Evaluation model establishment method for tread pattern noise

Abstract

The invention provides a method for establishing an evaluation model of tread pattern noise, solves the technical problem of lack of an evaluation model for noise generated by tread pattern pitch at present, and can be widely applied to the field of tire detection. Comprising the following steps: arranging a microphone on one side of a tire driving direction, and collecting tire noise; the tire rotates for multiple times in a uniformly variable speed form, and order domain and spectrum analysis is carried out on data collected by each microphone to obtain an order spectrum and an order average spectrum; averaging the order average frequency spectrum to obtain averaged order frequency spectrum average data; taking the peak order of the order frequency spectrum noise synthesized by each microphone as a reference order, and carrying out order range division on the synthesized order frequency spectrum noise to obtain an order number corresponding to the order frequency spectrum noise; and respectively carrying out amplitude and energy correction of a window function on the noise energy of the order frequency spectrum noise of different orders to obtain a tire pattern noise evaluation model.

Description

Technical Field

[0001] The invention belongs to the technical field of tire testing, and in particular relates to a method for establishing an evaluation model of tire pattern noise. Background Art

[0002] Tire pattern noise includes pattern block pitch impact noise, vibration radiation noise caused by rolling deformation, stick-slip noise, and noise caused by resonance. Among them, tire pattern pitch noise needs to be paid special attention to, which is also one of the main components of pattern noise. In addition, through experiments, it is found that the radiation characteristics of the tire pattern noise source have obvious directionality, and the front and rear end radiation noise in the direction of tire travel is greater than the side radiation noise.

[0003] At present, the domestic and international standard evaluation indicators for tire pattern noise are all based on the overall noise. The overall noise of tire pattern includes pattern pitch noise, resonance noise, stick-sucking and stick-slip noise, etc. However, for R&D designers who develop low-noise pattern tires, the primary concern is the noise generated by the tire pattern pitch. Summary of the invention

[0004] The purpose of the present invention is to solve the deficiencies of the above-mentioned technology and to provide a method for establishing an evaluation model of tire pattern noise.

[0005] To this end, the present invention provides a method for establishing an evaluation model of tire pattern noise, comprising the following steps:

[0006] S10: placing microphones at the front end, rear end and side of the tire in the direction of travel to collect tire noise;

[0007] S20: the tire rotates multiple times in a uniformly variable speed form, and the data collected by each microphone are analyzed in the order domain and spectrum to obtain an order spectrum and an order average spectrum;

[0008] S30: performing an averaging process on the order average spectrum to obtain averaged order spectrum average data;

[0009] S40: synthesizing the averaged order spectrum average data to obtain the synthesized order spectrum noise of each microphone;

[0010] S50: taking the peak order of the order spectrum noise synthesized by each microphone as the reference order, dividing the synthesized order spectrum noise into order ranges, and obtaining the order number corresponding to the order spectrum noise;

[0011] S60: performing velocity slicing on order spectrum noises of different orders respectively, and calculating noise energy of order spectrum noises of different orders;

[0012] S70: performing window function amplitude and energy correction on noise energies of order spectrum noises of different orders respectively, and obtaining a tire pattern noise evaluation model.

[0013] The present invention provides a method for establishing an evaluation model of tire pattern noise, which has the following beneficial effects:

[0014] The present invention establishes a mathematical model of pattern pitch noise based on a bench test machine in a semi-anechoic chamber, designs a reasonable microphone layout, collects data in an order tracking manner, and tests and evaluates tire pattern noise from the perspective of order domain in combination with tire pattern pitch design parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a pattern noise evaluation model diagram of the present invention;

[0016] Figure 2 is an order spectrum average graph of the present invention;

[0017] Figure 3 It is the average comprehensive graph of order spectrum of the present invention;

[0018] Figure 4 This is a comparison diagram of the first-order speed slices of the pattern when the speed is 40 km / h;

[0019] Figure 5 is the order spectrum of each receiving point of the present invention;

[0020] Figure 6 It is a diagram of the pattern pitch noise analysis results of the present invention. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments to help understand the content of the present invention. The methods used in the present invention are all conventional methods unless otherwise specified; the raw materials and devices used are all conventional commercial products unless otherwise specified.

