Data processing method and data processing apparatus

Abstract

To obtain appropriate analysis results by analyzing waveform data.SOLUTION: A data processing method performed by a data processing device includes: an acquisition step of acquiring waveform data output from a sensor that detects a physical quantity that changes according to the operation of an actuator and is provided on a machine equipped with the actuator that operates according to a control mode; and an extraction step of extracting feature quantities from a predetermined extraction target section of the waveform data and causing a change of a length of the extraction target section depending on the control mode of the actuator when the physical quantities are detected by the sensor.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a data processing method and a data processing apparatus.

Background Art

[0002] Patent Document 1 describes a technique of detecting vibrations, sounds, deflections of components, etc. generated during the operation of a machine by a sensor and analyzing the waveform of the output signal of the sensor.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Even if waveform data is analyzed in the same way when the control mode of the machine is in the position control mode and when it is in the speed control mode, appropriate analysis results may not be obtained. Therefore, a technique for analyzing waveform data to obtain appropriate analysis results is desired.

Means for Solving the Problems

[0005] The present disclosure can be realized in the following forms.

[0006] (1) According to a first aspect of the present disclosure, a data processing method executed by a data processing apparatus is provided. This data processing method includes an acquisition step of acquiring waveform data output from a sensor provided in a machine including an actuator that operates according to a control mode, the sensor detecting a physical quantity that changes according to the operation of the actuator, and an extraction step of extracting a feature amount from a predetermined extraction target section of the waveform data, the extraction step varying the length of the extraction target section according to the control mode of the actuator when the physical quantity is detected by the sensor. According to the data processing method of this aspect, it is possible to suppress the extraction of a feature amount from an inappropriate extraction target section, and thus it is possible to suppress the failure to obtain an appropriate analysis result of the waveform data. (2) In the data processing method of the above aspect, in the extraction step, the length of the extraction target section when the control mode is the position control mode may be made shorter than the length of the extraction target section when the control mode is not the position control mode. According to the data processing method of this aspect, it is possible to suppress the extraction of a feature amount from an inappropriate extraction target section when the control mode of the actuator is the position control mode. (3) In the data processing method of the above aspect, in the extraction step, when the control mode is the position control mode, the section from the timing when the operation of the actuator starts to the timing when the operation of the actuator starts next may be set as the extraction target section. According to the data processing method of this aspect, it is possible to suppress the extraction of a feature amount from an inappropriate extraction target section when the control mode of the actuator is the position control mode. (4) In the data processing method of the above aspect, in the extraction step, when the control mode is not the position control mode, the entire waveform data may be set as the extraction target section. According to the data processing method of this aspect, it is possible to suppress the extraction of a feature amount from an inappropriate extraction target section when the control mode of the actuator is not the position control mode. (5) The data processing method of the above form may have a determination step of determining the presence or absence of an abnormality of the machine using the feature amount. According to the data processing method of this form, the presence or absence of an abnormality of the machine can be accurately determined. (6) According to the second form of the present disclosure, a data processing device is provided. This data processing device is a sensor provided in a machine including an actuator that operates according to a control mode, and acquires waveform data output from a sensor that detects a physical quantity that changes according to the operation of the actuator, and an extraction unit that extracts a feature amount from a predetermined extraction target section among the waveform data, and the extraction unit that varies the length of the extraction target section according to the control mode of the actuator when the physical quantity is detected by the sensor. According to the data processing device of this form, it is possible to suppress the extraction of a feature amount from an inappropriate extraction target section, so it is possible to suppress the failure to obtain an appropriate analysis result of the waveform data. The present disclosure can also be realized in various forms other than the data processing method and the data processing device. For example, it can be realized in the form of a feature amount extraction method, a feature amount extraction device, an abnormality detection method, an abnormality detection device, and the like.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Embodiments for Carrying Out the Invention

