Industrial control system

Abstract

This industrial control system includes controllers each of which comprises: an information recording unit (2) that records first individual identification information, which includes individual identification information for the relevant controller, and second individual identification information, which includes individual identification information for a second controller that is a different controller connected to a first controller; an individual identification information transmission unit (3) that transmits the first individual identification information to the second controller; an individual identification information comparison unit (4) that, upon receiving second individual identification information from the second controller, compares the second individual identification information recorded in the information recording unit (2) to the received second individual identification information; and an individual identification information comparison unit (4) that determines that the second controller has been replaced if the results of the comparison are different.

Description

Industrial Control Systems

[0001] The present disclosure relates to an industrial control system used in industrial systems such as machine tools, mounting machines, conveyors, and robots.

[0002] In industrial systems that combine machine tools, mounting machines, conveyors, robots, or multiple of these, multiple controllers work together to perform their functions and perform machining and other tasks. Here, a controller refers to a device that stores and executes commands and communicates with external devices. For example, machine tools such as machining centers, NC (Numerical Control) lathes, laser processing machines, and electrical discharge machines are industrial systems that consist of multiple controllers, such as a numerical control device (NC), multiple motor drivers, and multiple position detectors. The NC analyzes and executes the machining program, communicates with the motor drivers, and outputs motor drive commands for each motor. The motor drivers receive drive commands from the NC, drive the motors, and execute programs to control the motor position and speed so that they follow the motor drive commands. The position detectors, built into the motors, execute programs that read the encoder position and transmit the data to the motor drivers. This collaboration of multiple controllers enables machine tools to perform machining.

[0003] 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 installation site without the intention of the product manufacturer or product administrator, the product manufacturer or product administrator will not be able to identify the replaced controller or know the usage status of each controller.

[0004] To address this problem, in Patent Document 1, an IC (Integrated Circuit) tag is provided for each controller that makes 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 acquires the controller's identification information recorded on each IC tag, and if the acquired controller's identification information has changed from the previous controller's identification information, it detects that the controller has been replaced.

[0005] JP 2012-79221 A

[0006] 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 the management device is replaced, for example, 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.As a result, there is an issue of low reliability in replacement detection.

[0007] The present disclosure has been made in view of the above, and aims to provide an industrial control system that can detect controller replacement throughout the entire system with high accuracy and that provides highly reliable replacement detection.

[0008] In order to solve the above-mentioned problems and achieve the object, the industrial control system of the present disclosure functions by connecting a plurality of industrial controllers each having individual identification information, each of the plurality of industrial controllers including 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, upon 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, and a determining unit that, if the comparison results in a difference, determines that the second industrial controller has been replaced.

[0009] The industrial control system of the present disclosure has the advantage that controller replacement can be detected with high accuracy throughout the entire system, and replacement detection is highly reliable.

[0010] FIG. 1 is a block diagram showing an example of a configuration of a numerically controlled machine tool according to a first embodiment; FIG. 2 is a block diagram showing an example of a hardware configuration of a controller included in the numerically controlled machine tool according to the first embodiment; FIG. 3 is a block diagram showing a system configuration of the numerically controlled machine tool according to the first embodiment from the viewpoint of the functions of the controller; FIG. 4 is a block diagram showing an example of a functional configuration of an exchange detection function unit implemented in each controller included in the numerically controlled machine tool according to the first embodiment; FIG. 10 is a block diagram showing an example of individual identification information recorded in an information recording unit of the numerical control device according to the second embodiment; FIG. 11 is a flowchart showing the operation of a replacement detection function unit of each controller included in a numerically controlled machine tool according to the second embodiment; FIG. 12 is a block diagram showing a functional configuration of a replacement detection function unit implemented in each controller included in a numerically controlled machine tool according to the third embodiment; FIG. 13 is a block diagram showing a functional configuration of a replacement detection function unit implemented in each controller included in a numerically controlled machine tool according to the fourth embodiment;

[0011] An industrial control system according to an embodiment will be described in detail below with reference to the accompanying drawings.

[0012] First Embodiment Fig. 1 is a block diagram showing an example of the 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 uses a tool to remove material from a workpiece to achieve a desired shape, and executes machining operations based on a machining program.

