WO2020050237A1

WO2020050237A1 - Information processing device and information processing method

Info

Publication number: WO2020050237A1
Application number: PCT/JP2019/034519
Authority: WO
Inventors: 仁友定; 克行木村
Original assignee: オムロン株式会社
Priority date: 2018-09-07
Filing date: 2019-09-03
Publication date: 2020-03-12
Also published as: JP7103092B2; JP2020043651A

Abstract

The present invention quickly detects abnormalities. According to the present invention, within a coordinate space, a determination part (56) of a PLC (50) acquires threshold value ranges for rotational speed difference average values that correspond to average values for the torque of a motor (30) and determines whether speed difference average values that have been associated with average values for torque are within the threshold value ranges.

Description

Information processing apparatus and information processing method

The present invention relates to an information processing device and an information processing method.

装置 A device that monitors the operation of a movable device that performs a predetermined operation to detect the presence or absence of an abnormality in the movable device is used. In the power steering apparatus of Patent Document 1, the presence or absence of an abnormality is determined for each index by independently comparing a plurality of indexes with a threshold value.

Japanese Unexamined Patent Publication "JP-A-2016-064710"

場合 When a plurality of indices are related to each other, a change in the value of one index may change the normal range of another index. According to the power steering apparatus of Patent Literature 1, a threshold value is compared for each different index. For this reason, it is not possible to accurately determine the presence or absence of an abnormality in each index, and there is a possibility that the discovery of an abnormality in the movable device may be delayed. An object of one embodiment of the present invention is to detect the presence or absence of an abnormality at an early stage.

The present invention employs the following configuration in order to solve the above-described problems.

That is, the information processing apparatus according to one aspect of the present invention includes a first index and a first index associated with the rotation of the motor that causes the movable device to perform a predetermined operation when the driver rotates the motor based on the input instruction value. An acquisition unit that acquires two indices over time, a first feature amount computation unit that computes a first feature amount that is a feature amount of the first index in a predetermined period acquired by the acquisition unit, and an acquisition unit that acquires the first index. A second feature value calculation unit that calculates a second feature value of the second index, which is a feature value in the predetermined period, and a second feature value that defines a normal range of the second feature value and changes according to the first feature value. A second threshold value, and comparing the second feature value calculated by the second feature value calculation unit with the second threshold value to determine whether the second feature value is included in the normal range. It is provided with a judging unit for performing.

An information processing method according to one aspect of the present invention provides a first index and a second index associated with rotation of a motor that causes a movable device to perform a predetermined operation when the driver rotates the motor based on an input instruction value. Acquiring over time, a first feature amount calculating step of calculating a first feature amount, which is a feature amount of the first index acquired in the acquiring step during a predetermined period, and an acquisition step of acquiring the first index acquired in the acquiring step. A second feature value calculating step of calculating a second feature value which is a feature value of the second index during the predetermined period; and a second feature value defining a normal range of the second feature value and changing in accordance with the first feature value. Determining a second threshold value and determining whether or not the second feature value calculated in the second feature value calculation step is included in the normal range.

According to one aspect of the present disclosure, the presence or absence of an abnormality can be detected at an early stage.

FIG. 2 is a diagram illustrating an example of a functional block of the PLC according to the first embodiment. FIG. 3 is a diagram schematically illustrating an example of an application scene of the PLC according to the first embodiment. FIG. 4 is a diagram illustrating a state of a normal range calculated by a normal range calculation unit in a coordinate space according to the first embodiment. FIG. 4 is a diagram illustrating a temporal change of a motor torque when the movable device according to the first embodiment performs a predetermined operation. FIG. 5 is a diagram illustrating a temporal change of a rotation speed of a motor when the movable device according to the first exemplary embodiment performs a predetermined operation. FIG. 4 is a diagram illustrating a state of a change in a torque average value according to the first embodiment. FIG. 6 is a diagram illustrating a state of a change in a speed difference average value according to the first embodiment. FIG. 5 is a diagram illustrating a state where the first feature amount and the second feature amount are plotted in a coordinate space having the first feature amount and the second feature amount according to the first embodiment. FIG. 3 is a diagram illustrating a flow of processing of the PLC according to the first embodiment.

Hereinafter, an embodiment according to one aspect of the present invention (hereinafter, also referred to as “the present embodiment”) will be described with reference to the drawings.

§1 Application Example An example of a scene to which the present invention is applied will be described with reference to FIG. FIG. 2 is a diagram schematically illustrating an example of an application scene of a PLC (programmable logic controller) 50 according to the first embodiment. The PLC 50 according to the present embodiment is an example of the information processing apparatus of the present invention that detects an abnormality of the movable device 10 including the movable mechanism (the movable portion 13 and the ball screw 12) that performs a predetermined operation by the rotation of the motor 30 in real time. .

