Control system and control method

Abstract

A control system for controlling each of a plurality of control objects by means of a physical machine having a plurality of virtual machines comprises: a first virtual machine that is at least one from among a plurality of virtual machines, the first virtual machine having a first communication unit that communicates with each of the plurality of control objects, receives data used in controlling the control objects, and transmits a control instruction to the control objects, and having a distribution unit that distributes the data received from the control objects to another virtual machine; and a second virtual machine that is different from the first virtual machine from among the plurality of virtual machines, the second virtual machine having a computation processing unit that issues a control instruction to the control objects on the basis of an analysis result obtained by analyzing the data.

Description

Control system and control method

[0001] This application claims priority to Japanese Patent Application No. 2023-138039, filed on August 28, 2023, the contents of which are incorporated herein by reference.

[0002] 6 is used as a system for controlling and monitoring a plant such as a power plant. The plant system 9 includes a control device 92, a control system 93, and a host device 94.

[0003] The control device 92 outputs a control signal to the control target 90 based on data acquired from the control target 90 and predetermined control logic. The control device 92 also outputs a control signal to the control target 90 based on an instruction received from the control system 93.

[0004] The control system 93 is composed of multiple physical machines 931. A different control application (APL) is implemented in each physical machine 931. The control APL is an application that performs control processing specific to each control target 90, and, for example, analyzes data acquired from the control device 92 and issues control instructions to the control device 92 based on the analysis results (calculation results). Each physical machine 931 is also implemented with a plant-side communication control function that receives data from the control target 90 via the control device 92 and transmits control instructions to the control device 92, a host-side communication control function that uploads the calculation results of the control APL to a host device 94, and a monitoring function that confirms whether the control system 93 is operating properly.

[0005] The host device 94 is communicably connected to the control system 93 via a network NW. The host device 94 is, for example, an analysis system that collects calculation results from the control system 93 and performs analysis.

[0006] 6, a conventional control system 93 requires one physical machine 931 for one function (control APL). Therefore, the more functions there are, the higher the cost required to build the control system 93 becomes, and the larger the installation space becomes.

[0007] In recent years, it has been considered to reduce the number of physical machines by constructing multiple virtual machines within one physical machine (see, for example, Patent Documents 1 and 2).

[0008] JP 2017-58734 A JP 2010-237742 A

[0009] However, conventional systems using virtual machines are constructed by transferring the functions implemented in each physical machine directly to each virtual machine. In other words, for example, if the physical machine 931 in the control system 93 described above is replaced with a virtual machine, similar functions such as a plant-side communication control function, an upper-level communication control function, and a monitoring function must also be implemented in each virtual machine in addition to the control APL specific to each physical machine 931. In this case, resources must be allocated to each similar function among multiple virtual machines, so it is necessary to either provide sufficiently large resources for the physical machines or limit the number of virtual machines to match the resources of the physical machines.

[0010] An object of the present disclosure is to provide a control system and a control method that can reduce costs and installation space by consolidating functions into one physical machine, and that can reduce resources used by the entire system.

[0011] According to one aspect of the present disclosure, a control system that controls multiple control objects using a physical machine having multiple virtual machines includes: a first virtual machine, which is at least one of the multiple virtual machines, and which has a first communication unit that communicates with each of the multiple control objects, receives data used to control the control objects, and sends control instructions to the control objects, and a distribution unit that distributes the data received from the control objects to other virtual machines; and a second virtual machine, which is one of the multiple virtual machines different from the first virtual machine, and which has an arithmetic processing unit that issues control instructions to the control objects based on analysis results of the data.

[0012] According to one aspect of the present disclosure, a control method using a control system in which a physical machine having a plurality of virtual machines controls each of a plurality of control objects includes the steps of a first virtual machine, which is at least one of the plurality of virtual machines, communicating with each of the plurality of control objects, receiving data used to control the control objects, and sending control instructions to the control objects; a step of the first virtual machine distributing the data received from the control objects to other virtual machines; and a step of a second virtual machine, different from the first virtual machine, among the plurality of virtual machines, analyzing the data and issuing control instructions to the control objects based on the analysis results.

