JP2021121788A - Diagnostic device, diagnostic method, diagnostic program, and diagnostic system - Google Patents

Abstract

To provide a technique for accurately detecting wear of a machine.SOLUTION: A diagnostic device includes: an integration section for integrating measurement values of a vibration sensor arranged in a machine; an initialization section for changing an integration value into an initial value when an integration value of the integration section reaches a predetermined integration value; a clock section for clocking an arrival time to be required for a change of an integration value from the initial value to the predetermined integration value; and a determination section for determining a state of the machine with the use of a difference between respective arrival times.SELECTED DRAWING: Figure 5

Description

The present invention relates to diagnostic devices, diagnostic methods, diagnostic programs and diagnostic systems.

Various equipment such as air conditioning equipment, production equipment, and power generation equipment are equipped with machines having operating parts such as a rotating mechanism and a linear motion mechanism. Bearings, guide rails, and the like are usually used for such operating parts. Mechanical parts such as bearings and guide rails gradually wear out due to deterioration over time.

The vibration during operation of machinery gradually changes according to the progress of wear of bearings, guide rails, and the like. For this reason, machine vibration is usually listed as a monitoring item in daily inspections, and is one of the typical monitoring items in a diagnostic device using sensors (for example, Patent Documents 1 to 3). reference).

JP-A-2018-155543 Japanese Unexamined Patent Publication No. 2018-54587 Japanese Patent No. 4283391

A diagnostic device that monitors the vibration of a machine with a vibration sensor usually issues an alarm when the frequency or amplitude of the machine vibration obtained by the vibration sensor reaches a set value. Such set values are set according to the measured values at normal times, the characteristics of the machine, and the like. However, in this method, an alarm cannot be issued unless the measured value reaches the set value. Therefore, in this method, it is difficult to grasp the aged deterioration due to the gradual progress of wear. In addition, there is a possibility that a frequency or amplitude that fluctuates due to factors other than wear of machine parts may be erroneously detected as an abnormality of the machine.

Therefore, it is conceivable to monitor the rate of change in the frequency and amplitude of mechanical vibration and issue an alarm when the rate of change exceeds the threshold value. However, the vibration sensor installed in the machine may detect the sudden vibration applied to the machine. Therefore, in the method of monitoring the rate of change, if the threshold value is made small, there is a high possibility that the diagnostic device will issue an alarm every time the vibration sensor detects vibration generated by a factor other than the wear of such mechanical parts, which is troublesome. .. Further, even when the threshold value is reduced, it is highly possible that the rate of change does not exceed the threshold value because the rate of change does not change significantly in the case of wear that progresses slowly.

Therefore, it is an object of the present invention to provide a technique for accurately detecting wear of a machine.

In order to solve the above problems, in the present invention, the measured values of the vibration sensors installed in the machine are integrated, and the difference between the arrival times required for the integrated values to change from the initial value to the predetermined integrated value is used for the machine. I decided to judge the state.

Specifically, the present invention is a diagnostic device, in which an integrating unit that integrates the measured values of a vibration sensor installed in a machine and an integrating value that reaches a predetermined integrated value reaches an initial value. An initialization unit to be changed, a timekeeping unit that measures the arrival time required for the integrated value to change from the initial value to a predetermined integrated value, and a determination unit that determines the state of the machine using the difference between the arrival times. To be equipped.

Here, the predetermined integrated value is a value that is appropriately set in advance according to the content to be detected by the diagnostic apparatus. The initial value is a value at the start of integration, and is, for example, 0 (zero) or another appropriate value. The predetermined integrated value may be a preset value for detecting a long-term change in the vibration state of the machine.

Since the above diagnostic device uses the difference between the arrival times required for the integrated value of the measured value of the vibration sensor to change from the initial value to the predetermined integrated value, the temporary fluctuation of the measured value is integrated. Absorbed by. Then, since the diagnosis is performed using the arrival time required from the initial value to the predetermined integrated value, the temporary fluctuation other than the wear that gradually progresses in the machine is gradually progressed without being falsely detected as an abnormality of the machine. It is possible to accurately detect the wear of the machine.

The determination unit may determine the state of the machine based on whether or not the difference between the arrival times is equal to or greater than a predetermined threshold value. With such a determination, the determination process is easy.

Further, the determination unit may determine the state of the machine based on a coefficient representing the correlation between the load of the machine and the arrival time, which changes as the difference between the arrival times increases. With such a determination, the determination accuracy can be improved.

