Abnormality determination system, abnormality determination device, and abnormality determination method

Abstract

An abnormality determination system, an abnormality determination device, and an abnormality determination method are provided, which can improve the accuracy of abnormality determination. The abnormality determination system (1) comprises: a first data acquisition unit (63) that acquires time series data related to the operation state of a drive device; a sample data creation unit (51) that creates sample data based on the time series data when an abnormality occurs in the operation of the drive device; and a first abnormality determination unit (65) that determines that the operation of the drive device is abnormal based on the time series data acquired by the first data acquisition unit (63) and the sample data.

Description

Technical Field

[0001] The disclosed embodiments relate to an abnormality determination system, an abnormality determination device, and an abnormality determination method. Background Art

[0002] Patent Document 1 describes an abnormality determination device for determining mechanical abnormalities in a motor drive mechanism. This device acquires multiple time-series data related to the motor's input and output during normal operation to create sample data, compares the current time-series data with the sample data, calculates the Mahalanobis distance, and determines abnormalities.

[0003] Patent Document 1: Japanese Patent Application Laid-Open No. 2017-151598

[0004] In an abnormality determination device, it is desired to improve the accuracy of abnormality determination. Summary of the Invention

[0005] The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an abnormality determination system, an abnormality determination device, and an abnormality determination method capable of improving the accuracy of abnormality determination.

[0006] In order to solve the above-mentioned problems, according to one aspect of the present invention, an abnormality determination system is applied, which determines that the operation of a drive device is abnormal, wherein the abnormality determination system comprises: a first data acquisition unit, which acquires time series data related to the operation state of the drive device; a sample data creation unit, which creates sample data based on the time series data when an abnormality occurs in the operation of the drive device; and a first abnormality determination unit, which determines that the operation of the drive device is abnormal based on the time series data and the sample data acquired by the first data acquisition unit.

[0007] In addition, according to another aspect of the present invention, an abnormality determination system is applied, which determines the abnormality of the release action of a brake used to brake a motor, wherein the abnormality determination system has: an action instruction output unit, which outputs an action instruction to the motor; a first data acquisition unit, which acquires time series data related to the state of the release action of the brake before outputting the action instruction to the motor; a first abnormality determination unit, which determines the abnormality of the release action of the brake based on the time series data before outputting the action instruction to the motor; a second data acquisition unit, which acquires state quantity data related to the action state of the motor after outputting the action instruction to the motor; and a second abnormality determination unit, which determines the abnormality of the release action of the brake based on the state quantity data after outputting the action instruction to the motor.

[0008] In addition, according to another aspect of the present invention, an abnormality determination system is applied, which determines the abnormality of the release action of a brake used to brake a motor, wherein the abnormality determination system has: an action instruction output unit, which outputs an action instruction for causing the motor to move; a data acquisition unit, which acquires state quantity data related to the action state of the motor after the action instruction output unit outputs the action instruction; and an abnormality determination unit, which determines the abnormality of the release action of the brake based on the state quantity data after the action instruction output unit outputs the action instruction.

[0009] In addition, according to another aspect of the present invention, an abnormality determination device is applied, which determines whether the operation of a drive device is abnormal, wherein the abnormality determination device has: a first data acquisition unit, which acquires time series data related to the operation state of the drive device; and a first abnormality determination unit, which determines whether the operation of the drive device is abnormal based on the time series data acquired by the first data acquisition unit and sample data created based on the time series data when an abnormality occurs in the operation of the drive device.

[0010] In addition, according to another aspect of the present invention, an abnormality determination device is applied, which determines the abnormality of the release action of the brake used to brake the motor, wherein the abnormality determination device has: a first data acquisition unit, which acquires time series data related to the state of the release action of the brake before outputting the action instruction to the motor; a first abnormality determination unit, which determines the abnormality of the release action of the brake based on the time series data before outputting the action instruction to the motor; a second data acquisition unit, which acquires state quantity data related to the action state of the motor after outputting the action instruction to the motor; and a second abnormality determination unit, which determines the abnormality of the release action of the brake based on the state quantity data after outputting the action instruction to the motor.

[0011] In addition, according to another aspect of the present invention, an abnormality determination method is applied to determine whether the operation of a drive device is abnormal, wherein the abnormality determination method comprises: obtaining time series data related to the operation state of the drive device; and determining whether the operation of the drive device is abnormal based on the obtained time series data and sample data created based on the time series data when an abnormality occurs in the operation of the drive device.

[0012] In addition, according to another aspect of the present invention, an abnormality determination method is applied, which determines the abnormality of the release action of a brake used to brake a motor, wherein the abnormality determination method has the following steps: before outputting an action instruction to the motor, obtaining time series data related to the state of the release action of the brake; before outputting the action instruction to the motor, determining the abnormality of the release action of the brake based on the time series data; after outputting the action instruction to the motor, obtaining state quantity data related to the action state of the motor; and after outputting the action instruction to the motor, determining the abnormality of the release action of the brake based on the state quantity data.

[0013] Effects of the Invention

[0014] According to the abnormality determination system and the like of the present invention, the accuracy of abnormality determination can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a diagram showing an example of the overall configuration of the abnormality determination system according to the embodiment.

[0016] Figure 2 This is a cross-sectional view showing an example of the structure of a motor, a brake, and an encoder.

[0017] Figure 3 This is a block diagram showing an example of the functional configuration of a host control device, a motor control device, and an engineering tool.

[0018] Figure 4 This is a diagram showing an example of sample data created by the sample data creation unit.

[0019] Figure 5 This is an explanatory diagram showing an example of an abnormality determination method of the first abnormality determination unit.

[0020] Figure 6 This is an explanatory diagram showing another example of the abnormality determination method of the first abnormality determination unit.

[0021] Figure 7 This is a diagram showing an example of an abnormality determination method using an estimated value of the moment of inertia by the second abnormality determination unit.

[0022] Figure 8 This is a graph showing an example of a waveform of an estimated value of the moment of inertia.

[0023] Figure 9 : is a graph showing another example of the waveform of the estimated value of the moment of inertia.

[0024] Figure 10 This is a diagram showing an example of an abnormality determination method using a disturbance torque estimated value by the second abnormality determination unit.

[0025] Figure 11 : is a graph showing an example of a waveform of a disturbance torque estimated value.

[0026] Figure 12 : is a graph showing another example of the waveform of the disturbance torque estimated value.

[0027] Figure 13 This is a flowchart showing an example of a processing procedure executed by the host control device and the motor control device.

