A method for testing air permeability of ergonomic chairs

Abstract

This invention relates to the field of breathability testing technology, and more particularly to a method for testing the breathability of ergonomic chairs. The invention obtains a first airflow passage characteristic vector set for each surface area of ​​an ergonomic chair under non-simulated conditions and a second airflow passage characteristic vector set for each surface area under simulated conditions. Based on the comparison between the first and second airflow obstruction characteristic vectors, the method for simulating the testing state of each surface area is determined. The difference in airflow rate before and after the testing state simulation is used to determine whether the breathability of the surface area is abnormal. Thus, the method simulates the breathability of the surface fabric under different usage conditions, improving the accuracy of breathability testing for ergonomic chairs.

Description

Technical Field

[0001] This invention relates to the field of breathability testing technology, and in particular to a method for testing the breathability of an ergonomic chair. Background Technology

[0002] Ergonomic chairs provide users with a comfortable and healthy sitting experience, and breathability is one of the key factors affecting user comfort. In actual use, the breathability of ergonomic chairs is affected by various factors such as material properties, structural design, and stress conditions during use. Currently, the testing methods for the breathability of ergonomic chairs are relatively limited. Traditional testing methods may only focus on the breathability of the material itself, ignoring the changes in breathability under actual use. Different surface areas may be affected by different factors affecting breathability due to differences in structure and function. Existing testing methods cannot comprehensively and accurately assess the impact of these factors on breathability. More accurate assessment of the breathability of ergonomic chairs can provide strong support for product design optimization and quality control.

[0003] For example, Chinese Patent Publication No. CN118483141A discloses a method for testing the air permeability of fabrics. The specific steps are as follows: Step 1: Establish a fabric surface area change prediction model based on a neural network algorithm; Step 2: Place the fabric on a base plate and ensure it is flat; move the negative pressure chamber downwards and clamp the fabric between the negative pressure chamber and the base plate; extract air into the negative pressure chamber through an air extraction tube, and then calculate the measured air permeability K of the fabric; Step 3: Predict the change in surface area A after the fabric bulge change using the fabric surface area change prediction model, and calculate the correction coefficient; Step 4: Correct the measured air permeability K using the correction coefficient.

[0004] The following problems still exist in the existing technology:

[0005] Existing technologies do not take into account the impact of factors such as structure and stress on the breathability of the surface of ergonomic chairs in actual use. They cannot simulate the breathability of the surface fabric based on the sitting state, which affects the accuracy of breathability testing of ergonomic chairs under different usage conditions and makes it difficult to support product design optimization and quality control. Summary of the Invention

[0006] Therefore, the present invention provides a method for testing the breathability of an ergonomic chair, which overcomes the problem that the existing technology cannot simulate the breathability of the surface fabric according to the sitting state, thus affecting the accuracy of the breathability test of the ergonomic chair under different usage conditions.

[0007] To achieve the above objectives, the present invention provides a method for testing the breathability of an ergonomic chair, comprising:

[0008] Obtain the first airflow passage representation vector set of each surface area of ​​the ergonomic chair in the non-simulated state on the sitting surface and the sitting back. Determine the first airflow obstruction representation quantity based on the angle between the vectors in the first airflow passage representation vector set. Obtain the second airflow passage representation vector set of each surface area of ​​the ergonomic chair in the simulated state on the sitting surface and the sitting back. Determine the second airflow obstruction representation quantity based on the angle between the vectors in the second airflow passage representation vector set.

[0009] The air permeability interference category of each surface region is determined based on the comparison between the first airflow obstruction characterization value and the second airflow obstruction characterization value.

[0010] The method for simulating the detection state of each surface region is determined based on the air permeability interference category corresponding to each surface region, including:

[0011] A continuous, preset simulation duration of opposite tension is applied along the seating surface and the back of the seating area, respectively.

[0012] Alternatively, apply a pressing force in opposite directions for the duration of the preset simulation to the seating surface and the back of the seating area that is perpendicular to the surface region;

[0013] The air permeability of each surface area is obtained before and after the detection state simulation, and the air permeability of the surface area is determined to be abnormal based on the difference in air permeability before and after the detection state simulation.

