Autonomous distribution type system, global distribution system, and control method of autonomous distribution type system

Abstract

To prevent omission of data to be transmitted and received among control devices in design change of a system.SOLUTION: The present application relates to an autonomous distribution type system with a plurality of control devices connected with one another via a network. Each of the plurality of control devices prepares a request command for requesting, among input elements and output elements attached with an identifier to be commonly used among the plurality of control devices, the input element of which the output elements corresponding to the input element does not exist in an own control device from other control devices. At least a part of the request command is divided into at least one sub-request command of which the number of output elements to be requested becomes an acceptance upper limit value or less to be transmitted to other control devices when the number of output elements to be requested included in the request command exceeds the acceptance upper limit values of other control devices. The output element is acquired from other control devices according to at least either of the request command, or the plurality of sub-request commands.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an autonomous decentralized system, a global decentralized system, and a control method for an autonomous decentralized system. [Background technology]

[0002] Distributed systems consisting of multiple control devices are known. In this type of distributed system, control logic installed in each control device is executed, thereby realizing distributed cooperative control, in which multiple control devices cooperate to control a predetermined purpose. In distributed cooperative control, data is transmitted and received between control devices. For example, if a control device does not have necessary data, it can send a request command to another control device to request reference to the data, and receive the data from the other control device in response.

[0003] For example, Patent Document 1 discloses technology relating to an autonomous distributed system that, when a data change occurs in a distributed system due to a design change or the like, can continue operating the system without stopping it when a design change occurs by querying other control devices via groupcast communication for data that does not exist in the control device itself. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3930404 Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, in a distributed system, each control device transmits a request command corresponding to data not present in its own control device to other control devices. The request command includes multiple request elements corresponding to the number of data points to be requested (number of requests). Meanwhile, in other control devices that receive such a request command, an upper limit (hereinafter referred to as "upper acceptance limit") is set for the number of requests that can be responded to, depending on the network connecting the control devices and the specifications of the control devices themselves. Therefore, the number of requests included in the request command is set to be equal to or less than the upper acceptance limit set in the other control device that is the transmission destination.

[0006] Here, a design change to at least part of the distributed system may change the upper limit of acceptance for at least some of the control devices, resulting in a request command sent from one control device exceeding the upper limit of acceptance for other control devices. In this case, the request commands exceeding the upper limit may be deemed invalid or invalid, resulting in the entire request command being discarded, and necessary data may be lost between the control devices that make up the distributed system. This data loss may cause the distributed cooperative control in the distributed system to become impossible, potentially leading to an emergency shutdown of the controlled object.

[0007] At least one embodiment of the present disclosure has been made in consideration of the above-mentioned circumstances, and aims to provide an autonomous decentralized system, a global decentralized system, and a control method for an autonomous decentralized system that can prevent data transmitted and received between control devices from being lost when the system design is changed. [Means for solving the problem]

[0008] In order to solve the above problem, an autonomous decentralized system according to at least one embodiment of the present disclosure includes: An autonomous distributed system having a plurality of control devices connected via a network, Each of the plurality of control devices a request command creation unit that creates a request command to request another control device to provide an input element and an output element that are assigned an identifier commonly used by the plurality of control devices and that does not have a corresponding output element in the control device itself; a transmitting unit that, when the number of requests for the output elements included in the request command exceeds an upper limit of acceptance by the other control device, divides at least a part of the request command into at least one sub-request command, the number of requests for the output elements being equal to or less than the upper limit of acceptance, and transmits the sub-request command to the other control device; an acquisition unit that acquires the input element from the other control device in response to at least one of the request command and the plurality of sub-request commands; Equipped with.

[0009] In order to solve the above problem, a global distributed system according to at least one embodiment of the present disclosure includes: A plurality of autonomous distributed systems according to at least one embodiment of the present disclosure are connected via the Internet.

