed this range in special cases, such as underinflated tires, worn tires, or complex road surfaces). The vehicle's suspension system consists of elastic elements, guiding mechanisms, and damping elements. Under different vehicle loads, the suspension system undergoes significant deformation, resulting in different structures and thus different modal frequencies under different loads.

[0003] The common method for suppressing road noise during vehicle development is to design the suspension system so that its modal frequency under design load reaches 200Hz or higher to avoid overlapping and coupling between the suspension system and the road vibration frequency, thereby preventing the suspension system from amplifying road vibration and generating significant road noise.

[0004] However, the aforementioned techniques cannot accurately identify the vehicle's road vibration frequency. They rely solely on empirical values ​​of road vibration frequency for suspension decoupling design. In special circumstances, the road vibration frequency may exceed these empirical values, leading to resonance with the suspension system. Currently, vehicle suspensions are designed and developed for frequency avoidance under the vehicle's design loads, without considering suspension deformation under different loads and the modal frequencies after deformation. This makes it impossible to guarantee that the modal frequencies of the deformed suspension can still be decoupled from the road vibration frequency. Therefore, current road noise suppression methods have significant limitations and cannot suppress road noise across all vehicle usage scenarios. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the aforementioned background technology and provide an adaptive frequency avoidance suspension system and method that can suppress vehicle road noise in all scenarios based on road vibration.

[0006] To achieve this objective, the adaptive frequency avoidance suspension system based on road vibration designed in this invention includes a suspension modal frequency acquisition module, a road vibration frequency acquisition module, a frequency decoupling judgment module, and a suspension mass distribution adjustment module. The suspension modal frequency acquisition module is used to construct a suspension state model based on suspension load, suspension deformation, and suspension mass distribution, and analyze to obtain the various modal frequencies F1 of the suspension. The road vibration frequency acquisition module is used to convert the velocity signals at the wheel center into road vibration frequency signals, outputting several road vibration frequencies F2 with the highest amplitude. The frequency decoupling judgment module is used to compare the various modal frequencies F1 of the suspension with the several road vibration frequencies F2 with the highest amplitude, determine whether F1 and F2 are coupled, and output the coupling judgment result. The suspension mass distribution adjustment module is used to adjust or maintain the mass distribution of the suspension according to the coupling judgment result, so that the various modal frequencies F1 of the suspension remain decoupled from the several road vibration frequencies F2 with the highest amplitude.

[0007] Furthermore, the suspension modal frequency acquisition module includes a vehicle load and suspension deformation analysis module and a suspension modal frequency analysis module. The vehicle load and suspension deformation analysis module is used to construct a suspension model and receive suspension load signals, analyze the deformation of suspension components based on the suspension load signals and suspension model, and output the deformation information R of the suspension components. The suspension modal frequency analysis module is used to construct the current suspension state model based on the deformation information R of the suspension components and the suspension mass distribution information M, and analyze and output the modal frequencies F1 of the current suspension.

[0008] Furthermore, the suspension mass distribution adjustment module includes multiple liquid bladders fixed in the front and rear subframes of the suspension and a pumping device connected to the multiple liquid bladders, which can increase or decrease the mass of liquid in the multiple liquid bladders.

[0009] Furthermore, the adaptive frequency avoidance method based on the above-described adaptive frequency avoidance suspension system includes the following steps:

[0010] Step 1: Construct a suspension state model based on suspension load, suspension deformation, and suspension mass distribution, and analyze and obtain the modal frequencies F1 of the suspension.

[0011] Step 2: Convert the velocity signals at the wheel center into road vibration frequency signals, and output several road vibration frequencies F2 with the highest amplitude;

[0012] Step 3: Compare the various modal frequencies F1 of the suspension with several road vibration frequencies F2 with the highest amplitude to determine whether F1 and F2 are coupled, and output the coupling judgment result;

[0013] Step 4: Adjust or maintain the mass distribution of the suspension based on the coupling judgment results, so that the modal frequencies F1 of the suspension are decoupled from the road vibration frequencies F2 with the highest amplitude.

[0014] Furthermore, the method for obtaining the suspension deformation in step one is as follows: construct a suspension model, receive suspension load signals, and analyze the suspension load signals and suspension model to obtain the deformation information R of the suspension components.