[0028] Figure 14 This is a block diagram showing an example of the hardware configuration of a motor control device.

[0029] Label Description

[0030] 1: Abnormality determination system

[0031] 5: Motor control device (abnormality determination device)

[0032] 9: Brake (drive device)

[0033] 13: Accelerometer

[0034] 51: Sample data creation department

[0035] 53: Motor command output unit (action command output unit)

[0036] 55: Brake command output unit (release command output unit)

[0037] 63: First data acquisition unit

[0038] 65: First Abnormality Judgment Unit

[0039] 67: Inertia moment estimation unit

[0040] 69: Disturbance torque estimation unit

[0041] 71: Second data acquisition unit

[0042] 73: Second Abnormality Judgment Unit

[0043] 75: Mahalanobis distance calculation unit

[0044] 77: Judgment Department DETAILED DESCRIPTION

[0045] Hereinafter, embodiments will be described with reference to the drawings.

[0046] <1. Overall Structure of the Abnormality Judgment System>

[0047] Reference Figure 1An example of the overall structure of an abnormality determination system 1 according to this embodiment will be described. The abnormality determination system 1 is a system for determining abnormalities in the operation of a drive device. In this embodiment, the abnormality determination system 1 will be described as determining an abnormality in, for example, the release of a brake for braking a motor.

[0048] like Figure 1 As shown, the abnormality determination system 1 includes a host control device 3 , a motor control device 5 , a motor 7 , a brake 9 , an encoder 11 , an acceleration sensor 13 , and an engineering tool 15 .

[0049] The host control device 3 is composed of a computer such as a general-purpose personal computer, a PLC (Programmable Logic Controller), or a motion controller. The host control device 3 generates motor commands (e.g., position commands, speed commands, torque commands, etc.) for controlling the operation of the motor 7 and transmits them to the motor control device 5. Furthermore, the host control device 3 generates brake commands for applying or releasing the brake 9 and transmits them to the motor control device 5.

[0050] The motor control device 5 supplies power to the motor 7 based on motor commands received from the host control device 3 and detection data received from the encoder 11, thereby controlling the operation of the motor 7. Furthermore, the motor control device 5 supplies power to or cuts off power to the brake 9 based on brake commands received from the host control device 3, thereby controlling the operation of the brake 9. Furthermore, the motor control device 5 determines abnormalities in the release operation of the brake 9 based on time-series data obtained from the acceleration sensor 13 and sample data created by the engineering tool 15. The motor control device 5 is also referred to as a servo amplifier.

[0051] The motor 7 is, for example, a rotary motor. In addition, the type of motor 7 is not limited to a rotary motor, and may also be a direct-acting motor (linear motor). The brake 9 brakes the motor 7 and releases the brake. In this embodiment, the situation where the brake 9 brakes the motor 7 is referred to as "working", and the situation where the brake of the motor 7 is released is referred to as "releasing". The encoder 11 detects the rotational position, rotational speed, etc. of the motor 7, and sends the detection data to the motor control device 5. The acceleration sensor 13 detects the vibration caused by the release action of the brake 9, and sends the detection data to the motor control device 5 or the engineering tool 15. The acceleration sensor 13 is, for example, provided at the encoder 11. In addition, the location where the acceleration sensor 13 is set is not limited to the encoder 11, and may, for example, be provided at the motor 7 or the brake 9.

[0052] The engineering tool 15 is, for example, a general-purpose personal computer. Alternatively, it may be a dedicated computer designed for a specific purpose (e.g., creating sample data). The engineering tool 15 creates sample data based on the time-series data received from the acceleration sensor 13. The sample data created by the engineering tool 15 is sent to the motor control device 5 and recorded.

[0053] In addition, the structure of the abnormality determination system 1 described above is an example and is not limited to the above content. For example, the function of determining whether the release action of the brake 9 is abnormal can be installed in the upper control device 3 or the engineering tool 15 instead of the motor control device 5, or it can be installed in an abnormality determination device that is separate from these control devices. In this case, it is sufficient to obtain the data required for abnormality determination from the motor control device 5. In addition, the function of controlling the brake 9 can be installed in the upper control device 3 or the engineering tool 15 instead of the motor control device 5, or it can be installed in a brake control device that is separate from these control devices. In addition, the functions of the upper control device 3, the motor control device 5 and the engineering tool 15 can be configured as fewer devices (for example, a single unit or two control devices), or as more devices (for example, four or more control devices).

[0054] <2.Structure of motor, brake, and encoder>

[0055] Reference Figure 2 , an example of the structure of the motor 7, the brake 9 and the encoder 11 is described. In addition, hereinafter, "load side" refers to the direction in which the load is installed on the motor 7, for example, the direction in which the shaft 17 protrudes ( Figure 2 The “opposite side to the load” refers to the opposite direction to the load side ( Figure 2 center right).

[0056] like Figure 2 As shown, the motor 7 includes a shaft 17, a rotor 19, a stator 21, a load-side bracket 23, a load-side bearing 25, an opposite-load-side bracket 27, and an opposite-load-side bearing 29. The shaft 17 is supported rotatably about the axis AX by the load-side bearing 25 and the opposite-load-side bearing 29. The opposite-load side of the shaft 17 protrudes from the opposite-load-side bracket 27, and the brake 9 and the encoder 11 are provided on the protruding portion.

[0057] The brake 9 (an example of a drive device) is, for example, a non-excitation type brake, which operates when the brake power is not supplied to brake the shaft 17 of the motor 7 so as to prevent the motor 7 from rotating, and releases the motor 7 when the brake power is supplied to allow the shaft 17 to rotate. In addition, the type of brake 9 is not limited to the non-excitation type, and may also be an excitation type, for example.

[0058] The brake 9 includes a field core 31 , an armature 33 , a brake disc 35 , and a fixing plate 37 .

[0059] The field core 31 includes a brake coil 39 and a spring 41. The coil end 43 of the brake coil 39 is electrically connected to the motor control device 5. The armature 33 is supported so as to be non-rotatable relative to the field core 31 and to be movable in the axial direction of the shaft 17. The brake disc 35 is supported via a hub 44 so as to be non-rotatable relative to the shaft 17 and to be movable in the axial direction. The brake disc 35 has friction members 45 on its load-side surface and on its opposite-to-load-side surface. The fixing plate 37 is fixed to the opposite-to-load-side bracket 27, etc.

