PLC device

Abstract

The present disclosure accurately detects abnormalities occurring in control equipment.　This PLC device, which controls controlled equipment, is provided with: an information acquisition unit that acquires equipment monitoring information including at least a monitoring image or sound related to the controlled equipment; a signal state conversion unit that, on the basis of the equipment monitoring information acquired by the information acquisition unit, converts the state of the controlled equipment into an input / output signal state related to the controlled equipment, on the basis of a state table in which each set of determination information including at least one or more monitoring images or sounds when the controlled equipment is in a normal state is associated with the input / output signal state; an abnormality determination unit that compares the input / output signal state resulting from the conversion by the signal state conversion unit with the input / output signal state at the time when the equipment monitoring information was acquired by the information acquisition unit, and determines whether or not the controlled equipment is abnormal on the basis of the comparison result; and an abnormality notification unit that provides notification of the result of the determination by the abnormality determination unit.

Description

PLC device

[0001] The present disclosure relates to a PLC device that detects abnormalities in equipment that it controls.

[0002] Abnormalities may occur in control devices controlled by a programmable logic controller (PLC). Therefore, maintenance personnel periodically inspect the control devices controlled by the PLC to determine whether any abnormalities have occurred. Also, a technology known as a dual check safety function is known, which duplicates the signals of the control devices controlled by the PLC to detect abnormalities. For example, see Patent Document 1.

[0003] Japanese Patent Application Laid-Open No. 2023-161769

[0004] The technology described in Patent Document 1 can detect abnormalities in the PLC's CPU and broken wires connecting the PLC to the control device, but may not be able to detect abnormalities that affect both duplicated signals in the control device.

[0005] Therefore, it is desirable to detect abnormalities occurring in control devices with high accuracy.

[0006] One aspect of the PLC device disclosed herein is a PLC device that controls a controlled device, and includes: an information acquisition unit that acquires device monitoring information including at least a monitoring image or sound related to the controlled device; a signal state conversion unit that converts the state of the controlled device based on the device monitoring information acquired by the information acquisition unit into a state of the input / output signals based on a state table in which the state of the input / output signals related to the controlled device is linked to each piece of judgment information including at least one or more monitoring images or sounds related to when the controlled device is in a normal state; an abnormality judgment unit that compares the state of the input / output signals converted by the signal state conversion unit with the state of the input / output signals at the time the device monitoring information was acquired by the information acquisition unit, and determines whether the controlled device is abnormal based on the comparison result; and an abnormality notification unit that notifies the judgment result of the abnormality judgment unit.

[0007] One aspect of the PLC device disclosed herein is a PLC device that controls a controlled device, and includes: a signal state acquisition unit that acquires the state of an input / output signal related to the controlled device; a judgment information extraction unit that references a state table in which judgment information including at least a monitoring image or sound is linked to each state of one or more input / output signals related to the controlled device when the controlled device is in a normal state, and extracts the judgment information linked to the state of the input / output signal acquired by the signal state acquisition unit; an information acquisition unit that acquires equipment monitoring information including at least a monitoring image or sound related to the controlled device at the time the state of the input / output signal is acquired by the signal state acquisition unit; an abnormality judgment unit that compares the equipment monitoring information acquired by the information acquisition unit with the judgment information extracted by the judgment information extraction unit and judges whether the controlled device is abnormal based on the comparison result; and an abnormality notification unit that notifies the judgment result of the abnormality judgment unit.

[0008] 1 is a diagram showing an example of a functional block configuration of the anomaly monitoring system according to the first embodiment; FIG. 2 is a diagram showing an example of a status table; FIG. 3 is a diagram showing an example of a monitoring image stored in a storage area of ​​the status table and a monitoring image acquired by an information acquisition unit; FIG. 4 is a flowchart explaining an abnormality monitoring process of the anomaly monitoring system; FIG. 5 is a diagram showing an example of a functional block configuration of the anomaly monitoring system according to a first modified example of the first embodiment; FIG. 6 is a diagram showing an example of a status table when the determination information is the volume of a sound; FIG. 7 is a diagram showing an example of a status table when the determination information is the pitch of a sound; FIG. 8 is a diagram showing an example of a functional block configuration of the anomaly monitoring system according to a second modified example of the first embodiment; FIG. 9 is a diagram showing an example of a status table when the determination information is the frequency component of a sound;

[0009] First Embodiment An anomaly monitoring system according to a first embodiment will be described in detail below with reference to the drawings. Here, the description will be given using, as examples, an operation panel for operating a machine tool as a machine to be controlled, a safety fence, and LEDs that light up to indicate the operating status of the machine tool. The present invention is also applicable to other machines to be controlled, such as an air blower or a pump that circulates oil or coolant, in addition to the operation panel, safety fence, and LEDs. FIG. 1 is a diagram showing an example of the functional block configuration of the anomaly monitoring system according to the first embodiment. As shown in FIG. 1, the anomaly monitoring system 1 includes a PLC 10, a machine tool 20, a safety fence 30, a monitoring camera 40, and an LED 50. The safety fence 30 also includes an opening / closing sensor 35 that detects whether the safety fence 30 is open or closed. The PLC 10, the machine tool 20, the opening / closing sensor 35 of the safety fence 30, and the LED 50 may be interconnected and communicate with each other via a network (not shown), such as a local area network (LAN) or the Internet. In this case, the PLC 10, the machine tool 20, the open / close sensor 35, and the LED 50 are provided with a communication unit (not shown) for communicating with each other through such connection. Note that the PLC 10, the machine tool 20, the open / close sensor 35, and the LED 50 may be directly connected to each other via a connection interface (not shown).

[0010] <Machine Tool 20> The machine tool 20 is, for example, a machine tool known to those skilled in the art. The machine tool 20 receives commands generated based on a machining program created by a CAD / CAM device (not shown) or an operation panel 25 included in the machine tool 20 from a numerical control device (not shown) and operates in response to the commands.

[0011] <Safety Fence 30> The safety fence 30 is intended to restrict approach to the machine tool 20. An operator enters and exits the machine tool 20 through a door 31 to operate the operation panel 25 thereof, for example. The safety fence 30 is provided with an opening / closing sensor 35 to detect the entrance and exit of the operator, etc. The opening / closing sensor 35 outputs a signal corresponding to the opening and closing of the door 31 to the PLC 10, which will be described later.

[0012] <Monitoring camera 40> The monitoring camera 40 is, for example, a digital camera known to those skilled in the art. The monitoring camera 40 captures images of the opening and closing of the door 31 of the safety fence 30, the lighting of the LED 50 (described later), etc., and generates a monitoring image. The monitoring camera 40 outputs the generated monitoring image to the PLC 10 (described later).

[0013] <LED 50> The LED 50 is, for example, a light-emitting diode known to those skilled in the art, and lights up in accordance with the operating state or abnormality of the machine tool 20. This allows the operator to know the operating state or abnormality, etc. of the machine tool 20.

