JP6483592B2 - Controller and control system - Google Patents

Description

  Embodiments described herein relate generally to a controller and a control system.

  A control system that manages buildings, factories, and the like (hereinafter unified with buildings) performs control called feedback control. For example, feedback control is used to control a valve that regulates the flow rate of water.

  A system that realizes feedback control (feedback control system) includes a controller that performs control, devices to be controlled, and a network that connects them.

Feedback control is control that repeats the following processing.
1. Controller obtains device status via network
2. The controller calculates the control value based on the control value
3. The controller sets the control value to the device via the network.

  The feedback control system is required to have a high operating rate. For example, 99.999% or 99.9999%. In order to satisfy this requirement, an existing feedback control system uses a dedicated hardware to implement a controller. In addition, the controller and the device are in the same building. Therefore, the network communication delay is small.

  Moving the controller to the cloud computing environment can be expected to reduce the cost of the feedback control system. However, the network delay between the controller and the device increases. Feedback control becomes difficult when communication delays and dispersion of communication delays increase. In order to perform accurate feedback control from the cloud, it is necessary to grasp the communication delay. By calculating the control value in consideration of the communication delay, accurate feedback control can be performed even in an environment where the communication delay is large.

  In addition, the operation rate of a general public cloud is about 99.95% or 99.99%, and the operation rate of a general long-distance dedicated network is also the same. Therefore, it is necessary to make the controller and the network redundant in order to use the public cloud to make the operation rate of the feedback control system 99.999% or 99.9999%.

  The following are known as related technologies for transferring a controller to the cloud. Prepare multiple sets of controllers and networks. A priority is set between the controllers, and the controller with the higher priority becomes “primary” and performs feedback control. The non-primary controller does not control, but periodically acquires the device status. Since communication delay can be measured during communication when acquiring the status, all controllers can grasp the communication delay. When a failure occurs in the primary controller, the controller having the next highest priority becomes the primary instead and performs control. This "other controller takes over control" is generally called failover.

  In order to realize failover between controllers, a gateway is installed in the building. The gateway holds information regarding a control status indicating which controller has performed control on which device. And when a controller acquires the state of an apparatus, the information regarding the state of an apparatus and a control condition is returned together. Thereby, the controller group can grasp “the primary controller is performing control”. When the primary controller determines that the control has not been performed for a while, a failover occurs. Thereby, a high operation rate is achieved.

  In the related technology described above, it is necessary to install a high-function gateway that stores the control status of the device. This increases the development cost of the gateway and hinders cost reduction of the system. This is because in order to maintain the control status, computer resources such as a CPU and a memory for that purpose are required. In addition, installing a device for maintaining the control status on the building side hinders cost reduction and flexibility improvement of the feedback control system.

Industrial Automation as a Cloud Service IEEE Transactions on Parallel and Distributed Systems, No.10, Vol.26, pp.2750-2763 (2015)

  An object of the embodiment of the present invention is to make it possible to realize a feedback control system having a high operation rate without using a cloud and using a high-performance gateway.

  A controller as an embodiment of the present invention includes a device state acquisition unit, a storage unit, a control unit, a measurement unit, a communication unit, a controller state determination unit, and a determination unit.

  The device status acquisition unit acquires device status information via the first network.

  The storage unit stores information on whether or not it has a first role of controlling the device for each of its own device and other controllers.

  When the own device has the first role, the control unit controls the device based on the state information of the device.

  The measurement unit measures first information related to communication quality of the first network.

  The communication unit transmits a first message including the first information to the other controller via a second network, and relates to communication quality of a third network from the other controller to the device. A second message including second information is received via the second network.

  The controller state determination unit determines the state of the other controller by communicating with the other controller via the second network.

  The determination unit determines the controller of the first role from the own apparatus and the other controller based on the state of the other controller and the first information and the second information.

The figure which shows the structural example of the network which concerns on embodiment of this invention. The figure which shows the other structural example of the network which concerns on embodiment of this invention. The block diagram which shows the structural example of the controller which concerns on embodiment of this invention. The data structure example of a controller information storage part is shown. The figure which shows the hardware structural example of a controller. The flowchart of an example of the monitoring control process. Flow chart of an example of heartbeat transmission processing The figure which shows the 1st example of the operation | movement flowchart of a heartbeat reception process. The figure which shows the 2nd example of the operation | movement flowchart of a heartbeat reception process. The figure which shows the structural example of the network for survival confirmation.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 shows a configuration example of a network according to the present embodiment. A device 11 and a gateway 12 that are subject to feedback control are arranged in a building, a factory, or the like (hereinafter, unified with a building). Although only one device to be controlled is shown in FIG. 1, a plurality of devices may actually be arranged. In this case, each of a plurality of devices may be a target of feedback control.