[0013] 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 axes, X, Y, and Z. The spindle motor 17 and servo motors 16a, 16b, and 16c are rotated by receiving power from a power line (not shown). Position detectors 14a, 14b, 14c, and 14d that detect the rotation angle of each motor are attached to the servo motors 16a, 16b, and 16c and the spindle motor 17 for feedback control.

[0014] The motor rotation angles detected by the respective position detectors 14a, 14b, 14c, and 14d are transmitted to 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 via an optical communication cable 15.

[0015] The numerical control device 11 analyzes the machining program, calculates commands to 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).

[0016] In this specification, an industrial controller refers to a device that stores and executes programmed instructions and has the function of communicating with other devices. In the case of the numerically controlled machine tool 10, the industrial controllers include the numerical control device 11, motor drive devices 12a, 12b, and 12c, position detection devices 14a to 14d, and converter device 13. 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 also include controllers of peripheral devices including I / O (Input / Output) devices and display devices (not shown). 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.

[0017] 2 is a block diagram showing an example of the hardware configuration of a controller included in 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 work 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 all connected by a bus. Memory 81 is also used as a work area for processor 80.

[0018] The processor 80 includes a central processing unit (CPU) and the like. The memory 81 includes a random access memory (RAM), and the non-volatile memory 82 includes a hard disk drive (HDD), a solid state drive (SSD), and the like. However, the hardware configuration of the controller illustrated here is merely an example. For example, the processor 80 may be a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC) instead of a CPU, and the non-volatile memory 82 may be an electrically erasable programmable read-only memory (EEPROM®), flash memory, or the like. The non-volatile memory 82 may also be used as working memory 81. Furthermore, the communication interface 83 may be implemented as a function within the CPU, or may be implemented as hardware with a CPU or ASIC dedicated to communication. Furthermore, a single controller may have multiple communication interfaces 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 wireless communication I / Fs include 5G (5th Generation Mobile Networks), Wi-Fi (registered trademark) (Wireless Fidelity), Bluetooth (registered trademark), etc.

[0019] 3 is a block diagram showing the system configuration of a numerically controlled machine tool 10 according to the first embodiment in terms of controller functions. In the numerically controlled machine tool 10, a numerical control device 11 serves as a higher-level controller and controls lower-level 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 motor drive device 12a, a Z-axis position command to motor drive device 12b, and a spindle rotation command to motor drive device 12c.

[0020] Motor drivers 12a, 12b, and 12c each have the role of controlling the motors connected to them in accordance with commands from numerical control device 11. Specifically, motor driver 12a outputs an X-axis motor current to servo motor 16a and a Y-axis motor current to servo motor 16b. Motor driver 12b outputs a Z-axis motor current to servo motor 16c. Motor driver 12c outputs a spindle motor current to spindle motor 17.

[0021] 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 motor drivers 12a, 12b, and 12c, which are higher-level controllers. 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.

[0022] Converter device 13 is connected to numerical control device 11 as a controller independent of motor drive devices 12a, 12b, and 12c. Converter device 13 outputs the power supply status to numerical control device 11. In this way, numerically controlled machine tool 10 is an industrial control system having a functional configuration with a three-tiered structure.

[0023] 4 is a block diagram showing an example of the functional configuration of a replacement detection function unit 1a implemented in each controller included in a 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 also in a new controller to be replaced. However, the components of the replacement detection function unit 1a, namely, the information recording unit 2 as a recording unit, the individual identification information transmitting unit 3 as a transmitting unit, the individual identification information comparing unit 4 as a comparing unit and determining unit, and the information updating unit 5 as an updating unit, are implemented in all controllers included in the numerically controlled machine tool 10, but the identifying unit 8 is implemented in one of all controllers included in the numerically controlled machine tool 10. As will be described in detail later, the identifying unit 8 has a function of identifying a replaced unit and is implemented in one controller functioning as an identifying device.

[0024] The information recording unit 2 is implemented in a non-volatile memory and stores the controller program, information necessary for executing processing such as program parameters related to processing, and individual identification information used by the replacement detection function unit 1a.

[0025] Fig. 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. Fig. 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 replacement detection of the numerical control device 11 and the motor drive device 12a will be described below.