[0013] According to the above aspect, functions can be consolidated into one physical machine, thereby reducing costs and installation space, and also reducing resources used by the entire system.

[0014] 1 is a diagram showing an overall configuration of a plant system according to a first embodiment; FIG. 2 is a block diagram showing a functional configuration of a control system according to the first embodiment; FIG. 3 is a first sequence diagram showing an example of processing of the control system according to the first embodiment; FIG. 4 is a second sequence diagram showing an example of processing of the control system according to the first embodiment; FIG. 5 is a diagram showing an example of a hardware configuration; FIG. 6 is a diagram showing the configuration of a plant system in a conventional technology;

[0015] First Embodiment Hereinafter, a first embodiment will be described in detail with reference to the drawings.

[0016] (Overall Configuration) Fig. 1 is a diagram showing the overall configuration of a plant system according to Embodiment 1. As shown in Fig. 1, the plant system 1 includes a control device 2, a control system 3, and a higher-level device 4.

[0017] The control device 2 acquires data used for controlling each of a plurality of control objects 10 provided in the plant, and outputs a control signal to the control object 10 based on the acquired data and a predetermined control logic. The control object 10 may be, for example, a machine such as a turbine or a compressor, or a component such as an actuator for a fuel valve or a bleed valve. The data used for controlling the control object 10 is data used to calculate specific control details for the control object 10, such as measurement values ​​of sensors (such as a thermometer, a pressure gauge, and an ammeter) provided on or around the control object 10. Furthermore, when the control device 2 receives a control instruction from the control system 3, it outputs a control signal corresponding to the control instruction to the control object 10.

[0018] The control system 3 includes at least one physical machine 31. The physical machine 31 is communicably connected to the control device 2 and the higher-level device 4 via a network NW.

[0019] The physical machine 31 has a plurality of virtual machines. The plurality of virtual machines include a first virtual machine 32 that executes processing common to each control target 10, and a second virtual machine 33 that executes control processing specific to each control target 10. The physical machine 31 may further include a third virtual machine 34 that executes processing common to each control target 10.

[0020] The first virtual machine 32 has a function of communicating with external devices (the control device 2 and the higher-level device 4) connected to the network NW. The second virtual machine 33 relays communication between the external devices and the other virtual machines 33 and 34. Therefore, the second virtual machine 33 and the third virtual machine do not need to have a function of communicating with external devices.

[0021] One second virtual machine 33 is provided for each control target 10. The second virtual machine 33 has a control application (APL) installed, analyzes data acquired from the control target 10, and issues control instructions to the control target 10 based on the analysis results (calculation results). This control instruction is sent to the control device 2 via the first virtual machine 32.

[0022] The third virtual machine 34 collects diagnostic data from each of the virtual machines 32 and 33 in the physical machine 31 and diagnoses the health of each of the virtual machines 32 and 33 .

[0023] The host device 4 is communicably connected to the control system 93 via the network NW. The host device 4 may be, for example, an analysis system that analyzes the operating state and operating efficiency of the plant based on the calculation results collected from the control system 3, or a management system that allows an operator to remotely operate each controlled object 10 by referring to the calculation results.

[0024] The plant system 1 may include a plurality of control devices 2, and each control device 2 may control one or a plurality of control targets 10. In this case, the control system 3 outputs a control instruction to one of the control devices 2 depending on the control target 10 to be controlled. The control system 3 may include a plurality of physical machines 31, and each physical machine 31 may output a control instruction to a different control device 2.

[0025] (Functional Configuration of Control System) FIG. 2 is a block diagram showing the functional configuration of the control system according to the first embodiment.

[0026] 2, the physical machine 31 is connected to the network NW via a physical network interface controller 35 (hereinafter also referred to as a "physical NIC"), which is a device for communicating with external devices (the control device 2 and the higher-level device 4) connected to the network NW.