The present invention can also be grasped from the aspect of the method. For example, the present invention includes an integration process for integrating the measured values of a vibration sensor installed in a machine, an initialization process for changing the integrated value to an initial value when the integrated value in the integration process reaches a predetermined integrated value, and an integration process. It is a diagnostic method having a time timing process for measuring the arrival time required for a value to change from an initial value to a predetermined integrated value, and a determination process for determining a machine state using the difference between the arrival times. May be good.

The present invention can also be grasped from the aspect of the program. For example, the present invention includes an integration process for integrating the measured values of a vibration sensor installed in a machine, an initialization process for changing the integrated value to an initial value when the integrated value in the integration process reaches a predetermined integrated value, and an integration process. A diagnostic program that causes a computer to execute a timekeeping process that measures the arrival time required for a value to change from an initial value to a predetermined integrated value, and a judgment process that determines the state of a machine using the difference between each arrival time. It may be.

The present invention can also be grasped from the aspect of the system. For example, the present invention includes a vibration sensor installed in a machine and a diagnostic device connected to the vibration sensor. The diagnostic device has an integrating unit that integrates the measured values of the vibration sensor and an integrating value of the integrating unit. The difference between each arrival time, the initialization unit that changes the integrated value to the initial value when the integrated value is reached, and the timing unit that measures the arrival time required for the integrated value to change from the initial value to the predetermined integrated value. It may be a diagnostic system having a determination unit for determining the state of the machine using the above.

With the above-mentioned diagnostic device, diagnostic method, diagnostic program and diagnostic system, it is possible to accurately detect wear of a machine.

FIG. 1 is a diagram showing an example of a system configuration of a diagnostic system according to an embodiment. FIG. 2 is a diagram showing an example of a processing flow realized by a computer. FIG. 3 is a graph of time series data showing an example of vibration acceleration detected by a vibration sensor. FIG. 4 is a graph showing an example of how the integrated values of vibration acceleration are added. FIG. 5 is a graph showing an example of a change in the integrated value when the integrated value of the vibration acceleration is reset at the threshold value. FIG. 6 is a diagram showing a first example of the correlation between the outside air temperature and the arrival time. FIG. 7 is a diagram showing a second example of the correlation between the outside air temperature and the arrival time.

Hereinafter, embodiments of the present invention will be described. The embodiments shown below are examples of embodiments of the present invention, and the technical scope of the present invention is not limited to the following embodiments.

FIG. 1 is a diagram showing an example of a system configuration of the diagnostic system 1 according to the embodiment. As shown in FIG. 1, the diagnostic system 1 includes a computer 2 (an example of a "diagnostic device" in the present application) and a vibration sensor 3 connected to the computer 2 by wire or wirelessly. The computer 2 is a computer having a CPU 21, a memory 22, a storage 23, and a communication interface 24. By executing a computer program read from the storage 23 and expanded in the memory 22, various processes described later are executed. do. Further, the vibration sensor 3 is a piezoelectric vibration sensor having a piezoelectric element 31, a weight 32, a piezoelectric element 31 and a case 33 including the weight 32, and the case 33 and the weight 32 are formed in the case 33 that has been vibrated. The vibration is converted into an electric signal by the pressing force generated in the piezoelectric element 31 by the relative movement.

In FIG. 1, the electric pump 4 is illustrated as a diagnostic target of the diagnostic system 1. The electric pump 4 has a pump main body 41 provided in the middle of a piping path and an electric motor 42 connected to a rotating shaft of the pump main body 41 via a coupling 43. The pump body 41 is provided with a bearing 41b that rotatably supports the rotating shaft of the impeller in the casing 41a. Further, the electric motor 42 is provided with bearings rotatably supporting the rotating shaft of the rotor in the casing 42a on the pump side bracket 42b and the non-pump side bracket 42c, respectively. Therefore, the manager who manages the electric pump 4 checks in daily inspections the presence or absence of water leakage in the shaft seal portion of the pump body 41, the indicated value of the pressure gauge provided in the piping, and the presence or absence of abnormal operation noise. For example, the hearing rod is applied to the bearing 41b, the pump side bracket 42b, and the non-pump side bracket 42c to check the sound of the bearing. The diagnostic system 1 is a system used for the purpose of diagnosing the electric pump 4 on behalf of an administrator who cannot constantly monitor the electric pump 4. For example, a vibration sensor is attached to a bearing 41b, a pump side bracket 42b, and a non-pump side bracket 42c. It is used with 3 installed.