[0010] In order to solve the above problem, a control method for an autonomous decentralized system according to at least one embodiment of the present disclosure includes: A control method for an autonomous distributed system having a plurality of control devices connected via a network, comprising: Each of the plurality of control devices a step of creating a request command to request, from another control device, an input element and an output element to which an identifier commonly used by the plurality of control devices is assigned, the input element for which the output element corresponding to the input element does not exist in the control device itself; When the number of requests for the output elements included in the request command exceeds an upper limit of acceptance of the other control device, dividing at least a part of the request command into at least one sub-request command, the number of requests for the output elements being equal to or less than the upper limit of acceptance, and transmitting the sub-request command to the other control device; acquiring the input element from the other control device in response to at least one of the request command and the plurality of sub-request commands; Equipped with. [Effects of the Invention]

[0011] According to at least one embodiment of the present disclosure, it is possible to provide an autonomous distributed system, a global distributed system, and a control method for an autonomous distributed system that can prevent data transmitted and received between control devices from being lost when the system design is changed. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is an overall configuration diagram of an autonomous decentralized system according to an embodiment; [Figure 2] FIG. 2 is a block diagram of the control device of FIG. 1. [Figure 3] 1 is a flowchart illustrating a control method for an autonomous decentralized system according to an embodiment. [Figure 4] 4 is a flowchart showing in detail each process in steps S102 to S104 of FIG. 3. [Figure 5] FIG. 5 is an explanatory diagram of each step in FIG. 4. [Figure 6] 10 is another flowchart showing in detail each process in steps S102 to S104 of FIG. 3. [Figure 7] FIG. 7 is an explanatory diagram of each step in FIG. 6. [Figure 8] 1 is a schematic configuration diagram of a globally distributed system according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, several embodiments of the present invention will be described with reference to the accompanying drawings. However, the configurations described as the embodiments or shown in the drawings are merely illustrative examples and are not intended to limit the scope of the present invention.

[0014] 1 is an overall configuration diagram of an autonomous distributed system 1 according to one embodiment. The autonomous distributed system 1 includes a plurality of control devices 4 connected via a network 2. In this embodiment, an example of the autonomous distributed system 1 includes three control devices 4A, 4B, and 4C as the plurality of control devices 4, but the autonomous distributed system 1 only needs to include at least two control devices 4, and the number of control devices 4 is not limited.

[0015] Each of the multiple control devices 4 is installed with control logic that enables the autonomous decentralized system 1 to perform predetermined functions by working together to perform distributed cooperative control. Each control device 4 executes the control logic to perform predetermined arithmetic processing. The control logic includes input elements that represent input data required for the arithmetic processing, and output elements that represent output data output from the arithmetic processing.

[0016] Input elements and output elements are assigned global identifiers that are shared by multiple control devices 4. By using global identifiers in this way, even if an output element having a specific identifier is distributed across multiple control devices 4, it can be uniquely identified without specifying the control device 4 that has the output element. In FIG. 1, such differences in identifiers are schematically represented by shapes such as circles, squares, and triangles. Also in FIG. 1, the shapes connected to the end points of the arrows represent output elements, and the shapes connected to the start points of the arrows represent input elements.

[0017] The design of the autonomous decentralized system 1 can be updated by a design tool 6. The design tool 6 is connected via a network 2, and when, for example, the number or specifications of the control devices 4 constituting the autonomous decentralized system 1 are changed, new control logic can be provided to each control device 4 to realize distributed cooperative control appropriate for the new design change. The design tool 6 performs a process of assigning unique identifiers to input elements newly generated as a result of the design change. A database 8 connected to the design tool 6 manages global identifiers so that they are not duplicated. The design tool 6 refers to this database 8 to assign global identifiers to input elements or output elements newly generated as a result of the design change.

[0018] Each control device 4 has an input / output element management table 10 for managing the input elements and output elements of the control device itself. The input / output element management table 10 classifies and expands the input elements and output elements handled by the control device itself, for example, when the autonomous decentralized system 1 is started up or when there is a design change in the autonomous decentralized system 1. At this time, input elements that do not have a corresponding output element in the control device itself are extracted and registered in an unresolved list.

[0019] 1, input element 12 of control device 4A is not registered in the unresolved list because it is completed by the existence of output element 14 with the same identifier within the control device itself. On the other hand, input element 16 of control device 4A is registered in the unresolved list because there is no output element with the same identifier within the control device itself (note that output element 18 with the same identifier as input element 16 exists in another control device 4B, which is not the control device itself, as viewed from the control device 4A).

[0020] Similarly, the input element 19 possessed by the control device 4B is registered in the unresolved list because there is no output element with the same identifier within the control device itself (note that the output element 20 with the same identifier as the input element 19 exists in another control device 4C, which is not the control device itself for the control device 4B).

