JP7504331B1 - Industrial Control Systems - Google Patents

Abstract

Each of the controllers included in the industrial control system is equipped with an information recording unit (2) that records first individual identification information including its own individual identification information and second individual identification information including individual identification information of a second controller that is another controller connected to the first controller, an individual identification information transmitting unit (3) that transmits the first individual identification information to the second controller, an individual identification information comparing unit (4) that, upon receiving the second individual identification information from the second controller, compares the second individual identification information recorded in the information recording unit (2) with the received second individual identification information, and, if the comparison results in a difference, determines that the second controller has been replaced.

Description

This disclosure relates to industrial control systems used in industrial systems such as machine tools, mounting machines, conveyors, and robots.

In industrial systems that combine machine tools, mounting machines, conveyors, robots, or a combination of these, multiple controllers work together to fulfill their functions and perform machining and work. Here, a controller refers to a device that has the function of storing and executing commands and communicating with the outside. For example, machine tools such as machining centers, NC (Numerical Control) lathes, laser processing machines, and electric discharge machines are industrial systems that are composed of multiple controllers, such as one numerical control device, multiple motor drive devices, and multiple position detection devices. The numerical control device analyzes and executes the machining program, communicates with the motor drive device, and outputs motor drive commands for each motor. The motor drive device receives drive commands from the numerical control device, drives the motor, and executes a program that controls the motor position and speed to follow the motor drive command. The position detection device is built into the motor, executes a program that reads the encoder position, and transmits it to the motor drive device. In this way, multiple controllers work together to allow the machine tool to perform machining.

If a controller in an industrial system fails, the industrial system can be restored by replacing the failed controller. However, for example, if a controller is replaced at the product's installation site without the intention of the product manufacturer or product manager, the product manufacturer or product manager will not be able to identify the replaced controller or know the usage status of each controller.

To address this issue, in Patent Document 1, an IC (Integrated Circuit) tag is provided on each of the controllers that make up the product, and the controller's identification information and usage history information are recorded on each IC tag. When the power is turned on, for example, a management device obtains the controller's identification information recorded on each IC tag, and if the obtained controller's identification information has changed from the previous controller's identification information, it detects that the controller has been replaced.

JP 2012-79221 A

However, in the technology described in Patent Document 1, the identification information and usage history information of multiple controllers are centrally managed by a management device, and if, for example, the management device is replaced, there is no other device that manages the identification information and usage history information of the management device, and it is therefore impossible to detect that the management device has been replaced. This poses the problem of low reliability in detecting replacement.

The present disclosure has been made in consideration of the above, and aims to obtain an industrial control system that can detect controller replacement throughout the entire system with high accuracy and has highly reliable replacement detection.

In order to solve the above-mentioned problems and achieve the object, the industrial control system of the present disclosure functions by connecting three or more industrial controllers having individual identification information. Each of the multiple industrial controllers includes a recording unit that records first individual identification information including its own individual identification information and second individual identification information including individual identification information of a second industrial controller that is another industrial controller connected to the first industrial controller, a transmitting unit that transmits the first individual identification information to the second industrial controller, a comparing unit that compares the second individual identification information recorded in the recording unit with the received second individual identification information when the second individual identification information is received from the second industrial controller, a determining unit that determines that the second industrial controller has been replaced if the results of the comparison are different, and an updating unit that updates the second individual identification information recorded in the recording unit if the results of the comparison are different. The industrial control system includes an identifying device that identifies the replaced industrial controller by majority decision using the first individual identification information and the second individual identification information recorded in the recording units of the multiple industrial controllers.

The industrial control system disclosed herein has the advantage that controller replacement can be detected with high accuracy throughout the system, and replacement detection is highly reliable.

FIG. 1 is a block diagram showing an example of a configuration of a numerically controlled machine tool according to a first embodiment. FIG. 1 is a block diagram showing an example of a hardware configuration of a controller included in a numerically controlled machine tool according to a first embodiment; FIG. 1 is a block diagram showing a system configuration of a numerically controlled machine tool according to a first embodiment in terms of a controller function. FIG. 1 is a block diagram showing an example of a functional configuration of an exchange detection function unit implemented in each controller included in a numerically controlled machine tool according to a first embodiment; FIG. 1 is a diagram showing an example of individual identification information recorded in an information recording unit of the numerical control device according to the first embodiment; FIG. 1 is a diagram showing an example of individual identification information recorded in an information recording unit of the motor drive device according to the first embodiment; 1 is a flowchart showing an operation of an exchange detection function unit of each controller included in a numerically controlled machine tool according to a first embodiment. FIG. 11 is a block diagram showing a functional configuration of an exchange detection function unit implemented in each controller included in a numerically controlled machine tool according to a second embodiment. FIG. 13 is a diagram showing an example of individual identification information recorded in an information recording unit of the numerical control device according to the second embodiment; 11 is a flowchart showing the operation of an exchange detection function unit of each controller included in a numerically controlled machine tool according to a second embodiment. FIG. 13 is a block diagram showing a functional configuration of an exchange detection function unit implemented in each controller included in a numerically controlled machine tool according to a third embodiment. FIG. 13 is a diagram showing an example of individual identification information recorded in an information recording unit of the numerical control device according to the third embodiment; FIG. 13 is a block diagram showing a functional configuration of an exchange detection function unit implemented in each controller included in a numerically controlled machine tool according to a fourth embodiment. FIG. 13 is a diagram showing an example of individual identification information recorded in an information recording unit of the numerical control device according to the fourth embodiment; FIG. 13 is a block diagram showing an example of an industrial system having a numerically controlled machine tool according to a fifth embodiment. FIG. 13 is a diagram showing an example of individual identification information used in the production system according to the fifth embodiment.

