JP2001066181A - Minute gravity vibration measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To shorten a collating time by a computer, and improve precision. SOLUTION: Detection signals from vibration sensors 51a, 51b... are inputted into a computer 10 as digital data by A/D converters 52a, 52b.... Vibration patterns of each vibration generation source are retained as digital data in a data base 11, and the computer 10 compares and checks a measured value with specific vibration data at S(1), and if the vibration is specified at S(2), the result is displayed on a display/output device 55. If the vibration is not specified, checking with another vibration pattern is executed, and the checking is repeated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microgravity vibration measuring method, and detects a microvibration in a microgravity space such as the universe, and compares the characteristics of the vibration with known vibration characteristics to identify a vibration source. In this case, the collation time is shortened and the accuracy is improved.

[0002]

2. Description of the Related Art In recent years, various experiments and communication services have been carried out in outer space by a space station, a space shuttle, an artificial satellite, and the like. It is mentioned that microgravity (μ-G: 1 × 10 ⁻⁵ G or less) environment is ensured. Various vibrations occur in such microgravity, and the microgravity environment is easily destroyed.
For example, in a space station, a large vibration is caused by a collision of Meteoroid or Debris with the station. For such vibrations, it is necessary to detect the vibrations, analyze the vibrations to understand the source of the vibrations, and specify the location of the vibrations. For example, at the space station, the collision of meteoroids and debris, the collision position, vibration energy, frequency, amplitude, etc. are accurately detected,
Countermeasures must be taken against collisions. However, the technology for accurately grasping the vibration in the microgravity environment in outer space has not been established at present.

[0003] FIG. 7 is a typical block diagram of the related art for measuring and analyzing the vibration generated under the microgravity environment as described above. In the figure, reference numeral 50 denotes a computer, 51a, 51b,... Are a plurality of vibration sensors for detecting various vibrations, and 52a, 52b,. This is an A / D converter for converting into a digital signal. 53 is D
A plurality of vibration sensors 51a, 51b,... Are managed by an SP (Digital Signal Processor)
Connect to Reference numeral 54 denotes a database which holds data on vibration patterns at various vibration sources.
55 is a display / output device. In such a configuration, the database 54 has characteristic data for each vibration source, as will be described later, and the data is line data obtained by formulating the inclination of the vibration for each change in the vibration component. We hold as.

The vibrations detected by the vibration sensors 51a, 51b,... Are input to the computer 50 by the DSP 53, and the computer 50 first converts the change in the vibrations into mathematical data in step SS to obtain line data. Next, SS
In, the line data of various vibration patterns are fetched from the database 54, the data is referred to, the data is compared with the line data of the actually measured values, and when the vibration matches the data cited in the database 54, the source of the vibration, The characteristic is specified, displayed or output on the display / output device 55, and if not specified, the next comparison is performed.

[0005] The vibration sensor 51a, 5
The outputs detected by 1b,... Are input to the computer 50 and analyzed. In this way, it is possible to detect the vibration of the space station caused by a factor such as the collision of meteoroids and debris, and to specify the location.

FIG. 8 shows an example of line data of a vibration spectrum measured by the above-described vibration sensor. (A) shows the frequency on the horizontal axis and the gravity on the vertical axis, (X) shows the actual measurement value measured by the vibration sensor, and (Y) shows the pattern of the vibration data stored in the database 54. (Z) is a reference value, and is a value for monitoring vibration with reference to vibration exceeding this reference value. (B) is a diagram showing an example of formulating the measured value (X) in the pattern of (a). In the figure, (1), (2) to (12) are represented by mathematical expressions indicating the respective slopes corresponding to the changes of each vibration, and are actually measured by the mathematical expressions of (1), (2) to (12). The value (X) is grasped, managed by the computer 50 as line data, and provided for calculation. In addition,
If these changes are continuously grasped by one mathematical expression, they can be displayed by one mathematical expression.

[0007] By managing the vibration spectrum as line data as shown in FIG. 8, the actual measured value (X) inputted in the computer 50 is converted into a mathematical expression in SS and converted into line data as shown in FIG. 7. And
In the SS, the vibration is specified by comparing with the vibration pattern of the line data stored in the database 54.

[0008]

As described above, when measuring and analyzing micro vibration data in a conventional microgravity environment, a vibration spectrum is taken as line data and stored in advance as line data. Analysis and identification of vibrations are performed by comparing with vibration patterns of various vibration sources. The line data is used to formulate the inclination of the change of each vibration, and these formulas are compared and collated by a computer. Therefore, the collation by the computer program takes time and the precision of the collation decreases.

