JP2018073327A - Diagnosis system and diagnosis program for machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a diagnosis system and diagnosis program of a machine capable of diagnosing an operation state of a drive part to preliminarily detect an abnormality of the drive part and a sign of the abnormality in a machine having a drive part such as a machine tool.SOLUTION: A machine 3 in which a drive part 30 has a position detector 31 and a drive power detector 32 comprises: diagnosis means 11 for performing drive for diagnosis to drive the drive part 30 with a predetermined pattern; data detection means 12 for detecting measurement data such as position data and drive power data of the drive part 30 by drive for diagnosis; evaluation calculation means 13 for calculating evaluation data such as backlash, position deviation, amplitude of the drive power and speed deviation from the measurement data; storage means 20 for storing the measurement data and the evaluation data in association with an execution date of the drive for diagnosis; comparison means 14 for comparing the evaluation data calculated by the evaluation calculation means 13 with the evaluation data stored in the storage means 20; and warning means 15 for issuing a warning when the comparison means 14 detects a predetermined change in the evaluation data.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a machine diagnosis system and a diagnosis program for diagnosing an operation state of a drive unit in a machine having one or more drive units such as a machine tool.

  2. Description of the Related Art Conventionally, as a diagnostic device for a machine having a drive unit such as a machine tool, a device that detects the presence or absence of abnormality such as vibration by installing a diagnostic sensor such as a vibration sensor in the drive unit is known. However, such a diagnostic apparatus increases the cost of the machine for installing the diagnostic sensor, and cannot detect an abnormality of the machine until a specific symptom such as vibration occurs.

  On the other hand, Patent Document 1 uses a drive power value detection means normally provided in a machine having a drive unit, and stores a normal drive power value of an actuator measured in advance in a storage means for detection. A failure diagnosing device is disclosed that compares the measured drive power value with a normal drive power value and determines that there is a failure in the operating system when the difference is greater than or equal to a threshold value. The failure diagnosis device compares the detected drive power value with the stored normal drive power value, and determines that the failure is a serious failure when the difference is greater than or equal to a certain threshold, and the difference is greater than or equal to a relatively small threshold. In some cases, it is judged as a minor failure.

JP 2000-250625 A

  The failure diagnosis device described in Patent Document 1 compares the detected drive power value with the stored normal drive power value, and determines that the operating system has a failure when the difference is equal to or greater than a threshold value. Thus, although not only a major failure but a minor failure can be determined based on different threshold values, there is a problem that a sign of a failure that occurs when the threshold value is less than the threshold cannot be detected in advance.

  Accordingly, the present invention provides a machine diagnosis that can diagnose an operation state of a drive unit and detect an abnormality of the drive unit and a sign of the abnormality in advance in a machine having one or more drive units such as a machine tool. A system and a diagnostic program are provided.

  In order to solve the above-described problems, the present invention provides a machine having one or two or more drive units, the drive unit having a position detector or / and a driving force detector. Diagnostic means for performing diagnostic driving driven by the control unit, data detecting means for detecting measurement data including position data or / and driving force data of the driving unit in the diagnostic driving, backlash, position deviation from the measurement data Evaluation evaluation means for calculating evaluation data including one or more evaluation data among the amplitude and speed deviation of the driving force, and the measurement data and the evaluation data as the execution time or / and the execution date and time of the diagnostic drive A storage means for storing in association; a comparison means for comparing the evaluation data calculated by the evaluation calculation means with the evaluation data stored in the storage means; and the comparison means, When detecting a predetermined change in the valence data, there is provided a warning means for issuing a warning indicates the type of the evaluation data and the driver applicable, a mechanical diagnostic system having a.

  Further, in the machine diagnosis system of the present invention, the evaluation calculation means includes means for frequency analysis of the driving force, and the comparison means compares the amplitude of the driving force in the entire frequency region or a part of the frequency region. Is provided.

  In the machine diagnosis system according to the present invention, the warning means issues a warning when any one of the evaluation data exceeds a preset value.

  Further, in the machine diagnosis system according to the present invention, the set value is set by adding a predetermined ratio to the value of the reference data, using the evaluation data calculated in the first or predetermined number of times of the diagnostic drive as reference data. It is what is done.