[0014] Furthermore, the process of obtaining the first airflow crossing representation vector set includes:

[0015] Acquire surface point cloud data of the ergonomic chair in a non-simulated state to construct a first surface contour model;

[0016] The first surface contour model is divided into several surface regions;

[0017] Based on the point cloud data of each surface region, the unit normal vector of the seating surface and the unit normal vector of the seating back are determined, and the vector set composed of the unit normal vector of the seating surface and the unit normal vector of the seating back is determined as the first airflow crossing characterization vector set.

[0018] Furthermore, the first airflow obstruction characterization quantity is the vector angle between the unit normal vector of the seating surface and the unit normal vector of the seating back surface within the first airflow passage characterization vector set.

[0019] Furthermore, the process of obtaining the second airflow crossing characterization vector set includes:

[0020] Acquire surface point cloud data of the ergonomic chair under simulated conditions to construct a second surface contour model;

[0021] The second surface contour model is divided into several surface regions;

[0022] Based on the point cloud data of each surface region, the unit normal vector of the seating surface and the unit normal vector of the seating back are determined, and the vector set composed of the unit normal vector of the seating surface and the unit normal vector of the seating back is determined as the second airflow crossing characterization vector set.

[0023] Furthermore, the second airflow obstruction characterization quantity is the vector angle between the unit normal vector of the seating surface and the unit normal vector of the seating back surface within the second airflow passage characterization vector set.

[0024] Furthermore, the comparison between the first airflow obstruction characterization and the second airflow obstruction characterization is determined based on the air permeability interference characterization.

[0025] The air permeability interference characterization quantity is the difference between the first airflow obstruction characterization quantity and the second airflow obstruction characterization quantity.

[0026] Furthermore, the process of determining the permeability interference category of the surface area includes:

[0027] If the air permeability interference characterization quantity meets the condition of pore distortion dominance, then the air permeability interference category of the surface region is determined to be the pore distortion feature dominance category;

[0028] If the air permeability interference characterization quantity does not meet the condition of dominant pore distortion, then the air permeability interference category of the surface region is determined to be the non-dominant category of pore distortion feature.

[0029] The condition for the manifestation of pore distortion is that the air permeability interference characterization quantity exceeds the preset air permeability interference characterization threshold.

[0030] Furthermore, the methods for simulating the detection state include:

[0031] If the air permeability interference category of the surface area is the dominant category of pore distortion feature, then the method of simulating the detection state is determined to be to apply a continuous preset simulation duration and opposite direction of tension along the seating surface and the seating back side parallel to the surface area, respectively.

[0032] If the air permeability interference category of the surface area is the non-obvious category of pore distortion feature, then the method of simulating the detection state is to apply a squeezing force in opposite directions for a continuous preset simulation duration along the seating surface and the seating back side perpendicular to the surface area.

[0033] Furthermore, the value of the tensile force applied to the surface area is positively correlated with the second airflow obstruction characterization value, and the value of the compressive force applied to the surface area is positively correlated with the second airflow obstruction characterization value.

[0034] Furthermore, determining whether the air permeability of the surface area is abnormal includes:

[0035] If the difference in air permeability rate before and after the simulated detection state meets the air permeability attenuation condition, then the air permeability of the surface area is determined to be normal.

[0036] If the difference in air permeability rate before and after the detection state simulation does not meet the air permeability attenuation condition, then the air permeability of the surface area is determined to be abnormal.

[0037] The air permeability attenuation condition is that the air permeability rate difference exceeds a preset air permeability rate attenuation reference value, and the air permeability rate is determined based on the gas flow rate per unit time.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention obtains the first airflow passage characterization vector set of each surface area of ​​the ergonomic chair in the non-simulated state and the second airflow passage characterization vector set of each surface area of ​​the ergonomic chair in the simulated state, and determines the air permeability interference category of each surface area based on the comparison between the first airflow obstruction characterization quantity and the second airflow obstruction characterization quantity. Based on the air permeability interference category, the method of simulating the detection state of each surface area is determined, and the air permeability of the surface area is determined based on the difference in air permeability rate before and after the detection state simulation. Thus, the air permeability state of the surface fabric is simulated according to the sitting state, thereby improving the detection accuracy of the air permeability of the ergonomic chair under different usage states.