Also, the vibration pattern may change over time depending on the type of vibration, and the characteristics of the vibration change between the measurement time point and the subsequent vibration pattern, and do not change with time. In some cases, it is not possible to specify an accurate vibration only by comparing with data. Furthermore, when performing digital processing and analyzing and collating vibrations with a computer, there is a limit to the maximum value of the high frequency of the vibration sensor to be detected, especially at a frequency of 50,000 KHz or more, for example, debris in space. There has been a problem in detecting vibrations such as short pulse-like vibrations such as shock waves due to collisions.

Accordingly, the present invention provides a method of collating actual measured values of vibration measured by a vibration sensor with previously stored vibration data by using a computer. To improve the matching accuracy, and also to detect the vibration generated from the vibration source in a wide band from low frequency to high frequency, and to obtain the accurate scale and source of the vibration. It was made to provide a method.

[0011]

The present invention provides the following measuring methods (1) to (5) in order to solve the above-mentioned problems.

(1) Vibration generated in a structure in a microgravity space is measured as a vibration spectrum by a vibration sensor, input to a computer, and compared with a pattern of vibration spectra of various vibration generation sources stored in advance and collated. In the microgravity vibration measurement method for identifying the generated vibration, the measured vibration spectrum and the pattern of the vibration spectrum of the vibration source are taken as digital signal points in a frequency band, compared, and compared. Characteristic microgravity vibration measurement method.

(2) Vibration generated in a structure in a microgravity space is measured as a vibration spectrum by a vibration sensor, input to a computer, and compared with a pattern of a vibration spectrum of various vibration sources stored in advance and collated. In the microgravity vibration measuring method for specifying the generated vibration, the measured vibration spectrum and the vibration spectrum pattern of the vibration generation source can be taken as points or lines of a digital signal in a frequency band, and the vibration generation can be performed. A microgravity vibration measuring method, wherein the vibration spectrum of the source comprises a plurality of time-dependent vibration patterns at predetermined time intervals.

(3) The vibration sensor comprises a low-frequency sensor and a high-frequency sensor.
Or the microgravity vibration measuring method according to (2).

(4) The method of measuring microgravity vibration according to (2), wherein the time-dependent change vibration pattern comprises three patterns for one vibration source.

(5) The microgravity vibration measuring method according to claim 3, wherein the low-frequency sensor is a sensor using a piezoelectric element, and the high-frequency sensor comprises a microphone.

In the measurement method (1) of the present invention, the actual measured value of the vibration from the vibration sensor is grasped by inputting the change of the vibration as a digital value for each frequency to the computer.
In addition, the computer stores in advance a pattern of a known vibration spectrum of each vibration source, and the computer compares the measured value with the vibration pattern of each vibration source as a digital value at each frequency as point data, and performs collation. Then, the vibration of the actually measured value is specified from the similar vibration pattern. In the conventional computer collation, a change in vibration is expressed as a mathematical expression, and the inclination of the vibration is compared and collated as line data. Therefore, the matching takes time and accuracy is reduced. Collation time can be greatly reduced.

In (2) of the present invention, in the same manner as in the above (1), the actual measured value is compared with the vibration pattern using digital data, and the vibration pattern of each vibration source is a plurality of time-dependent vibration patterns. Because of this, in addition to shortening the collation time, collation is performed in consideration of changes over time, so that collation accuracy is significantly improved.

In (3) of the present invention, since the vibration sensor includes a low-frequency sensor and a high-frequency sensor, it is possible to accurately grasp a wide-band vibration generated from a vibration source. In particular, since the vibration of a short shock wave at the time of collision such as debris colliding with the spacecraft is accurately detected by the high-frequency sensor, the position, scale, and the like of the vibration source can be grasped.
Further, in (5) of the present invention, the low-frequency sensor comprises a sensor using a piezoelectric element, and the high-frequency sensor comprises a microphone, thereby facilitating the configuration of the vibration sensor. Since the vibration pattern of the change with time in the invention of (3) is limited to three patterns, it is possible to provide a practical measurement method that substantially improves the matching accuracy in consideration of the matching time and the like.

[0020]

Embodiments of the present invention will be specifically described below with reference to the drawings. FIG. 1 is a system configuration diagram to which the microgravity vibration measuring methods according to the first and second embodiments of the present invention are applied. In the figure, reference numerals 51 to 53 and 55 are the same as those of the conventional example shown in FIG. 7 and will be described with reference to the same reference numerals. However, the features of the present invention are a vibration data collation method implemented by the computer 10 and a database. The pattern of the vibration data in FIG. 11 is described in detail below.

