JP2002041143A - Method for diagnosing abnormality of operating part and method for diagnosing abnormality of compressor valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for diagnosing the abnormality of an operating part capable of individually diagnosing the abnormality of a plurality of operating parts on the basis of an acoustic signal. SOLUTION: An acoustic signal obtained by a microphone 10 is recorded in a data recorder 20. The acoustic signal is filter-processed by a filter device 21 so that at least one filter processing signal in which at least one kind of acoustic waveform corresponding to the frequency components of a sound outputted from at least one operating part of a plurality of operating parts clearly appears can be obtained. A data analyzer 22 judges the generation of any abnormality in each operating part on the basis of the acoustic waveform.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention converts sound generated from a device having a plurality of operating parts such as a valve into an acoustic signal with a microphone, and diagnoses an abnormality of the plurality of operating parts such as a valve based on the acoustic signal. How to do it.

[0002]

2. Description of the Related Art In a conventional method for diagnosing abnormalities of a plurality of operating units based on an acoustic signal, a waveform of a spectrum on a frequency axis of the acoustic signal is observed, and based on a change in the spectrum waveform, the operating unit is diagnosed. An abnormality was diagnosed.

[0003]

However, according to the conventional diagnostic method, it is known that an abnormality has occurred in any of the plurality of operation units, but an abnormality has occurred in any one of the plurality of operation units. I didn't know. Therefore, it was not possible to make an individual diagnosis of each operating unit. It has been considered that a vibration sensor is installed near each operating unit to detect an abnormality of each operating unit. However, in the method using the vibration sensor, the vibration sensor has to be individually installed in a plurality of operation units, and therefore, there are cases where it is disadvantageous to use this method for comprehensive monitoring and maintenance.

An object of the present invention is to provide a method for diagnosing an abnormality in an operation unit which can individually diagnose an abnormality in a plurality of operation units based on an acoustic signal.

It is another object of the present invention to provide a method of diagnosing a valve abnormality of a compressor, which can individually diagnose abnormality of a plurality of valves based on an acoustic signal.

It is another object of the present invention to provide a method for diagnosing an abnormality in an operating unit which can individually and more accurately diagnose an abnormality in a plurality of operating units based on an acoustic signal.

[0007]

According to the present invention, there is provided a method of converting sound generated from a device having a plurality of operating units into an acoustic signal by a microphone and diagnosing abnormalities of the plurality of operating units based on the acoustic signal. Target for improvement. Such a device is, for example, a compressor, and a part of the operating part of the compressor that needs to be replaced periodically is a valve. Therefore, the present invention is applied to such a valve abnormality diagnosis. Although any microphone may be used, it is preferable to remove disturbance as much as possible at the sound collecting stage.
For this purpose, for example, it is preferable to use a directional parabolic microphone in which a microphone is arranged at the center of a trumpet-shaped sound collector, or another directional microphone.

In the present invention, basically, an acoustic signal is filtered, and one or more types of acoustic waveforms corresponding to the frequency component of the sound emitted from at least one operating unit clearly appear on the time axis. The above-described filter processing signal is generated.

If one acoustic signal contains frequency components of a sound emitted from one operating unit, the same number of acoustic signals as the number of operating units are processed. When all the frequency components of the sounds output from the plurality of operation units are included in the acoustic signal, a filtered signal obtained by filtering only one acoustic signal is used. The filter processing used in the present invention is to make one or more types of acoustic waveforms corresponding to frequency components of sound emitted from at least one operation unit included in the acoustic signal appear. Therefore, the bandwidth of the filter to be used differs depending on the operation unit to be diagnosed. For example, in the case of a compressor, even if the type of valve used is the same, the sound generated from the valve part (operating part) according to the mounting state of the valve, the state of the valve plate, and the surrounding temperature condition Will be different. Therefore, in order to improve the sound waveform corresponding to the frequency component of the sound generated from each operation unit by the filter processing, it is ideally preferable to specify the band of the filter used for the filter processing for each operation unit. When one acoustic signal contains frequency components of sounds emitted from two or more operating units, a filter band that can retain some of two or more acoustic waveforms corresponding to those frequency components to a certain extent is specified. Is preferred.

