Method, unit and vehicle for adjusting wheel vibration frequency of a vehicle

Abstract

The present invention provides a method, unit, and vehicle for adjusting the wheel vibration frequency of a vehicle. The vehicle has ABS and a semi-active suspension (3). The method includes a data acquisition step (S1), a judgment step (S2), and an output step (S3). The data acquisition step (S1) acquires the current wheel speed (11), the braking state (12), and the working state (13) of the vehicle. The judgment step (S2) determines, based on the data acquired in the data acquisition step (S1), whether the vehicle is braking, whether the ABS is working, whether the wheel acceleration is greater than a preset acceleration threshold, and whether the wheel vibration frequency is within a preset vibration frequency range. If the judgment result of the judgment step (S2) is yes, the output step (S3) outputs a command to the semi-active suspension (3) to adjust its suspension damping.

Description

Technical Field

[0001] This invention relates to a method, unit, and vehicle for adjusting the wheel vibration frequency of a vehicle, and particularly to a method based on semi-active suspension for improving NVH (Noise, Vibration, and Harshness) characteristics during braking on ice with ABS engaged. Background Technology

[0002] ESP / ABS has become standard in automobiles, and the NVH (noise, vibration, and harshness) issues it causes on various road surfaces are receiving increasing attention. ABS is a logic threshold control based on wheel slip ratio. During ABS braking, the ABS adjusts the wheel cylinder pressure according to the real-time wheel slip ratio. The periodic increase or decrease in wheel cylinder pressure can, under certain circumstances, cause the wheel to vibrate at a specific frequency, thus resonating with the suspension. Once resonance occurs, it causes severe vibrations in the front axle and body, affecting vehicle stability and comfort. This phenomenon is particularly noticeable on roads with low surface adhesion.

[0003] In particular, in some vehicles, braking on ice causes the wheels and suspension to resonate, resulting in severe vibrations in the front axle. This leads to longer braking distances, and the intense vibrations can cause driver discomfort.

[0004] Currently, when the aforementioned resonance occurs, adjusting the ABS boost / depressurization threshold and staggering the boost / depressurization of the left and right wheels can help avoid the resonance frequency to some extent. However, this has limited effect on many vehicles, and severe vibrations still occur. Summary of the Invention

[0005] Depending on the specific aspects, the purpose of this invention is to eliminate wheel and suspension resonance caused by wheel vibration due to ABS during braking on low-friction surfaces, thereby optimizing NVH characteristics.

[0006] Furthermore, the present invention aims to solve or alleviate other technical problems existing in the prior art.

[0007] The present invention addresses the aforementioned problems by providing a method, unit, and vehicle for adjusting the wheel vibration frequency of a vehicle. Specifically, according to one aspect of the present invention, the following is provided:

[0008] A method for adjusting the wheel vibration frequency of a vehicle, the vehicle having ABS and semi-active suspension, wherein the method includes a data acquisition step, a judgment step, and an output step, wherein...

[0009] The data acquisition step collects the vehicle's current wheel speed, the vehicle's braking status, and the ABS's operating status.

[0010] The judgment step, based on the data collected in the acquisition step, determines whether the vehicle is braking, whether the ABS is engaged, whether the wheel acceleration is greater than a preset acceleration threshold, and whether the wheel vibration frequency is within a preset vibration frequency range.

[0011] If the judgment results of the judgment steps are all yes, then the output step outputs a command to the semi-active suspension to adjust its suspension damping.

[0012] According to another aspect of the present invention, a unit for adjusting the wheel vibration frequency of a vehicle having ABS and a semi-active suspension is provided, wherein the unit includes a data acquisition module, a judgment module, and an output module that are communicatively connected to each other, wherein...

[0013] The data acquisition module collects the vehicle's current wheel speed, the vehicle's braking status, and the ABS's operating status.

[0014] The judgment module determines, based on the data collected by the acquisition module, whether the vehicle is braking, whether the ABS is engaged, whether the wheel acceleration is greater than an acceleration threshold, and whether the wheel vibration frequency is within the vibration frequency range.

[0015] If all the judgment results of the judgment module are yes, then the output module outputs a command to the semi-active suspension to adjust its suspension damping.

[0016] According to another aspect of the present invention, a vehicle is provided, wherein the vehicle has any of the above-described units. Attached Figure Description

[0017] Referring to the accompanying drawings, the above and other features of the present invention will become apparent, wherein,

[0018] Figure 1 A flowchart illustrating a method according to the present invention is shown;

[0019] Figure 2 A schematic diagram of signal transmission according to a method of the present invention is shown;

[0020] Figure 3 An example of logic control according to a method of the present invention is shown;

[0021] Figure 4 A schematic diagram of a unit according to the present invention is shown. Detailed Implementation

[0022] It is readily understood that, based on the technical solution of this invention, those skilled in the art can propose various interchangeable structural methods and implementations without altering the essential spirit of the invention. Therefore, the following detailed embodiments and accompanying drawings are merely illustrative examples of the technical solution of this invention and should not be considered as the entirety of the invention or as limitations or restrictions on the technical solution of this invention.

