Intelligent monitoring method for preparation of porous sound-absorbing blanket

Abstract

The invention relates to the technical field of sound-absorbing blanket preparation, in particular to an intelligent monitoring method for porous sound-absorbing blanket preparation, which comprises the following steps: determining uniform characterization parameters of a shaped product based on periodically acquired sound-absorbing coefficients of each detection block under different noise frequencies; determining whether the preparation of the shaped product is qualified or not on the basis of the sound absorption uniformity characterization parameter, when the preparation of the shaped product is determined to be abnormal, determining a pressure change parameter aiming at the composite product on the basis of the reaction force of the composite product on the needling in the needling trepanning process, and adjusting the preparation parameter of the shaped product on the basis of the pressure change parameter; the sound absorption uniformity of all the areas of the porous sound absorption blanket is monitored, the preparation parameters are flexibly adjusted according to the determined sound absorption uniformity condition of all the areas of the product, and the preparation efficiency of the porous sound absorption blanket is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of sound-absorbing blanket preparation, and in particular to an intelligent monitoring method for preparing porous sound-absorbing blankets. Background Art

[0002] With the rapid development of the automotive industry, people's demands for cars are not only beautiful exteriors, but also have high requirements for interior comfort, functionality, and noise resistance. During the driving process, various noises will be transmitted into the car cabin, causing noise pollution to the driver and passengers. Therefore, interior sound-absorbing blankets are generally installed on the body sheet metal inside the car cabin to provide sound insulation.

[0003] Chinese patent document CN201510447611.5 discloses a manufacturing process for a highly sound-absorbing automotive carpet. The carpet comprises a top PET layer, polyester fiber, a middle PET layer, and a back PE layer, which are laminated together from top to bottom. The finished carpet undergoes secondary shaping. This technical solution suffers from the following problems: It fails to consider monitoring the sound absorption uniformity of each area of ​​the porous sound-absorbing carpet, making it impossible to flexibly adjust the production parameters based on the determined sound absorption uniformity of each area of ​​the product, thereby affecting the production efficiency of the porous sound-absorbing carpet. Summary of the Invention

[0004] To this end, the present invention provides an intelligent monitoring method for the preparation of porous sound-absorbing blankets, which overcomes the problem in the prior art that the sound absorption uniformity of each area of ​​the porous sound-absorbing blanket is not monitored, resulting in an inability to flexibly adjust preparation parameters based on the determined sound absorption uniformity of each area of ​​the product, thereby affecting the preparation efficiency of the porous sound-absorbing blanket.

[0005] To achieve the above objectives, the present invention provides an intelligent monitoring method for preparing a porous sound-absorbing blanket, comprising:

[0006] S1, performing a needle punching treatment on the first raw material to form a surface layer;

[0007] S2, needle punching the second raw material to form a bottom felt layer;

[0008] S3, laminating the middle layer on one side of the surface layer, and laminating the bottom felt layer on one side of the middle layer to produce a composite product;

[0009] S4, performing a needle punching process on the composite product to complete the hole punching process on the composite product;

[0010] S5, heating the product after opening to obtain a finalized product;

[0011] S6, determining the periodically obtained finalized product as a test product, dividing the test product into a plurality of test blocks, and determining a uniform characterization parameter of the finalized product based on the sound absorption coefficient of each test block at different noise frequencies;

[0012] S7, determining whether the preparation of the finalized product is qualified based on the sound absorption uniformity characterization parameters, including:

[0013] When it is determined that there is an abnormality in the preparation of the shaped product, a pressure change parameter for the composite product is determined based on the reaction force of the composite product to the needling during the needling process, and the preparation parameters of the shaped product are adjusted based on the pressure change parameter, including adjusting the needling frequency in the process of generating the base felt to a corresponding value, adjusting the needling depth in the hole opening process to a corresponding value, and adjusting the needling frequency in the hole opening process to a corresponding value;

[0014] Alternatively, when it is determined that the preparation of the finalized product is qualified, the current preparation parameters are continuously used to complete the preparation of the finalized product.

[0015] Furthermore, in S6, the process of determining the uniform characterization parameters of the finalized product based on the sound absorption coefficient of each detection block at different noise frequencies includes:

[0016] Calculate the variance of each sound absorption coefficient of each detection block at a single noise frequency to obtain the sound absorption difference for the single noise frequency;

[0017] Calculate the average value of each sound absorption difference corresponding to each noise frequency to obtain the uniformity characterization parameter;

[0018] In said S7, the process of determining whether the preparation of the finalized product is qualified based on the sound absorption uniformity characterization parameter includes:

[0019] When the sound absorption uniformity characterization parameter is less than or equal to the first preset sound absorption uniformity characterization parameter, it is determined that the preparation of the finalized product is qualified, and the current preparation parameters are continuously used to complete the preparation of the finalized product;

[0020] When the sound absorption uniformity characterization parameter is less than or equal to the second preset sound absorption uniformity characterization parameter and greater than the first preset sound absorption uniformity characterization parameter, determining whether the preparation of the finalized product is qualified in combination with the comprehensive sound absorption difference value;

[0021] When the sound absorption uniformity characterization parameter is greater than the second preset sound absorption uniformity characterization parameter, it is determined that the preparation of the shaped product is abnormal, and the pressure change parameter for the composite product is determined based on the reaction force of the composite product to the needle punching during the needle punching process, and the preparation parameters of the shaped product are adjusted based on the pressure change parameter.