[0021] Next, we will explain the functional configuration realized by executing the control logic in each control device 4. Figure 2 is a block configuration diagram of the control device 4A in Figure 1. In the following explanation, we will explain the control device 4A as a representative of the multiple control devices 4 provided in the autonomous decentralized system 1, but unless otherwise specified, the other control devices 4B and 4C also have the same function.

[0022] The control device 4A includes an input / output management unit 21, a request command creation unit 22, a transmission unit 24, and an acquisition unit .

[0023] The input / output management unit 21 is configured to manage input elements and output elements handled by the control device itself. Specifically, the input / output management unit 21 classifies and expands the input elements and output elements handled by the control device itself in the input / output element management table 10, extracts input elements that do not have corresponding output elements in the control device itself, and registers them in an unsolved list.

[0024] The request command creation unit 22 is configured to create a request command D for requesting the other control devices 4B and 4C for an input element for which the control device itself does not have a corresponding output element. An input element for which the control device 4A does not have a corresponding output element can be identified based on an unsolved list registered in the input / output management unit 21. Generally, an unsolved list contains multiple input elements for which the control device itself does not have a corresponding output element, and therefore the request command D includes multiple requests for the other control devices 4B and 4C (hereinafter, each request included in the request command D will be referred to as a "request element d," and the number of request elements d included in the request command D will be referred to as the "number of requests k").

[0025] The transmitter 24 is configured to transmit the request command D created by the request command creator 22 to the other control devices 4B and 4C. The request command D is transmitted simultaneously to all other control devices 4B and 4C included in the autonomous decentralized system 1 by, for example, groupcast communication. Upon receiving the request command D, the other control devices 4B and 4C return a response signal R in accordance with the request command D.

[0026] The acquiring unit 26 is configured to receive response signals R from the other control devices 4B and 4C to acquire data corresponding to request elements d included in the response signal R (output elements in the control device 4A that correspond to input elements for which the corresponding output elements do not exist in the control device itself). When the other control devices 4B and 4C receive a request command D from the control device 4A, they refer to their own input / output element management tables 10 to determine whether they have data corresponding to each request element d included in the request command D. If they have data corresponding to each request element d, they create a response signal R including the data and transmit it to the control device 4A that sent the request command D. By receiving the response signals R transmitted from the other control devices 4B and 4C in this way, the acquiring unit 26 acquires the data included in the response signal R.

[0027] Here, the request command D includes request elements d with a request count k. Meanwhile, an upper limit (hereinafter referred to as an "upper limit j") is set for the number of requests k that can be accepted in each control device 4. This upper limit j is a parameter set according to the specifications of each control device 4 and the network. In the autonomous distributed system 1, initially, each control device 4 constituting the autonomous distributed system 1 has a common upper limit j. However, a subsequent design change may cause the upper limit j of at least some of the control devices 4 to change, resulting in the inclusion of control devices 4 with different upper limit j. In this case, the number of requests k included in the request command D transmitted from a certain control device 4A may exceed the upper limit j of the other control devices 4B and 4C. In this case, the other control devices 4B and 4C may not be able to properly process the request command D from the control device 4A. For example, data corresponding to the number of request elements d exceeding the upper limit j may be missing, or the request command D may be deemed to be invalid and discarded.

[0028] To solve this problem, when the number of requests k included in the request command D exceeds the upper acceptance limit j of the other control devices 4B and 4C, the transmitting unit 24 of this embodiment divides at least a part of the request command D created by the request command creating unit 22 into sub-request commands SD including a number of requests k equal to or less than the upper acceptance limit j. In this case, the transmitting unit 24 may divide the entire request command D into a plurality of sub-request commands SD, or may divide a part of the request command D (for example, only the range of the request command D that exceeds the upper acceptance limit j of the other control devices 4B and 4C) into the sub-request commands SD.

[0029] In addition, in the control device 4A, the upper acceptance limit value j of the other control devices 4B and 4C may be input by an operator, or may be determined based on the response signal R obtained when a request signal D is first sent to the other control devices 4B and 4C.

[0030] Next, a description will be given of a control method for the autonomous decentralized system 1 having the above configuration. Fig. 3 is a flowchart showing a control method for the autonomous decentralized system 1 according to one embodiment.

