Threshold value setting device, abnormality determination device, threshold value setting method, and abnormality determination method

Abstract

To provide a threshold value setting device that sets a threshold value for easily determining an abnormality or the like of a device.SOLUTION: A threshold value setting device 4 comprises: an input unit 41 that inputs a period of data extracted from the acquired data; a data extraction unit 42 that extracts the period of data input by the input unit 41; a reference value determination unit 43 that determines a reference value from the data extracted by the data extraction unit 42; and a threshold value calculation unit 44 that calculates a threshold value from the reference value determined by the reference value determination unit 43.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a threshold setting device that sets a threshold for determining an abnormality or the like in an apparatus, an abnormality determination device that determines an abnormality in an apparatus, a threshold setting method that sets a threshold for determining an abnormality or the like in an apparatus, and an abnormality determination method that determines an abnormality in an apparatus. [Background technology]

[0002] Conventionally, an equipment diagnosis device capable of diagnosing an operating state based on a state quantity of an equipment in a normal state, a state quantity of an abnormal state, and a preset threshold value between these state quantities, and detecting an abnormality or predicting the timing of an abnormality has been disclosed (see Patent Document 1). Also disclosed is an abnormality detection device that judges an abnormality in a bearing by comparing with a threshold value (see Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4396286 [Patent Document 2] Patent No. 6942836 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the thresholds used to determine equipment anomalies were often set by humans based on past measurements and experience. As a result, there were discrepancies in abnormality determinations depending on the person who set them. Setting the thresholds for abnormality determination requires a lot of information and complex calculations, so it is not easy to set the thresholds, and it is not possible to easily determine abnormalities.

[0005] In view of the above problems, the present invention aims to provide a threshold setting device that sets a threshold for easily determining abnormalities in equipment, an abnormality determination device that determines abnormalities in equipment, a threshold setting method that sets a threshold for easily determining abnormalities in equipment, and an abnormality determination method that determines abnormalities in equipment. [Means for solving the problem]

[0006] In order to achieve the above object, a threshold setting device according to one aspect of the present invention comprises: an input section for inputting a period of data to be extracted from the acquired data; a data extraction unit that extracts the data for the period input by the input unit; a reference value determination unit that determines a reference value from the data extracted by the data extraction unit; a threshold calculation unit that calculates a threshold from the reference value determined by the reference value determination unit; Equipped with. Effect of the Invention

[0007] According to one embodiment of the present invention, a threshold setting device, an abnormality determination device, a threshold setting method, and an abnormality determination method can easily and quickly set a threshold for determining abnormalities in equipment, and further, can easily and quickly determine abnormalities in the equipment without complex calculations or based on a large amount of information.

[0008] Other objects, configurations and effects will become apparent from the detailed description of the invention described below. [Brief description of the drawings]

[0009] [Figure 1] 1 is an overall configuration diagram showing an example of an abnormality determination system according to a first embodiment. [Diagram 2] 4A to 4C are diagrams illustrating an abnormality determination according to the present embodiment. [Diagram 3] FIG. 2 is a hardware configuration diagram showing an example of a computer. [Figure 4] 1 is a flowchart illustrating an example of a threshold setting method according to the present embodiment. [Diagram 5] 4 is a flowchart showing an example of an abnormality determination method according to the present embodiment. [Figure 6] 4 shows another example of the device according to the first embodiment. [Figure 7] 4 shows another example of the device according to the first embodiment. [Figure 8] 1 shows an example of a device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment for carrying out the present invention will be described with reference to the drawings. In the following, the scope necessary for the explanation to achieve the object of the present invention will be shown in a schematic manner, and the scope necessary for the explanation of the relevant part of the present invention will be mainly explained, and the parts that are omitted from the explanation will be based on the publicly known technology.

[0011] (Explanation of the overall configuration) FIG. 1 is a diagram showing an overall configuration of an example of an abnormality determination system 1 according to the first embodiment.

[0012] The abnormality determination system 1 of the first embodiment includes an equipment 2 that is to be subjected to abnormality determination, a vibration sensor 3 that measures vibrations of the equipment 2 and outputs vibration data, a threshold setting device 4 that sets a threshold for determining an abnormality, and an abnormality determination device 5 that determines an abnormality in the equipment 2 by comparing the vibration data measured by the vibration sensor 3 with the threshold set by the threshold setting device 4.