[0023] The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly used in this specification are defined relative to the structures shown in the accompanying drawings. These are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive. Furthermore, the terms "first," "second," "third," and similar expressions are used for descriptive and distinguishing purposes only and should not be construed as indicating or implying the relative importance of the corresponding components.

[0024] refer to Figures 1 to 3 They respectively illustrate a flowchart, a signal transmission diagram, and a logic control example of a method according to the present invention.

[0025] The method is used to adjust the wheel vibration frequency of a vehicle equipped with ABS and a semi-active suspension 3. The method includes a data acquisition step S1, a judgment step S2, and an output step S3.

[0026] The data acquisition step S1 acquires the vehicle's current wheel speed 11, the vehicle's braking status 12, and the ABS operating status 13.

[0027] The judgment step S2, based on the data collected in the acquisition step S1, determines whether the vehicle is braking, whether the ABS is active, whether the wheel acceleration is greater than a preset acceleration threshold, and whether the wheel vibration frequency is within a preset vibration frequency range.

[0028] If the judgment result of the judgment step S2 is yes, then the output step S3 outputs a command to the semi-active suspension 3 to adjust its suspension damping.

[0029] It should be noted that semi-active suspension (also known as semi-active (type) suspension) typically consists of variable damping shock absorbers or variable stiffness springs. It responds according to road conditions and vehicle driving status, especially dynamically adjusting suspension damping based on the vehicle's vertical direction. By collecting road information through sensors, the controller uses pre-downloaded control algorithms to calculate and adjust the transient load on the wheels, thereby achieving optimal damping force in the suspension system. This effectively improves vehicle comfort on uneven roads. It compensates for the shortcomings of passive suspension systems while achieving or approaching the damping effect of active suspension. Simultaneously, its energy consumption is significantly lower than that of active suspension, overcoming the limitations of active suspension in practical applications and offering high cost-effectiveness and broad application prospects.

[0030] Semi-active suspension can offer different performance characteristics depending on road conditions, adjusting suspension performance by changing only the damping without altering the suspension stiffness. Additionally, ABS stands for Antilock Braking System.

[0031] The judgment conditions specified in the judgment step S2 are used to ensure that the vehicle is braking on a road surface with a low coefficient of adhesion (hereinafter referred to as low-adhesion road surface) and that the method is executed with ABS engaged. Specifically, the method determines whether the vehicle is braking and whether the ABS is active by collecting the vehicle's braking state 12 and the ABS's operating state 13, and obtains the wheel acceleration and wheel vibration frequency by collecting the vehicle's current wheel speed 11. These values ​​are then compared with preset acceleration thresholds and preset vibration frequency ranges for judgment. The numerical range of the low road surface adhesion coefficient is, for example, 0.1-0.5.

[0032] The reason for considering wheel acceleration is to ensure that the vehicle's current driving condition is indeed on a low-friction surface, preventing false triggering of this method. For example, when braking on a bad road (such as a cobblestone road, Belgian road, etc.), the wheels will also vibrate violently due to the road surface excitation. However, the amplitude and frequency of wheel vibration on a bad road are different from those on a low-friction surface, so the trigger threshold can effectively prevent false triggering on bad roads. Additionally, the reason for considering wheel vibration frequency is to avoid unnecessary execution of this method, as its purpose is to prevent resonance between the wheels and the suspension. Resonance requires that the wheel vibration frequency and the suspension vibration frequency are the same. Therefore, the execution of this method has certain requirements regarding the range of the wheel's own vibration frequency. Wheel vibration outside the preset wheel vibration frequency will not cause resonance and therefore does not need to be considered. Furthermore, this preset condition can also prevent false triggering of this method under some unnecessary driving conditions. Optionally, the vehicle's current wheel speed 11 is obtained through the vehicle's wheel speed sensor, and / or the vehicle's braking state 12 is obtained through the state of the vehicle's brake light switch. Of course, the corresponding data can also be obtained directly through the vehicle's wheel acceleration sensors and wheel vibration frequency sensors.

[0033] The output command in step S3 is sent to the semi-active suspension 3 to adjust its suspension damping (e.g., increase the suspension damping), thereby changing the vibration characteristics and frequency of the wheel and differentiating it from the vibration frequency of the suspension, thus avoiding resonance. Furthermore, the current suspension damping value can be obtained in real time from the semi-active suspension 3 for monitoring purposes.