Below, the industrial control system relating to the embodiment is described in detail with reference to the drawings.

Embodiment 1.
1 is a block diagram showing an example of a configuration of a numerically controlled machine tool 10 according to a first embodiment. The numerically controlled machine tool 10 is an example of an industrial control system. The numerically controlled machine tool 10 is an industrial machine that removes material from a workpiece using a tool to achieve a desired shape, and executes machining operations based on a machining program.

The numerically controlled machine tool 10 has one spindle motor 17 that drives the spindle, and three servo motors 16a, 16b, and 16c that drive the relative positions of the tool and workpiece in the three axial directions of X, Y, and Z. The spindle motor 17 and servo motors 16a, 16b, and 16c rotate by receiving power from a power line (not shown). The servo motors 16a, 16b, and 16c and the spindle motor 17 are fitted with position detectors 14a, 14b, 14c, and 14d that detect the rotation angle of each motor for feedback control.

The motor rotation angles detected by the position detectors 14a, 14b, 14c, and 14d are sent to the motor drivers 12a, 12b, and 12c for control. The motor driver 12a controls the positions of the X-axis servo motor 16a and the Y-axis servo motor 16b, the motor driver 12b controls the Z-axis servo motor 16c, and the motor driver 12c controls the spindle motor 17. The motor drivers 12a, 12b, and 12c are connected in order to the numerical control device 11 by optical communication cables 15.

The numerical control device 11 analyzes the machining program, calculates commands for each motor to execute the programmed machining, and transmits the calculated commands to the motor drive devices 12a, 12b, and 12c. The motor drive device 12c and the converter device 13 are connected via a converter communication cable 18. The converter device 13 supplies DC power to the motor drive devices 12a, 12b, and 12c via a bus bar (not shown).

In this specification, an industrial controller refers to a device that has the function of storing and executing programmed instructions and communicating with other devices. In the case of the numerically controlled machine tool 10, the numerical control device 11, the motor drive devices 12a, 12b, and 12c, the position detection devices 14a to 14d, and the converter device 13 correspond to the industrial controller. Hereinafter, the industrial controller will be simply referred to as the controller. In addition, the controllers that make up the numerically controlled machine tool 10 may include controllers of peripheral devices including I/O (Input/Output) devices (not shown), or display devices. All controllers that make up the numerically controlled machine tool 10 may be subject to replacement detection, or only controllers that significantly affect safety and performance may be subject to replacement detection.

2 is a block diagram showing an example of the hardware configuration of a controller included in the numerically controlled machine tool 10 according to the first embodiment. In the controller shown here, a processor 80 which is an arithmetic unit that executes instructions, a memory 81 which is a working area when executing instructions, a non-volatile memory 82 which is an auxiliary storage device, and a communication I/F (interface) 83 which is used for communication with an external controller are each connected by a bus. The memory 81 is also used as a working area for the processor 80.

The processor 80 includes a CPU (Central Processing Unit) and the like. The memory 81 includes a RAM (Random Access Memory), and the non-volatile memory 82 includes a HDD (Hard Disk Drive), an SSD (Solid State Drive), and the like. However, the hardware configuration of the controller illustrated here is only an example, and for example, the processor 80 may be a FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit) instead of a CPU, and the non-volatile memory 82 may be an EEPROM (registered trademark) (Electrically Erasable Programmable Read-Only Memory), a flash memory, or the like. The non-volatile memory 82 may also be used as a working memory 81. Furthermore, the communication I/F 83 may be realized as a function within the CPU, or may be implemented as hardware having a CPU or ASIC dedicated to communication. Furthermore, a single controller may have multiple communication I/Fs 83 of different types. When the communication I/F 83 is implemented as separate hardware, examples include an Ethernet (registered trademark) communication I/F, an optical communication I/F, a serial communication I/F, or a wireless communication I/F. Examples of the wireless communication I/F include 5G (5th Generation Mobile Networks), Wi-Fi (registered trademark) (Wireless Fidelity), Bluetooth (registered trademark), and the like.

Figure 3 is a block diagram showing the system configuration of the numerically controlled machine tool 10 according to the first embodiment from the viewpoint of the controller functions. In the numerically controlled machine tool 10, the numerical control device 11 is the upper controller and controls the lower motor drive devices 12a, 12b, and 12c. Specifically, the numerical control device 11 outputs an X-axis position command and a Y-axis position command to the motor drive device 12a, a Z-axis position command to the motor drive device 12b, and a spindle rotation command to the motor drive device 12c.

The motor drivers 12a, 12b, and 12c have the role of controlling each motor connected to them according to commands from the numerical control device 11. Specifically, the motor driver 12a outputs an X-axis motor current to the servo motor 16a and outputs a Y-axis motor current to the servo motor 16b. The motor driver 12b outputs a Z-axis motor current to the servo motor 16c. The motor driver 12c outputs a spindle motor current to the spindle motor 17.

Position detectors 14a to 14d are connected to the motor drivers 12a, 12b, and 12c as lower-level controllers of the motor drivers 12a, 12b, and 12c. The position detectors 14a to 14d transmit the detected positions to the higher-level controllers, the motor drivers 12a, 12b, and 12c. Specifically, the position detector 14a outputs the X-axis position to the motor driver 12a, the position detector 14b outputs the Y-axis position to the motor driver 12a, the position detector 14c outputs the Z-axis position to the motor driver 12b, and the position detector 14d outputs the spindle rotation angle to the motor driver 12c.