[0039] Furthermore, by constructing a first surface contour model and a second surface contour model, this invention can comprehensively reflect the surface morphology of the ergonomic chair in both non-simulated and sitting states. Based on this, the first and second airflow passage characterization vector sets contain unit normal vector information for the sitting surface and the back of the chair in different states. It can be understood that dividing the surface contour model of the ergonomic chair into several surface regions before determining the unit normal vectors can fully consider the characteristic differences of different surface regions of the chair, and avoid the different influences that the shape, curvature, and other factors of different regions may have on airflow passage. Thus, the evaluation of the airflow obstruction status of each surface region covers multiple dimensions of features related to airflow passage.

[0040] Furthermore, by determining the difference between the first and second airflow obstruction characterization quantities as the air permeability interference characterization quantity, this invention can quantify the difference in airflow obstruction between the ergonomic chair in non-simulated and simulated states. When the calculated difference in the air permeability interference characterization quantity is large, it means that the angle between the unit normal vector of the seating surface and the back of the seating area changes significantly from the non-simulated state to the simulated state. A large change in angle may be due to the body generating a large lateral displacement or twisting motion on the chair surface fabric when sitting on the chair. These actions will cause a significant change in the fiber structure of the fabric. The shape and distortion cause the original air permeability channels to also become distorted, changing the originally smooth airflow channels. The airflow is subject to greater obstruction, which ultimately affects the air permeability. When the difference in the air permeability interference characteristic quantity is small, it indicates that the angle between the unit normal vector of the sitting surface and the back of the sitting area does not change much from the non-simulated state to the simulated state. When a person sits on the chair, the main influence on the fabric surface may come from gravity. The fabric may be compressed, causing the air permeability channels to narrow or even be partially blocked. Thus, the air permeability of the surface fabric can be quantitatively distinguished according to the sitting state.

[0041] Furthermore, by determining the relationship between the air permeability interference characterization quantity and the preset air permeability interference characterization threshold, the present invention classifies the air permeability interference category of the surface area into a dominant category of pore distortion characteristics and a non-dominant category of pore distortion characteristics. By accurately judging and classifying the air permeability interference category of the surface area, the ergonomic chair can more accurately match the actual working conditions in the testing process, realizing the simulation of the air permeability state of the surface fabric according to the sitting state, and improving the detection accuracy of the air permeability of the ergonomic chair under different usage states.

[0042] Furthermore, this invention selects a targeted detection state simulation method based on the type of air permeability interference. For different types of air permeability interference, different detection state simulation methods are selected. For the type of obvious pore distortion characteristics, since the change in air permeability in this area is mainly affected by the pore distortion caused by lateral movement, a tension force is applied parallel to the surface to simulate the effect of lateral displacement on the fabric when the human body changes posture. For the type of indistinct pore distortion characteristics, since the air permeability problem in this category is mainly caused by the blockage of air permeability channels due to gravity, a vertical extrusion force is applied to simulate the compaction effect of gravity on the fabric. Thus, the air permeability of the surface fabric can be simulated according to the sitting state, improving the detection accuracy of the air permeability of the ergonomic chair under different usage states.

[0043] Furthermore, this invention establishes a positive correlation between the magnitude of tensile and compressive forces and the second airflow obstruction characterization quantity, which makes the simulation conditions closer to the actual situation and avoids distortion of the test results due to excessive or insufficient force. Thus, it realizes the simulation of the air permeability of the surface fabric according to the sitting state, and improves the detection accuracy of the air permeability of the ergonomic chair under different usage states. Attached Figure Description

[0044] Figure 1 This is a step diagram illustrating the method for testing the breathability of an ergonomic chair according to an embodiment of the present invention;

[0045] Figure 2 This is a diagram illustrating the steps of obtaining the first airflow crossing characterization vector set in an embodiment of the present invention;

[0046] Figure 3 This is a diagram illustrating the steps of obtaining the second airflow crossing characterization vector set in an embodiment of the present invention;

[0047] Figure 4 A logic flowchart for determining the air permeability interference category of a surface region in an embodiment of the present invention;

[0048] Figure 5 This is a flowchart illustrating the logic of determining whether the air permeability of a surface area is abnormal, according to an embodiment of the present invention. Detailed Implementation

