Device for diagnosing anomalies and procedure for diagnosing anomalies

Abstract

An anomaly diagnostic device (1A) comprises an instruction generation unit (11) that generates an instruction value to specify the operation of a motor (2) or a drive machine (3), a drive control unit (12A) that performs feedback control on the motor based on a control gain (D1) so that the operation of the motor or drive machine follows the instruction value, a data transmission unit (13) that transmits selected time series data (D5) by selecting data from time series data (D2) based on the result of a comparison between a control bandwidth determined from the control gain and a threshold determined by the drive machine, which indicates the state of the motor or drive machine, and an anomaly detection unit (14) that determines an anomalous state of the motor or drive machine based on the selected time series data.

Description

Area

[0001] The present disclosure relates to an abnormality diagnosis apparatus and an abnormality diagnosis method for diagnosing abnormalities of an engine or a prime mover. background

[0002] In manufacturing facilities such as factories, the failure of a prime mover that uses a motor as a power source leads to a reduction in the field rate. To prevent this reduction in the field rate, a maintenance method known as TBM (Time Based Maintenance) has been used in factories. In this method, the prime mover is regularly serviced to replace parts that have been used for a certain period of time. Recently, a maintenance method known as CMB (Condition Based Maintenance) has been increasingly used in factories instead of TBM. In this method, the maintenance decision as to whether or not parts need to be replaced is based on data collected by the prime mover (internal data of the prime mover or external sensor data from an accelerometer, etc.).For example, CBM is a method that uses statistical processing, machine learning, or artificial intelligence (AI) calculations to determine whether the drive machine is running normally or abnormally based on the collected data.

[0003] A motor control system described in Patent Document 1 determines a data anomaly based on a comparison between a data anomaly determination threshold and the Mahalanobis distance calculated based on the time series data acquired at the time of motor driving. List of citationsPatent literature

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2019-024305 Short descriptionTechnical problem

[0005] However, in the technique of Patent Document 1, the data is analyzed without selecting the collected data, so that a huge amount of data, including redundant data with little relevance to anomalies, is analyzed, which is a problem because the accuracy of anomaly diagnosis is reduced.

[0006] The present disclosure has been made in view of the above, and an object is to provide an abnormality diagnosis apparatus capable of performing highly accurate abnormality diagnosis. Solution to the problem

[0007] To solve the above problems and achieve the object, an abnormality diagnosis device according to the present disclosure includes: a command generation unit for generating a command value specifying the operation of a motor or a prime mover driven by the motor; and a drive control unit for performing feedback control on the motor based on a control gain so that the operation of the motor or prime mover follows the command value. Furthermore, the abnormality diagnosis device includes a data switching unit.A data switching unit for switching selected time series data by selecting data from time series data indicating a state of the engine or the prime mover based on the result of a comparison between a control bandwidth determined from the control gain and a threshold value determined from the prime mover; and an abnormality determination unit for determining an abnormal state of the engine or the prime mover based on the selected time series data. Advantageous effects of the invention

[0008] The abnormality diagnosis apparatus according to the present disclosure has the effect that highly accurate abnormality diagnosis can be performed. Short description of the characters Fig. 1 is a diagram showing an example of the configuration of an abnormality diagnosis apparatus according to a first embodiment. Fig. 2 is a diagram showing an example of the configuration of a drive control unit included in an abnormality diagnosis apparatus according to the first embodiment. Fig. 3 is a flowchart illustrating the flow of a procedure performed by a data relay unit included in an abnormality diagnosis apparatus according to the first embodiment. Fig. 4 is a diagram for explaining a method of calculating a control bandwidth from a control gain by an abnormality diagnosis apparatus according to the first embodiment. Fig. 5 is a diagram showing another example of the configuration of a drive control unit included in an abnormality diagnosis apparatus according to the first embodiment. Fig. 6 is a diagram showing an example of the configuration of an abnormality diagnosis apparatus according to a second embodiment. Fig. 7 is a diagram showing an example of a target speed used by an abnormality diagnosis apparatus according to the second embodiment. Fig. 8 is a flowchart illustrating the flow of a procedure performed by a data relay unit included in an abnormality diagnosis apparatus according to the second embodiment. Fig. 9 is a diagram showing an example of the configuration of an abnormality diagnosis apparatus according to a third embodiment. Fig. 10 is a diagram showing an example of the configuration of gears included in a prime mover on which abnormality diagnosis is performed by an abnormality diagnosis apparatus according to the third embodiment. Fig. 11 is a flowchart illustrating the flow of a procedure performed by a data relay unit included in an abnormality diagnosis apparatus according to the third embodiment. Fig. 12 is a diagram showing an example of the configuration of a rolling bearing on which an abnormality diagnosis is performed by an abnormality diagnosis apparatus according to the third embodiment. Fig. 13 shows a diagram explaining the contact angle of a Fig. 12 shown rolling bearing. Fig. 14 is a diagram showing an example of the configuration of an abnormality diagnosis apparatus according to a fourth embodiment. Fig. 15 is a flowchart illustrating the flow of a procedure performed by a data relay unit included in an abnormality diagnosis apparatus according to the fourth embodiment. Fig. 16 is a diagram showing an example of a hardware configuration for implementing the abnormality diagnosis apparatus according to the first embodiment. Description of embodiments

[0009] Hereinafter, an abnormality diagnosis apparatus and an abnormality diagnosis method according to embodiments of the present disclosure will be described in detail with reference to the figures. First embodiment

[0010] Fig. 1 is a diagram illustrating an example of the configuration of an abnormality diagnosis device according to a first embodiment. The abnormality diagnosis device 1A is a device that diagnoses abnormalities of an engine 2 or a prime mover 3. The prime mover 3 is connected to the engine 2 and operates using the engine 2 as a power source. The engine 2 and the prime mover 3 are connected to a condition monitoring unit 4. The abnormality diagnosis device 1A is connected to the condition monitoring unit 4 and the engine 2.

[0011] The abnormality diagnosis device 1A includes a command generation unit 11, a drive control unit 12A, a data exchange unit 13, and an abnormality determination unit 14.

[0012] The command generation unit 11 generates a command value for causing the motor 2 and the prime mover 3 to perform a desired drive operation (a command value specifying an operation) and outputs the generated command value to the drive control unit 12A. The drive control unit 12A supplies a drive current based on a preset control gain D1 (such as a position control gain or speed control gain to be described later) to the motor 2 so that the operation of the motor 2 or the prime mover 3 follows the command value input from the command generation unit 11. The drive control unit 12A performs feedback control on the motor 2 based on the data acquired from the condition monitoring unit 4 and the command value input from the command generation unit 11. The drive control unit 12A outputs the control gain D1 to the data exchange unit 13.

[0013] The first embodiment describes, as an example, a case where the command generation unit 11 generates the command value of a position command (a position command P1 to be described later), and the drive control unit 12A causes an actual position (an actual position P11 to be described later) to follow the position command P1. However, the command value is not limited to the position command P1. Therefore, the command generation unit 11 may also generate the command value of a speed command, and the drive control unit 12A may cause an actual speed to follow the speed command, or other processing may be performed. The position command P1 is a command for the position (e.g., the rotation position or the movement position) of the motor 2 or a command for the drive position of the prime mover 3.The speed command is a command for the speed (e.g., the rotational speed or the travel speed) of the motor 2 or a command for the drive speed of the prime mover 3.

[0014] The following mainly describes a case where the position command P1 is a position command to the motor 2, but the position command P1 may be a position command to the prime mover 3. The following mainly describes the case where the actual position P11 is the position of the motor 2, but the actual position P11 may also be the position of the prime mover 3. The following mainly describes the case where the speed command is a speed command to the motor 2, but the speed command may be a speed command to the prime mover 3. The following mainly describes a case where the actual speed is the speed of the motor 2, but the actual speed may also be the speed of the prime mover 3.

[0015] Motor 2 operates according to the drive current. Motor 2 transmits a drive torque to drive machine 3 to operate it. Motor 2 can be a rotary motor or a linear motor that performs a translational movement.

[0016] At least one motor 2 is connected to the drive machine 3. The drive machine 3 comprises, for example, an XY table moving in an XY plane, a mechanical element such as a ball screw, a gear, or a belt, or a group of elements combining these.

[0017] The condition monitoring unit 4 observes the condition of the motor 2 and / or the prime mover 3 and obtains the monitoring results as time-series data D2. In the first embodiment, the condition monitoring unit 4 collects position data of the motor 2 and outputs the time-series data D2 of the position data to the drive control unit 12A. A specific example of the condition monitoring unit 4 is a encoder mounted on a servo motor. The condition monitoring unit 4 is not limited to an encoder. For example, if a linear scale capable of detecting the displacement of the prime mover 3 is used, the encoder also corresponds to the condition monitoring unit 4.

