Method and apparatus for testing seat vibration

Abstract

This invention discloses a method and apparatus for testing seat vibration. The method is applied to the apparatus for testing seat vibration. Two clearance openings are provided on the shoulder fabric on both sides of the seat. The apparatus includes: a vibrator disposed on the seat back and arranged within the clearance openings; a first sensor disposed within the clearance opening on the seat shoulder along the X direction of the seat back and close to the vibrator, the first sensor being used to excite the clearance openings; and a second sensor disposed within the clearance openings and close to the vibrator, the second sensor being used to record the excitation response. The method for testing seat vibration includes: exciting the seat and recording the excitation force and response signal; processing the excitation force and response signal data; calculating the damping ratio of the seat based on the processed excitation force and response signal data; and performing an arithmetic average based on the damping ratio. According to the embodiment of this invention, the method for testing seat vibration can evaluate the vibration comfort and stability of the seat.

Description

Technical Field

[0001] This invention relates to the field of automobile manufacturing technology, and more specifically, to a method and apparatus for testing seat vibration. Background Technology

[0002] Vibration of the car seat backrest along the fore-and-aft direction (X-axis of the vehicle coordinate system) is the primary direction affecting the comfort of drivers and passengers, while the magnitude of the vibration is the main factor in evaluating vibration. According to vibration theory, damping is the main parameter controlling vibration amplitude. Therefore, for seats, identifying the damping of the backrest in the X-axis is an important factor in evaluating the seat's vibration attenuation level, thus, there is room for improvement. Summary of the Invention

[0003] The present invention aims to at least solve one of the technical problems existing in the prior art. Therefore, the first objective of the present invention is to provide a method for testing seat vibration, which can evaluate the vibration comfort and stability of the seat.

[0004] A second objective of this invention is to provide a device for testing seat vibration.

[0005] The first aspect of the present invention provides a method for testing seat vibration, wherein the method for testing seat vibration is applied to a device for testing seat vibration, wherein two clearance openings are provided on the shoulder fabric on both sides of the seat, and the device includes: a vibrator, wherein the vibrator is disposed on the seat back and arranged in the clearance openings;

[0006] A first sensor is disposed in the clearance opening of the seat shoulder along the X direction of the seat back and close to the vibrator, wherein the first sensor is used to excite the clearance opening.

[0007] A second sensor is located inside the clearance opening and close to the exciter, wherein the second sensor is used to record the excitation response;

[0008] The method for testing seat vibration includes:

[0009] A motivational seat that records motivational force and response signals;

[0010] Process the excitation force and response signal data;

[0011] The damping ratio of the seat is calculated based on the processed excitation force and response signal data;

[0012] Calculate the arithmetic mean based on the damping ratio.

[0013] According to one embodiment of the present invention, the excitation output signal type is white noise, and the duty cycle is set to 65%.

[0014] According to one embodiment of the present invention, the excitation force and response signal are recorded twice.

[0015] In some embodiments, based on the recorded two response signals and excitation force, an amplitude-frequency curve is obtained and divided to obtain two frequency response function curves. At 0.707 times the resonance peak value on either of the two frequency response function curves, a straight line parallel to the frequency axis is drawn, intersecting the resonance curve at two points. The abscissa frequency values ​​corresponding to these two points are f1 and f2, respectively. The frequency value corresponding to the resonance peak is f, and Δf is the difference between f2 and f1. The damping ratio is calculated according to the half-power bandwidth method of the transfer function.

[0016]

[0017] A second aspect of the present invention provides an apparatus for testing seat vibration, wherein two clearance openings are provided in the fabric on both sides of the seat shoulder area, and the apparatus includes: a vibrator disposed on the seat back and arranged within the clearance openings.

[0018] A first sensor is disposed in the clearance opening of the seat shoulder along the X direction of the seat back and close to the vibrator, wherein the first sensor is used to excite the clearance opening.