The movable system 1 includes the movable device 10, the motor 30, a driver 40 that controls the driving of the motor 30, and a PLC 50. The movable system 1 is, for example, a production facility used in a product manufacturing factory. The movable device 10 is a device that performs a predetermined operation, for example, by transmitting rotation of a motor 30 connected via the coupling 20. The movable device 10 may be any device that performs a predetermined operation when the rotation of the motor 30 is transmitted, and may be, for example, various devices such as a transport device used in a manufacturing plant, or used in a device other than the manufacturing plant. Devices such as various types of robots.

The PLC 50 may be any information processing device that acquires a plurality of indices associated with the rotation of the motor 30 over time and detects an abnormality of the movable device 10 based on the plurality of indices. As the information processing device, for example, , A server, or the like. The index associated with the rotation of the motor 30 is an index related to each other, such as a control value (input value) for controlling the motor 30 and an output value (measured value) associated with the rotation of the motor 30. Then, the PLC 50 determines whether there is an abnormality in the movable device 10 based on the plurality of indices. Specific examples of the index will be described later. For example, the PLC 50 determines whether the coordinates indicated by the first index and the second index fall within a normal range on a two-dimensional plane having the first index as the horizontal axis and the second index as the vertical axis. Then, it is determined whether or not the movable device 10 is abnormal. Specific examples of the index will be described later.

§2 Configuration Example A configuration example of the movable system 1 according to the first embodiment will be described with reference to FIG. The movable device 10 includes, for example, a base 11 having a linear guide, a ball screw 12, and a movable portion 13. The ball screw 12 is mounted on the base 11 so as to be parallel to the long axis direction of the base 11. The movable section 13 is mounted on the ball screw 12. One end of the ball screw 12 is connected to an output shaft of a motor 30 via a coupling 20.

(4) The rotation of the output shaft of the motor 30 (simply called the rotation of the motor 30) causes the ball screw 12 to rotate. Then, as the ball screw 12 rotates, the movable portion 13 moves (ie, moves) on the ball screw 12 and along the ball screw 12 as indicated by an arrow A1.

In the movable device 10, for example, the movable portion 13 moves from the vicinity of one end (the end closer to the motor 30) of the ball screw 12 to the vicinity of the other end (the end farther from the motor 30) (outbound path). The movable portion 13 moves from the vicinity of the other end of the ball screw 12 to the vicinity of one end (return direction) of the ball screw 12 as a one-cycle operation. . The predetermined operation in the movable device 10 may be the one-cycle operation or a plurality of cycles including the one-cycle operation a plurality of times.

実施 In the present embodiment, description will be made assuming that the motor 30 includes the encoder 35. The encoder 35 outputs information indicating the rotation direction and the rotation angle of the motor 30 to the driver 40 over time as a pulse signal.

The encoder 35 may be externally provided separately from the motor 30. When the encoder 35 is provided separately from the motor 30, for example, the encoder 35 is attached to the other end of the ball screw 12 (the end farther from the motor 30) via a coupling. Then, the encoder 35 outputs information indicating the rotation direction and the rotation angle of the ball screw 12 to the PLC 50 with time as a pulse signal.

Note that the encoder 35 built in the motor 30 or an external encoder 35 provided separately from the motor 30 makes contact between the rotating part and a sensing part that senses the rotation direction and the rotation angle of the rotating part. Contact type encoder, or a non-contact type encoder in which the rotating part and the sensing part are in non-contact.

For example, the driver 40 generates appropriate values of current and voltage based on the command value (target value) from the PLC 50 so that the number of revolutions of the motor 30 per unit time becomes the command value (target value). , And outputs the generated current and voltage to the motor 30. Thus, the driver 40 controls the rotation of the motor 30. For example, the driver 40 calculates the torque value of the motor 30 over time based on the current value and the voltage value of the current and the voltage output to the motor 30, and sequentially outputs the torque value to the PLC 50.

The instruction value (target value) from the PLC 50 input to the driver 40, the current value and the voltage value output from the driver 40 to the motor 30, and the torque value calculated from the current value and the voltage value are determined by the rotation of the motor 30. 7 is an example of a control value for controlling the motor 30 among the indices associated with.

Further, the driver 40 changes the angular velocity value (in other words, the rotation speed of the motor 30) which is the output value (measured value) accompanying the rotation of the motor 30 with time based on the pulse signal acquired from the encoder 35 provided in the motor 30. And sequentially output to the PLC 50.