[0015] Furthermore, the method for analyzing and obtaining the modal frequencies F1 of the suspension in step one is as follows: construct the current suspension state model based on the deformation information R of the suspension components and the suspension mass distribution information M, and analyze and obtain the modal frequencies F1 of the current suspension.

[0016] Furthermore, the method for determining whether F1 and F2 are coupled in step three is as follows: compare each modal frequency F1 of the suspension with several road vibration frequencies F2 with the highest amplitude, calculate the difference F between each modal frequency F1 of the suspension and several road vibration frequencies F2 with the highest amplitude, and if |F| is not less than the set value f, then F1 and F2 are decoupled; if |F| is less than the set value f, then F1 and F2 are coupled.

[0017] Furthermore, the method for adjusting or maintaining the suspension mass distribution based on the coupling judgment result in step four, so that the suspension modal frequencies F1 and several road vibration frequencies F2 with the highest amplitude are decoupled, is as follows: if F1 and F2 are decoupled, the current suspension mass distribution state is maintained; if F1 and F2 are coupled, the current suspension mass distribution state is adjusted until F1 and F2 are decoupled.

[0018] Furthermore, the method for adjusting the current suspension mass distribution state until F1 and F2 are decoupled is as follows: water is injected or drained into multiple fluid bladders distributed in the front and rear subframes of the suspension through a pumping device to adjust the mass of each fluid bladder and change the current suspension mass distribution state until F1 and F2 are decoupled.

[0019] Furthermore, if F is negative and |F| is less than the set value f, water is injected into the fluid bladder located in the suspension modal frequency sensitive area to increase the mass of the suspension modal frequency sensitive area and reduce the modal frequencies F1 of the suspension until F1 and F2 are decoupled; if F is positive and |F| is less than the set value f, the liquid in the fluid bladder located in the suspension modal frequency sensitive area is drained to reduce the mass of the suspension modal frequency sensitive area and increase the modal frequencies F1 of the suspension until F1 and F2 are decoupled.

[0020] The beneficial effects of this invention are as follows: By measuring the velocities of the wheel center in all directions in real time to obtain the road vibration frequency, and analyzing the modal frequencies of the current suspension, it determines whether the two are decoupled. Based on the determination result, it adjusts the mass distribution of the suspension, thereby adjusting the modal frequencies of the suspension, so that the modal frequencies of the suspension and the road vibration frequency are always decoupled. This achieves frequency decoupling for vehicles across all road sections and scenarios, ensuring that road noise is always at a low level. The adaptive frequency avoidance suspension system designed in this invention has a simple structure, simple suspension mass distribution adjustment operation, and low modification costs for suspension production and assembly. It can reduce road noise by combining data collected from multiple sensors to analyze and change the suspension mass distribution without affecting the normal function of the suspension, demonstrating good practical effects and meeting the requirements for reducing vehicle road noise in all scenarios. Attached Figure Description

[0021] Figure 1 This is a module connection diagram of the adaptive frequency avoidance suspension system designed in this invention;

[0022] Figure 2 This is a module signal transmission diagram of the adaptive frequency avoidance suspension system designed in this invention;

[0023] Figure 3 This is a schematic diagram showing the arrangement of the liquid bladder in this invention;

[0024] Among them, 1—Suspension modal frequency acquisition module (1.1—Vehicle load and suspension deformation analysis module, 1.2—Suspension modal frequency analysis module), 2—Road vibration frequency acquisition module, 3—Frequency decoupling judgment module, 4—Suspension mass distribution adjustment module, 5—Subframe, 6—Liquid bladder placement points. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0026] like Figure 1 The adaptive frequency avoidance suspension system based on road vibration shown in Figure 2 includes a suspension modal frequency acquisition module 1, a road vibration frequency acquisition module 2, a frequency decoupling judgment module 3, and a suspension mass distribution adjustment module 4.