The diagnostic system 1 is not limited to such a diagnosis of the electric pump 4, and for example, an electric fan for flowing air, an electric compressor, a steam-driven pump or fan, a frequency converter (MG set), and the like. It can be applied to the diagnosis of machine tools equipped with generators, linear motion guide rails, etc., and various other machines.

When the computer 2 executes the computer program, the computer 2 realizes the following processing. FIG. 2 is a diagram showing an example of a processing flow realized by the computer 2. When the computer 2 executes the computer program, the computer 2 periodically and repeatedly realizes a series of processing flows from step S101 to step S115 shown in FIG. Hereinafter, the outline of the processing flow realized by the computer 2 will be described.

The computer 2 first receives the measurement data transmitted from the vibration sensor 3 (S).
101). That is, the computer 2 stores the measurement data transmitted from the vibration sensor 3 in the memory 22.

Next, the computer 2 integrates the measurement data transmitted from the vibration sensor 3 (S102). That is, the computer 2 reads the integrated value of the measurement data stored in the storage 23 into the memory 22, and adds the measured value of the measurement data received and processed in step S101 to the integrated value. Then, the computer 2 stores the value obtained by adding the measured value to the integrated value in the storage 23 as a new integrated value.

Next, the computer 2 determines whether or not the integrated value calculated in the process of step S102 is equal to or greater than a predetermined threshold value (corresponding to the “predetermined integrated value” in the present application) (S103). This threshold value is a value set in advance for detecting a long-term (several hours or days) change in the vibration state of the machine, and is determined according to, for example, the operating state of the electric pump 4 and the installation environment. Value. When a negative determination is made in this step S103, the computer 2 omits a series of processes from step S104 to step S115, and executes the processes after step S101 again.

When the computer 2 makes an affirmative determination in the process of step S103, the computer 2 then resets the integrated value (S104). That is, the computer 2 overwrites and saves the initial value 0 (zero) as the integrated value of the measurement data stored in the storage 23. The initial value may be any value other than 0 (zero).

After resetting the integrated value in step S104, the computer 2 calculates the arrival time (S105). The arrival time is the time required for the integrated value of the measurement data to change from 0 (zero) to the threshold value. The computer 2 refers to the data at the time when 0 (zero) is recorded in the measurement data stored in the storage 23, and sets the time when the integrated value is reset and the time when the integrated value reaches the threshold value. Calculate the arrival time from the difference. The computer 2 calculates this arrival time each time step S105 is executed.

The computer 2 calculates the arrival time in step S105, and then calculates the correlation coefficient (S106). The correlation coefficient is a value that quantitatively expresses the correlation between the items that affect the vibration of the machine to be monitored and the vibration output. The computer 2 calculates the correlation coefficient in step S106, and then determines the performance change using the calculated correlation coefficient (S107). The details of determining the performance change using the correlation coefficient will be described later.

After determining the performance change in step S107, the computer 2 determines whether or not the correlation coefficient calculated in step S106 is less than the predetermined threshold value (S108). This threshold value is a preset value, for example, a value determined in a trial run or the like.

When the affirmative determination is made in step S108, the computer 2 notifies the operator of the monitoring result indicating that the performance of the electric pump 4 has changed (S109). That is, the computer 2 sends the monitoring result data to the display device, the alarm device, and various other output devices, and notifies the operator of the monitoring result through these output devices. Then, after executing this step S109, the computer 2 omits a series of processes from step S111 to step S115, and executes the processes after step S101 again.

On the other hand, when the negative determination is made in step S108, the computer 2 determines the aged deterioration (S110). Then, the computer 2 calculates the standardized value after determining the aged deterioration in step S110 (S111). The standardized value is a generalized value of data showing the relationship between the vibration and the output and the items that affect the vibration of the machine to be monitored. and,
The computer 2 calculates the regression coefficient after calculating the standardized value in step S111 (S112).

The computer 2 determines whether or not the regression coefficient calculated in step S112 is equal to or greater than a predetermined threshold value (S113). This threshold value is a preset value, for example, a value empirically determined from many years of operation results.

When the affirmative determination is made in step S113, the computer 2 notifies the operator of the monitoring result indicating that the electric pump 4 has aged deterioration (S114). Then, after executing this step S114, the computer 2 executes the processes after step S101 again.

On the other hand, when the negative determination is made in step S113, the computer 2 notifies the operator of the monitoring result that the electric pump 4 is normal (S115). Then, after executing this step S115, the computer 2 executes the processes after step S101 again.