[0034] The suspension damping can optionally be applied to the front axle wheels of the vehicle, because the front axle wheels are often the ones that experience severe vibrations under the conditions triggered by this method. It should be understood that "front axle wheels" indicates that the suspension damping acts simultaneously on all the front axle wheels. Of course, depending on the actual situation, the suspension damping can also be adjusted for the rear axle wheels or individually for each wheel. This depends on the specific design of the semi-active suspension and the actual needs of the situation.

[0035] If the result of the judgment step S2 is yes, then the output step S3 can also output a command to the ABS to adjust the pressure and / or pressure increase / decrease slope of its brake wheel cylinder. By adjusting the pressure and / or pressure increase / decrease slope of the brake wheel cylinder, the vibration frequency of the wheel can be adjusted in conjunction with the adjustment of the suspension damping of the semi-active suspension 3. The brake wheel cylinder is a device used to convert hydraulic force into mechanical force. During braking, brake fluid enters the brake wheel cylinder, pushing the brake piston, thereby causing the friction pads to contact the brake disc, generating friction to achieve braking.

[0036] To better calculate wheel acceleration and wheel vibration frequency, the acquisition step S1 also acquires the vehicle's longitudinal acceleration 14, lateral acceleration 15, and / or yaw rate 16. The longitudinal acceleration is the acceleration along the vehicle's axis, representing the degree to which the front and rear ends of the vehicle tend to lift or drop during travel; the lateral acceleration is the acceleration along a direction perpendicular to the vehicle's direction of travel; and the yaw rate is the angular velocity of the vehicle rotating about its vertical axis in its coordinate system, which typically occurs when the vehicle is turning.

[0037] Upon completion of this method, if the vehicle has departed from the driving condition triggered by this method (no longer braking, ABS not activated, or the vehicle not on a low-friction surface), i.e., if one or more of the results of the judgment step S2 are negative, then the output step S3 can also output a command to the semi-active suspension 3 to adjust its suspension damping back to its original state, so that the vehicle's characteristics can still be applied to other driving conditions. Of course, if the brake wheel cylinder pressure and / or pressure relief slope are also adjusted simultaneously during the execution of this method, these two values ​​can also be adjusted back to their original values.

[0038] The method can be executed via the vehicle's ESP2 or ABS. ESP stands for Electronic Stability Program, commonly known as the vehicle's electronic stability system. If the vehicle is not equipped with ESP, the method can be executed using ABS. Therefore, this method can be well applied to various existing vehicle models, exhibiting excellent compatibility and saving application costs.

[0039] Furthermore, it should be noted that the order of the judgment steps is not strictly required, and they can even be performed simultaneously. Figure 3 For example, in the judgment step S2, it is first determined whether the vehicle is braking and whether the ABS is activated S21. If so, it is then determined whether the acceleration of the wheel is greater than the acceleration threshold S22. If so, it is then determined whether the vibration frequency of the wheel is within the vibration frequency range S23. If any of these judgments result in a negative outcome, the process returns to the previous judgment step.

[0040] The reason for adopting this decision-making sequence is that the vehicle's braking state and ABS state can be obtained directly without any calculation. Therefore, if the conditions are not met, the execution of this method can be avoided, improving operational efficiency. Furthermore, wheel acceleration can be obtained from wheel speed more quickly than wheel vibration frequency, similarly improving the overall operational efficiency of the method. Of course, if wheel acceleration sensors and wheel vibration frequency sensors are used directly, other step sequences can be considered for executing this method. This method can be presented in software form (i.e., a logical algorithm).

[0041] The specific values ​​of the various physical quantities mentioned in this method, such as suspension damping, wheel acceleration threshold, and wheel vibration frequency range, vary greatly depending on the vehicle model. Therefore, they need to be determined on a case-by-case basis. After identifying the specific vehicle, these values ​​can be determined and adjusted through experience or experimentation.

[0042] refer to Figure 4 The diagram illustrates a schematic representation of a unit 100 according to the present invention. Since the specific shapes and connection methods of the various components are not the subject of this invention, for clarity and simplicity, all these components are schematically shown as structural modules. Those skilled in the art can select appropriate module shapes and connection methods based on the structural diagram. Furthermore, the given structural diagram is one embodiment of the present invention, and those skilled in the art can make various modifications without departing from the spirit of the invention after referring to the diagram; these modifications should also be within the scope of protection of the present invention.

[0043] The unit 100 is used to adjust the wheel vibration frequency of the vehicle, which has ABS and a semi-active suspension 3. The unit 100 includes a data acquisition module 101, a judgment module 102, and an output module 103 that are communicatively connected to each other.