[0019] A second sensor is located inside the clearance opening and close to the exciter, wherein the second sensor is used to record the excitation response.

[0020] According to one embodiment of the present invention, the seat is elastically connected to the vibrator.

[0021] According to one embodiment of the present invention, the height between the center point of the middle position of the seat back and the predetermined horizontal plane is 600±5mm.

[0022] According to one embodiment of the present invention, the clearance opening is a square, wherein the length is 20mm, the width is 10mm, and the height is 10mm.

[0023] According to one embodiment of the present invention, the seat headrest is adjusted to the middle position.

[0024] According to one embodiment of the present invention, the angle between the seat back and the seat cushion is 120±5°.

[0025] The method for testing seat vibration according to embodiments of the present invention calculates the damping ratio of the seat by exciting the seat and recording the excitation force and response signal. This method can evaluate the vibration comfort and stability of the seat. The device employs two sensors, one for exciting the opening and the other for recording the excitation response, ensuring test accuracy. Through the overall program design of the test object, boundaries, test parameter settings, and data processing, seat vibration testing is achieved conveniently and accurately. It does not require a dedicated vibration table, utilizes random signal excitation, has a continuous spectrum, and can simultaneously excite the specimen at all frequencies, simulating the effects of actual environmental vibration and realistically reflecting the product's response to the vibration environment. By obtaining relevant parameters from the obtained frequency response curve, the required damping ratio can be calculated.

[0026] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0027] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0028] Figure 1 This is a schematic diagram of the structure of a device for testing seat vibration according to an embodiment of the invention;

[0029] Figure 2 This is a schematic diagram of the frequency and amplitude parameters;

[0030] Figure 3 This is a flowchart illustrating a method for testing seat vibration according to an embodiment of the present invention.

[0031] Figure label:

[0032] Seat 100, clearance 101, seat cushion 102, seat back 103.

[0033] Device 200, vibrator 201, first sensor 202, second sensor 203. Detailed Implementation

[0034] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0035] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] The following is combined Figures 1-3 This describes a method for testing the vibration of a seat 100 according to an embodiment of the present invention.

[0038] like Figure 1 As shown, the first aspect of this disclosure proposes a method for testing the vibration of a seat 100. The method for testing the vibration of the seat 100 is applied to a device for testing the vibration of the seat 100. Two clearance openings 101 are provided on the shoulder fabric on both sides of the seat 100. The device 200 includes a vibrator 201, which is disposed on the seat back 103 and arranged in the clearance openings 101.

[0039] The device 200 further includes a first sensor 202, which is located in the clearance opening 101 of the seat shoulder along the X direction of the seat back 103 and close to the vibrator 201. The first sensor 202 is used to excite the clearance opening 101 in order to measure the magnitude and direction of the force borne by the seat during vibration, determine the installation position of the vibrator 201, and enable it to accurately transmit vibration signals.

[0040] The device 200 also includes a second sensor 203, which is located inside the clearance opening 101 and close to the exciter 201. The second sensor 203 is used to record the excitation response. In order to measure the acceleration of the seat during vibration, and to determine the vibration frequency and amplitude, as well as the performance of the seat during vibration, the second sensor 203 is a vibration acceleration sensor. By placing the vibration acceleration sensor on both sides of the shoulder area of ​​the seat back, the condition of the seat during vibration can be measured more accurately, and a more comfortable seat design can be provided to customers.

[0041] The purpose of arranging vibration exciters 201 on both sides of the shoulder area behind the seat is to simulate the impact of road and vehicle body vibrations on the seat during vehicle operation, thereby testing seat vibration. A first sensor 202, a force sensor, is installed around the vibration exciter 201 to measure the force applied to the seat by the vibration exciter 201 and feed the data back to the testing equipment for analysis. This installation ensures that the vibration exciter 201 can accurately apply force and allows for more accurate analysis and evaluation of the test data.