The converter device 13 is connected to the numerical control device 11 as a controller independent of the motor drive devices 12a, 12b, and 12c. The converter device 13 outputs the power supply status to the numerical control device 11. In this way, the numerically controlled machine tool 10 is an industrial control system having a functional configuration with three hierarchical structures.

4 is a block diagram showing an example of the functional configuration of the replacement detection function unit 1a implemented in each controller included in the numerically controlled machine tool 10 according to the first embodiment. The replacement detection function unit 1a is implemented in all controllers included in the numerically controlled machine tool 10. In other words, the replacement detection function unit 1a is implemented in all current controllers constituting the numerically controlled machine tool 10, and is also implemented in a new controller to be replaced. However, the information recording unit 2 as a recording unit, the individual identification information transmission unit 3 as a transmission unit, the individual identification information comparison unit 4 as a comparison unit and a judgment unit, and the information update unit 5 as an update unit, which are components of the replacement detection function unit 1a, are implemented in all controllers included in the numerically controlled machine tool 10, but the identification unit 8 is implemented in one controller out of all controllers included in the numerically controlled machine tool 10. The identification unit 8, which will be described in detail later, has a function of identifying a replaced unit and is implemented in one controller that functions as an identification device.

The information recording unit 2 is implemented in a non-volatile memory. The information recording unit 2 records the controller program, information required to execute processing such as program parameters related to processing, and individual identification information used by the exchange detection function unit 1a.

Figure 5 is a diagram showing an example of individual identification information 20a recorded in the information recording unit 2 of the numerical control device 11 according to the first embodiment. Figure 6 is a diagram showing an example of individual identification information 20b recorded in the information recording unit 2 of the motor drive device 12a according to the first embodiment. Similar individual identification information is also recorded in other controllers and used for replacement detection, but hereinafter replacement detection of the numerical control device 11 and the motor drive device 12a will be described.

As shown in FIG. 5, the individual identification information 20a recorded in the information recording unit 2 of the numerical control device 11 includes a self-device information recording unit 21 in which the serial number of the own (numerical control device 11) is recorded. As shown in FIG. 6, the individual identification information 20b recorded in the information recording unit 2 of the motor drive device 12a includes a self-device information recording unit 21 in which the serial number of the own (motor drive device 12a) is recorded. The serial number is uniquely defined for each product and is a number that can identify an individual. The serial number may be composed of only numbers or a combination of a character string and numbers as long as it is information that can identify an individual controller. The own industrial controller (own controller) corresponds to the first industrial controller, and the controller connected to the own industrial controller (own controller) corresponds to the second industrial controller. The individual identification information of the first industrial controller corresponds to the first individual identification information, and the individual identification information of the second industrial controller corresponds to the second individual identification information.

The types of controllers included in the numerical control machine 10 and the connection form between each controller are predefined by parameters used in the numerical control device 11. For example, it is determined how many motor drive devices 12a, 12b, and 12c are connected to the numerical control device 11 in what order and in what connection form, and how many position detection devices 14a to 14d are connected to each motor drive device 12a, 12b, and 12c. Normally, this configuration is not changed once the numerical control machine 10 is shipped. In this example, as shown in FIG. 5, the individual identification information 20a of the information recording unit 2 of the numerical control device 11 includes the above-mentioned own device information recording unit 21 and the connected device information recording unit 22 in which the identification information of the connected device is recorded. The connected device information recording unit 22 includes the device names, serial numbers, and exchange detection flags as the first flags for the three motor drive devices 12a to 12c connected to the numerical control device 11. 6, like the individual identification information 20a, the individual identification information 20b of the information recording section 2 of the motor driving device 12a includes a host device information recording section 21 and a connected device information recording section 22. The connected device information recording section 22 includes device names, serial numbers, and exchange detection flags for the numerical control device 11 as the connected upper controller and the two position detection devices 14a, 14b as lower controllers.

The name of the connected device may be any type of information as long as the controller can uniquely recognize the name of the device. The replacement detection flag is recorded as 1 when the controller detects replacement, and 0 otherwise. In the pre-start stage when a controller is replaced from an old device to a new device and connected to another controller, the serial number of the new device is recorded in the self-device information recording section 21 of the individual identification information recorded in the information recording section 2 of the new device. In addition, the serial number of the controller that was previously connected just before the replacement, in other words, and the replacement detection flag of 0 are recorded in the connected device information recording section 22 of the individual identification information recorded in the information recording section 2 of the new device. If the new device is an unused product, nothing is recorded in the connected device information recording section 22, and it is in the initial state. However, with regard to the replacement detection flag, a process of forcibly writing 0 from outside may be performed before the replacement. For example, the information in the information recording section 2 may be rewritten using dedicated software, or a command to rewrite the replacement detection flag may be sent from an input device such as a keyboard (not shown) to overwrite the replacement detection flag.

Returning to the description of the configuration of the replacement detection function unit 1a in FIG. 4, the individual identification information transmission unit 3 transmits its own serial number recorded in the self-device information recording unit 21 of the information recording unit 2 to the other controller. In addition, the individual identification information transmission unit 3 of the controller in which the identification unit 8 is implemented transmits the determination result of the identification unit 8 to the other controller. The individual identification information comparison unit 4 receives the serial number transmitted from the controller connected to itself, calls up the serial number of the corresponding device recorded in the connected device information recording unit 22 of the information recording unit 2, and compares the received serial number with the serial number recorded in the connected device information recording unit 22. In addition, in communication between the controllers, the controller that receives the serial number can determine from which connected device it received the serial number. If the received serial number does not match the serial number recorded in the connected device information recording unit 22, the individual identification information comparison unit 4 determines that the connected device has been replaced and notifies the information update unit 5 of that effect. The information updating unit 5 records the serial number of the device newly connected to itself in the connected device information recording unit 22 of the information recording unit 2, and sets the exchange detection flag to 1. The information updating unit 5 also updates the record in the connected device information recording unit 22 of the information recording unit 2 based on the determination result of the identifying unit 8 or the determination result of the identifying unit 8 received from another controller. The function of the identifying unit 8 will be described in detail later.