[0044] The acquisition module 101 acquires the vehicle's current wheel speed 11, the vehicle's braking status 12, and the ABS operating status 13.

[0045] The judgment module 102 determines, based on the data collected by the acquisition module 101, whether the vehicle is braking, whether the ABS is active, whether the wheel acceleration is greater than an acceleration threshold, and whether the wheel vibration frequency is within the vibration frequency range.

[0046] If the judgment result of the judgment module 102 is yes, then the output module 103 outputs a command to the semi-active suspension 3 to adjust its suspension damping.

[0047] The features and characteristics of this unit 100 can be understood by referring to the description of the method above. Specifically, the unit 100 can be configured to perform any of the methods described above. For example, the acquisition module 101 is used to perform the acquisition step S1, the judgment module 102 is used to perform the judgment step S2, and the output module 103 is used to perform the output step S3. The unit 100 can be integrated into the vehicle's ESP or ABS.

[0048] It should be understood that the unit 100 of the present invention can be installed in various vehicles, including gasoline vehicles, diesel vehicles, passenger cars, trucks, buses, hybrid vehicles, pure electric vehicles, etc. Therefore, the subject matter of the present invention also aims to protect various vehicles equipped with the unit 100 of the present invention.

[0049] It should be understood that all the above preferred embodiments are exemplary and not restrictive, and various modifications or variations made by those skilled in the art to the specific embodiments described above under the concept of the present invention should be within the legal protection scope of the present invention.

Claims

1. A method for adjusting the frequency of wheel vibrations of a vehicle, the vehicle having an ABS and a semi-active suspension (3), characterized in that, The method includes a data acquisition step (S1), a judgment step (S2), and an output step (S3), wherein, The data acquisition step (S1) acquires the current wheel speed (11) of the vehicle, the braking status of the vehicle (12) and the working status of the ABS (13). The judgment step (S2) determines, based on the data collected in the acquisition step (S1), whether the vehicle is braking, whether the ABS is active, whether the wheel acceleration is greater than a preset acceleration threshold, and whether the wheel vibration frequency is within a preset vibration frequency range. The wheel vibration frequency is obtained either by collecting the vehicle's current wheel speed (11) or by using a wheel vibration frequency sensor. If the judgment result of the judgment step (S2) is yes, then the output step (S3) outputs a command to the semi-active suspension (3) to adjust its suspension damping.

2. The method of claim 1, wherein, If the result of the judgment step (S2) is yes, then the output step (S3) also outputs a command to the ABS to adjust the pressure of its brake wheel cylinder and / or the pressure increase / decrease slope.

3. The method of claim 1, wherein, The acquisition step (S1) also acquires the vehicle's longitudinal acceleration (14), lateral acceleration (15), and / or yaw rate (16).

4. The method of claim 1, wherein, The current wheel speed (11) of the vehicle is obtained by the vehicle's wheel speed sensor, and / or the braking state (12) of the vehicle is obtained by the state of the vehicle's brake light switch.

5. The method according to claim 1, characterized in that, If one or more of the results of the judgment step (S2) are negative, the output step (S3) also outputs a command to the semi-active suspension (3) to adjust its suspension damping back to its original state.

6. The method of claim 1, wherein, The method is performed by the vehicle’s ESP (2) or ABS.

7. The method of claim 1, wherein, The suspension damping is applied to the front axle wheels of the vehicle.

8. The method of claim 1, wherein, In the judgment step (S2), it is first determined whether the vehicle is braking and whether the ABS is working (S21). If so, it is then determined whether the acceleration of the wheel is greater than the acceleration threshold (S22). If so, it is then determined whether the vibration frequency of the wheel is within the vibration frequency range (S23).

9. A unit (100) for adjusting the frequency of the wheel vibrations of a vehicle, said vehicle having an ABS and a semi-active suspension (3), characterized in that, The unit (100) includes a data acquisition module (101), a judgment module (102), and an output module (103) that are communicatively connected to each other. The acquisition module (101) acquires the vehicle's current wheel speed (11), the vehicle's braking status (12), and the ABS's working status (13). The judgment module (102) determines, based on the data collected in the acquisition module (101), whether the vehicle is braking, whether the ABS is active, whether the wheel acceleration is greater than the acceleration threshold, and whether the wheel vibration frequency is within the vibration frequency range. The wheel vibration frequency is obtained either by collecting the vehicle's current wheel speed (11) or by using a wheel vibration frequency sensor. If the judgment result of the judgment module (102) is yes, then the output module (103) outputs a command to the semi-active suspension (3) to adjust its suspension damping.

10. The unit (100) according to claim 9, characterized in that The unit (100) is configured to perform the method according to any one of claims 2 to 8.

11. A vehicle, characterized in that, The vehicle has a unit (100) according to claim 9 or 10.

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