[0060] When the brake coil 39 is not energized (non-excitation state), the armature 33 is pressed toward the load side by the spring 41, so that the friction member 45 of the brake disc 35 is clamped by the armature 33 and the fixed plate 37. As a result, when the brake power supply is not supplied, the shaft 17 is kept from rotating. This state is the working state of the brake 9. On the other hand, when the brake coil 39 is energized (excitation state), the armature 33 is attracted to the side opposite to the load by the magnetic attraction force of the brake coil 39, and the brake disc 35 is released. As a result, the shaft 17 can rotate. This state is the released state of the brake 9.

[0061] The encoder 11 includes an encoder body 47, an encoder cover 49, and the aforementioned acceleration sensor 13. The encoder body 47 includes, for example, a disk (not shown) that rotates together with the shaft 17, and a substrate (not shown) on which a detection circuit for detecting a pattern formed on the disk is mounted. The encoder cover 49 is fixed to the brake 9 and houses the encoder body 47. The acceleration sensor 13 is, for example, located inside the encoder cover 49. Alternatively, the acceleration sensor 13 may be located within the encoder body 47 (e.g., by mounting it on a substrate).

[0062] The configuration of the motor 7, brake 9, and encoder 11 described above is merely an example and is not intended to be limiting. For example, the encoder 11 may be positioned between the motor 7 and the brake 9, or at least one of the brake 9 and the encoder 11 may be positioned on the load side of the motor 7. Furthermore, the acceleration sensor 13 may be positioned, for example, outside the encoder cover 49, or inside or outside the motor 7 or brake 9.

[0063] <3. Functional Structure of Host Control Device, Motor Control Device, and Engineering Tools>

[0064] Reference Figures 3 to 12 , an example of the functional structure of the host control device 3, the motor control device 5, and the engineering tool 15 is described.

[0065] like Figure 3As shown, the engineering tool 15 includes a sample data creating unit 51. The sample data creating unit 51 creates sample data based on time series data when an abnormality occurs in the release operation of the brake 9 (an example of time series data when an abnormality occurs in the operation of the drive device).

[0066] Figure 4 An example of sample data created by the sample data creating unit 51 is shown. Figure 4 As shown, the sample data creation unit 51 repeatedly acquires time-series data from the acceleration sensor 13 when an abnormality occurs during the release operation of the brake 9, generating multiple sample data sets. Specifically, assuming the brake 9 is in an abnormal state (e.g., mechanically inoperative), the brake control unit 59 of the motor control device 5 receives a release command from the brake command output unit 55 of the host control device 3 and supplies power to the brake 9 multiple times (e.g., several to several dozen times). This brake power supply is performed while the motor command output unit 53 of the host control device 3 is not outputting a motor command. The sample data creation unit 51 acquires time-series data each time and extracts a predetermined period to create multiple sample data sets. "Time-series data" refers to data obtained by arranging multiple detection data sets from the acceleration sensor 13 in a time-series manner. Furthermore, "predetermined period" refers to a predetermined length of time before and after the timing (hereinafter referred to as "release timing") at which the brake control unit 59 of the motor control device 5 receives a release command from the brake command output unit 55 of the host control device 3 and supplies power to the brake 9. Furthermore, "a situation in which an abnormality occurs during the release of the brake 9" refers to a situation in which the brake 9 does not operate despite power being supplied. During the release of the brake 9, since the brake 9 does not operate during an abnormality and vibration is not detected, the time series data detected by the acceleration sensor 13 exhibits minimal variation, and the variations between the multiple time series data are also small. The multiple sample data created by the sample data creation unit 51 are transmitted to the motor control device 5 and recorded.

[0067] Furthermore, the sample data creation unit 51 calculates the sample mean μ and the sample covariance matrix Σ from the created sample data group based on the following equations, for example. (n) is the nth sample data.

[0068]

[0069]

[0070] In addition, the sample data creation unit 51 calculates the data abnormality determination threshold value a based on the following formula according to the false alarm rate α and the chi-square distribution: th .

[0071]

[0072] The false alarm rate α is an indicator used to determine how much deviation from the normal distribution is considered abnormal data. The chi-square distribution is defined by the following equation. The degrees of freedom M is a parameter that specifies the number of independent sample data types (the number of variable types). In this embodiment, M = 1.

[0073]

[0074] Where Γ represents the gamma function, which is defined as follows.

[0075]

[0076] The sample mean μ, the sample covariance matrix Σ, and the data abnormality determination threshold a calculated by the sample data creation unit 51 are th It is sent to the motor control device 5 and recorded.

[0077] return Figure 3 The upper control device 3 includes a motor command output unit 53 and a brake command output unit 55. The motor command output unit 53 (an example of an action command output unit) generates a motor command (an example of an action command, such as a position command, a speed command, a torque command, etc.) for controlling the action of the motor 7 and sends it to the motor control unit 57 of the motor control device 5. The brake command output unit 55 (an example of a release command output unit) generates an action command for operating the brake 9 or a release command for releasing the brake 9 and sends it to the brake control unit 59 of the motor control device 5.

[0078] The motor control device 5 (an example of an abnormality determination device) has a motor control unit 57, a brake control unit 59, a recording unit 61, a first data acquisition unit 63, a first abnormality determination unit 65, an inertia moment estimation unit 67, an interference torque estimation unit 69, a second data acquisition unit 71 and a second abnormality determination unit 73.

[0079] The motor control unit 57 supplies power to the motor 7 and controls the motor 7 based on the motor command received from the motor command output unit 53 of the host control device 3 and the detection data received from the encoder 11. Specifically, the motor control unit 57 includes, for example, a position control unit, a speed control unit, and a current control unit (not shown). For example, when a position command is received from the host control device 3, the position control unit generates a speed command through, for example, PID control, based on the position deviation obtained by subtracting the feedback position based on the detection data of the encoder 11 from the position command. The speed control unit generates a torque command through, for example, PID control, based on the speed deviation obtained by subtracting the feedback speed based on the detection data of the encoder 11 from the speed command. The current control unit performs power conversion based on the torque command and supplies power to the motor 7.

[0080] The brake control unit 59 controls the brake 9 by supplying or cutting off power to the brake 9 based on brake commands received from the brake command output unit 55 of the host control device 3. Specifically, the brake control unit 59 includes, for example, a brake power supply unit (not shown) for supplying power to the brake 9, and a relay (not shown) having contacts for supplying or cutting off power from the brake power supply unit. Upon receiving a release command from the host control device 3 to release the brake 9, the brake control unit 59 closes the relay contacts, supplying power to the brake 9. On the other hand, upon receiving an operation command from the host control device 3 to activate the brake 9, the brake control unit 59 opens the relay contacts, cutting off power to the brake 9.

