KR20160136697A - Apparatus and method for measuring distribution of dynamic stiffness and loss factor for dynamic comfort evaluation of seat - Google Patents

Abstract

According to one embodiment of the present invention, provided is an apparatus to measure dynamic stiffness and loss factor distribution for dynamic comfort evaluation for a seat capable of predicting an evaluation of comfort for a seat by analyzing the stiffness distribution and the loss factor distribution. The apparatus comprises: a vibrator to generate vibration; a rigid substrate installed in an upper part of the vibrator, and vibrated by operation of the vibrator in order to vibrate a seat placed on an upper part; a plurality of dummies arranged on an upper part of the seat, and respectively vibrated by vibration of the seat in accordance with the vibration of the rigid substrate; and a measurement unit including a first sensor installed in the rigid substrate to measure a first vibration signal in accordance with the vibration of the rigid substrate, and a second sensor installed in each dummy to measure a second vibration signal in accordance with the vibration transferred to each dummy, measuring a stiffness and a loss factor of the seat based on the first and the second vibration signal.

Description

[0001] APPARATUS AND METHOD FOR MEASURING DISTRIBUTION OF DYNAMIC STIFFNESS AND LOSS FACTOR FOR DYNAMIC COMFORT EVALUATION OF SEAT [0002]

Embodiments of the present invention are directed to an apparatus and method for measuring the dynamic stiffness and loss coefficient distribution of a seat for evaluating the dynamic comfort of a seat.

Recently, the automobile culture has been rapidly developed due to the increase of the leisure time of the individual and the improvement of the living standard. In other words, the automobile is moving beyond the simple means of transportation and becoming a living space for individuals or groups.

As such, as the time spent in the automobile increases, the tendency to emphasize the ride quality of passengers is spreading.

On the other hand, the degree of comfort of the seat is the standard of ride comfort of the vehicle. At this time, in order to more accurately predict the comfort of the seat, it is important to grasp the characteristics of the seat more accurately.

That is, through the strength of the vibration of the vehicle transmitted to the seat, the comfort of the seat felt by the occupant can be predicted.

However, in the case of a seat of a vehicle, a single value was used to evaluate the characteristics of the seat. Therefore, it is not possible to analyze the characteristics of the sheet through the evaluated data or analyze the factors to be considered in order to improve the comfort of the sheet.

Therefore, there is a need to develop a technique capable of estimating the comfort of the seat by analyzing the vibration characteristics of each part of the seat, and measuring the factors affecting the vibration characteristics of the seat.

Related art is disclosed in Japanese Patent Application Laid-Open No. 10-1996-0081325 (entitled " Vehicle vibration characteristics measuring device, published on October 7, 1998).

One embodiment of the present invention is a method for measuring the stiffness and loss coefficient of a sheet for each of a plurality of dummies arranged on a sheet and measuring the stiffness distribution and the loss coefficient distribution, An apparatus and method for measuring dynamic stiffness and loss coefficient distribution of a sheet are provided.

An embodiment of the present invention is an apparatus and method for measuring the dynamic stiffness and loss coefficient distribution of a seat for evaluating the dynamic comfort of a seat capable of predicting the comfort evaluation of the seat by analyzing the stiffness distribution and the loss coefficient distribution, to provide.

The problems to be solved by the present invention are not limited to the above-mentioned problem (s), and another problem (s) not mentioned can be clearly understood by those skilled in the art from the following description.

An apparatus for measuring a dynamic stiffness and a loss coefficient distribution of a seat for evaluating dynamic comfort of a seat according to an embodiment of the present invention includes: an oscillator for generating vibration; A rigid substrate mounted on the vibrator and vibrated by driving the vibrator to apply an exciter to the sheet disposed on the upper portion; A plurality of dummies arranged on the sheet and vibrating respectively by the vibrations of the rigid substrate; A first sensor installed on the rigid substrate and measuring a first vibration signal corresponding to the vibration of the rigid substrate, and a second sensor mounted on each of the plurality of dummies, And a measurement unit that measures a stiffness and a loss coefficient of the sheet based on the first and second vibration signals.

The measuring unit may measure the stiffness and the loss coefficient of the sheet by using a transfer function based on the first and second vibration signals.