  Further, in the machine diagnosis system according to the present invention, the comparison unit includes a unit for obtaining a change rate of the evaluation data with respect to the number of times of the diagnostic drive or a lapse of time, and the warning unit includes a change rate of the predetermined rate. A warning is issued when the rate is exceeded.

  Further, in the machine diagnosis system according to the present invention, the comparison means includes means for obtaining a rate of change of the evaluation data with respect to the number of times of the diagnostic drive or a lapse of time, and the warning means is based on the rate of change. Means for predicting a time when the value of the evaluation data exceeds the set value is provided.

  Further, in the machine diagnosis system according to the present invention, the comparison means includes means for obtaining a change rate of the change in the evaluation data with respect to the number of times of the diagnostic drive or a lapse of time, and the warning means has a predetermined change rate. A warning is issued when the rate of change is exceeded.

  The present invention also provides a machine diagnosis program for causing a computer to function as the machine diagnosis system according to any one of the above.

  The machine diagnosis system according to the present invention has one or more drive units, and the drive unit is driven by a predetermined pattern in a machine provided with a position detector and / or a drive force detector. Diagnostic means for performing diagnostic driving, data detecting means for detecting measurement data including position data or / and driving force data of the driving unit in the diagnostic driving, backlash, position deviation, driving force from the measurement data Evaluation calculation means for calculating evaluation data including one or two or more evaluation data of amplitude and speed deviation, and storing the measurement data and the evaluation data in association with the execution time or / and the execution date and time of the diagnostic drive Storage means for comparing the evaluation data calculated by the evaluation calculation means with the evaluation data stored in the storage means, and the comparison means comprises the evaluation data And a warning means for issuing a warning indicating the type of the evaluation data when the predetermined change is detected, so that the drive unit is driven in a predetermined pattern, and the backlash Evaluation data such as position deviation, driving force amplitude, speed deviation, etc. can be calculated and stored in the storage means in association with the drive times / dates. Therefore, there is an effect that the calculated evaluation data and the evaluation data stored in the storage unit are compared to detect a predetermined change in the evaluation data, so that the abnormality of the drive unit and the sign of the abnormality can be detected in advance.

  The machine diagnosis system of the present invention calculates evaluation data from measurement data measured by a position detector, a driving force detector, etc. provided in a machine having a drive unit, and detects a predetermined change in the evaluation data. The operation status of the drive unit can be diagnosed at low cost, and the abnormality of the drive unit and the sign of abnormality can be detected in advance before the drive unit failure occurs. There is.

  Further, in the machine diagnosis system of the present invention, the evaluation calculation means includes means for frequency analysis of the driving force, and the comparison means compares the amplitude of the driving force in the entire frequency region or a part of the frequency region. By providing the above, there is an effect that it is possible to detect in advance the abnormality of the driving unit and a sign of abnormality from the change in the amplitude of the driving force in the entire frequency region or a part of the frequency region.

  In the machine diagnosis system according to the present invention, when the warning means exceeds a set value by issuing a warning when any one of the evaluation data exceeds a preset set value. In this case, it is possible to warn of an abnormality of the drive unit if there is an abnormality in the drive unit.

  Further, in the machine diagnosis system according to the present invention, the set value is set by adding a predetermined ratio to the value of the reference data, using the evaluation data calculated in the first or predetermined number of times of the diagnostic drive as reference data. As a result, the setting value can be automatically set for each machine.

  Further, in the machine diagnosis system according to the present invention, the comparison unit includes a unit for obtaining a change rate of the evaluation data with respect to the number of times of the diagnostic drive or a lapse of time, and the warning unit includes a change rate of the predetermined rate. By issuing a warning when the rate is exceeded, there is an effect that a sign of abnormality of the drive unit can be notified in advance before an abnormality occurs in the drive unit.

  Further, in the machine diagnosis system according to the present invention, the comparison means includes means for obtaining a rate of change of the evaluation data with respect to the number of times of the diagnostic drive or a lapse of time, and the warning means is based on the rate of change. By providing means for predicting the time when the value of the evaluation data exceeds the set value, it is possible to predict the time when an abnormality occurs in the drive unit, for example, it is possible to predict the replacement time of parts, etc. .