[0081] The recording unit 61 is composed of, for example, a nonvolatile memory, a hard disk, etc. The recording unit 61 receives and records the sample data created by the sample data creation unit 51 of the engineering tool 15, the calculated sample mean μ, the sample covariance matrix Σ, and the data abnormality determination threshold a. th wait.

[0082] The first data acquisition unit 63 acquires time-series data related to the state of the release operation of the brake 9 (an example of time-series data related to the operating state of the drive device). The type of time-series data is not particularly limited, as long as it indicates whether the release operation of the brake 9 has been performed normally. However, in this embodiment, for example, time-series data is acquired from the acceleration sensor 13 that detects vibration caused by the release operation of the brake 9. The first data acquisition unit 63 acquires time-series data for the predetermined period before and after the release timing, including the above-mentioned release timing, before the motor command output unit 53 of the host control device 3 outputs a motor command (when no motor command is output).

[0083] The first abnormality determination unit 65 determines the abnormality of the release action of the brake 9 (an example of an abnormality in the action of the drive device) based on the time series data obtained by the first data acquisition unit 63 and the sample data read from the recording unit 61. The first abnormality determination unit 65 determines the abnormality of the release action of the brake 9 before the motor instruction output unit 53 of the upper control device 3 outputs the motor instruction (in the state where the motor instruction is not output). The method for determining the abnormality is not particularly limited. In this embodiment, for example, the Mahalanobis distance is used for determination. The first abnormality determination unit 65 has a Mahalanobis distance calculation unit 75 and a determination unit 77. The Mahalanobis distance calculation unit 75 calculates the Mahalanobis distance based on the sample data and the time series data. The determination unit 77 determines the abnormality of the release action of the brake 9 by comparing the calculated Mahalanobis distance with the threshold value. As described above, the sample data is created based on the time series data when the release action of the brake 9 produces an abnormality. Therefore, the judgment unit 77 compares the current time series data with the sample data, and judges it as normal when the number of points whose Mahalanobis distance is above the threshold is greater than the specified value (when the deviation between the time series data and the sample data is large), and judges it as abnormal when the number of points whose Mahalanobis distance is above the threshold is less than the specified value (when the deviation between the time series data and the sample data is small).

[0084] Specifically, the Mahalanobis distance calculation unit 75 calculates the Mahalanobis distance a(x′) using the following equation based on the sample mean μ and the sample covariance matrix Σ read from the recording unit 61 and the time series data acquired by the first data acquisition unit 63 .

[0085]

[0086] The determination unit 77 reads the data abnormality determination threshold value a from the recording unit 61. th The Mahalanobis distance a(x') is compared with the Mahalanobis distance a(x') calculated by the Mahalanobis distance calculation unit 75. When the Mahalanobis distance a(x') is the data abnormality determination threshold a th If the number of points above is greater than the specified value, it is judged to be normal. The Mahalanobis distance a(x') is the data abnormality judgment threshold a. th If the above number of points is less than the specified value, it is judged as abnormal.

[0087] Figure 5 and Figure 6 FIG. 6 shows an example of abnormality determination performed by the first abnormality determination unit 65. Figure 5As shown, when the release action of the brake 9 is normal, the time series data detected by the acceleration sensor 13 varies greatly in the release timing, and the deviation between the multiple time series data (such as the deviation in amplitude, etc.) is also large. Therefore, assuming that a plurality of normal time series data are obtained to create sample data, the current time series data is compared with the sample data and the Mahalanobis distance is calculated to determine the abnormality, even if the release action is normal, the Mahalanobis distance becomes large, and the abnormality may not be detected correctly. In this embodiment, as described above, a plurality of abnormal time series data with small deviations are obtained to create sample data, and the current time series data is compared with the sample data to calculate the Mahalanobis distance. Thus, as Figure 5 As shown, when the release action of the brake 9 is normal, the number of points where the Mahalanobis distance exceeds the threshold value increases. Therefore, by determining that the operation is normal when this number of points is greater than (or greater than) a predetermined value, accurate abnormality determination can be made even when the time series data during normal operation exhibits significant deviations. The predetermined value is the threshold value for the number of points where the Mahalanobis distance exceeds the threshold value, which is used to determine that the release action of the brake 9 is abnormal.

[0088] On the other hand, Figure 6 As shown, when the release action of the brake 9 is abnormal, the change in the time series data detected by the acceleration sensor 13 is small, and the deviation between the multiple time series data is also small. Therefore, the number of points with a Mahalanobis distance above the threshold decreases, and when this number of points is less than the specified value (or below the specified value), it is determined to be abnormal, thereby enabling accurate abnormality determination.

[0089] return Figure 3 The inertia moment estimation unit 67 estimates the inertia moment of the motor 7 based on the torque command generated by the speed control unit of the motor control unit 57 and the feedback acceleration based on the detection data of the encoder 11.

[0090] The disturbance torque estimation unit 69 estimates the disturbance torque applied to the motor 7 based on the torque command generated by the speed control unit of the motor control unit 57 and the feedback speed based on the detection data of the encoder 11 .

[0091] The second data acquisition unit 71 acquires state quantity data related to the operating state of the motor 7. The type of "state quantity data" is not particularly limited, as long as it represents the operating state of the motor 7. However, in this embodiment, the second data acquisition unit 71 acquires the estimated value of the moment of inertia estimated by the moment of inertia estimation unit 67, the estimated value of the disturbance torque estimated by the disturbance torque estimation unit 69, and the torque command value generated by the speed control unit of the motor control unit 57. The second data acquisition unit 71 acquires each of these state quantity data after the motor command output unit 53 of the host control device 3 outputs a motor command (including the timing of outputting the motor command). For example, after the brake command output unit 55 of the host control device 3 outputs a release command and the brake control unit 59 of the motor control device 5 supplies power to the brake 9, the second data acquisition unit 71 acquires each of these state quantity data at the time when the motor command output unit 53 first outputs the motor command (the time when the motor control unit 57 of the motor control device 5 supplies power to the motor 7).

[0092] The second abnormality determination unit 73 determines an abnormality in the release operation of the brake 9 based on the state quantity data (e.g., estimated value of the moment of inertia, estimated value of the disturbance torque, torque command value, etc.) acquired by the second data acquisition unit 71. The second abnormality determination unit 73 determines an abnormality after the motor command output unit 53 of the host control device 3 outputs the motor command (including the timing of outputting the motor command). For example, after the brake command output unit 55 of the host control device 3 outputs the release command and the brake control unit 59 of the motor control device 5 supplies power to the brake 9, the second abnormality determination unit 73 determines an abnormality at the time when the motor command output unit 53 first outputs the motor command (the time when the motor control unit 57 of the motor control device 5 supplies power to the motor 7).