The outline of the processing flow realized by the computer 2 is as described above. Hereinafter, the details of the processing flow realized by the computer 2 will be described with reference to an example of the measured data.

FIG. 3 is a graph of time series data showing an example of vibration acceleration detected by the vibration sensor 3. When the vibration acceleration of the electric pump 4 detected by the vibration sensor 3 is measured at a sampling frequency of 100 kHz, for example, a waveform as shown in FIG. 3 can be obtained. Since the vibration is a reciprocating motion centered on a predetermined position, the graph of the time-series data of the vibration acceleration detected by the vibration sensor 3 is centered on 0 (zero) as shown in FIG. And draw a waveform that alternates between positive and negative values. Therefore, the integrated value obtained by simply adding the vibration acceleration detected by the vibration sensor 3 takes a value close to 0 (zero). Therefore, the computer 2 integrates the absolute value of the vibration acceleration detected by the vibration sensor 3 in the process of step S102. The integrated vibration acceleration may be an effective value, or may be an instantaneous value when the vibration acceleration is half-wave rectified.

FIG. 4 is a graph showing an example of how the integrated values of vibration acceleration are added. When the computer 2 integrates the absolute value of the vibration acceleration in the process of step S102, the integrated value calculated in the process of step S102 will continue to gradually increase as time elapses, as shown in FIG. The vibration acceleration detected by the vibration sensor 3 may show a relatively excessive pulse-like value (also called a whiskers), as seen in FIG. 3, for example. However, since the integrated value calculated in the process of step S102 is a value obtained by continuously adding the instantaneous value of the vibration acceleration, it can be said that the integrated value absorbs such a temporary fluctuation of the value. Then, the rate of increase of the integrated value calculated in the process of step S102 is proportional to the magnitude of the continuous vibration of the electric pump 4. That is, the rate of increase of the integrated value calculated in the process of step S102 is higher when the electric pump 4 continues to vibrate relatively large than when the electric pump 4 continues to vibrate relatively small. Therefore, the arrival time required from resetting the integrated value to reaching the threshold value is longer when the electric pump 4 continues to vibrate relatively large than when the electric pump 4 continues to vibrate relatively small. Becomes shorter.

FIG. 5 is a graph showing an example of a change in the integrated value when the integrated value of the vibration acceleration is reset at the threshold value. FIG. 5 illustrates a case where the integrated value is reset when the integrated value of the vibration acceleration ^{reaches 5000 m / s 2.} When the process of step S104 described above is performed, that is, when the integrated value of the vibration acceleration is reset by the threshold value, the integrated value calculated by the process of step S102 has a serrated waveform as shown in FIG. Become. Then, step S10
The arrival time Δτ calculated in the process of 5 is the length between adjacent peaks (also referred to as wave peaks) in the waveform shown in FIG.

Here, when the electric pump 4 continues to vibrate constantly, the arrival time τ is basically constant. However, when the vibration state of the electric pump 4 changes due to the wear of the parts used in the electric pump 4, the arrival time τ before the change of the vibration state and the arrival time τ after the change of the vibration state There will be a difference. Therefore, in the diagnostic system 1 of the present embodiment, it is determined that the electric pump 4 is abnormal based on the difference between the arrival times, that is, the difference between the arrival times before and after the change in the vibration state. However, if a difference occurs in the arrival time and it is uniformly regarded as an abnormality of the electric pump 4, an external factor such as a change in the operating state of the electric pump 4 due to a change in the outside air temperature is mistaken as an abnormality of the electric pump 4. Therefore, in the diagnostic system 1 of the present embodiment, the diagnostic accuracy of the electric pump 4 based on the difference in arrival time is improved by performing the processes of steps S106 to 108, 110 to 112 described above. ..

That is, in step S106, which is performed after calculating the arrival time, the computer 2 calculates the correlation coefficient necessary for determining the performance change of the electric pump 4. When the performance of the electric pump 4 deteriorates, it means a situation in which the ratio of the input to the output, that is, the efficiency η becomes low. The input here is an element that can change the vibration of the machine, that is, an item that affects the vibration. The output is a vibration output. When the efficiency η becomes low, the vibration of the electric pump 4 increases because a larger input is required to exert the same output. Then, as the vibration of the electric pump 4 increases, the above-mentioned arrival time τ becomes shorter. This change typically manifests over a wide range of partial load factors.