[0014] 1 , the PLC 10 according to this embodiment includes an information acquisition unit 110, a signal state conversion unit 120, an abnormality determination unit 130, an abnormality notification unit 140, and a storage unit 150. The PLC 10 includes a processing unit (not shown) such as a central processing unit (CPU) to realize the operations of the functional blocks in FIG. 1 . The PLC 10 also includes a main storage unit (not shown) such as an auxiliary storage unit (not shown) such as a read-only memory (ROM) or hard disk drive (HDD) that stores various control programs, and a random access memory (RAM) that stores data temporarily required for the processing unit to execute programs.

[0015] In the PLC 10, the arithmetic processing unit loads application software such as an OS and an abnormality monitoring program from the auxiliary storage device, and executes arithmetic processing based on the OS and application software while loading the loaded OS and application software into the main storage device. Based on the results of this calculation, the PLC 10 controls each piece of hardware. In this way, the processing by the functional blocks in Figure 1 is realized. In other words, the PLC 10 can be realized by the cooperation of hardware and software.

[0016] The storage unit 150 is, for example, a ROM, a solid-state drive (SSD), or a hard disk drive (HDD), and stores an operating system, application programs, and the like executed by the arithmetic processing unit. The storage unit 150 also stores a status table 151 in which the status of input / output signals to the PLC 10 is associated with each piece of determination information, including at least one monitored image (or sound) related to the safety fence 30 and the LED 50 in a normal state. The storage unit 150 may also store monitoring images captured by the monitoring camera 40 and the status of input / output signals input to and output from the PLC 10. FIG. 2 is a diagram showing an example of the status table 151. As shown in FIG. 2 , the status table 151 includes a storage area for "input / output signal status" indicating the status of the input / output signal input to the PLC 10 from the open / close sensor 35 in a normal state, and a storage area for "determination information" in which a monitoring image captured by the monitoring camera 40 indicating the status of the safety fence 30 corresponding to the status of the input / output signal is stored. The storage area for "determination information" in the state table 151 stores, for example, a monitoring image captured by the monitoring camera 40, showing the state of the door 31 of the safety fence 30. For example, as shown in FIG. 2 , the storage area for "determination information" stores a monitoring image in which the door 31 is open or closed. The storage area for "input / output signal status" in the state table 151 stores, for example, the status of the input / output signal input from the open / close sensor 35 to the PLC 10 for each piece of "determination information." For example, as shown in FIG. 2 , the storage area for "input / output signal status" stores the status of the input / output signal "X10.0" input from the open / close sensor 35 to the PLC 10, that is, the input / output signal state in which the input / output signal "X10.0" is "on" (i.e., the door 31 is open) for the monitoring image in which the door 31 is open. In addition, the storage area for "input / output signal status" stores the status of the input / output signal "X10.0" input from the opening / closing sensor 35 to the PLC 10 when the monitoring image shows the door 31 closed (i.e., the door 31 is closed) in the storage area for "determination information."

[0017] The information acquisition unit 110 acquires device monitoring information including at least a monitoring image or sound related to the device to be controlled. Specifically, the information acquisition unit 110 acquires, for example, a monitoring image captured by the monitoring camera 40 from the monitoring camera 40 as the device monitoring information.

[0018] The signal state conversion unit 120 converts the state of the safety fence 30, LED 50, etc., to be controlled based on the equipment monitoring information acquired by the information acquisition unit 110, into the state of input / output signals related to the safety fence 30, LED 50, etc. Specifically, the signal state conversion unit 120 refers to the state table 151, for example, and calculates the similarity between the monitoring image included in the equipment monitoring information acquired by the information acquisition unit 110 and the monitoring image in the storage area for "determination information" in the state table 151. For example, the signal state conversion unit 120 calculates the similarity R between each monitoring image stored in the storage area for "determination information" in the state table 151 and the monitoring image acquired by the information acquisition unit 110 using Equation 1, which is the Sum of Squared Difference (SSD) of a known image analysis method (for example, template matching, etc.). ＳＳＤ Calculate. Here, I(x+i, y+j) indicates the pixel value of the monitoring image acquired by the information acquisition unit 110. T(i, j) indicates the pixel value of each monitoring image stored in the storage area of ​​the "determination information" in the state table 151. In addition, the similarity R calculated using Equation 1 ＳＳＤ The value of is smaller as the monitoring image in the equipment monitoring information and the monitoring image in the storage area of ​​"determination information" in the status table 151 become more similar. For example, as shown in FIG. 3, if the monitoring image in the equipment monitoring information acquired by the information acquisition unit 110 and the monitoring image stored in the top storage area of ​​"determination information" in the status table 151 are images each having nine pixels, the signal status conversion unit 120 calculates the similarity R using Equation 1. ＳＳＤ R ＳＳＤ = (183 - 183) ２ + (174-175) ２ + (172-173) ２ + (153-153) ２ + (142-142) ２ + (147-148) ２+ (168-167) ２ + (115-114) ２ +(110-108) ２ As described above, when two images are similar to each other, the similarity R ＳＳＤ Since R is a small value, if the threshold value is set to a predetermined value (for example, "500") in advance, the signal state conversion unit 120 ＳＳＤ = 9 < 500, the determination information including the top monitoring image is extracted from the storage area of ​​"determination information" in the status table 151. The signal status conversion unit 120 converts the device monitoring information acquired by the information acquisition unit 110 into the input / output signal status "X10.0: ON" in the storage area of ​​"input / output signal status" linked to the extracted determination information. Note that the signal status conversion unit 120 converts the device monitoring information acquired by the information acquisition unit 110 into the input / output signal status "X10.0: ON" in the storage area of ​​"input / output signal status" linked to the extracted determination information. ＳＳＤ is equal to or greater than the threshold value (i.e., when it is determined that there is no similarity), the similarity R between the monitoring image stored in the next second storage area among the storage areas for "determination information" in the status table 151 and the monitoring image of the equipment monitoring information acquired by the information acquisition unit 110 is ＳＳＤ Calculate.

[0019] The abnormality determination unit 130 compares the state of the input / output signal converted by the signal state conversion unit 120 with the state of the input / output signal at the time when the equipment monitoring information was acquired by the information acquisition unit 110, and determines whether or not the operation of the open / close sensor 35, LED 50, etc. of the safety fence 30 to be controlled is abnormal based on the comparison result. Specifically, the abnormality determination unit 130 compares, for example, the state of the input / output signal "X10.0: ON" in the monitoring image of Fig. 3 converted by the signal state conversion unit 120 based on the state table 151 with the state of the input / output signal "X10.0" input to the PLC 10 from the open / close sensor 35 at the time when the monitoring image was captured by the monitoring camera 40. If the state of the input / output signal input from the open / close sensor 35 to the PLC 10 at the time the monitoring image was captured by the monitoring camera 40 was "X10.0: On," the abnormality determination unit 130 determines that the operation of the safety fence 30 is normal because this matches the state of the input / output signal "X10.0: On" in the monitoring image of Fig. 3 converted by the signal state conversion unit 120. On the other hand, if the state of the input / output signal "X10.0" output from the open / close sensor 35 and input to the PLC 10 at the time the monitoring image was captured by the monitoring camera 40 was "Off," the abnormality determination unit 130 determines that the operation of the safety fence 30 is abnormal because this does not match the state of the input / output signal "X10.0: On" in the monitoring image of Fig. 3 converted by the signal state conversion unit 120. In this way, the PLC 10 can accurately detect abnormalities occurring in control devices such as the safety fence 30.