[0027] Furthermore, on the processor of the physical machine 31, a first virtual switch 36 to which the physical NIC 35 is connected and a second virtual switch 37 to which each of the virtual machines 32, 33, and 34 is connected are generated.

[0028] A virtual network interface controller 32A (hereinafter also referred to as a "virtual NIC") of the first virtual machine 32 is connected to a first virtual switch 36. The first virtual machine 32 can communicate with the control device 2 and the higher-level device 4, which are external devices, via the first virtual switch 36.

[0029] Furthermore, the virtual NIC 32B of the first virtual machine 32 is connected to the second virtual switch 37. The first virtual machine 32 can communicate with the other virtual machines in the physical machine 31, namely, the second virtual machine 33 and the third virtual machine 34, via the second virtual switch 37.

[0030] The virtual NIC 33A of the second virtual machine 33 is connected to the second virtual switch 37. The second virtual machine 33 can communicate with the other virtual machines in the physical machine 31, namely, the first virtual machine 32 and the third virtual machine 34, via the second virtual switch 37.

[0031] The virtual NIC 34A of the third virtual machine 34 is connected to the second virtual switch 37. The third virtual machine 34 can communicate with the first virtual machine 32 and the second virtual machine 33, which are other virtual machines in the physical machine 31, via the second virtual switch 37.

[0032] (Functional configuration of first virtual machine) The first virtual machine 32 has a first communication unit 321, a second communication unit 322, a common data management unit 323, and a distribution unit 324 as functional units (containers, applications) that execute various processes.

[0033] The first communication unit 321 is included in the first network space NS1 configured by the first virtual switch 36.

[0034] The common data management unit 323 and the distribution unit 324 are included in a second network space NS2 configured by the second virtual switch 37. The functional units included in the second network space NS2 may be connected to the virtual NIC 32B and the first communication unit 321 via a virtual interface 32C that assigns a virtual MAC address to each functional unit and distributes data packets. The virtual interface 32C may be a function provided by a platform for building a virtual environment, such as macvlan.

[0035] The second communication unit 322 is included in a third network space NS3 that is different from the first network space NS1 and the second network space NS2. The third network space NS3 is communicably connected to the first network space NS1 and the second network space NS2 via virtual routers 32D and 32E.

[0036] The first communication unit 321 transmits and receives data between the control device 2 and the higher-level device 4. The first communication unit 321 communicates with each of the multiple control targets 10 via the control device 2, receives data used to control each control target 10, and transmits control instructions to each control target 10.

[0037] The second communication unit 322 transmits data collected from each control target 10 , calculation results of each second virtual machine 33 , control instructions, and the like to the higher-level device 4 .

[0038] The common data management unit 323 manages data commonly used among the virtual machines 32, 33, and 34. For example, the common data management unit 323 stores and deletes data received by the first communication unit 321 from each control target 10, calculation results received from the other virtual machines 33 and 34, control instructions, and the like.

[0039] The distribution unit 324 distributes the data stored in the common data management unit 323 to the distribution destinations corresponding to each data. For example, the distribution unit 324 distributes data acquired from the control target 10 to the second virtual machine 33 corresponding to the control target 10 using technology such as AMQP (Advanced Message Queuing Protocol). The distribution unit 324 also distributes (transmits) control instructions and calculation results of the second virtual machine 33 to the control device 2 and the higher-level device 4 via the first communication unit 321 and the second communication unit 322.

[0040] (Functional Configuration of Second Virtual Machine) The second virtual machine 33 has a processing unit 331 as a functional unit (container, application) that executes various processes. The functional units included in the second network space NS2 may be connected to the virtual NIC 33A via a virtual interface 33B that assigns a virtual MAC address to each functional unit and distributes data packets. The virtual interface 33B may be a function provided by a platform for building a virtual environment, such as macvlan.

[0041] The calculation processing unit 331 uses the control APL to issue a control instruction to the control target 10 based on the analysis result (calculation result) obtained by analyzing the data acquired from the control target 10. This control instruction is sent to the first virtual machine 32 via the second virtual switch 37.