[0027] The suspension modal frequency acquisition module 1 includes a vehicle load and suspension deformation analysis module 1.1 and a suspension modal frequency analysis module 1.2. The vehicle load and suspension deformation analysis module 1.1 is used to construct a suspension model and receive suspension load signals. Based on the suspension load signals and the suspension model, it analyzes and obtains the deformation of suspension components and outputs the deformation information R of the suspension components. The suspension modal frequency analysis module 1.2 is used to construct the current suspension state model based on the deformation information R of the suspension components and the suspension mass distribution information M, and analyzes and outputs the modal frequencies F1 of the current suspension.

[0028] The road vibration frequency acquisition module 2 is used to convert the velocity signals in all directions at the wheel center into road vibration frequency signals and output several road vibration frequencies F2 with the highest amplitude.

[0029] The frequency decoupling judgment module 3 is used to compare the various modal frequencies F1 of the suspension with several road vibration frequencies F2 with the highest amplitude, to determine whether F1 and F2 are coupled, and output the coupling judgment result.

[0030] The suspension mass distribution adjustment module 4 is used to adjust or maintain the suspension mass distribution based on the coupling judgment result, so that the various modal frequencies F1 of the suspension are decoupled from several road vibration frequencies F2 with the highest amplitude. The suspension mass distribution adjustment module 4 includes multiple fluid bladders fixed in the front and rear subframes of the suspension and a pumping device connected to the multiple fluid bladders, which can increase or decrease the fluid mass within the multiple fluid bladders. Figure 3 As shown, the subframe 5 has a hollow interior, which can be used to house liquid bladders (the subframe 5 has multiple liquid bladder placement points, which can be arranged as needed).

[0031] The adaptive frequency avoidance method based on the above adaptive frequency avoidance suspension system comprises the following steps:

[0032] Step 1: The vehicle load and suspension deformation analysis module 1.1 has a built-in suspension model. The vehicle load and suspension deformation analysis module 1.1 receives the suspension load signal (a weight sensor is set at the connection point between the vehicle suspension spring and the body or frame to receive the vehicle load signal and transmit the load information to the vehicle load and suspension deformation analysis module 1.1). Based on the suspension load signal and the suspension model, the deformation information R of the suspension components is obtained.

[0033] Step 2: The suspension modal frequency analysis module 1.2 has a modal frequency analysis model. The modal frequency analysis model constructs the current suspension state model (finite element model) based on the deformation information R of the suspension components and the suspension mass distribution information M built into the modal frequency analysis model. The modal frequencies F1 of the current suspension are then analyzed and obtained (the modal frequencies F1 of the current suspension are calculated through the finite element model).

[0034] Step 3: The road vibration frequency acquisition module 3 is set at the wheel center to acquire various velocity signals at the wheel center and convert the velocity signals at the wheel center into road vibration frequency signals, outputting several road vibration frequencies F2 with the highest amplitude (through common vibration measurement and signal processing methods in the automotive industry, the acceleration information in the time domain is transformed by FFT and converted into amplitude-frequency information, and several frequencies with the highest amplitude are selected as F2).

[0035] Step 4: The frequency decoupling judgment module 3 compares the modal frequencies F1 of the suspension with several road vibration frequencies F2 with the highest amplitude to determine whether F1 and F2 are coupled, and outputs the coupling judgment result. Specifically, it compares each modal frequency F1 of the suspension with several road vibration frequencies F2 with the highest amplitude one by one, calculates the difference F between each modal frequency F1 and several road vibration frequencies F2 with the highest amplitude. If |F| is not less than the set value f, then F1 and F2 are decoupled; if |F| is less than the set value f, then F1 and F2 are coupled.

[0036] Step 5: The suspension mass distribution adjustment module 4 contains a suspension modal analysis model. An auxiliary water tank (containing water or other easily flowing high-density liquid) is suspended in the vehicle body. Liquid bladders are installed inside the front and rear subframes of the suspension, connected to the water tank via a pumping mechanism. Weight sensors are installed under the liquid bladders. Based on the input F-value and modal strain energy distribution, the suspension mass distribution adjustment module 4 determines the weight increase or decrease in each region (each liquid bladder) and activates the pumping mechanism to adjust the weight of the liquid bladders. The specific operation is as follows: if |F| is not less than the set value f, then F1 and F2 are decoupled to maintain the mass distribution of the suspension; if |F| is less than the set value f, then F1 and F2 are coupled; if F is negative and |F| is less than the set value f, then water is injected into the liquid bladder located in the modal frequency sensitive area of ​​the suspension (near the highest modal strain energy) through the pumping device to increase the mass of the modal frequency sensitive area of ​​the suspension and reduce the modal frequencies F1 of the suspension until F1 and F2 are decoupled; if F is positive and |F| is less than the set value f, then the liquid in the liquid bladder located in the modal frequency sensitive area of ​​the suspension is drained through the pumping device to reduce the mass of the modal frequency sensitive area of ​​the suspension and increase the modal frequencies F1 of the suspension until F1 and F2 are decoupled.