[0020] The abnormality notification unit 140 notifies the judgment result of the abnormality judgment unit 130 to an operator's smartphone, tablet terminal, personal computer, etc. (not shown), and displays it on the display of the smartphone, tablet terminal, personal computer, etc. (not shown).

[0021] <Abnormality Monitoring Process of Anomaly Monitoring System 1> Next, the flow of abnormality monitoring process of the abnormality monitoring system 1 will be described with reference to Fig. 4. Fig. 4 is a flowchart illustrating the abnormality monitoring process of the abnormality monitoring system 1.

[0022] In step S11, the information acquisition unit 110 acquires, for example, a monitoring image captured by the monitoring camera 40 from the monitoring camera 40 as device monitoring information.

[0023] In step S12, the signal state conversion unit 120 refers to the state table 151 and calculates the similarity R between one monitoring image stored in the storage area of ​​the "determination information" in the state table 151 and the monitoring image included in the equipment monitoring information acquired in step S11. ＳＳＤ is calculated using equation 1.

[0024] In step S13, the signal state conversion unit 120 converts the similarity R calculated in step S12 into ＳＳＤ It is determined whether the similarity R is smaller than a threshold value. ＳＳＤ If the similarity R is smaller than the threshold value (i.e., if the similarity is determined to be high), the process proceeds to step S14. ＳＳＤ is equal to or greater than the threshold value (i.e., it is determined that the image is not similar), the similarity R ＳＳＤ The process returns to step S12 to calculate

[0025] In step S14, the signal state conversion unit 120 converts the signal state in the state table 151 into a signal state having a similarity R smaller than the threshold value. ＳＳＤ The judgment information in the storage area for the calculated "judgment information" is extracted, and the equipment monitoring information acquired in step S11 is converted into the state of the input / output signal in the storage area for the "state of the input / output signal" linked to the extracted judgment information.

[0026] In step S15, the abnormality judgment unit 130 compares the state of the input / output signal converted in step S14 with the state of the input / output signal at the time the equipment monitoring information was acquired in step S11, and judges whether or not the equipment is abnormal based on the comparison result.

[0027] In step S16, the abnormality notification unit 140 notifies and displays the determination result of step S15 on the operator's smartphone, tablet terminal, personal computer, or the like (not shown).

[0028] As described above, the PLC 10 according to the first embodiment can detect with high accuracy an abnormality that has occurred in a control device based on device monitoring information including a monitoring image captured by the monitoring camera 40. The first embodiment has been described above.

[0029] <First Modification of First Embodiment> In the first embodiment, the equipment monitoring information includes monitoring images captured by the monitoring camera 40. However, this is not limiting. For example, the equipment monitoring information may include sound information (e.g., sound volume) collected using a microphone. FIG. 5 is a diagram illustrating an example of a functional block configuration of an abnormality monitoring system 1 according to a first modification of the first embodiment. Elements having similar functions to those of the abnormality monitoring system 1 in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. As illustrated in FIG. 5 , the abnormality monitoring system 1 includes a PLC 10, a blower 60, a control panel 70 for the blower 60, and a microphone 80. While FIG. 5 illustrates an example in which the blower 60 is disposed as a sound source, a machine tool (not shown) may also be disposed because the machine tool generates sound during machining or other operations. The PLC 10, the blower 60, the control panel 70, and the microphone 80 may be interconnected and communicate with each other via a network (not shown), such as a LAN or the Internet. In this case, the PLC 10, the blower 60, the operation panel 70, and the microphone 80 are provided with a communication unit (not shown) for communicating with each other through such connection. Note that the PLC 10, the blower 60, the operation panel 70, and the microphone 80 may be directly connected to each other via a connection interface (not shown).

[0030] FIG. 6 is a diagram showing an example of the state table 151-1 when the determination information is the volume of sound. As shown in FIG. 6, the state table 151-1 has a storage area for "input / output signal state" indicating the state of the input / output signal input to the PLC 10 from the operation panel 70 of the blower 60, and "determination information" indicating the state of the blower 60 corresponding to the state of the input / output signal by the volume of sound collected by the microphone 80. The storage area for "determination information" in the state table 151-1 stores, for example, the volume of sound collected by the microphone 80 from the blower 60, etc. The storage area for "input / output signal state" in the state table 151-1 stores, for example, the state of the input / output signal input to the PLC 10 from the operation panel 70 of the blower 60 for each piece of "determination information." 6, the storage area for "input / output signal status" stores the status of the input / output signal "Y0.0: off" input from the operation panel 70 to the PLC 10 when the sound volume is "40 dB" when the blower 60 is stopped in the storage area for "determination information." Also, the storage area for "input / output signal status" stores the status of the input / output signals "X0.0: on," "X0.1: on," and "Y0.0: on" input from the operation panel 70 to the PLC 10 when the sound volume is "50 dB" when the blower 60 is operating in the storage area for "determination information."

[0031] 1, the signal state conversion unit 120 refers to the state table 151-1 and calculates the similarity between the loudness of the sound included in the device monitoring information acquired by the information acquisition unit 110 and the loudness of the sound stored in the storage area for "determination information" in the state table 151-1. For example, if the loudness of the fan 60 acquired by the information acquisition unit 110 is "51 dB," the signal state conversion unit 120 calculates the similarity between this loudness and the loudness of the "determination information" of "40 dB" when the "state of input / output signal" in the state table 151-1 is "Y0.0: Off" as the absolute value of the difference |51-40|=11. Furthermore, the signal state conversion unit 120 calculates the similarity between the "state of input / output signals" in the state table 151-1, which is "X0.0: on," "X0.1: on," and "Y0.0: on," and the loudness "50 dB" of the "determination information," as the absolute value of the difference |51-50| = 1. For example, when a threshold value is set to a predetermined value (e.g., "5"), the similarity "1" between the loudness "50 dB" of the storage area of ​​the "determination information" is smaller than the threshold value, and therefore the signal state conversion unit 120 converts "X0.0: on," "X0.1: on," and "Y0.0: on" as the states of the input / output signals input to the PLC 10.