[0042] (Functional configuration of third virtual machine) The third virtual machine 34 has a diagnostic data collection unit 341, a diagnosis unit 342, a diagnostic result DB 343, and a log collection unit 344 as functional units (containers, applications) that execute various processes.

[0043] The diagnostic data collection unit 341, the diagnostic unit 342, and the diagnostic result DB 343 are included in a second network space NS2 configured by the second virtual switch 37. The functional units included in the second network space NS2 may be connected to the virtual NIC 34A via a virtual interface 34B that assigns a virtual MAC address to each functional unit and distributes data packets. The virtual interface 34B may be a function provided by a platform for building a virtual environment, such as macvlan.

[0044] The log collection unit 344 is included in a fourth network space NS4 that is different from the second network space NS2. The fourth network space NS4 is communicably connected to the second network space NS2 via a virtual router 34C.

[0045] The diagnostic data collection unit 341 collects diagnostic data used for diagnosing the health of the first virtual machine 32 and the second virtual machine 33. The diagnostic data includes, for example, the usage rate of the storage area allocated to each virtual machine, history information of various processes, and the like.

[0046] Based on the diagnostic data, the diagnostic unit 342 diagnoses the health of each of the first virtual machine 32 and the second virtual machine 33. For example, the diagnostic unit 342 diagnoses whether the usage rate of the storage area of ​​each virtual machine exceeds a specified value, whether each virtual machine has stopped functioning, and so on.

[0047] The diagnosis result DB 343 stores the diagnosis results from the diagnosis unit 342 .

[0048] The log collection unit 344 collects logs such as data acquired by each virtual machine and calculation results.

[0049] (Processing Example 1 of Control System) Fig. 3 is a first sequence diagram showing an example of processing of the control system according to the first embodiment. Hereinafter, the flow of processing in which the control system 3 controls the control target 10 will be described with reference to Fig. 3 .

[0050] First, the control target 10 transmits data such as sensor measurement values ​​to the control device 2 at predetermined intervals (step S100). The control device 2 then transmits the data received from the control target 10 to the control system 3 (step S101).

[0051] When the first communication unit 321 of the first virtual machine 32 receives the data of the control target 10, the shared data management unit 323 records the received data in a predetermined storage area (step S102).

[0052] Next, the distribution unit 324 distributes the data of the control target 10 to the second virtual machine 33 corresponding to this control target 10 (step S103). Note that the same data (such as measurement values ​​from the same sensor) may be used to control each of multiple control targets 10. In this case, multiple second virtual machines 33 corresponding to each control target 10 may be set in advance as destinations for this data. In this case, the distribution unit 324 distributes this data to each of the multiple second virtual machines 33. At this time, the distribution unit 324 may also distribute the data to the third virtual machine 34 for log recording. In this case, the log collection unit 344 of the third virtual machine 34 records the distributed data in a predetermined storage area (step S104).

[0053] The processing unit 331 of the second virtual machine 33 analyzes the delivered data of the control target 10 (step S105), and issues a control instruction to the control target 10 based on the analysis result (step S106). This control instruction is first sent to the first virtual machine 32.

[0054] The shared data management unit 323 of the first virtual machine 32 records the control instruction received from the second virtual machine 33 in a predetermined storage area (step S107).

[0055] The distribution unit 324 distributes (transmits) the control instruction received from the second virtual machine 33 to the corresponding control target 10 via the first communication unit 321 (step S108). At this time, the distribution unit 324 may also distribute data for log recording to the third virtual machine 34. In this case, the log collection unit 344 of the third virtual machine 34 then records the distributed data in a predetermined storage area (step S109).

[0056] Furthermore, the control device 2 generates a control signal based on the control instruction received from the control system 3 and transmits the generated control signal to the controlled object 10 (step S110). The controlled object 10 performs an operation according to the control signal received from the control device 2.