[0042] Meanwhile, the reason for installing the vibrator 201 within the two clearance openings 101 on the shoulder area of ​​the seat back is to better simulate the vibration experienced by the seat during vehicle movement, as the seat back is affected by lateral and rearward vibrations during vehicle movement. By arranging the vibrator 201 on both sides of the shoulder area and installing force sensors, the seat vibration can be measured more accurately, thereby improving the comfort and safety performance of the seat.

[0043] like Figure 3 As shown, the methods for testing seat vibration include:

[0044] S01 motivational chair, records motivational force and response signals;

[0045] The reason for recording the excitation force and response signal when testing seat vibration is to evaluate the seat's vibration performance and comfort. The excitation force is used to induce vibration in the seat, and the response signal is used to record the seat's vibration response.

[0046] S02 processes excitation force and response signal data;

[0047] The purpose of processing excitation and response signal data is to extract useful information, such as vibration frequency, amplitude, and phase, in order to analyze the vibration characteristics of the seat and optimize its design.

[0048] S03 calculates the seat's damping ratio based on the processed excitation force and response signal data;

[0049] By calculating the damping ratio of a seat, its vibration damping capability can be evaluated. The higher the damping ratio, the smaller the seat's vibration response and the higher its comfort level.

[0050] S04 is calculated as an arithmetic mean based on the damping ratio.

[0051] The purpose of averaging the damping ratio is to reduce testing errors and improve data reliability.

[0052] According to one embodiment of the present invention, the excitation output signal type is white noise, and the duty cycle is set to 65%.

[0053] The excitation output signal is white noise to cover as much of the frequency range as possible, in order to test the vibration performance of the seat at different frequencies. The duty cycle is set to 65% to ensure signal stability and accuracy. White noise is a random signal with equal power spectral density, covering the entire frequency range and with all frequency components having equal amplitude.

[0054] The excitation force and response signal are set to a rectangular window, with the force amplitude set to 0.4±0.05N and the frequency range set to 5-30Hz, averaging over 50 cycles. These settings are configured within the built-in control interface of the vibrator 201.

[0055] According to one embodiment of the present invention, for comparative analysis, the force and response signal during the first excitation are recorded, and the excitation force and response signal are recorded again after a period of use. By comparing the two sets of recorded data, the vibration characteristics of the car seat during use can be understood, and the durability of the seat structure and materials can be evaluated. Furthermore, during seat vibration testing, the data needs to be repeated multiple times to ensure the accuracy and reliability of the test results; therefore, the excitation force and response signal are recorded twice.

[0056] In some embodiments, such as Figure 2 As shown in the diagram, the frequency and amplitude parameters are illustrated. Based on the recorded two response signals and excitation force, the amplitude-frequency curve is obtained and divided to obtain two frequency response function curves. At 0.707 times the resonance peak value on either of the two frequency response function curves, a straight line parallel to the frequency axis is drawn, intersecting the resonance curve at two points. The corresponding abscissa frequency values ​​of these two points are f1 and f2, respectively. The frequency value corresponding to the peak value of the resonance is f, and Δf is the difference between f2 and f1. The damping ratio is calculated using the half-power bandwidth method of the transfer function.

[0057]

[0058] The above tests are conducted to assess the vibration characteristics of car seats. This is primarily achieved by recording the excitation force and response signals to analyze the seat's frequency response curve and damping ratio. Calculating the damping ratio reveals the energy consumption of the seat during vibration, allowing for a determination of whether the vibration is appropriate and whether it may cause driver discomfort or safety hazards.

[0059] Taking the arithmetic mean of the two calculated damping ratios is to improve the accuracy of the calculation results. Because there may be some uncontrollable factors during the testing process, such as weather and personnel, the calculation results may contain some errors. Therefore, taking the average of the two calculation results can effectively reduce errors and improve the reliability of the calculation results.