  A plurality of controllers C1, C2 and C3 are distributed on the cloud outside the building. These controllers C <b> 1 to C <b> 3 are connected to each other via the survival confirmation network 21. The controllers C1 to C3 are connected to the gateway 12 in the building via the control networks 31, 32, and 33, respectively. The controllers C1 to C3 communicate with the equipment 11 in the building via the gateway 12.

  The gateway 12 transfers data or messages between the controllers C1 to C3 and the device 11. For example, the gateway 12 includes a routing function for performing transfer based on an IP address or the like.

  Communication between the gateway 12 and the device 11 may be wireless communication such as a wireless LAN conforming to the IEEE 802.11 standard, or wired communication such as Ethernet (registered trademark).

  The control networks 31, 32, and 33 may be the same network or different networks. An example of the same network is the Internet. In this case, the control networks 31 to 33 correspond to different routes on the Internet. The control networks 31 to 33 may be VPNs (Virtual Private Networks) formed on networks such as the Internet. In this case, it can be said that the control networks 31, 32, and 33 are logically different networks. Of course, the control networks 31, 32, and 33 may be dedicated networks that are physically different (separated) from each other.

  The survival confirmation network 21 is a private network formed by using a communication device arranged in a data center or the like by a network operator as an example. The network may be a wired network, a wireless network, or a mixture of these. The existence confirmation network 21 and the control network are physically different networks. However, the survival confirmation network 21 may be physically the same network as the control network.

  FIG. 2 is a diagram illustrating a configuration in which an operator or administrator's terminal device M is connected to the survival confirmation network 21. By operating this terminal device M, an operator or a management company can manage the operation of the controller such as setting the controllers C1 to C3 and confirming or controlling the operations of the controllers C1 to C3.

  FIG. 3 shows a configuration example of the controllers C1 to C3. Each of the controllers C1 to C3 has the configuration shown in FIG. The controllers C1 to C3 include a monitoring control unit 101, a survival confirmation unit 201, and a controller information storage unit 301.

  The controller information storage unit 301 stores information on its own device and information on other controllers. FIG. 4 shows an example of information stored in the controller information storage unit 301.

  “ID” is an identifier for uniquely identifying a controller.

  “Communication address” is the communication address of the controller. In the example of the figure, an IP address is shown. The communication address may be a set of an IP address and a port number. A communication address corresponding to the communication protocol to be used may be used.

  The “time stamp” represents the time when the controller information is created or updated.

  “Role” represents primary or non-primary. The primary is a role of performing feedback control (hereinafter sometimes simply referred to as control) on the device, and the primary controller controls the device. A controller that does not perform device control (not primary) has a non-primary role.

  “Control network status” indicates whether the control network is normal or abnormal. Normal is an example of good (high) communication quality of the control network, and abnormal is an example of poor (low) communication quality of the control network.

  “Average value of delay of control network” is an average value of communication delay between the controller and the device in the control network. A high communication delay average value is an example of good communication quality of the control network, and a low communication delay average value is an example of poor control network communication quality.

  “Distribution of delay in control network” is distribution of communication delay between the controller and the device in the control network. Low communication delay variance is an example of good communication quality of the control network, and high communication delay variance is an example of poor control network communication quality.

  “Latest device status” represents the latest device status value acquired by the controller.

  The items shown in FIG. 4 are examples, and other items may exist. Also, some of the items in FIG. 4 may not exist.

  The monitoring control unit 101 includes a device state acquisition unit 102, an abnormality determination unit 103, a control network state determination unit 104, a control network delay calculation unit 105, a control unit 111, a control network delay average calculation unit 108, and a control network delay. A variance calculation unit 109 is provided. The control unit 111 includes a control value transmission unit 106 and a control value calculation unit 107.

  The device state acquisition unit 102 acquires information (state information) indicating the state of the device 11 by communicating with the device 11 in the building via the control network and the gateway 12. As an example, the device state acquisition unit 102 acquires state information from the device 11 at regular intervals.

  The abnormality determination unit 103 determines whether the device is normally controlled based on the state information of the device.

  The control network state determination unit 104 determines the state of the control network. More specifically, it is determined whether the control network is normal or abnormal. There are various methods for determining whether a network is normal or abnormal. Here, it is determined that the acquisition of the state information from the device 11 is abnormal when it fails N times consecutively. In this case, it can be said that the communication quality of the network is low (bad).

  The control network delay calculation unit 105 calculates a communication delay of the control network, more specifically, a communication delay between the own apparatus and the device. There are various communication delay calculation methods, and details will be described later.

  The control network delay average calculator 108 calculates the average value of the communication delay of the control network, more specifically, the average value of the communication delay between the own apparatus and the device.

  The control network delay dispersion calculation unit 109 calculates the dispersion of the communication delay of the control network, more specifically, the dispersion of the communication delay between the own apparatus and the device.