[0010] A microphone is placed at a position close to an operation unit to be diagnosed, and a microphone is directed to the operation unit to obtain an acoustic signal.
If there is only an acoustic waveform corresponding to the frequency component of the sound generated by one of the operating units, specify the sound signal and the measurement location in association with each other, and determine the state of the corresponding operating unit from the acoustic waveform. Can. However, since the sound signal measured at a certain distance from the device includes sounds from multiple operating units, it is possible to specify which sound waveform corresponds to sound from which operating unit. difficult. Therefore, in order to facilitate such specification, the timing on the time axis of the sound generated from each of the plurality of operation units is specified in advance. Then, based on this timing, an acoustic waveform corresponding to a frequency component of a sound generated from an operating unit to be diagnosed is specified from one or more filter processing signals. The timing can be specified by various methods. For example, if a plurality of vibration detection sensors that detect vibrations generated from a plurality of operation units only once at the beginning are provided corresponding to the plurality of operation units, the timing may be determined based on the outputs of the plurality of vibration detection sensors. Can be. From the outputs of the plurality of vibration detection sensors, the operation timings of the plurality of operation units on the time axis can be known. If the operation order of the operation units is known, in this case, it is not necessary to provide the vibration sensors in all the operation units, and even by providing the vibration sensor in one operation unit, the operation timing of the other operation units can be known. . Alternatively, a rotation detector such as an encoder may be provided on the shaft, and the timing may be determined based on an output from the rotation detector.

The operation timing coincides with the timing on the time axis of the sound generated from each of the plurality of operation units.
Therefore, in this way, it is possible to know the timing on the time axis of the sound generated from each of the operation units to be diagnosed. According to the present invention, it is diagnosed based on the acoustic waveform specified in this manner whether or not an abnormality has occurred in the operation unit to be diagnosed. Thus, the states of the plurality of operating units can be individually known based on the acoustic signals, and it is possible to easily diagnose whether or not an abnormality has occurred in each of the operating units.

For example, it is conceivable to diagnose an abnormality using a reference acoustic waveform and an acoustic waveform. In that case,
First, an acoustic waveform obtained in a normal state of each of the plurality of operation units is recorded in advance as a reference acoustic waveform. Then, by comparing the reference acoustic waveform with the acoustic waveform included in the filter processing signal, it may be determined whether or not an abnormality has occurred in the operation unit to be diagnosed.

Various other diagnostic methods based on acoustic waveforms are conceivable. For example, changes in the amplitude of the acoustic waveform,
Change in the average value of the amplitude, change in the peak value of the amplitude, change in the frequency bandwidth of the filter required for extraction, change in the cutoff frequency of the filter required for extraction, attenuation tendency of the acoustic waveform, Based on at least one of the change and the correlation function between the reference acoustic waveform and the acoustic waveform, it is possible to diagnose whether or not an abnormality has occurred in the operation unit to be diagnosed.

When the abnormality of a plurality of valves of a compressor having a plurality of valves which open and close at predetermined time intervals is diagnosed by using the method of the present invention, conventionally, even if no abnormality occurs, the valves are periodically replaced. Since only the valve in which the abnormality has occurred can be replaced without performing the maintenance work that has been performed, the cost for maintenance can be significantly reduced.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1A is a conceptual diagram of a configuration of a reciprocating compressor for diagnosing an abnormality of an operating unit according to the present invention, and FIG. 1B is a diagram illustrating four valves or four valves arranged for one cylinder. It is the schematic which shows the positional relationship of a valve (two suction valves and two discharge valves). As shown in FIG. 1 (A), this compressor uses one motor 1 as a drive source and
The cylinders 2 to 5 are configured to operate.
Each of the cylinders 2 to 5 has two suction valves 6 and 7
And two discharge valves 8 and 9 are arranged. Inside each cylinder, the piston reciprocates between the crank side and the head side at a cycle of usually 5 to 10 Hz, and the four valves 6 to 9 open and close in order according to the reciprocation of the piston. The sucked fluid is compressed and discharged. Since the structure of the reciprocating compressor is publicly known, detailed description is omitted.