Wherein the measurement unit calculates a mutual spectral density calculated based on a cross spectrum function of the power spectral density calculated based on the autocorrelation function of the second vibration signal and the first vibration signal and the second vibration signal, And the stiffness and loss coefficient of the sheet can be measured using the derived transfer function.

The measuring unit may measure the stiffness distribution and the loss coefficient distribution of the sheet by curve fitting the measured stiffness and loss coefficient at each of the plurality of dummies.

Wherein the measuring unit analyzes the stiffness distribution and the loss coefficient distribution measured for each sheet having different characteristics to calculate an index including an average value of the stiffness distribution and the loss coefficient distribution for each sheet, A regression equation relating to the dynamic characteristics of the sheet is derived using an index, and a subjective evaluation result on the comfort of the sheet can be predicted using the derived regression equation.

The index may further include a standard deviation calculated based on the maximum value and the minimum value of each of the stiffness distribution and the loss coefficient distribution.

The first and second sensors may include an accelerometer sensor.

An apparatus for measuring the dynamic stiffness and loss coefficient distribution of a seat for evaluating dynamic comfort of a seat according to another embodiment of the present invention includes an acquiring unit for acquiring an experimental measurement of complex stiffness for each of a plurality of dummies arranged on an upper portion of a seat; A comparison unit comparing the real and imaginary parts of each of the complex stiffness experimental measurements with a real part and an imaginary part of a theoretical transfer function modeled theoretically for each of the plurality of dummies; And a measuring section for measuring the stiffness and the loss coefficient of the sheet based on the comparison result.

Wherein the obtaining unit obtains a power spectral density calculated based on an autocorrelation function of a second vibration signal in accordance with the vibration of each of the plurality of dummies and a second vibration signal that is a reference vibration signal applied to the seat through the vibrator, Experimental measurements of the complex stiffness can be obtained using an experimental transfer function derived from the cross-spectral density calculated based on the cross-correlation function of the vibration signal.

The obtaining unit may obtain the theoretical transfer function by modeling the sheet with a spring, and analyzing the sheet and the plurality of dummies into a mass-spring system.

Wherein the comparison unit compares the real part of the experimental measurement with the real part of the theoretical transfer function for each of the plurality of dummies to derive a first relational expression having the stiffness as a variable and compares the imaginary part of the experimental measurement with the theoretical transfer function Deriving a second relational expression having the stiffness and the loss coefficient as parameters by comparing the imaginary part and deriving a solution of each of the variables from the simultaneous equations based on the first and second relational expressions, The solution of each of the above variables can be measured as the stiffness and loss coefficient of the sheet.

The measuring unit may measure the stiffness distribution and the loss coefficient distribution of the sheet by curve fitting the measured stiffness and loss coefficient at each of the plurality of dummies.

Wherein the measuring unit analyzes the stiffness distribution and the loss coefficient distribution measured for each sheet having different characteristics to calculate an index including an average value of each of the stiffness distribution and the loss coefficient distribution for each sheet, A regression equation relating to the dynamic characteristics of the sheet is derived using the index obtained by the regression equation, and the subjective evaluation result on the comfort of the sheet can be predicted using the derived regression equation.

The index may further include a standard deviation calculated based on the maximum value and the minimum value of each of the stiffness distribution and the loss coefficient distribution.

A dynamic stiffness and loss coefficient distribution measuring method for a seat for dynamic comfort evaluation of a seat according to an embodiment of the present invention is characterized in that in a dynamic stiffness and loss coefficient distribution measuring apparatus, Acquiring an experimental measurement of the temperature; Comparing the real and imaginary parts of each of the complex stiffness experimental measurements with a real part and an imaginary part of a theoretical transfer function modeled theoretically for each of the plurality of dummies; And measuring the stiffness and loss coefficient of the sheet based on the comparison result in the dynamic stiffness and loss coefficient distribution measuring apparatus.

The details of other embodiments are included in the detailed description and the accompanying drawings.

According to an embodiment of the present invention, the stiffness and loss coefficient of a sheet can be measured for each of a plurality of dummies arranged on the sheet, and the stiffness distribution and the loss coefficient distribution, which are dynamic characteristics of the sheet, can be measured.

According to one embodiment of the present invention, the evaluation of the comfort of the seat can be predicted by analyzing the stiffness distribution and the loss coefficient distribution which are dynamic characteristics of the seat.

