Blanket air permeability detection system based on intelligent sensor

Abstract

The invention relates to the technical field of automatic nondestructive testing, in particular to a blanket breathability detection system based on an intelligent sensor. The system comprises a suspension positioning module, a double-chamber pneumatic module, an isobaric guard module, a ventilation calculation module and a self-adaptive compensation module. The system drives a detection head to accurately stay at a zero-stress contact position to establish a physical boundary by collecting morphology data of a soft porous material; the core is that a coaxial flow field is constructed by utilizing a double-chamber pneumatic structure, the pressure of an outer cavity is dynamically adjusted by an isobaric protection module, and the pressure balance of an inner cavity and the pressure balance of the outer cavity are ensured so as to block airflow lateral leakage; after the lateral gradient is eliminated, the ventilation calculation module calculates the intrinsic permeability of the material according to the flow of the inner cavity and the pressure difference; according to the invention, the problems of pore collapse and index underestimation caused by physical compression in traditional clamping measurement are effectively solved, and accurate air permeability detection of the long velvet material in a natural state is realized.

Description

Technical Field

[0001] This invention relates to the field of automated nondestructive testing technology, specifically to a blanket air permeability testing system based on intelligent sensors. Background Technology

[0002] In the field of air permeability testing of soft porous materials, existing testing methods for non-homogeneous materials such as long-pile blankets generally face technical bottlenecks such as difficulty in defining measurement boundary conditions and large data deviations.

[0003] Due to the high compressibility and porous dispersion of the material, traditional mechanical clamping measurement establishes a sealed boundary through physical compression. This inevitably leads to mechanical compression and structural collapse of the internal pores of the material, resulting in a severe underestimation of the air permeability index. Although non-contact measurement avoids structural compression, the gap between the detection head and the material surface can cause severe lateral airflow leakage, causing the flow meter reading to include a large amount of invalid lateral diffusion components, resulting in a significant overestimation of the air permeability index. In addition, the impediment effect of the pile layer itself is intertwined with the intrinsic air permeability of the base material, and environmental disturbances can easily cause the detection state to become unstable, making it difficult to obtain pure data that reflects the quality of the material's textile process.

[0004] Therefore, how to eliminate lateral leakage interference and decouple complex flow resistance contributions without disrupting the natural loose state of the material, and improve the non-invasiveness of the detection process and the accuracy of intrinsic permeability calculation, has become an urgent technical problem to be solved. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a blanket breathability detection system based on intelligent sensors. Specifically, the technical solution of this invention includes:

[0006] The suspension positioning module is used to collect the morphology data of the surface of the soft porous material and drive the detection head to perform a feeding action based on the morphology data, so that the bottom surface of the detection head stops at the zero-stress contact position of the soft porous material. The zero-stress contact position is defined as the position where the detection head contacts the surface of the material's fluff layer without compressing the substrate, thereby establishing the detection physical boundary.

[0007] The dual-chamber pneumatic module is used to construct a coaxially distributed flow field environment, establish the target test pressure difference in the inner cavity of the detection head, and simultaneously establish a protective pressure field in the outer cavity surrounding the inner cavity;

[0008] The isobaric protection module is used to monitor the pressure gradient between the inner and outer cavities in real time, and dynamically adjust the protective pressure field of the outer cavity based on the pressure gradient, forcing the pressure in the outer cavity to remain in balance with the pressure in the inner cavity, forming a pressure balance boundary at the interface between the inner and outer cavities, eliminating the lateral pressure gradient to block the lateral leakage path of the airflow.

[0009] The air permeability calculation module is used to acquire only the fluid flow rate data flowing through the inner cavity under the condition that the pressure balance boundary is established and stable, and calculate the intrinsic permeability index of the soft porous material by combining it with the target test pressure difference.

[0010] The adaptive compensation module is used to generate feedback commands to the suspension positioning module and the dual-chamber pneumatic module based on the fluctuation characteristics of the fluid flow data, so as to realize closed-loop correction of the detection status.

[0011] Preferably, the levitation positioning module includes:

[0012] The topography scanning unit is used to perform high-frequency scanning on the surface of soft porous materials using a non-contact ranging sensor to obtain information on the height of the velvet layer and the location of the substrate on the material surface, and to generate a surface topography dataset.

[0013] The micro-motion servo unit is used to control the precision stepper motor to drive the detection head to move vertically up and down based on the surface morphology dataset. When the bottom surface of the detection head contacts the top of the fluff layer and does not cause compression deformation to the substrate, the current vertical coordinate is locked as the zero-stress contact position to ensure that the material pore structure remains in a natural and fluffy state.

[0014] Preferably, the dual-chamber pneumatic module includes:

[0015] The internal cavity actuation unit is used to control the main fan connected to the internal cavity and stabilize the internal cavity pressure at the target test pressure difference according to the preset test standard.