[0049] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0050] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0051] It should be noted that in the description of this invention, the terms "upper," "lower," "inner," "outer," etc., which indicate the direction or positional relationship, are based on the direction or positional relationship shown in the drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0052] Please see Figure 1 The diagram shows the steps of the ergonomic chair breathability testing method according to an embodiment of the present invention. The ergonomic chair breathability testing method of the present invention includes:

[0053] Step S100: Obtain the first airflow passage representation vector set of each surface area of ​​the ergonomic chair in the non-simulated state on the sitting surface and the sitting back; determine the first airflow obstruction representation quantity based on the angle between the vectors in the first airflow passage representation vector set; obtain the second airflow passage representation vector set of each surface area of ​​the ergonomic chair in the simulated state on the sitting surface and the sitting back; determine the second airflow obstruction representation quantity based on the angle between the vectors in the second airflow passage representation vector set.

[0054] In practice, cameras can be used to capture and record data on the head, shoulders, elbows, wrists, hips, knees, and ankles of the human body in a natural sitting posture. This data can be used to record various movements and postures, and then applied to the simulation of an ergonomic chair. This allows the chair's state to match the actual human body's forward tilting, backward tilting, and side tilting postures. Further details will not be elaborated here.

[0055] Step S200: Determine the air permeability interference category of each surface region based on the comparison between the first airflow obstruction characterization value and the second airflow obstruction characterization value;

[0056] Step S300: Based on the air permeability interference category corresponding to each surface region, determine the method for simulating the detection state of each surface region, including:

[0057] A continuous, preset simulation duration of opposite tension is applied along the seating surface and the back of the seating area, respectively.

[0058] Alternatively, apply a pressing force in opposite directions for the duration of the preset simulation to the seating surface and the back of the seating area that is perpendicular to the surface region;

[0059] Specifically, the preset simulation duration can be determined by those skilled in the art based on the requirements of detection accuracy. When the fabric durability of the surface area meets the standard, the longer the duration of applying tension and compression, the more obvious the impact of riding on the fabric in each surface area. In this invention, the preset simulation duration ranges from 3 to 12 hours, and preferably, the preset simulation duration is 8 hours.

[0060] Step S400: Obtain the air permeability rate of each surface area before and after the detection state simulation, and determine whether the air permeability of the surface area is abnormal based on the difference in air permeability rate before and after the detection state simulation.

[0061] Specifically, the seating surface of an ergonomic chair is the surface area that directly contacts the main parts of the human body, such as the buttocks and back, while the back of the chair refers to the surface area on the opposite side of the seating surface that does not directly contact the main parts of the human body, such as the buttocks and back.

[0062] Specifically, please refer to Figure 2The diagram illustrates the steps of obtaining the first airflow crossing characterization vector set according to an embodiment of the present invention. The process of obtaining the first airflow crossing characterization vector set includes:

[0063] Step S101: Obtain surface point cloud data of the ergonomic chair in a non-simulated state to construct a first surface contour model;

[0064] Step S102: Divide the first surface contour model into several surface regions;

[0065] Step S103: Determine the unit normal vector A1 of the seating surface and the unit normal vector A2 of the seating back surface based on the point cloud data of each surface region, and determine the vector set composed of the unit normal vector of the seating surface and the unit normal vector of the seating back surface as the first airflow crossing characterization vector set {A1, A2}.

[0066] Specifically, the unit normal vector A1 of the seating surface starts on the seating surface and ends at a point in the direction away from the ground. Similarly, the unit normal vector A2 of the back of the seating surface starts on the seating surface and ends at a point in the direction away from the ground.

[0067] In practice, the unit normal vectors of the seating surface and the rear of the seating area can be determined based on a plane fitting method. First, the acquired point cloud data is preprocessed by denoising and filtering to remove possible noise points and outliers. The plane is then fitted using methods such as the least squares method. The unit normal vectors of the seating surface and the rear of the seating area are then determined based on the coefficients of the plane equation, and the final unit normal vector is determined. The denoising and filtering of the point cloud data, the plane fitting using the least squares method, and the determination of the plane's normal vectors are existing technologies and will not be elaborated here.

[0068] Specifically, the first airflow obstruction characterization quantity is the vector angle between the unit normal vector of the seating surface and the unit normal vector of the seating back surface within the first airflow passage characterization vector set.