[0022] Furthermore, the process of determining whether the preparation of the finalized product is qualified in combination with the comprehensive sound absorption difference value includes:

[0023] Calculate the variance of each sound absorption difference corresponding to each noise frequency to obtain the comprehensive sound absorption difference value;

[0024] If the comprehensive sound absorption difference value is less than or equal to the preset comprehensive sound absorption difference value, the number of divisions of the inspection product will be adjusted to the corresponding value based on the comprehensive sound absorption difference value;

[0025] If the comprehensive sound absorption difference value is greater than the preset comprehensive sound absorption difference value, it is determined that the preparation of the shaped product is abnormal. Based on the reaction force of the composite product to the needle punching during the needle punching process, the pressure change parameters for the composite product are determined, and the preparation parameters of the shaped product are adjusted based on the pressure change parameters.

[0026] Furthermore, the number of divisions for the inspection product is adjusted to a corresponding value based on the comprehensive sound absorption difference value, wherein:

[0027] The increase in the number of segments is inversely proportional to the overall sound absorption difference.

[0028] Furthermore, the process of determining the pressure change parameter for the composite product based on the reaction force of the composite product to the needling during the needling process includes:

[0029] Based on the reaction force of the composite product to acupuncture obtained at each time node, a time domain curve of the reaction force is drawn;

[0030] The difference between the maximum and minimum values ​​in the reaction force time domain curve is solved to obtain the pressure change parameter.

[0031] Furthermore, the process of adjusting the preparation parameters of the shaped product based on the pressure change parameter includes:

[0032] If the pressure variation parameter is less than or equal to the preset pressure variation parameter, adjusting the preparation parameters of the finalized product based on the difference in sound absorption of each noise frequency;

[0033] If the pressure change parameter is greater than the preset pressure change parameter, the needling frequency of the second raw material in the process of generating the bottom felt layer is adjusted to a corresponding value based on the pressure change parameter.

[0034] Furthermore, the needling frequency of the second raw material during the production of the bottom felt layer is adjusted to a corresponding value based on the pressure change parameter, wherein:

[0035] The increase in the frequency of needling the second raw material is positively correlated with the pressure change parameter.

[0036] Furthermore, the process of adjusting the preparation parameters of the finalized product based on the difference in sound absorption of each noise frequency includes:

[0037] The noise frequency corresponding to the maximum value of each sound absorption difference is determined as the abnormal frequency;

[0038] If the abnormal frequency is high-frequency noise or medium-frequency noise, the frequency of the needle punching during the hole punching process is adjusted to the corresponding value based on the sound absorption uniformity characterization parameter;

[0039] If the abnormal frequency is low-frequency noise, the needle-punch perforation depth during the perforation treatment is adjusted to a corresponding value based on the sound absorption difference of the abnormal frequency.

[0040] Furthermore, the frequency of the acupuncture holes in the hole processing process is adjusted to a corresponding value based on the sound absorption uniformity characterization parameter, wherein,

[0041] The reduction in the frequency of needle punching is proportional to the sound absorption uniformity characterization parameter.

[0042] Furthermore, the depth of the needle punching holes in the hole processing process is adjusted to a corresponding value based on the difference in sound absorption of the abnormal frequency, wherein,

[0043] The increase in the depth of the needle holes during the hole treatment is proportional to the difference in sound absorption at abnormal frequencies.

[0044] Compared with the prior art, the present invention has the advantages of determining uniformity characterization parameters of a finalized product based on periodically obtaining the sound absorption coefficient of each detection block at different noise frequencies; determining whether the preparation of the finalized product is qualified based on the sound absorption uniformity characterization parameters; when it is determined that the preparation of the finalized product is abnormal, determining pressure change parameters for the composite product based on the reaction force of the composite product to the needling during the needling process; and adjusting the preparation parameters of the finalized product based on the pressure change parameters, including adjusting the needling frequency in the process of generating the base felt to a corresponding value, adjusting the needling depth in the needling process to a corresponding value, and adjusting the needling frequency in the needling process to a corresponding value; monitoring the sound absorption uniformity of each area of ​​the porous sound-absorbing blanket, and flexibly adjusting the preparation parameters according to the determined sound absorption uniformity of each area of ​​the product, thereby improving the preparation efficiency of the porous sound-absorbing blanket.