In FIG. 1, vibration sensors 51a, 51
b, are converted into digital data by A / D converters 52a, 52b, respectively.
The signal of the sensor to be measured and collated is selected by the DSP 53 and input to the computer 10. Computer 1
If the value is 0, in step S, the data of the vibration patterns of the various vibration sources stored in the database 11 is referred to, and is compared with the measured value.

The database 11 holds in advance digital data of known vibration spectra such as vibration patterns at various places at the time of collision of each device and generation source, for example, a pump, a motor, and a meteoroid / debris in space. , And these data are compared with actual measurement values and collated. The actual measured values of the vibration data and the vibration pattern data handle the characteristics of the change at each predetermined frequency as digital data. S
In, the actually measured value and various vibration patterns are compared and collated with digital data, and if a vibration is specified, it is displayed or output to the display / output device 55 in S.

FIG. 2 shows the digital data described above. In FIG. 2A, the horizontal axis represents frequency and the vertical axis represents gravity.
(X) is digital data of actually measured values, and a circle is digital data of vibration at each frequency. (Z) is a reference value, which is represented by digital data indicated by triangles. (A)
Is a vibration pattern of a specific vibration source stored in the database 11, and is indicated by a hanging mark. The digital data at each of the frequencies (X) and (A) are compared and collated by the computer 10, and the closest vibration data pattern is selected to specify the vibration.

(B) is an actual measured value (X) of the above (a).
The actual measured values are (X1), (X
2), stored as digital data of (X13), and grasps the characteristics of vibration. (C) is a database 11
(A), (A1), (A2),... (A1)
The characteristic of vibration is grasped by the digital data of 3),
The digital data (X) and (A) are superimposed as shown in FIG.

FIG. 3 is an example of a flowchart of comparison and collation performed by the computer in the microgravity vibration measuring method according to the first embodiment of the present invention.
FIG. In the figure, after the start, first, S1
In step S2, actual measured data from the vibration sensor 51 is fetched as digital data, and in step S2, the first vibration pattern P (N) is fetched from the database 11 and set.
This is selected in S3. In the database 11, each vibration pattern is stored as a digital value for each of the vibration patterns P (1), P (2), to P (N), and in S4, the measured value and each digital value of the vibration pattern P (N) are stored. The data is compared and collated, the correlation between them is obtained, the correlation F (N) as a whole with the set vibration pattern P (N) is calculated and stored in the memory. In S5, if the result of the collation in S4 shows that the collation between each data of the actually measured value and the vibration pattern substantially coincides, the process proceeds to S8. In S5,
If the vibration has not been identified yet, step S6 is followed by the next pattern. If all P (N) have not been executed in step S7, the process returns to step S3, and the same comparison is repeated again.

In S7, the collation with all the P (N) is completed, and when almost coincident with the vibration pattern in S5, the correlation F () with each vibration pattern calculated and obtained in S8 is obtained. N) is checked, and the vibration pattern closest to these results is specified, and the vibration source actually measured from the vibration pattern specified in S5, its position, and the like are specified, and the processing is terminated.

According to the microgravity vibration measuring method of the first embodiment described above, the vibration spectrum data is grasped as digital data, and the vibration patterns of various vibration sources stored in the database 11 in advance by the computer 10 are obtained. Compared with the conventional digital data, the collation time is greatly reduced as compared with the conventional method in which vibration data is grasped as line data, compared and collated.

FIG. 4 is a diagram showing vibration data of the microgravity vibration measuring method according to the second embodiment of the present invention. In the second embodiment, the vibration spectrum data is taken as vibration characteristic data that changes over time, and each vibration pattern is held as a plurality of vibration patterns associated with the time change. It is designed to compare and collate with changes in nature.

In FIG. 4A, the figure is a reference value,
(X) are measured values, which are represented by the same digital values as in the example shown in FIG. (A) T ₁ is a pattern based on a digital value at time T ₁ among specific vibration patterns held in the database 11, and (A) T ₂ is time T ₂
, And (A) T ₃ is the pattern at time T ₃ . In FIG. 1, the computer 10 superimposes the vibration patterns of these data (A) T ₁ , (A) T ₂ , and (A) T ₃ , and compares and collates these data with the actually measured value (X) with each digital data. Then, the vibration is specified.

