Method for evaluating tire shake index, tire, and vehicle

Abstract

This invention discloses a method for evaluating tire vibration index, a tire, and a vehicle. The evaluation method includes: under preset vehicle speed and preset road conditions, measuring and obtaining a first relationship function of the radial vibration force of the left front wheel in the vertical direction with respect to time, and measuring and obtaining a second relationship function of the radial vibration force of the right front wheel in the vertical direction with respect to time; determining the first Fourier series of the first relationship function as the third relationship function, determining the first Fourier series of the second relationship function as the fourth relationship function, and determining the average of the peak-to-peak value of the third relationship function and the peak-to-peak value of the fourth relationship function as the tire vibration index parameter; when the vibration index parameter is less than a preset threshold, the tire vibration index is deemed qualified. This invention can determine the vibration index of the tire that affects the vehicle vibration condition, and based on this vibration index, the tire can be effectively optimized, and production requirements for the tire can be proposed.

Description

Technical Field

[0001] This invention relates to the field of vehicle tire vibration index technology, and particularly to a method for evaluating tire vibration index, a tire, and a vehicle. Background Technology

[0002] With the continuous progress of society and the economy, people have increasingly higher requirements for the ride comfort of passenger vehicles. Especially when the vehicle is traveling at high speed, the driver is more focused and more likely to notice ride comfort issues. At this time, abnormal, continuous, and repetitive vibrations of the vehicle will bring a poor riding experience to the driver and other passengers. The causes of vehicle vibration are mainly two-part: one is excessive excitation from the excitation source, and the other is resonance problems in the transmission path. As the only part of the vehicle in contact with the ground, the tires are one of the excitation factors and key transmission paths that cause vehicle vibration. In related technologies, accelerometers are usually placed at the vehicle seats to detect the acceleration of the seats. The vibration status of the vehicle is evaluated by the value of the seat acceleration. However, it is unclear which tire performance parameter affects the vehicle vibration, that is, it is unclear which specific tire performance parameter is positively correlated with the vehicle vibration. This makes it difficult to effectively optimize the tires and to propose production requirements for the relevant tire indicators. Summary of the Invention

[0003] Therefore, one objective of this invention is to provide a method for evaluating tire vibration index, which can determine the vibration index that affects vehicle vibration, and based on the vibration index, the tire can be effectively optimized and production requirements can be proposed for the tire.

[0004] This invention also provides tires that are deemed to have qualified vibration indexes by applying the above-mentioned evaluation method for tire vibration indexes.

[0005] Embodiments of the present invention also provide a vehicle including the above-described tires.

[0006] According to a first aspect of the present invention, a method for evaluating tire vibration index includes: at a preset vehicle speed and under preset road conditions, measuring and obtaining a first relationship function of the radial vibration force of the left front wheel of the vehicle in the vertical direction with respect to time, and measuring and obtaining a second relationship function of the radial vibration force of the right front wheel of the vehicle in the vertical direction with respect to time; determining the first Fourier series of the first relationship function as a third relationship function, determining the first Fourier series of the second relationship function as a fourth relationship function, determining the average of the peak-to-peak value of the third relationship function and the peak-to-peak value of the fourth relationship function as a tire vibration index parameter, determining a preset threshold based on the preset vehicle speed and the preset road conditions; determining that the tire vibration index is qualified if the vibration index parameter is less than the preset threshold; and determining that the tire vibration index is unqualified if the vibration index parameter is greater than or equal to the preset threshold.