  Further, in the machine diagnosis system according to the present invention, the comparison means includes means for obtaining a change rate of the change in the evaluation data with respect to the number of times of the diagnostic drive or a lapse of time, and the warning means has a predetermined change rate. By issuing a warning when the rate of change exceeds this, it is possible to detect a sign of a change in evaluation data, and to detect and notify a sign of an abnormality in the drive unit at an early stage.

  In addition, the machine diagnosis program of the present invention causes the computer to function as the machine diagnosis system according to any one of the above, thereby driving the drive unit in a predetermined pattern to generate backlash, position deviation, Evaluation data such as the amplitude and speed deviation of the driving force can be calculated and stored in the storage means in association with the execution times / dates and times of the driving. Therefore, there is an effect that the calculated evaluation data and the evaluation data stored in the storage unit are compared to detect a predetermined change in the evaluation data, so that the abnormality of the drive unit and the sign of the abnormality can be detected in advance.

The block diagram which shows one Example of the diagnostic system of the machine which concerns on this invention. The flowchart which shows one Example of the diagnostic system of the machine which concerns on this invention. The flowchart which shows the log | history analysis of the diagnostic system of the machine which concerns on this invention. The block diagram which shows the other Example of the diagnostic system of the machine which concerns on this invention.

Embodiments of the present invention will be described based on examples shown in the drawings.
The machine diagnosis system 1 according to the present invention includes one or more drive units 30, and the drive unit 30 includes a position detector 31 and / or a drive force detector 32. Diagnosing means 11 for performing diagnostic driving for driving the sensor in a predetermined pattern, data detecting means 12 for detecting measurement data including position data or / and driving force data of the driving unit 30 in the diagnostic driving, and the measurement Evaluation calculation means 13 for calculating evaluation data including one or more evaluation data among backlash, position deviation, driving force amplitude, and speed deviation from the data; and the measurement data and the evaluation data are used for the diagnostic drive. Storage means 20 for storing in association with the implementation time or / and implementation date, the evaluation data calculated by the evaluation calculation means 13 and the evaluation data stored in the storage means 20 Comparing means 14, and when the comparing means 14 detects a predetermined change in the evaluation data, the corresponding drive unit 30 and warning means 15 for issuing a warning indicating the type of the evaluation data, Have.

FIG. 1 is a block diagram showing an embodiment of a machine diagnosis system according to the present invention.
In the embodiment shown in FIG. 1, the machine 3 is a machine tool such as a machining center having an X-axis drive unit 30x, a Y-axis drive unit 30y, a Z-axis drive unit 30z, and a main-axis drive unit 30s. Each drive part 30x, 30y, 30z, 30s of the machine tool 3 is driven by an electric motor. The X-axis drive unit 30x, the Y-axis drive unit 30y, and the Z-axis drive unit 30z include position detectors 31x, 31y, and 31z such as linear scales that detect the positions of the respective drive units, and drive currents of the respective drive units. Driving force detectors 32x, 32y, and 32z such as ammeters are detected. The spindle drive unit 30s is provided with a position detector 31s that detects a pulse signal corresponding to the rotation of a rotary encoder or the like, and a driving force detector 32s such as an ammeter that detects a drive current.

The machine tool 3 gives instructions such as machining conditions, tool change, coordinate setting, and the like to the control device 4 that numerically controls the drive of the X-axis drive unit 30x, the Y-axis drive unit 30y, the Z-axis drive unit 30z, and the spindle drive unit 30s An operation panel 5 for inputting and a monitor 6 for displaying processing information and position information are provided. The machine tool 3 may be provided with a vibration sensor that detects vibration of the drive unit 30. The driving force detector 32 may be any detector that can detect the driving force of the driving unit 30. When the driving unit 30 is driven by a hydraulic cylinder, a pressure sensor is used. The machine tool 3 is not limited to the three-axis machine of the present embodiment, and the present invention can be applied to various machine tools such as a five-axis machine and a lathe. Further, the present invention is not limited to the machine tool 3 and can be applied to various machines having a drive unit such as a transport device.
[Diagnostic system configuration]

  In the embodiment shown in FIG. 1, the diagnostic system 1 is provided in the control device 4 of the machine tool 3. The diagnostic unit 11 performs diagnostic driving for driving the driving unit 30 in a predetermined pattern in a state where no load is applied to the driving unit 30 of the machine tool 3. As the predetermined pattern, for example, the diagnosis unit 11 reciprocates each of the X-axis drive unit 30x, the Y-axis drive unit 30y, and the Z-axis drive unit 30z. Further, the diagnosis unit 11 drives the spindle drive unit 30s to rotate. The diagnosis unit 11 may drive each driving unit individually or may be driven by reciprocating each driving unit.