Therefore, when calculating the efficiency η of the electric pump 4, a measurement item having a high contribution rate to the ratio of the current output to the rated output of the electric pump 4 (partial load factor) is substituted as the current output of the electric pump 4. For example, when the electric pump 4 is a cold water supply pump of a district heat supply facility, the outside air temperature corresponds to this. Further, in the case of a utility pump for production in a factory, the operating rate of the manufacturing equipment corresponds to this. Since such an outside air temperature and the operating rate of the manufacturing apparatus have a high proportion of contributing to the current output of the electric pump 4, the “machine load” in the correlation between the machine load and the arrival time represented by the following correlation coefficient Can be used as an example.

For example, when the performance change of the electric pump 4 is detected from the correlation between the outside air temperature and the arrival time τ, the correlation coefficient between the outside air temperature and the arrival time τ is compared before and after the performance change. FIG. 6 is a diagram showing a first example of the correlation between the outside air temperature and the arrival time. When the electric pump 4 exhibits the normal performance before the performance deteriorates, the correlation between the outside air temperature θ and the arrival time τ is near the reference line shown as “normal performance” in FIG. While it is distributed in the area, after the performance deteriorates, it is distributed in the area indicated as "performance after change". That is, as shown in FIG. 6, after the performance deteriorates, the correlation between the outside air temperature θ and the arrival time τ is distributed at a position below the reference line. In other words, the correlation coefficient gradually decreases as the performance of the electric pump 4 deteriorates.

Therefore, the computer 2 compares the correlation coefficient calculated in step 106 with the predetermined threshold value in the process of step S107. Then, the computer 2 determines whether or not the correlation coefficient is less than the predetermined threshold value in the process of step S108, and executes the process of step S109 or step S110 according to the determination result.

As a result of determining the performance change as described above, the computer 2 determines that there is no problem in the performance change, and then determines the aged deterioration. Aged deterioration in a rotating device such as the electric pump 4 includes, for example, an increase in rotational torque. When the rotational torque increases due to deterioration of the bearing or the like, the vibration of the electric pump 4 increases because a larger input is required to exert the same output. Then, as the vibration of the electric pump 4 increases, the above-mentioned arrival time τ becomes shorter. Aged deterioration can be grasped by utilizing such a causal relationship. Then, when judging the deterioration over time, the measurement items having a high contribution rate to the ratio of the current output (partial load factor) to the rated output are standardized so that the same output can be compared. For example, when the electric pump 4 is a cold water supply pump of a district heat supply facility, the outside air temperature corresponds to this. Further, in the case of a utility pump for production in a factory, the operating rate of the manufacturing equipment corresponds to this.

FIG. 7 is a diagram showing a second example of the correlation between the outside air temperature and the arrival time. In FIG. 7, the arrival time τ is constant when the outside air temperature is θmin or less because the electric pump 4 is operating at the minimum flow rate. When the relationship between the outside air temperature θ and the arrival time τ can be specified from the measurement data, for example, the value Δτstd (standardized value) after the standardization of the arrival time τ is calculated by the following equation with the outside air temperature θmin as the reference point. ..
Δτstd = Δτ (1-α (θ-θmin) / (θmax-θmin))
Here, α: correction coefficient, α = 0 to 1

Then, the computer 2 uses the regression coefficient of the linear regression equation using Δτstd for the past 30 steps including the latest arrival time τ when determining the aged deterioration.
First-order regression equation: Δτcal = a + bN
Here, a: constant term, b: regression coefficient, N: number of monitoring steps (with the latest one as 0 step, -29 steps to 0 step)

Then, the computer 2 makes a determination in step S113 depending on whether or not the regression coefficient b is less than the predetermined threshold value β (threshold value of the regression coefficient), and performs the process of step S114 or step S115 according to the determination result. Run.

The details of the processing contents executed in the diagnostic system 1 are as described above.

In machine monitoring, for example, the effective value (RMS: root mean square) of data for a predetermined time is obtained, the peak rate (= peak value / effective value) is obtained, or frequency analysis such as FFT is performed. , It is conceivable to obtain the vibration value (power spectrum) for each frequency. Then, using the current instantaneous value or the ratio obtained by dividing the current instantaneous value by the value at the normal time (called the rate of increase from the normal time), the magnitude is compared with the threshold value, and it is normal depending on the degree of exceeding the threshold value. Attention ・ It is conceivable to judge abnormalities. Alternatively, it is conceivable to observe the change with time of the instantaneous value or the increase ratio, and if there is an increasing tendency, it is judged to be abnormal. However, with these methods, measurement data such as vibration acceleration obtained by the vibration sensor may fluctuate due to disturbances such as partial load factor of rotating equipment, dark vibration due to the installation environment, radio noise, and power supply noise. The diagnosis result may be different each time.