[0007] The tire vibration index evaluation method according to embodiments of the present invention has at least the following beneficial effects:

[0008] The first relationship function of the radial vibration force of the left front wheel in the vertical direction with respect to time is obtained by measurement, and the second relationship function of the radial vibration force of the rear front wheel in the vertical direction with respect to time is obtained by measurement. First-order Fourier expansions are performed on the first and second relationship functions to obtain the third and fourth relationship functions. The third relationship function can be understood as a function of the first-order radial vibration force of the left front wheel with respect to time, and the fourth relationship function can be understood as a function of the first-order radial vibration force of the right front wheel with respect to time. The peak-to-peak value of the third relationship function and the average peak-to-peak value of the fourth relationship function are then determined as tire vibration index parameters. The obtained vibration index parameters are positively correlated with the vehicle's vibration condition; the larger the vibration index parameter, the more severe the vehicle vibration, and the smaller the vibration index parameter, the milder the vehicle vibration. Whether the tire vibration index is qualified is determined by whether the vibration index parameter is greater than or equal to a preset threshold. Evaluation of the tire vibration index allows for effective tire optimization, thereby setting production requirements for relevant tire indicators to ensure weaker vibration at high speeds, improving the driving experience and ensuring driving safety.

[0009] According to some embodiments of the present invention, the preset vehicle speed is 100 km / h to 140 km / h.

[0010] According to some embodiments of the present invention, the preset threshold is 120N to 140N.

[0011] According to some embodiments of the present invention, obtaining a first relationship function of the radial vibration force of the left front wheel of a vehicle in the vertical direction with respect to time by measurement includes the following steps:

[0012] A first acceleration sensor is installed at the left front steering knuckle of the vehicle. The fifth relationship function of the acceleration of the left front wheel in the vertical direction with respect to time is obtained through the first acceleration sensor. The product of the fifth relationship function and the mass of the left front wheel is determined to be the first relationship function.

[0013] According to some embodiments of the present invention, obtaining a second relationship function of the radial vibration force of the right front wheel of a vehicle in the vertical direction with respect to time by measurement includes the following steps:

[0014] A second acceleration sensor is installed at the right front steering knuckle of the vehicle, and the sixth relationship function of the acceleration of the left front wheel in the vertical direction with respect to time is obtained through the second acceleration sensor;

[0015] The product of the sixth relation function and the mass of the right front wheel is determined to be the second relation function.

[0016] According to some embodiments of the present invention, after determining that the tire vibration index is qualified, the following steps are included:

[0017] Multiple continuously arranged gradient intervals are divided from the preset threshold to zero, and multiple one-to-one corresponding jitter levels are established based on the multiple gradient intervals;

[0018] The vibration level of the tire is determined based on the gradient range into which the vibration index parameters fall.

[0019] According to some embodiments of the present invention, the widths of the plurality of gradient intervals are arranged in an increasing trend from the preset threshold to zero.

[0020] According to some embodiments of the present invention, the width of the gradient interval is 10N to 15N.

[0021] The tire according to the second aspect embodiment of the present invention is obtained by applying the tire vibration index evaluation method of the first aspect embodiment.

[0022] The tire according to the embodiments of the present invention has at least the above-mentioned beneficial effects since it is determined to be qualified by the evaluation method of tire vibration index of the first aspect embodiment, and will not be repeated here.

[0023] A vehicle according to a third aspect of the present invention includes the tires of the second aspect of the present invention.

[0024] The vehicle according to the embodiments of the present invention, having included the tires of the second aspect embodiment, has at least the aforementioned beneficial effects, which will not be repeated here.

[0025] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0027] Figure 1 This is a flowchart illustrating the steps of a method for evaluating tire vibration index according to some embodiments of the present invention;

[0028] Figure 2 This is a flowchart illustrating the steps of a method for evaluating tire vibration index according to some embodiments of the present invention;

[0029] Figure 3 This is a graph showing the relationship between the radial vibration force of a wheel in the vertical direction and time in some embodiments of the present invention;

[0030] Figure 4 This is a schematic diagram illustrating the principle of vibration transmission in a vehicle according to some embodiments of the present invention;

[0031] Figure 5 These are experimental data diagrams of vehicles according to some embodiments of the present invention. Detailed Implementation

[0032] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0033] With the continuous progress of society and economy, people have higher and higher requirements for the ride comfort of passenger vehicles. Especially when the vehicle is driving at high speed, the driver is more focused and more likely to perceive and discover some ride comfort problems. At this time, abnormal, continuous and repeated shaking of the vehicle will bring a bad riding experience to the driver and other passengers. The causes of vehicle shaking are mainly two parts: one is that the excitation source is too large, and the other is that there are problems such as resonance in the transmission path. As the only part of the vehicle that is in contact with the ground, the tire is one of the excitation factors and key transmission paths that cause vehicle shaking.