[0093] Figures 7 to 9 FIG. 7 shows an example of abnormality determination using the estimated value of the moment of inertia by the second abnormality determination unit 73. When there is an abnormality in the release action of the brake 9, the motor 7 is braked even after the release command is output (power is supplied to the brake 9). Therefore, Figure 8 and Figure 9 As shown in FIG. 1 , at the time when the motor command is first output after the brake is released (the time when power is supplied to the motor 7), the estimated value of the inertia moment of the motor 7 becomes an abnormally large value compared to the normal state. Figure 7 As shown, the second abnormality determination circuit 73 determines that the estimated value of the moment of inertia is normal when it is less than the threshold value (or when it is below the threshold value), and determines that the estimated value of the moment of inertia is abnormal when it is greater than the threshold value (or when it is above the threshold value). This makes it possible to perform accurate abnormality determination.

[0094] Figures 10 to 12FIG. 7 shows an example of abnormality determination using the estimated value of the disturbance torque by the second abnormality determination unit 73. When there is an abnormality in the release operation of the brake 9, the motor 7 is braked even after the release command is output (power is supplied to the brake 9). Therefore, Figure 11 and Figure 12 As shown in FIG. 1 , at the moment when the motor command is first output after the brake is released (the moment when power is supplied to the motor 7), the disturbance torque estimation value of the motor 7 becomes an abnormally large value compared to the normal state and is substantially equal to the torque command value. Figure 10 As shown, the second abnormality determination unit 73 determines that the system is normal when the estimated value of the disturbance torque is less than a threshold value (or is below the threshold value), and determines that the system is abnormal when the estimated value of the disturbance torque is greater than a threshold value (or is above the threshold value) and the estimated value of the disturbance torque is substantially equal to the torque command value. This enables accurate abnormality determination.

[0095] Furthermore, the sharing of processing among the various devices described above is not limited to the above example. For example, a portion or all of the processing in the motor control device 5 may be implemented in the host control device 3 or the engineering tool 15. Alternatively, a portion or all of the processing in the host control device 3 may be implemented in the motor control device 5 or the engineering tool 15. Alternatively, a portion or all of the processing in the engineering tool 15 may be implemented in the host control device 3 or the motor control device 5.

[0096] In addition, the sample average μ, sample covariance matrix Σ, and data abnormality determination threshold a, which are relatively heavy in processing, are processed by the engineering tool 15. th The calculation of the Mahalanobis distance and the result of the calculation are recorded in the motor control device 5. The motor control device 5 performs the calculation of the Mahalanobis distance and the abnormality determination, which have a relatively low processing load, thereby reducing the processing load of the motor control device 5. However, this is not limited to this. For example, all of the above processing can be performed by any one of the motor control device 5, the host control device 3, and the engineering tool 15, or can be performed by two or more devices in a different sharing mode than described above.

[0097] In addition, the processing in the motor instruction output unit 53 and the brake instruction output unit 55 of the above-mentioned upper control device 3, the processing in the first data acquisition unit 63, the first abnormality judgment unit 65, the inertia moment estimation unit 67, the interference torque estimation unit 69, the second data acquisition unit 71 and the second abnormality judgment unit 73 of the motor control device 5, and the processing in the sample data creation unit 51 of the engineering tool 15 are not limited to the examples of sharing of these processing. For example, the processing can be performed by a smaller number of processing units (for example, one processing unit), or by further subdivided processing units. In addition, the motor control device 5 can also be installed only in the part that supplies power to the motor 7 and the brake 9 through an actual device, and the functions of the other above-mentioned processing units are performed by the CPU 901 (refer to Figure 14 ) is installed by a program executed by the computer, and part or all of the function can also be installed through actual devices such as ASIC, FPGA, other circuits, etc.

[0098] <4. Processing steps of the upper control device and the motor control device>

[0099] Reference Figure 13 An example of a processing procedure (abnormality determination method) executed by the host control device 3 and the motor control device 5 will be described. At the start time of this flowchart, the brake 9 is in an actuated state.

[0100] In step S5 , the motor control device 5 starts acquiring the time-series data from the acceleration sensor 13 via the first data acquisition unit 63 .

[0101] In step S10, the host control device 3 outputs a release command via the brake command output unit 55, and the motor control device 5 supplies power to the brake 9 via the brake control unit 59. Thus, the brake 9 is released under normal circumstances, and remains in an engaged state under abnormal circumstances.

[0102] In step S15 , the motor control device 5 completes the acquisition of the time-series data from the acceleration sensor 13 by the first data acquisition unit 63 .

[0103] In step S20 , the host control device 3 outputs an operation command via the brake command output unit 55 , and the motor control device 5 stops the power supply to the brake 9 via the brake control unit 59 to operate the brake 9 .

[0104] In step S25, the motor control device 5 reads the sample data and various calculation results (sample mean μ, sample covariance matrix Σ, data abnormality determination threshold a) recorded in the recording unit 61 through the first abnormality determination unit 65. th wait).

[0105] In step S30 , the motor control device 5 uses the first abnormality determination unit 65 to determine whether the release operation of the brake 9 is normal or abnormal based on the time series data acquired in steps S5 to S15 and the sample data read in step S25 .

[0106] In step S35, the motor control device 5 determines whether the result of the determination in step S30 is normal. If normal (step S35: Yes), the process proceeds to the next step S40. If abnormal (step S35: No), the process proceeds to step S70 described later.

[0107] In step S40, the host control device 3 outputs a release command via the brake command output unit 55, and the motor control device 5 supplies power to the brake 9 via the brake control unit 59. Thus, the brake 9 is released under normal circumstances, and remains in an engaged state under abnormal circumstances.

[0108] In step S45, the host control device 3 outputs a motor command via the motor command output unit 53, and the motor control device 5 supplies power to the motor 7 via the motor control unit 57. Thus, if the brake 9 is normally released, the motor 7 starts to operate, and if the brake 9 is abnormal, the motor 7 is braked and does not operate.

[0109] In step S50, the motor control device 5 acquires state quantity data related to the operating state of the motor 7 via the second data acquisition unit 71. As described above, the state quantity data includes estimated values of the inertia moment, estimated values of the disturbance torque, and torque command values.