[0022] According to the radiation characteristics of tire pattern noise, the evaluation model of tire pattern noise is established as shown in formula (1). The microphone layout is as follows: Figure 1 As shown, the model includes four noise receiving points M1, M2, M3, and M4. The noise receiving points are respectively located at the front end, side, and rear end of the tire grounding in the driving direction, and are used for comprehensive evaluation of tire pattern noise.

[0023]

[0024] PN i ={PN uj} (2);

[0025] SN i={SN uj} (3);

[0026] ON i ={ON uj} (4);

[0027] in:

[0028] Synthetical Noise represents the comprehensive result of tire pattern noise under different speed conditions;

[0029] PN i represents the first-order noise of the pattern at the i-th receiving point;

[0030] PN u Represents the first-order noise synthesis of the pattern of multiple speeds at the i-th receiving point;

[0031] SN i represents the second-order noise of the pattern at the i-th receiving point;

[0032] SN u Represents the synthesis of the second-order noise of the pattern of multiple speeds at the i-th receiving point;

[0033] ON i Indicates other pattern noises (such as pipe column noise, pump noise, etc.) at the i-th receiving point;

[0034] ON u The pattern representing multiple velocities at the i-th receiving point is synthesized by other noises (such as column noise, pump noise, etc.).

[0035] The evaluation method provides models including ON i Noise part, but not involved in the analysis and calculation, only the noise PN generated by the tire pattern pitch is considered i and SN i .

[0036] Since the tire tread pitch noise has the characteristic of changing with the speed, and is closely related to the number and type of tire tread pitch, the tire tread pitch noise is divided into the first-order tread pitch noise and the second-order tread pitch noise. Combined with the driving scenes of vehicles on urban roads and highways, the noise radiation levels at five typical speeds of 40km / h, 60km / h, 80km / h, 100km / h and 120km / h are focused on. The test is carried out in a uniform speed reduction mode of 120km / h-40km / h. During the test, the maximum speed must be greater than 120km / h and the minimum speed must be less than 40km / h to ensure that the test can be triggered normally. Such a test needs to be repeated 3 times and the collected data is saved. After the data is obtained through the experiment, the three measurement data need to be first analyzed in the order domain and spectrum to obtain the order spectrum and the order average spectrum, and then averaged, see formula (5), to remove the influence of random errors in the test.

[0037]

[0038] in: The order spectrum data of each noise receiving point after averaging the data collected three times, The single order spectrum data of each noise receiving point, i = 1, 2, 3, 4. The averaged order spectrum example is as follows Figure 5 shown.

[0039] The average processing of the third-order spectrum average data of each noise receiving point is calculated as shown in formula (6):

[0040]

[0041] in: The spectrum average of the 3rd order spectrum average data of each noise receiving point, The average data of the single order spectrum of each noise receiving point, i = 1, 2, 3, 4. The average order spectrum of each receiving point is as follows: Figure 2 shown.

[0042] According to equation (6), the order spectra of each receiving point can be averaged. In order to make a comprehensive judgment, the average order spectrum data of each receiving point needs to be synthesized. The processing method is as follows:

[0043]

[0044]

[0045] in:

[0046] SL {band}Represents the composite order spectrum of the second receiving point and the third receiving point, unit: Pa^2;

[0047] SL avg{band} It represents the synthesized order spectrum noise of the second receiving point and the third receiving point, unit: dB;

[0048] SF {band} Represents the composite order spectrum of the first receiving point and the fourth receiving point, unit: Pa^2;

[0049] SF avg{band} It represents the synthesized order spectrum noise of the first receiving point and the fourth receiving point, unit: dB;

[0050] SS {band} Indicates the synthesized order spectrum noise of each receiving point, unit: dB.

[0051] An example of the average comprehensive order spectrum of each receiving point is as follows: Figure 3 shown.