According to one embodiment of the present invention, the dynamic characteristics of each sheet can be measured by measuring the stiffness and loss coefficient distribution corresponding to each of the plurality of dummies from the transfer function for each position of each of the plurality of dummies.

According to one embodiment of the present invention, the dynamic characteristics of each sheet can be measured by comparing the theoretical transfer function modeled theoretically for each of a plurality of dummies and an experimental measurement of complex stiffness for each of a plurality of dummies.

According to one embodiment of the present invention, it is possible to suggest an improvement direction for improving the comfort of the seat by objectively measuring the dynamic characteristics of the seat and comparing it with the dynamic comfort evaluation (subjective evaluation) of the seat.

1 is a front view illustrating a dynamic stiffness and loss coefficient distribution measuring apparatus for evaluating dynamic comfort of a seat according to an embodiment of the present invention.
2 is a view for explaining an apparatus for measuring dynamic stiffness and loss coefficient distribution of a seat for evaluating dynamic comfort of a seat according to another embodiment of the present invention.
Figs. 3A to 3C are graphs for explaining the stiffness distribution and the loss coefficient distribution measurement of the sheet by the curve fitting, according to an embodiment of the present invention. Fig.
4A and 4B are graphs for explaining the indexes of stiffness distribution and loss coefficient distribution for each sheet in one embodiment of the present invention.
Fig. 5 is a graph illustrating the prediction of the subjective evaluation result on the comfort of the seat using the regression equation in one embodiment of the present invention. Fig.
6 is a flowchart illustrating a method of measuring dynamic stiffness and loss coefficient distribution of a seat for evaluating dynamic comfort of a seat according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and / or features of the present invention, and how to accomplish them, will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a front view illustrating a dynamic stiffness and loss coefficient distribution measuring apparatus for evaluating dynamic comfort of a seat according to an embodiment of the present invention.

1, a dynamic stiffness and loss coefficient distribution measuring apparatus 100 for evaluating the dynamic comfort of a seat according to an embodiment of the present invention includes a vibrator 110, a rigid substrate 120, (130) and a measuring unit (140).

The vibrator 110 generates vibration to apply an excitation to the sheet 101 arranged on the upper side. Here, the vibrator 110 may serve to vibrate the seat 101 in place of the movement of the automobile.

For reference, the vibrator 110 can be driven by various operating methods such as a mechanical type, an electric type, and an electro-hydraulic type.

The rigid substrate 120 is installed on the upper portion of the vibrator 110 and vibrates by driving the vibrator 110 to apply an excitation to the upper portion of the sheet 101.

In other words, when the rigid substrate 120 is installed between the vibrator 110 and the sheet, when the vibration is generated by driving the vibrator 110, the vibration is transmitted to the sheet 101, The sheet 101 can be vibrated.

For reference, a vibration signal according to the vibration of the rigid substrate 120 can be used as a reference vibration signal for obtaining a vibration signal according to the vibration of the seat 101.

The plurality of dummies (130) are arranged on the top of the seat (101). At this time, the plurality of derby 130 may be arranged in an arrangement pattern of a predetermined pattern on the sheet 101.

The plurality of dummies 130 are oscillated by the vibrations of the rigid substrate 120, respectively. That is, the plurality of dummies 130 may be vibrated by receiving vibration applied to the seat 101 as the rigid substrate 120 vibrates.

Since the plurality of dummies 130 are uniformly arranged in the upper portion of the seat 101, the stiffness and the loss of the seat 101 may vary depending on the positions in which the plurality of dummies 130 are arranged The coefficient can be measured.

The measurement unit 140 may measure the vibration of the seat 120 using the reference vibration signal (first vibration signal) according to the vibration of the rigid board 120 and the second vibration signal corresponding to the vibration of each of the plurality of dummies 130, 101) can be measured.

For this, the measuring unit 140 may include a first sensor 142 and a second sensor 144.

The first sensor 142 is mounted on the rigid substrate 120 and measures a first vibration signal corresponding to the vibration of the rigid substrate 120.

At least one of the first sensor 142 and the second sensor 142 may be installed on the rigid substrate 120. The vibrating signal generated by vibrating the rigid substrate 120 by driving the vibrator 110, That is, the first vibration signal can be measured.

The first sensor 142 may be implemented as an accelerometer sensor. However, the first sensor 142 is not limited to the accelerometer sensor, but may be implemented by other types of sensors capable of measuring vibration signals.