[0032] The equipment monitoring information may also include the peak frequency (pitch) of the sound as sound information. In this case, the signal state conversion unit 120 may calculate the similarity between the sound pitch in the acquired equipment monitoring information and the sound pitch stored in the storage area for "determination information" in the state table based on the sound pitch, and convert the calculated value into the state of the input / output signal related to the fan 60. FIG. 7 is a diagram showing an example of a state table 151-2 in which the determination information is sound pitch. As shown in FIG. 7, the storage area for "determination information" in the state table 151-2 stores, for example, the pitch (peak frequency) of the sound of the fan 60, etc., collected by the microphone 80. As in the case of FIG. 6, the storage area for "input / output signal state" in the state table 151-2 stores the state of the input / output signal input from the operation panel 70 of the fan 60 to the PLC 10 for each "determination information." The signal state conversion unit 120 refers to the state table 151-2 in Fig. 7 and calculates the similarity between the pitch of the sound included in the device monitoring information acquired by the information acquisition unit 110 and the pitch of the sound stored in the storage area for "determination information" in the state table 151-2 in Fig. 7. For example, if the pitch (peak frequency) of the sound of the fan 60 acquired by the information acquisition unit 110 is "3 Hz," the signal state conversion unit 120 calculates the similarity with the pitch of "0 Hz" of the "determination information" when the "state of input / output signal" in the state table 151-2 is "Y0.0: Off" as the absolute value of the difference |3 - 0| = 3. Furthermore, the signal state conversion unit 120 calculates the similarity between the "state of input / output signals" in the state table 151-2, which is "X0.0: on," "X0.1: on," and "Y0.0: on," and the pitch "300 Hz" of the "determination information," as the absolute value of the difference |3-300| = 297. For example, when a threshold value is set to a predetermined value (e.g., "10"), the signal state conversion unit 120 converts the state of the input / output signals input to the PLC 10 to "Y0.0: off," because the similarity "3" with the pitch "0 Hz" in the storage area of ​​the "determination information" is smaller than the threshold value.

[0033] <Modification 2 of First Embodiment> In the first embodiment, the equipment monitoring information includes monitoring images captured by the monitoring camera 40. However, this is not limiting. For example, if the anomaly monitoring system 1 has two or more fans, each of the fans emits sound at a unique frequency. The unique frequency components of each fan can be extracted by Fourier transforming the sound collected by the microphone. Therefore, the equipment monitoring information may include the sound frequency components as sound information. FIG. 8 is a diagram showing an example of a functional block configuration of the anomaly monitoring system 1 according to Modification 2 of the first embodiment. Note that elements having the same functions as those of the anomaly monitoring system 1 of FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. As shown in FIG. 8, the anomaly monitoring system 1 includes a PLC 10, fans 60(1) and 60(2), operation panels 70a for the fans 60(1) and 60(2), and a microphone 80. The PLC 10, the fans 60(1) and 60(2), the operation panel 70a, and the microphone 80 may be connected to each other via a network (not shown) such as a LAN or the Internet to communicate with each other. In this case, the PLC 10, the fans 60(1) and 60(2), the operation panel 70a, and the microphone 80 are provided with a communication unit (not shown) for communicating with each other via such a connection. Note that the PLC 10, the fans 60(1) and 60(2), the operation panel 70a, and the microphone 80 may also be directly connected to each other via a connection interface (not shown).

[0034] FIG. 9 is a diagram illustrating an example of sounds emitted by two fans 60(1) and 60(2). The first row of FIG. 9 shows an example of the change over time of a sound with a frequency of 295 Hz emitted by fan 60(1). The second row shows an example of the change over time of a sound with a frequency of 605 Hz emitted by fan 60(2). The third row shows an example of the change over time of a sound obtained by superimposing the sounds of fans 60(1) and 60(2) collected by microphone 80. The fourth row shows an example of a spectrum obtained by Fourier transforming the sound collected by microphone 80 in the third row, showing that the natural frequencies of fans 60(1) and 605 Hz, respectively, are separated.

[0035] FIG. 10 is a diagram showing an example of a state table 151-3 in which the determination information is the frequency component of sound. As shown in FIG. 10 , the state table 151-3 has a storage area for "input / output signal status" indicating the status of input / output signals input to the PLC 10 from the operation panels 70a of the fans 60(1) and 60(2), and "determination information" indicating the frequency component of the sound emitted by the fans 60(1) and 60(2) and collected by the microphone 80, corresponding to the state of the input / output signal. The storage area for "determination information" in the state table 151-3 stores, for example, the frequency component of the sound of the fans 60(1) and 60(2) collected by the microphone 80. The storage area for "input / output signal status" in the state table 151-3 stores, for example, the status of the input / output signals input to the PLC 10 from the operation panels 70a of the fans 60(1) and 60(2) for each "determination information." 10 , in the storage area for the “state of input / output signals,” the states of the input / output signals input from the operation panel 70a to the PLC 10 in the case of a sound frequency component of “0 Hz” (i.e., when the fans 60(1) and 60(2) are stopped) are stored in the storage area for the “determination information.” In addition, in the storage area for the “state of input / output signals,” the states of the input / output signals input from the operation panel 70a to the PLC 10 in the case of a sound frequency component of “300 Hz” when only the fan 60(1) is operating are stored in the storage area for the “determination information.” In addition, the storage area for "status of input / output signals" stores the input / output signals "X0.1: off," "Y0.0: off," "X10.1: on," and "Y10.0: on" input from the control panel 70a to the PLC 10 when the sound frequency component is "600 Hz" when only the fan 60(2) is operating, as stored in the storage area for "determination information."In addition, the storage area for the "status of input / output signals" stores the input / output signals "X0.1: on," "Y0.0: on," "X10.1: on," and "Y10.0: on" that are output from the operation panel 70a and input to the PLC 10 when the frequency components of the sound are "300 Hz" and "600 Hz" when the blowers 60(1) and 60(2) are operating, respectively, in the storage area for the "determination information."

[0036] The signal state conversion unit 120, for example, similar to the signal state conversion unit 120 in Figure 1, refers to the state table 151-3 and calculates the similarity between the frequency components of the sound contained in the equipment monitoring information acquired by the information acquisition unit 110 and the frequency components of the sound for each storage area of ​​the "determination information" in the state table 151-3. Specifically, for example, the signal state conversion unit 120 uses the frequency component “295 Hz” of the sound of fan 60(1) and the frequency component “605 Hz” of the sound of fan 60(2) in the equipment monitoring information acquired by the information acquisition unit 110 when fans 60(1) and 60(2) are operating, and the frequency component “0 Hz” of the sound in the storage area for “determination information” in the state table 151-3, to calculate the similarity of the frequency components between the equipment monitoring information and the determination information for fans 60(1) and 60(2) as the absolute value of the difference between |295-0|=295 and |605-0|=605. Furthermore, when fans 60(1) and 60(2) are operating, the signal state conversion unit 120 uses the frequency component "300 Hz" of the sound in the storage area for "determination information" to calculate the similarity between the frequency components of the equipment monitoring information and the determination information for fans 60(1) and 60(2) as the absolute value of the difference between |295-300| = 5 and |605-300| = 305. Furthermore, when fans 60(1) and 60(2) are operating, the signal state conversion unit 120 uses the frequency component "600 Hz" of the sound in the storage area for "determination information" to calculate the similarity between the frequency components of the equipment monitoring information and the determination information for fans 60(1) and 60(2) as the absolute value of the difference between |295-600| = 305 and |605-500| = 5.