[0026] 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 local device information recording unit 21 in which the serial number of the numerical control device 11 itself 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 local device information recording unit 21 in which the serial number of the motor drive device 12a itself is recorded. The serial number is uniquely defined for each product and is a number that can identify an individual controller. The serial number may be composed of numbers only or a combination of a character string and numbers, as long as it is information that can identify an individual controller. The local industrial controller (local controller) corresponds to the first industrial controller, and the controller connected to the local industrial controller (local 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.

[0027] The types of controllers included in the numerically controlled machine tool 10 and the connection configuration between each controller are predetermined by parameters used in the numerical control device 11. For example, the number and order of motor drive units 12a, 12b, and 12c connected to the numerical control device 11, and the number of position detection units 14a to 14d connected to each motor drive unit 12a, 12b, and 12c are predetermined. Typically, this configuration is not changed once the numerically controlled machine tool 10 is shipped. In this example, as shown in FIG. 5 , the individual identification information 20a in the information recording unit 2 of the numerical control device 11 includes the aforementioned own device information recording unit 21 and a connected device information recording unit 22 in which identification information of connected devices is recorded. The connected device information recording unit 22 includes the device names, serial numbers, and a replacement detection flag as a first flag for each of the three motor drive units 12a to 12c connected to the numerical control device 11. 6, like the individual identification information 20a, the individual identification information 20b in the information recording unit 2 of the motor drive device 12a includes a host device information recording unit 21 and a connected device information recording unit 22. The connected device information recording unit 22 includes the device names, serial numbers, and replacement detection flags for the numerical control device 11 as the connected upper controller and the two position detection devices 14a, 14b as lower controllers.

[0028] The connected device name may be in any format as long as the controller can uniquely recognize the device name. The replacement detection flag is set to 1 when the controller detects a replacement, and set to 0 otherwise. When a controller is replaced with a new device and connected to another controller, before startup, the serial number of the new device is recorded in the device information recording section 21 of the individual identification information recorded in the information recording section 2 of the new device. The connected device information recording section 22 of the individual identification information recorded in the information recording section 2 of the new device records the serial number of the previously connected controller immediately before the replacement, in other words, a replacement detection flag set to 0. If the new device is unused, the connected device information recording section 22 is empty and remains in its initial state. However, the replacement detection flag may be forcibly set to 0 externally before replacement. For example, the information in the information recording section 2 may be rewritten using dedicated software, or a replacement detection flag rewrite command may be sent from an input device such as a keyboard (not shown) to overwrite the replacement detection flag.

[0029] 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, which is recorded in the local device information recording unit 21 of the information recording unit 2, to the other controller. The individual identification information transmission unit 3 of the controller equipped with the identification unit 8 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, retrieves 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 communication between controllers, the controller that receives the serial number can determine from which connected device the serial number was received. 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 this fact. 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 replacement 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.

[0030] 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 the controllers are connected, each controller performs replacement detection. At the beginning of replacement detection, all controllers on the network notify their own serial numbers to the connected controllers. Here, an example will be described in which each controller transmits its serial number in a predetermined order.

[0031] 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 returns to step S1.

[0032] 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.

[0033] When all controllers have completed sending and receiving 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).

[0034] 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.

[0035] 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.

[0036] The information updating 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 connected device information recording unit 22 of the individual identification information in the information recording unit 2, updates the replacement detection flag to 1 (step S7), and then completes the replacement detection. However, replacement detection may be performed every time each controller is started, or may be performed periodically, such as every month or every six months, or may be performed by an operator's operation input.

[0037] The identification of the replaced unit performed by the identification unit 8 will now be described. In the numerically controlled machine tool 10 shown in FIG. 1 , assume that the motor drive unit 12a is the replaced unit. Since the motor drive unit 12a is the replaced unit, the serial number of the replaced device is recorded in the device information recording section 21 of the individual identification information 20b of the information recording section 2 of the motor drive unit 12a. Furthermore, 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, resulting in an initial state. Meanwhile, the serial number of the device before the replacement, as the motor drive unit 12a, is recorded in the field for the motor drive unit 12a in 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. For this reason, in the comparison process in the numerical control device 11, the serial number recorded in the column for motor drive device 12a in the connection device information recording unit 22 does not match the serial number received from motor drive device 12a. Also, in the comparison process in motor drive device 12a, the serial numbers recorded in the columns for numerical control device 11, position detection device 14a, and position detection device 14b in the connection device information recording unit 22 of the information recording unit 2 of motor drive device 12a do not match the serial numbers received from the numerical control device 11, position detection device 14a, and position detection device 14b. Although a description of the operation of position detection device 14a and position detection device 14b will be omitted, in this case, the numerical control device 11, position detection device 14a, and position detection device 14b detect that the motor drive device 12a has been replaced, and the motor drive device 12a detects that the numerical control device 11, position detection device 14a, and position detection device 14b have become the new connection destinations.

