WO2020054496A1

WO2020054496A1 - Abnormality detecting device, method for controlling abnormality detecting device, information processing program, and recording medium

Info

Publication number: WO2020054496A1
Application number: PCT/JP2019/034520
Authority: WO
Inventors: 正善月川; 白水　岳; 克行木村
Original assignee: オムロン株式会社
Priority date: 2018-09-14
Filing date: 2019-09-03
Publication date: 2020-03-19
Also published as: JP2020045924A; JP6954247B2

Abstract

The objective of the present invention is to detect an abnormality in an actuator using a displacement time of a movable portion, irrespective of the ambient temperature and the type of actuator. An abnormality detecting device (10) determines an abnormality using characteristic values (W1 and W2), which are values obtained by subtracting minimum values (T1min and T2min) of a movement time from maximum values (T1MAX and T2MAX) thereof, and dividing the resulting values by initial values (T10 and T20) of the movement time.

Description

Anomaly detection device, control method of anomaly detection device, information processing program, and recording medium

The present invention relates to an abnormality detection device and the like for detecting an abnormality of an actuator in which a movable portion is displaced by supply of a pressure fluid.

Conventionally, there has been known an abnormality detection device that detects an abnormality of an actuator in which a movable portion is displaced by supply of a pressure fluid by using a displacement time of the movable portion. For example, Japanese Patent Application Laid-Open No. H11-163,199 discloses that a moving time of a movable part such as a piston that moves between one end and the other end of an actuator is calculated, and an actuator is calculated based on a deviation between the calculated moving time and a normal value. An abnormality detection device that determines whether an abnormality has occurred has been disclosed.

Japanese Unexamined Patent Publication "JP-A-2015-14990"

However, in the related art as described above, in order to detect the abnormality of the actuator using the deviation between the displacement time of the movable portion and the normal value, an appropriate value is set according to the temperature around the actuator, the type of the actuator, and the like. There is a problem that a normal value must be set.

That is, in general, the displacement time of the movable part is affected by the temperature around the actuator. For example, the displacement time tends to decrease as the ambient temperature increases, and the displacement time increases as the ambient temperature decreases. Tend. In addition, the displacement time of the movable part also varies depending on the type, size, purpose of use, installation location, usage time, etc. of the actuator.

Therefore, in the above-described related art, it is necessary to set a normal value for the displacement time of the movable part in consideration of factors such as the temperature around the actuator and the type of the actuator, which affect the displacement time of the movable part. is there.

One aspect of the present invention is an abnormality detection that detects an abnormality of an actuator in which a movable portion is displaced by supply of a pressure fluid, using a displacement time of the movable portion regardless of a temperature around the actuator and a type of the actuator. It is intended to realize a device or the like.

In order to solve the above problem, an abnormality detection device according to an aspect of the present invention includes an abnormality detection device that detects an abnormality of an actuator in which a movable portion is displaced by supply of a pressure fluid using a displacement time of the movable portion. Wherein, as the displacement time, a time from a time when a command for displacement to the other end is started in a state where the movable portion is at one end of the actuator to a time when the movable portion arrives at the other end. And a timer that measures the maximum value of the displacement time measured up to the present by the timer, and subtracts the minimum value of the displacement time measured up to the present by the timer, a value of the actuator. A determination unit that determines the presence or absence of an abnormality by using a characteristic amount that is a value divided by the displacement time measured by the clock unit at a time when a predetermined time has elapsed from a start time. There.

In order to solve the above problem, a control method according to an aspect of the present invention provides an abnormality detection device that detects an abnormality of an actuator in which a movable portion is displaced by supply of a pressure fluid using a displacement time of the movable portion. The control method, wherein, as the displacement time, from a time when a command for displacement to the other end is started in a state where the movable portion is at one end of the actuator, to a time when the movable portion arrives at the other end. A time counting step for measuring the time, and a value obtained by subtracting a minimum value of the displacement time measured so far in the time counting step from a maximum value of the displacement time measured up to the present time in the time counting step. At a point in time when a predetermined time has elapsed from the point in time when the actuator is activated, the presence or absence of an abnormality is determined using a feature amount that is a value divided by the displacement time measured in the timing step. And it includes a determination step.

According to one aspect of the present invention, there is an effect that an abnormality of the actuator can be detected using the displacement time of the movable portion regardless of the ambient temperature and the type of the actuator.

FIG. 1 is a block diagram illustrating a main configuration of an abnormality detection device and the like according to a first embodiment of the present invention. FIG. 2 is a diagram illustrating an outline of an abnormality detection system including the abnormality detection device of FIG. 1. It is a figure showing an example of a calculation method of “movement time of piston”. FIG. 2 is a flowchart illustrating an outline of a process executed by the abnormality detection device in FIG. 1. It is a flowchart which shows the outline of a push-out time table update process and a retraction time table update process. FIG. 6 is a diagram illustrating a relationship between a moving time and a feature amount.

[Embodiment 1]
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. In the drawings, the same or corresponding portions have the same reference characters allotted, and description thereof will not be repeated. In the present embodiment, for example, the abnormality detection device 10 will be described as a typical example of the abnormality detection device. Hereinafter, first, in order to facilitate understanding of the abnormality detection device 10, an outline of the abnormality detection system 1 including the abnormality detection device 10 will be described with reference to FIG.

§1. Application example (Overview of control system)
FIG. 2 is a diagram illustrating an outline of the abnormality detection system 1 including the abnormality detection device 10. The abnormality detection system 1 includes an abnormality detection device 10, a PLC (Programmable Logic Controller) 20, a direction switching valve 30, an actuator 40, a first switch (switch itch) 51, and a second switch 52. Contains.

The PLC 20 outputs a control signal (hereinafter also referred to as a “control command”; specifically, a Push command or a Pull command) to the direction switching valve 30 via the abnormality detection device 10, and outputs the control signal to the direction switching valve 30. The supply of the pressure fluid (for example, pressure gas) to the actuator 40 is instructed. The PLC 20 outputs a Push command or a Pull command to the direction switching valve 30 via the abnormality detection device 10, and the piston 46 and the piston rod 47 are provided between the first end 42 and the second end 43 of the cylinder 41. Are integrally reciprocated in the horizontal direction on the paper of FIG.

Specifically, in a state where the piston 46 is located at the first end 42 of the cylinder 41, the PLC 20 outputs a Push command to change the position of the piston 46 from the first end 42 to the second end 43. To be displaced. In a state in which the piston 46 is located at the second end 43 of the cylinder 41, the PLC 20 outputs a Pull command to displace the position of the piston 46 from the second end 43 to the first end 42.

The PLC 20 reciprocates the piston 46 and the piston rod 47 between the first end 42 and the second end 43 of the cylinder 41 repeatedly. In the following description, one reciprocation of the piston 46 and the piston rod 47 may be referred to as "1 Frame (frame)".

{Circle around (2)} The PLC 20 acquires the detection signal indicating the detection result of each of the first switch 51 and the second switch 52, that is, each of the first detection signal and the second detection signal via the abnormality detection device 10. In the following description and drawings, “switch” may be abbreviated as “SW”.

Further, the PLC 20 outputs a determination result of the abnormality determination from the abnormality detection device 10, that is, a signal indicating whether or not an abnormality has occurred in the actuator 40 (specifically, at least one of the piston packing 48 and the rod packing 49 has been damaged). To get.

The direction switching valve 30 can be realized by a well-known solenoid valve, acquires a control command from the PLC 20 via the abnormality detection device 10, and sends a pressure fluid to the first end of the actuator 40 according to the acquired control command. 42 or the second end 43 is selectively supplied.

For example, when the direction switching valve 30 acquires the Push command (push command), the direction switching valve 30 supplies the pressurized fluid to the first end portion 42 side of the cylinder 41 via the first port 44 and the second end portion 43 of the cylinder 41. The pressure fluid on the side is exhausted to the outside through the second port 45. Thus, the piston 46 and the piston rod 47 are integrally displaced from the first end 42 of the cylinder 41 toward the second end 43. In the following description, the displacement direction when the piston 46 and the piston rod 47 are integrally displaced to the side of the piston rod 47 where the piston 46 is not provided will be referred to as the “extrusion direction (left side in FIG. To the right). "

Further, when the direction switching valve 30 acquires the Pull command (retraction command), the direction switching valve 30 supplies the pressurized fluid to the second end 43 side of the cylinder 41 through the second port 45, and supplies the first end of the cylinder 41. The pressure fluid on the side 42 is exhausted to the outside through the first port 44. Thus, the piston 46 and the piston rod 47 are integrally displaced from the second end 43 of the cylinder 41 toward the first end 42. In the following description, the displacement direction when the piston 46 and the piston rod 47 are integrally displaced toward the side of the piston rod 47 where the piston 46 is provided is referred to as a “retraction direction (in FIG. From right to left) ".

The actuator 40 is configured such that the piston 46 (movable part) connected to the piston rod 47 is displaced in the left-right direction (displacement direction) in FIG. 2 by the supply of the pressure fluid (for example, pressure gas) from the direction switching valve 30. For example, a well-known air cylinder is used. In the actuator 40, the piston 46 connected to the piston rod 47 is displaced between the first end 42 and the second end 43 of the cylinder 41 in the left-right direction in FIG. That is, the piston 46 and the piston rod 47 move from the first end 42 of the cylinder 41 toward the second end 43 (that is, in the pushing direction) or from the second end 43 to the first end 42. (I.e., in the retraction direction), they are integrally displaced.

The actuator 40 is provided with a piston packing 48 for preventing the pressure fluid from leaking from between the cylinder 41 and the piston 46, and preventing the pressure fluid from leaking from between the cylinder 41 and the piston rod 47. And a rod packing 49.

The first switch 51 is a sensor that detects the piston 46 displaced to the first end 42 of the cylinder 41, and the second switch 52 is a sensor that detects the piston 46 displaced to the second end 43 of the cylinder 41. is there. For example, the first switch 51 is disposed on the outer peripheral surface on the first end 42 side of the cylinder 41 which is a fluid pressure cylinder constituting the actuator 40, and the second switch 52 is disposed on the second end 43 side of the cylinder 41. Is disposed on the outer peripheral surface. Each of the first switch 51 and the second switch 52 is, for example, a limit switch or a magnetic switch.

Each of the first switch 51 and the second switch 52 detects the piston 46 when the piston 46 is displaced to a position facing each of the first switch 51 and the second switch 52, and outputs a detection signal indicating that fact. Output to the abnormality detection device 10. When the piston 46 is displaced and no longer faces each of the first switch 51 and the second switch 52, each of the first switch 51 and the second switch 52 stops outputting the detection signal.

That is, the first switch 51 detects the piston 46 when the piston 46 is displaced to a position facing the first switch 51, that is, detects the piston 46 displaced to the first end 42 of the cylinder 41, The first detection signal is output to the abnormality detection device 10 (first detection signal = 1). Further, the first switch 51 stops outputting the first detection signal (first detection signal = 0) when the piston 46 is displaced and no longer faces the first switch 51.