[0037] Furthermore, when fans 60(1) and 60(2) are operating, signal state conversion unit 120 uses the sound frequency components “300 Hz” and “600 Hz” in the storage area for “determination information” to calculate the similarity between the frequency components of the equipment monitoring information and the determination information for fans 60(1) and 60(2) as the absolute value of the difference between |295-300|=5 and |605-600|=5. For example, when the threshold value is preset to a predetermined value (such as "10"), the signal state conversion unit 120 converts the state of the input / output signal input to PLC 10 to "X0.1: on", "Y0.0: on", "X10.1: on", "Y10.0: on" (i.e., fans 60(1) and 60(2) are operating) because the similarity is smaller than the threshold value when the frequency components of the sound are "300 Hz" and "600 Hz" in the "determination information" of state table 151-3.

[0038] Second Embodiment Next, a second embodiment will be described. In the first embodiment, the PLC 10 acquires device monitoring information including at least a monitor image or sound related to the device, converts the device status into the status of an input / output signal related to the device based on the acquired device monitoring information, and compares the converted input / output signal status with the status of the input / output signal at the time the device monitoring information was acquired to determine whether the device is abnormal. In contrast, in the second embodiment, the PLC 10A acquires the status of the input / output signal related to the device, references a status table in which determination information including at least a monitor image or sound is associated with each of one or more input / output signals related to the device, extracts determination information associated with the acquired input / output signal, acquires device monitoring information including at least a monitor image or sound related to the device at the time the status of the input / output signal was acquired, and compares the acquired device monitoring information with the extracted determination information to determine whether the device is abnormal. As a result, according to the second embodiment, the PLC 10A can accurately detect an abnormality occurring in a control device. The second embodiment will be described below.

[0039] FIG. 11 is a diagram showing an example of a functional block configuration of an abnormality monitoring system 1 according to the second embodiment. Elements having similar functions to those of the abnormality monitoring system 1 shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted. As shown in FIG. 11 , the abnormality monitoring system 1 includes a PLC 10A, a machine tool 20, a safety fence 30, a monitoring camera 40, and an LED 50. The safety fence 30 also includes an open / close sensor 35 that detects whether the safety fence 30 is open or closed. The PLC 10A, the machine tool 20, the open / close sensor 35, and the LED 50 may be interconnected and communicate with each other via a network (not shown), such as a LAN or the Internet. In this case, the PLC 10A, the machine tool 20, the open / close sensor 35, and the LED 50 each include a communication unit (not shown) for communicating with each other via such a connection. The PLC 10A, the machine tool 20, the open / close sensor 35, and the LED 50 may also be directly connected to each other via a connection interface (not shown). The machine tool 20, safety fence 30, open / close sensor 35, and LED 50 have the same functions as the machine tool 20, safety fence 30, open / close sensor 35, and LED 50 of the first embodiment. In the following description, the monitoring camera 40 will be described as generating a monitoring image capturing the entire anomaly monitoring system 1.

[0040] 11 , the PLC 10A includes a signal state acquisition unit 160, a determination information extraction unit 170, an information acquisition unit 110a, an abnormality determination unit 130a, an abnormality notification unit 140, and a storage unit 150a. The abnormality notification unit 140 has the same functions as the abnormality notification unit 140 of the first embodiment. The PLC 10A also includes a processing unit (not shown), such as a CPU, to realize the operation of the functional blocks in FIG. 11 . The PLC 10A also includes a main storage unit (not shown), such as a ROM, HDD, or other auxiliary storage device (not shown) that stores various control programs, and a RAM for storing data temporarily required for the processing unit to execute the programs.

[0041] In the PLC 10A, the arithmetic processing unit loads application software such as the OS and anomaly monitoring program from the auxiliary storage device, and executes arithmetic processing based on the OS and application software while loading the loaded OS and application software into the main storage device. Based on the results of this calculation, the PLC 10A controls each piece of hardware. This allows the processing by the functional blocks in Figure 11 to be realized. In other words, the PLC 10A can be realized by the cooperation of hardware and software.

[0042] The storage unit 150a is, for example, a ROM, SSD, HDD, or the like, similar to the storage unit 150 of the first embodiment, and stores an operating system, application programs, and the like executed by the arithmetic processing unit. The storage unit 150a also stores a status table 151a in which determination information including at least a monitoring image (or sound) is linked to each state of an input / output signal related to the safety fence 30 and the LED 50 in a normal state. The storage unit 150a may also store monitoring images captured by the monitoring camera 40. FIG. 12 is a diagram illustrating an example of the status table 151a. As illustrated in FIG. 12, the status table 151a includes storage areas for "input / output signal status" indicating the state of the input / output signal input from the open / close sensor 35 to the PLC 10A and the state of the input / output signal output from the PLC 10A to the LED 50 in a normal state, and "determination information" for a monitoring image captured by the monitoring camera 40 indicating the state of the safety fence 30 and the LED 50 corresponding to the state of the two input / output signals. The storage area for "input / output signal status" in the status table 151a stores the status of the input / output signal input from the open / close sensor 35 to the PLC 10A and the status of the input / output signal output from the PLC 10A to the LED 50. For example, when the door 31 of the safety fence 30 is closed, the status of the input / output signal input from the open / close sensor 35 to the PLC 10A is "X10.0: off." When the door 31 of the safety fence 30 is open, the status of the input / output signal input from the open / close sensor 35 to the PLC 10A is "X10.0: on." On the other hand, for example, when no abnormality or the like has occurred in the machine tool 20, the LED 50 does not light up, and therefore the status of the input / output signal output from the PLC 10A to the LED 50 is "Y20.0: off." When an abnormality or the like has occurred in the machine tool 20, the LED 50 lights up, and therefore the status of the input / output signal output from the PLC 10A to the LED 50 is "Y20.0: on."

[0043] The storage area for "determination information" in the state table 151a stores, for example, monitoring images captured by the monitoring camera 40 for each "state of the input / output signal" that show the state of the door 31 of the safety fence 30 and the LED 50. For example, if the state of the input / output signal input from the open / close sensor 35 to the PLC 10A is "X10.0: off" and the state of the input / output signal output from the PLC 10A to the LED 50 is "Y20.0: off," the storage area for "determination information" stores a monitoring image in which the door 31 is closed and the LED 50 is off. Also, if the state of the input / output signal input from the open / close sensor 35 to the PLC 10A is "X10.0: on" and the state of the input / output signal output from the PLC 10A to the LED 50 is "Y20.0: off," the storage area for "determination information" stores a monitoring image in which the door 31 is open and the LED 50 is off. Furthermore, if the state of the input / output signal input from the open / close sensor 35 to the PLC 10A is "X10.0: off" and the state of the input / output signal output from the PLC 10A to the LED 50 is "Y20.0: on", a monitoring image in which the door 31 is closed and the LED 50 is on is stored in the storage area for "determination information". Furthermore, if the state of the input / output signal input from the open / close sensor 35 to the PLC 10A is "X10.0: on" and the state of the input / output signal output from the PLC 10A to the LED 50 is "Y20.0: on", a monitoring image in which the door 31 is open and the LED 50 is on is stored in the storage area for "determination information".