[0045] Furthermore, the acceptance of the finalized product's production is determined based on the sound absorption uniformity parameter. The sound absorption differential is calculated. This differential represents the differences between each test block at a corresponding noise frequency. This differential determines the sound absorption differential of the sound-absorbing blanket at a single noise frequency. The lower the differential, the more uniform the absorption of each test block at that noise frequency. Vehicles experience noise of various frequencies during driving. A uniformity parameter is determined. This parameter characterizes the sound absorption performance of the finalized product at different frequencies. A lower uniformity parameter indicates better absorption of various noises in actual use. When the sound absorption uniformity parameter is less than or equal to the first preset sound absorption uniformity parameter, the sound absorption capacity of the finalized product is minimally different between each test block, indicating stable product quality. In this case, the finalized product is deemed qualified and the current production parameters are maintained. When the sound absorption uniformity parameter is less than or equal to the second preset sound absorption uniformity parameter and greater than the first preset sound absorption uniformity parameter, the product's sound absorption uniformity fluctuates. Further assessment is conducted based on the comprehensive sound absorption difference value, which represents the degree of dispersion in sound absorption differences at each noise frequency. This value determines whether the sound absorption at each noise frequency exhibits slight anomalies, or whether significant differences exist between test blocks at a single noise frequency, leading to an inflated sound absorption uniformity value. When the comprehensive sound absorption difference value is less than or equal to the preset comprehensive sound absorption difference value, the product's sound absorption performance at different noise frequencies is relatively consistent, and the differences in sound absorption at each noise frequency are relatively stable. In this case, insufficient testing accuracy may prevent the product from being accurately identified as anomaly. In this case, the number of test samples segmented should be adjusted to further optimize testing accuracy. When the comprehensive sound absorption difference value is greater than the preset comprehensive sound absorption difference value, the product's sound absorption at different noise frequencies exhibits significant variability, indicating a manufacturing anomaly. In this case, a pressure change parameter for the composite product is determined based on the composite product's reaction force to the needle punch during the perforation process, and the preparation parameters for the finalized product are adjusted based on the pressure change parameter. By determining uniformity characterization parameters, we quantify the sound absorption performance of the finalized product at different noise frequencies. If any abnormalities are detected in the finalized product, we can promptly adjust the production parameters to ensure optimal absorption across all noise frequencies. This allows us to promptly identify production process issues and ensure consistent product quality. When production is identified, we can adjust the production parameters promptly, improving the sound absorption quality of the finalized product while further increasing the production efficiency of the porous sound-absorbing blanket.

[0046] Furthermore, the preparation parameters of the finalized product are adjusted based on the pressure variation parameter. The pressure variation parameter characterizes the fluctuation of the composite product's reaction force to needling during the needling process. The composite product's reaction force to needling reflects the resistance of the material's internal microstructure. The variation in reaction force is related to the degree of fiber entanglement within the material. The pressure variation parameter is obtained by plotting the reaction force time-domain curve and calculating the difference between the maximum and minimum values. This parameter reflects the dynamic changes in the material's microstructure during the needling process. When the pressure variation parameter is greater than the preset pressure variation parameter, the reaction force fluctuates significantly. This is due to excessively tight or loose fiber entanglement in the base felt layer, causing the material's internal microstructure to change dramatically during the needling process. In this case, due to the unevenness of the base felt layer and local density differences, sound waves encounter the uneven structure during propagation, resulting in reflection and refraction, which prevents effective absorption and attenuation. This in turn affects the overall noise absorption, resulting in some areas having better absorption and others having poorer absorption, resulting in less stable and comprehensive noise absorption. Increasing the needling frequency in this case allows the fibers to be more tightly intertwined during the needling process, improving the uniformity of the base felt. When the pressure variation parameter is less than or equal to the preset pressure variation parameter, the manufacturing parameters of the finalized product are adjusted based on the sound absorption differences at each noise frequency. The noise frequency corresponding to the maximum sound absorption difference is identified as the abnormal frequency, as the sound absorption difference is greatest at this frequency, indicating that the product's sound absorption performance is unstable at this frequency. When the abnormal frequency is high-frequency or medium-frequency noise, the high needling frequency and overly dense pores compromise the integrity of the sound-absorbing structure, reducing the reflection and scattering of medium- and high-frequency sound waves between fibers and lowering the absorption capacity for medium- and high-frequency noise. Adjusting the needling frequency to alter the number of pores on the material surface improves high- and medium-frequency sound absorption. When the abnormal frequency is low-frequency noise, the insufficient needling amplitude and small pore diameter make it difficult for low-frequency sound waves to enter the pores, where they dissipate energy, resulting in suboptimal absorption of low-frequency noise. In this case, the needling depth during the pore-forming process is adjusted to the corresponding value, increasing the pore diameter to facilitate the transmission and absorption of low-frequency noise. Monitoring changes in the product's mechanical properties during the needling process reflects the uniformity and stability of the product's internal structure, providing data support for product anomalies. When a finalized product exhibits anomalies, the needling frequency and hole depth are adjusted to optimize the product's structure and performance, improving its sound absorption performance and making it more suitable for different acoustic environments. This also enhances the product's structural stability and further improves the efficiency of preparing porous sound-absorbing blankets. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a flowchart of the steps of an intelligent monitoring method for preparing a porous sound-absorbing blanket according to an embodiment of the present invention;

[0048] Figure 2This is a logic decision diagram for determining whether the preparation of a finalized product is qualified based on the sound absorption uniformity characterization parameter according to an embodiment of the present invention. DETAILED DESCRIPTION

[0049] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention.