[0034] In related technologies, accelerometers are typically placed in the vehicle's seats to detect the seat's acceleration. The vehicle's vibration is evaluated by measuring the seat's acceleration. However, it is unclear which tire performance parameter affects the vehicle's vibration, or which specific tire performance parameter is positively correlated with the vehicle's vibration. This makes it difficult to effectively optimize the tires and to set production requirements for the tire's relevant indicators.

[0035] The vibration is mainly because a tire is not an ideally uniformly distributed component. This manifests as the force generated at the tire-ground contact point fluctuating continuously after the tire rolls 360° along the ground. (Refer to...) Figure 4 As shown, when a vehicle is moving, the road surface generates an excitation source on the wheels. This excitation source is transmitted through the suspension to the chassis, and then from the chassis to the body and powertrain. Considering the excitation source, tires will vibrate when their own uniformity is poor. Analyzing the intensity of vibration generated by the tire as an excitation source requires establishing the relationship between the tire and high-speed vibration. Currently, due to the complexity of the transmission path or the influence of various factors, it is difficult to determine the pattern by which the excitation source is transmitted to the vehicle body. Therefore, it is difficult to identify which tire performance parameter is related to vehicle body vibration.

[0036] Through extensive experiments, the inventors discovered that a certain vehicle model suffers from tire vibration intensity that leads to a poor passenger experience. After conducting multiple rounds of optimization tests on two brands of tires and performing Fourier expansion on the test data, they found that the peak-to-peak value of the first-order Fourier series of the radial vibration force of the tire along the Z-direction plays a crucial role in determining the vibration of the vehicle at speeds above 100 km / h. Optimizing this indicator can solve the problem of high-speed vehicle vibration.

[0037] Specifically, refer to Figure 4 and Figure 5 The table shows data obtained from experiments conducted on vehicles at speeds exceeding 100 km / h under specific road conditions. RFV refers to the peak-to-peak amplitude of the first function relating the radial vibration force of the left or right front wheel in the Z-direction to time. It's important to note that peak-to-peak amplitude (RFV) is the algebraic difference between the maximum and minimum function values; it can also be understood as the difference between the highest and lowest signal values ​​within a period. Each RFV column contains two data points: one for the left front wheel and one for the right front wheel. R1H refers to the peak-to-peak amplitude of the first Fourier series of the first function relating the left or right front wheel. Similarly, R2H represents the peak-to-peak amplitude of the second Fourier series, and R3H represents the peak-to-peak amplitude of the third Fourier series. The overall vehicle performance table uses the acceleration data from the accelerometer on the seat to determine whether the vehicle's vibration level meets the acceptable standards. Observation reveals a correlation between the average R1H of the two front wheels and the overall vehicle performance. Based on the data in the graph, it can be concluded that when the average R1H of the two front wheels is less than 137N, the vehicle exhibits no vibration; when the average R1H of the two front wheels is greater than 137N, the vehicle exhibits vibration. The data in the other columns are not correlated with whether the vehicle vibrates. This result is a pattern obtained through extensive experimentation. Figure 5 The data presented here is merely example data from one experiment, used for illustrative purposes. Taking the first relational function of the left front wheel as an example, refer to... Figure 4 The image shows a comparison of the first relational function expanded to Fourier series of different orders. The solid line representing the waveform generated by RFV is the first relational function. Figure 4 The length of the RFV arrow represents the peak-to-peak value of the first relational function, and the other different dashed lines represent Fourier series of different orders expanded from the first relational function. Specifically, the dashed line at 40sin(θ-10) represents the first-order Fourier series of the waveform generated by the RFV. Figure 4 The length of the R1H arrow represents the peak-to-peak value of the first-order Fourier series. R1H is 80N. The dashed line of 25sin(2θ-30) represents the second-order Fourier series of the RFV generated waveform, the dashed line of 15sin(3θ-45) represents the third-order Fourier series of the RFV generated waveform, and the dashed line of 4sin(9θ-5) represents the fourth-order Fourier series of the RFV generated waveform.