[0031] 3 is called at the time of initialization or design change when the autonomous decentralized system 1 is started up. The design change may be made to at least some of the components of the autonomous decentralized system 1, or may be a design change accompanied by a change in the upper acceptance limit value j of at least some of the control devices 4.

[0032] When the autonomous decentralized system 1 is started, the input / output element management unit 21 creates an unregistered list based on the input / output element management table 10 of the control device 4A (step S100). In step S100, the unregistered list is created by referring to the input / output element management table 10 to identify input elements for which no output element corresponding to the input element exists in the control device itself.

[0033] Next, a request command D is created based on the unregistered list created in step S100 (step S101). This request command D is created as a command to request the input elements registered in the unregistered list from the other control devices 4B and 4C, and is created including request elements d with a request count k.

[0034] Next, if the number of requests k included in the request command D created in step S101 exceeds the upper acceptance limit j of the other control devices 4B and 4C, the transmitter 24 creates a sub-request command SD by dividing at least a part of the request command D (step S102). The sub-request command SD is created by dividing the request command D so as to include a number of requests equal to or less than the upper acceptance limit j of the other control devices 4B and 4C. If the number of requests k included in the request command D is equal to or less than the upper acceptance limit j of the other control devices 4B and 4C, step S102 is omitted.

[0035] Next, the transmitter 24 transmits at least one of the request command D created in step S101 and the sub-request command SD created in step S102 to the other control devices 4B and 4C (step S103). In step S103, if at least one sub-request command SD has been created from the request command D in step S102, the transmitter 24 may transmit the sub-request command SD together with the request command D, or may transmit the sub-request command SD after transmitting the request command D. Furthermore, if no sub-request command SD has been created in step S102, only the request command SD may be transmitted. The transmission in step S103 is performed by groupcast communication to the other control devices 4B and 4C.

[0036] Next, the acquisition unit 26 receives a response signal R transmitted from the other control devices 4B and 4C in response to at least one of the request command D and the sub-request command SD transmitted in step S103 (step S104). The response signal R includes data corresponding to each request element d included in the request command D, and by acquiring this data, the acquisition unit 26 can obtain data registered in the unregistered list (i.e., output elements in the control device 4A that do not have corresponding input elements in the control device itself) from the other control devices 4B and 4C.

[0037] 3 illustrates an example in which steps S102 to S104 are performed in order for convenience of explanation, but steps S102 to S104 may be performed independently, or each step may be performed multiple times. For example, as in an embodiment described later with reference to FIGS. 4 and 6, after receiving a response signal R corresponding to the transmission of some request commands D or sub-request commands SD, transmission of other request commands D or sub-request commands SD and reception of the response signal R corresponding to the transmission may be repeated. Furthermore, the process of dividing at least some of the request commands D into sub-request commands SD may be performed independently of the process of transmitting the request commands D or sub-request commands SD and the process of receiving the response signal R corresponding to the transmission.

[0038] Next, a more specific embodiment will be described with respect to each process in steps S102 to S104 in Fig. 3. Fig. 4 is a flowchart showing in detail each process in steps S102 to S104 in Fig. 3, and Fig. 5 is an explanatory diagram of each step in Fig. 4.

[0039] In this embodiment, first, the transmitter 24 acquires (step S200) the upper acceptance limit values ​​of the multiple control devices 4A, 4B, and 4C included in the autonomous decentralized system 1. In the example of Fig. 5, of the three control devices 4A, 4B, and 4C included in the autonomous decentralized system 1, the upper acceptance limit value j of the control device 4A has been extended from a first value j1 (= 1200) to a second value j2 (= 2400) due to a design change, and the upper acceptance limit values ​​of the other control devices 4B and 4C have the first value (= 1200).

[0040] Next, the autonomous decentralized system 1 identifies the smallest upper acceptance limit value from the upper acceptance limit values ​​j of each control device 4 acquired in step S202 (step S201). In the example of Fig. 5, the first value j1, which is the upper acceptance limit value of the control devices 4B and 4C, is smaller than the second value j2, which is the upper acceptance limit value of the control device 4A, and therefore the first value j1 is identified as the smallest upper acceptance limit value.

[0041] Next, the number of requests k included in the request command D (i.e., the request command D created in step S101 of FIG. 3) sent from the control device 4A to the other control devices 4B and 4C is identified (step S202). As described above, the request command of the control device 4A is created based on the unregistered list related to the control device 4A, and includes the number of requests k that exceeds the first value j1, which is the upper limit of acceptance for the other control devices 4B and 4C. In the example of FIG. 5, the request command D includes the number of requests k of 1800 points, which exceeds the upper limit of acceptance for the other control devices 4B and 4C, 1200 points.