[0050] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0051] See also Figure 1 as well as Figure 2 , which are respectively a flowchart of the steps of an intelligent monitoring method for preparing a porous sound-absorbing blanket according to an embodiment of the present invention and a logic determination diagram for determining whether the preparation of a finalized product is qualified based on sound absorption uniformity characterization parameters; an intelligent monitoring method for preparing a porous sound-absorbing blanket according to an embodiment of the present invention comprises:

[0052] S1, performing a needle punching treatment on the first raw material to form a surface layer;

[0053] S2, needle punching the second raw material to form a bottom felt layer;

[0054] S3, laminating the middle layer on one side of the surface layer, and laminating the bottom felt layer on one side of the middle layer to produce a composite product;

[0055] S4, performing a needle punching process on the composite product to complete the hole punching process on the composite product;

[0056] S5, heating the product after opening to obtain a finalized product;

[0057] S6, determining the periodically obtained finalized product as a test product, dividing the test product into a plurality of test blocks, and determining a uniform characterization parameter of the finalized product based on the sound absorption coefficient of each test block at different noise frequencies;

[0058] S7, determining whether the preparation of the finalized product is qualified based on the sound absorption uniformity characterization parameters, including:

[0059] When it is determined that there is an abnormality in the preparation of the shaped product, a pressure change parameter for the composite product is determined based on the reaction force of the composite product to the needling during the needling process, and the preparation parameters of the shaped product are adjusted based on the pressure change parameter, including adjusting the needling frequency in the process of generating the base felt to a corresponding value, adjusting the needling depth in the hole opening process to a corresponding value, and adjusting the needling frequency in the hole opening process to a corresponding value;

[0060] Alternatively, when it is determined that the preparation of the finalized product is qualified, the current preparation parameters are continuously used to complete the preparation of the finalized product.

[0061] Specifically, the surface layer is non-woven fabric with a gram weight of 200g / m2; the bottom felt layer has a gram weight of 750g / m2; and the middle layer is a PE film with a gram weight of 50g / m2.

[0062] Specifically, the specific material of the second raw material is not limited and can be a fiber material, which will not be described in detail.

[0063] Specifically, in S6, the specific method of determining the sound absorption coefficient of each detection block at different noise frequencies is not limited. The detection block can be placed in a standing wave tube to measure the sound absorption coefficient of the detection block at different frequencies. This is an existing technology and will not be described in detail.

[0064] Specifically, the noise frequencies used to determine the sound absorption coefficient include high-frequency noise, medium-frequency noise, and low-frequency noise. The specific frequencies of the high-frequency noise, medium-frequency noise, and low-frequency noise are not limited. In this example, preferably, the high-frequency noise is 3000 Hz, the medium-frequency noise is 1000 Hz, and the low-frequency noise is 100 Hz.

[0065] Specifically, the uniform characterization parameters of the finalized product are determined based on the periodic acquisition of the sound absorption coefficient of each detection block at different noise frequencies; whether the preparation of the finalized product is qualified is determined based on the sound absorption uniform characterization parameters; when it is determined that the preparation of the finalized product is abnormal, the pressure change parameters for the composite product are determined based on the reaction force of the composite product to the needling during the needling process; the preparation parameters of the finalized product are adjusted based on the pressure change parameters, including adjusting the needling frequency in the process of generating the base felt to a corresponding value, adjusting the needling depth in the needling process to a corresponding value, and adjusting the needling frequency in the needling process to a corresponding value; the sound absorption uniformity of each area of ​​the porous sound-absorbing blanket is monitored, and the preparation parameters are flexibly adjusted according to the determined sound absorption uniformity of each area of ​​the product, thereby improving the preparation efficiency of the porous sound-absorbing blanket.

[0066] Specifically, in S6, the process of determining the uniform characterization parameters of the finalized product based on the sound absorption coefficients of each detection block at different noise frequencies includes:

[0067] Calculate the variance of each sound absorption coefficient of each detection block at a single noise frequency to obtain the sound absorption difference for the single noise frequency;

[0068] Calculate the average value of each sound absorption difference corresponding to each noise frequency to obtain the uniformity characterization parameter;

[0069] In said S7, the process of determining whether the preparation of the finalized product is qualified based on the sound absorption uniformity characterization parameter includes:

[0070] When the sound absorption uniformity characterization parameter is less than or equal to the first preset sound absorption uniformity characterization parameter, it is determined that the preparation of the finalized product is qualified, and the current preparation parameters are continuously used to complete the preparation of the finalized product;

[0071] When the sound absorption uniformity characterization parameter is less than or equal to the second preset sound absorption uniformity characterization parameter and greater than the first preset sound absorption uniformity characterization parameter, determining whether the preparation of the finalized product is qualified in combination with the comprehensive sound absorption difference value;

[0072] When the sound absorption uniformity characterization parameter is greater than the second preset sound absorption uniformity characterization parameter, it is determined that the preparation of the shaped product is abnormal, and the pressure change parameter for the composite product is determined based on the reaction force of the composite product to the needle punching during the needle punching process, and the preparation parameters of the shaped product are adjusted based on the pressure change parameter.

[0073] Specifically, the first preset sound absorption uniformity characterization parameter J1 is selected within the interval [0.03, 0.04], and the second preset sound absorption uniformity characterization parameter J2 is selected within the interval [0.06, 0.09].