FIG. 2 is a diagram schematically showing the configuration of an apparatus used to carry out an embodiment of the method of the present invention. According to the present invention, in order to detect abnormalities of valves (suction valves 6 and 7 and discharge valves 8 and 9) of the compressor (equipment) shown in FIG. 10 is used. As the microphone 10, a directional parabolic microphone having a microphone arranged at the center of a trumpet-shaped sound collector is used so that disturbance can be removed as much as possible at the sound collecting stage. The microphone 10 may be fixed, but a portable microphone is used to reduce the cost.
1A and 1B, black circles P1 to P11 show examples of the arrangement positions of the microphones 10 when sound is collected by the portable microphones 10. FIG. Note that the microphone 10 is arranged in a non-contact state with the device.

In this example, in order to measure the timing, for example, four valves (a suction valve 6) of one cylinder 2 are used.
And 7 and the discharge valves 8 and 9) are provided with vibration detection sensors 12 to 15 including acceleration sensors and the like. The vibration detection sensors 12 to 15 are arranged in contact with the outer surface of the device at the positions indicated by the square marks in FIG. In this example, the output of the vibration detection sensors 12 to 15 is used to know the operation timing of the four valves of one cylinder 2, that is, the suction valves 6 and 7 and the discharge valves 8 and 9 (a plurality of operation units) on the time axis. Used for Vibration detection sensors 12-15
Is recorded in a data recorder (DAT recorder) 20 for recording data via the amplifiers 16 to 19. The data recorder 20 includes the microphone 10 described above.
The acoustic signal converted by the above is also recorded. The data recorder 20 is also portable, like the microphone 10, and is carried by an operator at the measurement site. The data recorder 20 may record data in either analog or digital form. But in this example,
Since a computer is used for data processing, all data is converted into a digital signal using an A / D converter built in the data recorder 20 and recorded in a digital format.

In the example of FIG. 2, the data recorder 20 and the filter device 21 are connected by wiring, but this state indicates the connection when the data analyzer 22 performs analysis after data collection. The filter device 21 first filters the acoustic signal recorded on the data recorder 20 to correspond to the frequency component of the sound emitted from at least one of the four valves (the plurality of operating units) on the time axis. To make the acoustic waveform visible.

FIG. 3 shows that a microphone 10 is installed at a position P1 in FIG. 1A, and an acoustic signal obtained by simultaneously collecting sounds generated from the four valves 6 to 9 is subjected to Fourier transform to obtain a power spectrum (frequency spectrum) on the frequency axis. FIG. 3 is an example of a diagram shown as a (sound pressure spectrum). The vertical axis in this figure is the sound pressure. According to the present invention, the frequency band components corresponding to the bands indicated by (1) to (3) in FIG. 3 are revealed as an acoustic waveform on the time axis by filtering.

When one sound signal contains only the frequency component of the sound emitted from one valve, it is necessary to measure the same number of sound signals as the number of four valves. However, all the frequency components of the sound from the four valves are included.
In the case of one acoustic signal, only one acoustic signal needs to be filtered.

The bandwidth of the filter used in the filter device 21 differs depending on the valve to be diagnosed. FIG. 4A is an example of a time waveform in which an acoustic signal before filter processing is represented on a time axis. FIG. 4B shows an example of a filtered signal in which one type of acoustic waveform AW corresponding to the frequency component of the sound emitted from one valve on the time axis has clearly appeared due to the filtering. And FIG. 4 (C)
Of the outputs of the vibration detection sensors 12 to 15 in FIG.
6B shows a time waveform of one output of a vibration detection sensor provided corresponding to a valve serving as a generation source of the acoustic waveform AW shown in FIG. Since the operation timing of the valve can be known from the vibration signal, it is possible to easily specify the valve that is the source of the acoustic waveform AW shown in FIG.

For example, in the case of a compressor, even if the type of valve used, that is, the valve, is the same,
The sound generated from the valve portion (operating portion) differs depending on the state of the valve plate, the surrounding temperature, the foreign matter being caught, and the like. Therefore, in order to improve the sound waveform corresponding to the frequency component of the sound generated from each valve by the filter processing, it is ideally preferable to specify the band of the filter used for the filter processing for each valve. When one frequency band component includes frequency components of sound emitted from two or more valves, 2 corresponding to those frequency components
It is necessary to specify a filter band that allows some or more types of acoustic waveforms to be present to some extent.