Figure 7 is a flowchart showing the operation of the replacement detection function unit 1a of each controller included in the numerically controlled machine tool 10 according to the first embodiment. When each controller completes startup, it first establishes communication. Once communication is established and each controller is connected, each controller performs replacement detection. At the start of replacement detection, all controllers on the network notify the connected controller of their own serial numbers. Here, an example is explained in which each controller transmits its serial number in a predetermined order.

First, the individual identification information transmission unit 3 of the controller checks whether all transmissions and receptions are complete (step S1). If transmission of the serial numbers of all controllers has not been completed (step S1: No), the individual identification information transmission unit 3 of the controller checks whether it is its turn to transmit its own serial number (step S2). If it is its turn to transmit (step S2: Yes), the individual identification information transmission unit 3 of the controller transmits its own serial number (step S3). If it is not its turn to transmit (step S2: No), the individual identification information transmission unit 3 of the controller waits to receive a serial number from another controller connected to it (step S4). If it has received a serial number from a controller connected to it (step S5: Yes), the individual identification information transmission unit 3 of the controller transitions to step S1.

Steps S1 to S5 are one example of a method for mutually notifying serial numbers between connected controllers, and any exchange method may be used as long as serial numbers can be mutually notified between connected controllers. For example, the upper controller may collect the serial numbers of all controllers and notify all controllers of their serial numbers at once.

When all controllers have completed sending and receiving their serial numbers (step S1: Yes), the controller's individual identification information comparison unit 4 compares, for each controller that has received a serial number, whether the received serial number matches the serial number recorded in the connection device information recording unit 22 of the individual identification information of the information recording unit 2 (the serial number of the device connected to it) (step S6).

If the received serial number matches the recorded serial number (step S6: Yes), the controller's individual identification information comparison unit 4 determines that the connected controller has not been replaced and completes replacement detection.

If there is no serial number that matches the received serial number and the recorded serial number (step S6: No), the controller's individual identification information comparison unit 4 determines that the connected controller has been replaced and notifies the information update unit 5 of this fact.

The information update unit 5 records the serial numbers of the controllers that do not match in the above comparison, i.e., the serial numbers of the newly connected controllers, in the connection device information recording unit 22 of the individual identification information of the information recording unit 2, updates the replacement detection flag to 1 (step S7), and then completes the replacement detection. However, the replacement detection may be performed every time each controller is started, may be performed periodically, such as once a month or once every six months, or may be performed by an operator's operation input.

The identification of the replaced unit performed in the identification unit 8 will be described. In the numerically controlled machine tool 10 shown in FIG. 1, the motor drive unit 12a is assumed to be the replaced unit. Since the motor drive unit 12a is the replaced unit, the serial number of the replaced device is recorded in the self-device information recording section 21 of the individual identification information 20b of the information recording section 2 of the motor drive unit 12a. In addition, as described above, the connected device information recording section 22 of the individual identification information 20b of the information recording section 2 of the motor drive unit 12a records the serial number of the controller connected immediately before the replacement, a replacement detection flag of 0, or nothing is recorded, and it is in the initial state. On the other hand, the serial number of the device before the replacement as the motor drive unit 12a is recorded in the motor drive unit 12a column of the connected device information recording section 22 of the individual identification information 20a of the information recording section 2 of the numerical control device 11. Therefore, in the comparison process in the numerical control device 11, the serial number recorded in the column for the motor driving device 12a in the connection device information recording unit 22 does not match the serial number received from the motor driving device 12a. Also, in the comparison process in the motor driving device 12a, the serial numbers recorded in the columns for the numerical control device 11, the position detection device 14a, and the position detection device 14b in the connection device information recording unit 22 of the information recording unit 2 of the motor driving device 12a do not match the serial numbers received from the numerical control device 11, the position detection device 14a, and the position detection device 14b. Although the description of the operation in the position detection device 14a and the position detection device 14b is omitted, in this case, the numerical control device 11, the position detection device 14a, and the position detection device 14b detect that the motor driving device 12a has been replaced, and the motor driving device 12a detects that the numerical control device 11, the position detection device 14a, and the position detection device 14b have become the new connection destinations.

The individual identification information recorded in the information recording unit 2 of all the controllers constituting the numerically controlled machine tool 10 is transmitted to one of the multiple controllers constituting the numerically controlled machine tool 10 or to an external computer.

Here, the identification of the replaced unit is performed, for example, by one of the multiple controllers or an external computer. Hereinafter, one of the multiple controllers or the external computer that executes the identification process of the replaced unit will be referred to as the identified device. When the identified device is composed of one of the multiple controllers, the controller that becomes the identified device includes the identification unit 8 shown in FIG. 4.

The individual identification information of the information recording units 2 of all controllers constituting the numerically controlled machine tool 10 is transmitted to the identification unit 8 of the specific device. The specific device may be the numerical control device 11, which is the highest level controller, or another controller. Alternatively, it may be an external computer connected directly to the numerical control device 11 or via a network, or a computer in the cloud.