[0008] A. First Embodiment: FIG. 1 is an explanatory diagram schematically showing the configuration of a data processing apparatus 100 according to the first embodiment. The data processing apparatus 100 includes a CPU 101, a memory 102, an input / output interface 103, and an internal bus 104. The CPU 101, the memory 102, and the input / output interface 103 are connected to be communicable bidirectionally via the internal bus 104. A sensor 250 provided in the machine 200 is connected to the input / output interface 103. In the present embodiment, in addition to the sensor 250, an input device 105 and a display device 106 are connected to the input / output interface 103. The input device 105 is, for example, a keyboard or a mouse, and the display device 106 is, for example, a liquid crystal display. Note that the input device 105 and the display device 106 may be integrated as a touch panel.

[0009] The CPU 101 functions as an acquisition unit 110, an extraction unit 120, and a determination unit 130 by executing a computer program stored in advance in the memory 102. The acquisition unit 110 acquires waveform data output from the sensor 250. The extraction unit 120 extracts a feature amount from an extraction target section of the waveform data. The determination unit 130 determines the presence or absence of an abnormality in the machine 200 using the feature amount, and causes the display device 106 to display the determination result.

[0010] The machine 200 includes an actuator 210, a control device 220 that controls the actuator 210, and a sensor 250. In the present embodiment, the machine 200 is a processing machine such as a machining center that processes a workpiece, and the actuator 210 is a servo motor that moves a table to which the workpiece is fixed. The actuator 210 and the control device 220 are configured to be operable in a position control mode with the position of the table as a target value. Note that the machine 200 is not limited to a processing machine, and may be, for example, a transport device that transports a workpiece. The actuator 210 is not limited to a servo motor, and may be, for example, a stepping motor or a power cylinder such as an electric cylinder.

[0011] The sensor 250 detects a physical quantity that changes according to the operation of the actuator 210. In the present embodiment, the sensor 250 is a torque sensor that detects the torque generated by the servo motor that is the actuator 210. The sensor 250 is not limited to a torque sensor, and for example, a current sensor that detects the current supplied to the actuator 210 may be used. The number of sensors 250 may be one or plural.

[0012] FIG. 2 is a flowchart showing the content of the data processing method executed by the data processing apparatus 100. FIG. 3 is an explanatory diagram showing an example of the waveform data Wt. FIG. 4 is an explanatory diagram showing an example of the determination result by the determination unit 130. In the present embodiment, the data processing method shown in FIG. 2 is repeatedly executed by the data processing apparatus 100 at a predetermined time interval while the power of the machine 200 is on.

[0013] First, in step S110, the acquisition unit 110 acquires the waveform data Wt output from the sensor 250 that detects the torque of the servo motor that is the actuator 210. In the present embodiment, in addition to the sensor 250 that detects the torque of the servo motor, the machine 200 is provided with a rotation speed sensor that detects the rotation speed of the servo motor, and the acquisition unit 110 acquires, in addition to the waveform data Wt of the torque, the waveform data Ws output from the rotation speed sensor.

[0014] In step S120, the extraction unit 120 determines whether or not the control mode of the actuator 210 is the position control mode. In the present embodiment, the control mode of the actuator 210 is input by the user via the input device 105. Note that the process of step S120 may be executed prior to the process of step S110.

[0015] When it is determined in step S120 that the control mode of the actuator 210 is the position control mode, the extraction unit 120 acquires, from the control device 220, stop flag data representing a chronological change in whether the operation of the actuator 210 is stopped or not in step S130, and determines, in step S135, an extraction target section for extracting a feature amount from the waveform data Wt by using the stop flag data. Specifically, the extraction unit 120 divides the waveform data Wt into a plurality of sections with the timing when the operation of the actuator 210 starts as a boundary, and determines each section from the timing when the operation of the actuator 210 starts to the next timing when the operation of the actuator 210 starts as an extraction target section. As shown in FIG. 3, when the first operation of the actuator 210 is stopped after starting at time t1, the second operation is stopped after starting at time t2, the third operation is stopped after starting at time t3, and the operation is not started thereafter, the extraction unit 120 determines the section S1 from time t1 to time t2 as the first extraction target section, and determines the section S2 from time t2 to time t3 as the second extraction target section. In the present embodiment, the extraction unit 120 also determines the section S3 from time t3 to the end of the waveform data Wt as an extraction target section.