[0018] It should be noted that the condition monitoring unit 4 may output the collected time series data D2 to the data relay unit 13 without outputting the collected time series data D2 to the drive control unit 12A. Alternatively, the condition monitoring unit 4 may output part of the time series data D2 to the drive control unit 12A and output the remaining time series data D2 to the data relay unit 13. In this case, the condition monitoring unit 4 may output time series data D2 including time series data D2 to be output to the drive control unit 12A to the data relay unit 13, or it may output time series data D2 including time series data D2 to be output to the data relay unit 13 to the drive control unit 12A. That is, the condition monitoring unit 4 may output some or all of the collected time series data D2 to the drive control unit 12A and the data relay unit 13.

[0019] The data switching unit 13 receives the time series data D2 output from the condition monitoring unit 4 or the drive control unit 12A. Fig. 1 shows a case where the data switching unit 13 receives the time series data D2 from the drive control unit 12A.

[0020] The time series data D2 received by the data exchange unit 13 from the condition monitoring unit 4 or the drive control unit 12A is the time series data D2 acquired from the condition monitoring unit 4 or processed time series data obtained by arithmetic processing (processing) the time series data D2 acquired from the condition monitoring unit 4. Thus, in the first embodiment, the time series data D2 may include processed time series data. The arithmetic processing of the time series data D2 is performed by the condition monitoring unit 4 or the drive control unit 12A.

[0021] Note that the time series data D2 is not limited to the data acquired by the condition monitoring unit 4, but may also be data generated by the drive control unit 12A or the command generation unit 11. The time series data D2 includes data acquired by the condition monitoring unit 4 (first data) and / or data generated by the drive control unit 12A (second data) and / or data generated by the command generation unit 11 (third data).

[0022] The processed time series data is time series data obtained by performing the four basic arithmetic operations, a differentiation operation, an integration operation, filtering, or a combined processing on the time series data D2. For example, a position deviation, a disturbance torque estimate, which is an estimated value of a disturbance torque on the motor 2 or the prime mover 3, or the like correspond to the processed time series data. The position deviation is the difference between the position command P1 corresponding to the actual position P11 and the actual position P11, and is obtained by subtracting the actual position P11 from the position command P1.

[0023] The resonance frequency D3 (information about the resonance frequency) of the prime mover 3 is input to the data relay unit 13 in advance. The data relay unit 13 receives the resonance frequency D3 of the prime mover 3 from a device for measuring the resonance frequency D3 or the like. The resonance frequency D3 of the prime mover 3 is measured by subjecting the prime mover 3 to sine sweep vibration in advance or by conducting an impact test on the prime mover 3 in advance. The measured resonance frequency D3 is input to the abnormality diagnosis device 1A as input data of the data relay unit 13.

[0024] The data switching unit 13 calculates a threshold value determined by the drive machine 3 based on the resonance frequency D3. This threshold value is a threshold value that is compared with a control bandwidth (e.g., a speed control bandwidth).

[0025] Since the resonance frequency D3 depends on the prime mover 3, the threshold value calculated based on the resonance frequency D3 depends on the prime mover 3. That is, the threshold value is a value determined by the prime mover 3. The data switching unit 13 switches time series data to be output to the abnormality determination unit 14 (selected time series data D5) based on the acquired control gain D1, the acquired time series data D2, and the threshold value determined by the prime mover 3.

[0026] Specifically, the data switching unit 13 calculates the control bandwidth based on the control gain D1. If the control gain D1 is the speed control gain, the data switching unit 13 calculates the speed control bandwidth based on the speed control gain.

[0027] For example, the data switching unit 13 selects the actual position P11 as the type of selected time series data D5 when the speed control bandwidth is smaller than the threshold, and the actual current of the motor 2 as the type of selected time series data D5 when the speed control bandwidth is larger than the threshold. The actual position P11 is the actual position of the motor 2 or the prime mover 3. The selected time series data D5 is time series data selected and output by the data switching unit 13 from the time series data D2. The data switching unit 13 outputs the selected time series data D5 to the abnormality determination unit 14.

[0028] The anomaly determination unit 14 determines whether the engine 2 or the prime mover 3 to be evaluated is running normally or abnormally based on the selected time series data D5 output from the data relay unit 13. The anomaly determination unit 14 performs normal and abnormal determination, for example, through unsupervised learning. Unsupervised learning is a method in which only normal data (the time series data D2 when the determination judgment is normal) is used as training data, and the anomaly determination is performed on the selected time series data D5 after learning. Examples of unsupervised learning include cluster analysis and principal component analysis.

[0029] It is noted that the anomaly determination unit 14 may use supervised learning using the time series data D2 with correct labels attached to the training data, or reinforcement learning for learning actions to maximize a reward set according to the purpose, or other methods.

[0030] The abnormality determination unit 14 outputs the determination target, a determination item, and a determination result to an external device such as a display device 5. The determination target output by the abnormality determination unit 14 is the motor 2 or the prime mover 3. The determination item output by the abnormality determination unit 14 is the position deviation, the disturbance torque estimate, or the like. The determination result output by the abnormality determination unit 14 is an abnormality or normality. The display device 5 displays the determination target, the determination item, and the determination result.

[0031] Fig. Figure 2 is a diagram illustrating an example of the configuration of a drive control unit included in an abnormality diagnosis device according to the first embodiment. The drive control unit 12A includes a subtractor 21, a position control unit 121, a subtractor 22, a speed control unit 122, a subtractor 23, a current control unit 123, and a speed conversion unit 124.

[0032] The condition monitoring unit 4 acquires the actual position P11 and the actual current P10 in the form of time series data D2 and outputs the actual position P11 and the actual current P10 to the drive control unit 12A. The actual position P11 and the actual current P10 are also sent to the data exchange unit 13 via the drive control unit 12A. The actual position P11 is an actual position detected at the motor 2, and the actual current P10 is an actual current detected at the motor 2.

[0033] The subtractor 21 receives the position command P1 output from the command generation unit 11 and the actual position P11 output from the state monitoring unit 4. The actual position P11 is the actual position (e.g., the rotation position or travel position) of the motor 2 or the actual drive position of the prime mover 3. The subtractor 21 calculates a position deviation P2 by subtracting the actual position P11 from the position command P1 and outputs the calculated position deviation P2 to the position control unit 121.

[0034] The position control unit 121 calculates a speed command P3 based on the position deviation P2, for example, through proportional-integral-derivative (PID) control, and outputs the speed command P3. The speed command P3 is a speed command (e.g., rotation speed or movement speed) to the motor 2 or a speed command (e.g., drive speed) to the prime mover 3. The PID control includes the control gain D1. In the first embodiment, the control gain D1 of the position control unit 121 is referred to as the position control gain. The position control unit 121 outputs the speed command P3 to the subtractor 22.

[0035] The speed conversion unit 124 calculates the actual speed P8 by, for example, time-differentiating the actual position P11 output by the condition monitoring unit 4. The speed conversion unit 124 outputs the actual speed P8 to the subtractor 22. The actual speed P8 is the actual speed (e.g., rotational speed or movement speed) of the motor 2 or the actual drive speed of the prime mover 3.

[0036] The subtractor 22 receives the speed command P3 output from the position control unit 121 and the actual speed P8 output from the speed conversion unit 124. The subtractor 22 subtracts the actual speed P8 from the speed command P3 to calculate the speed deviation P4, which is the difference between the speed command P3 and the actual speed P8. The subtractor 22 outputs the calculated speed deviation P4 to the speed control unit 122.

[0037] The speed control unit 122 calculates a current command P5, for example, by PID control based on the speed deviation P4, and outputs the current command P5. The current command P5 is a current command for driving the motor 2. As described above, the PID control includes the control gain D1. In the first embodiment, the control gain D1 of the speed control unit 122 is referred to as the speed control gain P9. The speed control gain P9 is an example of the control gain D1 described above. The first embodiment mainly describes a case where the control gain D1 is the speed control gain P9. The speed control unit 122 outputs the current command P5 to the subtractor 23. The speed control unit 122 outputs the speed control gain P9 to the data exchange unit 13.

[0038] The subtractor 23 receives the current command P5 output by the speed control unit 122 and the actual current P10 output by the condition monitoring unit 4. The actual current P10 is the actual current value when the motor 2 is running. The subtractor 23 subtracts the actual current P10 from the current command P5 to calculate the current deviation P6, which is the difference between the current command P5 and the actual current P10. The subtractor 23 outputs the calculated current deviation P6 to the current control unit 123.