The identification unit 8 of the specific device determines which controller has been replaced, for example, by majority vote using the individual identification information transmitted from all controllers constituting the numerically controlled machine tool 10. The identification unit 8 of the specific device causes the information update unit 5 to update the contents of the individual identification information in the information recording unit 2 based on the judgment result. The identification unit 8 of the specific device also transmits the judgment result to all controllers. The information update unit 5 of each controller that receives the judgment result updates the contents of the individual identification information in the information recording unit 2 based on the judgment result. In other words, the controller that made the erroneous judgment of the replaced equipment corrects the contents of the individual identification information in the information recording unit 2 based on the judgment result of the majority vote. The judgment result of the specific device may be transmitted only to some of the controllers that made the erroneous judgment.

A specific example of the identification method will be described below. Here, it is assumed that, in the numerically controlled machine tool 10 shown in Fig. 1, only the motor drive unit 12a of the nine controllers shown in Fig. 3 is replaced. In addition, in the numerically controlled machine tool 10, the individual identification information of each controller is shared by all controllers belonging to the system, including not only directly connected controllers but also indirectly connected controllers.

For example, in the numerically controlled machine tool 10 shown in Figure 1, after the motor drive unit 12a is replaced, the connection device information recording unit 22 of the information recording unit 2 of the motor drive unit 12a newly incorporated into the numerically controlled machine tool 10 records information about the controller of the other system that was previously connected. Therefore, in the motor drive unit 12a newly incorporated into the numerically controlled machine tool 10, the fact that the controller of the other system that was previously connected has been replaced is detected in the replacement device detection process at startup shown in Figure 7.

On the other hand, in each controller other than the motor driving unit 12a, there is a mismatch between the serial number transmitted from the motor driving unit 12a, the serial number recorded in the motor driving unit 12a column of the connection device information recording unit 22 possessed by the respective controller, and the serial number received from the motor driving unit 12a newly incorporated into the numerically controlled machine tool 10, and it is detected that the motor driving unit 12a has been replaced.

The identification device then collects individual identification information from all of the controllers that make up the numerically controlled machine tool 10. After collecting the individual identification information, the identification unit 8 of the identification device refers to the individual identification information received from each controller.

At this time, the identification unit 8 of the specific device refers to the individual identification information received from the motor drive unit 12a and recognizes that the connection destination has been changed to the controller belonging to the numerically controlled machine tool 10. Specifically, the identification unit 8 of the specific device recognizes that the connection destination for the motor drive unit 12a has been changed to the controller belonging to the numerically controlled machine tool 10 because the exchange detection flags of the records corresponding to the numerical control unit 11, the position detection unit 14a, and the position detection unit 14b shown in Figure 3 are set to 1 in the individual identification information.

Next, the identification unit 8 of the specific device refers to the individual identification information received from the eight controllers other than the motor drive unit 12a and recognizes that the motor drive unit 12a has been replaced. Specifically, the identification unit 8 of the specific device recognizes that the motor drive unit 12a has been replaced because the replacement detection flag of the record corresponding to the motor drive unit 12a newly installed in the numerically controlled machine tool 10 is set to 1 in the individual identification information.

The identification unit 8 of the identification device ultimately determines that the motor driving device 12a has been replaced based on the recognition result based on the individual identification information received from the motor driving device 12a and the recognition result based on the individual identification information received from the eight controllers other than the motor driving device 12a.

According to this method of identification, even if, for example, one of the eight controllers makes a false detection and recognizes that the motor drive unit 12a has not been replaced, it is possible to determine by majority vote that the motor drive unit 12a has been replaced because the replacement detection flags of the other seven controllers are set to 1.

In addition, when an industrial control system is composed of only one pair of controllers, it is difficult to determine which controller has been replaced. However, in the first embodiment, since all controllers record the serial numbers of the controllers connected to each of them, for example, in a system consisting of three controllers, if only one controller is replaced, the other two controllers record their respective serial numbers, but the newly replaced controller does not have any information on the other two controllers, so it is possible to identify which controller has been replaced. Similarly, for example, even if two controllers are replaced in a system consisting of five controllers, the other three controllers record their respective serial numbers, and the replaced two controllers do not have any information on the three controllers, so it is possible to identify which controller has been replaced by majority vote.

At the time of starting up the numerically controlled machine tool 10, for example, the controller C, which is not directly connected to the controller A, may receive the serial number associated with the controller A via the controller B, which is directly connected to the controller A and the controller C, and record the result according to the above-mentioned comparison result in the individual identification information of the information recording unit 2. In this way, it is possible to avoid a situation in which the number of directly connected controllers is small and it becomes difficult to determine the replaced controller by majority vote. For example, if the position detection devices 14a to 14c connected to the motor drives 12a and 12b are also recorded with the serial number of the numerical control device 11, and the motor drive 12b is also recorded with the serial number of the motor drive 12a, when the motor drive 12a is replaced, while there are many controllers recorded with the motor drive 12a being replaced, only the motor drive 12a is recorded with the other controller as the new connection destination. As a result, even if there are few directly connected controllers, the replacement between the controllers can be determined by majority vote.

Thus, according to embodiment 1, since the identifying device identifies the replaced controller based on the mutual judgment results of mutual communication between multiple controllers, the replacement of the controller can be detected with high accuracy throughout the system, and the effect of highly reliable replacement detection is achieved. Even if a higher-level controller is replaced, it is possible to identify the replaced controller with high accuracy. Even if multiple controllers are replaced, if less than half of the controllers in the industrial control system are replaced, the correct majority vote result is obtained, so it is possible to accurately determine that multiple controllers have been changed or replaced. However, the case where more than half of the controllers are replaced will be described in embodiment 2.