Similarly, the second switch 52 detects the piston 46 when the piston 46 is displaced to a position facing the second switch 52, that is, detects the piston 46 displaced to the second end 43 of the cylinder 41, The second detection signal is output to the abnormality detection device 10 (second detection signal = 1). The second switch 52 stops outputting the second detection signal when the piston 46 is displaced and no longer faces the second switch 52 (the second detection signal = 0).

As shown in FIG. 2, the abnormality detection system 1 may further include an HMI 60. In the example illustrated in FIG. 2, an HMI (Human Machine Interface) 60 is connected to the PLC 20 via a communication cable such as a USB (Universal Serial Bus) cable. The HMI 60 is an information processing device for setting various parameters (particularly, parameters used by the abnormality detection device 10 and the like) to the abnormality detection system 1 and notifying (for example, displaying) the user. is there. The HMI 60 is configured by, for example, a general-purpose computer. The HMI 60 may be connected to the abnormality detection device 10.

The HMI 60 notifies the user of various information acquired from the abnormality detection device 10 via the PLC 20, and displays, for example, various information. The HMI 60 acquires the result of the abnormality determination by the abnormality detection device 10 from the abnormality detection device 10 via the PLC 20 and displays the acquired abnormality determination result. The HMI 60 moves as a difference between the “start time of the control command (Push command or Pull command)” and the “time when the piston 46 arrives at the first end 42 or the second end 43 of the cylinder 41”. The initial values of the time (T ₁₀ and T ₂₀ ) are obtained from the abnormality detection device 10. HMI60 the initial value of the movement time obtained a _{(T 10} and _{T 20),} the user editable display. HMI60 a reference value abnormality detecting device 10 is used for abnormality determination of (TH ₁ and TH _2), obtained from the abnormality detecting device 10 through the PLC 20, the acquired reference value, the user editable display.

The abnormality detection system 1 may further include a first switching sensor and a second switching sensor (not shown) that detect each of the Push command and the Pull command input to the direction switching valve 30. That is, the abnormality detection system 1 may further include a first switching sensor and a second switching sensor that detect the start of a control command (each of a Push command and a Pull command) to the direction switching valve 30.

For example, the first switching sensor is “a first solenoid that is excited by acquiring the Push command of the direction switching valve 30 and supplies a pressure fluid to the first end 42 side of the cylinder 41 via the first port 44”. And detects an input of a Push command. Specifically, the first switching sensor detects that the Push command acquired by the first solenoid changes from a low level (for example, “0”) to a high level (for example, “1”). The first switching sensor may detect, as “Push command input”, the excitation of the first solenoid by the Push command.

For example, the second switching sensor is “a second solenoid that is excited by acquiring a Pull command of the direction switching valve 30 and supplies a pressurized fluid to the second end 43 side of the cylinder 41 via the second port 45”. And detects an input of a Pull command. Specifically, the second switching sensor detects that the Pull command acquired by the second solenoid changes from a low level (for example, “0”) to a high level (for example, “1”). The second switching sensor may detect, as “pull command input”, the excitation of the second solenoid by the pull command.

The abnormality detection device 10 acquires a control command from the PLC 20, outputs the acquired control command to the directional control valve 30, and acquires and acquires a detection signal from each of the first switch 51 and the second switch 52. The detection signal is output to the PLC 20.

The abnormality detection device 10 determines the “time when the direction switching valve 30 acquires the control command” by the control command acquired from the PLC 20, that is, “displacement of the piston 46 of the actuator 40 to the direction switching valve 30 by the PLC 20 ( Start time of movement) command ”.

In addition, the abnormality detection device 10 determines, based on the detection signal acquired from each of the first switch 51 and the second switch 52, “when the piston 46 arrives at the first end 42 or the second end 43 of the cylinder 41. To get.

The abnormality detection device 10 includes “a start time of a command for the displacement (movement) of the piston 46 in the actuator 40 by the PLC 20 to the direction switching valve 30” and “the piston 46 is connected to the first end 42 or the second end of the cylinder 41. From the time when the piston 46 arrives at the second end 43 ", the movement time (displacement time) of the piston 46 is calculated.

More specifically, the abnormality detection device 10 determines that the movement of the piston 46 from the “start time of the Push command output by the PLC 20 when the piston 46 is located at the first end 42” calculating the extrusion time T ₁ is a time until the time "that arrived to the end 43. Further, the abnormality detection device 10 determines that the movement of the piston 46 from the “start time of the Pull command output by the PLC 20 when the piston 46 is located at the second end 43” to calculate the pull-back time T ₂ is the time of arrival was time "to.

The abnormality detection device 10 determines whether or not an abnormality has occurred in the actuator 40 such as breakage of at least one of the piston packing 48 and the rod packing 49 by using the calculated movement time, and sends a signal indicating the determination result to the PLC 20. Is output.

That is, the abnormality detection device 10 calculates the repetition movement time, for example, calculates each time to obtain a control command (Push command or Pull command) from the PLC 20, the moving time (extrusion time _{T 1} or pull-back time _{T 2)} I do. The abnormality detection device 10 calculates the feature amount by dividing the value obtained by subtracting the minimum value of the travel time calculated up to the present time from the maximum value of the travel time calculated so far by the initial value of the travel time. . In other words, the abnormality detection device 10 divides the value obtained by subtracting the maximum value of the travel time calculated so far by the minimum value of the travel time calculated so far by the initial value of the travel time, and calculates the feature amount. calculate. The abnormality detection device 10 determines whether or not an abnormality such as breakage of at least one of the piston packing 48 and the rod packing 49 has occurred by comparing the calculated feature amount with the reference value, and outputs a signal indicating the determination result. Output to PLC20.

Here, the movement time of the piston 46 is not stable at the initial operation point (start point) immediately after the actuator 40 is started. Therefore, the abnormality detection device 10 sets the movement time measured at the point of time when a predetermined time has elapsed (or when a predetermined number of frames have been completed after the actuator 40 has been activated) to the “initial value of the movement time”. To get as The “predetermined time (or the predetermined number of times)” used when the abnormality detection device 10 acquires the “initial value of the traveling time” may be set so that the user can operate the HMI 60 to set the “predetermined time (or the predetermined number of times)”. It may be determined at the factory shipment stage of the detection device 10. The abnormality detection device 10 acquires the “initial value of the movement time” at a point in time when a predetermined time has elapsed (or when a predetermined number of frames have been completed after the actuator 40 has been activated). The abnormality judgment based on the comparison between the amount and the reference value is started.

Further, the abnormality detection device 10 transmits the initial value of the movement time, specifically, the “initial value T ₁₀ of the extrusion time T ₁ ” and the “initial value T ₂₀ of the retraction time T ₂ ” via the PLC _20. Output to the HMI 60, and the HMI 60 displays the initial value of the movement time so that the user can edit it. The abnormality detection device 10 may display the reference value on the HMI 60 so that the user can edit the reference value.

§2. Configuration example (controller details)
FIG. 1 is a block diagram illustrating a main configuration of the abnormality detection device 10 and the like. As illustrated in FIG. 1, the abnormality detection device 10 includes, as functional blocks other than the storage unit 170, a command acquisition unit 110, a detection signal acquisition unit 120, a clock unit 130, an update control unit 140, a determination unit 150, and a notification control unit. A section 160 is provided. Note that components which are not directly related to the present embodiment are omitted from the description and block diagrams in order to ensure the simplicity of the description. However, the abnormality detection device 10 may have the omitted configuration according to the actual situation of the embodiment. Each functional block illustrated in FIG. 1 is, for example, a storage device (storage unit 170) in which a CPU (central processing unit) or the like is realized by a ROM (read only memory), an NVRAM (non-Volatile random access memory), or the like. This can be realized by reading a stored program into a RAM (random access memory) or the like (not shown) and executing it. Hereinafter, each functional block in the abnormality detection device 10 will be described.

(Details of functional blocks other than the storage unit)
The command acquisition unit 110 is a functional block that acquires control commands (Push command and Pull command) from the PLC 20 and outputs the acquired control commands to each of the direction switching valve 30 and the timer 130. 111 and a second command acquisition unit 112. The first command acquisition unit 111 acquires a Push command from the PLC 20 and outputs the acquired Push command to each of the direction switching valve 30 and the timer 130. The second command acquisition unit 112 acquires a Pull command from the PLC 20 and outputs the acquired Pull command to each of the direction switching valve 30 and the timer 130.

The detection signal acquisition unit 120 acquires the detection signals (the first detection signal and the second detection signal) from each of the first switch 51 and the second switch 52, and sends the acquired detection signals to each of the PLC 20 and the timer 130. This is a functional block to output. The detection signal acquisition unit 120 includes a first detection signal acquisition unit 121 and a second detection signal acquisition unit 122. The first detection signal acquisition unit 121 acquires the first detection signal from the first switch 51, and outputs the acquired first detection signal to each of the PLC 20 and the timer 130. The second detection signal acquisition unit 122 acquires a second detection signal from the second switch 52, and outputs the acquired second detection signal to each of the PLC 20 and the timer 130.

The timer 130 receives the control command acquired from the command acquirer 110 to indicate “the time when the direction switching valve 30 acquires the control command”, that is, “the control command for instructing the displacement (movement) of the piston 46 by the PLC 20”. Start time "is obtained. The timing unit 130 acquires “the time when the piston 46 arrives at the first end 42 or the second end 43 of the cylinder 41” based on the detection signal acquired from the detection signal acquisition unit 120. The timing unit 130 determines “the start time of the control command for instructing the displacement (movement) of the piston 46” and “the time when the piston 46 arrives at the first end 42 or the second end 43 of the cylinder 41”. Then, the movement time (displacement time) of the piston 46 is calculated. The clock unit 130 notifies the update control unit 140 of the calculated movement time (displacement time). The timer 130 includes a first timer 131 and a second timer 132.

The first timing unit 131 determines that the movement of the piston 46 from the “start time of the Push command output by the PLC 20 in the state where the piston 46 is located at the first end 42” to calculate the extrusion time T ₁ is the time of arrival to time, "he said. First time counting section 131, the calculated extrusion time _{T 1,} and notifies the update control unit 140.

The second timer 132 calculates the moving time from “the start time of the Pull command output by the PLC 20 in the state where the piston 46 is located at the second end 43” from “the piston 46 moves to the first end 42. to calculate the pull-back time T ₂ is the time of arrival to time, "he said. The second counting unit 132, the calculated pull-back time _{T 2,} and notifies the update control unit 140.

The update control unit 140 is a functional block that executes update processing of the movement time table 180 (extrusion time table update processing and retraction time table update processing) using the movement time notified from the clock unit 130. An update control unit 141 and a second update control unit 142 are included. Specifically, the update control unit 140 sets an initial value of the moving time (initial value setting), updates the maximum value of the moving time (maximum value setting), and moves the moving time table 180. The processing for updating the minimum value of time (minimum value setting) is executed.

The update control unit 140 executes the following process as a process for setting the initial value of the travel time. That is, if no initial value is stored in the movement time table 180 (the extrusion time table 181 and the retraction time table 182), the movement time notified from the timer 130 is stored in the movement time table 180 as an initial value.