The second sensor 144 is installed in each of the plurality of dummies 130 and measures a second vibration signal corresponding to the vibration transmitted to each of the plurality of dummies 130.

At this time, as the vibration of the seat 101 is transmitted to each of the plurality of dummies 130, the second sensor 144 detects a vibration signal generated by each of the plurality of dummies 130, that is, 2 Vibration signal can be measured.

The second sensor 144 may be implemented by an accelerometer sensor as in the case of the first sensor 142. Alternatively, the second sensor 144 may be implemented by other types of sensors capable of measuring a vibration signal in addition to the accelerometer sensor .

The measurement unit 140 measures the stiffness and loss coefficient of the sheet 101 based on the first and second vibration signals.

That is, the measuring unit 140 may measure the stiffness and loss coefficient of the sheet 101 using a transfer function TF based on the first and second vibration signals.

For this purpose, the measuring unit 140 may derive the transfer function based on the first and second vibration signals, and may calculate the stiffness and loss coefficient of the seat 101 using the derived transfer function, Can be measured for each position of the dummy (130).

Specifically, the measuring unit 140 may measure a power spectrum density, which is calculated based on an autocorrelation function of the second vibration signal, and a second vibration signal, which is a reference vibration signal, The transfer function TF is derived using a cross-spectrum density calculated based on a cross-correlation function of the first and second vibration signals, and using the derived transfer function TF The stiffness and the loss coefficient of the sheet 101 can be measured.

Here, the autocorrelation function can be calculated by the following equation (1).

[Equation 1]

Here, R _xx represents an autocorrelation function of the second vibration signal, x (t) represents the second vibration signal, τ represents an interval between times when x (t) is taken, and T represents time.

The power spectral density calculated based on the autocorrelation function can be calculated by the following equation (2).

&Quot; (2) "

Where S _xx is a power spectral density function based on the autocorrelation function of the second vibration signal, R _xx is an autocorrelation function of the second vibration signal, τ is an interval between times when x (t) is taken, .

The cross-correlation function can be calculated by the following equation (3).

&Quot; (3) "

Here, R _xf is a cross-correlation function of the first and second vibration signals, x (t) is the first vibration signal, f (t) is the second vibration signal, And T represents time.

The mutual spectral density calculated based on the cross-correlation function can be calculated by the following equation (4).

&Quot; (4) "

Where S _xf is a mutual spectral density function based on a cross-correlation function of the first and second vibration signals, R _xf is a cross-correlation function of the first and second vibration signals, and τ is a time And? Represents the frequency.

As described above, the transfer function TF can be expressed by the following equation (5) based on the equations (1) to (4).

&Quot; (5) "

That is, the transfer function TF can be calculated based on the mutual spectral density function and the power spectral density function.

The measurement unit 140 can measure the stiffness and loss coefficient of the sheet 101 from the complex stiffness calculated through the transfer function TF. Here, the complex stiffness may be composed of a real part corresponding to the stiffness and an imaginary part corresponding to the loss coefficient.

Therefore, the measuring unit 140 may measure a value corresponding to the real part of the complex stiffness as the stiffness of the seat 101 at a position corresponding to the dummy 130, and determine a value corresponding to the imaginary part of the complex stiffness Value as a loss coefficient for the sheet 101 at a position corresponding to the dummy 130. [

The measurement unit 140 can measure the stiffness distribution and the loss coefficient distribution of the sheet 101 by curve fitting the measured stiffness and loss coefficient at each of the plurality of dummies 130. Since the curve fitting corresponds to a generally widely used numerical analysis, a description thereof will be omitted in the present embodiment.

Hereinafter, stiffness distribution and loss coefficient distribution measurement of the sheet 101 by the curve fitting will be described with reference to FIGS. 3A to 3C.

First, referring to FIGS. 1 and 3A, the measuring unit 140 may perform curve fitting of numerical values of respective transfer functions with respect to the stiffness and loss coefficients measured in the plurality of dummies 130. FIG.

For example, it is assumed that the number of dummies 130 arranged on the sheet 101 is 15, and each number is assigned from 1 to 15. In this case, the measurement unit 140 may express the numerical values of the transfer functions measured at the dummy 130 of the 3, 6, 9, 12, and 15 by using curve fitting.