[0042] Next, the transmitting unit 24 calculates a division number Nd for dividing the request command D into a plurality of sub-request commands SD based on the minimum upper-limit acceptance value identified in step S201 and the number of requests k identified in step S202 (step S203). The division number is calculated, for example, as a quotient when the number of requests k included in the request command D is divided by the minimum upper-limit acceptance value (note that the remainder is rounded up). In the example of FIG. 5, the request command D including the number of requests k of 1800 points is calculated as the division number Nd of "2" based on the minimum upper-limit acceptance value of 1200 points (the request command D can be divided into a first sub-request command SD1 including request elements d of 1 to 1200 points and a second sub-request command SD2 including request elements d of 1201 to 1800 points).

[0043] Next, the transmitter 24 sets the increment N to an initial value "1" (step S204), and divides the request command D to create a first sub-request command SD (step S205), which is then transmitted to the other control devices 4B and 4C (step S206).Then, based on the response signals RB and RC received from the other control devices 4B and 4C, the acquirer 26 can acquire data included in the response signals RB and RC (i.e., output elements in the control device 4A that do not have corresponding input elements in the control device itself) from the other control devices 4B and 4C (step S207).

[0044] Next, "1" is added to the increment N (step S208), and it is determined whether the increment N is greater than the division number Nd calculated in step S203 (step S209). If the increment N is equal to or less than the division number Dd (step S209: NO), the process returns to step S205, where the next sub-request command SD is created. Steps S205 to S209 are repeated until the increment N becomes greater than the division number Nd.

[0045] 5, a request command D including a request number k of 1800 points is first divided into a first sub-request command SD1 including 1st to 1200th request elements d as the first sub-request command. The first sub-request command SD1 is transmitted to the other control devices 4B and 4C, thereby obtaining response signals RB and RC from the other control devices 4B and 4C, respectively. Specifically, in response to the first sub-request command SD1 including 1200 request elements d, the control device 4B outputs a response signal RB including 800 output elements, and the control device 4C outputs a response signal RC including the remaining 400 output elements.

[0046] Next, as the second sub-request command SD, the remaining request command D including the request number k of 600 points after the first sub-request command SD1 is divided is divided as a second sub-request command SD2 including request elements d of 1201 to 1800 points. The second sub-request command SD2 is transmitted to the other control devices 4B and 4C, and response signals RB and RC are obtained from the other control devices 4B and 4C, respectively. Specifically, in response to the second sub-request command SD2 including the request elements d of 600 points, the control device 4B outputs a response signal RB including output elements of 600 points, while the control device 4C does not respond because the remaining output elements are 0 points (it should be noted that even if the remaining output elements are 0 points, the control device 4C may respond by outputting a response signal RB including an output element of 0 points).

[0047] According to this embodiment, a request command D including a request number k that exceeds the upper acceptance limit of the other control devices 4B and 4C is divided into multiple sub-request commands SD and transmitted to the other control devices 4B and 4C. As a result, the other control devices 4B and 4C can return appropriate data (i.e., output elements in the control device 4A that do not have corresponding input elements in the control device 4A) to the control device 4A that is the sender of the request command D in response to a sub-request command SD including a request number within the upper acceptance limit without any data loss.

[0048] Next, another embodiment will be described with reference to Fig. 6 and Fig. 7. Fig. 6 is another flowchart showing in detail each process in steps S102 to S104 in Fig. 3, and Fig. 7 is an explanatory diagram of each step in Fig. 6.

[0049] In this embodiment, first, the transmitting unit 24 transmits the request command D created by the request command creating unit 22 to the other control device 4B (step S300). This request command D includes a request number k that exceeds the first value j1, which is the upper limit of the number of requests that can be accepted by the other control device 4B. In the example of FIG. 7, the request command D includes a request number k of 1800 points, which exceeds the upper limit of the number of requests that can be accepted by the control device 4B, which is 1200 points. When the other control device 4B receives the request command D from the control device A, it returns a corresponding response signal R.