The update control unit 140 executes the following two processes as a process of updating the maximum value of the travel time. That is, if the maximum value of the travel time is not stored in the travel time table 180, the update control unit 140 stores the travel time notified from the timer 130 as the maximum value of the travel time in the travel time table 180. When the value of the travel time notified from the timer 130 is larger than the maximum value of the travel time stored in the travel time table 180, the update controller 140 uses the value of the travel time notified from the timer 130 to , The maximum value of the travel time stored in the travel time table 180 is updated.

The update control unit 140 executes the following two processes as a process of updating the minimum value of the travel time. That is, if the minimum value of the travel time is not stored in the travel time table 180, the update control unit 140 stores the travel time notified from the timer 130 as the minimum value of the travel time in the travel time table 180. When the value of the travel time notified from the clock unit 130 is smaller than the minimum value of the travel time stored in the travel time table 180, the update control unit 140 uses the value of the travel time notified from the clock unit 130. , The minimum value of the travel time stored in the travel time table 180 is updated.

Due to the “processing of updating the maximum value of the movement time” executed by the update control unit 140, the movement time table 180 (the extrusion time table 181 and the retraction time table 182) is always measured by the clock unit 130 up to the present. The maximum value of the travel time is stored. By the “processing of updating the minimum value of the moving time” executed by the update control unit 140, the moving time table 180 (the extrusion time table 181 and the retraction time table 182) is always measured by the clock unit 130 up to the present. The minimum value of the moving time is stored. Hereinafter, a process of setting the initial value of the traveling time (initial value setting), a process of updating the maximum value of the traveling time (maximum value setting), and a process performed by each of the first update control unit 141 and the second update control unit 142. The process of updating the minimum value of the traveling time (minimum value setting) will be described in detail.

First update control unit 141 performs a process in which extrusion time table update processing for updating the value stored in the extrusion time table 181 using an extrusion time T _1, which is notified from the first clock section 131.

That is, if the initial value T ₁₀ of the extrusion time T ₁ is not stored in the extrusion time table 181, the first update control unit 141 replaces the extrusion time T ₁ notified from the first timer 131 with the initial value T _10. Is stored in the extrusion time table 181 (initial value setting).

If the maximum value T _1MAX of the extrusion time T ₁ is not stored in the extrusion time table 181, the first update control unit 141 sets the extrusion time T ₁ notified from the first clock unit 131 to the maximum value T _1MAX. It is stored in the time table 181 (maximum value setting). Extrusion time _{T 1,} which is notified from the first timer unit 131, the greater than the maximum value _{T 1MAX} stored in the extrusion time table 181, the first update control unit 141 is notified from the first timer unit 131 in extrusion time _{T 1,} and updates the maximum value _{T 1MAX} (maximum setting).

If the minimum value T _{1 min} of the extrusion time T ₁ is not stored in the extrusion time table 181, the first update control unit 141 sets the extrusion time T ₁ notified from the first timer 131 to the minimum value T _{1 min.} It is stored in the time table 181 (minimum value setting). The extrusion time _{T 1,} which is notified from the first timer unit 131 is smaller than the minimum value _{T 1min} stored in the extrusion time table 181, the first update control unit 141 is notified from the first timer unit 131 in extrusion time _{T 1,} and updates the minimum value _{T 1min} (minimum setting).

Second update controller 142 executes processing in a pull-back time table update processing for updating the value stored in the pull-back time table 182 by using the pull-back time T _2, which is notified from the second time measurement section 132 I do.

That is, when the pull-back time table 182 an initial value _{T 20} of pull-back time _{T 2} is not stored, the second update controller 142, pull-back time _{T 2,} which is notified from the second clock unit 132, an initial stores a value _{T 20} to pull-back time table 182 (default).

If the maximum value T _2MAX of the retraction time T ₂ is not stored in the _retraction time table 182, the second update control unit 142 sets the retraction time T ₂ notified from the second timer 132 to the maximum value T _2. _It is stored in the retraction time table 182 as _2MAX (maximum value setting). Pull-back time _{T 2} is sent from the second timer unit 132, when greater than a maximum value _{T 2MAX} stored in pull-back time table 182, the second update controller 142 notifies the second timer unit 132 in pull-back time _{T 2} that is, updates the maximum value _{T 2MAX} (maximum setting).

If the minimum value T _2min of the retraction time T ₂ is not stored in the retraction time table 182, the second update control unit 142 sets the retraction time T ₂ notified from the second timer 132 to the minimum value T _2. _It is stored in the retraction time table 182 as _{2 min} (minimum value setting). If pull-back time _{T 2} is sent from the second timer unit 132 is smaller than the minimum value _{T 2min} stored in pull-back time table 182, the second update controller 142 notifies the second timer unit 132 The minimum value T _2min is updated with the withdrawal time T ₂ (minimum value setting).

Determination unit 150 refers to the moving time table 180 (extrusion time table 181 and pull-back time table 182), the initial value of the movement time (extrusion time _{T 1} and pull-back time _{T 2),} the maximum value, and minimum calculating the amount of feature _{(W 1} and _{W 2)} with the value. Specifically, the determination unit 150 subtracts the minimum value stored in the travel time table 180 from the maximum value stored in the travel time table 180, and calculates the initial value stored in the travel time table 180. The characteristic amount is calculated by dividing by a value.

The determination unit 150 compares the calculated feature values (W ₁ and W ₂ ) with the reference values (TH ₁ and TH ₂ ) and determines whether an abnormality such as breakage of at least one of the piston packing 48 and the rod packing 49 has occurred. Determine the presence or absence.

Each of the reference value TH ₁ and the reference value TH ₂ as numeric value greater than "0", for example set by the user, are stored in the storage unit 170. The developer of the abnormality detection device 10 is obtained by repeated experiments findings, each of the reference value TH ₁ and the reference value TH ₂ is the desirably a value larger "0.5" less than "0", It is more desirable that the value be larger than “0” and equal to or smaller than “0.3”. Each of the reference value TH ₁ and the reference value TH ₂ is, for example, "0.25". The value of the reference value TH ₁ value and the reference value TH _2, may be the same numerical value, or may be different values.

The determination unit 150 notifies the notification control unit 160 of the result of the determination regarding the occurrence of the abnormality. The determination unit 150 includes a first determination unit 151 and a second determination unit 152.

The first determination unit 151 refers to the extrusion time table 181, the initial value _{T 10} of the extrusion time _{T 1,} the maximum value _{T 1MAX} extrusion time _{T 1,} and obtains the minimum value _{T 1min} extrusion time _{T 1} . The first determination unit 151 calculates the feature amount W ₁ by dividing a value obtained by subtracting the minimum value T _{1 min} from the maximum value T _1MAX by the initial value T ₁₀ , that is,

Accordingly, to calculate a feature amount _{W 1.} The first determination unit 151 compares the calculated feature quantity W ₁ and the reference value TH _1, determines the presence or absence of occurrence of an abnormality.

The first determination unit 151, the feature amount _{W 1} is greater than the reference value TH _1, the at least rod packing 49, it is determined that an abnormality such as breakage has occurred, the feature amount _{W 1,} the reference value TH ₁ In the following cases, it is determined that no abnormality has occurred. Then, the first determination unit 151 notifies the notification control unit 160 of the determination result.

When abnormality such as damage to the rod packing 49 is generated, the pressure fluid from between the cylinder 41 and the piston rod 47 from leaking to the outside of the cylinder 41, the extrusion time T ₁ is shorter (smaller). Therefore, first determination unit 151 determines the feature amount W ₁ is greater than the reference value TH _1, the at least rod packing 49, and the damage abnormality has occurred.

The second determination unit 152 refers to the pull-back time table 182, the initial value _{T 20} of pull-back time _{T 2,} the maximum value _{T 2MAX} the pull-back time _{T 2,} and the minimum value T of the pull-back time _{T 2} Acquire _{2 min} . The second determination unit 152, a value obtained by subtracting the minimum value _{T 2min} from the maximum value _{T 2MAX,} by dividing by the initial value _{T 20,} calculates the feature amount _{W 2,} that is,

Accordingly, to calculate a feature amount _{W 2.} The second determination unit 152 compares the calculated feature amount W ₂ and the reference value TH _2, determines the presence or absence of occurrence of an abnormality.

The second determination unit 152, the feature amount _{W 2} larger than the reference value TH _2, at least for piston seal 48, it is determined that an abnormality such as breakage has occurred, the feature amount _{W 2,} the reference value TH ₂ In the following cases, it is determined that no abnormality has occurred. Then, the second determination unit 152 notifies the notification control unit 160 of the determination result.

If an abnormality such as breakage occurs in the piston packing 48, the pressurized fluid leaks from between the cylinder 41 and the piston packing 48 from the second end 43 to the first end 42, so that the retraction time T2 Becomes longer (larger). Therefore, the second determination unit 152 determines the feature quantity W ₂ larger than the reference value TH _2, at least for the piston packing 48, and the damage abnormality has occurred.

Notification control section 160 outputs the determination result notified from determination section 150 (each of first determination section 151 and second determination section 152) to PLC 20. The notification control unit 160, traveling time table 180 (extrusion time table 181 and pull-back time table 182) Referring to the initial value of the movement time _{(T 10} and _{T 20),} and outputs the HMI60 via PLC20 , The initial value of the movement time is displayed on the HMI 60. Notification control unit 160 outputs the reference values (TH ₁ and TH ₂ ) to HMI 60 via PLC 20 and causes HMI 60 to display the reference values.

(Details of storage unit)
The storage unit 170 is a storage device that stores various data used by the abnormality detection device 10. The storage unit 170 includes (1) a control program, (2) an OS program, (3) an application program for executing various functions of the abnormality detection device 10, and (4) a program executed by the abnormality detection device 10. Various data to be read when the application program is executed may be temporarily stored. The above data (1) to (4) are, for example, ROM (read only memory), flash memory, EPROM (Erasable Programmable ROM), EEPROM (registered trademark) (Electrically EPROM), HDD (Hard Disc Drive), etc. Stored in a non-volatile storage device. The abnormality detection device 10 may include a temporary storage unit (not shown). The temporary storage unit is a so-called working memory that temporarily stores data used for calculation, calculation results, and the like in the course of various processes executed by the abnormality detection device 10, and is a volatile storage such as a RAM (Random Access Memory). It is composed of devices. Which data is stored in which storage device is appropriately determined based on the purpose of use, convenience, cost, physical restrictions, and the like of the abnormality detection device 10. The storage unit 170 further stores a travel time table 180.

A moving time table 180, the update control unit 140, the initial value of the movement time (extrusion time _{T 1} and pull-back time _{T 2)} _{(T 10} and _{T 20),} the maximum value _{(T 1MAX} and _{T 2MAX),} the minimum value (T _1min and T _2min ) are stored. The movement time table 180 includes an extrusion time table 181 and a retraction time table 182.

The extrusion time table 181, the first update control unit 141, the initial value _{T 10} of the extrusion time _{T 1,} the maximum value _{T 1MAX} extrusion time _{T 1,} and, the minimum value _{T 1min} extrusion time _{T 1} is stored . The pull-back time table 182, the second update controller 142, the initial value _{T 20} of pull-back time _{T 2,} the maximum value _{T 2MAX} the pull-back time _{T 2,} and the minimum value _{T 2min} of pullback time _{T 2} Is stored.