[0016] When it is determined in step S120 that the control mode is not the position control mode, the extraction unit 120 determines, in step S140, the entire S0 of the waveform data Wt as an extraction target section. That is, the extraction unit 120 varies the length of the extraction target section along the time axis according to the control mode of the actuator 210. Specifically, the extraction unit 120 makes the length of the extraction target section when the control mode of the actuator 210 is the position control mode shorter than the length of the extraction target section when the control mode is not the position control mode. Note that control modes other than the position control mode include, for example, a speed control mode in which the actuator 210 is controlled with the speed of the part moved by the actuator 210 as a target value, and an acceleration control mode in which the actuator 210 is controlled with the acceleration of the part moved by the actuator 210 as a target value.

[0017] In step S150, the extraction unit 120 extracts a plurality of feature amounts from the extraction target section determined in step S135 or step S140. FIG. 4 shows an example of the feature amounts extracted by the extraction unit 120 in the case of the position control mode. The stop torque amplitude represents the maximum value of the torque amplitude during the rotation stop of the actuator 210. The plus-side acceleration torque represents the maximum value of the absolute value of the positive torque during rotation acceleration, the minus-side acceleration torque represents the maximum value of the absolute value of the negative torque during rotation acceleration, the plus-side deceleration torque represents the maximum value of the absolute value of the positive torque during rotation deceleration, and the minus-side deceleration torque represents the maximum value of the absolute value of the negative torque during rotation deceleration. The operating torque amplitude represents the maximum value of the torque amplitude during rotation acceleration and rotation deceleration. The damped vibration represents the maximum value of the amplitude of the damped vibration during constant-speed rotation and rotation stop, and the continuous vibration represents the maximum value of the torque amplitude during constant-speed rotation. The driving energy is calculated by dividing the sum of the torques in the portion where the direction of rotation and the direction of torque match, excluding the portion during rotation stop, by the number of samples. The regenerative energy is calculated by dividing the sum of the torques in the portion where the direction of rotation and the direction of torque do not match, excluding the portion during rotation stop, by the number of samples. The maximum torque represents the maximum value of the torque, and the minimum torque represents the minimum value of the torque. The average loss is calculated by dividing, excluding the portion during rotation stop, the value obtained by subtracting the sum of the torques in the portion where the direction of rotation and the direction of torque do not match from the sum of the torques in the portion where the direction of rotation and the direction of torque match, by the number of samples. Note that the number of feature amounts extracted by the extraction unit 120 may be one instead of a plurality. In the case of not being in the position control mode, the extraction unit 120 may extract, as feature amounts, the load factor in one cycle and the load factor in a short time. The load factor in one cycle represents the effective torque in one cycle of the operation of the actuator 210, and the load factor in a short time represents the maximum value of the effective torque in the time window when a time window with a predetermined width is slid in the extraction target section.

[0018] In step S160, the determination unit 130 determines the presence or absence of an abnormality in the machine 200 using the feature amounts. In the present embodiment, threshold values for each feature amount are stored in advance in the memory 102, and the determination unit 130 determines the presence or absence of an abnormality in the machine 200 by comparing the threshold values stored in the memory 102 with the feature amounts. The determination unit 130 determines that there is an abnormality when one or more feature amounts are equal to or greater than the threshold value, and determines that there is no abnormality when all the feature amounts are less than the threshold value. Note that the same threshold value or different threshold values may be used depending on whether it is determined in step S120 that the position control mode is in effect or not in effect.