Embodiment 2.
The controller to which the exchange detection function of the second embodiment is applied is a controller constituting the same numerically controlled machine tool 10 as in the first embodiment. Hereinafter, the second embodiment will be described, focusing on the differences from the first embodiment.

Figure 8 is a block diagram showing the functional configuration of an exchange detection function unit 1b implemented in each controller included in a numerically controlled machine tool 10 according to embodiment 2. In the exchange detection function unit 1b of embodiment 2, a date and time measurement unit 6 is added, and an information update unit 5b records individual identification information including date and time information measured by the date and time measurement unit 6 in an information recording unit 2.

9 is a diagram showing an example of individual identification information 20c recorded in the information recording unit 2 of the numerical control device 11 according to the second embodiment. In the first embodiment, when the connected controller is replaced, the serial number is overwritten in the connection device information recording unit 22 of the information recording unit 2. In contrast, in the second embodiment, when the connected controller is replaced, the serial number history is recorded in the connection device information recording unit 22 of the information recording unit 2. That is, in the second embodiment, when the connected controller is replaced, the connection device information recording unit 22 of the information recording unit 2 records the serial number of the previously connected device and the serial number of the currently replaced device. In addition, in the second embodiment, the connection device information recording unit 22 of the information recording unit 2 records the date and time when the controller replacement is detected. FIG. 9 shows a case where the motor drive device 12a is replaced, and for the motor drive device 12a, the connection device information recording unit 22 of the information recording unit 2 of the numerical control device 11 records the serial number and detection date and time of the previously connected device and the serial number and detection date and time of the currently replaced device.

Figure 10 is a flowchart showing the operation of the exchange detection function unit 1b of each controller included in the numerically controlled machine tool 10 according to the second embodiment. The operation contents from step S1 to step S5 are the same as those in the first embodiment, and the overlapping explanations will be omitted. When all controllers have completed the transmission and reception of serial numbers (step S1: Yes), the individual identification information comparison unit 4 of the controller compares the received serial numbers of all controllers that have received their serial numbers with the serial numbers recorded in the connection device information recording unit 22 of the information recording unit 2 to determine whether they match, and determines whether there is a device that is connected for the first time and is different from the controllers connected at any time in the past (step S6b). When there is no device that is connected for the first time (step S6b: No), the individual identification information comparison unit 4 of the controller determines that all connected controllers have not been replaced, and completes the exchange detection. When there is a device that is connected for the first time (step S6b: Yes), the individual identification information comparison unit 4 of the controller determines that the device that is connected for the first time among the connected controllers has been replaced, and notifies the information update unit 5 of that effect. The information update unit 5 records the serial number of the newly connected controller in the connection device information recording unit 22 of the information recording unit 2, updates the exchange detection flag to 1, and records the current date and time when the exchange was detected as date and time information (step S7b), and then completes the exchange detection.

The identification device uses the individual identification information transmitted from each controller constituting the numerically controlled machine tool 10 to identify the replaced controller, for example by majority vote. For example, if three controllers are replaced in a system consisting of five controllers, the replacement detection flag will be 0 only between the two controllers that have not been replaced, and the replacement detection flag will be 1 between the other controllers. The identification device refers to the date and time information in the individual identification information transmitted from each controller. The date and time information of the two controllers that have not been replaced matches the past date and time when the replacement was first detected. However, between the other controllers, the latest date and time information matches the current date and time, but all of the past date and time information does not match. The identification device determines that the two controllers with matching date and time information at the past date and time have not been replaced, and that the other three controllers have been replaced.

In this way, in embodiment 2, the date and time information is recorded in conjunction with the serial number, so if at least two controllers have not been replaced, the date and time information in the individual identification information of these two controllers that have not been replaced will match, and it will be possible to identify the replaced controller based on this, assuming that the majority of the controllers have been replaced.

Thus, according to embodiment 2, the individual identification information of previously connected controllers and the date and time of replacement are recorded, making it possible to identify the replaced controller more easily and with greater accuracy even when the majority of controllers have been replaced.

Embodiment 3.
The controller to which the exchange detection function of the embodiment 3 is applied is a controller constituting the same numerically controlled machine tool 10 as that of embodiment 1. Hereinafter, embodiment 3 will be described, focusing on the differences from embodiment 1.

Figure 11 is a block diagram showing the functional configuration of an exchange detection function unit 1c implemented in each controller included in a numerically controlled machine tool 10 according to embodiment 3. In the exchange detection function unit 1c of embodiment 3, a control mode receiving unit 7 is added, and an information updating unit 5c executes an updating operation in the information recording unit 2 based on the received information of the control mode receiving unit 7 and the comparison result of the individual identification information comparing unit 4.

In a numerically controlled machine tool, the motor or motor drive device to be used may be switched depending on the control mode. For example, the spindle motor 17 and spindle position detection device 14d connected to the motor drive device 12c may be switched using an electromagnetic switch or electromagnetic contactor depending on the spindle rotation speed, and the power supply to the motor drive device that drives the transport device and the motor connected to it may be turned off when the transport device is not in use.

In such a case, it is necessary to manage the individual identification information of the connected controller according to the control mode. FIG. 12 is a diagram showing an example of the individual identification information 20c recorded in the information recording unit 2 of the numerical control device 11 according to the third embodiment. In the individual identification information 20c, in addition to the own device information recording unit 21 in which the own serial number is recorded, the connected device information recording unit 22 in which the serial number and the exchange detection flag of the connected controller are recorded is managed for each control mode. The first table 22a, which is the connected device information recording unit 22, records the serial numbers and the exchange detection flags of the motor driving devices 12a and 12b, which are the controllers connected in the first control mode. The second table 22b, which is the connected device information recording unit 22, records the serial numbers and the exchange detection flags of the motor driving devices 12a, 12b, and 12c, which are the controllers connected in the second control mode.