[0016] The outer cavity follower unit is used to control the outer cavity auxiliary fan connected to the outer cavity. In response to the adjustment command of the isobaric protection module, it independently adjusts the pressure of the outer cavity, so that the outer cavity forms an isobaric protection ring around the inner cavity with the same pressure value as the inner cavity, thereby eliminating the pressure potential energy of the gas in the inner cavity diffusing outward.

[0017] Preferably, the isobaric protection module includes:

[0018] The differential pressure monitoring unit is used to read the internal and external pressure values ​​in real time through a high-precision differential pressure transmitter and to calculate the pressure difference between the internal and external cavities.

[0019] The zero-pressure anchoring unit is configured to input the pressure difference between the inner and outer cavities as a feedback variable into the PID controller, with zero Pascal as the control target, and output a speed regulation command to the outer cavity following unit; if the pressure difference between the inner and outer cavities is positive, a command to increase the pressure of the outer cavity is generated; if the pressure difference between the inner and outer cavities is negative, a command to decrease the pressure of the outer cavity is generated, until the absolute value of the pressure difference between the inner and outer cavities converges within the zero-pressure threshold range, ensuring that the airflow vector flowing through the inner cavity is distributed only in the vertical direction.

[0020] Preferably, the breathability calculation module includes:

[0021] The flow resistance decoupling unit is used to distinguish the flow resistance contribution of the pile layer and the base fabric layer. It calls the pile layer height information in the surface morphology dataset and, based on the principle of flow resistance series superposition, regards the total flow resistance as the sum of the flow resistance of the base fabric layer and the flow resistance of the pile layer. It calculates the flow resistance component caused by the pile layer and subtracts it from the total flow resistance, thereby extracting the net flow resistance data of the base fabric layer.

[0022] The intrinsic calculation unit is used to calculate the vertical permeability of soft porous materials in a non-mechanically compressed state based on net flow resistance data and the geometric cross-sectional area of ​​the cavity, eliminating pore closure errors caused by mechanical clamping.

[0023] Preferably, the adaptive compensation module includes:

[0024] The dynamic balancing unit is used to monitor the change in the relative distance between the detection head and the material surface when the soft porous material is in a state of relative motion. If the change in relative distance exceeds the preset safety range, the suspension positioning module is immediately triggered to adjust the height and maintain the continuity of the zero-stress contact state.

[0025] The leakage early warning unit is configured to monitor the output power of the external cavity auxiliary fan. If the output power of the external cavity auxiliary fan exceeds the preset leakage limit threshold, it determines that there is structural damage or edge effect at the current detection location and generates an abnormal status label attached to the current fluid flow data. If the output power of the external cavity auxiliary fan does not exceed the leakage limit threshold, it maintains normal monitoring status.

[0026] Preferably, the system further includes:

[0027] The calibration module is used to perform benchmark calibration on the system before testing. It uses a standard zero-permeability calibration plate to seal the bottom surface of the test head, starts the dual-chamber pneumatic module, and tests the static leakage rate of the inner cavity.

[0028] The configuration is as follows: if the static leakage rate is higher than the system's allowable error threshold, the venting calculation module will be disabled and a sealing fault alarm will be output; if the static leakage rate is not higher than the system's allowable error threshold, the venting calculation module will be enabled.

[0029] Preferably, the zero-pressure threshold range is set to ±0.5 Pascals;

[0030] The configuration is as follows: monitor the duration for which the pressure difference between the inner and outer cavities is within the zero-pressure threshold range; if the duration exceeds the preset stability determination period, activate the air permeability calculation module to perform data acquisition; if the duration does not exceed the preset stability determination period, remain in a waiting state to ensure that the acquired data is entirely based on the vertical flow field.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] 1. This system uses a suspension positioning module and a non-contact ranging sensor to precisely control the detection head to stay at the zero-stress contact position. This design ensures that soft porous materials such as long-pile blankets remain naturally fluffy during the detection process, effectively solving the problem that the air permeability index is underestimated due to pore compression and structural collapse caused by physical clamping in traditional mechanical clamping measurements.

[0033] 2. This system utilizes the synergistic effect of the dual-chamber pneumatic module and the isobaric protection module to construct a dynamically balanced isobaric protection ring around the inner cavity; by eliminating the pressure gradient between the inner and outer cavities in real time, a virtual pressure balance boundary is formed inside the fabric, blocking the lateral diffusion path of airflow and solving the technical bottleneck of overestimation of air permeability index due to edge leakage in non-contact measurement.