(Arrangement of abnormality detection device)
The abnormality detection device 10 whose configuration has been described with reference to FIG. 1 has been arranged as follows in order to facilitate its understanding. That is, the abnormality detection device 10 is an abnormality detection device that detects an abnormality of the actuator 40 in which the piston 46 (movable portion) is displaced by the supply of the pressurized fluid by using the movement time (displacement time) of the piston 46. It has a unit 130 and a determination unit 150. State timing unit 130, the moving time (specifically, _{T 2} Extrusion time _{T 1} and pull-back time) as, in "the first end 42 or second end 43 of the piston 46 is an actuator 40 (one end) From the time when the control command (Push command and Pull command) for the displacement to the second end 43 or the first end 42 (the other end) is started, "the piston 46 is moved to the second end 43 or the first end 42". The time until the “arrival time at the end 42” is measured. The determination unit 150 determines the minimum value of the movement time (T _1MAX and T _2MAX ) measured up to the present time by the time measurement unit 130 from the “maximum value of the movement time (T _1MAX and T _2MAX ) measured by the time measurement unit 130 up to now”. T _1min and T _2min ) ”is subtracted from the“ movement time measured by the timer 130 at the time when a predetermined time has elapsed from the activation of the actuator 40 (that is, the initial values (T ₁₀ and T ₂₀ )) ”. The presence / absence of an abnormality is determined using the feature amounts (W ₁ and W ₂ ), which are values divided by ( ₁ ).

According to the arrangement, the abnormality detecting apparatus 10, the minimum value from the maximum value _{(T 1MAX} and _{T 2MAX)} a value obtained by subtracting the _{(T 1min} and _{T 2min),} divided by the initial value _{(T 10} and _{T 20)} The presence or absence of an abnormality in the actuator 40 is determined using the feature values (W ₁ and W ₂ ) as values.

Generally, for the actuator 40 in which the piston 46 is displaced by the supply of the pressurized fluid, the moving time of the piston 46 is affected by the temperature around the actuator 40. For example, when the temperature around the actuator 40 increases, the movement time tends to decrease, and when the temperature around the actuator 40 decreases, the movement time tends to increase. The movement time also varies depending on the type of the actuator 40, the load condition, the installation position, the usage time so far, and the like.

Therefore, a conventional method of setting a normal value for the travel time in advance and comparing the measured travel time with the normal value to determine an abnormality has the following problems. That is, in order to maintain the accuracy of the abnormality determination, the conventional method has to be individually performed according to various factors such as the temperature around the actuator 40, the type of the actuator 40, the load condition, the installation position, and the usage time so far. , It is necessary to set the normal value. In other words, the conventional method corresponds to the “conditions such as the ambient temperature and the type of the actuator 40” in accordance with the moving time that varies according to “the conditions such as the ambient temperature and the type of the actuator 40”. Unless an appropriate normal value is appropriately set, the accuracy of the abnormality determination cannot be maintained.

On the other hand, the abnormality detection device 10 determines whether or not there is an abnormality in the actuator 40 by subtracting the minimum values (T _1min and T _2min ) from the maximum values (T _1MAX and T _2MAX ) to the initial values (T ₁₀ and T ₂ ). _The determination is made using the feature amounts (W ₁ and W ₂ ) which are values divided by the above ( ₂₀ ).

Here, it can be assumed that the magnitude of the change in the travel time due to a change in the ambient temperature is sufficiently smaller than the magnitude of the change in the travel time due to the occurrence of an abnormality such as a failure. That is, the magnitude of the change in the movement time due to the occurrence of the abnormality is sufficiently larger than the magnitude of the change in the movement time due to the change in the ambient temperature.

Therefore, the travel time measured at the time of occurrence of the abnormality is the maximum value of the travel time measured immediately before (that is, the time at which the abnormality did not occur and was at most affected by the change in ambient temperature). (That is, the maximum value stored in the travel time table 180) or the minimum value of the travel time measured until immediately before (that is, the minimum value stored in the travel time table 180). Become smaller. That is, when an abnormality occurs, the movement time measured at the current time (= the abnormality occurrence time) becomes the maximum value or the minimum value. In other words, the movement time is measured according to the movement time measured at the current time (= the abnormality occurrence time). The maximum value or the minimum value of the time table 180 is updated. Therefore, the occurrence of an abnormality affects the feature amount calculated using the difference between the maximum value and the minimum value of the movement time table 180. Therefore, the abnormality detection device 10 can determine whether or not an abnormality has occurred based on the feature amount calculated using the difference between the maximum value and the minimum value of the movement time table 180.

On the other hand, when the current travel time affected by the ambient temperature change is equal to or less than the maximum value of the travel time table 180 and equal to or greater than the minimum value, the maximum value and the minimum value of the travel time table 180 are determined. The feature amount using the difference of does not change depending on the current travel time. In other words, the maximum value and the minimum value of the movement time table 180 are not updated by the movement time measured at the present time, and therefore, the feature amount using the difference between the maximum value and the minimum value of the movement time table 180 does not change. . In other words, when the current travel time is equal to or less than the maximum value of the travel time table 180 and greater than or equal to the minimum value, the characteristic amount using the difference between the maximum value and the minimum value of the travel time table 180 indicates the change in the ambient temperature change. The effects are ignored.

When the current travel time affected by the ambient temperature change is larger than the maximum value of the travel time table 180 or smaller than the minimum value, the difference between the maximum value and the minimum value of the travel time table 180 is calculated. The feature amount using varies depending on the current travel time. However, the magnitude of the variation of the characteristic amount due to the influence of the surrounding temperature change is sufficiently smaller than the magnitude of the variation of the characteristic amount due to the influence of the occurrence of the abnormality. This is because the magnitude of the change in the movement time due to the change in the ambient temperature is sufficiently smaller than the magnitude of the change in the movement time due to the occurrence of an abnormality such as a failure.

Therefore, in the feature amount using the difference between the maximum value and the minimum value of the movement time table 180, the influence of the ambient temperature change should be ignored or ignored as being sufficiently small compared to the effect of the occurrence of the abnormality. Can be.

In other words, the abnormality detection device 10 changes “movement time change due to abnormality” to “movement time due to ambient temperature change” based on the feature amount using the difference between the maximum value and the minimum value in the movement time table 180. This is effective in that it can be distinguished from "fluctuations in time."

Abnormality detecting device 10, the initial value _{(T 10} and _{T 20)} by the "maximum value _{(T 1MAX} and _{T 2MAX)} and the minimum value _{(T 1min} and _{T 2min)} the difference between the" dividing by dimensionless value , A feature value used for determining abnormality of the actuator 40. That is, the abnormality detection device 10 sets a value that is not affected by the type of the actuator 40 or the like as a feature amount used for abnormality determination of the actuator 40.

The abnormality detection device 10 performs the dimensionless operation by dividing the “difference between the maximum value and the minimum value of the travel time table 180” by the initial value of the travel time table 180, thereby obtaining the “difference between the maximum value and the minimum value”. Of the actuator 40 is invalidated.

Accordingly, the abnormality detecting apparatus 10, dimensionless by dividing by the "maximum value _{(T 1MAX} and _{T 2MAX)} and the minimum value _{(T 1min} and _{T 2min)} and the difference" initial value _{(T 10} and _{T 20)} The use of the feature amount has an effect that abnormality of various types of actuators 40 can be determined with the same index.

In the abnormality detection device 10, the piston 46 is displaced in the cylinder 41 in the pushing direction or the retraction direction which is the opposite direction to the pushing direction. In the state where the piston 46 is at the first end 42 (the end on the retraction direction side) of the actuator 40, the time when the Push command (the command of the displacement in the pushing direction) is started, second end 43 measures the extrusion time T ₁ is the time until the time has arrived to (the extrusion direction side end portion) ", the determination unit 150 uses the feature amount W ₁ of the extrusion time T ₁ At least, it is determined whether there is an abnormality in the rod packing 49 for preventing the pressure fluid from leaking out from at least between the piston rod 47 connected to the piston 46 and the cylinder 41.

According to the arrangement, the abnormality detection device 10 uses the feature amount W ₁ of the extrusion time T _1, determines the presence or absence of abnormality in at least the rod packing 49. Here, if abnormality such as damage to the rod packing 49 occurs, the leak out is the pressure fluid from between the piston rod 47 and the cylinder 41, there is extrusion time T ₁ is shorter (smaller) trend. Accordingly, the abnormality detection device 10 uses the feature amount W ₁ of the extrusion time T _1, the effect of that it is possible to determine the presence or absence of abnormality in at least the rod packing 49.

In the abnormality detection device 10, the piston 46 is displaced in the cylinder 41 in the pushing direction or the retraction direction which is the opposite direction to the pushing direction. The time when the piston 46 arrives at the first end 42 of the actuator 40 from the time when the Pull command (the command for the displacement in the retraction direction) is started in the state where the piston 46 is at the second end 43 of the actuator 40. measures the pull-back time T ₂ is a time to ", the determination unit 150 uses the feature amount W ₂ of the pull-back time T _2, at least, the pressure fluid from between the piston 46 and the cylinder 41 It is determined whether there is any abnormality in the piston packing 48 for preventing leakage.

According to the arrangement, the abnormality detection device 10 uses the feature amount W ₂ of the pull-back time T _2, determines the presence or absence of abnormality in at least the piston seal 48. Here, if abnormality such as damage to the piston seal 48 occurs, from between the piston 46 and the cylinder 41 leaks out is the pressure fluid, pull-back time T ₂ becomes longer (larger) tend. Accordingly, the abnormality detection device 10 uses the feature amount W ₂ of the pull-back time T _2, the effect of that it is possible to determine the presence or absence of abnormality in at least the piston seal 48.

The abnormality detection device 10 notifies the user of the movement time (that is, the initial values (T ₁₀ and T ₂₀ )) measured by the timer 130 when a predetermined time has elapsed from the activation of the actuator 40. 160 is further provided. According to the above configuration, the abnormality detection device 10 has an effect that the user can be notified of the initial values (T ₁₀ and T ₂₀ ).

(About travel time)
3, the abnormality detection device 10 (in particular, timing unit 130) is a diagram showing an example of a calculation method by "travel time of the piston 46", specifically, extrusion time T ₁ and pull-back time T ₂ It is a figure showing an example of each calculation method. The vertical axis in FIG. 3 indicates the detection signals (first detection signal and second detection signal) from the switches (first switch 51 and second switch 52) and the commands (Push command and Pull command, respectively). Level is shown. The horizontal axis in FIG. 3 indicates time (Time), and the unit is ms (millisecond).

(About extrusion time)
As illustrated in FIG. 3, for example, as illustrated in FIG. 3, the Level of the Push command is set to “the start time of the Push command output by the PLC 20 when the piston 46 is located at the first end 42. The time at which the value changes from "0 (low)" to "1 (high)" is detected. The first timer 131 sets the time at which the Push command is notified from the first command acquisition unit 111 as "the start time of the Push command output by the PLC 20 when the piston 46 is located at the first end 42". May be detected. In other words, the first timing unit 131 may detect a time at which the level of the Push command notified from the first command acquisition unit 111 changes from “0 (low)” to “1 (high)”. In addition, the first time measurement unit 131 determines that the first command acquisition unit 111 sends the direction switching valve 30 a “start time of the Push command output by the PLC 20 when the piston 46 is located at the first end 42”. The time at which the Push command is output may be detected. In other words, the first timing unit 131 detects the time at which the level of the Push command output from the first command acquisition unit 111 to the direction switching valve 30 changes from “0 (low)” to “1 (high)”. Is also good.