[0013] As an example of the first embodiment, an equipment 2 used in the abnormality judgment system 1 has a motor 21 that generates a driving force, a pump 22 driven by the motor 21, and a transmission unit 23 that transmits the driving force generated by the motor 21 to the pump 22.

[0014] The motor 21 is connected to a power source (not shown) to operate. When the motor 21 rotates, the transmission unit 23 transmits the rotational force to the pump 22, and the pump 22 operates. Vibrations are generated from at least one of the motor 21, the pump 22, and the transmission unit 23.

[0015] The vibration sensor 3 is installed in, for example, at least one of the motor 21, the pump 22, or the transmission unit 23. The vibration sensor 3 may be of either a contact type such as a piezoelectric type, an electromagnetic type, or a capacitance type, or a non-contact type such as a laser Doppler type. The vibration sensor 3 may measure any of acceleration, velocity, and displacement.

[0016] (Explanation about threshold settings) The threshold setting device 4 has an input unit 41 that inputs a data extraction period, a data extraction unit 42 that extracts data for the extraction period set by the input unit 41, a reference value determination unit 43 that determines a reference value for the data extracted by the data extraction unit 42, and a threshold calculation unit 44 that calculates a threshold from the reference value determined by the reference value determination unit 43.

[0017] The input unit 41 inputs an extraction period to be extracted in order to determine a threshold value from the time series data of vibration measured by the vibration sensor 3. The data extraction period may be set so that the data extraction period is automatically determined by programming or the like according to the time when the device 2 is operated, and input from the input unit 41. The data extraction period may also be determined in advance.

[0018] The data extraction unit 42 extracts vibration data for the extraction period set by the input unit 41. In this embodiment, the vibration data is obtained by a data acquisition unit 51 (described later) that acquires data measured by the vibration sensor 3. The data extraction unit 42 may extract the data from the vibration data acquired and stored by the data acquisition unit 51.

[0019] The reference value determination unit 43 determines a reference value for the data extracted by the data extraction unit 42. The reference value may be the median, mode, average, etc. of the extracted data. The reference value may be changed depending on the number of extracted data. For example, if the number of extracted data is greater than a predetermined number, the median may be used, and if the number of extracted data is less than the predetermined number, the mode may be used. In this way, a statistically stable reference value can be obtained depending on the number of extracted data.

[0020] The threshold calculation unit 44 calculates the threshold from the reference value determined by the reference value determination unit 43. In this embodiment, the threshold calculation unit 44 calculates the threshold by multiplying the reference value determined by the reference value determination unit 43 by a predetermined coefficient. The threshold may be calculated not only by multiplication of the reference value, but also by calculations such as addition and subtraction, or a combination of multiple calculations. The threshold may also be set to be smaller than the reference value.

[0021] The threshold calculation unit 44 is not limited to one threshold, and may calculate two or more thresholds. In this case, the threshold calculation unit 44 calculates a first threshold and a second threshold that is farther away from the reference value than the first threshold. The threshold calculation unit 44 may calculate the first threshold and the second threshold by performing at least one of adding, subtracting, or multiplying an arbitrary coefficient to the reference value.

[0022] In this way, the threshold setting device 4 can quickly set a threshold for determining an abnormality or the like in the device 2 in a simple manner.

[0023] (Explanation of abnormality judgment) FIG. 2 is a diagram illustrating the abnormality determination in this embodiment.

[0024] The abnormality judgment device 5 has a data acquisition unit 51 that acquires vibration data measured by the vibration sensor 3, a judgment unit 52 that compares the vibration data acquired by the data acquisition unit 51 with a threshold value set by the threshold setting device 4 to judge an abnormality in the equipment 2, and an output unit 53 that outputs the result of the judgment made by the judgment unit 52.

[0025] The data acquisition unit 51 acquires vibration data measured by the vibration sensor 3. For example, the data acquisition unit 51 acquires data such as the acceleration of the device 2 as shown in Fig. 2. The data acquisition unit 51 preferably stores the vibration data acquired at least during a predetermined determination period. Note that the data acquisition unit 51 may have a separate storage unit (not shown) for storing the vibration data acquired by the data acquisition unit 51.

[0026] The judgment unit 52 compares the vibration data acquired by the data acquisition unit 51 with the threshold value set by the threshold setting device 4 to judge the state of the device 2. It is preferable to use a statistically processed value, such as a median value, a mode value, or an average value, of the vibration data for a predetermined judgment period, taking into account temporary errors.