At this time, the measurement unit 140 may display the numerical values of the respective transfer functions in the frequency domain through the curve fitting. In other words, the measuring unit 140 may represent the numerical values of the respective transfer functions measured in each dummy 130 as frequency-dependent magnitude values.

Thus, according to one embodiment of the present invention, the magnitude of the transfer function for each position in which the plurality of dummies 130 are arranged can be confirmed in the frequency domain.

Next, referring to FIGS. 1, 3B and 3C, the measurement unit 140 can obtain a stiffness distribution and loss coefficient distribution corresponding to each of the plurality of dummies 130 from the curve-fitted transfer function have.

3B, the measurement unit 140 may represent the stiffness distributions corresponding to the plurality of dummy 130 in the frequency domain. As shown in FIG. 3C, the plurality of dummy 130 ) Can be represented in the frequency domain.

Accordingly, according to an embodiment of the present invention, the stiffness distribution and the loss coefficient distribution can be identified for each position in which the plurality of dummies 130 are arranged, and through the transfer function of each of the plurality of dummies 130, It can be seen that the sizes are different. In other words, the stiffness and the loss coefficient measured for each of the plurality of dummies 130 arranged on the top of the sheet 101 may be different from each other.

The measurement unit 140 may analyze the stiffness distribution and the loss coefficient distribution measured for each sheet 101 having different characteristics to determine the distribution of the stiffness distribution and the loss coefficient distribution An index including the average value can be calculated.

Hereinafter, the indexes of stiffness distribution and loss coefficient distribution for each sheet 101 will be described with reference to FIGS. 4A and 4B.

1, 4A and 4B, the measuring unit 140 analyzes the stiffness distribution of each of the sheets 101, and calculates an average value of the stiffness distributions of the respective sheets 101 based on the analysis result (FIG. 4A). The measurement unit 140 may analyze the loss coefficient distribution for each sheet 101 and calculate an index including an average value of the loss coefficient distribution for each sheet 101 based on the analysis result .

Here, the index may further include a standard deviation of the stiffness distribution and the loss coefficient distribution, respectively. To this end, the measuring unit 140 may calculate the index further including the standard deviation based on the maximum value and the minimum value of the stiffness distribution and the loss coefficient distribution, respectively.

The measuring unit 140 may compare and analyze the characteristics of the sheets 101 based on the calculated index. Thus, by extracting and analyzing the index representing the characteristics of the sheet through the stiffness distribution and the loss coefficient distribution for each of the sheets 101, the individual elements of the sheet 101 (stiffness and loss Coefficient) on the vibration characteristics of the seat 101 can be grasped objectively.

The measuring unit 140 derives a regression equation relating to the dynamic characteristics of the sheet 101 using the calculated index and calculates a subjective evaluation result on the comfort of the seat 101 using the derived regression equation Can be predicted.

Hereinafter, prediction of the subjective evaluation result on the comfort of the seat using the derived regression equation will be described with reference to FIG.

Referring to FIGS. 1 and 5, the measuring unit 140 measures In order to predict the subjective evaluation result, data (red) using the average value of each of the stiffness distribution and the loss coefficient distribution of the sheet 101 as a variable and the average value of the stiffness distribution and the loss coefficient distribution of the sheet 101 The data (green) used as a variable up to the standard deviation of the loss coefficient was used.

As a result, when the average value of each of the stiffness distribution and the loss coefficient distribution is used in the regression equation derived for predicting the subjective evaluation result, the measuring unit 140 can estimate the subjective evaluation result for each of the sheets 101 there was. Furthermore, when the measurement unit 140 is used up to the standard deviation of the loss coefficient in addition to the average value of each of the stiffness distribution and the loss coefficient distribution, it is possible to more accurately predict the subjective evaluation result of the sheet 101.

Thereby, according to the embodiment of the present invention, the dynamic characteristics of the seat 101 are objectively measured and compared with the dynamic comfort evaluation (subjective evaluation) of the seat 101, Can be improved.

2 is a view for explaining an apparatus for measuring dynamic stiffness and loss coefficient distribution of a seat for evaluating dynamic comfort of a seat according to another embodiment of the present invention.

2, the dynamic stiffness and loss coefficient distribution device 200 for evaluating the dynamic comfort of a seat according to another embodiment of the present invention includes an acquisition unit 210, a comparison unit 220, (230).