As shown in FIG. 3, for example, as illustrated in FIG. 3, the Level of the second detection signal from the second switch 52 is set to “0 (low)” as the “time when the piston 46 arrives at the second end 43”. ”To“ 1 (high) ”. The first timing unit 131 determines the time at which the second detection signal was notified from the second detection signal acquisition unit 122 (or the second detection signal acquisition unit) as “the time when the piston 46 arrived at the second end 43”. 122 may acquire the second detection signal). In other words, the first timing unit 131 sets the Level of the second detection signal notified from the second detection signal acquisition unit 122 (or acquired by the second detection signal acquisition unit 122 from the second switch 52) to “0 ( The time at which the “low)” changes to “1 (high)” may be detected.

First time counting portion 131, the extrusion time _{T 1,} as shown in FIG. 3, from "in a state where the piston 46 is positioned at the first end portion 42, the start time of the Push command PLC20 outputs", " Until the piston 46 arrives at the second end 43 ”.

(About withdrawal time)
As illustrated in FIG. 3, for example, as illustrated in FIG. 3, the level of the Pull command is set to “the start time of the Pull command output from the PLC 20 when the piston 46 is located at the second end 43. The time at which the value changes from "0 (low)" to "1 (high)" is detected. The second timer 132 determines the time when the Pull command was notified from the second command acquisition unit 112 as “the start time of the Pull command output by the PLC 20 when the piston 46 is located at the second end 43”. May be detected. In other words, the second timing unit 132 may detect a time when the level of the Pull command notified from the second command acquisition unit 112 changes from “0 (low)” to “1 (high)”. In addition, the second time counting unit 132 determines that the second command acquisition unit 112 sends the direction switching valve 30 a “start time of the Pull command output by the PLC 20 when the piston 46 is located at the second end 43”. The time at which the Pull command is output may be detected. In other words, the second timing unit 132 detects the time when the level of the Pull command output from the second command acquisition unit 112 to the direction switching valve 30 changes from “0 (low)” to “1 (high)”. Is also good.

As shown in FIG. 3, for example, as shown in FIG. 3, the Level of the first detection signal from the first switch 51 is set to “0 (low)” as the “time when the piston 46 arrives at the first end 42”. ”To“ 1 (high) ”. The second timer 132 determines the time when the first detection signal was notified from the first detection signal acquisition unit 121 (or the first detection signal acquisition unit) as “the time when the piston 46 arrived at the first end 42”. 121 may detect the first detection signal). In other words, the second timing unit 132 sets the Level of the first detection signal notified from the first detection signal acquisition unit 121 (or acquired by the first detection signal acquisition unit 121 from the first switch 51) to “0 ( The time at which the “low)” changes to “1 (high)” may be detected.

The second counting unit 132, a pull-back time _{T 2,} as shown in FIG. 3, from "in a state where the piston 46 is positioned in the second end portion 43, the start time of the Pull command PLC20 outputs" It is calculated as the time until "the time when the piston 46 arrives at the first end 42".

§3. Example of operation (Overview of the process executed by the abnormality detection device)
FIG. 4 is a flowchart illustrating an outline of a process executed by the abnormality detection device 10. The command acquisition unit 110 acquires control commands (Push command and Pull command) from the PLC 20, that is, the first command acquisition unit 111 acquires a Push command, and the second command acquisition unit 112 acquires a Pull command. (S110). The command acquisition unit 110 notifies the time control unit 130 of the acquired control command, that is, the first command acquisition unit 111 notifies the push command to the time measurement unit 130, and the second command acquisition unit 112 measures the Pull command. Notify section 130.

The detection signal acquisition unit 120 acquires a detection signal (first detection signal and second detection signal) from each of the first switch 51 and the second switch 52. That is, the first detection signal acquisition unit 121 acquires the second detection signal from the second switch 52, and the second detection signal acquisition unit 122 acquires the first detection signal from the first switch 51 (S120). . The detection signal acquisition unit 120 notifies the time detection unit 130 of the acquired detection signal, that is, the first detection signal acquisition unit 121 notifies the time detection unit 130 of the second detection signal, and the second detection signal acquisition unit 122 Notifies the timer 130 of the first detection signal.

The timer 130 calculates “the start time of the control command for instructing the movement of the piston 46” based on the control command (Push command and Pull command) notified from the command acquisition unit 110. In addition, the timing unit 130 determines that the “piston 46 has arrived at the first end 42 or the second end 43” based on the detection signals (the first detection signal and the second detection signal) notified from the detection signal acquisition unit 120. At the time when it was done ". The timer 130 calculates the movement time (from the “start time of the control command instructing the movement of the piston 46” and the “time when the piston 46 arrives at the first end 42 or the second end 43”). extrusion time _{T 1} and pull-back time _{T 2)} is calculated.

That is, the first timing unit 131 determines that the “piston 46 has arrived at the second end 43 from the“ start time of the Push command output by the PLC 20 when the piston 46 is located at the first end 42 ”. calculating the extrusion time T ₁ is a time until the time ". The second timer 132 calculates the time at which the piston 46 arrives at the first end 42 from the “start time of the Pull command output by the PLC 20 when the piston 46 is located at the second end 43”. Is calculated (S130). Timing unit 130 (first timing unit 131, and a second timer unit 132) the calculated travel time (the extrusion time _{T 1} and pull-back time _{T 2),} and notifies the update control unit 140.

The update control unit 140 executes an update process of the movement time table 180, that is, the first update control unit 141 executes an extrusion time table update process, and the second update control unit 142 executes a retraction time table update process. (S140). Details of the push-out time table updating process and the pull-back time table updating process will be described later with reference to FIG.

Determination unit 150 refers to the moving time table 180 (extrusion time table 181 and pull-back time table 182), the initial value of the movement time (extrusion time _{T 1} and pull-back time _{T 2),} the maximum value, and minimum calculating the amount of feature _{(W 1} and _{W 2)} with the value.

That is, the first determination unit 151 refers to the extrusion time table 181 and _divides the value obtained by subtracting the minimum value T _{1 min} from the maximum value T _1MAX by the initial value T ₁₀ using Expression 1, that is, by dividing the value by the initial value T ₁₀ . to calculate the amount _{W 1.} The second determination unit 152 refers to the pull-back time table 182, according to Equation 2, i.e., a value obtained by subtracting the minimum value _{T 2min} from the maximum value _{T 2MAX,} by dividing by the initial value _{T 20,} feature amount W ₂ to calculate the (S150).

The determination unit 150 compares the calculated feature values (W ₁ and W ₂ ) with the reference values (TH ₁ and TH ₂ ) to determine whether an abnormality such as breakage of the actuator 40 has occurred (S160).

That is, when the first determination unit 151 confirms that the feature amount W ₁ is equal to or smaller than the reference value TH ₁ (Yes in S160), the first determination unit 151 determines that no abnormality has occurred, and sends the determination result to the notification control unit 160. Notice. The notification control unit 160 notifies the PLC 20 of the determination result that "there is no abnormality" notified from the first determination unit 151 (S170).

The first determination unit 151, the feature amount _{W 1} to confirm larger than the reference value TH ₁ (No in S160), for at least rod packing 49, it is determined that an abnormality such as breakage has occurred, the determination The result is notified to the notification control unit 160. The notification control unit 160 notifies the PLC 20 of the determination result notified from the first determination unit 151 that "at least the rod packing 49 has an abnormality such as breakage" (S180).

The second determination unit 152 confirms that the feature quantity _{W 2} is the reference value TH ₂ or less (Yes in S160), the abnormality is determined not to have occurred, and notifies the determination result to the notification control section 160 . The notification control unit 160 notifies the PLC 20 of the result of the determination that “there is no abnormality” notified from the second determination unit 152 (S170).

The second determination unit 152, the feature amount _{W 2} confirms larger than the reference value TH ₂ (No at S160), for at least the piston seal 48, it is determined that an abnormality such as breakage has occurred, the determination The result is notified to the notification control unit 160. The notification control unit 160 notifies the PLC 20 of the determination result notified from the second determination unit 152 that "at least an abnormality such as breakage has occurred in the piston packing 48" (S180).

The “processing executed by the abnormality detection device 10” described so far with reference to FIG. 4 can be organized as follows. In other words, the “processing performed by the abnormality detection device 10” includes abnormality detection in which the abnormality of the actuator 40 in which the piston 46 (movable part) is displaced by the supply of the pressure fluid is detected using the movement time (displacement time) of the piston 46. This is a control method of the device, which includes a time counting step (S130) and a determining step (S160). In the timing step (S < _b > 130), the movement time (specifically, the extrusion time T < _b > ₁ and the retraction time T < _b > ₂ ) is set as “the piston 46 is the first end 42 or the second end 43 (one end) of the actuator 40. From the time when the control command (Push command and Pull command) for the displacement to the second end 43 or the first end 42 (the other end) is started, the piston 46 is moved from the second end 43 to the second end 43. Alternatively, the time until "the time when the vehicle arrives at the first end 42" is measured. The determination step (S160) is based on “the maximum value of the movement time (T _1MAX and T _2MAX ) measured up to the present time in the timing step (S130)” and “measured up to the present time in the timing step (S130)”. The minimum value of the moving time (T _{1 min} and T _{2 min} ) ”is subtracted from the moving time measured in the clocking step (S 130) at the time when a predetermined time has elapsed from the time of activation of the actuator 40 (that is, The presence / absence of an abnormality is determined using the feature amounts (W ₁ and W ₂ ) that are values divided by the “initial values (T ₁₀ and T ₂₀ ))”.

According to the method, the control method, the maximum value _{(T 1MAX} and _{T 2MAX)} minimum value of the value obtained by subtracting the _{(T 1min} and _{T 2min),} a value obtained by dividing by the initial value _{(T 10} and _{T 20)} The presence / absence of abnormality in the actuator 40 is determined using the characteristic amounts (W ₁ and W ₂ ).

In contrast, the control method, the presence or absence of abnormality of the actuator 40, the minimum value from the maximum value _{(T 1MAX} and _{T 2MAX)} a value obtained by subtracting the _{(T 1min} and _{T 2min),} the initial value _{(T 10} and T _The determination is made using the feature amounts (W ₁ and W ₂ ) which are values divided by the above ( ₂₀ ).

That is, the control method uses the feature amount using the difference between the maximum value and the minimum value of the movement time table 180 to change “movement time change due to abnormality” to “movement time change due to ambient temperature change”. The effect is that it can be grasped separately from "fluctuations of".

The control method includes an initial value _{(T 10} and _{T 20)} by the "maximum value _{(T 1MAX} and _{T 2MAX)} and the minimum value _{(T 1min} and _{T 2min)} difference between" a value obtained by dividing by dimensionless, The feature amount is used for determining the abnormality of the actuator 40. That is, in the control method, a value that is not affected by the type of the actuator 40 or the like is used as a feature amount used for determining an abnormality of the actuator 40.