[0034] 3. The air permeability calculation module of this system distinguishes the flow resistance contribution of the pile layer and the base fabric layer through surface morphology data; based on the principle of flow resistance series superposition, the system can accurately remove the interference component of the pile layer from the total flow resistance, thereby extracting the net flow resistance data determined only by the base fabric structure; this makes the final output permeability index purely reflect the textile process quality of the material, providing accurate data support for production process optimization.

[0035] 4. The adaptive compensation module and calibration module of this system endow the system with self-sensing and diagnostic capabilities; the system can cope with the dynamic fluctuations of the material surface and adjust the detection height in real time. At the same time, by monitoring power anomalies and performing pre-start self-tests, it automatically identifies and eliminates invalid data caused by structural damage or sealing failure, ensuring the scientific nature and repeatability of the test results in complex industrial environments. Attached Figure Description

[0036] The present invention will be further explained below with reference to the accompanying drawings and embodiments:

[0037] Figure 1 This is a structural diagram of the system of the present invention. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0039] Example 1:

[0040] Please see Figure 1 A blanket breathability detection system based on smart sensors, comprising:

[0041] The suspension positioning module is used to collect the morphology data of the surface of the soft porous material and drive the detection head to perform a feeding action based on the morphology data, so that the bottom surface of the detection head stops at the zero-stress contact position of the soft porous material. The zero-stress contact position is defined as the position where the detection head contacts the surface of the material's fluff layer without compressing the substrate, thereby establishing the physical boundary of the detection.

[0042] The dual-chamber pneumatic module is used to construct a coaxially distributed flow field environment, establish the target test pressure difference in the inner cavity of the detection head, and simultaneously establish a protective pressure field in the outer cavity surrounding the inner cavity;

[0043] The isobaric protection module is used to monitor the pressure gradient between the inner and outer cavities in real time, and dynamically adjust the protective pressure field of the outer cavity based on the pressure gradient, forcing the pressure in the outer cavity to remain in balance with the pressure in the inner cavity, forming a pressure balance boundary at the interface between the inner and outer cavities, eliminating the lateral pressure gradient to block the lateral leakage path of the airflow.

[0044] The air permeability calculation module is used to acquire only the fluid flow rate data flowing through the inner cavity under the condition that the pressure balance boundary is established and stable, and calculate the intrinsic permeability index of the soft porous material by combining it with the target test pressure difference.

[0045] The adaptive compensation module is used to generate feedback commands to the suspension positioning module and the dual-chamber pneumatic module based on the fluctuation characteristics of the fluid flow data, so as to realize closed-loop correction of the detection status.

[0046] This embodiment describes in detail the overall architecture and workflow of the system, aiming to resolve the physical contradiction in the detection process of soft porous materials, where mechanical compression leads to an underestimation of air permeability and lateral leakage leads to an overestimation of air permeability.

[0047] The system constructs a non-invasive physical interface for detection through a levitation positioning module. This module uses high-precision sensors to collect morphological data of soft porous materials, such as long-pile blankets, and drives the detection head to perform a feeding action, so that the bottom surface of the detection head precisely stops at a zero-stress contact position. This position is physically defined as the spatial coordinate where the bottom surface of the detection head just contacts the pile layer of the material surface, but has not yet produced any compressive deformation on the underlying substrate structure, i.e., the contact pressure is close to zero, thereby ensuring that the porosity inside the material remains in a natural and fluffy state.

[0048] The dual-chamber pneumatic module constructs a physical flow field to prevent lateral airflow diffusion. The module adopts a coaxial dual-cylindrical cavity structure, establishing a target test pressure difference in the central inner cavity, such as a pressure drop of 100Pa set according to the process standard, and simultaneously establishing a protective pressure field in the outer cavity surrounding the inner cavity.

[0049] The isobaric protection module actively eliminates the pressure potential energy that causes lateral leakage. This module monitors the pressure gradient between the inner and outer cavity pressures in real time and dynamically adjusts the protective pressure field of the outer cavity to force the outer cavity pressure to maintain a strict balance with the inner cavity pressure. This forms a pressure balance boundary below the physical partition between the inner and outer cavities, which is a virtual pressure-free interface formed inside the fabric due to the equal pressure on both sides. Based on this, after establishing the pressure balance boundary and stabilizing the state, the air permeability calculation module obtains only the fluid flow rate data flowing through the inner cavity through a high-precision flow meter and calculates the intrinsic permeability index of the soft porous material by combining it with the target test pressure difference.

[0050] The adaptive compensation module generates feedback commands to the suspension positioning module and the dual-chamber pneumatic module based on the fluctuation characteristics of the fluid flow data, realizing closed-loop correction of the detection state. This ensures that the system can maintain zero-stress contact and isobaric protection under external disturbances. In the precision detection scenario of soft, non-homogeneous materials, zero-stress contact ensures that the pores of the blanket are not compressed, solving the problem of low readings caused by traditional mechanical clamping. At the same time, the virtual air wall constructed by the isobaric protection blocks lateral leakage, solving the problem of high readings caused by non-contact measurement. The two work together to achieve non-destructive and accurate measurement of the true intrinsic permeability of the material without damaging the material sample.