  It is preferable that the diagnostic unit 11 periodically performs the diagnostic drive of the drive unit 30 when the machine tool 3 is not in operation, and automatically activates the diagnostic drive of the drive unit 30 when the machine tool 3 is started. More preferably. When the diagnosis unit 11 automatically performs the diagnosis drive of the drive unit 30, the diagnosis unit 11 displays a confirmation screen “Do you want to execute the diagnosis drive?” On the monitor 6, and allows the operator to operate from the operation panel 5. You may be made to input confirmation. In addition, the diagnosis unit 11 can also perform a drive for diagnosis of the drive unit 30 by an operation from the operation panel 5.

  As the measurement data, the data detection unit 12 detects the position data of the moving body in the diagnostic drive by the position detector 31, and detects the drive current data of the electric motor in the diagnostic drive by the driving force detector 32. In the embodiment, the detected measurement data is stored in the storage unit 20 in association with the execution date and time of the diagnostic drive. The measurement data in each diagnostic drive is detected as time series data and stored in the storage means 20. The data detection means 12 may detect other measurement data such as vibration data when the machine tool 3 includes another sensor such as a vibration sensor in the drive unit 30.

  In this embodiment, the evaluation calculation means 13 calculates backlash, drive current amplitude and speed deviation from the measurement data as evaluation data. The evaluation calculation unit 13 calculates the backlash of the drive unit 30 from the position data detected by the position detector 31 and the control data for controlling the drive unit 30. When the drive unit 30 is driven by a drive device without backlash, such as a linear motor, the evaluation calculation unit 13 may calculate a position deviation as evaluation data. The evaluation calculation unit 13 calculates the speed of the drive unit 30 from the time-series position data detected by the position detector 31 and calculates a speed deviation with respect to the speed based on the control data of the drive unit 30.

  The evaluation calculation means 13 calculates the amplitude of the drive current from the time-series drive current detected by the drive force detector 32. In this embodiment, the evaluation calculation means 13 includes means for performing frequency analysis by performing Fourier transform on the amplitude of the drive current in the time axis direction. The evaluation calculation means 13 may cut a high frequency component by providing a low pass filter in the frequency analysis of the drive current. The calculated evaluation data is stored in the storage unit 20 in association with the execution date and time of the diagnostic drive. The evaluation data may be stored in the storage unit 20 in association with the execution time of the diagnostic drive, or may be stored in the storage unit 20 in association with the operating time of the machine tool 3.

  The comparison unit 14 compares the evaluation data calculated by the evaluation calculation unit 13 with the evaluation data stored in the storage unit 20. When the comparison unit 14 detects a predetermined change in the evaluation data, the warning unit 15 issues a warning to the monitor 6 indicating the corresponding drive unit 30 and the type of the evaluation data. For example, the comparison unit 14 compares the evaluation data calculated by the evaluation calculation unit 13 with the evaluation data stored in the storage unit 20, and the warning unit 15 issues a warning when a change of a predetermined ratio or more is detected. The comparison unit 14 may analyze the history of the evaluation data calculated by the evaluation calculation unit 13 and the evaluation data stored in the storage unit 20, and may issue a warning when the change rate exceeds a predetermined change rate. .

  In the present embodiment, the warning means 15 issues a warning when any one of the evaluation data exceeds a preset set value. This set value is preferably set by using the evaluation data calculated in the first diagnostic drive or the first diagnostic drive from the first time as reference data, and adding a predetermined ratio to the value of the reference data. The set value may be a set value set by another machine for the same type of machine, or the set value and a set value set from the diagnostic drive for each machine may be used in combination. Good.