[0037] Example 1:

[0038] This embodiment is illustrated with an f value of 3Hz.

[0039] When three people are seated in the back of a certain vehicle, the vehicle load sensor measures the load changes of the four wheels and sends the load information to the vehicle load and suspension deformation analysis module 1. The multibody dynamics model, i.e., the suspension model, built into the vehicle load and suspension deformation analysis module 1, calculates the suspension deformation at this time (including the deformation information R of multiple suspension components) and transmits the suspension deformation signal to the suspension modal frequency analysis module 1.2. The modal frequency analysis model built into the suspension modal frequency analysis module 1.2 calculates the suspension natural frequencies of 99Hz and 150Hz at this time. The suspension modal frequency analysis module 1.2 outputs the suspension modal frequency signal, i.e., the aforementioned suspension natural frequencies of 99Hz and 150Hz, to the road vibration frequency acquisition module 3.

[0040] After the vehicle moves, the road vibration frequency acquisition module 3 measures the vibration frequency and corresponding amplitude of the current road surface, and outputs the road excitation frequency signal to the frequency decoupling judgment module 3. The road excitation frequency signal includes the top ten frequencies with larger amplitudes: 40, 50, 52, 62, 68, 85, 92, 101, 130, and 142 Hz.

[0041] According to the judgment rules, the frequency decoupling judgment module 3 determines that the 99Hz frequency of the suspension and the 101Hz frequency of the road surface may be coupled, resulting in a large amount of in-vehicle noise. Therefore, it is necessary to change the suspension mass to change the suspension's natural frequency. At this time, the frequency decoupling judgment module 3 transmits the suspension modal frequency to be adjusted signal to the suspension mass distribution adjustment module 4.

[0042] After receiving the command to adjust the natural frequency to 99Hz, the suspension mass distribution adjustment module 4 performs modal strain energy analysis on the finite element suspension model in that attitude. It automatically identifies locations with high strain energy and adds weight at these locations to reduce the suspension's natural frequency, thus decoupling the frequencies. It then transmits the suspension mass distribution signal to the suspension modal frequency analysis module 1.2 for re-analysis. The module automatically calculates the suspension's natural frequencies after adding weight to be 96Hz and 148Hz. At this point, the frequency decoupling judgment module 3, based on its rules, determines that the suspension frequency and the road surface frequency are decoupled, resulting in no noticeable noise inside the vehicle.

[0043] Example 2:

[0044] This embodiment is illustrated with an f value of 3Hz.

[0045] When three people are seated in the back of a certain vehicle, the vehicle load sensor measures the load changes of the four wheels and sends the load information to the vehicle load and suspension deformation analysis module 1. The multibody dynamics model, i.e., the suspension model, built into the vehicle load and suspension deformation analysis module 1 calculates the suspension deformation at this time (including the deformation information R of multiple suspension components) and transmits the suspension deformation signal to the suspension modal frequency analysis module 1.2. The modal frequency analysis model built into the suspension modal frequency analysis module 1.2 calculates the suspension natural frequencies of 102Hz and 150Hz at this time. The suspension modal frequency analysis module 1.2 outputs the suspension modal frequency signal, i.e., the aforementioned suspension natural frequencies of 102Hz and 150Hz, to the road vibration frequency acquisition module 3.

[0046] After the vehicle moves, the road vibration frequency acquisition module 3 measures the vibration frequency and corresponding amplitude of the current road surface, and outputs the road excitation frequency signal to the frequency decoupling judgment module 3. The road excitation frequency signal includes the top ten frequencies with larger amplitudes: 40, 50, 52, 62, 68, 85, 92, 101, 130, and 142 Hz.