The selection of a filter band in the filtering process will be described with reference to FIGS. FIG.
(1) to (3) respectively show band characteristics of filters having three different bands. FIG. 5 (4) and (5)
Are 1 obtained from the vibration detection sensors 12 to 15 in FIG.
These are a suction valve vibration signal that detects vibration of one suction valve and a discharge valve vibration signal that detects vibration of one discharge valve. FIG. 5 (6) shows a time waveform of the acoustic signal before the filtering process. This acoustic signal contains frequency components of sound emitted from the two valves, the suction valve and the discharge valve. FIG. 5 (7) shows a filtered signal after filtering the acoustic signal of FIG. 5 (6) using a filter having the characteristics of FIG. 5 (1). In the state of FIG. 5 (7), two types of acoustic waveforms cannot be kept alive because the band of the used filter is inappropriate. FIG. 5 (8) shows a filtered signal after performing a filtering process on the acoustic signal of FIG. 5 (6) using a filter having the characteristics of FIG. 5 (2). FIG.
In the state of (8), since the band of the used filter is appropriate, the acoustic waveform AW1 corresponding to the frequency component of the sound emitted from the suction valve has been improved. FIG. 5 (9) shows a filtered signal obtained by performing a filtering process on the acoustic signal of FIG. 5 (6) using a filter having the characteristics of FIG. 5 (3). In the state of FIG. 5 (9), since the band of the used filter is appropriate, the sound waveform AW2 corresponding to the frequency component of the sound emitted from the discharge valve has been made healthy. By appropriately selecting the band of the filter used in the filter processing according to the valve in this manner, the sound waveform corresponding to the frequency component of the sound generated from the valve can be easily maintained.

A case in which four acoustic waveforms corresponding to the frequency components of the sounds generated from four valves from one acoustic signal using the present invention will be described with reference to FIG. FIGS. 6A to 6D show vibration signals obtained from the vicinity of the four valves 6 to 9 obtained from the vibration detection sensors 12 to 15 in FIG. 2, respectively. The operation timing of each valve can be known from these vibration signals. FIG. 6 (5) is obtained by selecting an optimum filter band for one acoustic signal including frequency components of sounds from four valves obtained from one acoustic signal and performing filter processing. This is a filtered signal.
In this filtered signal, acoustic waveforms AW1 to AW4 corresponding to the frequency components of the sounds generated from the four valves are alive. As can be seen from the operation timings of FIGS. 6 (1) to (4), the acoustic waveform AW1 indicates the operation state of the suction valve 1, and the acoustic waveform AW2 corresponds to FIGS. 6 (1) to (4).
As can be seen from the operation timing of FIG. 6, the operation state of the discharge valve 2 is shown, and the acoustic waveform AW3 is shown in FIGS.
As can be seen from the operation timing of (4), the operation state of the suction valve 2 is shown, and the acoustic waveform AW4 is shown in FIG.
To (4), the discharge valve 1
3 shows the operation state.

It should be noted that the microphone 10 may be arranged at each of the positions P10 to P13 in FIG. 1 (B) to obtain four acoustic signals corresponding to each valve, and to perform a filtering process on each acoustic signal. Since the valve can be specified from the type of the acoustic signal, an acoustic waveform necessary for diagnosis can be obtained without knowing the operation timing. For example, FIG.
When a microphone is installed at the position P1 shown in (A), the acoustic signal measured at that position includes frequency components of sounds generated from the plurality of valves.

In the present embodiment, the data analyzer 2
According to 2, based on the acoustic waveform extracted in this way, it is diagnosed whether an abnormality has occurred in the valve (operating unit) to be diagnosed. Thereby, the states of the plurality of valves can be individually known based on the acoustic signals, and it can be easily diagnosed whether or not each valve has an abnormality. The speaker 23 is used for confirming the operation timing by sound.

There are various methods of diagnosis based on the acoustic waveform. For example, as shown in FIG. 6 (5), abnormality diagnosis can be performed based on changes in the time intervals T1 to T4 between the acoustic waveforms. Changes in the amplitude of the acoustic waveform, changes in the average value of the amplitude, changes in the peak value of the amplitude, changes in the frequency bandwidth of the filter required for extraction, changes in the cutoff frequency of the filter required for extraction, and attenuation tendencies of the acoustic waveform Based on at least one of the correlation function (diagnosis element) between the reference acoustic waveform and the acoustic waveform, it is possible to diagnose whether or not an abnormality has occurred in the operation unit to be diagnosed. In the case of performing these diagnoses, as shown in FIG. 7, the above diagnostic element (vertical axis) is between the upper limit determination threshold and the lower limit determination threshold with respect to the acoustic signal measurement date (horizontal axis). , It is determined to be normal, and if it falls outside the threshold area, it can be determined that an abnormality has occurred.