[0051] Example 2:

[0052] The hover positioning module includes:

[0053] The topography scanning unit is used to perform high-frequency scanning on the surface of soft porous materials using a non-contact ranging sensor to obtain information on the height of the velvet layer and the location of the substrate on the material surface, and to generate a surface topography dataset.

[0054] The micro-motion servo unit is used to control the precision stepper motor to drive the detection head to move vertically up and down based on the surface morphology dataset. When the bottom surface of the detection head contacts the top of the fluff layer and does not cause compression deformation to the substrate, the current vertical coordinate is locked as the zero-stress contact position to ensure that the material pore structure remains in a natural and fluffy state.

[0055] This embodiment provides a specific design for the levitation positioning module and adopts an opto-mechatronics coordinated control strategy;

[0056] The topography scanning unit is configured to use a laser triangulation rangefinder or a spectral confocal sensor as a non-contact ranging element; this unit performs high-frequency line scanning or area scanning on the surface of soft porous materials, with a scanning frequency of not less than 1kHz; to solve the black-box problem of signal recognition, this embodiment sets specific signal processing logic: for highly reflective substrate materials, such as light-colored dense fabrics, the system preset logic conditions are as follows: For dark, light-absorbing substrates, the logic needs to be reversed in the configuration. ;

[0057] In the specific description of this embodiment, it is assumed that The reflected light intensity signal received by the sensor Real-time analysis will satisfy The time point corresponding to the first rising edge Solving for the coordinates of the top of the fluff layer , will satisfy And the time point corresponding to the signal peak with local maximum value Solve for the base position coordinates Thus generating a collection and Surface morphology dataset;

[0058] The micro-motion servo unit receives the surface topography dataset and controls a precision stepper motor with grating ruler feedback. The motor has a Z-axis resolution better than 10 micrometers, which drives the detection head to move vertically up and down.

[0059] Execute specific control logic: the detection head rapidly descends to a preset safe distance from the material surface, such as 5mm, and then switches to a slow micro-feed mode, such as 0.1mm / s; in response to the Z-coordinate of the bottom surface of the detection head satisfying specific geometric conditions, i.e. At that time, among them The system determines that the natural height of the villous layer is when the coordinates of the detected head bottom surface are equal to the base position plus the height of the villous layer, and the detected head bottom surface is in contact with the top of the villous layer without compressing the base.

[0060] The system immediately locks the current vertical coordinate as the zero-stress contact position;

[0061] This embodiment utilizes a bimodal recognition algorithm based on intensity thresholds to distinguish between the pile and the substrate, enabling the detection head to gently adhere to the blanket surface like a holographic image. This ensures that the internal pore channels of the material maintain their natural fluffy state as they were at the factory, avoiding measurement errors caused by the collapse of the microstructure due to physical contact, thereby guaranteeing the authenticity of the detection boundary conditions at the microscopic level.

[0062] Example 3:

[0063] The dual-chamber pneumatic module includes:

[0064] The internal cavity actuation unit is used to control the main fan connected to the internal cavity and stabilize the internal cavity pressure at the target test pressure difference according to the preset test standard.

[0065] The outer cavity follower unit is used to control the outer cavity auxiliary fan connected to the outer cavity. In response to the adjustment command of the isobaric protection module, it independently adjusts the pressure of the outer cavity, so that the outer cavity forms an isobaric protection ring around the inner cavity with the same pressure value as the inner cavity, thereby eliminating the pressure potential energy of the gas in the inner cavity diffusing outward.

[0066] This embodiment details the hardware topology and control logic of the dual-chamber pneumatic module;

[0067] The internal cavity actuation unit controls the main fan connected to the internal cavity air path, such as a high dynamic response brushless DC fan; the unit reads the preset test standard and adjusts the speed of the main fan through PID control to stabilize the internal cavity pressure at the target test pressure difference;

[0068] The external cavity follower unit controls the external cavity auxiliary fan connected to the external cavity air path; this unit does not independently set the pressure target, but responds to the adjustment command of the isobaric protection module;

[0069] The core task of this unit is to construct an isobaric protective ring, that is, an annular high-pressure region formed in the outer cavity, whose pressure value is forced to follow the pressure in the inner cavity; in this process, according to the principle of fluid mechanics, the fluid always flows from the high-pressure area to the low-pressure area; by making the pressure difference between the inner cavity edge and the outer cavity edge zero, the gas in the inner cavity lacks the power to diffuse outward, thus being forced to pass through the material only in the vertical direction.