[0047] According to the judgment rules, the frequency decoupling judgment module 3 determines that the 102Hz frequency of the suspension and the 101Hz frequency of the road surface may be coupled, resulting in a large amount of in-vehicle noise. Therefore, it is necessary to change the suspension mass to change the suspension's natural frequency. At this time, the frequency decoupling judgment module 3 transmits the suspension modal frequency to be adjusted signal to the suspension mass distribution adjustment module 4.

[0048] After receiving the command to adjust the natural frequency by 102Hz, the suspension mass distribution adjustment module 4 performs modal strain energy analysis on the finite element suspension model in that attitude. It automatically identifies locations with high strain energy and reduces weight at these locations to increase the suspension's natural frequency, thus decoupling the frequencies. It then transmits the suspension mass distribution signal to the suspension modal frequency analysis module 1.2 for re-analysis. The module automatically calculates the suspension's natural frequencies after the weight increase to be 105Hz and 152Hz. At this point, the frequency decoupling judgment module 3, based on its rules, determines that the suspension frequency and the road surface frequency are decoupled, resulting in no noticeable noise inside the vehicle.

[0049] In summary, this invention obtains the road vibration frequency by measuring the velocities of the wheel center in real time, analyzes the modal frequencies of the current suspension, determines whether the two are decoupled, and adjusts the suspension mass distribution based on the judgment result, thereby adjusting the suspension modal frequencies to maintain a constant decoupling between the suspension modal frequencies and the road vibration frequency. This achieves frequency decoupling across all road sections and scenarios, ensuring that vehicle road noise remains at a low level at all times. The adaptive frequency avoidance suspension system designed in this invention has a simple structure, simple suspension mass distribution adjustment operation, and low modification costs for suspension production and assembly. It can reduce road noise by combining data collected from multiple sensors to analyze and change the suspension mass distribution without affecting the normal function of the suspension, demonstrating good practical effects and meeting the requirements for reducing vehicle road noise in all scenarios.

[0050] In addition, the frequency decoupling judgment module 3 designed in this invention can also monitor the road surface condition in real time. When it is measured that the natural frequency of the road surface will change significantly, it indicates that the vehicle has traveled to a road section with different road surface conditions. At this time, the natural frequency of the suspension will be adjusted according to the natural frequency of the road to achieve decoupling.

[0051] It should be noted that the above description of the technical solutions is exemplary, and this specification may be embodied in different forms and should not be construed as limiting it to the technical solutions set forth herein. Rather, providing these descriptions will ensure that the disclosure of this invention is thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. Furthermore, the technical solutions of this invention are defined only by the scope of the claims. When using the terms "comprising," "having," and "including" as described in this specification, there may also be another part or other parts, and the terms used are generally singular but may also represent plural forms. Features of various embodiments of the invention may be combined or spliced ​​together partially or wholly, and may be implemented in various different configurations as will be fully understood by those skilled in the art. Embodiments of the invention may be implemented independently of each other or may be implemented together in an interdependent relationship.

Claims

1. An adaptive frequency avoidance suspension system based on road vibration, characterized in that: It includes a suspension modal frequency acquisition module (1), a road vibration frequency acquisition module (2), a frequency decoupling judgment module (3), and a suspension mass distribution adjustment module (4). The suspension modal frequency acquisition module (1) is used to construct a suspension state model based on the suspension load, suspension deformation and suspension mass distribution, and analyze and obtain the suspension modal frequencies F1 of each order; The road vibration frequency acquisition module (2) is used to convert the velocity signals in all directions at the wheel center into road vibration frequency signals and output several road vibration frequencies F2 with the highest amplitude. The frequency decoupling judgment module (3) is used to compare the mode frequencies F1 of the suspension with several road vibration frequencies F2 with the highest amplitude, to determine whether F1 and F2 are coupled, and output the coupling judgment result. The suspension mass distribution adjustment module (4) is used to adjust or maintain the mass distribution of the suspension according to the coupling judgment result, so that the mode frequencies F1 of the suspension are decoupled from the road vibration frequencies F2 with the highest amplitude. The suspension modal frequency acquisition module (1) includes a vehicle load and suspension deformation analysis module (1.1) and a suspension modal frequency analysis module (1.2). The vehicle load and suspension deformation analysis module (1.1) is used to construct a suspension model and receive suspension load signals. Based on the suspension load signals and the suspension model, the deformation of the suspension components is analyzed and the deformation information R of the suspension components is output. The suspension modal frequency analysis module (1.2) is used to construct the current suspension state model based on the deformation information R of the suspension components and the suspension mass distribution information M, and to analyze and output the modal frequencies F1 of the current suspension. The suspension mass distribution adjustment module (4) includes multiple liquid bladders fixed in the front and rear subframes of the suspension and a pumping device connected to the multiple liquid bladders, which can increase or decrease the mass of liquid in the multiple liquid bladders.