[0039] The current control unit 123 calculates the drive current P7 through power conversion based on the current deviation P6 and outputs the drive current P7, thereby supplying power to the motor 2. In describing the control of the position control unit 121 and the speed control unit 122, PID control is used as an example here, but the control is not limited to PID control. The position control unit 121 and / or the speed control unit 122 can perform control using PI control, P control, or feedforward compensation in combination.

[0040] The operation of the data switching unit 13 will now be described in detail. Fig. 3 is a flowchart illustrating the flow of a procedure performed by the data relay unit included in an abnormality diagnosis apparatus according to the first embodiment.

[0041] The data exchange unit 13 obtains the speed control gain P9 set in the drive control unit 12A, which is a driving device, from the drive control unit 12A (step S1). The data exchange unit 13 calculates the speed control bandwidth based on the speed control gain P9 (step S2).

[0042] An example of calculating the control bandwidth based on the control gain D1 will now be described. A processing example of a procedure for calculating the speed control bandwidth, which is an example of the control bandwidth, from the speed control gain P9, which is an example of the control gain D1, will be described here.

[0043] Fig. 4 is a diagram for explaining a method of calculating the control bandwidth from the control gain performed by an abnormality diagnosis apparatus according to the first embodiment. Fig. 4 shows a block diagram focusing on the transmission characteristics of the motor 2, the prime mover 3, the condition monitoring unit 4 and the drive control unit 12A. Fig. 4 illustrates a case where the drive control unit 12A performs proportional control.

[0044] In Fig. 4, the motor 2 and the prime mover 3 are considered as rigid bodies, where J is the sum of the inertia of the motor 2 and the inertia of the prime mover 3. s is the Laplace operator. K vp is the speed control gain and K t is a constant for the conversion of current into torque.

[0045] In Fig. 4, the control bandwidth of the current control unit 123 is assumed to be significantly higher than the control bandwidth of the speed control unit 122 and to be direct and current command P5 = actual current P10. Fig. 4 illustrates a case where the speed command P3 output from the command generation unit 11 is input to the speed control unit 122, the current command P5 (the actual current P10) output from the speed control unit 122 is input to the motor 2, and the current control unit 123 is omitted.

[0046] The speed command P3 from the command generation unit 11 and the actual speed P8x detected at the motor 2 are input to the subtractor 24. The subtractor 24 calculates the speed deviation P4 by subtracting the actual speed P8x from the speed command P3 and outputs the calculated speed deviation P4 to the speed control unit 122.

[0047] The speed deviation P4 is given by K vp in the speed control unit 122 to the torque command P12. The torque command P12 is under the action of 1 / K t in the speed control unit 122 to the current command P5. The current command P5 is under the action of K tin motor 2 to the actual torque P13. The actual torque P13 is converted to the actual speed P8x by 1 / Js in motor 2. The actual speed P8x is sent to the speed control unit 122. The speed control unit 122 performs control based on the actual speed P8x, thereby implementing a closed-loop control. In this case, a closed-loop control transfer function G(s) from the speed command P3 to the actual speed P8x is expressed by Equation (1) below, which is a first-order lag transfer function. Equation 1: G(s)=KνpJs+KνpJ

[0048] Therefore, the transfer function from the speed command P3 to the actual speed P8x has a first-order lag characteristic, which is represented by a frequency ω shown in the following equation (2) sc, where it has the property of having a frequency of approximately ω sc or lower, but blocks frequencies higher than ω sc are. Equation 2: ωsc=KνpJ

[0049] ω sc is the speed control bandwidth and can be calculated from the speed control gain K vp can be calculated using equations (1) and (2) above. Even if Fig. 4 the case of performing proportional control was described as an example, the speed control bandwidth can also be calculated in PI or PID control if the proportional gain is defined as K vp is considered.

[0050] Next, the data exchange unit 13 acquires the resonance frequency D3 of the prime mover 3 (step S3). The data exchange unit 13 stores the previously measured resonance frequency D3 and acquires the resonance frequency D3 by reading the stored resonance frequency D3. The resonance frequency D3 can be stored outside the data exchange unit 13.

[0051] Next, the data switching unit 13 calculates the threshold based on the resonance frequency D3 of the drive machine 3 (step S4). For example, the data switching unit 13 sets the threshold = resonance frequency D3 or the threshold = resonance frequency D3×c. Here, c is in the range of approximately 0.5≤c≤2, for example.

[0052] Next, the data switching unit 13 compares the speed control bandwidth with the threshold and determines whether the speed control bandwidth is below the threshold (step S5). The data switching unit 13 thus determines whether the speed control bandwidth is lower than the threshold.

[0053] If it is determined that the speed control bandwidth is lower than the threshold (step S5, Yes), the data switching unit 13 selects the actual position P11 as the data type (step S6) and outputs the actual position P11 to the abnormality determination unit 14. That is, the data switching unit 13 selects the actual position P11 from the time series data D2 and outputs the selected actual position P11 to the abnormality determination unit 14 as the selected time series data D5.

[0054] On the other hand, if the data switching unit 13 determines that the speed control bandwidth is higher than the threshold (step S5, No), it selects the actual stream P10 as the data type (step S7) and outputs the actual stream P10 to the anomaly determination unit 14. That is, the data switching unit 13 selects the actual stream P10 from the time series data D2 and outputs the selected actual stream P10 to the anomaly determination unit 14 as the selected time series data D5.

[0055] Here, an example was described where the selected data is the actual current P10 or the actual position P11. However, the actual current P10 can be replaced by the current command P5 for driving motor 2, the torque command P12 for driving motor 2 or prime mover 3, the actual torque P13 detected by motor 2 or prime mover 3, the disturbance torque estimate value, which is an estimate of a disturbance torque on motor 2 or prime mover 3, the current deviation P6, or a torque deviation (difference between the torque command P12 for motor 2 and the actual torque P13).The actual position P11 can be replaced by the speed command P3 to the motor 2 or the prime mover 3, the actual speed P8 of the motor 2 or the prime mover 3, the acceleration of the motor 2 or the prime mover 3, the position deviation P2 of the motor 2 or the prime mover 3, or the speed deviation P4 of the motor 2 or the prime mover 3. The acceleration data of the motor 2 or the prime mover 3 also includes vibration information.

[0056] Thus, when the speed control bandwidth is higher than the threshold, the data switching unit 13 selects the selected time series data D5 for output to the anomaly determination unit 14 from a first data group of the time series data D2. On the other hand, when the speed control bandwidth is lower than the threshold, the data switching unit 13 selects the selected time series data D5 from a second data group of the time series data D2 for output to the anomaly determination unit 14.

[0057] The first data group includes the actual current P10, the current command P5, the torque command P12, the actual torque P13, the disturbance torque estimate, the current deviation P6, or the torque deviation. The second data group includes the actual position P11, the speed command P3, the actual speed P8, the acceleration, the position deviation P2, or the speed deviation P4.

[0058] If the speed control bandwidth is higher than the threshold, the data switching unit 13 may select one or more individual data items from the first data group. If the speed control bandwidth is lower than the threshold, the data switching unit 13 may select one or more individual data items from the second data group.

[0059] The configuration of a drive control unit when calculating an estimated value for a disturbance torque is now described. Fig. 5 is a diagram showing another example of the configuration of a drive control unit included in an abnormality diagnosis apparatus according to the first embodiment. Fig. Figure 5 shows the configuration of a drive control unit 12B that estimates a disturbance torque estimate P14. The drive control unit 12B includes, in addition to the components of the drive control unit 12A, a disturbance observer 125. The disturbance observer 125 is connected to the speed converter unit 124 and the speed control unit 122.

[0060] In the drive control unit 12B, the speed control unit 122 calculates the torque command P12 corresponding to the current command P5. Specifically, the speed control unit 122 calculates the torque command P12 by multiplying the current command P5 by the torque constant (the conversion constant K t ) of motor 2. The speed control unit 122 outputs the calculated torque command P12 to the disturbance observer 125. The speed conversion unit 124 outputs the calculated actual speed P8 to the subtractor 22 and the disturbance observer 125.

[0061] The disturbance observer 125 calculates the disturbance torque estimate P14 based on the torque command P12 and the actual speed P8. Specifically, the disturbance observer 125 calculates the disturbance observer 125 by subtracting from the torque command P12 data obtained by multiplying data obtained by differentiating the actual speed P8 by the total value of the inertia of the motor 2 and the inertia of the prime mover 3. The disturbance observer 125 outputs the calculated disturbance torque estimate P14 to the data relay unit 13.