The acquiring section 210 acquires an experimental measurement of complex stiffness for each of a plurality of dummies (see "130 " in FIG. 1) arranged on the top of the sheet (see" 101 "in FIG. 1).

To this end, the obtaining unit 210 obtains the power spectral density calculated based on the autocorrelation function of the second vibration signal in accordance with the vibration of each of the plurality of dummies, and the power spectral density calculated based on the reference spectral density The complex stiffness experimental measurements can be obtained using an experimental transfer function derived from the cross spectral density calculated based on the cross correlation function of the first and second vibration signals.

Wherein the autocorrelation function used to obtain the experimental measurements and the power spectral density calculated based on the autocorrelation function and the cross-spectral density calculated based on the cross-correlation function and the cross- Is similar to or the same as the method of calculating by the measuring unit in one embodiment, so that the explanation thereof will be omitted in another embodiment of the present invention.

The obtaining unit 210 may obtain a theoretical transfer function modeled theoretically for each of the plurality of dummies.

At this time, the acquiring unit 210 may acquire the theoretical transfer function by modeling the seat with a spring, and analyzing the seat and the plurality of dummies as a mass-spring system.

Here, the spring may be modeled as a position and a number corresponding to the plurality of dummies.

That is, the obtaining unit 210 calculates a theoretical transfer function TF (t) for each of the plurality of dummies, considering the plurality of dummy masses m _n and the angular frequency ω corresponding to the plurality of dummy vibrations, _n ).

The above theoretical transfer function can be derived by the following equation (6).

&Quot; (6) "

은 n번째 더미(모델)로부터 발생되는 진동 신호,

은 리지드 기판(모델)으로부터 발생되는 진동 신호,

은 n번째 더미(모델)를 지지하고 있는 시트부분의 복소강성, m_n은 n번째 더미(모델)의 질량, ω는 2Πf, f는 주파수를 나타낸다.here,

Is a vibration signal generated from the n-th dummy (model)

A vibration signal generated from a rigid substrate (model)

Is the complex stiffness of the seat portion supporting the nth dummy (model), m _n is the mass of the nth dummy (model), ω is 2πf, and f is the frequency.

은 하기 수학식 7에 의해 도출될 수 있다.At this time,

Can be derived by the following equation (7).

&Quot; (7) "

Here, k represents the stiffness of the sheet,? Represents the loss coefficient of the sheet, and i represents the imaginary number.

The comparator 220 compares the real and imaginary parts of each of the experimental measurements of the complex stiffness with the real and imaginary parts of the theoretical transfer function.

That is, the comparator 220 compares the real part of the experimental measurement with the real part of the theoretical transfer function for each of the plurality of dummies to derive a first relational expression having the stiffness as a variable, And the imaginary part of the theoretical transfer function can be compared to derive a second relational expression having the stiffness and loss coefficient as a variable.

The comparator 220 may derive a solution of each of the variables from the simultaneous equations based on the first and second relational expressions. That is, the comparator 220 first obtains a value of the stiffness corresponding to the variable of the first relational expression from the first relational expression, substitutes the value of the stiffness into the second relational expression, The value of the corresponding loss coefficient can be obtained.

The measurement unit 230 may measure the solution of each of the variables derived for each of the plurality of dummies as the stiffness and loss coefficient of the sheet.

The measurement unit 230 may measure the stiffness distribution and the loss coefficient distribution of the sheet by curve fitting the measured stiffness and loss coefficient at each of the plurality of dummies.

The stiffness distribution and the loss coefficient distribution measurement of the sheet by the curve fitting are similar to or the same as the measurement method in the embodiment of the present invention, and thus description thereof will be omitted in another embodiment of the present invention.

The measuring unit 230 analyzes the stiffness distribution and the loss coefficient distribution measured for each sheet having different characteristics to calculate an index including the average value of the stiffness distribution and the loss coefficient distribution for each sheet can do.

At this time, the measuring unit 230 may further calculate the standard deviation of each of the stiffness distribution and the loss coefficient distribution as the index, based on the minimum value and the maximum value of the stiffness distribution and the loss coefficient distribution, respectively.

That is, the measurement unit 230 may calculate an index including the mean value and the standard deviation of the stiffness distribution and the loss coefficient distribution for each sheet.