A description will be given of a case in which abnormality of a valve (operating section) is diagnosed based on a reference acoustic waveform, that is, a correlation function between the reference acoustic waveform and the acoustic waveform among the above diagnostic elements. When the reference acoustic waveform and the acoustic waveform are used, first, an acoustic waveform obtained in a state where each of the valves (operating units) to be diagnosed is in a normal state is recorded as a reference acoustic waveform (FIG. 8 ( A) and (B)). Then, by comparing the reference acoustic waveform with the acoustic waveform included in the filter processing signal, it is diagnosed whether or not an abnormality has occurred in the operation unit to be diagnosed. Specifically, a correlation function (acoustic waveform / reference acoustic waveform) between the reference acoustic waveform in FIG. 8A and the acoustic waveform in the filtered signal in FIG. 8C is obtained, and a diagnosis target is obtained from the correlation function. Diagnosis is made as to whether or not an abnormality has occurred in the operation unit. For example, when the amplitude of the correlation function exceeds the upper and lower reference thresholds, it is determined to be abnormal, and the abnormality is determined by a change in the cycle of the correlation function.

In the above embodiment, the present invention is used for diagnosing an abnormality of a valve of a reciprocating compressor. However, the method of the present invention diagnoses an abnormality of an operation section of another apparatus having a plurality of operation sections. The present invention can naturally be applied to such a case, and the present invention is not limited to the embodiment.

[0030]

According to the present invention, it is possible to individually determine the states of a plurality of operating units to diagnose whether an abnormality has occurred in the operating unit to be diagnosed based on the acoustic waveform. Thus, there is an advantage that it is possible to easily diagnose whether or not an abnormality has occurred in each operation unit.

[Brief description of the drawings]

FIG. 1A is a conceptual diagram of a configuration of a reciprocating compressor for diagnosing an abnormality of an operation unit according to the present invention, and FIG.
FIG. 4 is a schematic diagram showing a positional relationship between four valves or valves (two intake valves and two discharge valves) arranged for one cylinder.

FIG. 2 is a diagram schematically showing the configuration of an apparatus used to carry out an example of the embodiment of the method of the present invention.

FIG. 3 is a diagram illustrating a power spectrum (sound pressure spectrum) on a frequency axis obtained by performing a Fourier transform on an acoustic signal obtained by installing a microphone at a position P1 in FIG. 1A and simultaneously collecting sounds generated from four valves. FIG.

FIG. 4A is a diagram illustrating an example of an acoustic signal;
(B) is a diagram showing an example of a filtered signal in which one type of acoustic waveform AW corresponding to a frequency component of a sound emitted from one valve on the time axis is clearly shown by the filtering process,
(C) is one of the vibration detection sensors provided corresponding to the valve serving as the source of the acoustic waveform AW shown in FIG. 4 (B) among the outputs of the vibration detection sensors 12 to 15 in FIG. FIG. 4 is a diagram illustrating a time waveform of an output, that is, a vibration signal.

FIGS. 5 (1) to (9) are waveform diagrams used to explain selection of a filter band in filter processing.

6 (1) to 6 (4) are vibration signals obtained from the vicinity of four valves 6 to 9 obtained from the vibration detection sensors 12 to 15 in FIG. 2, respectively, and FIG. It is a figure of the filter processing signal containing the acoustic waveform corresponding to the frequency component of the sound from four valves obtained from the acoustic signal.

FIG. 7 is an explanatory diagram used to explain a diagnosis method when performing an abnormality diagnosis of an operation unit using an acoustic waveform.