[0069] In practice, the unit normal vector A1 of the seating surface and the unit normal vector A2 of the rear seating surface are obtained. The cosine value of the vector angle is calculated according to the vector dot product formula. The inverse trigonometric function is used to determine the vector angle between the unit normal vector of the seating surface and the unit normal vector of the rear seating surface. This is existing technology and will not be described in detail here.

[0070] Specifically, please refer to Figure 3 The diagram illustrates the steps of obtaining the second airflow crossing characterization vector set according to an embodiment of the present invention. The process of obtaining the second airflow crossing characterization vector set includes:

[0071] Step S111: Obtain surface point cloud data of the ergonomic chair in a simulated state to construct a second surface contour model;

[0072] Step S112: Divide the second surface contour model into several surface regions;

[0073] Step S113: Determine the unit normal vector B1 of the seating surface and the unit normal vector B2 of the seating back surface based on the point cloud data of each surface region, and determine the vector set composed of the unit normal vector of the seating surface and the unit normal vector of the seating back surface as the second airflow crossing characterization vector set {B1, B2}.

[0074] Specifically, the unit normal vector A1 of the seating surface starts on the seating surface and ends at a point in the direction away from the ground. Similarly, the unit normal vector A2 of the back of the seating surface starts on the seating surface and ends at a point in the direction away from the ground.

[0075] In implementation, point cloud data of the ergonomic chair surface can be acquired using a 3D laser scanner. The unit normal vector of the seating surface and the unit normal vector of the back of the seating area in the simulated state can be determined based on a plane fitting method. First, the acquired point cloud data is preprocessed by denoising and filtering to remove possible noise points and outliers. The plane is then fitted using methods such as the least squares method. Then, the unit normal vector of the seating surface and the normal vector of the back of the seating area are determined based on the coefficients of the plane equation, and the final unit normal vector is determined. The denoising and filtering of the point cloud data, the plane fitting by the least squares method, and the determination of the plane normal vector are existing technologies and will not be elaborated here.

[0076] Specifically, the second airflow obstruction characterization quantity is the vector angle between the unit normal vector of the seating surface and the unit normal vector of the seating back surface within the second airflow passage characterization vector set.

[0077] In practice, the unit normal vector B1 of the seating surface and the unit normal vector B2 of the rear seating surface are obtained. The cosine value of the vector angle is calculated according to the vector dot product formula. The inverse trigonometric function is used to determine the vector angle between the unit normal vector of the seating surface and the unit normal vector of the rear seating surface. This is existing technology and will not be described in detail here.

[0078] Specifically, this invention, by constructing a first surface contour model and a second surface contour model, can comprehensively reflect the surface morphology of the ergonomic chair in both non-simulated and sitting states. Based on this, the first and second airflow passage characterization vector sets contain unit normal vector information for the sitting surface and the back of the chair in different states. It can be understood that dividing the surface contour model of the ergonomic chair into several surface regions before determining the unit normal vectors can fully consider the characteristic differences of different surface regions of the chair, and avoid the different influences that the shape, curvature, and other factors of different regions may have on airflow passage. Thus, the evaluation of the airflow obstruction status of each surface region covers multiple dimensions of features related to airflow passage.

[0079] Specifically, the comparison between the first airflow obstruction characterization and the second airflow obstruction characterization is determined based on the air permeability interference characterization.

[0080] The air permeability interference characterization quantity is the difference between the first airflow obstruction characterization quantity and the second airflow obstruction characterization quantity.

[0081] Specifically, this invention quantifies the difference between the first and second airflow obstruction characterization quantities as the air permeability interference characterization quantity. This allows for the quantification of the difference in airflow obstruction between the ergonomic chair in non-simulated and simulated states. When the calculated difference in the air permeability interference characterization quantity is large, it means that the angle between the unit normal vector of the seating surface and the backrest changes significantly from the non-simulated state to the simulated state. This large angle change may be due to significant lateral displacement or twisting of the body on the chair surface fabric when sitting on the chair. These actions cause a significant change in the fiber structure of the fabric. The shape and distortion cause the original air permeability channels to also become distorted, changing the originally smooth airflow channels. The airflow is subject to greater obstruction, which ultimately affects the air permeability. When the difference in the air permeability interference characteristic quantity is small, it indicates that the angle between the unit normal vector of the sitting surface and the back of the sitting area does not change much from the non-simulated state to the simulated state. When a person sits on the chair, the main influence on the fabric surface may come from gravity. The fabric may be compressed, causing the air permeability channels to narrow or even be partially blocked. Thus, the air permeability of the surface fabric can be quantitatively distinguished according to the sitting state.