[0038] The individual identification information recorded in the information recording unit 2 of all controllers that make up the numerically controlled machine tool 10 is transmitted to one of the multiple controllers that make up the numerically controlled machine tool 10 or to an external computer.

[0039] 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 for the replaced unit will be referred to as the "identifying device." When the identifying device is configured from one of the multiple controllers, the controller that becomes the identifying device includes the identification unit 8 shown in FIG. 4.

[0040] 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 identification device. The identification device may be the numerical control device 11, which is the highest-level controller, or another controller. Alternatively, the identification device may be an external computer connected to the numerical control device 11 directly or via a network, or a computer in the cloud.

[0041] The identification unit 8 of the identifying 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 identifying device causes the information update unit 5 to update the content of the individual identification information in the information recording unit 2 based on the determination result. The identification unit 8 of the identifying device also transmits the determination result to all controllers. The information update unit 5 of each controller that has received the determination result updates the content of the individual identification information in the information recording unit 2 based on the determination result. In other words, the controller that made the erroneous determination of the replaced equipment corrects the content of the individual identification information in the information recording unit 2 based on the determination result of the majority vote. Note that the determination result of the identifying device may be transmitted only to some of the controllers that made the erroneous determination.

[0042] 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 is replaced out of the nine controllers shown in Fig. 3. It is also assumed that, 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.

[0043] For example, in the numerically controlled machine tool 10 shown in Fig. 1, after the motor drive unit 12a is replaced, information about the controller of the other system that was previously connected is recorded in 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. Therefore, in the motor drive unit 12a newly incorporated into the numerically controlled machine tool 10, it is detected in the replacement device detection process at startup shown in Fig. 7 that the controller of the other system that was previously connected has been replaced.

[0044] On the other hand, in each controller other than the motor drive unit 12a, the serial number transmitted from the motor drive unit 12a, the serial number recorded in the motor drive unit 12a column of the connection device information recording unit 22 possessed by the controller itself, and the serial number received from the motor drive unit 12a newly incorporated into the numerically controlled machine tool 10 do not match, and it is detected that the motor drive unit 12a has been replaced.

[0045] The identifying 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 identifying unit 8 of the identifying device refers to the individual identification information received from each controller.

[0046] At this time, the identifying unit 8 of the identifying device refers to the individual identification information received from motor drive device 12a and recognizes that the connection destination has been changed to the controller belonging to numerically controlled machine tool 10. Specifically, the identifying unit 8 of the identifying device recognizes that the connection destination of motor drive device 12a has been changed to the controller belonging to numerically controlled machine tool 10 because the exchange detection flags of the records corresponding to numerical control device 11, position detection device 14a, and position detection device 14b shown in Fig. 3 are set to 1 in the individual identification information.

[0047] Next, the identifying unit 8 of the identifying device refers to the individual identification information received from the eight controllers other than the motor driving device 12a and recognizes that the motor driving device 12a has been replaced. Specifically, the identifying unit 8 of the identifying device recognizes that the motor driving device 12a has been replaced because the replacement detection flag of the record corresponding to the motor driving device 12a newly installed in the numerically controlled machine tool 10 is set to 1, among the individual identification information.

[0048] The identification unit 8 of the identification device finally determines that the motor driving device 12a has been replaced based on the recognition results based on the individual identification information received from the motor driving device 12a and the recognition results based on the individual identification information received from the eight controllers other than the motor driving device 12a.

[0049] 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.

[0050] In an industrial control system consisting of only one pair of controllers, it is difficult to determine which controller has been replaced. However, in the first embodiment, all controllers record the serial numbers of the controllers connected to them. Therefore, for example, if only one controller is replaced in a system consisting of three controllers, the other two controllers record each other's serial numbers, but the newly replaced controller does not retain any information about the other two controllers, making it 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 each other's serial numbers, but the two replaced controllers do not retain any information about the other three controllers, making it possible to identify which controller has been replaced by majority vote.