[0060] A second aspect of the present invention provides a device 200 for testing seat vibration, wherein two clearance openings 101 are provided in the fabric on both sides of the seat shoulder area. The device 200 includes: a vibrator 201, which is disposed on the seat back 103 and arranged within the clearance openings 101.

[0061] It also includes: a first sensor 202, which is located in the clearance opening 101 of the seat shoulder along the direction of the seat back 103X and close to the vibrator 201, wherein the first sensor 202 is used to excite the clearance opening 101;

[0062] It also includes a second sensor 203, which is located inside the clearance opening 101 and close to the exciter 201, wherein the second sensor 203 is used to record the excitation response.

[0063] The purpose of arranging vibration exciters 201 on both sides of the shoulder area behind the seat is to simulate the impact of road and vehicle body vibrations on the seat during vehicle operation, thereby testing seat vibration. A first sensor 202, a force sensor, is installed around the vibration exciter 201 to measure the force applied to the seat by the vibration exciter 201 and feed the data back to the testing equipment for analysis. This installation ensures that the vibration exciter 201 can accurately apply force and allows for more accurate analysis and evaluation of the test data.

[0064] Meanwhile, the reason for installing the vibrator 201 within the two clearance openings 101 on the shoulder area of ​​the seat back is to better simulate the vibration experienced by the seat during vehicle movement, as the seat back is affected by lateral and rearward vibrations during vehicle movement. By arranging the vibrator 201 on both sides of the shoulder area and installing force sensors, the seat vibration can be measured more accurately, thereby improving the comfort and safety performance of the seat.

[0065] In some embodiments, the seat is elastically connected to the vibrator 201.

[0066] The vibrator 201 is suspended using an elastic boundary to ensure that the lower mode of the vibrator 201 is ≤5Hz at the free boundary. The force sensors are fixed along the X direction of the seat back 103 to the left and right clearance openings 101 on the shoulder of the seat, so as to excite the clearance openings 101 on both sides respectively.

[0067] The elastic connection between the seat and the vibrator 201 allows the vibration of the vibrator 201 to be effectively transmitted to the seat, ensuring the accuracy and reliability of the test.

[0068] In some embodiments, the distance of 600±5mm between the center point of the middle position of the seat back and the predetermined horizontal plane is determined by the standard specifications for the seat. Typically, the automotive seat industry has established several standard test procedures and requirements, including seat vibration testing, which specifies the necessary setup and measurement parameters for testing. One of these is the distance of 600±5mm between the center point of the middle position of the seat back and the predetermined horizontal plane. This distance is an optimal value derived from extensive testing and experimental research to ensure the accuracy and repeatability of the test results. Therefore, the height between the center point of the middle position of the seat back 103 and the predetermined horizontal plane is 600±5mm.

[0069] In some embodiments, the clearance opening 101 is a square shape, with a length of 20 mm, a width of 10 mm, and a height of 10 mm. This facilitates close alignment with the external dimensions of the force sensor to be placed, avoiding excessive size that could cause additional mass loss and thus affect the modal frequency.

[0070] In some embodiments, the seat headrest is adjusted to the middle position.

[0071] Adjusting the headrest to the middle position ensures accurate control of the exciter 201's position and the direction of the excitation force during testing, maximizing the simulation of real-world usage scenarios and thus improving test accuracy and reliability. Adjusting the headrest position also makes the test data more representative and simulates different user experiences, leading to more comprehensive and accurate results.

[0072] In some embodiments, the angle between the seat back 103 and the seat cushion 102 is 120±5°.

[0073] The angle between the seat back 103 and the seat cushion 102 is 120±5° to simulate a normal sitting posture and ensure both comfort and stability. The angle between the seat back 103 and the seat cushion should not be too large or too small. Too small an angle will make the occupant feel cramped, while too large an angle will reduce stability and comfort. Adjusting the angle appropriately allows the occupant to be in the optimal sitting posture, thus achieving the best comfort and stability.