[0027] For example, as shown in FIG. 2, the determination unit 52 of this embodiment determines the state of the device 2 as "normal" until the vibration data exceeds the first threshold, and determines the state of the device 2 as "abnormal" when the vibration data exceeds the first threshold in a predetermined determination period. Furthermore, the determination unit 52 of this embodiment determines the state of the device 2 as "damaged" when the vibration data exceeds the second threshold in a predetermined determination period. Furthermore, even if the vibration data subsequently becomes equal to or less than the second threshold, the determination unit 52 of this embodiment continues to determine the state of the device 2 as "damaged" as indicated by the two-dot chain line in FIG. 2. The determination contents such as "normal", "abnormal", or "damaged" are merely examples, and the determination contents may be changed to other terms such as "caution" or "warning" as appropriate depending on the target device, etc.

[0028] The determination unit 52 may determine the state of the device 2 as "abnormal" when the vibration data temporarily exceeds the first threshold. The determination unit 52 may determine the state of the device 2 as "damaged" when the vibration data temporarily exceeds the second threshold. The determination unit 52 may change the determination of "abnormal" to "normal" when the vibration data becomes equal to or less than the first threshold after the state of the device 2 has once been determined to be "abnormal". The determination unit 52 may change the determination of "damage" to "abnormal" when the vibration data exceeds the first threshold and becomes equal to or less than the second threshold after the state of the device 2 has once been determined to be "damaged". In the case where there is one threshold, the determination of "abnormal" may continue even if the vibration data becomes equal to or less than the first threshold after the state of the device 2 has been determined to be "abnormal".

[0029] The output unit 53 outputs the result of the determination made by the determination unit 52. For example, as shown in Fig. 2, the output unit 53 of this embodiment outputs vibration data, a reference value, a threshold value, a determination result, etc. Note that it is sufficient for the output unit 53 to output at least one of the vibration data, the reference value, the threshold value, and the determination result.

[0030] In this embodiment, the device 2 has a motor 21 and a pump 22 and generates vibrations. However, the device 2 is not limited to this, and may be a refrigerator, a gas machine, various machine tools, a press machine, a conveying machine, a diagnostic machine, etc. Furthermore, the data acquired to determine an abnormality is not limited to vibration, and may be rotation speed, load, current value, voltage value, moving speed, moving amount, etc. In this case, the sensor used is not limited to the vibration sensor 3, and may be a rotation sensor, load sensor, ammeter, voltmeter, speedometer, displacement meter, etc. according to each data.

[0031] In this way, according to the abnormality determination device 5, a threshold for determining whether or not an abnormality has occurred in the device 2 can be set in a simple and rapid manner, and further, whether or not an abnormality has occurred in the device 2 can be determined in a simple and rapid manner.

[0032] (Hardware configuration of each device) 3 is a hardware configuration diagram showing an example of the computer 900. The abnormality determination device 5 including the threshold setting device 4 is configured by a general-purpose or dedicated computer 900.

[0033] 3, the computer 900 includes, as its main components, a bus 910, a processor 912, a memory 914, an input device 916, an output device 917, a display device 918, a storage device 920, a communication I / F (interface) unit 922, an external device I / F unit 924, an I / O (input / output) device I / F unit 926, and a media input / output unit 928. Note that the above components may be omitted as appropriate depending on the application of the computer 900.

[0034] The processor 912 is composed of one or more arithmetic processing devices (such as a central processing unit (CPU), a micro-processing unit (MPU), a digital signal processor (DSP), a graphics processing unit (GPU), or a neural processing unit (NPU)) and operates as a control unit that controls the entire computer 900. The memory 914 stores various data and programs 930, and is composed of, for example, a volatile memory (DRAM, SRAM, etc.) that functions as a main memory, a non-volatile memory (ROM), a flash memory, etc.

[0035] The input device 916 is, for example, a keyboard, a mouse, a numeric keypad, an electronic pen, etc., and functions as the input unit 41. The output device 917 is, for example, a sound (audio) output device, a vibration device, etc., and functions as the output unit 53. The display device 918 is, for example, a liquid crystal display, an organic EL display, electronic paper, a projector, etc. The input device 916 and the display device 918 may be integrated together, such as a touch panel display. The storage device 920 is configured with, for example, an HDD, an SSD, etc., and functions as a memory unit. The storage device 920 stores various data required for the execution of the operating system and the program 930.