[0110] In step S55 , the motor control device 5 determines whether the release operation of the brake 9 is normal or abnormal based on the state quantity data acquired in step S50 , using the second abnormality determination unit 73 .

[0111] In step S60, the motor control device 5 determines whether the result of the determination in step S55 is normal. If normal (step S60: Yes), the process proceeds to step S65, where the normal processing configured for normal determinations is executed. This normal processing includes, for example, transmitting the normal determination result to the host control device 3 or engineering tool 15, terminating the abnormality determination process, and resuming normal operation (actual operation).

[0112] On the other hand, in step S60, if the result of the determination in step S55 is abnormal (step S60: No), the process proceeds to step S70, where the abnormality processing set for abnormality is executed. This abnormality processing includes, for example, outputting an alarm, transmitting the abnormality determination result to the host control device 3 or the engineering tool 15, and stopping normal operation (actual operation). This flowchart ends with the above steps.

[0113] According to the above-mentioned processing steps, before the motor command is output in step S45, the abnormality of the release action of the brake 9 is determined in step S30. Thus, the abnormality can be determined before the motor 7 is actuated, and thus the abnormality can be determined without applying a load to the brake 9. In addition, since it is not affected by the mechanical side other than the brake, the abnormality can be determined with high precision. In addition, after the motor command is output in step S45, the abnormality of the release action of the brake 9 is also determined in step S55. Thus, the abnormality determination based on the two stages before and after the motor 7 is actuated can be performed, so the accuracy and reliability of the abnormality determination can be improved. In addition, when the results of each abnormality determination are different, it can be detected that any abnormality determination function itself has generated an abnormality.

[0114] The processing steps described above are merely examples, and at least a portion of the steps may be deleted or modified, or additional steps may be added. The order of at least a portion of the steps may be changed, or multiple steps may be combined into a single step.

[0115] <5. Effects of Implementation>

[0116] As described above, the abnormality determination system 1 of this embodiment includes: a first data acquisition unit 63, which acquires time series data related to the operation state of the driving device; a sample data creation unit 51, which creates sample data based on the time series data when an abnormality occurs in the operation of the driving device; and a first abnormality determination unit 65, which determines the operation abnormality of the driving device based on the time series data acquired by the first data acquisition unit 63 and the sample data created by the sample data creation unit 51.

[0117] In addition, the motor control device 5 of this embodiment has: a first data acquisition unit 63, which acquires time series data related to the operation state of the drive device; and a first abnormality judgment unit 65, which judges whether the operation of the drive device is abnormal based on the time series data acquired by the first data acquisition unit 63 and sample data created based on the time series data when an abnormality occurs in the operation of the drive device.

[0118] Typically, systems for detecting drive unit anomalies create sample data based on normal time-series data and compare the current time-series data with the sample data to determine anomalies. In this case, if the normal time-series data exhibits significant deviations, it may be impossible to accurately detect anomalies.

[0119] In this embodiment, abnormality determination is performed using sample data created based on time-series data from when an abnormality occurs in the operation of the drive device. The current time-series data is compared with the sample data, and if the deviation between the two data exceeds a specified amount, the condition is determined to be normal; if the deviation is less than the specified amount, the condition is determined to be abnormal. This allows accurate abnormality determination even when the deviation in the time-series data during normal operation is large, even if the deviation in the time-series data during an abnormality is small. This improves the accuracy of abnormality determination.

[0120] In this embodiment, the first abnormality determination unit 65 may also include a Mahalanobis distance calculation unit 75 that calculates the Mahalanobis distance based on the sample data and the time series data, and a determination unit 77 that determines whether the drive device is operating abnormally by comparing the Mahalanobis distance with a threshold value. In this case, the calculations related to abnormality determination can be simplified, reducing the processing load and enabling highly accurate abnormality determination.

[0121] In this embodiment, the first data acquisition unit 63 may acquire time series data related to the state of the release action of the brake 9 for braking the motor 7, and the first abnormality judgment unit 65 may judge the abnormality of the release action of the brake 9 based on the time series data acquired by the first data acquisition unit 63 and sample data created based on the time series data when an abnormality occurs in the release action of the brake 9.

[0122] During the release operation of the brake 9, the brake 9 does not operate during abnormal conditions, so the time series data has a small deviation. On the other hand, during normal conditions, the brake 9 is released, but the deviation can sometimes be large depending on the type of time series data acquired. Therefore, by using sample data created based on time series data from when the release operation of the brake 9 produces an abnormality, accurate abnormality determination can be made.

[0123] Furthermore, when using the braking current or voltage to determine an abnormality in the release operation of the brake 9, for example, a detection circuit must be installed outside or inside the motor control device 5, which increases costs. However, according to this embodiment, abnormalities are determined based on time series data and sample data, eliminating the need for a detection circuit and enabling abnormality determination without increasing costs.

[0124] Furthermore, in this embodiment, sample data is created based on time-series data from a situation where an abnormality occurs during the release of the brake 9 (a state where neither the brake 9 nor the motor 7 is actuated). Therefore, the sample data is not affected by the workpiece or operating mode. Therefore, even if the workpiece or operating mode is changed, accurate abnormality determination can be made without recreating sample data.

[0125] In this embodiment, the abnormality judgment system 1 may also have a motor instruction output unit 53 that outputs a motor instruction for moving the motor 7. In this case, the first data acquisition unit 63 may also acquire time series data before the motor instruction output unit 53 outputs the motor instruction, and the first abnormality judgment unit 65 may also judge the abnormality of the release action of the brake 9 based on the time series data and the sample data before the motor instruction output unit 53 outputs the motor instruction.

[0126] For example, if the motor 7 is operated while being braked by the brake 9 and the torque command and rotation angle are detected to determine an abnormality, a load is applied to the brake 9, which may affect the life of the brake 9. In addition, due to the influence of mechanical factors other than the brake, it is not always possible to diagnose only the brake 9.

[0127] In this embodiment, an abnormality in the release operation of the brake 9 is determined before the motor command output unit 53 outputs the motor command. This allows abnormality detection of the brake 9 without the motor 7 being actuated, thus enabling detection of abnormality without applying a load to the brake 9. Furthermore, since the system is not affected by mechanical factors other than the brake, abnormality detection can be performed with high accuracy.