In addition, for example, an acceleration sensor is attached to the movable unit 13, the acceleration sensor acquires the acceleration data of the movable unit 13 that moves with the rotation of the motor 30 over time, and the acceleration sensor determines the acceleration value indicating the acceleration value. The data may be sequentially output to the PLC 50 as an output value accompanying the rotation of the motor 30. Further, for example, a position sensor is attached to the movable unit 13, and the position sensor acquires the position data of the movable unit 13 that moves with the rotation of the motor 30 over time, and the position sensor acquires the position data of the movable unit 13. May be sequentially output to the PLC 50 as an output value associated with the rotation of the motor 30. Further, for example, a temperature sensor is attached to the motor 30, and the temperature sensor acquires temperature data of the motor 30 that rises with the rotation of the motor 30 over time, and the temperature sensor indicates a temperature indicating the temperature of the motor 30. The data may be sequentially output to the PLC 50 via the PLC 50 or the driver 40 as an output value accompanying the rotation of the motor 30.

As described above, the rotation speed of the motor 30 calculated from the pulse signal output from the motor 30 to the driver 40, or the acceleration value, position, temperature, and the like obtained from a separately provided sensor are determined by the rotation of the motor 30. 5 is an example of an output value (measured value) associated with the rotation of the motor 30 among indices associated with. Note that the output value (measured value) associated with the rotation of the motor 30 may be a value obtained by measuring with the rotation of the motor 30.

FIG. 1 is a diagram illustrating an example of functional blocks of the PLC 50 according to the first embodiment. The PLC 50 includes an instruction unit 51, a normal range calculation unit 52, a storage unit 53, an acquisition unit 54, a first feature value calculation unit 55a, a second feature value calculation unit 55b, and a determination unit 56. I have. Hereinafter, each unit included in the PLC 50 will be described.

FIG. 3 is a diagram illustrating a normal range calculated by the normal range calculation unit in the coordinate space according to the first embodiment. The normal range calculation unit 52 calculates a normal range of the feature amount of each of the plurality of indexes to be evaluated in a coordinate space using the feature amounts of the plurality of indexes to be evaluated as coordinate axes, and stores the calculation result in the storage unit. 53.

The plurality of indexes to be evaluated by the PLC 50 are indexes associated with the rotation of the motor 30. The plurality of indexes are indexes whose values change (degrade) at the same time as the motor 30 rotates. For example, the plurality of indices may be relevant indices such that the value of one index is changed (deteriorated) and the value of another index is also degraded. For example, as described above, control values (input values) for controlling the motor 30, output values (measurement values) associated with the rotation of the motor 30, and other related indices, and indices calculated from those indices. There may be.

The control value (input value) for controlling the motor 30 is, for example, an instruction value (target value) output from the PLC 50 to the driver 40, a current value and a voltage value generated based on the instruction value by the driver 40, and the current value. And a torque value calculated from the voltage value and the voltage value.

The output value (measured value) accompanying the rotation of the motor 30 is, for example, the rotation speed of the motor 30 at which the pulse signal output from the encoder 35 is calculated, or the acceleration value, position, and position obtained from a separately provided sensor. Temperature and the like can be mentioned.

Since the torque and the speed are indexes when the movable device 10 is moving, the abnormality of the movable device 10 is likely to be reflected in the values. Therefore, the presence or absence of an abnormality in the movable device 10 can be detected at an early stage.

Indices calculated from these indices are, for example, an expected value for an instruction value output from the PLC 50 to the driver 40 set in advance, and the expected value and an output value (measurement value) associated with the rotation of the motor 30 are set. Value) (which may be referred to as a turbulence component). In order to obtain the expected value, the storage unit 53 may create and store in advance a database representing the correspondence between the indicated value and the output value associated with the rotation of the motor 30 with respect to the indicated value. A transfer function indicating the correspondence between the value and the output value associated with the rotation of the motor 30 with respect to the indicated value may be created and stored in advance.

予測 The waveform of the predicted value corresponding to the waveform of the indicated value is a waveform that includes an expected deviation from the waveform of the indicated value. The output value accompanying the rotation of the motor 30 has a waveform that follows the waveform of the indicated value, but does not become exactly the same as the waveform of the indicated value, and some deviation occurs. In particular, the waveform of the predicted value is obtained immediately after the rising of the waveform of the indicated value (that is, immediately after the motor 30 starts rotating from a stopped state) and from the falling to the stop of the waveform of the indicated value (that is, from the deceleration state of the motor 30) Until the rotation stops), the deviation from the waveform of the indicated value increases. Therefore, the waveform of the expected value with respect to the waveform of the indicated value is grasped in advance, and if the waveform of the output value accompanying the rotation of the motor 30 follows the waveform of the expected value, the movable device 10 can move normally. In addition, when the deviation of the waveform of the output value due to the rotation of the motor 30 increases, it is possible to grasp that an abnormality has occurred in the movement of the movable device 10.