  The comparison unit 14 includes a unit that compares the amplitude of the drive current in the frequency domain, and compares the level and the set value for the amplitude of the drive current in the entire band. The warning means 15 issues a warning when the level exceeds a set value. The comparison unit 14 compares the backlash value and the speed deviation with the set values, and the warning unit 15 issues a warning when the set values are exceeded. The predetermined ratio to be added to the reference data is preferably set for each evaluation data according to the characteristics of the evaluation data.

  Moreover, the comparison means 14 is provided with a means for obtaining a rate of change of evaluation data with respect to time passage of the diagnostic drive. The comparison means 14 obtains the rate of change of the evaluation data with respect to time by the least square method for the evaluation data of the most recent N times (N ≧ 2) diagnostic drive. The warning means 15 issues a warning to the monitor 6 when the change rate exceeds a predetermined change rate. The warning unit 15 may include a unit that predicts a time when the value of the evaluation data exceeds the set value based on the change rate. When the time when the value of the evaluation data is predicted to exceed the set value is shorter than the service life of the drive unit 30, it is preferable that the warning unit 15 issues a warning notifying the abnormality.

  When the evaluation data is stored in the storage unit 20 in association with the execution time of the diagnostic drive, the comparison unit 14 obtains the rate of change of the evaluation data with respect to the number of times of the diagnostic drive. When stored in the storage means 20 in association with the operating time, the rate of change of the evaluation data with respect to the lapse of the operating time of the machine tool 3 is obtained.

Further, the comparison unit 14 may include a unit that obtains a change rate of the change in the evaluation data with respect to the elapsed time of the diagnostic drive. At this time, the comparison means 14 obtains the rate of change of the evaluation data by second-order differentiation of the evaluation data with respect to time. The warning means 15 issues a warning to the monitor 6 when the latest change rate exceeds a predetermined change rate.
[Operation of diagnostic system]

  Next, the operation of the machine diagnosis system according to the present invention will be described. FIG. 2 is a flowchart showing an embodiment of the machine diagnosis system according to the present invention, and FIG. 3 is a flowchart showing history analysis of the machine diagnosis system according to the present invention.

  The diagnostic means 11 gives an initial value “0” to the number of diagnoses n when the machine tool 3 is first activated (step S11). The diagnosis unit 11 may have a function of resetting the diagnosis count n from the operation panel 5 to the initial value “0”, and can be reset when a part of the drive unit 30 is replaced. In addition, when the machine tool 3 is installed in the factory, the diagnosis number 1 is reset to the initial value “0”, so that the diagnosis system 1 eliminates fluctuation due to the transfer of the machine tool 3 and diagnoses the drive unit 30. It can be performed. In addition, it is preferable that the diagnosis means 11 manages the frequency | count n of diagnosis separately in the some drive part 30. FIG.

  The diagnosis unit 11 performs a diagnosis drive for driving the drive unit 30 in a predetermined pattern without applying a load to the drive unit 30 of the machine tool 3 (step S12). For example, the diagnosis unit 11 automatically performs a diagnostic drive when the machine tool 3 is started, and reciprocates the X-axis drive unit 30x, the Y-axis drive unit 30y, and the Z-axis drive unit 30z a plurality of times in conjunction with each other. Further, the diagnosis unit 11 drives the spindle drive unit 30s to rotate. The diagnostic drive of the main shaft drive unit 30s is preferably performed by rotating and stopping a plurality of times.

  When the diagnostic drive of the drive unit 30 is completed, the diagnostic unit 11 adds “1” to the number of diagnoses n (step S13).

  The data detection means 12 detects position data of each moving body in the diagnostic drive as measurement data by the position detectors 31x, 31y, and 31z, and the drive current data of each electric motor in the diagnostic drive as the driving force detector 32x. , 32y, 32z. Further, as the measurement data of the spindle drive unit 30s, the data detection means 12 detects a pulse signal corresponding to the rotation of the spindle in the diagnostic drive by the position detector 31s, and drives the drive current data of the electric motor in the diagnostic drive. It is detected by a force detector 32s. Further, the data detection unit 12 stores the detected measurement data in the storage unit 20 for each of the drive units 30x, 30y, 30z, and 30s in association with the execution date and time of the diagnostic drive (step S14). At this time, the data detection means 12 includes position data detected by the position detectors 31x, 31y, 31z, and 31s, and position control data for controlling the positions of the driving units 30x, 30y, 30z, and 30s. The data is stored in the storage unit 20 in association with time series data.