[0050] The control device 4A receives a response signal RB1 from another control device 4B (step S301). This response signal RB1 includes a response corresponding to the range of the upper acceptance limit j1 of the request number k of the request command D, as well as information about the upper acceptance limit j1 of the control device 4B. In the example of Fig. 7, the request command D includes a request number k of 1800 points, and the response signal RB1 from the control device 4B includes information indicating that the response to the request element d of 1 to 1200 points is 800 points and that the upper acceptance limit j1 of the control device 4B is 1200 points.

[0051] The control device 4A identifies the upper acceptance limit j1 of the other control device 4B based on the response signal RB1 received from the other control device 4B (step S302). That is, by analyzing the response signal RB1 from the other control device 4B, the control device 4A obtains the output element of 800 points returned within the range of the upper acceptance limit j1 of the control device 4B out of the request command D, and also obtains information for identifying that the upper acceptance limit j1 of the control device 4B is 1200 points.

[0052] Next, when it is determined that the number of requests k included in the request command D exceeds the upper acceptance limit j1 based on the upper acceptance limit j1 identified in step S302 (step S303: YES), the transmitter 24 creates at least one sub-request command SD by dividing the request signal D. In step S304, the sub-request command SD is created by dividing the range of the request signal D already transmitted in step S300 that was not properly processed by the other control device 4B. Then, the transmitter 24 transmits the sub-request command SD created in step S304 to the other control device 4B (step S305) and acquires a response signal RB2 to the sub-request command SD (step S306).

[0053] In this embodiment, by dividing the portion of the request command D that exceeds the upper acceptance limit j1 of the other control device 4B into sub-request commands SD and sending them, appropriate data (i.e., output elements in the control device 4A that do not have corresponding input elements in the control device itself) can be returned to the control device 4A that is the sender of the request command D without any data loss.

[0054] Next, a description will be given of a globally distributed system 100 including the autonomous distributed system 1 having the above configuration. Fig. 8 is a schematic diagram of the globally distributed system 100 according to one embodiment.

[0055] The global distributed system 100 is configured by connecting a plurality of autonomous distributed systems 1 via a communication network 200 such as the Internet. In Fig. 8, the plurality of autonomous distributed systems 1 include a first autonomous distributed system 1A, a second autonomous distributed system 1B, and a third autonomous distributed system 1C, which are connected via the communication network 200.

[0056] In the global distributed system 100, the database 8 in each autonomous distributed system 1 is configured as a distributed database, and data identifiers are uniquely managed across the multiple control devices 4 included in each autonomous distributed system 1. As a result, similar to the above-described embodiment, even between the multiple control devices 4 that configure each autonomous distributed system 1 (i.e., the multiple control devices 4 that configure the first autonomous distributed system 1A, the multiple control devices 4 that configure the second autonomous distributed system 1B, and the multiple control devices 4 that configure the third autonomous distributed system 1C), if the number of requests k included in the request command D exceeds the upper limit of acceptance by other control devices 4, at least a part of the request command D is divided into sub-request commands SD and transmitted, thereby making it possible for the multiple control devices 4 that configure different autonomous distributed systems 1 to refer to input elements for which a corresponding output element does not exist in their own control devices without data loss.

[0057] In addition, within the scope of the present disclosure, the components in the above-described embodiments may be replaced with well-known components as appropriate, and the above-described embodiments may be combined as appropriate.

[0058] The contents described in each of the above embodiments can be understood, for example, as follows.

[0059] (1) An autonomous decentralized system according to one aspect includes: An autonomous distributed system having a plurality of control devices connected via a network, Each of the plurality of control devices a request command creation unit that creates a request command to request another control device to provide an input element and an output element that are assigned an identifier commonly used by the plurality of control devices and that do not have an output element corresponding to the input element in the control device itself; a transmitting unit that, when the number of requests for the output elements included in the request command exceeds an upper limit of acceptance by the other control device, divides at least a part of the request command into at least one sub-request command, the number of requests for the output elements being equal to or less than the upper limit of acceptance, and transmits the sub-request command to the other control device; an acquisition unit that acquires the input element from the other control device in response to at least one of the request command and the plurality of sub-request commands; Equipped with.