The characteristic amount of the index is the average value of the absolute value of the index in a predetermined period, the difference between the maximum value and the minimum value of the difference in a predetermined period, the variance of the difference in a predetermined period, the maximum value and the minimum value of the average in a predetermined period. This is a variation amount of the index in a predetermined period, such as a difference from the value. Note that the predetermined period may be a period of an integral multiple cycle (one or a plurality of cycles) of the movable device 10.

In the example shown in FIG. 3, the first index is a torque value, and the second index is a disturbance component of the rotation speed of the motor 30 (difference between a waveform of the rotation speed of the motor 30 and an ideal waveform). The x-axis represents a difference between the average maximum value and the minimum value in a predetermined period, which is an example of the feature amount (first feature amount) of the first index (torque value). The y-axis indicates an average value which is an example of a feature amount (second feature amount) of the second index (a disturbance component of the rotation speed of the motor 30).

Here, for example, when the PLC 50 controls the speed of the movable device 10 (that is, the speed control of the rotation of the motor 30), the factor that affects the production in the factory is the speed of the movable unit 13 in the movable device 10 (that is, the rotation of the motor 30). Speed). Then, the rotation speed of the motor 30 is adjusted by the voltage and current (that is, torque) input to the motor 30 by the driver 40. That is, the driver 40 inputs the voltage and the current (that is, torque) to the motor 30 so that the rotation speed of the motor 30 becomes a desired speed. Therefore, for example, when an abnormality occurs in the movable device 10, the characteristic amount of the voltage and current (that is, torque) input to the motor 30 by the driver 40 before the characteristic amount of the rotation speed of the motor 30 appears. Is affected.

Therefore, the torque value selected as the first index and the speed disturbance component selected as the second index are mutually related indexes. Then, by monitoring the characteristic amount of the rotation speed of the motor 30 and the characteristic amount of the torque that is the control value of the speed, the abnormality can be detected early.

Also, for example, when the temperature of the motor 30 changes, the average value of the torque values also changes. Therefore, the temperature and the torque value are mutually related indices. In addition, as described above, the plurality of indices to be evaluated by the PLC 50 include a control value (input value) for controlling the motor 30, an output value (measured value) associated with the rotation of the motor 30, and those indices. Are selected in combination with the indices calculated from.

The normal range calculation unit 52 repeats data sampling for a plurality of indexes to be evaluated, calculates a normal range in the feature amount of each index, defines a threshold that defines the normal range, and sets the threshold to The information is stored in the storage unit 53. In the example illustrated in FIG. 3, the normal range calculation unit 52 illustrates an example in which a threshold (first threshold) T1 and a threshold (second threshold) T2 are defined in the xy coordinate space. The threshold T1 is a threshold that defines a normal range that is a normal value without any problem. The threshold value T2 is a threshold value that defines a range surrounding the outside of the threshold value T1, and defines a warning range to be noted before an abnormality occurs. The range outside the threshold value T2 is an abnormal range indicating an abnormal value. The threshold value T1 is defined by coordinates (T1x: T1y). The threshold value T2 is defined by coordinates (T2x: T2y). Since the first index and the second index are indexes related to each other, for example, in the example illustrated in FIG. 3, the normal range has an elliptical shape. That is, the threshold values T1 and T2 in the y-axis direction vary depending on the value on the x-axis. Further, the threshold values T1 and T2 in the x-axis direction vary depending on the value of the y-axis.

指標 Note that the number of indices to be evaluated is not limited to two, and may be three or more. In this case, the normal range calculation unit 52 calculates a normal range not in two axes (xy axes) but in a multidimensional coordinate space of three or more axes in accordance with the number of types of indices, and determines a threshold range in each axis direction. Stipulate.

The storage unit 53 stores the normal range calculated by the normal range calculation unit 52. In the normal range, for example, as described above, the coordinates (T1x: T1y) are stored as the threshold T1, and the coordinates (T2x: T2y) are stored as the threshold T2. The storage unit 53 may be provided outside the PLC 50 or may be externally connected to the PLC 50.

(4) The instruction unit 51 outputs the instruction value to the driver 40. The instruction value output from the instruction unit 51 to the driver 40 is a target value of an output value accompanying rotation of the motor 30. For example, the instruction value output from the instruction unit 51 to the driver 40 may be a target value of the torque associated with the rotation of the motor 30 or a target value of the speed (angular speed, rotation speed) associated with the rotation of the motor 30. The target value may be a target value of the speed (moving speed) of the movable unit 13 associated with the rotation of the motor 30, or may be a target value of another value.