[0074] The method for testing seat vibration according to embodiments of the present invention calculates the seat's damping ratio by exciting the seat and recording the excitation force and response signal, thereby evaluating the seat's vibration comfort and stability. The device 200200 employs two sensors, one for exciting the opening and the other for recording the excitation response, ensuring the accuracy of the test. Analysis of the method's effectiveness reveals that it can provide effective technical support for the research and development and production of automotive seats.

[0075] By designing a comprehensive program for testing the object, boundaries, test parameters, and data processing, seat vibration testing is achieved conveniently and accurately. It does not require a dedicated vibration table, utilizes random signal excitation, and has a continuous spectrum, enabling simultaneous excitation of the specimen at all frequencies. This simulates the effects of real-world environmental vibration, realistically reflecting the product's response to vibration. The required damping ratio can be calculated by obtaining relevant parameters from the obtained frequency response curve. This method breaks through the conventional identification and control of the seat system's natural frequency and transmissivity, evaluating the seat system's attenuation capability to excitation over a wide frequency range from the perspective of damping ratio. Currently, no other manufacturer applies this method.

[0076] Three different test objects were selected, and the test results were compared with the test results of a certain vibration table based on the current method. The results are shown in Table 1 below. The difference is less than 0.3%, which proves that the accuracy of the method in this invention can be demonstrated.

[0077]

[0078] Table 1

[0079] Based on the current method, three different personnel were selected to test and compare the same test object. All fixtures / samples were reinstalled and the test system was rebuilt. The test results are shown in Table 2 below: Based on the same sample, according to this method, the results obtained by the three different testers differed by only 0.1%, and the repeatability was guaranteed.

[0080]

[0081] Table 2

[0082] The method 100 for testing seat vibration according to an embodiment of the present invention, as well as other configurations and operations described herein, are known to those skilled in the art and will not be described in detail here. The vertical, horizontal, and front-back directions are defined as shown in the figures.

[0083] In the description of this invention, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features not in direct contact but through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature.

[0084] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0085] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method of testing a seat vibration, characterized by, The method for testing seat vibration is applied to a device for testing seat vibration. The seat has two clearance openings on the shoulder fabric on both sides. The device includes a vibrator, which is located on the seat back and arranged in the clearance openings. The first sensor is located in the clearance opening of the seat shoulder along the X direction of the seat back and close to the vibrator. A second sensor is located inside the clearance opening and close to the exciter, wherein the second sensor is used to record the excitation response; The method for testing seat vibration includes: A motivational seat that records motivational force and response signals; Process the excitation force and response signal data; The damping ratio of the seat is calculated based on the processed excitation force and response signal data; Calculate the arithmetic mean based on the damping ratio; According to the recorded two response signals and the exciting force, two frequency response function curves are obtained, at 0.707 times of the resonance peak value on any one of the two frequency response function curves, a straight line parallel to the frequency axis intersects the frequency response function curve at two points, the corresponding abscissa frequency values of the two points are f1 and f2, and the frequency value corresponding to the resonance peak top is f, and the difference between f2 and f1 is Δf, and the damping ratio is calculated according to the transfer function half-power bandwidth method: .

2. Apparatus for testing the vibration of a seat, for implementing the method for testing the vibration of a seat according to claim 1, characterized in that, The seat has two clearance openings on the shoulder fabric on both sides. The device includes a vibrator, which is located on the seat back and arranged within the clearance openings. The first sensor is located in the clearance opening of the seat shoulder along the X direction of the seat back and close to the vibrator. A second sensor is located inside the clearance opening and close to the exciter, wherein the second sensor is used to record the excitation response; The seat is elastically connected to the vibrator; The height between the center point of the middle position of the seat back and the predetermined horizontal plane is 600±5mm; The seat headrest is adjusted to the middle position; The angle between the seat back and the seat cushion is 120±5°.

3. The apparatus of claim 2, wherein The clearance is square in shape, with a length of 20mm, a width of 10mm, and a height of 10mm.

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