(B) shows only the vibration pattern of (A) T ₁ among the digital data of (a) and the measured value (X), and (c) shows only (A) T ₂ ,
(D) is an illustration with (A) T ₃ respectively only measured values (X). Vibration pattern (A) as shown
Since the vibration pattern changes at times T ₁ , T ₂ , and T ₃ , and accurate collation cannot be performed using only one pattern that does not change with time, in the second embodiment of the present invention, the actual measurement is performed. The value (X) and (A) T ₁ , (A) T ₂ , (A)
Comparing the vibration pattern with the time course of T _3, collated,
It is possible to obtain a comprehensive correlation and perform accurate collation.

FIG. 5 is a flowchart of the comparison and collation performed by the computer in the microgravity vibration measuring method according to the second embodiment of the present invention, and is a detailed diagram of S and S shown in FIG. In the figure, after starting, first, in S1, measurement data from the vibration sensor 51 is fetched as digital data, and in S2, the first vibration pattern P
(N) is selected, and the setting is taken in from the database 11 in S3. The database 11 holds digital data of P (1), P (2), .about.P (N) for each vibration source, and each digital data is changed over time T ₁ ,
It is composed of digital data of a vibration pattern for each of T ₂ , T _{3 to} T _X.

In S4, the measured value and the vibration pattern P
The digital data of each pattern at times T ₁ , T ₂ , T _{3 to} T _X of (N) is compared and collated, and a total correlation F (N) between the actually measured value and P (N) is obtained. Is stored in the memory. Next, if the vibration cannot be specified in S5, the next pattern is further performed in S6, and if all P (N) have not been performed in S7, the process returns to S3, and the same collation is repeated.

In S7, all the comparisons with P (N) have been completed, and when almost coincident with the vibration pattern in S5, the correlation F () with each vibration pattern calculated and calculated in S8 is obtained. N), the closest vibration pattern is specified from these results, and the vibration source actually measured from the vibration pattern specified in S5, its position,
Etc., and terminate.

According to the microgravity vibration measuring method of the second embodiment described above, the vibration spectrum data is grasped as digital data, and at the same time, T ₁ , T ₂ , T ₃ , and T ₃ are obtained as various vibration patterns. vibration data through T _X as held in the database 11, the computer 1
Compared and compared the actual measurement value and these temporal vibration data comprehensively at 0, the collation accuracy is remarkably improved compared to the conventional method of drawing, comparing and comparing the vibration data as line data. Is what you do. The pattern of the vibration data of the change with time depends on the vibration characteristics in consideration of the matching time, but about three types such as T ₁ , T ₂ and T ₃ are appropriate.

FIG. 6 is a configuration diagram of a microgravity vibration measuring method according to a third embodiment of the present invention. In the figure, a low-frequency vibration sensor 20 and a high-frequency acoustic sensor 30 are used as vibration sensors. In the figure, 20a,
20b,-are low frequency vibration sensors, 30a, 30b,-
Is a high frequency acoustic sensor, and the low frequency vibration sensor 20
a, 20b,... are A / D converters 21a, 21b,
Are converted into digital data by the, and the signals from the high frequency acoustic sensors 30a, 30b,
a, 31b,.
The data is input to the SP 53, and the computer 10
Is input to

Examples of the low-frequency vibration sensor, such as a piezoelectric element is used to detect the vibration of a frequency of up to 50,000 H _Z,
For higher frequency vibrations, a high frequency acoustic sensor 30 such as a microphone is used. The results detected by these two sensors are input to the computer 10 from the DSP 53, supplied and managed, and compared with a vibration pattern stored in advance, and processed by the method according to the first or second embodiment. be able to.

According to the microgravity vibration measuring method according to the third embodiment described above, the wide-band vibration generated from the vibration source is used for the low-frequency vibration, and the low-frequency vibration is used for the low-frequency vibration sensors 20a and 20a.
b, ..., the high frequency vibration is generated by the high frequency acoustic sensor 30a,
Since the vibration is detected and detected in each of 30b, ..., it is possible to more accurately measure the magnitude of the vibration, the location of the vibration source, and the like, and in particular, a short pulse due to the collision of debris colliding with a space station or the like. Shape vibrations and the like can be effectively grasped.

The microgravity vibration measuring method according to the first to third embodiments described above is applied to a space station,
However, the present invention is not limited to use in outer space, but can be applied to the analysis of minute vibrations in ground plants such as semiconductor manufacturing factories and the like, and similar effects can be obtained. It is something that can be done.

[0039]

The method for measuring microgravity vibration according to the present invention comprises:
(1) Vibration generated in a structure in a microgravity space is measured as a vibration spectrum by a vibration sensor, input to a computer, and compared with a pattern of a vibration spectrum of various vibration sources stored in advance, collated and generated. In the microgravity vibration measuring method for specifying vibration, the measured vibration spectrum and the pattern of the vibration spectrum of the vibration source are taken as digital signal points in a frequency band, compared, and collated. . In the conventional computer collation, the change in vibration is expressed as a mathematical expression, and the inclination of the vibration is compared and collated as line data. Therefore, the matching takes time and the accuracy is reduced.
Then, the collation time can be significantly reduced by the above method.