[0062] As described above, the abnormality diagnosis device 1A for the motor 2 or the prime mover 3 selects data in which abnormalities are likely to occur (the selected time series data D5) based on the relationship between a physical characteristic (the resonance frequency D3) of the prime mover 3 or the motor 2 and the control bandwidth, and performs abnormality diagnosis for the motor 2 or the prime mover 3 based on the selected data. Consequently, the abnormality diagnosis device 1A can reduce or avoid an increase in the computational load and reduce or prevent a decrease in the accuracy of the abnormality diagnosis because redundant data (data with little relevance to abnormalities) is not used. Furthermore, the abnormality diagnosis device 1A does not require expertise and time to select data when performing abnormality diagnosis on the motor 2 or the prime mover 3.Thus, the abnormality diagnosis device 1A can perform abnormality diagnosis of the engine 2 or the prime mover 3 in a simple manner and with high accuracy.

[0063] The reason why the abnormality diagnosis device 1A can perform abnormality diagnosis of the motor 2 or the prime mover 3 simply and with high accuracy will now be described in detail. When an abnormality occurs in the prime mover 3, the abnormality affects the motor 2 as a disturbance, which is reflected in the actual current P10 and / or the actual position P11 output from the condition monitoring unit 4. That is, when an abnormality occurs in the prime mover 3, at least one of the actual current P10 and the actual position P11 output from the condition monitoring unit 4 shows an abnormal numerical value. When an abnormality occurs in the prime mover 3, for example, micro-vibrations at the resonance frequency D3 of the prime mover 3 or a frequency close to the resonance frequency D3 occur, which affect the motor 2 as a disturbance.

[0064] When the drive control unit 12A controls the motor 2 in a feedback loop, whether a disturbance of a specific frequency is easily suppressed or not depends on the control bandwidth determined from the control gain D1. For example, the larger the control bandwidth, the wider the range of frequencies that can be suppressed in the drive control unit 12A.

[0065] For example, if the frequency of a disturbance is lower than the speed control bandwidth, the disturbance is unlikely to affect the actual position P11, which is a controlled variable. However, this does not mean that the effect does not occur at all in the actual position P11; however, a frequency caused by the disturbance vibration will still appear slightly. If the control bandwidth is larger than the frequency of the disturbance vibration, the control gain D1 corresponding to the control bandwidth also increases.

[0066] When establishing a feedback loop, the drive control unit 12A multiplies the deviation between command data such as the position command P1 or the speed command P3 and a controlled variable such as the actual position P11 or the actual speed P8 by the control gain D1 to calculate a manipulated variable. In the abnormality diagnosis device 1A, when the control gain D1 is large, the actual position P11 or the actual speed P8, which contain a small frequency component of the disturbance, becomes larger, so that the frequency of the disturbance is likely to appear in the current command P5, which is the manipulated variable.

[0067] On the other hand, if the frequency of a disturbance is higher than the speed control bandwidth, the drive control unit 12A cannot completely eliminate the effect of the disturbance even if a feedback loop is created, and the disturbance is likely to affect the controlled variable. Consequently, the frequency of the disturbance is likely to appear in the actual position P11, which is the controlled variable.

[0068] The torque command P12, which represents a manipulated variable, only compensates for disturbances through a feedback loop to a limited extent. Thus, the torque command P12 has the property that the frequency of a disturbance is unlikely to occur.

[0069] Thus, the abnormality diagnosis device 1A of the first embodiment compares the control bandwidth determined from the control gain D1 with the threshold value calculated based on the resonance frequency D3 determined by the engine 3, and automatically selects data conducive to the excitation of the frequency of a disturbance associated with an abnormality (the selected time series data D5) based on the comparison result. Then, the abnormality determination unit 14 of the abnormality diagnosis device 1A determines an abnormality in the engine 3 or the motor 2 based on the selected time series data D5, and can thus accurately detect an abnormality.

[0070] Instead of the actual current P10, the data switching unit 13 may select the current command P5, the torque command P12 proportional to the current command P5, the actual torque P13, the current deviation P6 obtained by subtracting the actual current P10 from the current command P5, the torque deviation obtained by subtracting the actual torque P13 from the torque command P12, or the disturbance torque estimate P14. In this case, the frequency component of the resonance frequency D3 superimposed on the actual current P10 is also superimposed on various types of processed data calculated from the actual current P10 or from data selected instead of the actual current P10, so that the anomaly diagnosis device 1A can achieve effects equivalent to those when the actual current P10 is selected.

[0071] Instead of the actual position P11, the data exchange unit 13 may select the actual speed P8 obtained by differentiating the actual position P11, the acceleration obtained by twice differentiating the actual position P11, the position deviation P2 obtained by subtracting the actual position P11 from the position command P1, or the speed deviation P4 obtained by subtracting the actual speed P8 from the speed command P3. In this case, the frequency component of the resonance frequency D3 superimposed on the actual position P11 is also superimposed on various types of processed data calculated from the actual position P11 or data selected instead of the actual position P11, so that the abnormality diagnosis device 1A can achieve effects equivalent to those when the actual position P11 is selected.

[0072] Although the first embodiment described the case where the threshold value determined by the prime mover 3 is the resonance frequency D3, the threshold value is not limited to the resonance frequency D3. For example, the resonance frequency D3 determined by the prime mover 3 may vary depending on the operating conditions, and the threshold value may deviate slightly from the resonance frequency D3 depending on the setting of the control gain D1. Therefore, in the abnormality diagnosis apparatus 1A as described above, a value obtained by multiplying the resonance frequency D3 of the prime mover 3 by a certain constant c (e.g., approximately 0.5≤c≤2) may be set as the threshold value determined by the prime mover 3.

[0073] Note that the control bandwidth is not limited to the speed control bandwidth and can be a position control bandwidth or a current control bandwidth (torque control bandwidth). When the control bandwidth is the position control bandwidth or the current control bandwidth (torque control bandwidth), the data switching unit 13 calculates the threshold based on the resonance frequency D3.

[0074] As described above, in the first embodiment, the abnormality diagnosis device 1A conveys the selected time-series data D5 to be selected and output from the time-series data D2 indicating the state of the engine 2 or the prime mover 3 based on the result of a comparison between the control bandwidth determined from the control gain D1 and the threshold value determined from the prime mover 3. Then, the abnormality diagnosis device 1A determines an abnormal state of the engine 2 or the prime mover 3 based on the selected time-series data D5. Thus, the abnormality diagnosis device 1A can select collected data and analyze the data, and consequently determine an abnormal state with a small amount of data that does not contain redundant data with little relevance to abnormalities. Therefore, the abnormality diagnosis device 1A can perform highly accurate abnormality diagnosis.In addition, the anomaly diagnosis device 1A can perform anomaly diagnosis in a short time. Second embodiment

[0075] Next, a second embodiment will be described with reference to the Fig. 6 to 8. In the second embodiment, among the selected time series data D5 on which a disturbance associated with an abnormality is likely to be superimposed, data in which the operating state of the engine 2 or the prime mover 3 is in an acceleration or deceleration phase is selected as data more advantageous for determining an abnormality and performing anomaly diagnosis.

[0076] Fig. Fig. 6 is a diagram illustrating an example of the configuration of an abnormality diagnosis device according to the second embodiment. Of the components in Fig. 6 are components that have the same functions as the components of the Fig. 1 shown abnormality diagnosis apparatus 1A of the first embodiment are provided with the same reference numerals without duplicate description.

[0077] An abnormality diagnosis device 1B of the second embodiment includes, in addition to the components included in the abnormality diagnosis device 1A, an operation determination unit 15. The operation determination unit 15 is connected to the command generation unit 11 and the data exchange unit 13.

[0078] The operation determination unit 15 receives, for example, a command value generated and output by the command generation unit 11. The operation determination unit 15 determines the operating state of the motor 2 or the prime mover 3, for example, based on the command value generated by the command generation unit 11. Specifically, when the command generation unit 11 generates the position command P1, the operation determination unit 15 calculates a target speed P21 by differentiating the position command P1 and determines the operating state of the motor 2 or the prime mover 3 based on the calculated target speed P21. The operation determination unit 15 outputs operation information P22 indicating the operating state to the data exchange unit 13.

[0079] An example of the target speed P21 is now described. Fig. Fig. 7 is a diagram illustrating an example of a target speed used by an abnormality diagnosis device according to the second embodiment. The horizontal axis of the Fig. The representation shown in Figure 7 indicates the time, the vertical axis indicates the target speed P21.