[0074] Specifically, the process of determining whether the preparation of the finalized product is qualified based on the comprehensive sound absorption difference value includes:

[0075] Calculate the variance of each sound absorption difference corresponding to each noise frequency to obtain the comprehensive sound absorption difference value;

[0076] If the comprehensive sound absorption difference value is less than or equal to the preset comprehensive sound absorption difference value, the number of divisions of the inspection product will be adjusted to the corresponding value based on the comprehensive sound absorption difference value;

[0077] If the comprehensive sound absorption difference value is greater than the preset comprehensive sound absorption difference value, it is determined that the preparation of the shaped product is abnormal. Based on the reaction force of the composite product to the needle punching during the needle punching process, the pressure change parameters for the composite product are determined, and the preparation parameters of the shaped product are adjusted based on the pressure change parameters.

[0078] Specifically, the preset comprehensive sound absorption difference value Z0 is selected within the interval [0.005, 0.015].

[0079] Specifically, the sound absorption uniformity parameter is used to determine the qualified preparation of the finalized product. The sound absorption differential is calculated. The sound absorption differential represents the differences between each test block at a corresponding noise frequency. By determining the sound absorption differential, the sound absorption differential of the sound-absorbing blanket at a single noise frequency is determined. The lower the sound absorption differential, the more uniform the absorption effect of each test block at that noise frequency. Vehicles are subject to noise of various frequencies during driving. A uniformity parameter is determined. The uniformity parameter characterizes the sound absorption performance of the finalized product at different frequencies. The lower the uniformity parameter, the better the material's absorption of various noises in actual applications. When the sound absorption uniformity parameter is less than or equal to the first preset sound absorption uniformity parameter, the sound absorption capacity of the finalized product among each test block is minimal, indicating stable product quality. In this case, the finalized product is determined qualified and the current preparation parameters are continued. When the sound absorption uniformity parameter is less than or equal to the second preset sound absorption uniformity parameter and greater than the first preset sound absorption uniformity parameter, the product's sound absorption uniformity fluctuates. Further assessment is conducted based on the comprehensive sound absorption difference value, which represents the degree of dispersion in sound absorption differences at each noise frequency. This value determines whether the sound absorption at each noise frequency exhibits slight anomalies, or whether significant differences exist between test blocks at a single noise frequency, leading to an inflated sound absorption uniformity value. When the comprehensive sound absorption difference value is less than or equal to the preset comprehensive sound absorption difference value, the product's sound absorption performance at different noise frequencies is relatively consistent, and the differences in sound absorption at each noise frequency are relatively stable. In this case, insufficient testing accuracy may prevent the product from being accurately identified as anomaly. In this case, the number of test samples segmented should be adjusted to further optimize testing accuracy. When the comprehensive sound absorption difference value is greater than the preset comprehensive sound absorption difference value, the product's sound absorption at different noise frequencies exhibits significant variability, indicating a manufacturing anomaly. In this case, a pressure change parameter for the composite product is determined based on the composite product's reaction force to the needle punch during the perforation process, and the preparation parameters for the finalized product are adjusted based on the pressure change parameter. By determining uniformity characterization parameters, we quantify the sound absorption performance of the finalized product at different noise frequencies. If any abnormalities are detected in the finalized product, we can promptly adjust the production parameters to ensure optimal absorption across all noise frequencies. This allows us to promptly identify production process issues and ensure consistent product quality. When production is identified, we can adjust the production parameters promptly, improving the sound absorption quality of the finalized product while further increasing the production efficiency of the porous sound-absorbing blanket.

[0080] Specifically, the number of segments to be segmented for the inspection object is adjusted to a corresponding value based on the comprehensive sound absorption difference value, wherein:

[0081] The increase in the number of segments is inversely proportional to the overall sound absorption difference.

[0082] In this embodiment, optionally,

[0083] comparing the comprehensive sound absorption difference value with a first preset comprehensive sound absorption comparison threshold and a second preset comprehensive sound absorption comparison threshold;

[0084] If the comprehensive sound absorption difference value is less than or equal to the first preset comprehensive sound absorption comparison threshold, the number of divisions of the inspection object is adjusted to 1.3 times the initial number of divisions;

[0085] If the comprehensive sound absorption difference value is less than or equal to the second preset comprehensive sound absorption comparison threshold and greater than the first preset comprehensive sound absorption comparison threshold, the number of divisions of the inspection product is adjusted to 1.2 times the initial number of divisions;

[0086] If the comprehensive sound absorption difference value is greater than the second preset comprehensive sound absorption comparison threshold, the number of divisions of the test piece is adjusted to 1.1 times the initial number of divisions;

[0087] The first preset comprehensive sound absorption comparison threshold is 0.4Z0, and the second preset comprehensive sound absorption comparison threshold is 0.7Z0.

[0088] Specifically, the number of divisions of the test object is the number of detection blocks obtained by dividing the test object in S6.

[0089] Specifically, after the adjustment of the number of segments is completed, the adjusted number of segments is compared with the preset maximum number of segments; when the adjusted number of segments is less than or equal to the preset maximum number of segments, a number of detection blocks are re-acquired according to the number of segments, and whether the preparation of the finalized product is qualified is determined based on the re-acquired sound absorption uniformity characterization parameters;

[0090] When the adjusted number of segmentations is greater than the preset maximum number of segmentations, the preset maximum number of segmentations is used as a basis for obtaining the detection block; and the first preset sound absorption uniformity characterization parameter is adjusted to a corresponding value.