[0038] Based on this, refer to Figure 1 As shown in the figure, this embodiment of the invention proposes a method for evaluating tire vibration index, which can determine the vibration index parameters of the tire and judge whether the tire vibration index is qualified by the vibration index parameters. Specifically, the evaluation method for tire vibration index includes steps S100, S200, S300, S400 and S500.

[0039] Among them, reference Figure 1 As shown, in step S100: under preset vehicle speed and preset road conditions, the first relationship function of the radial vibration force of the left front wheel of the vehicle in the vertical direction with respect to time is obtained by measurement, and the second relationship function of the radial vibration force of the right front wheel of the vehicle in the vertical direction with respect to time is obtained by measurement.

[0040] In this step, it is necessary to obtain the first and second relational functions mentioned above under preset vehicle speed and preset road conditions, because different vehicle speeds and road conditions will affect the tire vibration. The radial vibration force of the tire in the vertical direction can be understood as the radial vibration force of the tire in the Z direction, and the radial vibration force of the tire in the Z direction has a significant impact on the vehicle vibration.

[0041] Reference Figure 1 As shown, step S200: Determine the first Fourier series of the first relational function as the third relational function, determine the first Fourier series of the second relational function as the fourth relational function, and determine the average of the peak-to-peak value of the third relational function and the peak-to-peak value of the fourth relational function as the tire vibration index parameter.

[0042] In this step, both the first and second relational functions are periodic functions and can be expanded using Fourier transform. In some embodiments, both the first and second relational functions are aperiodic functions and can be transformed using Fourier transform before Fourier expansion. The third relational function can be understood as a trigonometric function used to approximate the first relational function, and the fourth relational function can be understood as a trigonometric function used to approximate the second relational function. Extensive experimental data revealed that the average of the peak-to-peak values ​​of the third and fourth relational functions is positively correlated with vehicle vibration; the larger this average value, the more severe the vehicle vibration. Therefore, this average value can be determined as a parameter indicating tire vibration.

[0043] Step S300: Determine the preset threshold based on the preset vehicle speed and preset road conditions.

[0044] It should be noted that since vehicle speed and road conditions both affect vehicle vibration, the preset threshold will differ under different preset vehicle speeds and road conditions. There can be multiple preset thresholds; a specific vehicle speed and road condition can correspond to a specific preset threshold. These preset thresholds can be determined through extensive experimentation. The resulting vibration index parameter is positively correlated with the vehicle's vibration condition: the larger the vibration index parameter, the more severe the vehicle vibration; the smaller the vibration index parameter, the milder the vehicle vibration.

[0045] Reference Figure 1 As shown, in step S400: when the vibration index parameter is less than the preset threshold, the vibration index of the tire is determined to be qualified.

[0046] Reference Figure 1 As shown, in step S500: when the vibration index parameter is greater than or equal to the preset threshold, the tire vibration index is determined to be unqualified.

[0047] In this step, because the vibration index parameter is positively correlated with the vehicle's vibration condition, the tire's vibration index can be evaluated using this parameter. Specifically, it can be judged by comparing the vibration index parameter with a preset threshold, which can be obtained through extensive experimentation. This allows for effective tire optimization and sets production requirements for relevant tire indicators. During tire production, the vibration index parameter must be kept below the preset threshold. When a qualified tire is produced using a certain production parameter or process, mass production can continue using the same parameters or process, saving time on parameter adjustments. This ensures less vibration when the vehicle is traveling at high speeds, improving the driving experience and guaranteeing driving safety.