[0128] In this embodiment, the abnormality judgment system 1 may also have: a second data acquisition unit 71, which acquires state quantity data related to the operation state of the motor 7 after the motor instruction output unit 53 outputs the motor instruction; and a second abnormality judgment unit 73, which judges the abnormality of the release action of the brake 9 based on the state quantity data after the motor instruction output unit 53 outputs the motor instruction.

[0129] In this case, the abnormality determination can be performed based on the two stages before and after the operation of the motor 7, thereby improving the accuracy and reliability of the abnormality determination. In addition, when the results of each abnormality determination are different, it can be detected that any abnormality determination function itself has an abnormality.

[0130] In the present embodiment, the first data acquisition unit 63 may acquire time-series data from the acceleration sensor 13 that detects vibration caused by the release operation of the brake 9 .

[0131] In this case, the brake 9 does not operate during an abnormality and no vibration is detected. Therefore, the change in the time series data is small, and the deviation between multiple time series data is small. Therefore, by using sample data created based on this time series data to perform abnormality determination, accurate abnormality determination can be performed.

[0132] In this embodiment, the abnormality judgment system 1 may also have: a brake command output unit 55, which outputs a release command for releasing the brake 9; and an inertia moment estimation unit 67 for estimating the inertia moment of the motor 7. In this case, the second data acquisition unit 71 may also obtain the estimated value of the inertia moment at the moment when the motor command output unit 53 initially outputs the motor command after the brake command output unit 55 outputs the release command as state quantity data, and the second abnormality judgment unit 73 judges the abnormality of the release action of the brake 9 based on the estimated value of the inertia moment.

[0133] If there is an abnormality in the release operation of the brake 9, the motor 7 remains in the braked state even after the brake command output unit 55 outputs the release command. Therefore, the estimated value of the inertia moment of the motor 7 becomes abnormally large at the time the motor command output unit 53 outputs the motor command. In this embodiment, an abnormality in the release operation of the brake 9 is determined based on the estimated value of the inertia moment of the motor 7. For example, if the estimated value of the inertia moment is greater than a threshold value, it can be determined as an abnormality. This allows for accurate abnormality determination.

[0134] In this embodiment, the abnormality judgment system 1 may also have: a brake command output unit 55, which outputs a release command for releasing the brake 9; and an interference torque estimation unit 69 for estimating the interference torque of the motor 7. In this case, the second data acquisition unit 71 may also obtain an estimated value of the interference torque at the moment when the motor command output unit 53 initially outputs the motor command after the brake command output unit 55 outputs the release command as state quantity data, and the second abnormality judgment unit 73 judges the abnormality of the release action of the brake 9 based on the estimated value of the interference torque.

[0135] If there is an abnormality in the release operation of the brake 9, the motor 7 remains in the braked state even after the brake command output unit 55 outputs the release command. Therefore, at the moment the motor command output unit 53 outputs the motor command, the estimated value of the disturbance torque of the motor 7 becomes abnormally large and approximately equal to the torque command. In this embodiment, an abnormality in the release operation of the brake 9 is determined based on the estimated value of the disturbance torque of the motor 7. For example, if the estimated value of the disturbance torque exceeds a threshold, an abnormality can be determined. This allows for accurate abnormality determination.

[0136] <6. Modifications>

[0137] The disclosed embodiments are not limited to the above-described ones, and various modifications can be made without departing from the spirit and technical concept thereof.

[0138] In the aforementioned embodiment, the first anomaly determination unit 65 calculates the Mahalanobis distance to determine anomalies. However, the anomaly determination method is not limited to the aforementioned method. For example, anomalies can also be determined using statistical methods such as the normal distribution. In this case, for example, a normal distribution can be created based on the sample data set, and a data anomaly determination threshold can be set for the normal distribution. If the current time series data exceeds the data anomaly determination threshold set for the normal distribution, the data is determined to be abnormal.

[0139] In addition, the aforementioned embodiment describes an example in which the abnormality determination system is applied to determine abnormalities in the release operation of a brake, which is used to brake a motor. However, the objects for abnormality determination are not limited to the aforementioned. The aforementioned abnormality determination system can be applied to determine abnormalities in the operation of various drive devices other than brakes. In particular, the aforementioned abnormality determination system is preferred when the deviation of the time series data related to the operating status of the drive device is large when the drive device is normal, and when the deviation of the time series data related to the operating status is small when the drive device is abnormal.

[0140] <7. Example of Hardware Configuration of Motor Control Device>

[0141] Reference Figure 14 , the hardware structure example of the motor control device 5 is described. Figure 14 In the figure, the configuration of the motor control device 5 related to the function of supplying power to the motor 7 or the brake 9 is omitted as appropriate. In addition, the host control device 3 and the engineering tool 15 may be configured as the same hardware configuration.

[0142] like Figure 14 As shown, the motor control device 5 includes, for example, a CPU 901, a ROM 903, a RAM 905, a dedicated integrated circuit 907 such as an ASIC or FPGA configured for a specific purpose, an input device 913, an output device 915, a recording device 917, a driver 919, a connection port 921, and a communication device 923. These components are connected via a bus 909 and an input / output interface 911 so as to be able to transmit signals to each other.

[0143] The program can be recorded in, for example, the ROM 903 , the RAM 905 , or a recording device 917 such as a hard disk.

[0144] The program can also be temporarily or non-temporarily (permanently) recorded on a removable recording medium 925 such as a floppy disk, various CD / MO disks / DVDs, or a semiconductor memory. Such a recording medium 925 can also be provided as so-called packaged software. In this case, the program recorded on the recording medium 925 can also be read by the drive 919 and recorded in the recording device 917 via the input / output interface 911 or the bus 909.

[0145] The program can also be recorded in a download site, another computer, or another recording device (not shown). In this case, the program is transmitted via a network NW such as a LAN or the Internet, and the communication device 923 receives the program. The program received by the communication device 923 can also be recorded in the recording device 917 via the input / output interface 911 or the bus 909.

[0146] The program can also be recorded in, for example, an appropriate external connection device 927. In this case, the program can be transferred via an appropriate connection port 921 and recorded in the recording device 917 via the input / output interface 911 or the bus 909.

[0147] The CPU 901 executes various processes according to the programs recorded in the recording device 917, thereby realizing the processes of the motor control unit 57, the brake control unit 59, the first data acquisition unit 63, the first abnormality determination unit 65, the inertia moment estimation unit 67, the disturbance torque estimation unit 69, the second data acquisition unit 71, the second abnormality determination unit 73, and the like. The CPU 901 may, for example, directly read and execute the program from the recording device 917, or may temporarily load the program into the RAM 905 and then execute it. The CPU 901 may, for example, directly execute the program when it receives the program via the communication device 923, the driver 919, or the connection port 921, without recording the received program in the recording device 917.