The control method divides the “difference between the maximum value and the minimum value of the travel time table 180” by the initial value of the travel time table 180 to make the dimensionless, thereby obtaining the “difference between the maximum value and the minimum value”. Of the actuator 40 is invalidated.

Accordingly, the control method, "maximum value _{(T 1MAX} and _{T 2MAX)} and the minimum value _{(T 1min} and _{T 2min)} and the difference between the" features dimensionless by dividing the the initial value _{(T 10} and _{T 20)} The use of the quantity has the effect that abnormality of various types of actuators 40 can be determined with the same index.

(Extrusion time table update processing and pullback time table update processing)
FIG. 5 is a flowchart showing an outline of the push-out time table update process and the pull-back time table update process executed by the abnormality detection device 10. The push-out time table update process is executed by the first update control unit 141, and the withdrawal time table update process is executed by the second update control unit 142.

The update control unit 140 refers to the travel time table 180 to determine whether the initial value has been stored. That is, the first update control unit 141 determines whether or not the initial value T ₁₀ has been stored in the extrusion time table 181, and the second update control unit 142 has stored the initial value T ₂₀ in the pullback time table 182. Is determined (S1410).

If it is confirmed that the initial value is not stored in the travel time table 180 (No in S1410), the update control unit 140 stores the travel time calculated by the timer 130 as the initial value in the travel time table 180. That is, when confirming that the initial value T ₁₀ is not stored in the extrusion time table 181, the first update control unit 141 stores the extrusion time T ₁ calculated by the first timer 131 in the extrusion time table 181. stores a value _{T 10} (S1420). Further, when it is confirmed that the initial value _{T 20} to pull-back time table 182 is not stored, the second update controller 142, a pull-back time _{T 2} the calculated second clock section 132, pull-back time table 182 to be stored as an initial value _{T 20} (S1420).

The update control unit 140 determines whether “the movement time calculated by the timer 130 is equal to or less than the maximum value stored in the movement time table 180”. That is, the first update control unit 141 determines "whether first calculated extrusion time _{T 1} of the timer unit 131 is less than or equal to the maximum value _{T 1MAX} stored in the extrusion time table 181" (S1430). The second update controller 142 determines "pull-back time _{T 2} the calculated second time measurement section 132, or less than the maximum value _{T 2MAX} stored in pull-back time table 182," a (S1430 ).

When the maximum value is not stored in the travel time table 180, the update control unit 140 determines that “the travel time calculated by the timer 130 is not less than or equal to the maximum value stored in the travel time table 180 (for example, the maximum value Greater). That is, when the maximum value T _1MAX is not stored in the extrusion time table 181, the first update control unit 141 determines that “the extrusion time T ₁ calculated by the first timer 131 is stored in the extrusion time table 181. It is not less than the maximum value _T1MAX ". The storage, when the maximum value _{T 2MAX} the pull-back time table 182 is not stored, the second update controller 142, the "pull-back time _{T 2} the calculated second time measuring section 132, pull-back time table 182 Is not less than or equal to the maximum value _T2MAX that has been set.

If it is determined that “the traveling time calculated by the clock unit 130 is larger than the maximum value stored in the traveling time table 180” (No in S1430), the update control unit 140 uses the traveling time calculated by the clock unit 130 to calculate The maximum value of the movement time table 180 is updated. That is, when it is determined that "calculated extrusion time _{T 1} of the first time counting unit 131 is greater than the maximum value _{T 1MAX} stored in the extrusion time table 181" (No in S1430), the first update control unit 141, Perform the following processing. That is, the first update control unit 141, the calculated extrusion time _{T 1} of the first time counting unit 131 updates the maximum value _{T 1MAX} extrusion time table 181 (S1440). Further, "pull-back time _{T 2} the calculated second time counting unit 132 is greater than the maximum value _{T 2MAX} stored in pull-back time table 182" (No in S1430) If it is determined that the second update controller 142 Performs the following processing. That is, the second update controller 142 by pull-back time _{T 2} the calculated second time counting unit 132 updates the maximum value _{T 2MAX} the pull-back time table 182 (S1440).

When the maximum value T _1MAX is not stored in the extrusion time table 181, the first update control unit 141 stores the extrusion time T ₁ calculated by the first timer 131 as the maximum value T _1MAX in the extrusion time table 181. I do. Also, when the maximum value _{T 2MAX} the pull-back time table 182 is not stored, the second update controller 142, a pull-back time _{T 2} the calculated second time counting unit 132, a pull-back time table 182, the maximum _Stored as value _T2MAX .

The update control unit 140 determines whether “the movement time calculated by the timer 130 is equal to or more than the minimum value stored in the movement time table 180”. That is, the first update control unit 141 determines "whether calculated extrusion time _{T 1} of the first time counting unit 131 is the minimum value _{T 1min} or stored in the extrusion time table 181" (S1450). The second update controller 142 determines "pull-back time _{T 2} the calculated second time counting unit 132, whether the minimum value _{T 2min} or stored in pull-back time table 182," a (S1450 ).

If the minimum value is not stored in the travel time table 180, the update control unit 140 determines that “the travel time calculated by the timer 130 is not equal to or greater than the minimum value stored in the travel time table 180 (for example, the maximum value Is smaller). That is, when the minimum value T _{1 min} is not stored in the extrusion time table 181, the first update control unit 141 determines that “the extrusion time T ₁ calculated by the first timer 131 is stored in the extrusion time table 181. Not more than the minimum value T _{1 min} ". If the minimum value T _2min is not stored in the pull-back time table 182, the second update control unit 142 determines that “the pull-back time T ₂ calculated by the second timer 132 is stored in the pull-back time table 182. It is not more than the minimum value T _{2 min} . "

When it is determined that “the traveling time calculated by the timer 130 is smaller than the minimum value stored in the traveling time table 180” (No in S1450), the update controller 140 calculates The minimum value of the movement time table 180 is updated. That is, when it is determined that "calculated extrusion time _{T 1} of the first time counting unit 131, the minimum value _{T 1min} smaller than that stored in the extrusion time table 181" (No in S1450), the first update control unit 141, Perform the following processing. That is, the first update control unit 141 updates the minimum value T _{1 min} of the extrusion time table 181 with the extrusion time T ₁ calculated by the first clock unit 131 (S1460). Further, "pull-back time _{T 2} the calculated second time counting unit 132, the minimum value _{T 2min} smaller than that stored in the pull-back time table 182" (No in S1450) If it is determined that the second update controller 142 Performs the following processing. That is, the second update controller 142 by pull-back time _{T 2} the calculated second time counting unit 132, and updates the minimum value _{T 2min} of pullback time table 182 (S1460).

When the minimum value T _{1 min} is not stored in the extrusion time table 181, the first update control unit 141 stores the extrusion time T ₁ calculated by the first timer 131 as the minimum value T _{1 min} in the extrusion time table 181. I do. When the minimum value T _{2 min} is not stored in the retraction time table 182, the second update control unit 142 stores the retraction time T ₂ calculated by the second timer 132 in the reversion time table 182 in the minimum value. It is stored as the value T _2min .

(Relationship between travel time and feature value)
Figure 6 is a diagram showing the relationship between the moving time and the feature amount, particularly showing the relationship between the pull-back time T ₂ and the feature quantity W _2. The relationship between the extrusion time T ₁ and the feature amount W _1, the same as shown in FIG. The horizontal axis in FIG. 6 indicates the number of reciprocations (Frame number) of the piston 46 and the piston rod 47, and the vertical axis indicates the retraction time T ₂ (value) on the left side of the paper, and the unit is μs. (Μsec). The vertical axis on the right side of the paper indicates the feature amount. Hereinafter, the relationship between the movement time and the feature amount will be described with reference to FIG. 6, and the influence on the movement time due to the temperature around the actuator 40 and the influence on the movement time due to an abnormality such as a failure of the actuator 40. The distinction will be described.

(Effects on travel time due to changes in ambient temperature)
In the actuator 40, the pressure fluid (for example, pressure gas) supplied from the direction switching valve 30 thermally expands, and the cylinder 41, the piston 46, and the like also thermally expand. Affected by temperature. That is, as shown in FIG. 6, even at the stage of abnormal such as a failure in the actuator 40 has not occurred, the movement time of the piston 46 (movable portion) is (displacement time) pull-back time T _{2 (Extrusion} time T ₁₎ Fluctuates depending on the temperature around the actuator 40.

Under the condition that the temperature around the actuator 40 does not change, that is, under constant temperature conditions, it is possible to monitor only the movement time of the piston 46 and detect an abnormality such as breakage of the actuator 40. The temperature around the actuator 40 changes. Under conditions in which the temperature around the actuator 40 changes due to the date and time, the season, the operating status of the device around the actuator 40, etc., whether the movement time of the piston 46 fluctuates due to a change in the surrounding temperature, It cannot be distinguished whether it is due to a failure or other abnormality.

Under the condition that the “variation amount Der of the movement time due to the abnormality” is larger than the “variation amount Dte of the movement time due to the change in ambient temperature”, the abnormality detection device 10 sets the characteristic amount of the movement time. By using W ₂ (W ₁ ), the variation Der and the variation Dte are distinguished. The abnormality detection device 10 uses the difference between the maximum value and the minimum value of the traveling time measured during the measurement period, that is, the time measured from the start of the abnormality determination to the present time, as the feature amount, thereby obtaining the variation amount. Der is distinguished from the variation Dte. Hereinafter, the reason why the fluctuation amount Der and the fluctuation amount Dte can be distinguished will be described in detail.

(6) As shown in FIG. 6, the “movement time fluctuation amount Der due to abnormality” is sufficiently larger than the “movement time fluctuation amount Dte due to ambient temperature change”. In the feature amount calculated using the difference between the maximum value and the minimum value of the moving time, the variation amount Dte is negligibly small, while the variation amount Der is sufficiently large.

That is, the movement time measured when an abnormality such as a failure of the actuator 40 occurs becomes larger than the maximum value of the movement time measured before the occurrence of the abnormality because the variation Der is sufficiently large. It becomes smaller than the minimum value of the movement time measured before the occurrence. Therefore, when an abnormality occurs, the maximum value or the minimum value of the traveling time is updated by the traveling time measured when the abnormality occurs, that is, updated by the traveling time measured at the time of occurrence of the abnormality (= current time). Is done. Since the fluctuation amount Der is sufficiently large, the “value obtained by subtracting the minimum value from the maximum value” after the update is the “value obtained by subtracting the minimum value from the maximum value” before the update (that is, before the occurrence of the abnormality). In comparison, it is large enough. That is, the “variation amount Der of the traveling time due to the abnormality” is not ignored even in the feature amount calculated using the difference between the maximum value and the minimum value of the traveling time.

On the other hand, in the feature amount calculated using the difference between the maximum value and the minimum value of the traveling time, the “variation amount Dte of the traveling time due to a change in ambient temperature” is sufficiently small and should be ignored. Can be.