[0057] (Processing Example 2 of Control System) Fig. 4 is a second sequence diagram showing an example of processing of the control system according to the first embodiment. Hereinafter, the flow of self-diagnosis processing of the control system 3 will be described with reference to Fig. 4 .

[0058] First, the first virtual machine 32 and the second virtual machine 33 each transmit diagnostic data for health diagnosis to the third virtual machine 34 (step S200).

[0059] The diagnostic data collection unit 341 of the third virtual machine 34 collects diagnostic data from each of the virtual machines 32 and 33. The diagnostic unit 342 of the third virtual machine 34 diagnoses the health of each of the virtual machines 32 and 33 based on the diagnostic data collected from each of the virtual machines 32 and 33 (step S201), and records the diagnostic results in the diagnostic result DB 343 (step S202).

[0060] The diagnosis unit 342 may transmit the diagnosis result to the higher-level device 4 at predetermined intervals or when requested by the higher-level device 4 (e.g., a monitoring device that monitors a plant). At this time, the diagnosis unit 342 transmits the diagnosis result to the first virtual machine 32 (Step S203). Then, the second communication unit 322 of the first virtual machine 32 transmits the diagnosis result received from the third virtual machine 34 to the higher-level device 4 (Step S204).

[0061] (Operations and Effects) As described above, the control system 3 according to this embodiment is a system for controlling multiple control targets 10 using a physical machine 31 having multiple virtual machines, and includes a first virtual machine 32 that is at least one of the multiple virtual machines, and a second virtual machine 33 that is a virtual machine different from the first virtual machine 32. The first virtual machine 32 includes a first communication unit 321 that receives data used to control the control target 10 and transmits control instructions to the control target 10, and a distribution unit 324 that distributes data received from the control target 10 to other virtual machines. The second virtual machine 33 includes a calculation processing unit 331 that issues control instructions to the control target 10 based on analysis results of data received from the control target 10.

[0062] Conventional control systems require a physical machine to be prepared for each control target 10. However, the control system 3 according to this embodiment, configured as described above, can control multiple control targets 10 using a single physical machine 31 that has multiple virtual machines. This reduces the number of physical machines, thereby reducing the cost required to build the control system 3 and the installation space for the control system 3.

[0063] As described above, conventional systems using virtual machines are constructed by transferring the functions implemented in each physical machine directly to each virtual machine. Therefore, each virtual machine must individually receive data and send control instructions to and from the control target (control device). In contrast, in the control system 3 according to the present embodiment, the communication function with the control device 2 is extracted as a function common to all virtual machines and consolidated only in the first virtual machine 32. This eliminates the need for the second virtual machine 33 to have a common function (i.e., a communication function) that overlaps with the first virtual machine 32, thereby reducing the resources required for the common function. This allows the control system 3 to increase the number of second virtual machines 33 (i.e., the number of control APLs) operating in parallel while suppressing an increase in the resources required for the entire system. In other words, the number of second virtual machines 33 (control APLs) that can operate on one physical machine 31 can be increased, thereby minimizing the number of physical machines 31. Furthermore, the second virtual machine 33 can secure sufficient resources for the arithmetic processing unit 331 (control APL) by excluding the communication function with the control device 2, thereby improving the processing speed of the control APL's startup, shutdown, calculation, and other operations.

[0064] Furthermore, each of the plurality of second virtual machines 33 is associated with each of the plurality of control targets 10 , and the distribution unit 324 of the first virtual machine 32 distributes the data of the control targets 10 to the corresponding second virtual machine 33 .

[0065] Each second virtual machine 33 may execute different processes using the same data when controlling each control target 10. In this embodiment, as described above, the first virtual machine 32 collectively receives data from the control device 2 and distributes the received data to the corresponding second virtual machines 33. This reduces the number of communications between the control system 3 and the control device 2. This makes it possible to improve the communication speed of the entire plant system 1.