[0070] This embodiment uses a master-slave aerodynamic architecture, where the external auxiliary fan acts as a bodyguard for the internal flow field, eliminating edge effects and enabling near-perfect flow field constraint even without physical sealing rings. This creates an ideal vertical flow test environment under open boundary conditions.

[0071] Example 4:

[0072] The isobaric protection module includes:

[0073] The differential pressure monitoring unit is used to read the internal and external pressure values ​​in real time through a high-precision differential pressure transmitter and to calculate the pressure difference between the internal and external cavities.

[0074] The zero-pressure anchoring unit is configured to input the pressure difference between the inner and outer cavities as a feedback variable into the PID controller, with zero Pascal as the control target, and output a speed regulation command to the outer cavity following unit; if the pressure difference between the inner and outer cavities is positive, a command to increase the pressure of the outer cavity is generated; if the pressure difference between the inner and outer cavities is negative, a command to decrease the pressure of the outer cavity is generated, until the absolute value of the pressure difference between the inner and outer cavities converges within the zero-pressure threshold range, ensuring that the airflow vector flowing through the inner cavity is distributed only in the vertical direction.

[0075] This embodiment specifically illustrates the core algorithm for achieving millisecond-level pressure balance in the isobaric protection module; the differential pressure monitoring unit is equipped with a high-precision differential pressure transmitter with a sampling frequency of not less than 500Hz; this unit reads the external cavity pressure value in real time. And obtain the target set value of the internal cavity pressure. , here That is, the pressure tracking error at the current sampling moment is calculated based on the target test pressure difference described in Example 1, or the steady-state pressure value of the cavity after low-pass filtering.

[0076]

[0077] The control objective here is to eliminate the deviation between the two; the zero-pressure anchoring unit adopts a discrete incremental PID control strategy to reduce the aforementioned error. As input; the output of the PID controller Calculate using the following formula:

[0078]

[0079]

[0080] The system performs amplitude limiting on the output: if Then let ;like Then let To prevent the saturation and overflow of fan speed control commands; among which, For the pre-tuned proportional, integral, and differential coefficients, The PWM speed control command mapped to the external cavity auxiliary fan is transmitted to the external cavity follower unit;

[0081] The system executes specific adjustment logic: if the calculated If the pressure increases, the speed of the auxiliary fan in the external cavity will be increased to raise the pressure in the external cavity; if... If the speed is reduced, the speed of the auxiliary fan in the external cavity will also decrease; this process is repeated cyclically until the error is reached. The absolute value converges within the zero-pressure threshold range;

[0082] This embodiment uses PID closed-loop control based on a mathematical model, rather than simple on / off control, to ensure that the airflow vector field flowing through the inner cavity is strictly constrained in the Z-axis direction, i.e., the vertical direction. This ensures that the flow rate data measured under open boundary conditions truly represents the vertical permeability of the material, eliminating systematic errors caused by flow field distortion.

[0083] Example 5:

[0084] The breathability calculation module includes:

[0085] The flow resistance decoupling unit is used to distinguish the flow resistance contribution of the pile layer and the base fabric layer. It calls the pile layer height information in the surface morphology dataset and, based on the principle of flow resistance series superposition, regards the total flow resistance as the sum of the flow resistance of the base fabric layer and the flow resistance of the pile layer. It calculates the flow resistance component caused by the pile layer and subtracts it from the total flow resistance, thereby extracting the net flow resistance data of the base fabric layer.

[0086] The intrinsic calculation unit is used to calculate the vertical permeability of soft porous materials in a non-mechanically compressed state based on net flow resistance data and the geometric cross-sectional area of ​​the cavity, eliminating pore closure errors caused by mechanical clamping.

[0087] This embodiment primarily addresses the interference of the fluff layer on fluid resistance by achieving precise decoupling of material flow resistance characteristics through a permeability calculation module. The flow resistance decoupling unit distinguishes the physical contributions of the fluff layer and the base fabric layer. Based on the principle of series superposition of flow resistance in compressible fluids, this unit utilizes the fluff layer height information from the surface topography dataset. To accurately calculate the net flow resistance data of the base fabric layer, this embodiment introduces a decoupling model:

[0088]

[0089] in, The source is real-time calculation, derived from the pressure difference measured in the internal cavity. Divide by the measured flow rate To obtain, that is Traffic here It needs to be converted to standard international units first. The physical meaning is total flow resistance, and the unit is 1. ; The source is a pre-defined function relationship, which is obtained during the system's factory calibration phase: A set of samples of the same material are selected and pre-treated with precision shearing, such as by using liquid nitrogen cryo-fixation followed by laser tomography cutting technology, to ensure that the fibers do not collapse or the cut surfaces fuse together during the cutting process, thereby maintaining the microporous structure and giving each sample a different natural fiber height. Covering from At the maximum process height, the flow resistance value of each sample was measured under zero-stress contact conditions. A quadratic polynomial relationship with respect to the natural height was obtained by fitting using the least squares method.