The measuring unit 230 may derive a regression equation for the dynamic characteristics of the sheet using the calculated index and predict the subjective evaluation result on the comfort of the sheet using the derived regression equation.

The measuring unit 230 may perform other functions, which are similar to or the same as the functions of the measuring unit 140 of FIG. 1, so that a description thereof will be omitted in another embodiment of the present invention .

6 is a flowchart illustrating a method of measuring dynamic stiffness and loss coefficient distribution of a seat for evaluating dynamic comfort of a seat according to an embodiment of the present invention.

Referring to FIGS. 2 and 6, in step 610, the dynamic stiffness and loss coefficient distribution measuring device 200 of the sheet measures the complex stiffness of each of a plurality of dummies 130 arranged on the top of the sheet, .

At this time, the dynamic stiffness and loss coefficient distribution measuring device 200 of the sheet may interpret the sheet and the plurality of dummies as a mass-spring system to obtain the theoretical transfer function.

Next, in step 620, the dynamic stiffness and loss coefficient distribution measuring device 200 of the seat calculates the real and imaginary parts of each of the complex stiffness experimental measurements, theoretically for each of the plurality of dummies 130 Compare the real and imaginary parts of a theoretical transfer function.

In other words, the dynamic stiffness and loss coefficient distribution measuring apparatus 200 of the present invention is characterized in that, for each of the plurality of dummies 130, a solution of the simultaneous equations based on a relational expression for comparing a real part and an imaginary part of the experimental measurement value and the theoretical transfer function, Can be derived.

Next, in step 630, the dynamic stiffness and loss coefficient distribution measuring apparatus 200 measures the stiffness and loss coefficient of the sheet based on the comparison result.

At this time, the dynamic stiffness and loss coefficient distribution measuring apparatus 200 can measure the stiffness distribution and loss coefficient distribution of the sheet by curve fitting the measured stiffness and loss coefficient of the sheet.

Accordingly, the dynamic stiffness and loss coefficient distribution measuring apparatus 200 can predict the subjective evaluation result on the comfort of the seat by utilizing the stiffness distribution and the loss coefficient distribution of the seat.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the scope of the appended claims and equivalents thereof.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, Modification is possible. Accordingly, the spirit of the present invention should be understood only in accordance with the following claims, and all equivalents or equivalent variations thereof are included in the scope of the present invention.

101: Sheet
110: Exciter
120: Rigid substrate
130: Pile
140: Measuring section (one embodiment)
142: first sensor
144: second sensor
210:
220:
230: Measurement section (another embodiment)

Claims (15)