[0066] The control system 3 further includes a third virtual machine 34, which is at least one of the multiple virtual machines and has a diagnostic unit 342 that diagnoses the operation of the first virtual machine 32 and the second virtual machine 33 based on diagnostic data collected from each of the first virtual machine 32 and the second virtual machine 33.

[0067] In conventional technology, for example, if an abnormality occurs in the control APL of a physical machine, the abnormality could cause the entire physical machine to stop operating. Furthermore, as described above, conventional systems using virtual machines are constructed by transferring functions implemented in each physical machine directly to each virtual machine. Therefore, if an abnormality occurs in the control APL of a virtual machine, the operation of the entire virtual machine could stop. In such cases, conventional technology could prevent operators and others from quickly recognizing the occurrence of an abnormality. In contrast, in the control system 3 of this embodiment, an independent third virtual machine 34 diagnoses the health of the other virtual machines 32 and 33. In this way, even if, for example, an abnormality occurs in the control APL of a second virtual machine 33 and the operation of the second virtual machine stops, the diagnosis unit 342 of the third virtual machine 34 can detect the abnormality (operational stop) of the second virtual machine 33.

[0068] The first virtual machine 32 further includes a second communication unit 322 that acquires the status signal of the control target 10 and the control instruction calculated in the second virtual machine and transmits them to the higher-level device 4 .

[0069] This allows the control system 3 to transmit the calculation results of each control APL to a higher-level device 4 such as a plant analysis system or a remote control terminal. The second communication unit 322 of the first virtual machine 32 may also transmit the diagnosis result of the diagnosis unit 342 of the third virtual machine 34 to the higher-level device 4. This allows an operator or the like to quickly recognize that an abnormality has occurred in the control system 3.

[0070] Other Embodiments Although one embodiment has been described in detail above with reference to the drawings, the specific configuration is not limited to the above, and various design modifications are possible. That is, in other embodiments, the order of the above-described processes may be changed as appropriate. Furthermore, some processes may be executed in parallel.

[0071] For example, in the above embodiment, the third virtual machine 34 has the diagnostic function (the diagnostic data collector 341, the diagnostic unit 342, and the diagnostic result DB 343) for the health of the control system 3. However, this is not limiting. In other embodiments, the first virtual machine 32 may have the diagnostic function instead of or in addition to the third virtual machine 34. If both the first virtual machine 32 and the third virtual machine 34 have these diagnostic functions, a cross-check of the health of these virtual machines 32 and 34 is performed. Furthermore, even if an abnormality occurs in the third virtual machine 34, the first virtual machine 32 can detect this abnormality. This improves the reliability of the diagnostic results for the health of the control system 3.

[0072] <Hardware Configuration> FIG. 5 is a diagram illustrating an example of a hardware configuration.

[0073] The computer 900 includes a processor 901 , a main memory device 902 , an auxiliary memory device 903 , and an interface 904 .

[0074] The physical machine 31 of the control system 3 described above is implemented in a computer 900. The operations of each of the above-described processing units are stored in the form of a program in an auxiliary storage device 903. The processor 901 reads the program from the auxiliary storage device 903, loads it into the main storage device 902, and executes the above-described processing in accordance with the program. The processor 901 also allocates storage areas in the main storage device 902 corresponding to each of the above-described storage units in accordance with the program.

[0075] The program may be for realizing some of the functions to be performed by the computer 900. For example, the program may be combined with other programs already stored in the auxiliary storage device 903 or other programs implemented in other devices to perform the functions. In other embodiments, the computer 900 may include a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to or instead of the above configuration. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, some or all of the functions realized by the processor 901 may be realized by the integrated circuit.

[0076] Examples of the auxiliary storage device 903 include a hard disk drive (HDD), a solid state drive (SSD), a magnetic disk, a magneto-optical disk, a compact disc read-only memory (CD-ROM), a digital versatile disc read-only memory (DVD-ROM), and a semiconductor memory. The auxiliary storage device 903 may be an internal medium directly connected to the bus of the computer 900, or an external storage device 910 connected to the computer 900 via the interface 904 or a communication line. Furthermore, if this program is distributed to the computer 900 via a communication line, the computer 900 that receives the program may load the program into the main storage device 902 and execute the above-described processing. In at least one embodiment, the auxiliary storage device 903 is a non-transitory tangible storage medium.