[0052] In order to disperse the tire pattern noise energy, the tire pattern pitch is usually designed with multiple pitches, and the number and pitch length of each pitch are different. In addition, the tire is affected by factors such as the road surface and pitch arrangement during actual driving, and the order corresponding to the maximum value of the tire pattern pitch noise is not necessarily the total number of designed pattern pitches. Therefore, it is necessary to use the order corresponding to the peak value generated during actual driving of the tire as the reference order. The purpose of obtaining the order average spectrum is to determine the peak order of the tire pattern pitch noise during driving. Peak , with O Peak The first and second order ranges of tire pattern noise are divided for the reference order. The principles of division are as follows:

[0053]

[0054] in:

[0055] O 1{up / low} Indicates the order corresponding to the upper and lower limits of the first-order width of the pattern.

[0056] O 2{up / low} Indicates the order corresponding to the upper and lower limits of the second-order width of the pattern.

[0057] m, n represent the order width factors, m=0.25, n=0.375.

[0058] Through equations (12) and (13), we can calculate the orders corresponding to the upper and lower limits of the width of the first and second order of pattern noise, as shown in Table 1.

[0059] Table 1

[0060] Total_Max,dB <![CDATA[O peak ]]> m n 83.21 72 0.25 0.375 POS_Max <![CDATA[O 1{low} ]]> <![CDATA[O 2{low} ]]> 580 54 90 <![CDATA[O 1{up} ]]> <![CDATA[O 2{up} ]]> 90 198

[0061] Then, the average order spectrum of each receiving point is sliced ​​to obtain five typical speed slices (40 / 60 / 80 / 100 / 120km / h). Then, the first-order and second-order noise energy of the pattern at each typical speed is calculated according to the range of the order, such as Figure 4 As shown in the figure, the calculation method of the first-order and second-order noise energy of the pattern of a single speed is as follows:

[0062] The spectrum function format is Auto-power Linear (linear self-power spectrum):

[0063]

[0064]

[0065] in:

[0066] It refers to the velocity slice spectrum at the 4 receiving points. The unit is Pa. i represents the receiving point number and its value is 1, 2, 3, 4. u represents the typical speed and its value is 40, 60, 80, 100, 120.

[0067] A j{band} It refers to the square sum of the sound pressures corresponding to the velocity slice spectra of each receiving point on the tire side, unit: Pa^2, j represents the order of the pattern pitch noise, and the value is 1 or 2.

[0068] A javg{band} It refers to the synthetic noise of the tire side velocity slice spectrum, unit: dB, j represents the pattern pitch noise order, the value is 1 or 2.

[0069] B j{band} It refers to the square sum of the sound pressures corresponding to the velocity slice spectra of each receiving point at the front and rear ends of the tire in the driving direction. The unit is Pa^2. j represents the order of the pattern pitch noise, which is 1 or 2.

[0070] B javg{band} It refers to the synthetic noise of the speed slice spectrum of the front and rear ends of the tire in the driving direction. The unit is dB. j represents the order of the pattern pitch noise and the value is 1 or 2.

[0071] C j{band} It refers to the square of the sound pressure of the synthetic noise of the speed slice spectrum at each receiving point of the tire, unit: Pa^2, j represents the order of the pattern pitch noise, and the value is 1 or 2.

[0072] D j{band}It refers to the effective value (rms) of the synthetic noise spectrum of the velocity slice spectrum of each receiving point, unit: Pa, j represents the order of pattern pitch noise, the value is 1 or 2, N is the upper and lower limit width of the pattern 1st order or 2nd order.

[0073] E j{band} Refers to D j{band} The amplitude and energy of the window function are corrected for the spectrum data. The unit is Pa. δ represents the window energy correction factor, τ represents the window amplitude correction factor. Usually we add a Hanning window, δ=1.63, τ=2, j represents the order of the pattern pitch noise, and the value is 1 or 2.

[0074] SPL j{band} It refers to the radiation energy of the j-th order noise of the pattern, unit: dB, j represents the order of the pattern pitch noise, and the value is 1 or 2.