[0036] The communication I / F unit 922 is connected to a network 940 such as the Internet or an intranet by wire or wirelessly, and functions as a communication unit that transmits and receives data to and from other computers according to a predetermined communication standard. The external device I / F unit 924 is connected to an external device 950 such as a camera, a printer, a scanner, a reader / writer by wire or wirelessly, and functions as a communication unit that transmits and receives data to and from the external device 950 according to a predetermined communication standard. The I / O device I / F unit 926 is connected to an I / O device 960 such as various sensors and actuators, and functions as a communication unit that transmits and receives various signals and data, such as detection signals from sensors and control signals to actuators, between the I / O device 960. The media input / output unit 928 is composed of, for example, a drive device such as a DVD drive or a CD drive, a memory card slot, and a USB connector, and reads and writes data from and to a medium (non-temporary storage medium) 970 such as a DVD, a CD, a memory card, or a USB memory.

[0037] In the computer 900 having the above configuration, the processor 912 calls up the program 930 stored in the storage device 920 into the memory 914, executes the program, and controls each unit of the computer 900 via the bus 910. The program 930 may be stored in the memory 914 instead of the storage device 920. The program 930 may be recorded in the medium 970 in an installable file format or an executable file format, and provided to the computer 900 via the media input / output unit 928. The program 930 may be provided to the computer 900 by downloading it via the network 940 via the communication I / F unit 922. In addition, the computer 900 may realize various functions realized by the processor 912 executing the program 930, for example, with hardware such as a field-programmable gate array (FPGA) or an application specific integrated circuit (ASIC).

[0038] The computer 900 is, for example, a stationary computer or a portable computer, and is an electronic device of any type. The computer 900 may be a client computer, a server computer, a cloud computer, or an embedded computer called, for example, a control panel, a controller (including a microcomputer, a programmable logic controller, and a sequencer). The computer 900 may be applied to devices other than the abnormality determination device 5 including the threshold setting device 4 of this embodiment.

[0039] The abnormality determination device 5 including the threshold setting device 4 of this embodiment is configured by each unit of a computer 900. For example, the input unit 41 is configured by an input device 916, the output unit 53 is configured by an output device 917 and a display device 918, the data acquisition unit 51 is configured by a communication I / F unit 922, an external device I / F unit 924, an I / O device I / F unit 926, a memory 914 or a storage device 920, the data extraction unit 42, the reference value determination unit 43, the threshold calculation unit 44, and the determination unit 52 are configured by a processor 912.

[0040] (Threshold setting method) FIG. 4 is a flowchart showing an example of a threshold setting method according to the present embodiment.

[0041] In the threshold setting method, first, in step 1, an extraction period is input from the input unit 41 (S1). The extraction period in this embodiment is the period from February 20 to March 5 of the period shown in FIG. Then, in step 2, the data extraction unit 42 extracts vibration data for the extraction period set by the input unit 41 (S2). Next, in step 3, the reference value determination unit 43 determines whether the number of extracted data is equal to or greater than a predetermined number (S3).

[0042] In step 3, if the number of data extracted by the reference value determination unit 43 is equal to or greater than a predetermined number, in step 4, the reference value determination unit 43 calculates the median of the data (S4). In step 3, if the number of data extracted by the reference value determination unit 43 is less than the predetermined number, in step 5, the reference value determination unit 43 calculates the mode of the data (S5).

[0043] Next, in step 6, the reference value determination unit 43 calculates the reference value (S6). In this embodiment, when the number of data is equal to or greater than a predetermined number, the median of the data is used as the reference value, and when the number of data is less than the predetermined number, the most frequent value of the data is used. As shown in FIG. 2, the reference value in this embodiment is the median acceleration of the extraction period from February 20 to March 5, which is approximately 11 m / s 2 It is.

[0044] Next, in step 7, the threshold calculation unit 44 calculates the first threshold (S7). The first threshold in this embodiment is calculated by multiplying a reference value by a predetermined coefficient. As shown in FIG. 2, the first threshold in this embodiment is calculated by multiplying a reference value of 11 m / s 2 Multiplied by a factor of 2.1, this is approximately 23m / s 2 It is.

[0045] Next, in step 8, the threshold calculation unit 44 calculates the second threshold (S8). The second threshold in this embodiment is calculated by multiplying the reference value by a predetermined coefficient. As shown in FIG. 2, the second threshold in this embodiment is calculated by multiplying the reference value by a predetermined coefficient. 2 Multiplying this by a factor of 4.5 gives approximately 49.5m / s 2 It is.