[0090]

[0091] in, The dimensions are , The dimensions are , The dimensions are This is to ensure that the physical dimensions on both sides of the equation remain consistent in the flow resistance calculation; among them, These are calibration constants stored in the system; The data originates from measurement data from the levitation positioning module, and its physical meaning is the height of the fluff layer, measured in meters (m).

[0092] By subtracting the function from the total flow resistance The calculated flow resistance component of the fluff layer is used to extract the net flow resistance data determined solely by the base fabric structure. Based on this, the intrinsic calculation unit is used to calculate the vertical permeability of the soft porous material under uncompressed conditions, according to a modified form of Darcy's law.

[0093]

[0094] in, For calculation output, the physical meaning is intrinsic vertical permeability, in m²; The source is an ambient temperature sensor (lookup table), and the physical meaning is aerodynamic viscosity, with the unit being Pa·s. The calculated value is given by the following formula:

[0095]

[0096] in, The coordinates of the substrate reflecting surface identified by the topography scanning unit. The absolute Z-axis coordinate of the pre-calibrated rigid support platform surface; The physical meaning is the thickness of the base fabric layer, with units of . ; For system constants, the physical meaning is the geometric cross-sectional area of ​​the inner cavity, with the unit being m². This embodiment not only eliminates mechanical compression errors, but also eliminates the obstruction and interference of the pile layer itself on airflow through explicit function mapping, so that the final output air permeability index purely reflects the textile process quality of the base fabric material, such as warp and weft density, providing purer data support for production process optimization.

[0097] Example 6:

[0098] The adaptive compensation module includes:

[0099] The dynamic balancing unit is used to monitor the change in the relative distance between the detection head and the material surface when the soft porous material is in a state of relative motion. If the change in relative distance exceeds the preset safety range, the suspension positioning module is immediately triggered to adjust the height and maintain the continuity of the zero-stress contact state.

[0100] The leakage early warning unit is configured to monitor the output power of the external cavity auxiliary fan. If the output power of the external cavity auxiliary fan exceeds the preset leakage limit threshold, it determines that there is structural damage or edge effect at the current detection location and generates an abnormal status label attached to the current fluid flow data. If the output power of the external cavity auxiliary fan does not exceed the leakage limit threshold, it maintains normal monitoring status.

[0101] This embodiment enhances the functionality of the adaptive compensation module, primarily addressing uncertainties in the dynamic detection process.

[0102] The dynamic balancing unit is suitable for scenarios where the blanket moves relative to the detection head on the production line; this unit continuously monitors changes in the relative distance between the detection head and the material surface; in response to changes in the relative distance exceeding a preset safety range, for example... mm indicates that the material surface has wavy undulations. The system immediately triggers the suspension positioning module to adjust the height, maintain the continuity of zero-stress contact state, and prevent the detection head from hitting the fabric surface or losing contact.

[0103] The leakage warning unit is configured to monitor the output power of the external cavity auxiliary fan; its judgment logic is based on the physical fact that the energy required to maintain the external cavity pressure is relatively stable under normal isobaric equilibrium conditions.

[0104] This embodiment defines a leakage limit threshold. The acquisition method is as follows: When the system starts up for the first time, the power value of the first successful test cycle is assigned to it by default. Initialization is complete; during runtime, a sliding window calculation is performed to reflect past events. Average power of external auxiliary fan in a normal test cycle ,set up The dynamic threshold, together with the static leakage rate index in the calibration module, constitutes the system's multi-dimensional airtightness monitoring system.

[0105] The system uses a real-time comparison function The sign is used for judgment, where, To monitor power in real time; in response to the real-time output power of the external auxiliary fan exceeding the dynamically generated leakage limit threshold. This indicates that the external cavity auxiliary fan is consuming abnormally high power to maintain pressure, which usually means that there is a huge gas leak at the physical boundary, such as a broken edge of the blanket or a large hole in the fabric. At this time, the system determines that there is structural damage or edge effect at the detection location and generates an abnormal status label attached to the current fluid flow data. In response to the output power of the external cavity auxiliary fan not exceeding the leakage limit threshold, the normal monitoring status is maintained.

[0106] This embodiment endows the system with the ability of self-sensing and self-diagnosis, enabling it to adapt to the complex working conditions of industrial sites, automatically eliminate invalid data, ensure the robustness of test results, and avoid misjudgment of overall quality due to local defects in materials.