[0075] SPL j{band} It refers to the radiation energy of the j-th order noise of the pattern, unit: dB, j represents the order of the pattern pitch noise, and the value is 1 or 2.

[0076] Evaluation index calculation:

[0077] Primary Noise=SPL 1{band} (twenty two);

[0078] Secondary Noise=SPL 2{band} (twenty three);

[0079] From equations (4) and (6), we get:

[0080]

[0081]

[0082] H j{band} =G j{band} *δ / τ (27);

[0083] Synthetical Noise j{band} =20*lg(H j{band} / P ref ) (28);

[0084] in:

[0085] Primary Noise refers to the first-order noise of the tire tread pitch.

[0086] Secondary Noise refers to the second-order noise of the tire tread pitch.

[0087] F{band} It refers to the comprehensive sound pressure square of tire pattern noise in the speed range of 120km / h-40km / h, unit: Pa^2.

[0088] G j{band} It refers to the average effective value of the j-th order spectrum of the tire pattern in the speed range of 120km / h-40km / h, unit: Pa.

[0089] H j{band} Refers to the window function amplitude and energy correction of the average effective value of the j-order spectrum of the tire pattern in the speed range of 120km / h-40km / h, unit: Pa. δ represents the window energy correction factor, τ represents the window amplitude correction factor, usually we add a Hanning window, δ=1.63, τ=2, j represents the pattern pitch noise order, the value is 1 or 2.

[0090] Synthetical Noise j{ band } It refers to the j-th order noise of the tire pattern in the speed range of 120km / h-40km / h, unit: dB.

[0091] The schematic diagram of data processing results is shown in the following table: Figure 6 And as shown in Table 2.

[0092] Table 2

[0093]

[0094] However, what is described above is only a specific embodiment of the present invention and should not be used to limit the scope of implementation of the present invention. Therefore, the replacement of equivalent components, or equivalent changes and modifications made according to the scope of protection of the present invention should still fall within the scope covered by the claims of the present invention.

Claims

1. A method for establishing a tire pattern noise evaluation model, characterized in that: The following steps are involved: S10: placing microphones at the front end, rear end and side of the tire in the direction of travel to collect tire noise; S20: the tire rotates multiple times in a uniformly variable speed form, and the data collected by each microphone are analyzed in the order domain and spectrum to obtain an order spectrum and an order average spectrum; S30: performing an averaging process on the order average spectrum to obtain averaged order spectrum average data; S40: synthesizing the averaged order spectrum average data to obtain the synthesized order spectrum noise of each microphone; S50: taking the peak order of the order spectrum noise synthesized by each microphone as the reference order, dividing the synthesized order spectrum noise into order ranges, and obtaining the order number corresponding to the order spectrum noise; S60: performing velocity slicing on order spectrum noises of different orders respectively, and calculating noise energy of order spectrum noises of different orders; S70: performing window function amplitude and energy correction on noise energies of order spectrum noises of different orders respectively, and obtaining a tire pattern noise evaluation model.

2. The method for establishing a tire pattern noise evaluation model according to claim 1, characterized in that: The specific steps of rotating the tire multiple times in a uniformly variable speed form are: The tire rotates three times in a uniformly decelerated form, wherein the initial speed of the tire rotation is greater than the tire rotation speed when the vehicle is traveling at a speed of 120 kilometers per hour, and the final speed of the tire rotation is less than the tire rotation speed when the vehicle is traveling at a speed of 40 kilometers per hour.

3. The method for establishing a tire pattern noise evaluation model according to claim 2, characterized in that: The data collected by each microphone is analyzed in order domain and spectrum. The calculation steps to obtain the order spectrum and the order average spectrum are as follows: in, It represents the order spectrum data of each noise receiving point after averaging the data collected three times. Represents the single-order spectrum data of each noise receiving point, i=1, 2, 3, 4.