According to the method (2) of the present invention, in the microgravity vibration measuring method similar to the invention (1), the pattern of the measured vibration spectrum and the pattern of the vibration spectrum of the vibration source are in a frequency band. It is characterized in that it can be taken as a point or a line of a digital signal, and the vibration spectrum of each vibration source is composed of a plurality of time-varying vibration patterns at predetermined time intervals. According to such a method, in addition to the shortening of the collation time, the collation is performed in consideration of the change over time, so that the collation accuracy is significantly improved.

In (3) of the present invention, since the vibration sensor is composed of a low-frequency sensor and a high-frequency sensor, it is possible to accurately grasp a wide-band vibration generated from a vibration source. In particular, since the vibration of a short shock wave at the time of collision such as debris colliding with the spacecraft is accurately detected by the high-frequency sensor, the position, scale, and the like of the vibration source can be grasped.
Further, in (5) of the present invention, the low-frequency sensor comprises a sensor using a piezoelectric element, and the high-frequency sensor comprises a microphone, thereby facilitating the configuration of the vibration sensor. Since the vibration pattern of the change with time in the invention of (3) is limited to three patterns, it is possible to provide a practical measurement method that substantially improves the matching accuracy in consideration of the matching time and the like.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a system that implements a microgravity vibration measurement method according to a first embodiment of the present invention.

2A and 2B show vibration data applied to the measurement method according to the first embodiment of the present invention, wherein FIG. 2A shows actual measured values, reference values, and vibration patterns, FIG. 2B shows actual measured values, and FIG. The digital data of the vibration pattern is shown.

FIG. 3 is a flowchart of a process by a computer of the measurement method according to the first embodiment of the present invention.

Figure 4 shows the vibration data microgravity vibration measurement method according to a second embodiment of the present invention, (a) is a measured value reference value, the temporal vibration pattern, in (b) the time T ₁ vibration pattern and the measured values, indicating (c) vibration pattern and the measured value at time T _2, the actual measurement value and the vibration pattern in (d) are time T _3, respectively.

FIG. 5 is a flowchart of a process by a computer of a measurement method according to a second embodiment of the present invention.

FIG. 6 is a configuration diagram of a system that implements a microgravity vibration measurement method according to a third embodiment of the present invention.

FIG. 7 is a configuration diagram of a system that implements a conventional microgravity vibration measurement method.

8A and 8B show conventional forms of vibration data. FIG. 8A shows line data of actually measured values and vibration patterns, and FIG. 8B shows line data of actually measured values.

[Explanation of symbols]

 10 Computer 11 Database 20a, 20b, ~ Low frequency vibration sensor 21a, 21b, ~ A / D converter 30a, 30b, ~ High frequency acoustic sensor 31a, 31b, ~ Sound filter 51a, 51b, ~ Vibration sensor 52a, 52b, to A / D converter 53 DPS 55 display / output device

Claims (5)

[Claims] 1. A vibration generated in a structure in a microgravity space is measured as a vibration spectrum by a vibration sensor, input to a computer, and compared with a pattern of vibration spectra of various vibration sources, which are stored in advance, and collated. In the microgravity vibration measuring method for specifying the generated vibration, the measured vibration spectrum and the vibration spectrum pattern of the vibration source are taken as digital signal points in a frequency band, compared, and compared. Microgravity vibration measurement method. 2. A vibration generated in a structure in a microgravity space is measured as a vibration spectrum by a vibration sensor, input to a computer, and compared with a pattern of vibration spectra of various vibration sources held in advance and collated. In the microgravity vibration measuring method for specifying the generated vibration, the measured vibration spectrum and the pattern of the vibration spectrum of the vibration source can be taken as points or lines of a digital signal in a frequency band, and each of the vibration sources Wherein the vibration spectrum comprises a plurality of temporally changing vibration patterns at predetermined time intervals. 3. The microgravity vibration measuring method according to claim 1, wherein the vibration sensor comprises a low-frequency sensor and a high-frequency sensor. 4. The microgravity vibration measuring method according to claim 2, wherein said temporally changing vibration pattern comprises three patterns for one vibration source. 5. The microgravity vibration measuring method according to claim 3, wherein the low-frequency sensor is a sensor using a piezoelectric element, and the high-frequency sensor comprises a microphone.