[0080] As in Fig. As shown in Figure 7, the target speed P21 is divided into an acceleration phase in which the absolute value of the speed (operation speed) increases, a constant-speed phase in which the absolute value of the speed is a constant value greater than 0 (rpm), a deceleration phase in which the absolute value of the speed decreases, and a stop phase in which the target speed P21 is constantly at 0 (rpm). The operation determination unit 15 determines which phase the target speed P21 corresponds to at a certain time and outputs the operation information P22, which is a determination result, to the data exchange unit 13. The operation determination unit 15 outputs the operation information P22 for each time to the data exchange unit 13.

[0081] Next, the operation of the data switching unit 13 is described in detail. Fig. Fig. 8 is a flowchart illustrating the flow of a procedure performed by a data exchange unit included in an abnormality diagnosis apparatus according to the second embodiment. Fig. The procedure shown in Figure 8 does not describe the part corresponding to Fig. 3 performed by the abnormality diagnosis apparatus 1A of the first embodiment.

[0082] The abnormality diagnosis device 1B of the second embodiment performs the procedure of steps S1 to S7 like the abnormality diagnosis device 1A. That is, in steps S1 to S7, the abnormality diagnosis device 1B selects the type of data (the selected time series data D5) based on the speed control bandwidth calculated from the speed gain and the threshold value calculated from the resonance frequency D3.

[0083] The abnormality diagnosis device 1B performs the procedure of steps S11 to S13 after steps S6 and S7. Specifically, the data relay unit 13 of the abnormality diagnosis device 1B obtains the operation information P22 output from the operation determination unit 15 (step S11).

[0084] Next, the data switching unit 13 determines whether the operating state indicated by the operating information P22 corresponds to the acceleration phase or the deceleration phase (step S12). If the operating state indicated by the operating information P22 is the acceleration phase or the deceleration phase (step S12, Yes), the data switching unit 13 selects the acceleration phase or the deceleration phase as the data interval to be selected from the selected time series data D5 (step S13). Then, the data switching unit 13 samples (selects) the selected time series data D5 including the time period of the acceleration phase or the deceleration phase of the selected time series data D5 and outputs the sampled selected time series data D5 to the abnormality determination unit 14.

[0085] If, in step S12, the operating state indicated by the operating information P22 is neither the acceleration phase nor the deceleration phase (step S12, No), the data relay unit 13 does not output the selected time series data D5 to the abnormality determination unit 14. Accordingly, if the operating state of the engine 2 or the prime mover 3 is neither the acceleration phase nor the deceleration phase, the data relay unit 13 does not output the selected time series data D5 to the abnormality determination unit 14.

[0086] In the data switching procedure of the first embodiment, data selection is automatically directed so that data likely to be superimposed by a disturbance associated with an anomaly, that is, data advantageous for the anomaly determination unit 14 to perform the anomaly determination (the selected time series data D5), can be input to the anomaly determination unit 14.

[0087] To extract data that is even more advantageous for determining abnormalities, the abnormality diagnosis device 1B of the second embodiment performs data interval selection in addition to data type selection. During the acceleration phase or deceleration phase, the motor 2 and the prime mover 3 operate in steep mode. Consequently, a large excitation force is applied to the motor 2 and the prime mover 3. A large excitation force is more likely to excite vibrations, and a large vibration component is more likely to be included in an abnormality-related disturbance.Therefore, the data switching unit 13 cuts out only the selected time series data D5 of the acceleration phase or the deceleration phase and outputs the cut-out selected time series data D5 to the anomaly determination unit 14, so that the anomaly determination unit 14 can perform anomaly determination with higher accuracy than in the first embodiment.

[0088] Although the abnormality diagnosis device 1B of the second embodiment determines whether the operation state is the acceleration phase, the deceleration phase, the constant speed phase, or the stop phase based on the target speed P21, the abnormality diagnosis device 1B may determine the operation state based on data other than the target speed P21. For example, the operation determination unit 15 may determine whether the operation state is the acceleration phase, the deceleration phase, the constant speed phase, or the stop phase based on the actual speed P8 of the motor 2 or the prime mover 3, or based on data obtained by filtering the target speed P21 or the actual speed P8. The operation determination unit 15 may cut out data in only the acceleration phase, only the deceleration phase, or both phases.The operation determination unit 15 thus cuts out data in the acceleration phase and / or the deceleration phase.

[0089] In the second embodiment, a motor 2 and a prime mover 3 were described in which a failure associated with an abnormality is likely to occur in the acceleration phase or deceleration phase. However, there are also prime movers 3 in which a failure associated with an abnormality is attributable to a friction phenomenon. In such a prime mover 3, the abnormality diagnosis device 1B can perform highly accurate abnormality diagnosis by extracting data from the constant-speed phase instead of the acceleration phase or deceleration phase.

[0090] As described above, the abnormality diagnosis apparatus 1B according to the second embodiment performs abnormality diagnosis on the selected time series data D5 of the acceleration phase, the deceleration phase, the constant speed phase, or the stop phase, so that the abnormality diagnosis can be performed with higher accuracy than in the first embodiment. Third embodiment

[0091] Next, a third embodiment will be described with reference to the Fig. 9 to 13. In the first embodiment, the selection of data advantageous for determining abnormalities was described as an example, using a threshold value determined from the resonance frequency D3 of the prime mover 3 when an abnormality occurs in the prime mover 3. The third embodiment describes another example of a threshold value calculated from the prime mover 3.

[0092] Fig. Fig. 9 is a diagram showing an example of the configuration of an abnormality diagnosis device according to the third embodiment. Of the components of the Fig. 9 are the components that have the same functions as the components of the Fig. 1 shown abnormality diagnosis apparatus 1A of the first embodiment are provided with the same reference numerals without duplicate description.

[0093] An abnormality diagnosis device 1C of the third embodiment differs from the abnormality diagnosis device 1A in that a data switching unit 13C is provided instead of the data switching unit 13. The data switching unit 13C and the data switching unit 13 differ in data input.

[0094] The control gain D1, the time-series data D2, the actual speed P32 of the motor 2, and the number of teeth P31 on the prime mover 3 per revolution of the motor 2 are input to the data exchange unit 13C of the abnormality diagnosis device 1C. Specifically, the control gain D1 and the time-series data D2 from the drive control unit 12A and the actual speed P32 of the motor 2 from the condition monitoring unit 4 are input to the data exchange unit 13C. The number of teeth P31 is input to the data exchange unit 13C from an external device. The number of teeth P31 is the number of teeth of the prime mover 3 that rotate when the motor 2 makes one revolution. Note that the number of teeth P31 can be input to the data exchange unit 13C by the user.

[0095] The third embodiment describes a case where the Fig. 9, the drive machine 3 shown is a drive machine with gears. Fig. 10 is a diagram showing an example of the configuration of gears included in a prime mover on which abnormality diagnosis is performed by an abnormality diagnosis apparatus according to the third embodiment.

[0096] Fig. Figure 10 shows spur gears as an example of the gears included in the drive machine 3. In the drive machine 3, the power of the engine 2 is transmitted via a drive-side gear 44 to a load-side gear 43, thereby driving a mechanical load 41 connected to the load-side gear 43.

[0097] Next, the operation of the data switching unit 13C will be described in detail. Fig. Fig. 11 is a flowchart illustrating the flow of a procedure performed by a data exchange unit included in an abnormality diagnosis apparatus according to the third embodiment. Fig. 11, the part corresponding to the procedure described in Fig. 3 performed by the abnormality diagnosis apparatus 1A of the first embodiment.

[0098] Compared with the abnormality diagnosis device 1A, the abnormality diagnosis device 1C of the third embodiment performs the procedure of steps S21 to S24 instead of steps S3 and S4. Therefore, the abnormality diagnosis device 1C performs the procedure of steps S21 to S24 after the procedure of steps S1 and S2, and then the procedure of steps S5 to S7.

[0099] Specifically, the data switching unit 13C obtains the speed control gain P9 from the drive control unit 12A (step S1) and calculates the speed control bandwidth based on the speed control gain P9 (step S2).

[0100] Subsequently, the data exchange unit 13C obtains the number of teeth P31 on the drive machine 3 per revolution of the motor 2 (step S21). The number of teeth P31 is inputted into the data exchange unit 13C in advance. The data exchange unit 13C stores the inputted number of teeth P31 and obtains the number of teeth P31 by reading the stored number of teeth P31. For example, the drive-side gear 44 and the load-side gear 43 shown in Fig. 10, each have sixteen teeth, so that the number of teeth P31 is sixteen.