2. An adaptive frequency avoidance method based on the adaptive frequency avoidance suspension system according to claim 1, characterized in that: It includes the following steps: Step 1: Construct a suspension state model based on suspension load, suspension deformation, and suspension mass distribution, and analyze and obtain the modal frequencies F1 of the suspension. Step 2: Convert the velocity signals at the wheel center into road vibration frequency signals, and output several road vibration frequencies F2 with the highest amplitude; Step 3: Compare the various modal frequencies F1 of the suspension with several road vibration frequencies F2 with the highest amplitude to determine whether F1 and F2 are coupled, and output the coupling judgment result; Step 4: Adjust or maintain the mass distribution of the suspension based on the coupling judgment results, so that the modal frequencies F1 of the suspension are decoupled from the road vibration frequencies F2 with the highest amplitude.

3. The adaptive frequency avoidance method as described in claim 2, characterized in that: The method for obtaining the suspension deformation in step one is as follows: construct a suspension model, receive suspension load signals, and analyze the suspension load signals and suspension model to obtain the deformation information R of the suspension components.

4. The adaptive frequency avoidance method as described in claim 3, characterized in that: The method for analyzing and obtaining the modal frequencies F1 of the suspension in step one is as follows: construct the current suspension state model based on the deformation information R of the suspension components and the suspension mass distribution information M, and analyze and obtain the modal frequencies F1 of the current suspension.

5. The adaptive frequency avoidance method as described in claim 2, characterized in that: The method for determining whether F1 and F2 are coupled in step three is as follows: compare each modal frequency F1 of the suspension with several road vibration frequencies F2 with the highest amplitude, calculate the difference F between each modal frequency F1 of the suspension and several road vibration frequencies F2 with the highest amplitude. If |F| is not less than the set value f, then F1 and F2 are decoupled; if |F| is less than the set value f, then F1 and F2 are coupled.

6. The adaptive frequency avoidance method as described in claim 5, characterized in that: In step four, the method for adjusting or maintaining the suspension mass distribution based on the coupling judgment result, so that the suspension modal frequencies F1 and several road vibration frequencies F2 with the highest amplitude are decoupled is as follows: if F1 and F2 are decoupled, the current suspension mass distribution state is maintained; if F1 and F2 are coupled, the current suspension mass distribution state is adjusted until F1 and F2 are decoupled.

7. The adaptive frequency avoidance method as described in claim 6, characterized in that: The method for adjusting the current suspension mass distribution state until F1 and F2 are decoupled is as follows: water is injected or drained into multiple fluid bladders distributed in the front and rear subframes of the suspension through a pumping device to adjust the mass of each fluid bladder and change the current suspension mass distribution state until F1 and F2 are decoupled.

8. The adaptive frequency avoidance method as described in claim 7, characterized in that: If F is negative and |F| is less than the set value f, water is injected into the fluid bladder located in the suspension modal frequency sensitive area to increase the mass of the suspension modal frequency sensitive area and reduce the modal frequencies F1 of the suspension until F1 and F2 are decoupled; if F is positive and |F| is less than the set value f, the liquid in the fluid bladder located in the suspension modal frequency sensitive area is drained to reduce the mass of the suspension modal frequency sensitive area and increase the modal frequencies F1 of the suspension until F1 and F2 are decoupled.

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