When the indicated value is the target value of the torque, the driver 40 obtains the indicated value from the instructing section 51, generates a current and a voltage having values such that the torque of the motor 30 becomes the indicated value, and generates the generated current. Then, the motor 30 is rotated by the voltage. Thereby, the motor 30 rotates so that the torque becomes the indicated value. When the instruction value is the target value of the rotating speed of the motor 30, the driver 40 obtains the instruction value from the instruction unit 51, and sets the current and the value of the value such that the rotating speed of the motor 30 becomes the instruction value. A voltage is generated, and the motor 30 is rotated by the generated current and voltage. Thereby, the motor 30 rotates so that the speed becomes the indicated value. When the instruction value is the target value of the speed of the movable unit 13, the driver 40 obtains the instruction value from the instruction unit 51, and outputs a current and a voltage of such values that the speed of the movable unit 13 becomes the instruction value. Then, the motor 30 is rotated by the generated current and voltage. As a result, the motor 30 rotates so that the speed of the movable unit 13 becomes the specified value.

In the case where the information processing apparatus according to the present invention is not a PLC but a server, a configuration in which the instruction unit 51 is omitted may be adopted.

FIG. 4 is a diagram illustrating a temporal change of the torque of the motor 30 when the movable device 10 according to the first embodiment performs a predetermined operation. FIG. 5 is a diagram illustrating a temporal change in the rotation speed of the motor 30 when the movable device 10 according to the first embodiment performs a predetermined operation.

The acquisition unit 54 acquires a plurality of indices from the driver 40 or various sensors provided separately. In the example illustrated in FIGS. 4 and 5, the acquisition unit 54 acquires the torque value from the driver 40 over time as the first index, and acquires the rotation speed value of the motor 30 from the driver 40 over time as the second index. I do. The horizontal axis shown in FIGS. 4 and 5 represents the same time. That is, FIGS. 4 and 5 show the change over time of the torque value (FIG. 4) and the change over time of the speed value (FIG. 5) at the same time. A period B1, a period B2, a period B3, and a period B4 shown in FIGS. 4 and 5 represent one cycle of the operation period of the movable device 10 at the same timing. When the index to be evaluated is an instruction value, the acquisition unit 54 may acquire the instruction value from the instruction unit 51.

FIG. 6 is a diagram showing a state of a change in the average torque value according to the first embodiment. The first feature value calculation unit 55a calculates a first feature value which is a feature value of the first index acquired by the acquisition unit 54 in a predetermined period. For example, the first feature amount calculating unit 55a features the average value of the torque values for each of the periods B1, B2, B3, and B4 shown in FIG. 4 from the torque values acquired by the acquiring unit 54. Calculate as a quantity. In the example shown in FIG. 6, the average value of the torque values for each of the periods B1, B2, B3, B4,. ing.

Note that the first feature value calculation unit 55a determines, as the first feature value, an average value, a variance, and a maximum value of the first index in a predetermined period (for example, each of the periods B1, B2, B3, B4,...). , The average of the difference between the predicted value of the output value associated with the rotation of the motor and the measured value of the output value, and the predicted value of the output value associated with the rotation of the motor 30 and the measured value of the output value Any one of the variances of the difference may be calculated.

FIG. 7 is a diagram illustrating a state of a change in the average speed difference value according to the first embodiment. The second feature value calculation unit 55b calculates a second feature value which is a feature value of the second index acquired by the acquisition unit 54 in a predetermined period. For example, the second feature amount calculating unit 55b calculates a speed difference (speed turbulence component) for each of the periods B1, B2, B3, and B4 shown in FIG. ) Is calculated as a feature value. In the example shown in FIG. 7, a temporal change in the average speed difference value in which the average speed difference value for each of the periods B1, B2, B3, B4,. .

The second feature value calculation unit 55b determines the average value, the variance, and the maximum value of the second index in a predetermined period (for example, each of the periods B1, B2, B3, B4,...) As the second feature amount. , The average of the difference between the predicted value of the output value associated with the rotation of the motor and the measured value of the output value, and the predicted value of the output value associated with the rotation of the motor 30 and the measured value of the output value Any one of the variances of the difference may be calculated.

FIG. 8 is a diagram illustrating a state where the first feature amount and the second feature amount are plotted in a coordinate space having the first feature amount and the second feature amount according to the first embodiment.