[0051] Note that, when the numerically controlled machine tool 10 is started, for example, controller C, which is not directly connected to controller A, may receive the serial number associated with controller A via controller B, which is directly connected to controllers A and C, and record a result corresponding to the comparison result in the individual identification information of the information recording unit 2. This avoids the difficulty of determining the replaced controller by majority vote due to a small number of directly connected controllers. For example, if the position detection devices 14a-14c connected to motor drivers 12a and 12b also record the serial number of the numerical control device 11, and motor driver 12b also records the serial number of motor driver 12a, when motor driver 12a is replaced, while many controllers will record that motor driver 12a has been replaced, only motor driver 12a will record that another controller has become the new connection destination. This allows controller replacement determination to be made by majority vote even when there are only a small number of directly connected controllers.

[0052] As described above, according to the first embodiment, the identifying device identifies the replaced controller based on the mutual judgment results of mutual communication between multiple controllers, so that the replacement of a controller can be detected with high accuracy throughout the system, and the reliability of the replacement detection is high. Furthermore, even when a higher-level controller is replaced, the replaced controller can be identified with high accuracy. Even when 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 that 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 the second embodiment.

[0053] Embodiment 2 The controller to which the replacement detection function of embodiment 2 is applied is the controller constituting the same numerically controlled machine tool 10 as in embodiment 1. Hereinafter, embodiment 2 will be described, focusing on the differences from embodiment 1.

[0054] 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 exchange detection function unit 1b of embodiment 2, a date and time measurement unit 6 is added, and information update unit 5b records individual identification information including date and time information measured by date and time measurement unit 6 in information recording unit 2.

[0055] FIG. 9 is a diagram illustrating 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 a connected controller is replaced, the serial number is overwritten in the connection device information recording unit 22 of the information recording unit 2. However, in the second embodiment, when a 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 a connected controller is replaced, the serial number of the previously connected controller and the serial number of the currently replaced controller are recorded in the connection device information recording unit 22 of the information recording unit 2. Also, in the second embodiment, the date and time when the controller replacement is detected are recorded in the connection device information recording unit 22 of the information recording unit 2. FIG. 9 illustrates a case where the motor drive unit 12a is replaced. With regard to the motor drive unit 12a, the serial number and the detection date and time of the previously connected controller and the serial number and the detection date and time of the currently replaced controller are recorded in the connection device information recording unit 22 of the information recording unit 2 of the numerical control device 11.

[0056] FIG. 10 is a flowchart showing the operation of the replacement detection function unit 1b of each controller included in the numerically controlled machine tool 10 according to the second embodiment. The operation content from step S1 to step S5 is the same as that of the first embodiment, and therefore a repeated description will be omitted. When all controllers have completed sending and receiving their serial numbers (step S1: Yes), the individual identification information comparison unit 4 of each controller compares the received serial numbers with the serial numbers recorded in the connected device information recording unit 22 of the information recording unit 2 for all controllers whose serial numbers have been received, and determines whether there is a newly connected device that is different from any controller connected at any time in the past (step S6b). When there is no newly connected device (step S6b: No), the individual identification information comparison unit 4 of each controller determines that none of the connected controllers have been replaced, and completes replacement detection. When there is a newly connected device (step S6b: Yes), the individual identification information comparison unit 4 of each controller determines that the newly connected device among the connected controllers has been replaced, and notifies the information update unit 5 of this fact. 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 replacement detection flag to 1, records the current date and time when the replacement was detected as date and time information (step S7b), and then completes the replacement detection.

[0057] 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 references 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 past date and time information have not been replaced, and that the other three controllers have been replaced.

[0058] In this way, in the second embodiment, the date and time information is recorded in conjunction with the serial number. Therefore, 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 determine that the majority of the controllers have been replaced and identify the replaced controller based on this.

[0059] According to the second embodiment, the individual identification information of previously connected controllers and the date and time of replacement are recorded, so that even if the majority of controllers have been replaced, it becomes possible to identify the replaced controller more easily and with higher accuracy.

[0060] Embodiment 3 The controller to which the replacement detection function of embodiment 3 is applied is the controller constituting the same numerically controlled machine tool 10 as in embodiment 1. Hereinafter, embodiment 3 will be described, focusing on the differences from embodiment 1.