[0077] The program may also be a program for realizing some of the above-described functions. Furthermore, the program may be a so-called differential file (differential program) that realizes the above-described functions in combination with another program already stored in the auxiliary storage device 903.

[0078] <Additional Notes> The control system and control method described in the above-described embodiment can be understood, for example, as follows.

[0079] (1) According to a first aspect, the control system 3 is a control system 3 that controls each of a plurality of control objects 10 using a physical machine 31 having a plurality of virtual machines, and includes: a first virtual machine 32, which is at least one of the plurality of virtual machines and has a first communication unit 321 that communicates with each of the plurality of control objects 10, receives data used to control the control objects 10, and transmits control instructions to the control objects 10, and a distribution unit 324 that distributes data received from the control objects 10 to other virtual machines; and a second virtual machine 33, which is a virtual machine among the plurality of virtual machines different from the first virtual machine 32 and has an arithmetic processing unit 331 that issues control instructions to the control objects 10 based on the analysis results of data analysis.

[0080] Conventional control systems require a physical machine to be prepared for each control target 10. However, the control system 3 according to this embodiment, configured as described above, can control multiple control targets 10 using a single physical machine 31 that has multiple virtual machines. This reduces the number of physical machines, thereby reducing the cost required to build the control system 3 and the installation space for the control system 3.

[0081] As described above, conventional systems using virtual machines are constructed by transferring the functions implemented in each physical machine directly to each virtual machine. Therefore, each virtual machine must individually receive data and send control instructions to and from the control target (control device). In contrast, in the control system 3 according to the present embodiment, the communication function with the control device 2 is extracted as a function common to all virtual machines and consolidated only in the first virtual machine 32. This eliminates the need for the second virtual machine 33 to have a common function (i.e., a communication function) that overlaps with the first virtual machine 32, thereby reducing the resources required for the common function. This allows the control system 3 to increase the number of second virtual machines 33 (i.e., the number of control APLs) operating in parallel while suppressing an increase in the resources required for the entire system. In other words, the number of second virtual machines 33 (control APLs) that can operate on one physical machine 31 can be increased, thereby minimizing the number of physical machines 31. Furthermore, the second virtual machine 33 can secure sufficient resources for the arithmetic processing unit 331 (control APL) by excluding the communication function with the control device 2, thereby improving the processing speed of the control APL's startup, shutdown, calculation, and other operations.

[0082] (2) According to the second aspect, in the control system 3 relating to the first aspect, each of the multiple second virtual machines 33 is associated with each of the multiple control targets 10, and the distribution unit 324 of the first virtual machine 32 distributes data of the control targets 10 to the corresponding second virtual machine 33.

[0083] Each second virtual machine 33 may execute different processes using the same data when controlling each control target 10. In this embodiment, as described above, the first virtual machine 32 collectively receives data from the control device 2 and distributes the received data to the corresponding second virtual machines 33. This reduces the number of communications between the control system 3 and the control device 2. This makes it possible to improve the communication speed of the entire plant system 1.

[0084] (3) According to the third aspect, the control system 3 relating to the first or second aspect further includes a third virtual machine 34, which is at least one of the multiple virtual machines and has a diagnostic unit 342 that diagnoses the operation of the first virtual machine 32 and the second virtual machine 33 based on diagnostic data collected from each of the first virtual machine 32 and the second virtual machine 33.