As illustrated in FIG. 8, for example, the determination unit 56 sets the average value of the torque (the first characteristic amount of the first index) on the x-axis and the average speed difference (the second characteristic amount of the second index) on the y-axis. Xy coordinates are created. Then, when the temporal change of the average value of the torque value from the first characteristic amount calculating unit 55a shown in FIG. 6 and the temporal change of the average speed difference value from the second characteristic amount calculating unit 55b shown in FIG. The average value of the torque and the average value of the speed difference at the same time are associated with each other and plotted on the xy coordinate space. That is, the determination unit 56 creates coordinate data (x: y) using the average value of the torque as the x coordinate and the average value of the speed difference as the y coordinate.

Then, the determination unit 56 refers to the normal range stored in the storage unit 53, and calculates the first feature value (x value) calculated by the first feature value calculation unit 55a in the coordinate data plotted in the xy coordinate space. A second threshold value (a value range of the y-coordinate of the threshold T1 and a value range of the y-coordinate of the threshold T2) that changes accordingly is acquired. Then, if the value of y in the coordinate data is included in the second threshold value (the value range of the y coordinate of the threshold T1 and the value range of the y coordinate of the threshold T2), the value of y is within the normal range. Is determined.

Note that the determination unit 56 warns the user if the y value of the coordinate data is outside the y coordinate value range of the threshold value T1 and is within the y coordinate value range of the threshold value T2. Perform notification processing. When the value of y of the coordinate data is out of the range of the y coordinate of the threshold value T2, the determination unit 56 determines that the value of y is an abnormal value, and notifies the user of the abnormality. Perform error notification processing.

In this way, for example, among the torque (first index) and the speed (second index), which are indexes related to each other, a speed difference between the speeds according to the torque average (first characteristic amount) which is the characteristic amount of the torque. An accurate normal range of the average value (second feature amount) can be obtained as the second threshold. Thereby, the presence or absence of abnormality of the movable device 10 can be detected at an early stage.

In addition, the determination unit 56 determines a first threshold (a value range of the x coordinate of the threshold T1; a first threshold that changes according to the second feature amount (the value of y) of the coordinate data that has determined whether or not the y coordinate is normal; (The value range of the x coordinate of the threshold value T2). Then, if the value of x in the coordinate data is included in the first threshold (the value range of the x coordinate of the threshold T1 and the value of the x coordinate of the threshold T2), the value of x is within the normal range. Is determined.

Note that the determination unit 56 determines that the value of x is within the normal range if the value of x of the coordinate data is outside the value range of the x coordinate of the threshold T1 and within the value range of the x coordinate of the threshold T2. In order to warn the user, a warning notification process to the user is performed. When the value of x of the coordinate data is out of the range of the x coordinate of the threshold value T2, the determination unit 56 determines that the value of x is an abnormal value, and notifies the user of the abnormality. Perform error notification processing.

As described above, for example, of the torque (first index) and the speed (second index), which are indexes related to each other, the torque of the torque according to the speed difference average value (second feature value) that is the feature value of the speed is obtained. An accurate normal range of the average value (first feature amount) can be obtained as the first threshold. Thereby, the presence or absence of abnormality of the movable device 10 can be detected at an early stage. It should be noted that the index to be evaluated may have a relationship that affects another index when one indicator changes, or the value changes at the same time even if it does not have the relationship (deterioration). ) May be used.

When there are three or more types of indices to be evaluated, the determination unit 56 plots coordinate data in a three-dimensional or more multidimensional space corresponding to the type, and determines whether the coordinate data is within a normal range. Determine whether or not.

In addition, the determination unit 56 first determines whether the value of x is within the value range of the x coordinate of the threshold value T1 or is within the value range of the x coordinate value of the threshold value T2. Then, it may be determined whether the value of y is within the value range of the y-coordinate of the threshold T1 or whether it is within or outside the value range of the y-coordinate of the threshold T2. When the determination unit 56 determines that the previously determined value (for example, the value of y) of the coordinate data is out of the range of the threshold value T2 (warning range), the other value (for example, the value of x) May be performed without determining whether or not is within the value range of the coordinates of the threshold T1 and the threshold T2.

処理 Note that the process of notifying the user includes various methods for notifying the user. Examples of the process of notifying the user include displaying a screen for notifying the user on the display when the movable system 1 includes a display, and outputting a sound for notifying the user when the movable system 1 includes a speaker. For example, to output the data to Alternatively, as a process of notifying the user, for example, a process of notifying the user by sending an e-mail to an address designated by the user, or a process of turning on or blinking the lamp when the movable system 1 includes a lamp And the like.

FIG. 9 is a diagram illustrating a processing flow of the PLC 50 according to the first embodiment. First, the normal range calculation unit 52 calculates thresholds (thresholds T1 and T2) that define a normal range of each feature in a multidimensional coordinate space in which each feature of the index to be evaluated is used as a coordinate axis. Step S10). Next, the acquisition unit 54 acquires a first index such as a torque value and a second index such as a speed value from the driver 40 with time (step S11).