An exciter for generating vibration;
A rigid substrate mounted on the vibrator and vibrated by driving the vibrator to apply an exciter to the sheet disposed on the upper portion;
A plurality of dummies arranged on the sheet and vibrating respectively by the vibrations of the rigid substrate; And
A first sensor installed on the rigid substrate and measuring a first vibration signal corresponding to the vibration of the rigid substrate, and a second sensor installed on each of the plurality of dummies to measure a second vibration signal according to the vibration transmitted to each of the plurality of dummies And a second sensor for measuring a stiffness and a loss coefficient of the sheet based on the first and second vibration signals,
And a dynamic stiffness and loss coefficient distribution measuring device for evaluating the dynamic stiffness and loss coefficient distribution of the seat for evaluating the dynamic comfort of the seat.
The method according to claim 1,
The measuring unit
Wherein the stiffness and loss coefficient of the seat are measured using a transfer function based on the first and second vibration signals.
3. The method of claim 2,
The measuring unit
A power spectral density calculated based on an autocorrelation function of the second vibration signal and a mutual spectral density calculated based on a cross correlation function of the first vibration signal and the second vibration signal as reference vibration signals, Deriving a transfer function and measuring the stiffness and loss coefficient of the seat using the derived transfer function, wherein the stiffness and loss coefficient of the seat are measured using the derived transfer function.
The method according to claim 1,
The measuring unit
Characterized in that the stiffness and loss coefficients measured at each of the plurality of dummies are subjected to curve fitting to measure the stiffness distribution and the loss coefficient distribution of the sheet. Distribution measuring device.
5. The method of claim 4,
The measuring unit
Wherein the stiffness distribution and the loss coefficient distribution measured for each sheet having different characteristics are analyzed to calculate an index including an average value of each of the stiffness distribution and the loss coefficient distribution for each sheet, Wherein the regression equation relating to the dynamic characteristics of the seat is derived and the subjective evaluation result on the comfort of the seat is predicted using the derived regression equation. Loss factor distribution measuring device.
6. The method of claim 5,
The index
Further comprising a standard deviation calculated based on the maximum value and the minimum value of each of the stiffness distribution and the loss coefficient distribution, and the dynamic stiffness and loss coefficient distribution measuring device for the seat for dynamic comfort evaluation of a seat.
The method according to claim 1,
The first and second sensors
Wherein the dynamic stiffness and loss coefficient distribution measuring device comprises an accelerometer sensor.
An acquiring unit for acquiring an experimental measurement of complex stiffness for each of a plurality of dummies arranged in an upper portion of the sheet;
A comparison unit comparing the real and imaginary parts of each of the complex stiffness experimental measurements with a real part and an imaginary part of a theoretical transfer function modeled theoretically for each of the plurality of dummies; And
Based on the result of the comparison, measures a stiffness and a loss coefficient of the sheet,
And a dynamic stiffness and loss coefficient distribution measuring device for evaluating the dynamic stiffness and loss coefficient distribution of the seat for evaluating the dynamic comfort of the seat.
9. The method of claim 8,
The obtaining unit
A power spectral density calculated based on an autocorrelation function of a second vibration signal in accordance with the vibration of each of the plurality of dummies, and a second vibration signal, which is a reference vibration signal applied to the seat through the vibrator, Characterized in that the experimental measurements of the complex stiffness are obtained using an experimental transfer function derived from the mutual spectral density calculated on the basis of the cross-correlation function, characterized in that the dynamic stiffness and loss coefficient distribution measurement Device.
9. The method of claim 8,
The obtaining unit
Characterized in that the sheet is modeled by a spring to obtain the theoretical transfer function by analyzing the sheet and the plurality of dummies into a mass-spring system. Dynamic stiffness and loss factor distribution measuring device.
9. The method of claim 8,
The comparing unit
Comparing a real part of the experimental measurement with a real part of the theoretical transfer function to derive a first relationship having the stiffness as a variable and comparing the imaginary part of the experimental measurement with the imaginary part of the theoretical transfer function for each of the plurality of dummies, Deriving a second relational expression having the stiffness and loss coefficients as variables, deriving a solution of each of the variables from the simultaneous equations based on the first and second relational expressions,
The measuring unit
Wherein the solution of each of the variables derived for each of the plurality of dummies is measured as the stiffness and the loss coefficient of the seat, and the dynamic stiffness and loss coefficient distribution measuring apparatus for the seat for dynamic comfort evaluation of the seat.
9. The method of claim 8,
The measuring unit
Wherein the stiffness distribution and the loss coefficient distribution of the seat are measured by curve fitting the measured stiffness and loss coefficient in each of the plurality of dummies, and measuring the dynamic stiffness and loss coefficient distribution of the seat for dynamic comfort evaluation of the seat. .
13. The method of claim 12,
The measuring unit
Analyzing the stiffness distribution and the loss coefficient distribution measured for each sheet having different characteristics to calculate an index including an average value of each of the stiffness distribution and the loss coefficient distribution for each sheet, Wherein the regression equation relating to the dynamic characteristics of the seat is derived using the calculated regression equation and the subjective evaluation result on the comfort of the seat is predicted using the derived regression equation, And a loss coefficient distribution measuring device.
14. The method of claim 13,
The index
Further comprising a standard deviation calculated based on the maximum value and the minimum value of each of the stiffness distribution and the loss coefficient distribution, and the dynamic stiffness and loss coefficient distribution measuring device for the seat for dynamic comfort evaluation of a seat.
In a dynamic stiffness and loss coefficient distribution measuring device, obtaining an experimental measurement of complex stiffness for each of a plurality of dummies arranged on top of a sheet;
Comparing the real and imaginary parts of each of the complex stiffness experimental measurements with a real part and an imaginary part of a theoretical transfer function modeled theoretically for each of the plurality of dummies; And
In the dynamic stiffness and loss coefficient distribution measuring apparatus, measuring the stiffness and loss coefficient of the sheet based on the comparison result
And measuring the dynamic stiffness and loss coefficient distribution of the seat for dynamic comfort evaluation of the seat.

Images