  The evaluation calculation means 13 uses the position data of the drive units 30x, 30y, and 30z detected by the position detectors 31x, 31y, and 31z and the position control data that controls the drive units 30x, 30y, and 30z, respectively. The backlash values of the drive units 30x, 30y, and 30z are calculated (step S15). Further, the evaluation calculation means 13 determines the speed of the spindle drive unit 30s from the pulse signal data corresponding to the rotation of the spindle drive unit 30s detected by the position detector 31s and the control data such as the speed for controlling the spindle drive unit 30s. Calculate the (rotation) deviation. Further, the evaluation calculation means 13 is configured so that each of the driving units is based on the time series driving currents of the driving units 30x, 30y, 30z, and 30s detected by the driving force detectors 32x, 32y, 32z, and 32s in parallel. The amplitude of the drive current at 30x, 30y, 30z, and 30s is subjected to frequency analysis by performing Fourier transform in the time axis direction (step S16). Moreover, the evaluation calculation means 13 may calculate a speed deviation etc. as evaluation data.

  Next, the evaluation calculation means 13 determines whether or not the number of diagnoses n is greater than “1” (step S17). When the number of diagnoses n is “1”, the respective drive units 30x, 30y, 30z, and 30s. Evaluation data such as a backlash value or a speed deviation and an amplitude of the drive current subjected to frequency analysis are stored in the storage unit 20 as initial values (step S18). In this embodiment, the evaluation calculation unit 13 stores the amplitude level of the drive current in the storage unit 20 as an initial value. Moreover, the evaluation calculation means 13 preserve | saves each value in a memory | storage means 20 as an initial value about a speed deviation and a position deviation.

  When the evaluation calculation means 13 saves the evaluation data in the storage means 20 as an initial value, the warning means 15 adds a predetermined ratio to the initial value and sets it as a warning value for each drive unit 30x, 30y, 30z, 30s. Then, the warning value is stored in the storage means 20 (step S19). The warning means 15 determines a predetermined ratio to be added to the initial value for each evaluation data according to the characteristics of the evaluation data such as the backlash value or speed deviation, the amplitude of the drive current subjected to frequency analysis, and sets the warning value. The warning value is set to a value of 150% or 200% of the initial value, for example.

  When the warning value is set, the diagnostic system 1 returns to step S12 and waits for the next diagnostic drive. The diagnostic unit 11 automatically performs the diagnostic drive of the drive unit 30 by an operation from the operation panel 5 or when the machine tool 3 is activated.

  If it is determined in step S17 that the number of diagnoses n is greater than “1”, the evaluation calculation means 13 determines the backlash value or speed deviation in each of the drive units 30x, 30y, 30z, and 30s, and the frequency-analyzed drive. Evaluation data such as current amplitude is stored in the storage means 20 as a diagnostic value (step S20). In this embodiment, the evaluation calculation unit 13 stores the amplitude level of the drive current in the storage unit 20 as a diagnostic value. Moreover, the evaluation calculation means 13 preserve | saves each value for a speed deviation and a position deviation in the memory | storage means 20 as a diagnostic value.

  The comparison means 14 compares the diagnostic value with the warning value for each evaluation data such as backlash value or speed deviation, frequency-analyzed drive current amplitude in each of the drive units 30x, 30y, 30z, and 30s (step) S21). When the comparison unit 14 determines that all the diagnostic values are equal to or less than the warning value, the diagnostic system 1 returns to step S12 and waits for the next diagnostic drive.

  In step S21, when the comparison unit 14 determines that any one of the diagnostic values exceeds a preset setting value, the warning unit 15 sends the corresponding drive unit 30 and the evaluation data. A warning is issued to the monitor 6 indicating the type (step S22).

  The machine diagnosis system of the present invention calculates evaluation data from measurement data measured by a position detector 31 and a driving force detector 32 provided in the machine tool 3, and detects a predetermined change in the evaluation data. Since a warning can be issued, the operating state of each of the drive units 30x, 30y, 30z, and 30s can be diagnosed at a low cost by incorporating a program into the control device 4 of the machine tool 3. In addition, the machine diagnosis system according to the present embodiment automatically sets the warning value (set value) for each machine because the evaluation data calculated in the first diagnostic drive is set as an initial value (reference data). Therefore, diagnosis suitable for each machine can be performed easily and at low cost.