FIGS. 8A to 8D are diagrams used to explain a method of diagnosing an abnormality of a valve (operating unit) from a correlation function between a reference acoustic waveform and an acoustic waveform.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Motor 2-5 Cylinder 6-9 Valve 10 Microphone 12-15 Vibration detection sensor 20 Data recorder 21 Filter device 22 Data analyzer 23 Speaker

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Teruo Hioki 2-1-1, Tsurumichuo, Tsurumi-ku, Yokohama-shi, Kanagawa Prefecture Inside Chiyoda Kako Construction Co., Ltd. 1-chome No. 1 F-term in Chiyoda Chemical Construction Co., Ltd. (reference) 2G064 AA01 AB01 AB13 AB22 BD17 CC03 CC41 CC54 3H045 AA03 AA12 AA25 BA41 CA22 EA12 EA17 EA26 EA36 EA38 FA17 FA23 FA24 3H065 CA01 CA04 5H223 AE05

Claims (7)

[Claims] 1. A method of converting sound generated from a device having a plurality of operation units into an audio signal by a microphone and diagnosing an abnormality of the plurality of operation units based on the audio signal, 1 corresponding to a frequency component of a sound emitted from the at least one operation unit on a time axis after filtering.
Generating at least one filtered signal in which more than one kind of acoustic waveform clearly appears; identifying timings on the time axis of sounds generated from the plurality of operation units; and Specifying the acoustic waveform corresponding to the frequency component of the sound generated from the operating unit to be diagnosed from the filtered signal, and generating an abnormality in the operating unit to be diagnosed based on the acoustic waveform A method for diagnosing an abnormality in an operation unit, which comprises diagnosing whether or not there is an error. 2. A method of converting sound generated from a device having a plurality of operation units into an audio signal by a microphone and diagnosing an abnormality of the plurality of operation units based on the audio signal, Filter processing is performed to generate one filtered signal in which a plurality of types of acoustic waveforms corresponding to frequency components of sound emitted from the at least one operating unit clearly appear on a time axis, and are generated from the plurality of operating units, respectively. Specifying the timing on the time axis of the sound to be performed, specifying the acoustic waveform corresponding to the sound generated from the operating unit to be diagnosed from the filtered signal based on the timing, A method for diagnosing an abnormality in an operation unit, comprising: diagnosing whether an abnormality has occurred in the operation unit to be diagnosed on the basis of the abnormality. 3. A method for converting a sound generated from a device having n operating units into an acoustic signal with a microphone and diagnosing an abnormality of the n operating units based on the acoustic signal, The microphones were arranged at n measurement positions respectively corresponding to the three operation units, and n types of the acoustic signals were collected. Filter processing was performed on each of the n types of acoustic signals to correspond to the time axis. The operating unit generates n types of filtered signals in which an acoustic waveform corresponding to a frequency component of a sound emitted from the operating unit clearly appears, and responds based on the acoustic waveform included in the n types of filtered signals. A method for diagnosing whether an abnormality has occurred in the operating section. 4. The method according to claim 1, wherein each of the plurality of operation units sets the acoustic waveform obtained in a normal state in advance as a reference acoustic waveform, and compares the reference acoustic waveform with the acoustic waveform included in the filter processing signal. 4. The method for diagnosing abnormality of an operation unit according to claim 1, wherein the operation unit to be diagnosed is diagnosed as to whether an abnormality has occurred. 5. A reference acoustic waveform in which each of the plurality of operating units is obtained in a normal state in advance, and a correlation function between the reference acoustic waveform and the filter processing signal is obtained. The abnormality diagnosis method for an operation unit according to claim 1, 2, or 3, wherein it is diagnosed whether an abnormality has occurred in the operation unit to be diagnosed. 6. A change in the amplitude of the acoustic waveform, a change in the average value of the amplitude, a change in the peak value of the amplitude, a change in the frequency bandwidth of the filter required for the extraction, a change in the cutoff frequency of the filter required for the extraction, Whether an abnormality has occurred in the operation unit to be diagnosed based on at least one of the attenuation tendency of the acoustic waveform, a change in the time interval of occurrence of the acoustic waveform, and a correlation function between a reference acoustic waveform and the acoustic waveform. 4. The method for diagnosing an abnormality of an operation unit according to claim 1, wherein the diagnosis is performed. 7. The method according to claim 1, 2, 3, 4, or 5, for diagnosing an abnormality of the plurality of valves of a compressor having a plurality of valves that open and close at predetermined time intervals. A method for diagnosing a valve abnormality of a compressor.