[0101] Next, the data exchange unit 13C obtains the actual speed P32 of the motor 2 from the condition monitoring unit 4 (step S22). Then, the data exchange unit 13C calculates a meshing frequency based on the acquired number of teeth P31 and the acquired actual speed P32 of the motor 2 (step S23). The meshing frequency is a frequency indicating how often the teeth provided on the mechanical parts collide with each other per unit time during operation of the motor 2. As an example, the meshing frequency of the drive-side gear 44 and the load-side gear 43 shown in Fig. 10. Since the Fig. 10 have a gear ratio of 1:1, the meshing frequency fm [Hz] is determined based on the actual speed P32 (=actual speed V fb[rpm]) and the number of teeth P31 (=number of teeth Z) obtained in step S21 by the following equation (3). Equation 3: ƒm=Vƒb60∗Z

[0102] Next, the data exchange unit 13C calculates the threshold based on the calculated intervention frequency (step S24). Like the abnormality diagnosis device 1A of the first embodiment, the abnormality diagnosis device 1C sets, for example, the threshold = intervention frequency or the threshold = intervention frequency xc, where c is in the range of approximately 0.5≤c≤2. Then, the abnormality diagnosis device 1C performs the procedure of steps S5 to S7 like the abnormality diagnosis device 1A.

[0103] Next, the effects of the third embodiment and the reason for achieving the effects will be described. The abnormality diagnosis device 1A of the first embodiment selects the type of data (the selected time series data D5) to be output to the abnormality determination unit 14 based on the result of a comparison between the threshold value calculated from the resonance frequency D3 of the engine 3 and the speed control bandwidth determined from the speed control gain P9.

[0104] In contrast, when the prime mover 3 includes a power transmission mechanism that uses the meshing of mechanical parts, the abnormality diagnosis apparatus 1C of the third embodiment selects the type of data to be output to the abnormality determination unit 14 (the selected time series data D5) based on the result of a comparison between the threshold value calculated from the meshing frequency of the prime mover 3 and the speed control bandwidth determined from the speed control gain P9.

[0105] In a prime mover 3 including mechanical parts that transmit power through meshing in the transmission mechanism, such as the drive-side gear 44 and the load-side gear 43, the excitation force generated at the time of tooth abutment tends to cause a disturbance associated with an abnormality in the meshing frequency or a frequency close to the meshing frequency. Therefore, the abnormality diagnosis device 1C calculates the meshing frequency, and the data relay unit 13C selects data favorable for determining the abnormality based on the result of a comparison between the threshold value calculated from the meshing frequency and the control bandwidth calculated from the speed control gain P9.Consequently, the abnormality diagnosis device 1C can accurately detect abnormalities even when the prime mover 3 has mechanical parts such as the drive-side gear 44 and the load-side gear 43 that transmit power by meshing in the transmission mechanism.

[0106] Depending on the prime mover 3, an abnormality-related disturbance may occur not only at the engagement frequency but also at a frequency close to the engagement frequency, such as a sideband. Therefore, as described above, the data relay unit 13C of the abnormality diagnosis device 1C may set a value obtained by multiplying the engagement frequency by the specific constant c (e.g., approximately 0.5≤c≤2) as the threshold value determined for the prime mover 3.

[0107] Although in the third embodiment, an example was described in which the abnormality diagnosis device 1C calculates the intervention frequency from the actual speed P32 (actual speed=V fb ), the abnormality diagnosis device 1C can calculate the intervention frequency from data other than the actual speed P32. For example, the abnormality diagnosis device 1C can calculate speed information about the motor 2 based on a command speed obtained by differentiating the position command P1, and then calculate the intervention frequency based on the speed information.

[0108] Although in the third embodiment the case has been described that the drive machine comprises 3 spur gears, as in Fig. As shown in Figure 10, the drive machine 3 can be any drive machine for which the meshing frequency can be calculated. For example, the drive machine 3 can be a drive machine for which the meshing frequency can be calculated from the number of teeth P31 per revolution of the motor 2 and the speed information of the motor 2, such as a drive machine with a planetary gear or a drive machine with pulleys used to tension a toothed belt.

[0109] Here, the case was described where the number of teeth of the gears on the motor side 2 : the load side = Z:Z (1:1). But even if the number of teeth of the gears on the motor side 2 : the load side = Z:Z1 (Z <Z1) ist, erhält man die Eingriffsfrequenz fm [Hz] durch die oben beschriebene Gleichung (3). Wenn die Anzahl der Zähne der Zahnräder auf der Seite des Motors 2 : der Lastseite=Z2:Z (Z2> Z), the data switching unit 13C can obtain the intervention frequency fm [Hz] by setting Z=Z2 in equation (3).

[0110] In the third embodiment, a case where gears are an example of the transmission mechanism was described, but the transmission mechanism is not limited to gears. For example, a wave gear device can be used as another example instead of gears for the transmission mechanism.

[0111] A case will now be described where the transmission mechanism is a wave gear device. As is well known, when the motor 2 drives a load through the wave gear device, vibration occurs at a frequency twice the motor speed, i.e., a frequency fm2 [Hz] in equation (4) below, due to the structure of the wave gear device. When an abnormality occurs in the transmission mechanism, an abnormality also occurs at the frequency fm2 [Hz] of equation (4). When the wave gear device is used as the transmission mechanism, a threshold value is obtained from equation (4) so ​​that abnormalities can be detected with high accuracy. Equation 4: ƒm2=Vƒb60∗2

[0112] A rolling bearing can be used as the transmission mechanism. Rolling bearings are used in motor 2 and also in drive unit 3. Here, we will describe the case where the transmission mechanism is a rolling bearing.

[0113] Fig. 12 is a diagram showing an example of the configuration of a rolling bearing on which an abnormality diagnosis is performed by an abnormality diagnosis apparatus according to the third embodiment. Fig. 13 shows a diagram explaining the contact angle of a Fig. 12 shown rolling bearing.

[0114] A rolling bearing 50 includes an inner ring 52, rolling elements 53, an outer ring 51, a cage (not shown), and other elements. It is known that in the rolling bearing 50, the frequency of an abnormality varies depending on a defective part (such as the inner ring 52, the rolling elements 53, or the outer ring 51) or a failure factor (such as chipping 60 or abrasion).

[0115] For example, if a chipping 60 occurs in the inner ring 52, as in Fig. As shown in Figure 12, an anomaly occurs at a frequency fm3 [Hz] in the following equation (5). In equation (5), n is the number of rolling elements 53, d is the diameter of the balls (of the rolling elements 53), D is the pitch diameter, and ϕ is the contact angle of the rolling bearing 50. Equation 5: ƒm3=n∗Vƒb60∗(1+dDcosϕ)

[0116] The contact angle ϕ is an angle formed by a line of action 56 in the rolling bearing 50 and a plane 57 perpendicular to the center axis of the rolling bearing 50. Each rolling element 53 is in contact with an outer bearing ring, which is a bearing ring of the outer ring 51, at a point 54 and with an inner bearing ring, which is a bearing ring of the inner ring 52, at a point 55. The line of action 56 of the load is a line connecting these two points 54 and 55. When the rolling bearing 50 is mounted on the prime mover 3, the threshold value is determined using equation (5), so that abnormalities can be detected with high accuracy.

[0117] When chipping 60 or other defects occur in the rolling elements 53, the outer ring 51, or other elements, the anomaly diagnosis device 1C can also calculate the frequency of anomaly occurrence using a known mathematical formula to determine the threshold. Even when other failure factors occur, the anomaly diagnosis device 1C can calculate the frequency using a known mathematical formula to determine the threshold.

[0118] Furthermore, the transmission mechanism may be a transmission mechanism combining gears, a wave transmission device, a rolling bearing 50, a belt, etc. Even if various types or combinations of transmission mechanisms are used, a common feature of the above-described gears, the wave transmission device, the rolling bearing 50, etc. is that the vibration is proportional to the speed of the motor 2 due to the structure. Therefore, even if various types or combinations of transmission mechanisms are used, vibration proportional to the rotation frequency of the motor 2 is likely to occur. If an abnormality occurs, vibration proportional to the speed of the motor 2 will also occur.In this case, a value proportional to a frequency calculated from the speed information of motor 2 is chosen as the threshold so that anomalies can be detected with high accuracy.

[0119] As described above, the abnormality diagnosis device 1C according to the third embodiment selects the data type to be output to the abnormality determination unit 14 based on the result of a comparison between the threshold value calculated from the engagement frequency of the engine 3 and the speed control bandwidth determined from the speed control gain P9. Therefore, the abnormality diagnosis device 1C can perform abnormality diagnosis easily and with high accuracy, as in the first embodiment. Fourth embodiment

[0120] Next, a fourth embodiment will be described with reference to the Fig. 14 and Fig. 15. In the first embodiment, an example of selecting data favorable for abnormality determination was described using a threshold value determined from the resonance frequency D3 of the prime mover 3 when an abnormality occurs in the prime mover 3. In the fourth embodiment, when the actual current P10 is selected in the first embodiment, data favorable for abnormality determination is again selected based on the driving state of the motor 2.