Then, the first feature value calculation unit 55a calculates an average value (first feature value) which is a feature value of the first index such as the torque value acquired by the acquisition unit 54 in a predetermined period (step S12). The first feature value calculation unit 55a outputs the calculated average value (first feature value) to the determination unit 56 over time.

{Circle around (2)} The second feature value calculation unit 55b calculates a speed difference average value (second feature value) as a feature value of the second index such as the speed value acquired by the acquisition unit 54 in a predetermined period (step S13). The second feature value calculation unit 55b outputs the calculated speed difference average value (second feature value) to the determination unit 56 over time.

Next, the determination unit 56 creates a coordinate space in which the average value of the torque (first feature value) is set as the x coordinate and the average value of the speed difference (second feature value) is set as the y coordinate. Then, the determination unit 56 sets the average value (first feature amount) obtained from the first feature amount calculation unit 55a as the value of x, and obtains the speed difference obtained from the second feature amount calculation unit 55b at the same time as the average value. Coordinate data with the average value (second feature amount) as the value of y is created and plotted in the xy coordinate space. Then, the determination unit 56 refers to the normal range stored in the storage unit 53, and sets a threshold value of the y value (second feature amount) corresponding to the x value (the average value of torque) among the plotted coordinate data. (The value range of the y-coordinate of the threshold T1 and the value range of the y-coordinate of the threshold T2) are acquired (step S14).

Further, the determination unit 56 refers to the normal range stored in the storage unit 53, and among the coordinate data plotted in the coordinate space, the value of x (first characteristic amount) corresponding to the value of y (average speed difference value) ) (The value range of the x coordinate of the threshold T1 and the value range of the x coordinate of the threshold T2) are acquired (step S15).

Then, in step S16, if both the value of x and the value of y are within the range of the threshold value T1 (YES in step S16), the determination unit 56 determines that the coordinate data is a value in the normal range. The process returns to step S11.

In addition, in step S16, the determination unit 56 determines whether or not at least one of the value of x and y is in a range greater than the threshold T1 and equal to or less than the threshold T2 (step S17). Then, in step S17, when the determining unit 56 determines that at least one of the value of x and the value of y is in a range that is larger than the threshold value T1 and equal to or smaller than the threshold value T2 (YES in step S17), the coordinate data is set in the warning range. It is determined that it is included, and a warning notification process to the user is performed (step S18). In step S17, when at least one of the value x and the value y is larger than the threshold value T2 (NO in step S17), the determination unit 56 determines that the coordinate data is abnormal, and notifies the user of the abnormality. The process is performed (Step S19).

[Example of software implementation]
The control blocks of the PLC 50 (especially, the instruction unit 51, the normal range calculation unit 52, the acquisition unit 54, the first feature calculation unit 55a, the second feature calculation unit 55b, and the determination unit 56) are integrated circuits (IC chips) and the like. It may be realized by a formed logic circuit (hardware) or by software.

In the latter case, the PLC 50 includes a computer that executes instructions of a program that is software for realizing each function. The computer includes, for example, one or more processors and a computer-readable recording medium storing the program. Then, in the computer, the object of the present invention is achieved when the processor reads the program from the recording medium and executes the program. As the processor, for example, a CPU (Central Processing Unit) can be used. Examples of the recording medium include "temporary tangible media" such as ROM (Read Only Memory), tapes, disks, cards, semiconductor memories, and programmable logic circuits. Further, a RAM (Random Access Memory) for expanding the above program may be further provided. Further, the program may be supplied to the computer via an arbitrary transmission medium (a communication network, a broadcast wave, or the like) capable of transmitting the program. Note that one embodiment of the present invention can also be realized in the form of a data signal embedded in a carrier wave, in which the program is embodied by electronic transmission.

(Appendix)
An information processing apparatus according to one aspect of the present invention includes a first index and a second index associated with rotation of a motor that causes a movable device to perform a predetermined operation when the driver rotates the motor based on an input instruction value. An acquisition unit that acquires the first index over time, a first feature quantity computation unit that computes a first feature quantity that is a feature quantity in a predetermined period of the first index acquired by the acquisition unit, and a second feature quantity that is acquired by the acquisition unit. A second feature value calculation unit that calculates a second feature value of the index during the predetermined period; and a second threshold value that defines a normal range of the second feature value and changes according to the first feature value. And comparing the second feature value calculated by the second feature value calculation unit with the second threshold value to determine whether or not the second feature value is included in the normal range. It has a part.

According to the above configuration, an accurate normal range of the second feature value according to the first feature value, which is the feature value of the first index, out of the first index and the second index can be obtained as the second threshold value. Thus, the presence or absence of an abnormality in the movable device can be detected at an early stage.