[0091] When the adjustment of the first preset sound absorption uniformity characterization parameter is completed, the process of re-determining whether the preparation of the finalized product is qualified is performed based on the sound absorption uniformity characterization parameter, and when the sound absorption uniformity characterization parameter is greater than the adjusted second preset sound absorption uniformity characterization parameter, it is determined that the preparation of the finalized product is abnormal, based on the reaction force of the composite product to the needle punching during the needle punching process, the pressure change parameter for the composite product is determined, and the preparation parameter of the finalized product is adjusted based on the pressure change parameter.

[0092] In this embodiment, optionally, the first preset sound absorption uniformity characterization parameter is adjusted to 1.2 times the initial first preset sound absorption uniformity characterization parameter.

[0093] Specifically, the preset maximum number of splits is selected within the interval [30, 50].

[0094] Specifically, the process of determining the pressure change parameter for the composite product based on the reaction force of the composite product to the needling during the needling process includes:

[0095] Based on the reaction force of the composite product to acupuncture obtained at each time node, a time domain curve of the reaction force is drawn;

[0096] The difference between the maximum and minimum values ​​in the reaction force time domain curve is solved to obtain the pressure change parameter.

[0097] Specifically, there is no limitation on the specific method of obtaining the reaction force of the composite product to the needling during the needling process. It can be obtained by a pressure sensor set at the corresponding position of the needling device, and the position can be between the needling plate and the driving shaft that drives the needling plate.

[0098] Specifically, the process of adjusting the preparation parameters of the shaped product based on the pressure change parameter includes:

[0099] If the pressure variation parameter is less than or equal to the preset pressure variation parameter, adjusting the preparation parameters of the finalized product based on the difference in sound absorption of each noise frequency;

[0100] If the pressure change parameter is greater than the preset pressure change parameter, the needling frequency of the second raw material in the process of generating the bottom felt layer is adjusted to a corresponding value based on the pressure change parameter.

[0101] Specifically, the preset pressure variation parameter B0 is selected within the interval [1.3L0, 1.7L0], and L0 is the average value of the pressure variation parameters of several qualified finalized products determined in the selected historical data.

[0102] Specifically, the needling frequency of the second raw material during the production of the bottom felt layer is adjusted to a corresponding value based on the pressure variation parameter, wherein:

[0103] The increase in the frequency of needling the second raw material is positively correlated with the pressure change parameter.

[0104] In this embodiment, optionally,

[0105] Comparing the pressure change parameter with a first preset pressure comparison threshold and a second preset pressure comparison threshold;

[0106] If the pressure change parameter is less than or equal to the first preset pressure comparison threshold, the acupuncture frequency of the second raw material is adjusted to 1.11 times the initial acupuncture frequency;

[0107] If the pressure change parameter is less than or equal to the second preset pressure comparison threshold and greater than the first preset pressure comparison threshold, the acupuncture frequency of the second raw material is adjusted to 1.19 times the initial acupuncture frequency;

[0108] If the pressure change parameter is greater than the second preset pressure comparison threshold, the acupuncture frequency of the second raw material is adjusted to 1.28 times the initial acupuncture frequency;

[0109] The first preset pressure comparison threshold is 1.4B0, and the second preset pressure comparison threshold is 1.9B0.

[0110] Specifically, the process of adjusting the preparation parameters of the finalized product based on the difference in sound absorption of each noise frequency includes:

[0111] The noise frequency corresponding to the maximum value of each sound absorption difference is determined as the abnormal frequency;

[0112] If the abnormal frequency is high-frequency noise or medium-frequency noise, the frequency of the needle punching during the hole punching process is adjusted to the corresponding value based on the sound absorption uniformity characterization parameter;

[0113] If the abnormal frequency is low-frequency noise, the needle-punch perforation depth during the perforation treatment is adjusted to a corresponding value based on the sound absorption difference of the abnormal frequency.

[0114] Specifically, the pressure variation parameter is used to adjust the preparation parameters of the finalized product. The pressure variation parameter characterizes the fluctuations in the composite product's reaction force to needling during the needling process. The composite product's reaction force to needling reflects the resistance of the material's internal microstructure. The variation in reaction force is related to the degree of fiber entanglement within the material. The pressure variation parameter is obtained by plotting the reaction force time-domain curve and calculating the difference between the maximum and minimum values. This parameter reflects the dynamic changes in the material's microstructure during the needling process. When the pressure variation parameter is greater than the preset pressure variation parameter, the reaction force fluctuates significantly. This is due to excessively tight or loose fiber entanglement in the base felt layer, causing the material's internal microstructure to undergo drastic changes during the needling process. In this case, due to the unevenness of the base felt layer and local density differences, sound waves encounter the uneven structure during propagation, resulting in reflection and refraction, which prevents effective absorption and attenuation. This in turn affects the overall noise absorption, resulting in some areas having better absorption and others having poorer absorption, resulting in less stable and comprehensive noise absorption. Increasing the needling frequency in this situation allows the fibers to intertwine more tightly during the needling process, improving the uniformity of the base felt. When the pressure variation parameter is less than or equal to the preset pressure variation parameter, the manufacturing parameters of the finalized product are adjusted based on the sound absorption differences at each noise frequency. The noise frequency corresponding to the maximum sound absorption difference is identified as the abnormal frequency, as the sound absorption difference is greatest at this frequency, indicating that the product's sound absorption performance is unstable at this frequency. When the abnormal frequency is high-frequency or medium-frequency noise, the high needling frequency and overly dense pores compromise the integrity of the sound-absorbing structure, reducing the reflection and scattering of medium- and high-frequency sound waves between fibers and lowering the absorption capacity for medium- and high-frequency noise. Adjusting the needling frequency to alter the number of pores on the material surface improves high- and medium-frequency sound absorption. When the abnormal frequency is low-frequency noise, the insufficient needling amplitude and small pore diameter make it difficult for low-frequency sound waves to enter the pores, where they dissipate energy, resulting in suboptimal absorption of low-frequency noise. In this case, the needling depth during the pore-forming process is adjusted to the corresponding value, increasing the pore diameter to facilitate the transmission and absorption of low-frequency noise. Monitoring changes in the product's mechanical properties during the needling process reflects the uniformity and stability of the product's internal structure, providing data support for product anomalies. When a finalized product exhibits anomalies, the needling frequency and hole depth are adjusted to optimize the product's structure and performance, improving its sound absorption performance and making it more suitable for different acoustic environments. This also enhances the product's structural stability and further improves the efficiency of preparing porous sound-absorbing blankets.