[0060] According to the above aspect (1), in each of the multiple control devices constituting the autonomous distributed system, if an output element corresponding to an input element does not exist in the control device itself, a request command is created to request the input element from the other control devices. If the number of requested output elements included in the request command exceeds the upper limit of acceptance by the other control devices, at least a portion of the request command is divided into sub-request commands including a number of requests equal to or less than the upper limit of acceptance and transmitted to the other control devices. This allows the other control devices to appropriately return response signals to the sub-request commands including a number of requests equal to or less than the upper limit of acceptance. This allows input elements corresponding to the request elements included in the request command to be appropriately acquired from the other control devices without data loss between the control devices.

[0061] (2) In another embodiment, in the above embodiment (1), When the upper acceptance limit value of at least some of the plurality of control devices is changed, the transmission unit determines whether the output element corresponding to the input element exists in the control device itself.

[0062] According to the above aspect (2), when the upper acceptance limit value of at least some of the control devices constituting the autonomous distributed system is changed, at least some of the request commands including the number of requests exceeding the changed upper acceptance limit value are divided into sub-request commands and transmitted to the other control devices. As a result, even when a request command including the number of requests exceeding the upper acceptance limit value of the other control devices is created due to a design change, input elements corresponding to the request elements included in the request command can be suitably acquired from the other control devices without causing data loss between the control devices.

[0063] (3) In another aspect, in the above aspect (1) or (2), The transmission unit transmits the plurality of sub-request commands created by dividing the request command to the other control devices.

[0064] According to the above aspect (3), a request command including a number of requests exceeding the upper limit of the reception value of another control device is divided into multiple sub-request commands and transmitted to the other control device, thereby allowing the other control device to suitably acquire input elements corresponding to the request elements included in the request command from the other control device for a sub-request command including a number of requests within the upper limit of the reception value without causing data loss between the control devices.

[0065] (4) In another embodiment, in the above embodiment (3), The transmitting unit divides the request command based on the smallest upper acceptance limit value among the other control devices.

[0066] According to the above aspect (4), when there are multiple other control devices to which a request command is to be sent, the request command is divided based on the smallest upper limit acceptance value among these other control devices. As a result, the request command created by the control device is divided into sub-request commands each containing a request number equal to or less than the upper limit acceptance value and sent to all other control devices.

[0067] (5) In another aspect, in the above aspect (1) or (2), The transmission unit When the request command is transmitted to the other control device, the reception upper limit value of the other control signal is identified based on a response signal received from the other control device; The range of the request signal that exceeds the upper acceptance limit is transmitted to the other control device as the sub-request command.

[0068] According to the above aspect (5), when a request command created by a control device is transmitted to another control device, the upper acceptance limit of the other control device is identified based on a response signal received from the other control device. Based on the identified upper acceptance limit, the transmitter divides the range of the request signal that exceeds the upper acceptance limit into sub-request commands and transmits them to the other control device. In this way, by retransmitting the portion of the request signal that exceeds the upper acceptance limit of the other control device as sub-request commands, input elements corresponding to request elements included in the request command can be suitably acquired from the other control device without data loss between the control devices.

[0069] (6) In another embodiment, in the above embodiment (5), The other control device transmits the output element to the control device within the range of the upper acceptance limit value in response to the request command, and transmits information regarding the upper acceptance limit value as the response signal.

[0070] According to the above aspect (6), when a control device transmits a request command including a number of requests exceeding the upper limit of acceptance to another control device, the other control device transmits, as a response signal, information about its own upper limit of acceptance together with output elements within the range of the upper limit of acceptance. This allows each control device to suitably identify the upper limit of acceptance of the other control device and divide the request command into sub-request commands according to the upper limit of acceptance.

[0071] (7) In another embodiment, in any one of the above (1) to (6), The transmitting unit transmits the at least one sub-request command to the other control devices by groupcast communication.

[0072] According to the above aspect (7), when there are multiple other control devices, sub-request commands obtained by dividing at least a part of the request command are transmitted to these other control devices by groupcast communication, thereby making it possible to suitably obtain input elements corresponding to the request elements included in the request command from the other control devices without causing data loss between the control devices.

[0073] (8) A globally distributed system according to one aspect includes: A plurality of autonomous distributed systems according to any one of the above aspects (1) to (7) are connected via the Internet.

[0074] According to the above aspect (8), in a global distributed system constructed by connecting multiple autonomous distributed systems according to the aforementioned aspects via the Internet, input elements corresponding to the request elements included in the request command can be suitably acquired from other control devices without causing data loss between the multiple control devices constituting each autonomous distributed system.