[0044] The signal state acquisition unit 160 acquires the state of input / output signals related to the open / close sensor 35, LED 50, and the like of the safety fence 30, which is a device to be controlled. Specifically, for example, in the situation shown in Fig. 11 , the door 31 of the safety fence 30 is open, so the signal state acquisition unit 160 acquires the state "X10.0: ON" of the input / output signal input from the open / close sensor 35 to the PLC 10A. Furthermore, since the LED 50 is lit, the signal state acquisition unit 160 acquires the state "Y20.0: ON" of the input / output signal output from the PLC 10A to the LED 50.

[0045] The determination information extraction unit 170 refers to the state table 151a in which determination information including at least a monitoring image or a sound is associated with each state of one or more input / output signals related to devices such as the open / close sensor 35 and the LED 50 of the safety fence 30 when the devices are in a normal state, and extracts determination information associated with the states of the input / output signals acquired by the signal state acquisition unit 160. Specifically, in the situation shown in Fig. 11 , for example, the determination information extraction unit 170 extracts from the state table 151a determination information of a monitoring image in a normal state in which the door 31 is open and the LED 50 is on, which is associated with the state "X10.0: on" of the input / output signal input from the open / close sensor 35 to the PLC 10A acquired by the signal state acquisition unit 160 and the state "Y20.0: on" of the input / output signal output from the PLC 10A to the LED 50.

[0046] The information acquiring unit 110a acquires equipment monitoring information including at least a monitoring image or sound related to equipment such as the open / close sensor 35 and the LED 50 of the safety fence 30 at the time when the state of the input / output signal is acquired by the signal state acquiring unit 160. Specifically, in the case of the situation shown in Fig. 11 , for example, the information acquiring unit 110a acquires equipment monitoring information of a monitoring image of the anomaly monitoring system 1 including the safety fence 30 and the LED 50 captured by the monitoring camera 40 from the storage unit 150a at the time when the signal state acquiring unit 160 acquires the state "X10.0: on" of the input / output signal input from the open / close sensor 35 to the PLC 10A and the state "Y20.0: on" of the input / output signal output from the PLC 10A to the LED 50.

[0047] The abnormality determination unit 130a compares the equipment monitoring information acquired by the information acquisition unit 110a with the determination information extracted by the determination information extraction unit 170 based on the state table 151a, and determines whether or not the operation of the open / close sensor 35, LED 50, etc. of the safety fence 30 to be controlled is abnormal based on the comparison result. Specifically, the abnormality determination unit 130a calculates, for example, the similarity R between the monitoring image included in the equipment monitoring information acquired by the information acquisition unit 110a and the monitoring image extracted by the determination information extraction unit 170 from the storage area for "determination information" in the state table 151a. ＳＳＤ The abnormality determination unit 130a calculates the calculated similarity RＳＳＤ is smaller than a preset threshold value (for example, "50") (i.e., when it is determined that they are similar), the monitoring image included in the equipment monitoring information matches the monitoring image extracted from the storage area for the "determination information", and therefore it is determined that there is no abnormality in the operation of the open / close sensor 35 and the LED 50 of the safety fence 30. On the other hand, the abnormality determination unit 130a determines that the calculated similarity R ＳＳＤ is equal to or greater than a preset threshold (i.e., when it is determined that they are not similar), the monitoring image included in the equipment monitoring information does not match the monitoring image extracted from the storage area for "determination information," and therefore it is determined that there is an abnormality in the operation of the open / close sensor 35 of the safety fence 30 or the LED 50, etc. In this way, the PLC 10A can detect an abnormality that has occurred in the control equipment with a high degree of accuracy.

[0048] <Abnormality monitoring process of abnormality monitoring system 1> Next, the flow of abnormality monitoring process of the abnormality monitoring system 1 will be described with reference to Fig. 13. Fig. 13 is a flowchart illustrating the abnormality monitoring process of the abnormality monitoring system 1. Note that the process of step S28 is the same as the process of step S16 in Fig. 4, and therefore description thereof will be omitted.

[0049] In step S21, the signal state acquisition unit 160 acquires the state of input / output signals relating to devices such as the open / close sensor 35 of the safety fence 30 and the LED 50.

[0050] In step S22, the determination information extractor 170 refers to the state table 151a and extracts the determination information associated with the state of the input / output signal acquired in step S21.

[0051] In step S23, the information acquisition unit 110a acquires from the storage unit 150a equipment monitoring information of the equipment such as the open / close sensor 35 and the LED 50 of the safety fence 30 at the time of acquisition of the state of the input / output signal acquired in step S21.

[0052] In step S24, the abnormality determination unit 130a uses Equation 1 to calculate the similarity R between the monitoring image included in the equipment monitoring information acquired in step S23 and the monitoring image included in the determination information extracted in step S22. ＳＳＤ Calculate.

[0053] In step S25, the abnormality determination unit 130a calculates the similarity R ＳＳＤ It is determined whether the similarity R is smaller than a threshold value. ＳＳＤ If the similarity R is smaller than the threshold value (i.e., if the similarity is determined to be high), the process proceeds to step S26. ＳＳＤ If is equal to or greater than the threshold value (that is, if it is determined that there is no similarity), the process proceeds to step S27.

[0054] In step S26, the abnormality determining unit 130a determines that the device is normal.

[0055] In step S27, the abnormality determination unit 130a determines that the device is abnormal.

[0056] As described above, the PLC 10A according to the second embodiment can accurately detect an abnormality that has occurred in a control device based on device monitoring information including a monitoring image captured by the monitoring camera 40. The second embodiment has been described above.

[0057] <First Modification of Second Embodiment> In the second embodiment, the equipment monitoring information includes monitoring images captured by the monitoring camera 40. However, this is not limiting. For example, the equipment monitoring information may include sound information (e.g., sound volume) collected using a microphone. FIG. 14 is a diagram illustrating an example of a functional block configuration of an anomaly monitoring system 1 according to a first modification of the second embodiment. Elements having similar functions to those of the anomaly monitoring system 1 in FIG. 11 are denoted by the same reference numerals, and detailed description thereof will be omitted. As shown in FIG. 14 , the anomaly monitoring system 1 includes a PLC 10A, a blower 60, a control panel 70 for the blower 60, and a microphone 80. The blower 60, the control panel 70, and the microphone 80 have similar functions to the blower 60, the control panel 70, and the microphone 80 in FIG. 5. While FIG. 14 illustrates an example in which blowers 60(1) and 60(2) are arranged as sound sources, two machine tools (not shown) may be arranged because machine tools generate sound during operations such as machining. The PLC 10A, the blower 60, the operation panel 70, and the microphone 80 may be connected to each other and communicate via a network (not shown) such as a LAN or the Internet. In this case, the PLC 10A, the blower 60, the operation panel 70, and the microphone 80 are provided with a communication unit (not shown) for communicating with each other via such a connection. Note that the PLC 10A, the blower 60, the operation panel 70, and the microphone 80 may also be directly connected to each other via a connection interface (not shown).

[0058] The state table stored in the storage unit 150a of the PLC 10A when the determination information is the volume of the sound is the same as the state table 151-1 in FIG. 6, and therefore a description thereof will be omitted.