[0019] In step S170, the determination unit 130 causes the display device 106 to display the determination result. An example of the determination result is shown in FIG. 4. In the example of FIG. 4, since the torque amplitude during stop is equal to or greater than the threshold value, it is determined that there is an abnormality in the machine 200. For example, when the actuator 210 is operating in the position control mode and the table moved by the actuator 210 stops before reaching the target position due to foreign matter being caught, the torque of the actuator 210 increases in order to move the table to the target position. However, since the rotation of the actuator 210 is inhibited by the foreign matter being caught, the torque amplitude during stop increases. Therefore, when the torque amplitude during stop is equal to or greater than the threshold value, there is a possibility that foreign matter has been caught.

[0020] Thereafter, the data processing device 100 ends this process. Note that step S110 of the data processing method may be referred to as the acquisition step, steps S120 to S150 may be referred to as the extraction step, step S160 may be referred to as the determination step, and step S170 may be referred to as the determination result output step.

[0021] According to the data processing apparatus 100 in the present embodiment described above, the extraction unit 120 varies the length of the extraction target section according to the control mode of the actuator 210. Specifically, when it is determined that the control mode of the actuator 210 is the position control mode, the extraction unit 120 makes the length of the extraction target section shorter than the length of the extraction target section when it is determined that the control mode is not the position control mode. Therefore, according to the control mode of the actuator 210, the feature amount can be extracted from the extraction target section suitable for the analysis of the waveform data Wt. Thus, it is possible to suppress the situation where the feature amount is extracted from an inappropriate extraction target section and the waveform data Wt cannot be appropriately analyzed. In order to appropriately analyze the waveform data Wt, in the position control mode, for each section corresponding to the period during which each positioning operation by the machine 200 is executed in the waveform data Wt, the feature amount is extracted with that section as the extraction target section, and when it is not in the position control mode, it is preferable to extract the feature amount with the entire waveform data Wt as the extraction target section. In the present embodiment, when it is determined that the control mode of the actuator 210 is the position control mode, the extraction unit 120 determines each section from the timing when the operation of the actuator 210 starts to the timing when the operation of the actuator 210 starts next in the waveform data Wt as the extraction target section, and when it is determined that the control mode is not the position control mode, determines the entire waveform data Wt as the extraction target section. Therefore, the waveform data Wt can be appropriately analyzed using the feature amount extracted from the extraction target section. Furthermore, in the present embodiment, since the extraction unit 120 automatically determines the extraction target section instead of the user determining the extraction target section, it is possible to prevent the feature amount from being extracted from an inappropriate extraction target section due to human error.

[0022] Also, in the present embodiment, the determination unit 130 determines the presence or absence of an abnormality of the machine 200 using the feature amount extracted from the extraction target section. Therefore, using the appropriately extracted feature amount, the presence or absence of an abnormality of the machine 200 can be accurately determined. Furthermore, since the determination unit 130 causes the display device 106 to display the determination result, the user can grasp the presence or absence of an abnormality and then perform inspection of the machine 200 and replacement of parts to prevent a failure of the machine 200.

[0023] B. Other Embodiments: (B1) In the data processing apparatus 100 of the first embodiment described above, when the control mode of the actuator 210 is the position control mode, the extraction unit 120 makes the length of the extraction target section shorter than the length of the extraction target section when the control mode is not the position control mode. On the contrary, the extraction unit 120 may make the length of the extraction target section longer than the length of the extraction target section when the control mode is not the position control mode, when the control mode of the actuator 210 is the position control mode.

[0024] (B2) In the data processing apparatus 100 of the first embodiment described above, when the control mode of the actuator 210 is the position control mode, the extraction unit 120 sets, as the extraction target section, the section of the waveform data Wt from the timing when the operation of the actuator 210 starts to the timing when the operation of the actuator 210 next starts. On the contrary, when the control mode of the actuator 210 is the position control mode, the extraction unit 120 may set, as the extraction target section, the section of the waveform data Wt from the timing when the operation of the actuator 210 stops to the timing when the operation of the actuator 210 next stops.