[0048] It is understandable that in some embodiments, the preset vehicle speed can be 100km / h to 140km / h to ensure that the tire vibration index parameters are obtained under high-speed driving conditions, allowing for optimization of tire parameters for high-speed driving scenarios. In some embodiments, the preset threshold is 120N to 140N. This can be understood as an empirical value obtained through a large amount of experimental data. It should also be noted that since this invention is aimed at high-speed driving scenarios, in reality, vehicles travel at slower speeds on rougher road surfaces, which does not conform to high-speed driving scenarios. When determining the above vibration index parameters, it should be ensured that the vehicle is driving on a relatively smooth road surface to ensure that the obtained tire vibration index parameters are relatively accurate.

[0049] Understandably, in some embodiments, obtaining a first relationship function of the radial jitter force of the vehicle's left front wheel in the vertical direction with respect to time by measuring includes the following steps:

[0050] A first acceleration sensor is installed at the left front steering knuckle of the vehicle, and the fifth relationship function of the acceleration of the left front wheel in the vertical direction with respect to time is obtained through the first acceleration sensor;

[0051] The product of the fifth relation function and the mass of the left front wheel is determined to be the first relation function.

[0052] In this step, it is convenient to set the first acceleration sensor at the left front steering knuckle of the vehicle, and the mass of the left front wheel is known. According to Newton's second law, the first relationship function can be easily calculated.

[0053] Understandably, in some embodiments, obtaining a second relationship function of the radial vibration force of the vehicle's right front wheel in the vertical direction with respect to time by measuring includes the following steps:

[0054] A second acceleration sensor is installed at the right front steering knuckle of the vehicle, and the sixth relationship function of the acceleration of the left front wheel in the vertical direction with respect to time is obtained through the second acceleration sensor;

[0055] The product of the sixth relation function and the mass of the right front wheel is determined to be the second relation function.

[0056] In this step, it is convenient to install the second acceleration sensor at the right front steering knuckle of the vehicle, and the mass of the right front wheel is known. According to Newton's second law, the second relationship function can be easily calculated.

[0057] It is understood that in some embodiments, step S300, after determining that the tire vibration index is qualified, also includes steps S401 and S402.

[0058] Step S401: Divide the range from the preset threshold to zero into multiple continuously arranged gradient intervals, and establish multiple jitter levels that correspond one-to-one with the multiple gradient intervals.

[0059] Step S402: Determine the vibration level of the tire based on the gradient range into which the vibration index parameters fall.

[0060] In this step, the gradient interval is a range of values. By dividing the tire into multiple gradient intervals, each corresponding to a vibration level, after determining that the tire's vibration index is qualified, the tire's vibration level can be further divided to classify tires of different qualities. For example, there are four gradient intervals, ranging from a preset threshold to zero, sequentially divided into the first gradient interval, the second gradient interval, the third gradient interval, and the fourth gradient interval. These gradient intervals correspond to vibration levels D, C, B, and A, respectively. The vibration level of the tire is determined based on which gradient interval the tire's vibration index parameter falls into. From vibration level D to vibration level A, the less vibration the tire has, the higher the quality of the tire, and the less vibration the vehicle experiences. This classification of tires facilitates tire categorization and also helps control tire selling prices. In some embodiments, the width of the gradient interval is 10N to 15N, which can be understood as an empirical value.

[0061] Understandably, in some embodiments, the widths of multiple gradient intervals, ranging from a preset threshold to zero, are arranged in an increasing trend. When the vibration index parameter is below a certain level, the vehicle vibration is small and not strongly perceived by the human body. Therefore, by arranging the widths of the gradient intervals in an increasing trend, when the vibration index parameter is small, it needs to be reduced further to reach the next vibration level, thereby compensating for the weak perception of small vibrations by the human body and making the vibration level division more reasonable.

[0062] It is understood that the present invention provides a tire in which the tire vibration index is determined to be qualified by the tire vibration index evaluation method of the above embodiments, which can ensure that the vibration index parameters of the tire are qualified.

[0063] It is understood that the present invention provides a vehicle, including the tires of the above embodiments, which can reduce vehicle vibration at high speeds, improve driving experience, and ensure driving safety.