[0061] 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 exchange detection function unit 1c of embodiment 3, a control mode receiving unit 7 is added, and information updating unit 5c performs an update operation in information recording unit 2 based on the information received by control mode receiving unit 7 and the comparison result by individual identification information comparing unit 4.

[0062] 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, or 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.

[0063] 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 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, a connected device information recording unit 22 in which the serial number and replacement detection flag of the connected controller are recorded is managed for each control mode. A first table 22a, which is the connected device information recording unit 22, records the serial numbers and replacement detection flags of the motor drivers 12a and 12b, which are controllers connected in the first control mode. A second table 22b, which is the connected device information recording unit 22, records the serial numbers and replacement detection flags of the motor drivers 12a, 12b, and 12c, which are controllers connected in the second control mode.

[0064] When the control mode receiving unit 7 notifies the replacement detection unit 1c that the first control mode is selected, the replacement detection unit 1c refers to the first table 22a to determine whether replacement should be detected. On the other hand, when the control mode receiving unit 7 notifies the replacement detection unit 1c that the second control mode is selected, the replacement detection unit 1c refers to the second table 22b to perform replacement detection.

[0065] Thus, according to the third embodiment, when the connected controller changes depending on the control mode, the individual identification information of the connected controller is managed separately depending on the control mode, so that accurate replacement detection is possible even when the connected controller changes depending on the control mode.

[0066] Embodiment 4 The controller to which the replacement detection function of embodiment 4 is applied is the controller constituting the same numerically controlled machine tool 10 as in embodiment 1. Hereinafter, embodiment 4 will be described, focusing on the differences from embodiment 1.

[0067] 13 is a block diagram showing the functional configuration of a replacement detection function unit 1d implemented in each controller included in a numerically controlled machine tool 10 according to the fourth embodiment. The replacement detection function unit 1d of the fourth embodiment has an information update unit 5d that receives a genuine product notification flag as a second flag. The other configuration is the same as that of the first embodiment, and therefore a duplicated description will be omitted.

[0068] When an industrial controller fails, it may be replaced after repair. In such cases, no problems arise if the controller is replaced with a new one or one that has been repaired using authorized procedures. However, problems may arise if the controller is replaced with one that has been repaired using unauthorized means. Therefore, when the controller is replaced with an authorized controller, an authorized product notification flag 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, notifying the information update unit 5d of the replaced controller that the replacement is authorized. The information update unit 5d of the replaced controller associates the serial number of the newly connected controller with the authorized product notification flag and records them in the information recording unit 2.

[0069] Regarding transmission of the genuine product notification flag, for example, the genuine product notification flag may be transmitted by inputting a specific password, or the genuine product notification flag may be transmitted via a network such as the Internet when authenticated via a server managed by the manufacturer such as a cloud or edge. Also, the genuine product notification flag may be transmitted during the first communication after the replacement, or an operation to notify the genuine product notification flag may be performed at any timing after the replacement.

[0070] FIG. 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, a 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. However, since the genuine product notification flag has been received, the non-genuine product flag is 0. On the other hand, since the motor drive unit 12c has not received the genuine product notification flag, the non-genuine product flag is recorded as 1, indicating that the controller was replaced without going through legitimate means.

[0071] 14, the serial numbers, replacement detection flags, and non-genuine product flags of the position detection devices 14a, 14b, ... are recorded in the connection device information recording unit 22 of the information recording unit 2 of the numerical control device 11. In the fourth embodiment, as described in the first embodiment, the serial numbers of the position detection devices 14a, 14b, 14c, and 14d that are not directly connected to the numerical control device 11 are transmitted from the position detection devices 14a, 14b, 14c, and 14d via the motor driving devices 12a, 12b, and 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 detection devices 14a, 14b, 14c, and 14d via the motor driving devices 12a, 12b, and 12c.

[0072] In the fourth embodiment, it is possible to detect an unauthorized controller replacement, 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.

[0073] As described above, according to the fourth embodiment, it is possible to determine whether the replaced controller is genuine or non-genuine.

[0074] Fifth Embodiment Fig. 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.

[0075] 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.

[0076] In the first embodiment, all the controllers are connected using the same communication method, but in the fifth embodiment, the controllers are connected using different communication methods. 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 by wireless communication. The PLC device 63 of the transport device 62 is connected to the PLC device 70 by dedicated PLC communication.