[0121] Fig. Fig. 14 is a diagram showing an example of the configuration of an abnormality diagnosis device according to the fourth embodiment. Of the components of the Fig. 14 are the components that have the same functions as the components of the Fig. 1 shown in Fig. 1 are designated by the same reference numerals and will not be described twice.

[0122] An abnormality diagnosis device 1D of the fourth embodiment differs from the abnormality diagnosis device 1A in that a data switching unit 13D is provided instead of the data switching unit 13. The data switching unit 13D and the data switching unit 13 differ in the data input.

[0123] The control gain D1, the time-series data D2, the actual current P10 corresponding to the drive current P7 of the motor 2, and a current threshold P41 are input to the data exchange unit 13D of the abnormality diagnosis device 1D. Specifically, the control gain D1, the time-series data D2, and the actual current P10 are input to the data exchange unit 13D from the drive control unit 12, and the current threshold P41 is input by the user. The actual current P10 can be input to the data exchange unit 13D from the condition monitoring unit 4. The current threshold P41 is a threshold value for the effective value of the actual current P10. The current threshold P41 is used to determine whether the data type (the object to be selected) should be changed from the actual current P10 to the actual position P11.

[0124] Next, the operation of the data switching unit 13D will be described in detail. Fig. Fig. 15 is a flowchart illustrating the flow of a procedure performed by a data exchange unit included in an abnormality diagnosis apparatus according to the fourth embodiment. Fig. 15, the part corresponding to the procedure described in Fig. 3 shown abnormality diagnosis device 1A of the first embodiment.

[0125] Compared with the abnormality diagnosis device 1A, the abnormality diagnosis device 1D of the fourth embodiment performs the procedure of steps S41 to S44 after step S7. The abnormality diagnosis device 1D performs the same procedure as the abnormality diagnosis device 1A in steps S1 to S7.

[0126] After the procedure of steps S1 to S7, the abnormality diagnosis device 1D executes the procedure of steps S41 to S44. Accordingly, if the speed control bandwidth is higher than the threshold, the data switching unit 13D selects the actual stream P10 as the data type and then executes the procedure of steps S41 to S44.

[0127] Specifically, after selecting the actual current P10 as the data type, the data exchange unit 13D obtains the effective value of the actual current P10 for the last N seconds from the drive control unit 12A (step S41). Where N is a real number greater than 0.

[0128] Next, the data switching unit 13D acquires the current threshold P41 (step S42). The user presets the current threshold P41 in the data switching unit 13D. The data switching unit 13D stores the current threshold P41 preset by the user and acquires the current threshold P41 by reading the stored current threshold P41.

[0129] Then, the data switching unit 13D compares the acquired effective value of the actual current P10 with the acquired current threshold P41 and determines whether the effective value of the actual current P10 is less than the current threshold P41 (step S43). That is, the data switching unit 13D determines whether the effective value of the actual current P10 is less than the current threshold P41.

[0130] If it is determined that the effective value of the actual current P10 is less than the current threshold P41 (step S43, Yes), the data relay unit 13D selects the actual position P11 as the data type (step S44) and outputs the actual position P11 to the abnormality determination unit 14. That is, if the effective value of the actual current P10 is less than the current threshold P41, the data relay unit 13D changes the data type to be selected from the actual current P10 to the actual position P11.

[0131] On the other hand, if it is determined that the effective value of the actual current P10 is larger than the current threshold P41 (step S43, No), the data switching unit 13D directly outputs the actual current P10 selected in step S7 to the abnormality determination unit 14 without selecting the data type again.

[0132] If it is determined that the effective value of the actual current P10 and the current threshold P41 are the same, the data switching unit 13D may select the actual position P11 as the data type or not select the data type again.

[0133] An example was described here where the selected data is the actual current P10 or the actual position P11. However, the selected actual current P10 can be any of the data included in the first data group. Therefore, the selected actual current P10 can be replaced by the current command P5, the torque command P12, the actual torque P13, the disturbance torque estimate P14, the current deviation P6, or the torque deviation.

[0134] The actual position P11 can be any data included in the second data group. That is, the selected actual position P11 can be replaced by the speed command P3, the actual speed P8, the acceleration, the position deviation P2, or the speed deviation P4.

[0135] At least part of the data contained in the first data group is current-related information related to the actual current P10. When deciding whether or not to perform a data type re-selection, the data relay unit 13D determines, based on the current-related information, whether the effective value of the current-related information acquired for a specific past period is lower than a power threshold, which is a threshold for the effective value.

[0136] If the effective value of the power-related information is lower than the power threshold, the data relay unit 13D selects at least one piece of data included in the second data group as the data type and outputs the selected piece of data to the abnormality determination unit 14. On the other hand, if the effective value of the power-related information is higher than the power threshold, the data relay unit 13D does not select the data type again and outputs at least one piece of data included in the second data group selected in step S7 directly to the abnormality determination unit 14.

[0137] Next, the effects of the fourth embodiment and the reason for achieving the effects will be described. The abnormality diagnosis device 1A of the first embodiment selects the type of data (the selected time series data D5) to be output to the abnormality determination unit 14 based on the result of a comparison between the threshold value calculated from the resonance frequency D3 of the engine 3 and the speed control bandwidth determined from the speed control gain P9.

[0138] In contrast, when the actual current P10 is selected as the data type, the abnormality diagnosis device 1D of the fourth embodiment compares the driving state of the motor 2, that is, the effective value of the actual current P10, with the current threshold P41 set by the user. Then, based on the comparison result, the abnormality diagnosis device 1D reselects the data type to be used for abnormality determination. For example, when the friction of the prime mover 3 is low and the speed of the motor 2 needs to be maintained at a constant speed, the motor 2 has no acceleration phase and no deceleration phase, so the actual current P10 required for operation is small.

[0139] When the actual current P10 required for operation is large to a certain extent, it is also somewhat more likely that disturbance related to anomaly will occur in the actual current P10. When the actual current P10 required for operation is small to a certain extent, a disturbance related to anomaly itself will also be extremely small. Therefore, in a situation where the actual current P10 is extremely small, using the actual current P10 to determine the anomaly may affect the accuracy of determining the anomaly. Therefore, when the actual current P10 is small to a certain extent, it is more advantageous to use the actual position P11 instead of the actual current P10 to perform anomaly determination.That is, even if the abnormality diagnosis device 1D has selected the actual current P10 in step S7, it is more advantageous for the abnormality diagnosis to select the actual position P11 to perform the abnormality diagnosis when the effective value of the actual current P10 is lower than the current threshold P41.

[0140] Depending on the operating mode of the motor 2 or the prime mover 3, the actual current P10 may temporarily become small. Therefore, the abnormality diagnosis device 1D acquires the effective value of the actual current P10 for the past N seconds in advance. Then, the abnormality diagnosis device 1D determines whether the acquired effective value of the actual current P10 is lower than the current threshold P41 or not, and selects the actual position P11 as the data type when the effective value of the actual current P10 is lower than the current threshold P41. As described above, even when the prime mover 3 operates with a small actual current P10 of the motor 2, the abnormality diagnosis device 1D reselects the data type to automatically select data favorable for abnormality determination, thereby enabling it to perform abnormality diagnosis on the prime mover 3.

[0141] As described above, the abnormality diagnosis device 1D according to the fourth embodiment selects the actual position P11 as the data type when the effective value of the actual current P10 is lower than the current threshold P41 and performs abnormality diagnosis, whereby abnormality diagnosis can be performed with higher accuracy than in the first embodiment.

[0142] A hardware configuration of the anomaly diagnosis devices 1A to 1D will now be described. The anomaly diagnosis devices 1A to 1D have the same hardware configuration, so only the hardware configuration of the anomaly diagnosis device 1A will be described here.

[0143] Fig.16 is a diagram illustrating an example of a hardware configuration for implementing the abnormality diagnosis device according to the first embodiment. The abnormality diagnosis device 1A can be implemented by an input device 300, a processor 100, a memory 200, and an output device 400. Examples of the processor 100 include a central processing unit (CPU, also called a central processing device, processing device, computing device, microprocessor, microcomputer, or digital signal processor (DSP)) or an LSI (Large Scale Integration) system. Examples of the memory 200 include random access memory (RAM) and read-only memory (ROM).