[0148] The CPU 901 may also perform various processes as needed based on signals and information input from an input device 913 such as a mouse, keyboard, or microphone (not shown).

[0149] The CPU 901 may also output the results of the above-mentioned processing from an output device 915, such as a display device or an audio output device. The CPU 901 may also transmit the processing results via the communication device 923 or the connection port 921 as needed. The CPU 901 may also record the processing results in the recording device 917 or the recording medium 925.

[0150] In addition to the methods described above, the methods of the above-mentioned embodiments and modifications may be appropriately combined. In addition, although not illustrated one by one, the above-mentioned embodiments and modifications may be implemented with various modifications without departing from the scope of the gist thereof.

[0151] The problems and effects to be solved by the above-described embodiments, modifications, etc. are not limited to the above-described contents. Through the embodiments, modifications, etc., it is also possible to solve the above-described problems or achieve the above-described effects, and sometimes only solve part of the described problems or achieve only part of the described effects.

Claims

1. An abnormality determination system for determining that a release action of a brake for braking a motor is abnormal, wherein: The abnormality determination system has: a first data acquisition unit that acquires time-series data related to a release operation state of the brake; a sample data creating unit that creates sample data based on the time series data when an abnormality occurs in the release operation of the brake; as well as A first abnormality determination unit determines whether a release operation of the brake is abnormal based on the time-series data acquired by the first data acquisition unit and the sample data.

2. The abnormality determination system according to claim 1, wherein: The first abnormality determination unit includes: A Mahalanobis distance calculation unit that calculates the Mahalanobis distance based on the sample data and the time series data; and A determination unit determines that the release operation of the brake is abnormal by comparing the Mahalanobis distance with a threshold value.

3. The abnormality determination system according to claim 1 or 2, wherein: The abnormality determination system further includes an action instruction output unit that outputs an action instruction for causing the motor to operate; The first data acquisition unit acquires the time series data before the motion instruction output unit outputs the motion instruction. The first abnormality determination unit determines abnormality in the release operation of the brake based on the time-series data and the sample data before the operation command output unit outputs the operation command.

4. The abnormality determination system according to claim 3, wherein: The abnormality determination system also has: a second data acquisition unit that acquires state quantity data related to the operating state of the motor after the operating command output unit outputs the operating command; and A second abnormality determination unit determines an abnormality in the release operation of the brake based on the state quantity data after the operation command output unit outputs the operation command.

5. The abnormality determination system according to claim 1, wherein: The first data acquisition unit acquires the time-series data from an acceleration sensor that detects vibration caused by a release operation of the brake.

6. The abnormality determination system according to claim 4, wherein: The abnormality determination system also has: a release command output unit that outputs a release command for releasing the brake; and an inertia moment estimation unit that estimates the inertia moment of the motor, The second data acquisition unit acquires, as the state quantity data, an estimated value of the moment of inertia at a time when the motion instruction output unit first outputs the motion instruction after the release instruction output unit outputs the release instruction. The second abnormality determination unit determines an abnormality in the release operation of the brake based on the estimated value of the moment of inertia.

7. The abnormality determination system according to claim 4 or 6, wherein: The abnormality determination system also has: a release command output unit that outputs a release command for releasing the brake; and a disturbance torque estimating unit for estimating the disturbance torque of the motor, The second data acquisition unit acquires, as the state quantity data, an estimated value of the disturbance torque at a time when the motion command output unit first outputs the motion command after the release command output unit outputs the release command. The second abnormality determination unit determines an abnormality in the release operation of the brake based on the estimated value of the disturbance torque.

8. An abnormality determination system for determining an abnormality in a release operation of a brake for braking a motor, wherein: The abnormality determination system has: an action instruction output unit for outputting an action instruction for causing the motor to operate; a first data acquisition unit that acquires time-series data related to a state of a release operation of the brake before the operation command output unit outputs the operation command; a first abnormality determination unit that determines an abnormality in the release operation of the brake based on the time-series data before the operation command output unit outputs the operation command; a second data acquisition unit for acquiring state quantity data related to an operating state of the motor after the operating command output unit outputs the operating command; as well as A second abnormality determination unit determines an abnormality in the release operation of the brake based on the state quantity data after the operation command output unit outputs the operation command.

9. An abnormality determination system for determining an abnormality in a release operation of a brake for braking a motor, wherein: The abnormality determination system has: an action instruction output unit for outputting an action instruction for causing the motor to operate; a data acquisition unit configured to acquire state quantity data related to an operating state of the motor after the operating instruction output unit outputs the operating instruction; as well as An abnormality determination unit determines an abnormality in the release operation of the brake based on the state quantity data after the operation command output unit outputs the operation command.

10. An abnormality determination device for determining that a release action of a brake for braking a motor is abnormal, wherein: The abnormality determination device has: a first data acquisition unit that acquires time-series data related to a release operation state of the brake; as well as A first abnormality determination unit determines that the release operation of the brake is abnormal based on the time-series data acquired by the first data acquisition unit and sample data created based on the time-series data when an abnormality occurs in the release operation of the brake.

11. An abnormality determination device for determining an abnormality in a release operation of a brake for braking a motor, wherein: The abnormality determination device has: a first data acquisition unit that acquires time-series data related to a state of a release operation of the brake before outputting an operation command for operating the motor; a first abnormality determination unit that determines an abnormality in the release operation of the brake based on the time-series data before outputting the operation command; a second data acquisition unit that acquires state quantity data related to the operating state of the motor after outputting the operating command; as well as A second abnormality determination unit determines an abnormality in the release operation of the brake based on the state quantity data after outputting the operation command.

12. A method for determining an abnormality in a release action of a brake for braking a motor, wherein: The abnormality determination method has the following features: Acquiring time series data related to a release operation state of the brake; as well as Based on the acquired time-series data and sample data created based on the time-series data when an abnormality occurs in the release operation of the brake, it is determined that the release operation of the brake is abnormal.

13. A method for determining an abnormality in a release operation of a brake for braking a motor, wherein: The abnormality determination method has the following features: Before outputting an operation command for operating the motor, acquiring time series data related to a state of a release operation of the brake; Before outputting the operation command, determining an abnormality in the release operation of the brake based on the time series data; After outputting the action instruction, obtaining state quantity data related to the action state of the motor; as well as After the operation command is output, abnormality in the release operation of the brake is determined based on the state quantity data.

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