[0075] (9) A control method for an autonomous decentralized system according to one aspect includes: A control method for an autonomous distributed system having a plurality of control devices connected via a network, comprising: Each of the plurality of control devices a step of creating a request command to request, from another control device, an output element that does not exist in the control device corresponding to the input element among input elements and output elements that are assigned identifiers that are commonly used among the plurality of control devices; When the number of requests for the output elements included in the request command exceeds an upper limit of acceptance of the other control device, dividing at least a part of the request command into at least one sub-request command, the number of requests for the output elements being equal to or less than the upper limit of acceptance, and transmitting the sub-request command to the other control device; acquiring the input element from the other control device in response to at least one of the request command and the plurality of sub-request commands; Equipped with.

[0076] According to the above aspect (9), in each of the plurality of control devices constituting the autonomous distributed system, if an output element corresponding to an input element does not exist in the control device itself, a request command is created to request the input element from the other control devices. If the number of requested output elements included in the request command exceeds the upper acceptance limit of the other control devices, at least a portion of the request command is divided into sub-request commands including a request number equal to or less than the upper acceptance limit and transmitted to the other control devices. This allows the other control devices to appropriately return response signals to the sub-request commands including a request number equal to or less than the upper acceptance limit. This allows input elements corresponding to the request elements included in the request command to be suitably acquired from the other control devices without data loss between the control devices. [Explanation of symbols]

[0077] 1. Autonomous decentralized system 2 Network 4. Control device 6. Design Tools 8 Database 10 Input / Output Element Management Table 21 Input / output management section 22 Request command creation unit 24 Transmitter 26 Acquisition Department 100 Globally Distributed Systems 200 Communication Network

Claims

1. An autonomous distributed system having a plurality of control devices connected via a network, Each of the plurality of control devices a request command creation unit that creates a request command to request another control device to provide an input element and an output element that are assigned an identifier commonly used by the plurality of control devices and that does not have a corresponding output element in the control device itself; a transmitting unit that, when the number of requests for the output elements included in the request command exceeds an upper limit value of reception of the other control device, divides at least a part of the request command into at least one sub-request command, the number of requests for the output elements being equal to or less than the upper limit value of reception, and transmits the sub-request command to the other control device; an acquisition unit that acquires the input element from the other control device in response to at least one of the request command and the plurality of sub-request commands; An autonomous decentralized system equipped with:

2. The autonomous decentralized system of claim 1, wherein the transmission unit determines whether the output element corresponding to the input element exists within the control device when the upper acceptance limit value of at least some of the multiple control devices is changed.

3. The autonomous decentralized system according to claim 1 , wherein the transmission unit transmits the plurality of sub-request commands created by dividing the request command to the other control devices.

4. The autonomous decentralized system according to claim 3 , wherein the transmission unit divides the request command based on the smallest upper acceptance limit value among the other control devices.

5. The transmission unit When the request command is transmitted to the other control device, the reception upper limit value of the other control signal is identified based on a response signal received from the other control device; The autonomous decentralized system according to claim 1 or 2, wherein a range of the request signal that exceeds the upper acceptance limit is transmitted to the other control device as the sub-request command.

6. 6. The autonomous decentralized system according to claim 5, wherein the other control device transmits the output element to the control device within the range of the upper acceptance limit value in response to the request command, and transmits information regarding the upper acceptance limit value as the response signal.

7. The autonomous decentralized system according to claim 1 , wherein the transmitting unit transmits the at least one sub-request command to the other control devices by groupcast communication.

8. 3. A global distributed system in which a plurality of autonomous distributed systems according to claim 1 or 2 are connected via the Internet.

9. A control method for an autonomous distributed system having a plurality of control devices connected via a network, comprising: Each of the plurality of control devices a step of creating a request command to request, from another control device, an input element and an output element to which an identifier commonly used by the plurality of control devices is assigned, the input element for which the output element corresponding to the input element does not exist in the control device itself; When the number of requests for the output elements included in the request command exceeds an upper limit of acceptance of the other control device, dividing at least a part of the request command into at least one sub-request command, the sub-request command having a number of requests for the output elements equal to or less than the upper limit of acceptance, and transmitting the sub-request command to the other control device; acquiring the input element from the other control device in response to at least one of the request command and the plurality of sub-request commands; A control method for an autonomous decentralized system, comprising:

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