[0082] Specifically, please refer to Figure 4 As shown, it is a logic flowchart for determining the air permeability interference category of a surface area according to an embodiment of the present invention. The process of determining the air permeability interference category of a surface area includes:

[0083] If the air permeability interference characterization quantity meets the condition of pore distortion dominance, then the air permeability interference category of the surface region is determined to be the pore distortion feature dominance category;

[0084] If the air permeability interference characterization quantity does not meet the condition of dominant pore distortion, then the air permeability interference category of the surface region is determined to be the non-dominant category of pore distortion feature.

[0085] The condition for the manifestation of pore distortion is that the air permeability interference characterization quantity exceeds the preset air permeability interference characterization threshold.

[0086] In practice, a large number of breathability performance experiments were conducted on the ergonomic chair fabric under various conditions such as different pressures and sitting postures. Data on breathability interference characteristics were collected, and the distribution and variation patterns of the data were analyzed to find a critical value that can clearly distinguish whether pore distortion dominates breathability interference. In this invention, the preset breathability interference characterization threshold range is [25°, 35°], and preferably, the preset breathability interference characterization threshold is 30°.

[0087] Specifically, this invention determines the relationship between the air permeability interference characterization quantity and the preset air permeability interference characterization threshold, and divides the air permeability interference category of the surface area into a dominant category of pore distortion characteristics and a non-dominant category of pore distortion characteristics. By accurately judging and classifying the air permeability interference category of the surface area, the ergonomic chair can more accurately match the actual working conditions in the testing process, realize the simulation of the air permeability state of the surface fabric according to the sitting state, and improve the detection accuracy of the air permeability of the ergonomic chair under different usage states.

[0088] Specifically, the methods for determining the simulation of the detection state include:

[0089] If the air permeability interference category of the surface area is the dominant category of pore distortion feature, then the method of simulating the detection state is determined to be to apply a continuous preset simulation duration and opposite direction of tension along the seating surface and the seating back side parallel to the surface area, respectively.

[0090] If the air permeability interference category of the surface area is the non-obvious category of pore distortion feature, then the method of simulating the detection state is to apply a squeezing force in opposite directions for a continuous preset simulation duration along the seating surface and the seating back side perpendicular to the surface area.

[0091] Specifically, the sample to be tested can be mounted on a hydraulically controlled fixture, which then contacts and fixes the seat surface and the back of the seat. Test parameters, including tensile force and preset simulation duration, are set. The hydraulic controller is then activated, and the fixture applies the corresponding tensile force according to the set parameters. The measurement and control system monitors the tensile force and duration in real time to ensure that the tensile force is parallel to the seat surface and the back of the seat, and that the duration reaches the preset simulation duration. Similarly, the fixture can also contact the seat surface and the back of the seat, and test parameters, including compressive force and preset simulation duration, are set. The hydraulic controller is then activated, and the fixture applies the corresponding compressive force according to the set parameters. The measurement and control system monitors the compressive force and duration in real time to ensure that the compressive force is perpendicular to the seat surface and the back of the seat, and that the duration reaches the preset simulation duration. This is existing technology and will not be elaborated further here.

[0092] Specifically, this invention selects a targeted detection state simulation method based on the type of air permeability interference. For different types of air permeability interference, different detection state simulation methods are selected. For the type of obvious pore distortion characteristics, since the change in air permeability in this area is mainly affected by pore distortion caused by lateral movement, a tension force is applied parallel to the surface to simulate the effect of lateral displacement on the fabric when the human body changes posture. For the type of indistinct pore distortion characteristics, since the air permeability problem in this category is mainly caused by the blockage of air permeability channels due to gravity, a vertical extrusion force is applied to simulate the compaction effect of gravity on the fabric. Thus, the air permeability of the surface fabric can be simulated according to the sitting state, improving the detection accuracy of the air permeability of the ergonomic chair under different usage states.