[0144] The abnormality diagnosis device 1A is implemented by the processor 100, which reads and executes a computer-executable abnormality diagnosis program D6 for performing the functions of the abnormality diagnosis device 1A, which is stored in the memory 200. The abnormality diagnosis program D6, which is a program for performing the functions of the abnormality diagnosis device 1A, is considered a program that causes a computer to execute a procedure or method of the abnormality diagnosis device 1A.

[0145] The abnormality diagnosis program D6 executed by the abnormality diagnosis device 1A has a module configuration including the command generation unit 11, the drive control unit 12A, the data switching unit 13, and the abnormality determination unit 14, which are loaded into a main storage device and generated in the main storage device.

[0146] The input device 300 receives the time series data D2 of the engine 2 or the prime mover 3 from the condition monitoring unit 4 and transmits the time series data D2 to the processor 100. The memory 200 stores the abnormality diagnosis program D6, the control gain D1, the resonance frequency D3 of the prime mover 3, etc.

[0147] The control gain D1, the resonance frequency D3 of the prime mover 3, etc., are read by the processor 100 from the memory 200. The memory 200 is also used as a buffer when the processor 100 performs various types of processing. The output device 400 outputs a determination object of the abnormality determination, a determination item, and a determination result to an external device such as the display device 5.

[0148] The anomaly diagnosis program D6 can be stored on a computer-readable storage medium as a file in an installable format or in an executable format and provided as a computer program product. Alternatively, the anomaly diagnosis program D6 can be provided to the anomaly diagnosis device 1A via a network, such as the Internet. The functions of the anomaly diagnosis device 1A can be implemented partly by dedicated hardware, such as a dedicated circuit, and partly by software or firmware.

[0149] The configurations described in the above embodiments are examples and can be combined with other known techniques. The embodiments can be combined with each other. The configurations can be partially omitted or changed without deviating from the essence. List of reference symbols 1A to 1D anomaly diagnostic device 2 engines 3 Drive machine 4 Condition monitoring unit 5 Display device 11 Command generation unit 12A, 12B drive control unit 13, 13C, 13D Data switching unit 14 Anomaly determination unit 15 Operational determination unit 21 to 24 subtractors 41 mechanical load 43 load-side gear 44 drive-side gear 50 rolling bearings 51 outer race 52 inner race 53 rolling elements 54, 55 point 56 Line of action 57 Level 60 chipping 100 processor 121 Position control unit 122 Speed ​​control unit 123 Power control unit 124 Speed ​​converter unit 125 fault observers 200 storage 300 input device 400 dispensing device D1 Control gain D2 Time series data D3 resonance frequency D5 selected time series data D6 Anomaly Diagnostic Program P1 position command P2 Position deviation P3 speed command P4 Speed ​​deviation P5 current command P6 Current deviation P7 drive current P8, P8x, P32 actual speed P9 Speed ​​control gain P10 actual current P11 actual position P12 Torque command P13 actual torque P14 Disturbance torque estimate P21 Target speed P22 Operating information P31 Number of teeth P41 Current threshold QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2019-024305

[0004]

Claims

[1] Anomaly diagnostic device comprising: a command generation unit for generating a command value to specify the operation of an engine or a prime mover driven by the engine; a drive control unit for performing feedback control on the motor based on a control gain so that the operation of the motor or the prime mover follows the command value; a data switching unit for switching selected time series data by selecting data from time series data indicating a state of the engine or the prime mover based on the result of a comparison between a control bandwidth determined from the control gain and a threshold value determined by the prime mover; and an abnormality determination unit for determining an abnormal state of the engine or the prime mover based on the selected time series data. [2] The abnormality diagnosis apparatus according to claim 1, wherein the data switching unit selects the selected time series data to be output to the abnormality determination unit from a first data group of the time series data when the control bandwidth is higher than the threshold, and selects the selected time series data to be output to the abnormality determination unit from a second data group of the time series data when the control bandwidth is lower than the threshold, the first data group comprising: a current command for driving the motor, a torque command for driving the motor or prime mover, an actual current detected at the motor, an actual torque detected at the motor or prime mover, a disturbance torque estimate which is an estimate of a disturbance torque at the motor or prime mover, a current deviation which is a difference between the current command and the actual current, and a torque deviation which is a difference between the torque command and the actual torque, and the second data group includes: an actual position of the motor or prime mover, a speed command for the motor or prime mover, an actual speed of the motor or prime mover, an acceleration of the motor or prime mover, a position deviation which is a difference between a position command corresponding to the actual position and the actual position, and a speed deviation which is a difference between the speed command and the actual speed. [3] An abnormality diagnosis apparatus according to claim 1 or 2, further comprising: an operation determination unit for determining, based on the command value, whether the time series data corresponds to an acceleration phase or a deceleration phase of the motor or the prime mover, and outputting the determination result as operation information, wherein the data relay unit selects data including the selected time series data of the acceleration phase and / or deceleration phase from the time series data based on the operation information, and outputs the selected data to the anomaly determination unit. [4] An abnormality diagnosis apparatus according to claim 1 or 2, further comprising: an operation determination unit for determining, based on the command value, whether the time series data corresponds to a constant speed phase of the motor or the prime mover or not, and outputting the determination result as operation information, wherein the data switching unit selects data including the selected time series data of the constant speed phase from the time series data based on the operation information, and outputs the selected data to the anomaly determination unit. [5] An abnormality diagnosis apparatus according to claim 1 or 2, further comprising: an operation determination unit for determining, based on the command value, whether the time series data corresponds to a stop phase of the motor or the prime mover or not, and outputting the determination result as operation information, wherein the data relay unit selects data including the selected time series data of the stop phase from the time series data based on the operation information and outputs the selected data to the anomaly determination unit. [6] An abnormality diagnosis apparatus according to any one of claims 1 to 5, wherein the threshold value is a value calculated based on a resonance frequency of the prime mover. [7] An abnormality diagnosis apparatus according to any one of claims 1 to 5, wherein, when the prime mover includes mechanical parts for transmitting power by meshing, the threshold value is a value calculated based on a meshing frequency determined from speed information about the motor and the number of teeth on the mechanical parts. [8] An abnormality diagnosis apparatus according to any one of claims 1 to 5, wherein the threshold value is a value proportional to a frequency calculated from speed information of the motor. [9] The abnormality diagnosis apparatus according to claim 2, wherein the data switching unit changes an object to be selected by selecting the selected time series data to be output to the abnormality determination unit from the second data group of the time series data when the control bandwidth is higher than the threshold and an effective value of current-related information related to the actual current detected at the motor for a certain past period is lower than a power threshold that is a threshold for the effective value. [10] An abnormality diagnosis apparatus according to any one of claims 1 to 9, wherein the time series data includes first data obtained from a condition monitoring unit that monitors the condition of the engine or the prime mover, and / or second data generated by the drive control unit, and / or third data generated by the command generation unit. [11] The abnormality diagnosis apparatus according to claim 10, wherein the time series data comprises data obtained by performing four arithmetic operations and / or an integration operation and / or a differentiation operation and / or filtering on the first data and / or second data and / or third data. [12] Anomaly diagnostic procedure that includes: a command generation step of generating a command value for specifying the operation of an engine or a prime mover by an abnormality diagnosis device for performing a diagnosis of the operation of the engine or the prime mover driven by the engine; a drive control step of performing feedback control on the motor based on a control gain by the abnormality diagnosis device so that the operation of the motor or the prime mover follows the command value; a data switching step for switching selected time-series data through the abnormality diagnosis device by selecting data from time-series data indicating a state of the engine or the prime mover based on the result of a comparison between a control bandwidth determined from the control gain and a threshold value determined from the prime mover; and an abnormality determination step of determining an abnormal condition of the engine or the prime mover by the abnormality diagnosis device based on the selected time series data. [13] Anomaly diagnosis method according to claim 12, wherein in the data switching step, the anomaly diagnosis device selects the selected time series data to be output from a first data group of the time series data when the control bandwidth is higher than the threshold, and selects the selected time series data to be output from a second data group of the time series data when the control bandwidth is lower than the threshold, the first data group includes: a current command for driving the motor, a torque command for driving the motor or prime mover, an actual current detected at the motor, an actual torque detected at the motor or prime mover, a disturbance torque estimate which is an estimate of a disturbance torque at the motor or prime mover, a current deviation which is a difference between the current command and the actual current, and a torque deviation which is a difference between the torque command and the actual torque, and the second data group includes: an actual position of the motor or prime mover, a speed command for the motor or prime mover, an actual speed of the motor or prime mover, an acceleration of the motor or prime mover, a position deviation which is a difference between a position command corresponding to the motor or actual position and the actual position, and a speed deviation which is a difference between the speed command and the actual speed.

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