[0107] Example 7:

[0108] The system also includes:

[0109] The calibration module is used to perform benchmark calibration on the system before testing. It uses a standard zero-permeability calibration plate to seal the bottom surface of the test head, starts the dual-chamber pneumatic module, and tests the static leakage rate of the inner cavity.

[0110] The configuration is as follows: if the static leakage rate is higher than the system's allowable error threshold, the venting calculation module will be disabled and a sealing fault alarm will be output; if the static leakage rate is not higher than the system's allowable error threshold, the venting calculation module will be enabled.

[0111] This embodiment describes the calibration module during the system startup phase, used to perform a system health self-check. The operator completely seals the bottom of the test head using a standard, precision-machined, non-perforated plate (zero permeability plate). The dual-chamber pneumatic module is activated, and the internal pressure is set to the standard test pressure. The fluid flow rate within the chamber is detected by a flow sensor; this flow rate is defined as the static leakage rate. Based on this, the system executes a comparison logic: if the static leakage rate exceeds the system's allowable error threshold (e.g., 0.01 L / min), it indicates a sealing failure in the system's internal air path, such as aging pipes or loose fan interfaces. The system prohibits the activation of the permeability calculation module and outputs a sealing fault alarm. If the static leakage rate does not exceed the system's allowable error threshold, the system hardware is considered intact, and subsequent modules are allowed to start.

[0112] This embodiment ensures that all measured minute flow rates are indeed through the blanket, rather than due to leakage in the system itself, establishing a confidence benchmark for the measurement and providing a reliable zero-point reference for high-precision micro-flow rate measurement.

[0113] Example 8:

[0114] The zero-pressure threshold range is set to ±0.5 Pascals;

[0115] The configuration is as follows: monitor the duration for which the pressure difference between the inner and outer cavities is within the zero-pressure threshold range; if the duration exceeds the preset stability determination period, activate the air permeability calculation module to perform data acquisition; if the duration does not exceed the preset stability determination period, remain in a waiting state to ensure that the acquired data is entirely based on the vertical flow field.

[0116] In this embodiment, the stability judgment logic of the isobaric protection module is quantitatively defined; the zero-pressure threshold range is specifically set to ±0.5 Pascals; this is an extremely high-precision physical equilibrium window, within which the lateral diffusion rate of the gas is negligible; the configured control logic starts a timer to monitor the duration for which the pressure difference between the inner and outer chambers is within ±0.5 Pa, i.e., the condition is met. continuous time period If the duration exceeds the preset stability determination period, such as 200ms, it indicates that the flow field has established a steady-state vertical distribution. At this time, the system activates the air permeability calculation module and triggers the sampling action of the flow meter data. If the duration does not exceed the preset stability determination period, it is considered that the flow field is still in the oscillation or transient adjustment period, the data is unreliable, and the system remains in a waiting state.

[0117] This embodiment ensures that each set of recorded data is collected under the premise that the physical boundary conditions strictly meet the assumption of a pure vertical flow field through strict time-pressure thresholds and logic, which greatly improves the scientificity and repeatability of the data and eliminates the interference of transient airflow disturbances on the measurement results.

[0118] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A blanket air permeability detection system based on intelligent sensors, characterized in that, include: The suspension positioning module is used to collect the morphology data of the surface of the soft porous material and drive the detection head to perform a feeding action based on the morphology data, so that the bottom surface of the detection head stops at the zero-stress contact position of the soft porous material. The zero-stress contact position is defined as the position where the detection head contacts the surface of the material's fluff layer without compressing the substrate, thereby establishing the detection physical boundary. The dual-chamber pneumatic module is used to construct a coaxially distributed flow field environment, establish the target test pressure difference in the inner cavity of the detection head, and simultaneously establish a protective pressure field in the outer cavity surrounding the inner cavity; The isobaric protection module is used to monitor the pressure gradient between the inner and outer cavities in real time, and dynamically adjust the protective pressure field of the outer cavity based on the pressure gradient, forcing the pressure in the outer cavity to remain in balance with the pressure in the inner cavity, forming a pressure balance boundary at the interface between the inner and outer cavities, eliminating the lateral pressure gradient to block the lateral leakage path of the airflow. The air permeability calculation module is used to acquire only the fluid flow rate data flowing through the inner cavity under the condition that the pressure balance boundary is established and stable, and calculate the intrinsic permeability index of the soft porous material by combining it with the target test pressure difference. The adaptive compensation module is used to generate feedback commands to the suspension positioning module and the dual-chamber pneumatic module based on the fluctuation characteristics of the fluid flow data, so as to realize closed-loop correction of the detection status.