[0093] Specifically, the value of the tensile force applied to the surface area is positively correlated with the second airflow obstruction characterization value, and the value of the compressive force applied to the surface area is positively correlated with the second airflow obstruction characterization value.

[0094] Specifically, this invention establishes a positive correlation between the magnitude of tensile and compressive forces and the second airflow obstruction characterization quantity, which makes the simulation conditions closer to the actual situation and avoids the distortion of test results due to excessive or insufficient force. Thus, it realizes the simulation of the air permeability of the surface fabric according to the sitting state, and improves the detection accuracy of the air permeability of the ergonomic chair under different usage states.

[0095] Specifically, please refer to Figure 5 As shown, this is a flowchart illustrating the logic of determining whether the air permeability of a surface area is abnormal according to an embodiment of the present invention. Determining whether the air permeability of a surface area is abnormal includes:

[0096] If the difference in air permeability rate before and after the simulated detection state meets the air permeability attenuation condition, then the air permeability of the surface area is determined to be normal.

[0097] If the difference in air permeability rate before and after the detection state simulation does not meet the air permeability attenuation condition, then the air permeability of the surface area is determined to be abnormal.

[0098] The air permeability attenuation condition is that the air permeability rate difference exceeds a preset air permeability rate attenuation reference value, and the air permeability rate is determined based on the gas flow rate per unit time.

[0099] Specifically, by conducting air permeability rate tests on a large number of samples of different materials, collecting air permeability rate data before and after the test conditions were simulated, and performing statistical analysis, the reference value for air permeability rate attenuation for general fabric materials or common seat breathable materials may be 50-100 cm⁻¹. 3 / min, preferably, the preset air permeability rate decay reference value is 70cm. 3 / min, for some high-performance breathable materials, the reference value for air permeability rate decay may be set at 30-60cm. 3 / min, preferably, the preset air permeability rate decay reference value is 45cm. 3 / min.

[0100] In practice, the air permeability tester can be used to obtain the air permeability rate of each surface area before and after the test state simulation. The air permeability tester is usually composed of an air source chamber, a flow monitoring system, a timer, and a data processing system. The air source chamber provides a stable airflow. When testing the air permeability rate, a quantitative amount of gas in the air source chamber is passed through the fabric of each surface area. The flow monitoring system determines the gas flow rate of the gas in the air source chamber through the fabric of the surface area per unit time. The data processing system determines the air permeability rate by the ratio of gas loss to unit time.

[0101] Specifically, the present invention can also issue an alarm prompt using devices such as alarm buzzers based on the determination result of abnormal air permeability of the surface area. Alarm buzzers are widely used in industrial process production and finished product inspection, and will not be elaborated here.

[0102] The implementation carrier of the embodiments of the present invention may specifically be a chip, component or module. The chip includes a processor and a memory connected together. The memory is used to store instructions. When the processor calls and executes the instructions, the chip can execute the ergonomic chair breathability testing method provided in the above embodiments. This embodiment also provides a readable storage medium that stores computer program code. When the computer program code is run on a computer, the computer executes the above-mentioned related method steps to implement the ergonomic chair breathability testing method provided in the above embodiments.

[0103] The technical solution of the present invention has been described above with reference to 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 can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

[0104] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for testing the air permeability of an ergonomic chair, characterized in that, include: Obtain the first airflow passage representation vector set of each surface area of ​​the ergonomic chair in the non-simulated state on the sitting surface and the sitting back. Determine the first airflow obstruction representation quantity based on the angle between the vectors in the first airflow passage representation vector set. Obtain the second airflow passage representation vector set of each surface area of ​​the ergonomic chair in the simulated state on the sitting surface and the sitting back. Determine the second airflow obstruction representation quantity based on the angle between the vectors in the second airflow passage representation vector set. The air permeability interference category of each surface region is determined based on the comparison between the first airflow obstruction characterization value and the second airflow obstruction characterization value. The method for simulating the detection state of each surface region is determined based on the air permeability interference category corresponding to each surface region, including: A continuous, preset simulation duration of opposite tension is applied along the seating surface and the back of the seating area, respectively. Alternatively, apply a pressing force in opposite directions for the duration of the preset simulation to the seating surface and the back of the seating area that is perpendicular to the surface region; The air permeability of each surface area is obtained before and after the detection state simulation, and the air permeability of the surface area is determined to be abnormal based on the difference in air permeability before and after the detection state simulation.