[0085] In conventional technology, for example, if an abnormality occurs in the control APL of a physical machine, the abnormality could cause the entire physical machine to stop operating. Furthermore, as described above, conventional systems using virtual machines are constructed by transferring functions implemented in each physical machine directly to each virtual machine. Therefore, if an abnormality occurs in the control APL of a virtual machine, the operation of the entire virtual machine could stop. In such cases, conventional technology could prevent operators and others from quickly recognizing the occurrence of an abnormality. In contrast, in the control system 3 of this embodiment, an independent third virtual machine 34 diagnoses the health of the other virtual machines 32 and 33. In this way, even if, for example, an abnormality occurs in the control APL of a second virtual machine 33 and the operation of the second virtual machine stops, the diagnosis unit 342 of the third virtual machine 34 can detect the abnormality (operational stop) of the second virtual machine 33.

[0086] (4) According to a fourth aspect, in the control system 3 relating to any one of the first to third aspects, the first virtual machine 32 further has a second communication unit 322 that acquires data of the control target 10 and control instructions calculated in the second virtual machine 33 and transmits them to the higher-level device 4.

[0087] This allows the control system 3 to transmit the calculation results of each control APL to a higher-level device 4 such as a plant analysis system or a remote control terminal. The second communication unit 322 of the first virtual machine 32 may also transmit the diagnosis result of the diagnosis unit 342 of the third virtual machine 34 to the higher-level device 4. This allows an operator or the like to quickly recognize that an abnormality has occurred in the control system 3.

[0088] (5) According to a fifth aspect, a control method is a control method using a control system in which a physical machine having a plurality of virtual machines controls each of a plurality of control objects, and includes the steps of a first virtual machine, which is at least one of the plurality of virtual machines, communicating with each of the plurality of control objects, receiving data used to control the control objects, and sending control instructions to the control objects; a step in which the first virtual machine distributes the data received from the control objects to other virtual machines; and a step in which a second virtual machine, which is different from the first virtual machine, among the plurality of virtual machines, issues control instructions to the control objects based on an analysis result of the data.

[0089] According to the above aspect, functions can be consolidated into one physical machine, thereby reducing costs and installation space, and also reducing resources used by the entire system.

[0090] REFERENCE SIGNS LIST 1 Plant system 10 Control target 2 Control device 3 Control system 31 Physical machine 32 First virtual machine 321 First communication unit 322 Second communication unit 323 Common data management unit 324 Distribution unit 33 Second virtual machine 331 Arithmetic processing unit 34 Third virtual machine 341 Diagnostic data collection unit 342 Diagnosis unit 344 Log collection unit 4 Upper device

Claims

1. A control system for controlling multiple control objects using a physical machine having multiple virtual machines, comprising: a first virtual machine which is at least one of the multiple virtual machines and has a first communication unit which communicates with each of the multiple control objects, receives data used to control the control object and sends control instructions to the control object, and a distribution unit which distributes the data received from the control object to the other virtual machines; and a second virtual machine which is one of the multiple virtual machines and different from the first virtual machine, and has a calculation processing unit which issues control instructions to the control object based on the analysis results of analyzing the data.

2. The control system described in claim 1, wherein each of the multiple second virtual machines corresponds to each of the multiple control objects, and the distribution unit of the first virtual machine distributes the data of the control objects to the corresponding second virtual machine.

3. The control system of claim 1, further comprising a third virtual machine, at least one of the plurality of virtual machines, having a diagnostic unit that diagnoses the operation of the first virtual machine and the second virtual machine based on diagnostic data collected from each of the first virtual machine and the second virtual machine.

4. A control system as described in any one of claims 1 to 3, wherein the first virtual machine further has a second communication unit that acquires the data of the control target and the control instructions calculated in the second virtual machine and transmits them to a higher-level device.

5. A control method using a control system in which a physical machine having a plurality of virtual machines controls each of a plurality of control objects, the control method comprising the steps of: a first virtual machine which is at least one of the plurality of virtual machines communicating with each of the plurality of control objects, receiving data used to control the control objects, and sending control instructions to the control objects; a step in which the first virtual machine distributes the data received from the control objects to the other virtual machines; and a step in which a second virtual machine among the plurality of virtual machines, different from the first virtual machine, issues control instructions to the control objects based on an analysis result of the data.

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