  Next, the flow of history analysis of each evaluation data will be described based on FIG.

  The comparison unit 14 determines whether or not the number of diagnoses n is larger than a predetermined number N (N ≧ 2) set in advance (step S101). When the number of diagnoses n is equal to or less than the predetermined number N, the diagnosis system 1 executes the diagnosis procedure illustrated in FIG. 2 until the number of diagnoses n exceeds the predetermined number N. The predetermined number N is preferably set as appropriate according to the time interval for performing the diagnostic drive of the drive unit 30 by the diagnostic unit 11, for example, “N = 10”. The predetermined number N is preferably set to a large number when the time interval for performing the diagnostic drive is short, and set to a small number when the time interval for performing the diagnostic drive is long.

  When the number of diagnoses n exceeds the predetermined number N, the comparison unit 14 determines the backlash value or the speed deviation and the amplitude of the drive current subjected to frequency analysis in each of the drive units 30x, 30y, 30z, and 30s. The change rate of the diagnostic value is obtained for each evaluation data (step S102). Specifically, the comparison unit 14 obtains the rate of change of the diagnostic value with respect to time by the least square method for the diagnostic value of the N most recent diagnostic drives.

  The comparison means 14 is preset with the rate of change of the diagnostic value for each evaluation data such as backlash value or speed deviation and frequency-analyzed drive current amplitude in each of the drive units 30x, 30y, 30z, and 30s. The predetermined value is compared (step S103). When the comparison unit 14 determines that any one of the change rates of the diagnostic value exceeds the preset set value, the warning unit 15 sends the corresponding drive unit 30 and the evaluation data. A warning is issued to the monitor 6 indicating the type (step S104). At this time, the warning means 15 may predict the time when the value of the evaluation data exceeds the set value based on the rate of change of the diagnostic value, and display the predicted time on the monitor 6.

  In step S103, when the comparison unit 14 determines that the rate of change of all the diagnostic values is equal to or less than a preset set value, the comparison unit 14 determines that the drive units 30x, 30y, 30z, and 30s Then, the change rate of the change in the diagnostic value is obtained for each evaluation data such as the backlash value or the speed deviation and the amplitude of the drive current subjected to the frequency analysis (step S105). Specifically, the comparison means 14 obtains the rate of change in the change in the diagnostic value by second-order differentiation of the diagnostic value with respect to the diagnostic value of the N most recent diagnostic drives.

  The comparison means 14 is preset with the rate of change of the diagnostic value for each evaluation data such as backlash value or speed deviation and frequency-analyzed drive current amplitude in each of the drive units 30x, 30y, 30z, and 30s. The predetermined value is compared (step S106). When the comparison unit 14 determines that any one of the change rates of the change in the diagnostic value exceeds the preset setting value, the warning unit 15 A warning is issued to the monitor 6 indicating the type of evaluation data (step S107).

  In step S106, when the comparison unit 14 determines that the change rate of all the diagnostic value changes is equal to or less than a preset set value, the diagnostic system 1 continues diagnosis of the machine tool 3 (step S106). S108).

  In the machine diagnosis system according to the present invention, the rate of change of evaluation data with respect to the time lapse of diagnostic drive or the rate of change of evaluation data with respect to the time lapse of diagnostic drive exceeds a predetermined rate of change (set value). Since sometimes a warning can be issued, a sign of abnormality of the drive unit 30 can be notified in advance before the diagnostic value exceeds the warning value. Further, in the machine diagnosis system of the present embodiment, the warning means 15 can predict the time when the diagnosis value exceeds the warning value based on the rate of change of the diagnosis value, and for example, can predict the replacement time of the parts. It becomes possible.

  The diagnosis system 1 does not have to perform diagnosis of all the drive units 30 in the machine 3 having two or more drive units 30 at the same time, and appropriately performs the diagnostic drive according to the durability of each drive unit 30. Should be implemented.