When the control mode receiving unit 7 notifies the user that the control mode is the first control mode, the exchange detection unit 1c refers to the first table 22a to determine whether or not an exchange has been detected. On the other hand, when the control mode is notified, the exchange detection unit 1c refers to the second table 22b to perform exchange detection.

Thus, according to embodiment 3, when the connected controller changes depending on the control mode, the individual identification information of the controller connected according to the control mode is managed separately, making it possible to accurately detect replacement even when the connected controller changes depending on the control mode.

Embodiment 4.
The controller to which the replacement detection function of the embodiment 4 is applied is a controller constituting the same numerically controlled machine tool 10 as that of embodiment 1. Hereinafter, embodiment 4 will be described, focusing on the differences from embodiment 1.

Figure 13 is a block diagram showing the functional configuration of an exchange detection function unit 1d implemented in each controller included in a numerically controlled machine tool 10 according to embodiment 4. The exchange detection function unit 1d of embodiment 4 has an information update unit 5d that receives a genuine product notification flag as a second flag. The other configuration is the same as in embodiment 1, and duplicated explanations will be omitted.

In industrial controllers, when a failure occurs, the failed controller may be repaired and then replaced. In such a case, no problem occurs if the controller is replaced with a new one or one that has been repaired using the correct procedure, but problems may occur if the controller is replaced with one that has been repaired using an unauthorized method. Therefore, when a controller is replaced with a correct one, a genuine product notification flag that notifies the user that the replacement is a genuine one is sent to the information update unit 5d of the replaced controller from an input device such as a keyboard or HMI (human machine interface) included in the numerically controlled machine tool 10. The information update unit 5d of the replaced controller associates the serial number of the newly connected controller with the genuine product notification flag and records them in the information recording unit 2.

The genuine product notification flag may be sent, for example, by inputting a specific password, or may be sent via a network such as the Internet when authentication is performed via a server managed by the manufacturer, such as the cloud or edge. The genuine product notification flag may also be sent during the first communication after the replacement, or an operation to notify the genuine product notification flag may be performed at any time after the replacement.

Figure 14 is a diagram showing an example of individual identification information 20d recorded in the information recording unit 2 of the numerical control device 11 according to the fourth embodiment. In the individual identification information 20d, in addition to the serial number and the replacement detection flag, the non-genuine product flag is recorded in the connection device information recording unit 22. Here, if the genuine product notification flag is received, the non-genuine product flag is recorded as 0, and if the genuine product notification flag is not received, the non-genuine product flag is recorded as 1. In this individual identification information 20d, the motor drive unit 12a has not been replaced. The motor drive unit 12b has been replaced once, so the replacement detection flag is 1, but the genuine product notification flag has been received, so the non-genuine product flag is 0. On the other hand, the motor drive unit 12c has not received the genuine product notification flag, so the non-genuine product flag is recorded as 1, and it can be seen that the controller was replaced without going through genuine means.

In FIG. 14, the serial numbers of the position detectors 14a, 14b, ..., the replacement detection flag, and the non-genuine product flag are recorded in the connection device information recording section 22 of the information recording section 2 of the numerical control device 11. In the fourth embodiment, as described in the first embodiment, the serial numbers of the position detectors 14a, 14b, 14c, 14d that are not directly connected to the numerical control device 11 are transmitted from the position detectors 14a, 14b, 14c, 14d via the motor drivers 12a, 12b, 12c that are directly connected to the numerical control device 11. The serial number of the numerical control device 11 is also transmitted to the position detectors 14a, 14b, 14c, 14d via the motor drivers 12a, 12b, 12c.

In embodiment 4, an unauthorized replaced controller can be detected, so that, for example, if an unauthorized controller is included in the system, a warning message may be displayed, operation may be stopped, or the operable speed and motor current value may be limited to prevent an accident from occurring.

Thus, according to embodiment 4, it is possible to determine whether the replaced controller is genuine or non-genuine.

Embodiment 5.
15 is a block diagram showing an example of an industrial system having a numerically controlled machine tool according to a fifth embodiment. The industrial system according to the fifth embodiment is applied to a production system 100. The production system 100 includes two numerically controlled machine tools 10a and 10b, a robot device 60, a transport device 62, and a PLC (Programmable Logic Controller) device 70 which is a production management device. The PLC device 70 controls the numerically controlled machine tools 10a and 10b, the robot device 60, and the transport device 62.

The numerically controlled machine tool 10a includes a numerical control device 11a, a motor drive device (not shown), and a position detection device (not shown). The numerically controlled machine tool 10b includes a numerical control device 11b, a motor drive device (not shown), and a position detection device (not shown). The robot device 60 includes a robot control device 61 that controls a robot (not shown). The transport device 62 includes a PLC device 63 that controls a transport mechanism (not shown). The numerically controlled machine tools 10a and 10b are connected to a PLC device 70, which is a higher-level controller, via the numerical control devices 11a and 11b. The robot device 60 is connected to the PLC device 70 via the robot control device 61. The transport device 62 is connected to the PLC device 70 via the PLC device 63.

In embodiment 1, all controllers are connected using the same communication method, but in embodiment 5, each controller is connected using a different communication method. The numerically controlled machine tool 10a and the PLC device 70 are connected using Ethernet communication. The robot device 60 and the PLC device 70 are connected using Ethernet communication. The numerical control device 11b is connected to the PLC device 70 via wireless communication. The PLC device 63 of the transport device 62 is connected to the PLC device 70 via dedicated PLC communication.