4. The method for establishing a tire pattern noise evaluation model according to claim 3, characterized in that: The averaged order spectrum average data is synthesized to obtain the order spectrum noise synthesized by each microphone in the following calculation steps: in, It represents the spectrum average of the third-order spectrum average data of each noise receiving point. Represents the single-order spectrum average data of each noise receiving point, i=1, 2, 3, 4.

5. The method for establishing a tire pattern noise evaluation model according to claim 1, characterized in that: The averaged order spectrum average data is synthesized to obtain the order spectrum noise synthesized by each microphone in the following calculation steps: Among them, SL {band} Indicates the synthesized order spectrum of the second receiving point and the third receiving point; SL avg{band} It represents the synthesized order spectrum noise of the second receiving point and the third receiving point; SF {band} Indicates the synthesized order spectrum of the first receiving point and the fourth receiving point; SF avg{band} It represents the synthesized order spectrum noise of the first receiving point and the fourth receiving point; SS {band} Represents the synthesized order spectrum noise of each receiving point.

6. The method for establishing a tire pattern noise evaluation model according to claim 5, characterized in that: The peak order of the order spectrum noise synthesized by each microphone is used as the reference order, and the synthesized order spectrum noise is divided into order ranges to obtain the order number corresponding to the order spectrum noise. The specific steps are as follows: SS {band} The peak order is taken as the reference order O Peak , with O Peak Divide the first and second order ranges of tire noise into reference orders; Among them, O 1{up / low} Indicates the order corresponding to the upper and lower limits of the first-order width of the noise; O 2{up / low} Indicates the order corresponding to the upper and lower limits of the second-order width of the noise; m, n represent the order width factors, m = 0.25, n = 0.

375.

7. The method for establishing a tire pattern noise evaluation model according to claim 6, characterized in that: The specific steps of performing velocity slicing on order spectrum noises of different orders and calculating the noise energy of order spectrum noises of different orders are as follows: Get slices of five typical speeds, and then calculate the first-order and second-order noise energy of the pattern at each typical speed according to the range of the order; in, Refers to the velocity slice spectrum of the 4 receiving point positions, i represents the receiving point number, and its value is 1, 2, 3, 4, u represents the typical speed, and its value is 40, 60, 80, 100, 120; A j{band} It refers to the square sum of the sound pressure corresponding to the velocity slice spectrum of each receiving point on the side of the tire. j represents the order of the pattern pitch noise, which takes a value of 1 or 2. A javg{band} It refers to the synthetic noise of the tire side velocity slice spectrum, j represents the order of the pattern pitch noise, and the value is 1 or 2; B j{band} It refers to the square sum of the sound pressures corresponding to the velocity slice spectra of each receiving point at the front and rear ends of the tire in the driving direction. j represents the order of the pattern pitch noise, which takes a value of 1 or 2. B javg{band} It refers to the synthetic noise of the spectrum of the speed slices of the front and rear ends of the tire in the driving direction. j represents the order of the pattern pitch noise, which takes a value of 1 or 2. C j{band} It refers to the square of the sound pressure of the synthetic noise of the speed slice spectrum at each receiving point of the tire. j represents the order of the pattern pitch noise, which takes a value of 1 or 2. D j{band} It refers to the effective value of the synthetic noise spectrum of the velocity slice spectrum of each receiving point, j represents the order of the pattern pitch noise, which takes a value of 1 or 2, and N is the upper and lower limit width of the pattern 1st order or 2nd order.

8. The method for establishing a tire pattern noise evaluation model according to claim 7, characterized in that: The calculation steps for the amplitude and energy correction of the window function for the noise energy of the order spectrum noise of different orders are as follows: E j{band} =D j{band} *d / t; SPL j{band} =20*lg(E j{band} / P ref ); Among them, E j{band} Refers to D j{band} The spectrum data of the window function is corrected for amplitude and energy, δ represents the windowed energy correction factor, τ represents the windowed amplitude correction factor, δ=1.63, τ=2, j represents the pattern pitch noise order, and the value is 1 or 2; SPL j{band} It refers to the radiation energy of the j-th order noise of the pattern, where j represents the order of the pattern pitch noise and takes a value of 1 or 2.

Images