In this regard, in the diagnostic system 1 of the above embodiment, the measurement data of the vibration acceleration is integrated and the monitoring is performed using the integrated value. Therefore, the fluctuation of the measurement data due to such disturbance is absorbed by the integration. Will be done. Therefore, the diagnosis result does not change due to disturbance every time monitoring is performed.

The execution interval of the series of processing flows from step S101 to step S115, which the computer 2 periodically and repeatedly executes, is preferably shorter in consideration of the influence of the partial load factor and the disturbance on the determination accuracy. However, for example, when the vibration sensor 3 is a wireless vibration acceleration sensor with a built-in battery, the frequency of battery replacement is low (about once every two years) from the viewpoint of labor saving in maintenance work. Desirable from. Considering the specifications of a commercially available wireless vibration acceleration sensor, it is desirable that the well-balanced execution interval is, for example, about once every 10 minutes.

By the way, in the above-described embodiment, both the determination of the performance change and the determination of the aged deterioration are executed, but the computer 2 may execute only one of the two processes. Further, the computer 2 may omit both the determination of the performance change and the determination of the aged deterioration, and may determine that the electric pump 4 is abnormal when the arrival time difference Δτ becomes equal to or more than a predetermined threshold value.

Further, in FIG. 1, a state in which the diagnostic device 2 is installed near the electric pump 4 is shown, but even if the diagnostic device 2 is installed in the control room of the facility where the electric pump 4 is installed. Alternatively, it may be located in a monitoring facility, a data center, or the like located in a remote location.

1 ... Diagnostic system 2 ... Computer 21 ... CPU
22 ... Memory 23 ... Storage 24 ... Communication interface 3 ... Vibration sensor 31 ... Piezoelectric element 32 ... Weight 33 ... Case 4 ... Electric pump 41 ... Pump body 41a ... Casing 41b ... Bearing 42・ ・ Motor 42a ・ ・ Casing 42b ・ ・ Pump side bracket 42c ・ ・ Non-pump side bracket 43 ・ ・ Coupling

Claims (7)

An integrating unit that integrates the measured values of the vibration sensor installed in the machine,
When the integrated value of the integrated unit reaches a predetermined integrated value, an initialization unit that changes the integrated value to an initial value, and an initialization unit.
A timekeeping unit that measures the arrival time required for the integrated value to change from the initial value to the predetermined integrated value.
A determination unit for determining the state of the machine using the difference between the arrival times is provided.
Diagnostic device. The predetermined integrated value is a value set in advance for detecting a long-term change in the vibration state of the machine.
The diagnostic device according to claim 1. The determination unit determines the state of the machine based on whether or not the difference between the arrival times is equal to or greater than a predetermined threshold value.
The diagnostic device according to claim 1 or 2. The determination unit determines the state of the machine based on a coefficient representing the correlation between the load of the machine and the arrival time, which changes as the difference between the arrival times increases.
The diagnostic device according to any one of claims 1 to 3. An integration process that integrates the measured values of the vibration sensor installed in the machine, and
When the integrated value in the integrated process reaches a predetermined integrated value, the initialization process for changing the integrated value to the initial value and
Timekeeping processing that measures the arrival time required for the integrated value to change from the initial value to the predetermined integrated value, and
It has a determination process for determining the state of the machine using the difference between the arrival times.
Diagnostic method. An integration process that integrates the measured values of the vibration sensor installed in the machine, and
When the integrated value in the integrated process reaches a predetermined integrated value, the initialization process for changing the integrated value to the initial value and
Timekeeping processing that measures the arrival time required for the integrated value to change from the initial value to the predetermined integrated value, and
A computer is made to execute a determination process for determining the state of the machine using the difference between the arrival times.
Diagnostic program. The vibration sensor installed in the machine and
A diagnostic device connected to the vibration sensor is provided.
The diagnostic device is
An integrating unit that integrates the measured values of the vibration sensor and
When the integrated value of the integrated unit reaches a predetermined integrated value, an initialization unit that changes the integrated value to an initial value, and an initialization unit.
A timekeeping unit that measures the arrival time required for the integrated value to change from the initial value to the predetermined integrated value.
It has a determination unit for determining the state of the machine using the difference between the arrival times.
Diagnostic system.

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