[0046] Next, in step 9, the threshold calculation unit 44 sets a threshold (S9). As shown in Fig. 2, the first threshold is used to detect an abnormality, and the second threshold is used to detect damage. If only the stage of an abnormality is to be detected, it is possible to set only the first threshold and not the second threshold. In this case, it is not necessary to calculate the second threshold in step 8.

[0047] In this way, according to the threshold setting method, the threshold for determining an abnormality or the like in the device 2 can be set quickly and easily.

[0048] (Abnormality determination method) FIG. 5 is a flowchart showing an example of the abnormality determination method according to the present embodiment.

[0049] In the anomaly determination method, first, in step 11, the data acquisition unit 51 acquires measurement data from the vibration sensor 3 (S11). In this embodiment, the measurement data is a value obtained by performing statistical processing such as an average value, a median value, or a mode value of time-series data for a predetermined determination period, taking into account temporary errors. Note that the measurement data may be a single piece of data that is not subjected to statistical processing.

[0050] Next, in step 12, the determination unit 52 determines whether or not the measurement data acquired by the data acquisition unit 51 is greater than a first threshold value (S12). If the measurement data acquired by the data acquisition unit 51 is greater than the first threshold value in step 12, the determination unit 52 determines whether or not the measurement data acquired by the data acquisition unit 51 is greater than a second threshold value in step 13 (S13).

[0051] In step 13, if the measurement data acquired by the data acquisition unit 51 is greater than the second threshold, in step 14, the output unit 53 outputs information that the measurement data exceeds the second threshold, in this embodiment, information that the state of the device 2 is "damaged" (S14). In step 13, if the measurement data acquired by the data acquisition unit 51 is equal to or less than the second threshold, in step 15, the output unit The output unit 53 outputs information that the measurement data exceeds the first threshold value, that is, information that the state of the device 2 is "abnormal" in this embodiment (S15).

[0052] In addition, in step 12, if the measurement data acquired by the data acquisition unit 51 is equal to or less than the first threshold value, in step 16, the output unit 53 outputs information that the measurement data does not exceed the threshold value, in this embodiment, information that the status of the device 2 is “normal” (S16).

[0053] In this way, the abnormality determination device 5 can determine whether or not an abnormality has occurred in the device 2 easily and quickly.

[0054] (Another example of the device 2 according to the first embodiment) Fig. 6 shows another example of the device 2 of the first embodiment. Fig. 6(a) shows an example in which the vibration sensor 3 is installed on the accessory 24 of the pump 22, and Fig. 6(b) shows an example in which the vibration sensor 3 is installed on the device 2 in which the motor 21 and the pump 22 are directly connected.

[0055] As shown in Fig. 6(a), the abnormality determination system 1 of this embodiment may install a vibration sensor 3 in an accessory 24 other than the motor 21, the pump 22, or the transmission unit 23, and detect vibrations of the accessory 24. Also, as shown in Fig. 6(b), the abnormality determination system 1 of this embodiment may not use the transmission unit 23, but install a vibration sensor 3 in the device 2 to which the motor 21 and the pump 22 are directly connected, and detect vibrations.

[0056] (Another example of the device 2 according to the first embodiment) FIG. 7 shows another example of the device 2 according to the first embodiment.

[0057] 7, the abnormality determination system 1 of this embodiment may be used in a device 2 in which a motor 21 and a pump 22 are installed in a vertical direction. A transmission unit 23 may be installed between the motor 21 and the pump 22, or the motor 21 and the pump 22 may be directly connected without installing the transmission unit 23.

[0058] (An example of the device 2 according to the second embodiment) Fig. 8 shows an example of the device 2 of the second embodiment. Fig. 8(a) shows an example in which a vibration sensor 3 is installed on the device 2 that transmits the driving force of the motor 21 to the fan 25, and Fig. 8(b) shows an example in which a vibration sensor 3 is installed on the device 2 that transmits the driving force of the motor 21 to the coaxial fan 25.

[0059] As shown in FIG. 8, the abnormality determination system 1 of this embodiment may use an apparatus 2 having a motor 21 that generates a driving force, a fan 25 that is driven by the motor 21, and a transmission unit 23 that transmits the driving force generated by the motor 21 to the fan 25.