[0077] The numerical control device 11a and the PLC device 63 cannot communicate directly because they use different communication methods, but if the PLC device 70, which is a higher-level controller, acts as a relay, individual identification information can be transmitted and received between the numerical control device 11a and the PLC device 63. For example, by recording information on all controllers (numerical control devices 11a and 11b, robot control device 61, PLC devices 63 and 70) in the information recording unit 2 of the PLC device 70 and transmitting the individual identification information of all controllers in the individual identification information transmitting unit 3 via multiple communication interfaces of the PLC device 70, it becomes possible to share individual identification information even between controllers connected using different communication methods.

[0078] Furthermore, in the first embodiment, a serial number that is uniquely assigned to 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.

[0079] FIG. 16 is a diagram illustrating an example of the individual identification information 20e used in the production system 100 according to the fifth embodiment. The individual identification information 20e includes the name, type, total operating time, total number of alarms, and non-genuine product flag for the device itself (its own device) 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 operating. 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.

[0080] Other information for identifying a controller may be a combination of information such as the time of last communication, the total number of processed parts, the time of the previous failure, etc. Since the individual identification information 20e is used to determine whether a controller connected in the production system 100 has been replaced, it does not have to be completely unique information like a serial number, as long as it is information that is likely to enable detection that the controller before replacement and the controller after replacement are different individuals.

[0081] As described above, according to the fifth embodiment, individual identification information is communicated between all of the controllers via a host controller that is connected to all of the controllers via a plurality of different communication interfaces, so that controller replacement can be detected even in production system 100 in which controllers having different communication methods are connected. Also, by combining multiple pieces of information such as the total operating time, the total number of alarms that have occurred, the time of the last communication, the total number of machined parts, and the time of the previous failure, it is determined whether the controller before and the controller 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 replaced correctly.

[0082] 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 embodiments may be combined with each other, and some of the configurations may be omitted or modified within the scope of the gist of the present disclosure.

[0083] 1a, 1b, 1c, 1d Replacement 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

1. An industrial control system in which a plurality of industrial controllers having individual identification information are connected and function. Each of the plurality of industrial controllers includes a recording unit that records first individual identification information including its own individual identification information and second individual identification information including the individual identification information of a second industrial controller that is another industrial controller connected to the first industrial controller, a transmission unit that transmits the first individual identification information to the second industrial controller, a comparison unit that compares the second individual identification information recorded in the recording unit with the received second individual identification information when receiving the second individual identification information from the second industrial controller, and a determination unit that determines that the second industrial controller has been replaced when the comparison results are different. An industrial control system characterized by comprising the above.

2. The industrial control system according to claim 1, further comprising an update unit that updates the second individual identification information recorded in the recording unit when the comparison results are different.

3. The industrial control system according to claim 1 or 2, characterized in that there are three or more of the industrial controllers, and a specifying device that specifies an industrial controller replaced using the second individual identification information recorded in the recording units of the plurality of industrial controllers is provided.

4. The industrial control system according to any one of claims 1 to 3, characterized in that 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.

5. The industrial control system according to any one of claims 1 to 4, characterized in that the individual identification information is a serial number.

6. The industrial control system according to any one of claims 1 to 5, characterized in that the second individual identification information includes a first flag indicating the presence or absence of replacement of the second industrial controller.

7. The industrial control system according to any one of claims 1 to 6, characterized in that the second individual identification information includes date and time information indicating the date and time of replacement of the second industrial controller.

8. The industrial control system according to any one of claims 1 to 7, characterized in that the second individual identification information includes a second flag indicating whether it is a genuine product or a non-genuine product.

9. The industrial control system according to any one of claims 1 to 8, characterized in that the second individual identification information includes the individual identification information of the second industrial controller connected in the first control mode and the individual identification information of the second industrial controller connected in the second control mode.

10. The industrial control system according to any one of claims 1 to 3, characterized in that the individual identification information includes at least two of the energization time, the number of alarm occurrences, the time of the last communication, the total number of processed parts, and the time of the last failure occurrence.

11. The industrial control system according to any one of claims 1 to 10, characterized in that each of the industrial controllers includes a numerical control device that is a higher-level controller, a motor drive device that 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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