2. The blanket air permeability detection system based on intelligent sensors according to claim 1, characterized in that, The hover positioning module includes: The topography scanning unit is used to perform high-frequency scanning on the surface of soft porous materials using a non-contact ranging sensor to obtain information on the height of the velvet layer and the location of the substrate on the material surface, and to generate a surface topography dataset. The micro-motion servo unit is used to control the precision stepper motor to drive the detection head to move vertically up and down based on the surface morphology dataset. When the bottom surface of the detection head contacts the top of the fluff layer and does not cause compression deformation to the substrate, the current vertical coordinate is locked as the zero-stress contact position to ensure that the material pore structure remains in a natural and fluffy state.

3. The blanket air permeability detection system based on intelligent sensors according to claim 1, characterized in that, The dual-chamber pneumatic module includes: The internal cavity actuation unit is used to control the main fan connected to the internal cavity and stabilize the internal cavity pressure at the target test pressure difference according to the preset test standard. The outer cavity follower unit is used to control the outer cavity auxiliary fan connected to the outer cavity. In response to the adjustment command of the isobaric protection module, it independently adjusts the pressure of the outer cavity, so that the outer cavity forms an isobaric protection ring around the inner cavity with the same pressure value as the inner cavity, thereby eliminating the pressure potential energy of the gas in the inner cavity diffusing outward.

4. The blanket air permeability detection system based on intelligent sensors according to claim 3, characterized in that, The isobaric protection module includes: The differential pressure monitoring unit is used to read the internal and external pressure values ​​in real time through a high-precision differential pressure transmitter and to calculate the pressure difference between the internal and external cavities. The zero-pressure anchoring unit is configured to input the pressure difference between the inner and outer cavities as a feedback variable into the PID controller, with zero Pascal as the control target, and output a speed regulation command to the outer cavity following unit; if the pressure difference between the inner and outer cavities is positive, a command to increase the pressure of the outer cavity is generated; if the pressure difference between the inner and outer cavities is negative, a command to decrease the pressure of the outer cavity is generated, until the absolute value of the pressure difference between the inner and outer cavities converges within the zero-pressure threshold range, ensuring that the airflow vector flowing through the inner cavity is distributed only in the vertical direction.

5. The blanket air permeability detection system based on intelligent sensors according to claim 2, characterized in that, The breathability calculation module includes: The flow resistance decoupling unit is used to distinguish the flow resistance contribution of the pile layer and the base fabric layer. It calls the pile layer height information in the surface morphology dataset and, based on the principle of flow resistance series superposition, regards the total flow resistance as the sum of the flow resistance of the base fabric layer and the flow resistance of the pile layer. It calculates the flow resistance component caused by the pile layer and subtracts it from the total flow resistance, thereby extracting the net flow resistance data of the base fabric layer. The intrinsic calculation unit is used to calculate the vertical permeability of soft porous materials in a non-mechanically compressed state based on net flow resistance data and the geometric cross-sectional area of ​​the cavity, eliminating pore closure errors caused by mechanical clamping.

6. The blanket air permeability detection system based on intelligent sensors according to claim 1, characterized in that, The adaptive compensation module includes: The dynamic balancing unit is used to monitor the change in the relative distance between the detection head and the material surface when the soft porous material is in a state of relative motion. If the change in relative distance exceeds the preset safety range, the suspension positioning module is immediately triggered to adjust the height and maintain the continuity of the zero-stress contact state. The leakage early warning unit is configured to monitor the output power of the external cavity auxiliary fan. If the output power of the external cavity auxiliary fan exceeds the preset leakage limit threshold, it determines that there is structural damage or edge effect at the current detection location and generates an abnormal status label attached to the current fluid flow data. If the output power of the external cavity auxiliary fan does not exceed the leakage limit threshold, it maintains normal monitoring status.

7. The blanket air permeability detection system based on intelligent sensors according to claim 1, characterized in that, The system also includes: The calibration module is used to perform benchmark calibration on the system before testing. It uses a standard zero-permeability calibration plate to seal the bottom surface of the test head, starts the dual-chamber pneumatic module, and tests the static leakage rate of the inner cavity. The configuration is as follows: if the static leakage rate is higher than the system's allowable error threshold, the venting calculation module will be disabled and a sealing fault alarm will be output; if the static leakage rate is not higher than the system's allowable error threshold, the venting calculation module will be enabled.

8. The blanket air permeability detection system based on intelligent sensors according to claim 4, characterized in that, The zero-pressure threshold range is set to ±0.5 Pascals; Configured to monitor the duration for which the pressure difference between the inner and outer chambers remains within the zero-pressure threshold range; If the duration exceeds the preset stability determination period, the air permeability calculation module is activated to perform data acquisition; if the duration does not exceed the preset stability determination period, the system remains in a waiting state to ensure that the acquired data is entirely based on the vertical flow field.

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