[0060] In the device 2 shown in Fig. 8(a), the motor 21 and the fan 25 rotate about different axes, and a transmission unit 23 such as a belt or gear transmits the driving force. In the device 2 shown in Fig. 8(b), the motor 21 and the fan 25 rotate on the same axis, and a transmission unit 23 such as a coupling, joint, or the like transmits the driving force.

[0061] In this way, the threshold setting device 4 and the abnormality determination device 5 of this embodiment can be used in various types of devices 2. For example, although not shown, the devices 2 can be used in refrigerators, gas machines, various machine tools, press machines, conveying machines, diagnostic machines, etc. Furthermore, the data acquired to set the threshold and determine an abnormality is not limited to vibration, and may be rotation speed, load, current value, voltage value, moving speed, moving amount, etc. In this case, the sensor used is not limited to the vibration sensor 3, and may be a rotation sensor, load sensor, ammeter, voltmeter, speedometer, displacement meter, etc. according to each data.

[0062] The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention, all of which are included in the technical concept of the present invention. [Explanation of symbols]

[0063] 1...abnormality determination system, 2...equipment, 21...motor, 22...pump, 23...transmission unit, 24...accessory, 25...fan 3...Vibration sensor, 4... threshold setting device, 41... input unit, 42... data extraction unit, 43... reference value determination unit, 44... threshold calculation unit, 5...abnormality determination device, 51...data acquisition unit, 52...determination unit, 53...output unit

Claims

1. an input unit for inputting a period of data to be extracted from the acquired data; a data extraction unit for extracting the data of the period input by the input unit; a reference value determination unit for determining a reference value from the data extracted by the data extraction unit; a threshold calculation unit for calculating a threshold from the reference value determined by the reference value determination unit; comprising wherein the reference value determination unit determines the most frequent value or the median value of the data extracted by the data extraction unit as the reference value, uses the median value of the data when the number of the data extracted by the data extraction unit is equal to or more than a predetermined number, and uses the most frequent value of the data when the number of the data extracted by the data extraction unit is less than the predetermined number a threshold setting device; a data acquisition unit for acquiring data of a device and causing the data extraction unit to extract the data; a determination unit for comparing a value obtained by performing statistical processing on the data acquired by the data acquisition unit, which is the median value, the most frequent value, or the average value of the data of a predetermined determination period, with the threshold set by the threshold setting device, and determining the state of the device; an output unit for outputting the result determined by the determination unit; comprising an abnormality determination device.

2. The threshold calculation unit calculates the threshold by performing at least one calculation of addition, subtraction, multiplication, or division of an arbitrary coefficient with respect to the reference value. The abnormality determination device according to claim 1.

3. The threshold is smaller than the reference value. The abnormality determination device according to claim 2.

4. The threshold calculation unit calculates a first threshold and a second threshold that deviates from the reference value more than the first threshold. The abnormality determination device according to claim 1.

5. The threshold calculation unit calculates the first threshold and the second threshold by performing at least one calculation of addition, subtraction, multiplication, or division of an arbitrary coefficient with respect to the reference value. The abnormality determination device according to claim 4.

6. a step of inputting a period of data to be extracted from the acquired data; a step of extracting the data of the input period from the acquired data; a step of determining a reference value from the data of the extracted period; a step of calculating a threshold from the determined reference value; having wherein the step of determining the reference value determines the most frequent value or the median value of the data of the extracted period as the reference value, uses the median value of the data when the number of the data of the extracted period is equal to or more than a predetermined number, and uses the most frequent value of the data when the number of the data of the extracted period is less than the predetermined number a threshold setting method A step of acquiring data of the machine, A step of comparing the data with a value obtained by performing statistical processing using the median, the mode, or the average value of the data for a predetermined determination period as the data, and the threshold value set by the threshold value setting method to determine the state of the machine, A step of outputting the determined result, Having An abnormality determination method.

7. Calculating the threshold value by performing at least one calculation of addition, subtraction, multiplication, or division of an arbitrary coefficient with respect to the reference value The threshold value setting method abnormality determination method according to claim 6.

8. The threshold value is smaller than the reference value The abnormality determination method according to claim 7.

9. The threshold value calculates a first threshold value and a second threshold value that deviates from the reference value more than the first threshold value The abnormality determination method according to claim 6.

10. Calculating the first threshold value and the second threshold value by performing at least one calculation of addition, subtraction, multiplication, or division of an arbitrary coefficient with respect to the reference value The abnormality determination method according to claim 9.

Images