For example, the travel time measured at the present time (the travel time obtained by adding the variation Dte to the travel time that would be measured under constant temperature conditions) is less than or equal to the maximum value up to the present time and greater than or equal to the minimum value. , The maximum value and the minimum value are not updated by the current travel time. Therefore, the feature amount calculated using the difference between the maximum value and the minimum value of the movement time does not change, that is, the change amount Dte is ignored in the feature amount.

Further, even when the maximum value or the minimum value is updated by the moving time at the current time to which the fluctuation amount Dte is added, for the feature amount calculated using the difference between the maximum value and the minimum value of the moving time, The variation between before and after the update is small enough. That is, when the maximum value or the minimum value is updated by the movement time to which the variation Dte is added, the variation of the feature value before and after the update is such that the maximum value or the minimum value depends on the movement time to which the variation Der is added. This is sufficiently small compared to the variation in the feature value before and after the update in the case of updating. This is because the “movement time variation Der due to abnormality” is sufficiently larger than the “movement time variation Dte due to ambient temperature change”.

Therefore, by setting an appropriate reference value TH ₂ (TH ₁ ), it is possible to ignore the variation in the feature amount due to the addition of the variation amount Dte and to grasp only the variation in the feature amount due to the addition of the variation amount Der. That is, in the feature amount calculated using the difference between the maximum value and the minimum value of the movement time, the effect of the variation Der can be reliably grasped while ignoring the effect of the variation Dte. The abnormality detection device 10 determines “variation in travel time due to abnormality” by “characteristic amount calculated using the difference between the maximum value and minimum value of travel time” as “moving time due to ambient temperature change”. Fluctuations ".

(Relationship between actuator type and travel time)
The movement time (displacement time) of the piston 46 (movable part) differs depending on the type of the actuator 40, such as the diameter and length of the cylinder 41, and also depends on the load condition of the actuator 40.

Therefore, the abnormality detection device 10 determines the dimensionless value by dividing the “difference between the maximum value and the minimum value of the movement time” by the “initial value of the movement time”, that is, the influence of the type of the actuator 40 and the like. A value that is not received is set as a feature amount used for determining abnormality of the actuator 40. By dividing the “difference between the maximum value and the minimum value of the travel time” by the “initial value of the travel time” to make it non-dimensional, the abnormality detection device 10 obtains the “difference between the maximum value and the minimum value of the travel time” Of the actuator 40 is invalidated.

The abnormality detection device 10 uses the feature amount, which is a dimensionless value obtained by dividing the “difference between the maximum value and the minimum value of the travel time” by the “initial value of the travel time”, as an index used for abnormality determination. Accordingly, various types of abnormalities of the actuator 40 can be determined with the same index.

§4. Modification (Acquisition of start time of control command)
It is not essential for the abnormality detection device 10 to acquire each of the Push command and the Pull command from the PLC 20. The abnormality detection device 10 only needs to be able to acquire the time when the direction switching valve 30 acquires each of the Push command and the Pull command. For example, in the direction switching valve 30, sensors (not shown) (a first switching sensor and a second switching sensor) are provided for each of a first solenoid that acquires a Push command and a second solenoid that acquires a Pull command. Then, each of the first switching sensor and the second switching sensor is caused to detect "acquiring each of the Push command and the Pull command by each of the first solenoid and the second solenoid". The abnormality detection device 10 may acquire the time when the direction switching valve 30 acquires each of the Push command and the Pull command from the detection results of the first switching sensor and the second switching sensor. That is, the abnormality detection device 10 may acquire the time when the level of the Push command changes from “0 (low)” to “1 (high)” from the detection result of the first switching sensor. The abnormality detection device 10 may acquire the time when the level of the Pull command changes from “0 (low)” to “1 (high)” from the detection result of the second switching sensor.

(About the configuration of the abnormality detection system)
The configuration in which the PLC 20 is connected to each of the direction switching valve 30, the first switch 51, and the second switch 52 via the abnormality detection device 10 has been described above. It is not essential for each of the detection device 10 and the PLC 20. The PLC 20 may be directly connected to each of the direction switching valve 30, the first switch 51, and the second switch 52. The abnormality detection device 10 is connected to each of the direction switching valve 30 (or each of the first switching sensor and the second switching sensor), the first switch 51, and the second switch 52 via the PLC 20. Is also good.

For example, a configuration may be adopted in which the abnormality detection device 10 is connected to each of the direction switching valve 30, the first switch 51, and the second switch 52 via the PLC 20. The abnormality detecting device 10 outputs the time when the level of the Push command changes from “0 (low)” to “1 (high)” from the PLC 20 and the level of the Pull command from “0 (low)” to “1 (high)”. )) May be acquired. The abnormality detecting device 10 sets the time when the level of the second detection signal changes from “0 (low)” to “1 (high)” and the level of the first detection signal via the PLC 20 to “0 (low)”. , The time when the time changes from “1” to “1 (high)” may be acquired.

(About the configuration of the abnormality detection device)
So far, an example has been described in which the abnormality detection device 10 and the PLC 20 are separate devices. However, it is not essential that the abnormality detection device 10 be configured as a device independent of the PLC 20. It may be configured as an integrated device with the PLC 20.

[Example of software implementation]
The control blocks (in particular, the command acquisition unit 110, the detection signal acquisition unit 120, the clock unit 130, the update control unit 140, the determination unit 150, and the notification control unit 160) of the abnormality detection device 10 include an integrated circuit (IC chip) and the like. May be realized by a logic circuit (hardware) formed in the computer, or may be realized by software using a CPU (CenTral Processing Unit).

In the latter case, the abnormality detection device 10 includes a CPU that executes instructions of a program that is software for realizing each function, a ROM (Read Only Memory) in which the program and various data are recorded so as to be readable by a computer (or CPU). Alternatively, a storage device (these are referred to as “recording media”), a RAM (Random Access Memory) for expanding the program, and the like are provided. Then, the object of the present invention is achieved when the computer (or CPU) reads the program from the recording medium and executes the program. As the recording medium, a “temporary tangible medium”, for example, a tape, a disk, a card, a semiconductor memory, a programmable logic circuit, or the like can be used. 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 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 abnormality detection device according to an aspect of the present invention is an abnormality detection device that detects an abnormality of an actuator whose movable portion is displaced by supply of a pressure fluid using a displacement time of the movable portion, wherein the displacement time is A timing unit that measures a time from a time when a displacement command to the other end is started in a state where the movable unit is at one end of the actuator to a time when the movable unit arrives at the other end; From the maximum value of the displacement time measured so far by the unit, the value obtained by subtracting the minimum value of the displacement time measured so far by the time counting unit, at the time when a predetermined time has elapsed from the start time of the actuator A determination unit that determines whether there is an abnormality using a feature amount that is a value divided by the displacement time measured by the clock unit.

According to the configuration, the abnormality detection device divides a value obtained by subtracting a minimum value from a maximum value of the displacement time measured up to the present time by the displacement time measured at a time when a predetermined time has elapsed from the start time. The presence / absence of an abnormality in the actuator is determined by using the feature value which is the obtained value.

Generally, for an actuator in which the movable part is displaced by the supply of a pressure fluid, the displacement time of the movable part is affected by the temperature around the actuator. For example, when the temperature around the actuator increases, the displacement time tends to decrease, and when the temperature around the actuator decreases, the displacement time tends to increase. Further, the displacement time also varies depending on the type of the actuator, load conditions, installation position, usage time so far, and the like.

Therefore, a conventional method of setting a normal value for the displacement time in advance and comparing the measured displacement time with a normal value to determine an abnormality has the following problems. In other words, in order to maintain the accuracy of the abnormality determination, the conventional method is individually performed according to various factors such as the temperature around the actuator, the type of the actuator, the load condition, the installation position, and the usage time so far. , It is necessary to set the normal value. In other words, the conventional method is based on the “conditions such as the ambient temperature and the type of the actuator” in accordance with the displacement time that varies according to “the conditions such as the ambient temperature and the type of the actuator”. Unless an appropriate normal value is appropriately set, the accuracy of the abnormality determination cannot be maintained.

On the other hand, the abnormality detection device determines whether or not the actuator has an abnormality by determining whether or not a value obtained by subtracting a minimum value from a maximum value of the displacement time measured up to the present time at a predetermined time from the start time. The value is divided by the measured displacement time ".

Here, it can be assumed that the magnitude of the change in the displacement time due to a change in the ambient temperature is sufficiently smaller than the magnitude of the change in the displacement time due to the occurrence of an abnormality such as a failure. That is, the magnitude of the change in the displacement time due to the occurrence of the abnormality is sufficiently larger than the magnitude of the change in the displacement time due to the change in the ambient temperature.

Therefore, the displacement time measured at the time of occurrence of the abnormality is the time of the displacement time measured immediately before (that is, the occurrence of the abnormality, which is at most affected only by the change in ambient temperature). It becomes larger than the maximum value or becomes smaller than the minimum value of the displacement time measured immediately before. That is, when an abnormality occurs, the displacement time measured at the current time point (= the abnormality occurrence time point) becomes the maximum value or the minimum value, and the feature amount calculated using the difference between the maximum value and the minimum value. The occurrence of an abnormality affects the Therefore, the abnormality detection device can determine whether an abnormality has occurred based on the feature amount calculated using the difference between the maximum value and the minimum value.

On the other hand, when the current displacement time affected by the ambient temperature change is equal to or less than the maximum value and equal to or greater than the minimum value, the difference between the maximum value and the minimum value is used. The amount does not vary with the current displacement time. That is, when the current displacement time is equal to or less than the maximum value and equal to or greater than the minimum value, the influence of the ambient temperature change is ignored in the feature amount using the difference between the maximum value and the minimum value. .

In addition, the current displacement time affected by the ambient temperature change is larger than the maximum value, or, if smaller than the minimum value, the feature amount using a difference between the maximum value and the minimum value, It fluctuates according to the current displacement time affected by the ambient temperature change. However, the magnitude of the variation of the feature quantity due to the influence of the ambient temperature change is sufficiently smaller than the magnitude of the variation of the feature quantity due to the influence of the abnormality. This is because the magnitude of the change in the displacement time due to a change in the ambient temperature is sufficiently smaller than the magnitude of the change in the displacement time due to the occurrence of an abnormality such as a failure.

Therefore, in the feature value using the difference between the maximum value and the minimum value, the influence of the ambient temperature change can be neglected or can be ignored as being sufficiently small as compared with the influence of the occurrence of the abnormality. .

In other words, the abnormality detection device determines, based on the feature amount using the difference between the maximum value and the minimum value, the “fluctuation in the displacement time due to the abnormality” and the “displacement due to the ambient temperature change. This is effective in that it can be distinguished from "fluctuations in time."

The abnormality detection device is dimensionless by dividing the “difference between the maximum value and the minimum value” by the “displacement time measured at the time when a predetermined time has elapsed from the start time (that is, the initial value)”. Let the value be the characteristic amount used for the abnormality determination of the actuator. That is, the abnormality detection device sets a value that is not affected by the type of the actuator or the like as the feature amount used for the abnormality determination of the actuator.

The anomaly detection device, by dividing the “difference between the maximum value and the minimum value” by the “initial value” to make the dimensionless, the “difference between the maximum value and the minimum value” And the effect of the type of the actuator and the like is nullified.