[0059] For example, if the signal status acquisition unit 160 acquires "Y0.0: Off" as the status of the input / output signal input to the PLC 10A from the microphone 80, the determination information extraction unit 170 refers to the status table 151-1 and extracts determination information including a sound level of "40 dB" associated with the acquired "Y0.0: Off" state of the input / output signal. The information acquisition unit 110a acquires equipment monitoring information (e.g., "50 dB") regarding the sound level of the blower 60 at the time when the signal status acquisition unit 160 acquires the "Y0.0: Off" state of the input / output signal. The abnormality determination unit 130a calculates the similarity between the sound level included in the equipment monitoring information acquired by the information acquisition unit 110a and the sound level of "40 dB" in the determination information extracted by the determination information extraction unit 170 as the absolute value of the difference |40-50|=10. If the calculated similarity is smaller than a preset threshold, the abnormality judgment unit 130a judges that the blower 60 is normal, and if the calculated similarity is equal to or greater than the preset threshold, it judges that the blower 60 is abnormal.

[0060] The device monitoring information may also include the peak frequency (pitch) of the sound as sound information. In this case, the state table in which the determination information is the pitch of the sound is similar to the state table 151-2 in FIG. 7, and therefore a description thereof will be omitted.

[0061] For example, if the signal state acquisition unit 160 acquires "X0.0: On," "X0.1: On," and "Y0.0: On" as the states of the input / output signal input to the PLC 10A from the microphone 80, the determination information extraction unit 170 refers to the state table 151-2 and extracts determination information including the pitch of "300 Hz" associated with the acquired states of the input / output signals "X0.0: On," "X0.1: On," and "Y0.0: On." The information acquisition unit 110a acquires device monitoring information (e.g., "310 Hz") of the pitch of the fan 60 at the time when the signal state acquisition unit 160 acquires the states of the input / output signals "X0.0: On," "X0.1: On," and "Y0.0: On." The abnormality determination unit 130a calculates the similarity between the pitch of the sound included in the equipment monitoring information acquired by the information acquisition unit 110a and the pitch of the sound extracted by the determination information extraction unit 170 from the storage area for "determination information" in the status table 151-2 as the absolute value of the difference |300-310|=10. If the calculated similarity is smaller than a preset threshold, the abnormality determination unit 130a determines that the fan 60 is normal, and if the calculated similarity is equal to or greater than the preset threshold, the abnormality determination unit 130a determines that the fan 60 is abnormal.

[0062] <Modification 2 of Second Embodiment> In the second embodiment, the equipment monitoring information includes monitoring images captured by the monitoring camera 40, but this is not limited thereto. For example, if the anomaly monitoring system 1 has two or more fans, each of the fans emits sound at a unique frequency. The unique frequency components of each fan can be extracted by Fourier transforming the sound collected by the microphone. Therefore, the equipment monitoring information may include the sound frequency components as sound information. FIG. 15 is a diagram showing an example of the functional block configuration of the anomaly monitoring system 1 according to Modification 2 of the second embodiment. Elements having the same functions as those of the anomaly monitoring system 1 in FIG. 11 are denoted by the same reference numerals and will not be described in detail. As shown in FIG. 15, the anomaly monitoring system 1 includes a PLC 10A, fans 60(1) and 60(2), operation panels 70a for the fans 60(1) and 60(2), and a microphone 80. The fans 60(1) and 60(2), the operation panel 70a, and the microphone 80 have functions equivalent to those of the fans 60, the operation panel 70a, and the microphone 80 in FIG. 8 . The PLC 10A, the fans 60(1) and 60(2), the operation panel 70a, and the microphone 80 may be interconnected and communicate with each other via a network (not shown) such as a LAN or the Internet. In this case, the PLC 10A, the fans 60(1) and 60(2), the operation panel 70a, and the microphone 80 include a communication unit (not shown) for communicating with each other via such a connection. The PLC 10A, the fans 60(1) and 60(2), the operation panel 70a, and the microphone 80 may also be directly connected to each other via a connection interface (not shown).

[0063] The state table stored in the storage unit 150a of the PLC 10A when the determination information is the frequency component of the sound is similar to the state table 151-3 in FIG. 10, and therefore a description thereof will be omitted.

[0064] For example, if the signal state acquisition unit 160 acquires "X0.1: On," "Y0.0: On," "X10.1: On," and "Y10.0: On" as the states of the input / output signals input to the PLC 10A from the microphone 80, the determination information extraction unit 170 references the state table 151-3 and extracts determination information including the frequency components "300 Hz, 600 Hz" of the sound associated with the acquired input / output signal states "X0.1: On," "Y0.0: On," "X10.1: On," and "Y10.0: On." The information acquisition unit 110a acquires device monitoring information including the frequency components (e.g., "295 Hz," "605 Hz," etc.) of the sound associated with the fans 60(1) and 60(2) at the time when the signal state acquisition unit 160 acquired the input / output signal states "X0.1: On," "Y0.0: On," "X10.1: On," and "Y10.0: On." The abnormality determination unit 130a uses the frequency components of the sounds of the fans 60(1) and 60(2) included in the equipment monitoring information acquired by the information acquisition unit 110a and the frequency components of the sounds of the fans 60(1) and 60(2) extracted from the storage area for "determination information" in the status table 151a-3 by the determination information extraction unit 170 to calculate the similarity between the frequency components of the sounds of the fans 60(1) and 60(2) as the absolute value of the difference between |295-300| = 5 and |605-600| = 5. If the calculated similarity between the fans 60(1) and 60(2) is smaller than a preset threshold, the abnormality determination unit 130a determines that the fans 60(1) and 60(2) are normal. On the other hand, if the calculated similarity between the fans 60(1) and 60(2) is equal to or greater than a preset threshold, the abnormality determination unit 130a determines that the fans 60(1) and 60(2) are abnormal.

[0065] As described above, in the first embodiment, variant 1-2 of the first embodiment, second embodiment, and variant 1-2 of the second embodiment, the PLCs 10 and 10A of the present disclosure can detect abnormalities that occur in control devices with high accuracy.

[0066] <Modifications> In the first embodiment, Modification 1-2 of the first embodiment, the second embodiment, and Modification 1-2 of the second embodiment described above, the PLCs 10 and 10A calculate the similarity using Equation 1 or the absolute value of the difference. However, this is not limiting. For example, the PLCs 10 and 10A may calculate the similarity based on any calculation method. However, if the similarity calculated by the calculation method increases as the device monitoring information and the monitoring images and sounds contained in the storage areas for the "determination information" become more similar to each other, it is preferable that the PLCs 10 and 10A determine that the similarity is similar when the similarity is equal to or greater than a predetermined threshold, and determine that the similarity is not similar when the similarity is less than the predetermined threshold.

[0067] The functions of the PLCs 10 and 10A in the first embodiment, the second embodiment, and the third embodiment can be implemented by hardware, software, or a combination of these. Here, "implemented by software" means that the functions are implemented by a computer reading and executing a program.