The determination unit defines a normal range of the first feature amount and obtains a first threshold value that changes according to the second feature amount, and obtains the first feature amount calculated by the first feature amount calculation unit. By comparing the first feature value with the first threshold value, it may be determined whether or not the first feature value is included in the normal range. According to the above configuration, an accurate normal range of the first characteristic amount according to the second characteristic amount, which is the characteristic amount of the second index, of the first index and the second index can be obtained as the first threshold. Thus, the presence or absence of an abnormality in the movable device can be detected at an early stage.

正常 The normal range may be elliptical.

The first feature amount is an average value, a variance, a difference between a maximum value and a minimum value, a predicted value of an output value accompanying rotation of a motor, and a measured value of the output value of the first index during the predetermined period. It may be any of the average of the differences and the variance of the difference between the predicted value of the output value due to the rotation of the motor and the measured value of the output value.

The second feature amount is an average value, a variance, a difference between a maximum value and a minimum value, a predicted value of an output value accompanying rotation of the motor, and a measured value of the output value of the second index in the predetermined period. It may be any of the average of the differences and the variance of the difference between the predicted value of the output value due to the rotation of the motor and the measured value of the output value.

The first index and the second index are different from each other, and may be any one of a torque associated with the rotation of the motor, a speed at which the motor rotates, and an operation speed of the movable device according to the rotation of the motor. It may be. Since the torque and the speed are indexes when the movable device is moving, the abnormality of the movable device is likely to be reflected in the values. Therefore, the presence or absence of an abnormality in the movable device can be detected at an early stage.

The present invention is not limited to the embodiments described above, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Movable system 10 Movable device 11 Base 12 Ball screw 13 Movable part 20 Coupling 30 Motor 35 Encoder 40 Driver 50 PLC
51 instruction unit 52 normal range calculation unit 53 storage unit 54 acquisition unit 55a first feature value calculation unit 55b second feature value calculation unit 56 determination unit

Claims

An acquisition unit configured to sequentially acquire a first index and a second index associated with rotation of the motor when the driver rotates the motor that causes the movable device to perform the predetermined operation based on the input instruction value;
A first feature value calculation unit that calculates a first feature value that is a feature value of the first index acquired by the acquisition unit during a predetermined period;
A second feature value calculation unit that calculates a second feature value of the second index acquired by the acquisition unit during the predetermined period;
A second threshold value that defines a normal range of the second feature value and changes in accordance with the first feature value is obtained, and the second feature value and the second threshold value calculated by the second feature value calculation unit are calculated. An information processing apparatus comprising: a determination unit that determines whether the second feature amount falls within the normal range by comparing
The determination unit defines a normal range of the first feature amount and obtains a first threshold value that changes according to the second feature amount, and obtains the first feature amount calculated by the first feature amount calculation unit. The information processing apparatus according to claim 1, wherein it is determined whether the first feature value is included in the normal range by comparing the first feature value with the first threshold value.
The information processing apparatus according to claim 1 or 2, wherein the normal range has an elliptical shape.
The first feature amount is:
The first index in the predetermined period, the average value, the variance, the difference between the maximum value and the minimum value, the average of the difference between the predicted value of the output value accompanying the rotation of the motor and the measured value of the output value, and 4. The information processing apparatus according to claim 1, wherein the information is a variance of a difference between a predicted value of an output value and a measured value of the output value due to the rotation of.
The second feature amount is:
The second index in the predetermined period, the average value, the variance, the difference between the maximum value and the minimum value, the average of the difference between the predicted value of the output value accompanying the rotation of the motor and the measured value of the output value, and The information processing apparatus according to any one of claims 1 to 4, wherein the information is any one of a variance of a difference between a predicted value of the output value and a measured value of the output value due to the rotation of (i).
The first index and the second index are different from each other, and may be any one of a torque associated with the rotation of the motor, a speed at which the motor rotates, and an operation speed of the movable device according to the rotation of the motor. The information processing apparatus according to any one of claims 1 to 5, wherein
An acquisition step of acquiring a first index and a second index associated with the rotation of the motor when the driver rotates the motor that causes the movable device to perform the predetermined operation based on the input instruction value over time;
A first feature value calculation step of calculating a first feature value which is a feature value of the first index acquired in the acquisition step during a predetermined period;
A second feature value calculation step of calculating a second feature value which is a feature value of the second index acquired in the acquisition step during the predetermined period;
The normal range of the second feature value is defined, and a second threshold value that changes in accordance with the first feature value is acquired, and the second feature value calculated in the second feature value calculation step falls within the normal range. A determining step of determining whether or not the information is included.