[0064] Specifically, the vehicle can be a private car, such as a sedan, SUV, MPV, or pickup truck. The vehicle can also be a commercial vehicle, such as a van, bus, small truck, or large semi-trailer. The vehicle can be a gasoline-powered vehicle or a new energy vehicle. When the vehicle is a new energy vehicle, it can be a hybrid vehicle or a pure electric vehicle.

[0065] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0066] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or their sequential relationship.

[0067] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0068] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatuses.

[0069] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.

[0070] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the couplings or direct couplings or communication connections shown or discussed may be indirect couplings or communication connections through some interfaces, apparatuses, or units, and may be electrical, mechanical, or other forms.

[0071] In this application embodiment, the terms "module" or "unit" refer to a computer program or part of a computer program that has a predetermined function and works with other related parts to achieve a predetermined goal, and can be implemented wholly or partially using software, hardware (such as processing circuitry or memory), or a combination thereof. Similarly, a processor (or multiple processors or memory) can be used to implement one or more modules or units. Furthermore, each module or unit can be part of an overall module or unit that includes the functionality of that module or unit.

[0072] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0073] The step numbers in the above method embodiments are set only for ease of explanation and do not impose any restrictions on the order of the steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

Claims

1. A method for evaluating tire vibration index, characterized in that, include: Under preset vehicle speed and preset road conditions, the first relationship function of the radial vibration force of the left front wheel of the vehicle in the vertical direction with respect to time is obtained by measurement, and the second relationship function of the radial vibration force of the right front wheel of the vehicle in the vertical direction with respect to time is obtained by measurement. The first Fourier series of the first relational function is determined as the third relational function, the first Fourier series of the second relational function is determined as the fourth relational function, and the average of the peak-to-peak value of the third relational function and the peak-to-peak value of the fourth relational function is determined as the tire vibration index parameter. A preset threshold is determined based on the preset vehicle speed and the preset road conditions; When the vibration index parameter is less than the preset threshold, the tire vibration index is deemed to be qualified. If the vibration index parameter is greater than or equal to the preset threshold, the tire vibration index is determined to be unqualified.

2. The method for evaluating tire vibration index according to claim 1, characterized in that, The method of obtaining the first relationship function of the radial vibration force of the vehicle's left front wheel in the vertical direction with respect to time by measurement includes the following steps: A first acceleration sensor is installed at the left front steering knuckle of the vehicle, and the fifth relationship function of the acceleration of the left front wheel in the vertical direction with respect to time is obtained through the first acceleration sensor; The product of the fifth relational function and the mass of the left front wheel is used as the first relational function.

3. The method for evaluating tire vibration index according to claim 1, characterized in that, The method of obtaining the second relationship function of the radial vibration force of the right front wheel of the vehicle in the vertical direction with respect to time by measurement includes the following steps: A second acceleration sensor is installed at the right front steering knuckle of the vehicle, and the sixth relationship function of the acceleration of the left front wheel in the vertical direction with respect to time is obtained through the second acceleration sensor; The product of the sixth relational function and the mass of the right front wheel is used as the second relational function.

4. The method for evaluating tire vibration index according to claim 1, characterized in that, After determining that the tire vibration index is qualified, the following steps are included: Multiple continuously arranged gradient intervals are divided from the preset threshold to zero, and multiple jitter levels are established that correspond one-to-one with the multiple gradient intervals. The vibration level of the tire is determined based on the gradient range into which the vibration index parameters fall.

5. The method for evaluating tire vibration index according to claim 4, characterized in that, The widths of the multiple gradient intervals are arranged in an increasing trend, ranging from the preset threshold to zero.

6. The method for evaluating tire vibration index according to claim 4, characterized in that, The width of the gradient interval is 10N to 15N.

7. The method for evaluating tire vibration index according to claim 1, characterized in that, The preset vehicle speed is 100km / h to 140km / h.

8. The method for evaluating tire vibration index according to claim 1, characterized in that, The preset threshold is 120N to 140N.

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