Since the numerical control device 11a and the PLC device 63 use different communication methods, they cannot communicate directly, but if the higher-level controller, PLC device 70, acts as an intermediary, individual identification information can be transmitted and received between the numerical control device 11a and the PLC device 63. For example, information on all controllers (numerical control devices 11a, 11b, robot control device 61, PLC devices 63, 70) is recorded in the information recording unit 2 of the PLC device 70, and the individual identification information of all controllers is transmitted in the individual identification information transmitting unit 3 via multiple communication interfaces possessed by the PLC device 70, making it possible to share individual identification information even between controllers connected using different communication methods.

In addition, in the first embodiment, a serial number that is uniquely set for each controller is used as the individual identification information, but some controllers may not have a serial number, and there may be two or more controllers that have the same information, such as a lot number. Therefore, in the fifth embodiment, individual identification is performed using information other than the serial number.

Figure 16 is a diagram showing an example of individual identification information 20e used in the production system 100 according to the fifth embodiment. The individual identification information 20e includes the name of the device, the device type, the total operating time, the total number of alarms, and the non-genuine product flag for the device itself (the device itself) and the connected devices (the first device, the second device, and the third device). The total operating time is the cumulative value of the time the device is in operation. The total number of alarms is the cumulative value of the number of alarms. For controllers that do not have a serial number, multiple pieces of information about the device are combined to identify the controller. For example, by combining multiple pieces of information such as the total operating time and the total number of alarms, it is possible to create information that is as unique as possible for identifying the controller.

Other information for identifying a controller may be a combination of information such as the time of last communication, the total number of parts processed, and the time of the previous failure. Since the individual identification information 20e is used to determine whether a controller connected in the production system 100 has been replaced, the information does not have to be completely unique, such as a serial number, as long as it is possible to detect that the controller before and after replacement are different controllers.

Thus, according to the fifth embodiment, individual identification information is communicated between all controllers via a higher-level controller that is connected to all controllers via multiple different communication interfaces, so that controller replacement can be detected even in production system 100 where controllers with different communication methods are connected. Also, by combining multiple pieces of information such as the total operating time, the total number of alarms, the time of the last communication, the total number of parts processed, and the time of the previous failure, it is determined whether the controller before and after replacement are different individuals, so that even if a controller does not have unique information such as a serial number, it can be detected that it has been properly replaced.

The configurations shown in the above embodiments are examples of the contents of the present disclosure, and may be combined with other known technologies, or the embodiments may be combined with each other, or parts of the configurations may be omitted or modified without departing from the gist of the present disclosure.

1a, 1b, 1c, 1d Exchange detection function unit, 2 Information recording unit, 3 Individual identification information transmission unit, 4 Individual identification information comparison unit, 5, 5b, 5c, 5d Information update unit, 6 Date and time measurement unit, 7 Control mode receiving unit, 8 Identification unit, 10, 10a, 10b Numerical control machine tool, 11, 11a, 11b Numerical control device, 12a, 12b, 12c Motor drive device, 13 Converter device, 14a, 14b, 14c, 14d Position detection device, 15 Optical communication cable, 16a, 16b, 16c Servo motor, 17 Spindle motor, 18 Converter communication cable, 20a, 20b, 20c, 20d, 20e Individual identification information, 21 Self device information recording unit, 22 Connected device information recording unit, 22a First table, 22b Second table, 60 Robot device, 61 Robot control device, 62 conveyance device, 63, 70 PLC device, 80 processor, 81 memory, 82 non-volatile memory, 83 communication I/F, 100 production system.

Claims (9)

An industrial control system in which three or more industrial controllers having individual identification information are connected to function,
Each of the plurality of industrial controllers
a recording unit that records first individual identification information including its own individual identification information and second individual identification information including individual identification information of a second industrial controller that is another industrial controller connected to the first industrial controller;
A transmitter that transmits the first individual identification information to the second industrial controller;
a comparison unit that, when receiving the second individual identification information from the second industrial controller, compares the second individual identification information recorded in the recording unit with the received second individual identification information;
a determination unit that determines that the second industrial controller has been replaced when the comparison result is different;
and an update unit that updates the second individual identification information recorded in the record unit when the comparison result is different,
an identification device that identifies a replaced industrial controller by majority decision using the first individual identification information and the second individual identification information recorded in the recording units of a plurality of the industrial controllers . 2. The industrial control system of claim 1, wherein the second industrial controller includes an industrial controller directly connected to the first industrial controller and an industrial controller indirectly connected to the first industrial controller via an industrial controller directly connected to the first industrial controller. 3. The industrial control system according to claim 1, wherein the individual identification information is a serial number. 3. The industrial control system according to claim 1, wherein the second individual identification information includes a first flag indicating whether the second industrial controller has been replaced. 3. The industrial control system according to claim 1 , wherein the second individual identification information includes date and time information indicating a date and time of replacement of the second industrial controller. 3. The industrial control system according to claim 1 , wherein the second individual identification information includes a second flag indicating whether the product is genuine or non-genuine. 3. The industrial control system according to claim 1, wherein the second individual identification information includes individual identification information of the second industrial controller connected in a first control mode and individual identification information of the second industrial controller connected in a second control mode. The individual identification information is
3. The industrial control system according to claim 1 , further comprising at least two of the following: power-on time, number of alarms, last communication time, total number of processed parts, and last failure time. 3. The industrial control system according to claim 1, wherein each of the industrial controllers includes a numerical control device which is a higher-level controller, a motor drive device which is a lower-level controller connected to the numerical control device, and a position detection device connected to the motor drive device.

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