Therefore, the anomaly detection device uses the same dimension as the non-dimensional feature amount by dividing the “difference between the maximum value and the minimum value” by the “initial value”. There is an effect that it is possible to determine the type of abnormality of the actuator.

In the abnormality detection device according to one aspect of the present invention, the movable portion is displaced in the cylinder in a pushing direction, or in a retraction direction that is a direction opposite to the pushing direction, and the timing section is configured as the displacement time. From the time when the command for displacement in the pushing direction is started in a state where the movable portion is at the end of the actuator in the retraction direction, the movable portion is moved to the end of the actuator in the pushing direction. And measuring the extrusion time that is the time until the arrival time, the determination unit uses the feature amount related to the extrusion time, at least, from between the cylinder and the rod connected to the movable unit and the cylinder The presence or absence of an abnormality in the rod packing for preventing the leakage of the pressure fluid may be determined.

According to the configuration, the abnormality detection device determines at least the presence or absence of an abnormality in the rod packing by using the feature amount related to the extrusion time. Here, if an abnormality such as breakage occurs in the rod packing, the pressurized fluid leaks from between the rod and the cylinder, so that the extrusion time tends to be shorter (smaller). Therefore, the abnormality detecting device has an effect that it is possible to determine at least the presence or absence of the abnormality of the rod packing using the feature amount related to the extrusion time.

In the abnormality detection device according to one aspect of the present invention, the movable portion is displaced in the cylinder in a pushing direction, or in a retraction direction that is a direction opposite to the pushing direction, and the timing section is configured as the displacement time. From the time when a command for displacement in the retraction direction is started in a state where the movable portion is at the end of the actuator in the pushing direction, the movable portion is moved to the end of the actuator in the retraction direction. Measuring the withdrawal time, which is the time up to the time when it arrives at, and using the characteristic amount related to the withdrawal time, at least the pressure fluid from between the movable part and the cylinder. It may be determined whether or not there is an abnormality in the piston packing for preventing leakage of oil.

According to the configuration, the abnormality detection device determines at least presence or absence of an abnormality in the piston packing by using the characteristic amount related to the retraction time. Here, if an abnormality such as breakage occurs in the piston packing, the pressure fluid leaks from between the movable portion and the cylinder, and the retraction time tends to be long (increased). Therefore, the abnormality detection device has an effect that it is possible to determine at least the presence or absence of abnormality in the piston packing by using the characteristic amount related to the retraction time.

The abnormality detection device according to one aspect of the present invention may further include a notification control unit that notifies a user of the displacement time measured by the clock unit at a point in time when a predetermined time has elapsed from the time of activation of the actuator.

According to the configuration, the abnormality detection device has an effect that the displacement time (that is, the initial value) measured when a predetermined time has elapsed from the activation time of the actuator can be notified to a user. .

The control method according to an aspect of the present invention is a control method of an abnormality detection device that detects an abnormality of an actuator in which a movable portion is displaced by supply of a pressure fluid using a displacement time of the movable portion, wherein the displacement time As a timing step for measuring the time from the time when the command for displacement to the other end is started in a state where the movable part is at one end of the actuator, to the time when the movable part arrives at the other end, A value obtained by subtracting the minimum value of the displacement time measured so far in the time counting step from the maximum value of the displacement time measured so far in the time counting step is a predetermined time from the activation time of the actuator. A determination step of determining the presence or absence of an abnormality by using a feature amount that is a value divided by the displacement time measured in the timing step when the time has elapsed. .

According to the above-described method, the control method divides a value obtained by subtracting a minimum value from a maximum value of the displacement time measured up to the present time by the displacement time measured when a predetermined time has elapsed from the start time. The presence / absence of an abnormality in the actuator is determined using a feature value that is a value.

Generally, for an actuator in which the movable part is displaced by the supply of a pressure fluid, the displacement time of the movable part is affected by the temperature around the actuator. For example, when the temperature around the actuator increases, the displacement time tends to decrease, and when the temperature around the actuator decreases, the displacement time tends to increase. The displacement time also varies depending on the type of the actuator, the load condition, the installation position, the usage time so far, and the like.

Therefore, a conventional method of setting a normal value for the displacement time in advance and comparing the measured displacement time with a normal value to determine an abnormality has the following problems. In other words, in order to maintain the accuracy of the abnormality determination, the conventional method is individually performed according to various factors such as the temperature around the actuator, the type of the actuator, the load condition, the installation position, and the usage time so far. , It is necessary to set the normal value. In other words, the conventional method corresponds to the “conditions such as the ambient temperature and the type of the actuator” in accordance with the displacement time that varies according to “the conditions such as the ambient temperature and the type of the actuator”. Unless an appropriate normal value is appropriately set, the accuracy of the abnormality determination cannot be maintained.

On the other hand, the control method determines whether or not the actuator is abnormal by measuring a value obtained by subtracting a minimum value from a maximum value of the displacement time measured up to the present time when a predetermined time has elapsed from the start time. Is determined by using the characteristic amount which is a value obtained by dividing the calculated displacement time.

Therefore, the displacement time measured at the time of occurrence of the abnormality is the time of the displacement time measured immediately before (that is, the occurrence of the abnormality, which is at most affected only by the change in ambient temperature). It becomes larger than the maximum value or becomes smaller than the minimum value of the displacement time measured immediately before. That is, when an abnormality occurs, the displacement time measured at the current time point (= the abnormality occurrence time point) becomes the maximum value or the minimum value, and the feature amount calculated using the difference between the maximum value and the minimum value. The occurrence of an abnormality affects the Therefore, the control method can determine whether an abnormality has occurred based on the characteristic amount calculated using the difference between the maximum value and the minimum value.

In addition, the current displacement time affected by the ambient temperature change is greater than the maximum value, or less than the minimum value, the feature amount using the difference between the maximum value and the minimum value is Fluctuates according to the current displacement time affected by the temperature change. However, the magnitude of the variation of the feature quantity due to the influence of the ambient temperature change is sufficiently smaller than the magnitude of the variation of the feature quantity due to the influence of the abnormality. This is because the magnitude of the change in the displacement time due to a change in the ambient temperature is sufficiently smaller than the magnitude of the change in the displacement time due to the occurrence of an abnormality such as a failure.

In other words, the control method uses the characteristic amount using the difference between the maximum value and the minimum value to change “the change in the displacement time due to an abnormality” to “the displacement time due to a change in ambient temperature”. The effect is that it can be grasped separately from "fluctuations of".

The control method is a non-dimensional value obtained by dividing the “difference between the maximum value and the minimum value” by the “displacement time measured at the time when a predetermined time has elapsed from the start time (that is, the initial value)”. Is the feature quantity used for the abnormality determination of the actuator. That is, in the control method, a value that is not affected by the type of the actuator or the like is used as the feature amount used for determining abnormality of the actuator.

The control method, by dividing the "difference between the maximum value and the minimum value" by the "initial value" to make the dimensionless, to "difference between the maximum value and the minimum value", The influence from the type of the actuator or the like is nullified.

Therefore, the control method uses the feature amount that is made dimensionless by dividing the “difference between the maximum value and the minimum value” by the “initial value”, thereby providing various types with the same index. This has the effect that abnormality of the actuator can be determined.

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.

10 Abnormality detection device 40 Actuator 41 Cylinder 42 First end (one end, other end, end on retraction direction side)
43 2nd end (one end, the other end, end on the extrusion direction side)
46 piston (movable part)
47 Piston rod (rod)
48 Piston packing 49 Rod packing 130 Clock section 131 1st clock section (clock section)
132 Second timekeeping unit (timekeeping unit)
150 determination unit 151 first determination unit (determination unit)
152 second judgment unit (judgment unit)
160 Notification control unit T ₁ Extrusion time (displacement time)
T ₁₀ Initial value (displacement time after the lapse of a predetermined from the activation time period)
T ₂₀ Initial value (displacement time after the lapse of a predetermined from the activation time period)
T _1MAX maximum value T _2MAX maximum T _1min minimum T _2min minimum T ₂ pull-back time (displacement time)
W ₁ feature amount W ₂ feature amount S130 Timing step S160 Judgment step

Claims

An abnormality detection device that detects an abnormality of an actuator in which a movable portion is displaced by supply of a pressure fluid, using a displacement time of the movable portion,
As the displacement time, a time measuring a time from a time when a command for displacement to the other end is started in a state where the movable portion is at one end of the actuator to a time when the movable portion arrives at the other end. Department and
A value obtained by subtracting the minimum value of the displacement time measured so far by the time counting unit from the maximum value of the displacement time measured so far by the time counting unit has passed a predetermined time from the activation time of the actuator. Using a feature amount that is a value divided by the displacement time measured by the timing unit at a time, a determination unit that determines whether there is an abnormality,
An abnormality detection device comprising:
The movable section is displaced in the cylinder in a pushing direction or a retraction direction which is a direction opposite to the pushing direction,
The timing section is configured such that, as the displacement time, from the time at which a command for displacement in the pushing direction is started in a state where the movable section is at the end of the actuator on the retraction direction side, the movable section is controlled by the actuator. The extrusion time, which is the time until the end of the extrusion direction, is measured,
The determination unit uses the characteristic amount related to the extrusion time, at least, a rod packing for preventing the pressure fluid from leaking from between the rod and the cylinder connected to the movable unit. The abnormality detection device according to claim 1, wherein the presence or absence of an abnormality is determined.
The movable section is displaced in the cylinder in a pushing direction or a retraction direction which is a direction opposite to the pushing direction,
The time counting section is configured such that, as the displacement time, from the time when a command for displacement in the retraction direction is started in a state where the movable section is at the end of the actuator on the pushing direction side, the movable section is controlled by the actuator. Measure the withdrawal time, which is the time until the arrival at the end of the withdrawal direction,
The determination unit uses the characteristic amount related to the retraction time to determine at least whether there is an abnormality in the piston packing for preventing the pressure fluid from leaking from between the movable unit and the cylinder. The abnormality detection device according to claim 1, wherein the determination is performed.
The abnormality detection device according to any one of claims 1 to 3, further comprising a notification control unit configured to notify a user of the displacement time measured by the time measurement unit when a predetermined time has elapsed from the activation time of the actuator. .
A method of controlling an abnormality detection device that detects an abnormality of an actuator in which a movable portion is displaced by supply of a pressure fluid, using a displacement time of the movable portion,
As the displacement time, a time measuring a time from a time when a command for displacement to the other end is started in a state where the movable portion is at one end of the actuator to a time when the movable portion arrives at the other end. Steps and
A value obtained by subtracting the minimum value of the displacement time measured so far in the time counting step from the maximum value of the displacement time measured so far in the time counting step is a predetermined time from the activation time of the actuator. A determination step of determining the presence or absence of an abnormality using a feature amount that is a value obtained by dividing the displacement time measured in the timing step at the time when the time has elapsed,
Control method including:
An information processing program for causing a computer to function as the abnormality detection device according to any one of claims 1 to 4, wherein the information processing program causes the computer to function as each of the units.
A computer-readable recording medium on which the information processing program according to claim 6 is recorded.