FIG. 4 is a block diagram showing another embodiment of the machine diagnostic system according to the present invention.
In the embodiment shown in FIG. 4, the diagnostic system 1 is provided in a host computer 10 connected to one or more machine tools 3 via a network 2. The host computer 10 is a computer that manages a numerical control program for numerically controlling the machine tool 3 and includes a calculation unit, a storage unit, an input unit, and a display unit. Although not shown, the machine tool 3 includes a control device 4 that numerically controls the drive of the drive units 30x, 30y, 30z, and 30s, and an operation panel 5 that inputs instructions such as machining conditions, tool change, and coordinate settings. And a monitor 6 for displaying processing information and position information.

  The diagnosis unit 11 periodically drives each drive unit 30 of the machine tool 3 for diagnosis via the control device 4 of the machine tool 3 connected by the network 2. In addition, the diagnosis unit 11 can specify the number of the machine tool 3 to be diagnosed from the input unit of the host computer 10 and instruct execution of the diagnosis drive. In addition, each time the diagnostic unit 11 transmits a numerical control program to the machine tool 3, the diagnostic unit 11 may automatically perform diagnostic driving before starting machining by the program.

  The data detection means 12 detects position data detected by the position detector 31 and the driving force detector 32 or measurement data such as pulse signal data corresponding to rotation and driving current via the control device 4 of the machine tool 3. To do. Other configurations are the same as the configuration of the machine diagnosis system described in the first embodiment.

  The machine diagnosis system of the present embodiment can centrally manage the operating states of all machine tools 3 by a host computer 10 connected to one or more machine tools 3 via a network 2.

DESCRIPTION OF SYMBOLS 1 Diagnosis system 2 Network 3 Machine 4 Control apparatus 5 Operation panel 6 Monitor 10 Host computer 11 Diagnosis means 12 Data detection means 13 Evaluation calculation means 14 Comparison means 15 Warning means 20 Storage means 30 Drive part 31 Position detector 32 Driving force detector

Claims (8)

In a machine having one or two or more driving units, the driving unit having a position detector or / and a driving force detector,
Diagnostic means for performing diagnostic driving for driving the driving unit in a predetermined pattern;
Data detection means for detecting measurement data including position data or / and driving force data of the drive unit in the diagnostic drive;
Evaluation calculation means for calculating evaluation data including one or more evaluation data among backlash, position deviation, driving force amplitude, speed deviation from the measurement data;
Storage means for storing the measurement data and the evaluation data in association with the execution time or / and the execution date and time of the diagnostic drive;
Comparison means for comparing the evaluation data calculated by the evaluation calculation means with the evaluation data stored in the storage means;
When the comparison means detects a predetermined change in the evaluation data, a warning means for issuing a warning indicating the type of the corresponding drive unit and the evaluation data;
Machine diagnostic system.   The machine diagnosis according to claim 1, wherein the evaluation calculation unit includes a unit that performs frequency analysis of the driving force, and the comparison unit includes a unit that compares the amplitude of the driving force in the entire frequency region or a partial frequency region. system.   3. The machine diagnosis system according to claim 1, wherein the warning unit issues a warning when any one of the evaluation data exceeds a preset value. 4.   The machine diagnosis according to claim 3, wherein the set value is set by adding a predetermined ratio to a value of the reference data using the evaluation data calculated in the first or predetermined number of times of the diagnostic drive as reference data. system.   The comparison means includes means for obtaining a rate of change of the evaluation data with respect to the number of times of the diagnostic drive or the passage of time, and the warning means issues a warning when the rate of change exceeds a predetermined rate of change. The machine diagnostic system according to any one of claims 1 to 4.   The comparison means includes means for obtaining a rate of change of the evaluation data with respect to the number of times of the diagnostic drive or a lapse of time, and the warning means is a timing when the value of the evaluation data exceeds the set value based on the rate of change. The machine diagnosis system according to any one of claims 3 to 5, further comprising a unit for predicting the above.   The comparison means includes means for obtaining a change rate of the change in the evaluation data with respect to the number of times of the diagnostic drive or a lapse of time, and the warning means issues a warning when the change rate exceeds a predetermined change rate. The machine diagnostic system according to claim 5 or 6.   A machine diagnosis program for causing a computer to function as the machine diagnosis system according to any one of claims 1 to 7.

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