[0068] The program can be stored and supplied to a computer using various types of non-transitory computer-readable media. Non-transitory computer-readable media include various types of tangible storage media. Examples of non-transitory computer-readable media include magnetic recording media (e.g., flexible disks, magnetic tapes, hard disk drives), magneto-optical recording media (e.g., magneto-optical disks), CD-ROMs (Read Only Memory), CD-Rs, CD-R / Ws, and semiconductor memories (e.g., mask ROMs, PROMs (Programmable ROMs), EPROMs (Erasable PROMs), flash ROMs, and RAMs). The program may be provided to the computer by various types of transient computer-readable media. Examples of transient computer-readable media include electrical signals, optical signals, and electromagnetic waves. The transient computer-readable media can provide the program to the computer via a wired communication path such as an electrical wire or optical fiber, or via a wireless communication path.

[0069] The step of executing the program recorded on the recording medium includes not only processes that are performed in chronological order, but also processes that are not necessarily performed in chronological order but are performed in parallel or individually. Also, the step of writing the program may be performed by cloud computing.

[0070] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values ​​or mathematical expressions are used in the description of the above-described embodiments.

[0071] The following supplementary note is further disclosed regarding the above-described embodiment and modified examples. (Supplementary Note 1) The PLC device (10) is a PLC device for controlling controlled devices (35, 50, 60, 60(1), 60(2)), and includes an information acquisition unit (110) that acquires device monitoring information including at least a monitoring image or sound related to the controlled devices (35, 50, 60, 60(1), 60(2)), and a control unit (110) that determines the state of the controlled devices (35, 50, 60, 60(1), 60(2)) based on the device monitoring information acquired by the information acquisition unit (110) for each determination information including at least one monitoring image or sound related to when the controlled devices (35, 50, 60, 60(1), 60(2)) are in a normal state. The control system includes a signal state conversion unit (120) that converts the state of an input / output signal based on a state table (151) that links the states of the input / output signals related to the devices (35, 50, 60, 60(1), 60(2)), an abnormality determination unit (130) that compares the state of the input / output signal converted by the signal state conversion unit (120) with the state of the input / output signal at the time when the device monitoring information is acquired by the information acquisition unit (110) and determines whether or not the devices (35, 50, 60, 60(1), 60(2)) to be controlled are abnormal based on the comparison result, and an abnormality notification unit (140) that notifies the determination result of the abnormality determination unit (130). (Supplementary Note 2) In the PLC device (10) described in Supplementary Note 2, the signal state conversion unit (120) refers to the state tables (151, 151-1, 151-2, 151-3), calculates the degree of similarity with the equipment monitoring information acquired by the information acquisition unit (110), determines whether or not there is similarity based on a predetermined threshold, and if it is determined that there is similarity, extracts determination information and converts the equipment monitoring information into the state of an input / output signal linked to the extracted determination information.(Supplementary Note 3) The PLC device (10A) is a PLC device that controls devices (35, 50, 60, 60(1), 60(2)) that are to be controlled, and includes a signal state acquisition unit (160) that acquires states of input / output signals related to the devices (35, 50, 60, 60(1), 60(2)) that are to be controlled, and a state table (151a, 151-1, 151-2, 151-3) that associates determination information including at least a monitored image or sound with each state of one or more input / output signals related to the devices (35, 50, 60, 60(1), 60(2)) that are to be controlled when the devices (35, 50, 60, 60(1), 60(2)) are in a normal state, and acquires the input / output signals acquired by the signal state acquisition unit (160). an information acquisition unit (110a) that acquires equipment monitoring information including at least a monitoring image or sound related to the equipment (35, 50, 60, 60(1), 60(2)) to be controlled at the time when the state of the input / output signal is acquired by the signal state acquisition unit (160); an abnormality determination unit (130a) that compares the equipment monitoring information acquired by the information acquisition unit (110a) with the determination information extracted by the determination information extraction unit (170) and determines whether or not the equipment (35, 50, 60, 60(1), 60(2)) to be controlled is abnormal based on the comparison result; and an abnormality notification unit (140) that notifies the determination result of the abnormality determination unit (130a). (Supplementary Note 4) In the PLC device (10A) described in Supplementary Note 3, the abnormality determination unit (130a) calculates the similarity between the equipment monitoring information acquired by the information acquisition unit (110a) and the judgment information extracted by the judgment information extraction unit (170), and determines whether or not the equipment to be controlled (35, 50, 60, 60(1), 60(2)) is abnormal based on the calculated similarity.

[0072] 1 Abnormality monitoring system 10, 10A PLC 110, 110a Information acquisition unit 120 Signal state conversion unit 130, 130a Abnormality judgment unit 140 Abnormality notification unit 150, 150a Memory unit 150, 150-1, 150-2, 150-3, 150a State table 160 Signal state acquisition unit 170 Determination information extraction unit 20 Machine tool 25 Operation panel 30 Safety fence 31 Door 35 Opening / closing sensor 40 Monitoring camera 50 LED 60, 60 (1), 60 (2) Fan 70, 70a Operation panel 80 Microphone

Claims

1. A PLC device that controls equipment to be controlled, comprising: an information acquisition unit that acquires equipment monitoring information including at least monitoring images or sounds related to the equipment to be controlled; a signal state conversion unit that converts the state of the equipment to be controlled based on the equipment monitoring information acquired by the information acquisition unit into the state of the input / output signals based on a state table in which the state of the input / output signals related to the equipment to be controlled is linked to each piece of judgment information including at least one or more monitoring images or sounds related to when the equipment to be controlled is in a normal state; an abnormality judgment unit that compares the state of the input / output signals converted by the signal state conversion unit with the state of the input / output signals at the time the equipment monitoring information was acquired by the information acquisition unit, and judges whether the equipment to be controlled is abnormal based on the comparison result; and an abnormality notification unit that notifies the judgment result of the abnormality judgment unit.

2. The PLC device of claim 1, wherein the signal state conversion unit refers to the state table, calculates the degree of similarity with the equipment monitoring information acquired by the information acquisition unit, determines whether or not there is similarity based on a predetermined threshold, and if it is determined that there is similarity, extracts the judgment information and converts the equipment monitoring information into the state of the input / output signal linked to the extracted judgment information.

3. A PLC device that controls equipment to be controlled, comprising: a signal state acquisition unit that acquires the states of input / output signals related to the equipment to be controlled; a judgment information extraction unit that references a state table in which judgment information including at least a monitoring image or sound is linked to each state of one or more input / output signals related to the equipment to be controlled when the equipment to be controlled is in a normal state, and extracts the judgment information linked to the states of the input / output signals acquired by the signal state acquisition unit; an information acquisition unit that acquires equipment monitoring information including at least a monitoring image or sound related to the equipment to be controlled at the time the states of the input / output signals are acquired by the signal state acquisition unit; an abnormality judgment unit that compares the equipment monitoring information acquired by the information acquisition unit with the judgment information extracted by the judgment information extraction unit, and judges whether the equipment to be controlled is abnormal based on the comparison result; and an abnormality notification unit that notifies the judgment result of the abnormality judgment unit.

4. The PLC device of claim 3, wherein the abnormality judgment unit calculates the similarity between the equipment monitoring information acquired by the information acquisition unit and the judgment information extracted by the judgment information extraction unit, and judges whether the equipment to be controlled is abnormal based on the calculated similarity.

Images