2. The method for testing the breathability of an ergonomic chair according to claim 1, characterized in that, The process of obtaining the first airflow crossing characterization vector set includes: Acquire surface point cloud data of the ergonomic chair in a non-simulated state to construct a first surface contour model; The first surface contour model is divided into several surface regions; Based on the point cloud data of each surface region, the unit normal vector of the seating surface and the unit normal vector of the seating back are determined, and the vector set composed of the unit normal vector of the seating surface and the unit normal vector of the seating back is determined as the first airflow crossing characterization vector set.

3. The method for testing the breathability of an ergonomic chair according to claim 2, characterized in that, The first airflow obstruction characterization quantity is the vector angle between the unit normal vector of the seating surface and the unit normal vector of the seating back surface within the first airflow passage characterization vector set.

4. The method for testing the breathability of an ergonomic chair according to claim 1, characterized in that, The process of obtaining the second airflow crossing characterization vector set includes: Acquire surface point cloud data of the ergonomic chair under simulated conditions to construct a second surface contour model; The second surface contour model is divided into several surface regions; Based on the point cloud data of each surface region, the unit normal vector of the seating surface and the unit normal vector of the seating back are determined, and the vector set composed of the unit normal vector of the seating surface and the unit normal vector of the seating back is determined as the second airflow crossing characterization vector set.

5. The method for testing the breathability of an ergonomic chair according to claim 4, characterized in that, The second airflow obstruction characterization quantity is the vector angle between the unit normal vector of the seating surface and the unit normal vector of the seating back surface within the second airflow passage characterization vector set.

6. The method for testing the breathability of an ergonomic chair according to claim 5, characterized in that, The comparison between the first airflow obstruction characterization and the second airflow obstruction characterization is determined based on the air permeability interference characterization; The air permeability interference characterization quantity is the difference between the first airflow obstruction characterization quantity and the second airflow obstruction characterization quantity.

7. The method for testing the breathability of an ergonomic chair according to claim 6, characterized in that, The process of determining the permeability interference category of a surface area includes: If the air permeability interference characterization quantity meets the condition of pore distortion dominance, then the air permeability interference category of the surface region is determined to be the pore distortion feature dominance category; If the air permeability interference characterization quantity does not meet the condition of dominant pore distortion, then the air permeability interference category of the surface region is determined to be the non-dominant category of pore distortion feature. The condition for the manifestation of pore distortion is that the air permeability interference characterization quantity exceeds the preset air permeability interference characterization threshold.

8. The method for testing the breathability of an ergonomic chair according to claim 7, characterized in that, The methods for determining the simulation of detection states include: If the air permeability interference category of the surface area is the dominant category of pore distortion feature, then the method of simulating the detection state is to apply a continuous preset simulation duration and opposite direction of tension along the seating surface and the seating back side parallel to the surface area. If the air permeability interference category of the surface area is the non-obvious category of pore distortion feature, then the method of simulating the detection state is to apply a squeezing force in opposite directions for a continuous preset simulation duration along the seating surface and the seating back side perpendicular to the surface area.

9. The method for testing the breathability of an ergonomic chair according to claim 8, characterized in that, The value of the tensile force applied to the surface area is positively correlated with the second airflow obstruction characterization value, and the value of the compressive force applied to the surface area is positively correlated with the second airflow obstruction characterization value.

10. The method for testing the breathability of an ergonomic chair according to claim 1, characterized in that, Determining whether the air permeability of a surface area is abnormal includes: If the difference in air permeability rate before and after the simulated detection state meets the air permeability attenuation condition, then the air permeability of the surface area is determined to be normal. If the difference in air permeability rate before and after the detection state simulation does not meet the air permeability attenuation condition, then the air permeability of the surface area is determined to be abnormal. The air permeability attenuation condition is that the air permeability rate difference exceeds a preset air permeability rate attenuation reference value, and the air permeability rate is determined based on the gas flow rate per unit time.

Images