[0115] Specifically, the frequency of needle punching during the hole punching process is adjusted to a corresponding value based on the sound absorption uniformity characterization parameter, wherein,

[0116] The reduction in the frequency of needle punching is proportional to the sound absorption uniformity characterization parameter.

[0117] In this embodiment, optionally,

[0118] Comparing the sound absorption uniformity characterization parameter with a first preset uniformity comparison threshold and a second preset uniformity comparison threshold;

[0119] If the sound absorption uniformity characterization parameter is less than or equal to the first preset uniformity comparison threshold, the needling frequency in the hole opening process is adjusted to 0.92 times the initial needling frequency;

[0120] If the sound absorption uniformity characterization parameter is less than or equal to the second preset uniformity comparison threshold and greater than the first preset uniformity comparison threshold, the needling frequency in the hole opening process is adjusted to 0.82 times the initial needling frequency;

[0121] If the sound absorption uniformity characterization parameter is greater than the second preset uniformity comparison threshold, the needling frequency during the hole opening process is adjusted to 0.72 times the initial needling frequency;

[0122] The first preset uniform comparison threshold is 1.3J2, and the second preset uniform comparison threshold is 1.4J2.

[0123] Specifically, the depth of the needle punching holes in the hole processing process is adjusted to a corresponding value based on the difference in sound absorption of the abnormal frequency, wherein,

[0124] The increase in the depth of the needle holes during the hole treatment is proportional to the difference in sound absorption at abnormal frequencies.

[0125] In this embodiment, optionally,

[0126] comparing the sound absorption difference at the abnormal frequency with a first preset sound absorption difference comparison value and a second preset sound absorption difference comparison value;

[0127] If the sound absorption difference at the abnormal frequency is less than or equal to the first preset sound absorption difference comparison value, the depth of the needle-punctured holes in the hole-punching process is increased to 1.12 times the initial needle-punctured hole depth;

[0128] If the sound absorption difference at the abnormal frequency is less than or equal to the second preset sound absorption difference comparison value and greater than the first preset sound absorption difference comparison value, the depth of the needle-punched holes in the hole-punching process is increased to 1.21 times the initial needle-punched hole depth;

[0129] If the sound absorption difference at the abnormal frequency is greater than the second preset sound absorption difference comparison value, the depth of the needle-punched holes in the hole-punching process is increased to 1.28 times the initial needle-punched hole depth;

[0130] The first preset sound absorption difference comparison value is 1.4 J, and the second preset sound absorption difference comparison value is 1.9 J, where J is a uniformity characterization parameter.

[0131] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

[0132] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. An intelligent monitoring method for the preparation of porous sound-absorbing blankets, characterized in that: include: S1, performing a needle punching treatment on the first raw material to form a surface layer; S2, needle punching the second raw material to form a bottom felt layer; S3, laminating the middle layer on one side of the surface layer, and laminating the bottom felt layer on one side of the middle layer to produce a composite product; S4, performing a needle punching process on the composite product to complete the hole punching process on the composite product; S5, heating the product after opening to obtain a finalized product; S6, determining the periodically obtained finalized product as a test product, dividing the test product into a plurality of test blocks, and determining a uniform characterization parameter of the finalized product based on the sound absorption coefficient of each test block at different noise frequencies; S7, determining whether the preparation of the finalized product is qualified based on the sound absorption uniformity characterization parameters, including: When it is determined that there is an abnormality in the preparation of the shaped product, a pressure change parameter for the composite product is determined based on the reaction force of the composite product to the needling during the needling process, and the preparation parameters of the shaped product are adjusted based on the pressure change parameter, including adjusting the needling frequency in the process of generating the base felt to a corresponding value, adjusting the needling depth in the hole opening process to a corresponding value, and adjusting the needling frequency in the hole opening process to a corresponding value; Alternatively, when it is determined that the preparation of the finalized product is qualified, the current preparation parameters are continuously used to complete the preparation of the finalized product.