[0025] (B3) In the data processing apparatus 100 of the first embodiment described above, when the control mode of the actuator 210 is not the position control mode, the extraction unit 120 sets the entire waveform data Wt as the extraction target section. On the contrary, when the control mode of the actuator 210 is not the position control mode, the extraction unit 120 may set a partial section of the waveform data Wt as the extraction target section.

[0026] (B4) The data processing apparatus 100 of the first embodiment described above includes a determination unit 130 that determines the presence or absence of an abnormality in the machine 200 using the feature amount extracted by the extraction unit 120. On the contrary, it may not include the determination unit 130. In this case, the user may determine the presence or absence of an abnormality in the machine 200 using the feature amount extracted by the extraction unit 120.

[0027] (B5) In the data processing apparatus 100 of the first embodiment described above, a display device 106 is connected, and the determination unit 130 causes the display device 106 to display the determination result of the presence or absence of an abnormality in the machine 200. On the other hand, a warning lamp or a warning buzzer may be connected to the data processing apparatus 100. In this case, when the determination unit 130 determines that there is an abnormality in the machine 200, it may activate the warning lamp or the warning buzzer.

[0028] (B6) In the first embodiment described above, the data processing method is executed to detect an abnormality in the machine 200 while the power of the machine 200 is on. On the other hand, the data processing method may be executed, for example, to investigate the cause of the abnormality after the power of the machine 200 is turned off. In this case, for example, while the power of the machine 200 is on, the waveform data Wt output from the sensor 250 is stored in the memory 102 of the data processing apparatus 100, and the acquisition unit 110 may acquire the waveform data Wt stored in the memory 102 in step S110 of the data acquisition method.

[0029] The present disclosure is not limited to the above-described embodiments, and can be realized in various configurations without departing from the gist thereof. For example, the technical features in the embodiments corresponding to the technical features in each form described in the summary of the invention can be appropriately replaced or combined in order to solve part or all of the above-described problems, or to achieve part or all of the above-described effects. Further, if the technical feature is not described as essential in this specification, it can be appropriately deleted.

Explanation of Reference Numerals

[0030] 100... Data processing apparatus, 101... CPU, 102... Memory, 103... Input / output interface, 104... Internal bus, 105... Input device, 106... Display device, 110... Acquisition unit, 120... Extraction unit, 130... Determination unit, 200... Machine, 210... Actuator, 220... Control device, 250... Sensor

Claims

1. A data processing method executed by a data processing apparatus, A sensor provided in a machine including an actuator that operates according to a control mode, the method comprising an acquisition step of acquiring waveform data output from a sensor that detects a physical quantity that changes according to the operation of the actuator; An extraction step of extracting a feature amount from a predetermined extraction target section among the waveform data, the extraction step varying the length of the extraction target section according to the control mode of the actuator when the physical quantity is detected by the sensor; A data processing method having the above.

2. The data processing method according to claim 1, In the extraction step, when the control mode is a position control mode, the length of the extraction target section is made shorter than the length of the extraction target section when the control mode is not the position control mode.

3. The data processing method according to claim 2, In the extraction step, when the control mode is the position control mode, a section from the timing when the operation of the actuator starts to the timing when the operation of the actuator starts next is set as the extraction target section.

4. The data processing method according to claim 3, In the extraction step, when the control mode is not the position control mode, the entire waveform data is set as the extraction target section.

5. The data processing method according to claim 1, A data processing method having a determination step of determining the presence or absence of an abnormality of the machine using the feature amount.

6. A data processing apparatus, A sensor provided in a machine including an actuator that operates according to a control mode, the sensor acquiring waveform data output from a sensor that detects a physical quantity that changes according to the operation of the actuator. An extraction unit that extracts a feature amount from a predetermined extraction target section of the waveform data, the extraction unit varying the length of the extraction target section according to the control mode of the actuator when the physical quantity is detected by the sensor. A data processing device including the above.

Images