2. The intelligent monitoring method for preparing porous sound-absorbing blanket according to claim 1, characterized in that: In S6, the process of determining the uniform characterization parameters of the finalized product based on the sound absorption coefficient of each detection block at different noise frequencies includes: Calculate the variance of each sound absorption coefficient of each detection block at a single noise frequency to obtain the sound absorption difference for the single noise frequency; Calculate the average value of each sound absorption difference corresponding to each noise frequency to obtain the uniformity characterization parameter; In said S7, the process of determining whether the preparation of the finalized product is qualified based on the sound absorption uniformity characterization parameter includes: When the sound absorption uniformity characterization parameter is less than or equal to the first preset sound absorption uniformity characterization parameter, it is determined that the preparation of the finalized product is qualified, and the current preparation parameters are continuously used to complete the preparation of the finalized product; When the sound absorption uniformity characterization parameter is less than or equal to the second preset sound absorption uniformity characterization parameter and greater than the first preset sound absorption uniformity characterization parameter, determining whether the preparation of the finalized product is qualified in combination with the comprehensive sound absorption difference value; When the sound absorption uniformity characterization parameter is greater than the second preset sound absorption uniformity characterization parameter, it is determined that the preparation of the shaped product is abnormal, and the pressure change parameter for the composite product is determined based on the reaction force of the composite product to the needle punching during the needle punching process, and the preparation parameters of the shaped product are adjusted based on the pressure change parameter.

3. The intelligent monitoring method for preparing porous sound-absorbing blanket according to claim 2, characterized in that: The process of determining whether the preparation of the finalized product is qualified based on the comprehensive sound absorption difference value includes: Calculate the variance of each sound absorption difference corresponding to each noise frequency to obtain the comprehensive sound absorption difference value; If the comprehensive sound absorption difference value is less than or equal to the preset comprehensive sound absorption difference value, the number of divisions of the inspection product will be adjusted to the corresponding value based on the comprehensive sound absorption difference value; If the comprehensive sound absorption difference value is greater than the preset comprehensive sound absorption difference value, it is determined that the preparation of the shaped product is abnormal. Based on the reaction force of the composite product to the needle punching during the needle punching process, the pressure change parameters for the composite product are determined, and the preparation parameters of the shaped product are adjusted based on the pressure change parameters.

4. The intelligent monitoring method for preparing porous sound-absorbing blanket according to claim 3, characterized in that: Based on the comprehensive sound absorption difference value, the number of divisions of the inspection product is adjusted to the corresponding value, wherein, The increase in the number of segments is inversely proportional to the overall sound absorption difference.

5. The intelligent monitoring method for preparing porous sound-absorbing blanket according to claim 4, characterized in that: The process of determining the pressure change parameter for the composite product based on the reaction force of the composite product to the needling during the needling process includes: Based on the reaction force of the composite product to acupuncture obtained at each time node, a time domain curve of the reaction force is drawn; The difference between the maximum and minimum values ​​in the reaction force time domain curve is solved to obtain the pressure change parameter.

6. The intelligent monitoring method for preparing porous sound-absorbing blanket according to claim 5, characterized in that: The process of adjusting the preparation parameters of the shaped product based on the pressure change parameter includes: If the pressure variation parameter is less than or equal to the preset pressure variation parameter, adjusting the preparation parameters of the finalized product based on the difference in sound absorption of each noise frequency; If the pressure change parameter is greater than the preset pressure change parameter, the needling frequency of the second raw material in the process of generating the bottom felt layer is adjusted to a corresponding value based on the pressure change parameter.

7. The intelligent monitoring method for preparing porous sound-absorbing blanket according to claim 6, characterized in that: Based on the pressure variation parameter, the needling frequency of the second raw material during the production of the bottom felt layer is adjusted to a corresponding value, wherein, The increase in the frequency of needling the second raw material is positively correlated with the pressure change parameter.

8. The intelligent monitoring method for preparing porous sound-absorbing blanket according to claim 7, characterized in that: The process of adjusting the preparation parameters of the finalized product based on the difference in sound absorption of each noise frequency includes: The noise frequency corresponding to the maximum value of each sound absorption difference is determined as the abnormal frequency; If the abnormal frequency is high-frequency noise or medium-frequency noise, the frequency of the needle punching during the hole punching process is adjusted to the corresponding value based on the sound absorption uniformity characterization parameter; If the abnormal frequency is low-frequency noise, the needle-punch perforation depth during the perforation treatment is adjusted to a corresponding value based on the sound absorption difference of the abnormal frequency.

9. The intelligent monitoring method for preparing porous sound-absorbing blanket according to claim 8, characterized in that: The frequency of the needle punching during the hole opening process is adjusted to the corresponding value based on the sound absorption uniformity characterization parameter, wherein, The reduction in the frequency of needle punching is proportional to the sound absorption uniformity characterization parameter.

10. The intelligent monitoring method for preparing porous sound-absorbing blanket according to claim 9, characterized in that: The depth of the needle punched holes in the hole processing process is adjusted to the corresponding value based on the difference in sound absorption of the abnormal frequency, wherein, The increase in the depth of the needle holes during the hole treatment is proportional to the difference in sound absorption at abnormal frequencies.

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