  The control unit 111 controls the device 11 based on the state information of the device 11 acquired by the device state acquisition unit 102 and the communication delay of the control network. The control value calculation unit 107 calculates a control value for the device 11 based on the state information of the device 11 and the communication delay of the control network. There are various methods for calculating the control value in the feedback control. As an example, a Smith predictor can be used as the control value calculation unit 107. The Smith predictor can improve the quality of feedback control even in an environment where the communication delay of the network is large by giving a communication delay.

  The control value transmission unit 106 transmits a message including the control value calculated by the control value calculation unit 107 to the device 11. It is assumed that the communication address of the device 11 or the communication address of the gateway 12 or both of these are known in advance. The communication address of the device 11 may be a communication protocol address (IP address or a combination of an IP address and a port number) used by the controller, or may be a communication address of a protocol higher than the communication protocol.

  The existence confirmation unit 201 includes an HB communication unit 202, an ACK (Acknowledgement) communication unit 203, a controller state determination unit 204, and a primary determination unit 205.

  The HB communication unit 202 transmits a survival confirmation message to another controller via the survival confirmation network 21. Hereinafter, the survival confirmation message is described as a heartbeat message or simply a heartbeat (HB). The HB communication unit 202 receives a heartbeat from another controller. The heartbeat includes information in the controller information storage unit 301 in the controller that transmits the heartbeat. As a result, each controller can grasp information related to the communication status or control status of other controllers (communication quality of the control network (normal / abnormal, average / variance of communication delay), device status information, etc.). If the HB communication unit 202 successfully receives and decodes the heartbeat from another controller, the HB communication unit 202 passes to the ACK communication unit 203 that it is necessary to generate a delivery confirmation response (ACK). The HB communication unit 202 transmits a heartbeat at regular intervals. However, the timing for transmitting the heartbeat does not have to be every fixed time, and may be arbitrarily determined when a predetermined event occurs.

  The ACK communication unit 203 receives a delivery confirmation response (ACK) message for the heartbeat transmitted from the HB communication unit 202 of its own device from another controller of the transmission destination. Further, when the heartbeat addressed to its own device transmitted from another controller is received by the HB communication unit 202 and information necessary for generating a delivery confirmation response (ACK) is passed from the HB communication unit 202, based on the information Generate an ACK message. The ACK communication unit 203 transmits the generated ACK message to another controller that has transmitted the heartbeat via the survival confirmation network 21.

The controller state determination unit 204 determines the state of another controller. More specifically, it is determined whether another controller is normal or abnormal. There are various judgment methods. In the present embodiment, when any of the following situations occurs, it is determined as abnormal, and otherwise it is determined as normal.
(1) When heartbeat transmission from the own device to other controllers fails continuously for X times or more (2) After sending heartbeats, ACK cannot be obtained within a certain time, Y times or more, When it occurs continuously. X and Y may be the same value or different values.

  The primary determination unit 205 determines to change the primary when the controller state determination unit 204 detects a primary abnormality, and determines the next primary.

  As an example, in the present embodiment, among the controllers in which the state of the control network is normal, the controller whose variance of communication delay of the control network is the minimum or less than the threshold is set as the primary. For example, when the controller information storage unit 301 is in the state of FIG. 4 and a primary abnormality is detected, the controller with ID = 4 having the smallest variance in communication delay is determined as the primary. The smaller the variance of the network communication delay, the more stable the feedback control, and the communication delay of the wide area network, particularly the Internet, varies. Therefore, stable feedback control can be expected by appropriately updating the information in the controller information storage unit 301 and selecting a controller with a small communication delay variance.

  However, the primary determination method is not limited to this. For example, a controller having an average value of communication delay that is minimum or less than a threshold value may be selected, or an evaluation value calculation formula using the average value and variance of communication delay is prepared, and the evaluation calculated by the calculation formula is used. A controller may be selected based on the value. In addition, as described in the related art described in the background section, it is also possible to select the next primary by setting the priority to each controller.

  FIG. 5 is a diagram illustrating an example of a hardware configuration of the controllers C1 to C3. The controller includes a processor 451, a memory 452, a storage 453, a first network interface 454, and a second network interface 455, which are connected via a bus 456.

  The first network interface 454 is an interface connected to the survival confirmation network 21. As an example, the network interface 454 is a baseband integrated circuit that performs header processing, modulation and demodulation, etc. of a data link layer such as a MAC layer and a physical layer, an AD conversion circuit, a DA conversion circuit, and an integrated circuit that performs analog processing. You may have. A processor such as a CPU may be disposed in the network interface 454. When TCP / IP or the like is used, processing such as TCP / IP may be performed by the CPU on the network interface 454, or may be performed by the processor 451 connected to the bus 456. The controller uses the network interface 454 to communicate with other controllers on the cloud. The network interface 454 may be controlled by the processor 451. The network interface 454 may directly access the memory 452 by DMA (direct memory access).

  The second network interface 455 is an interface connected to the control network. As an example, the network interface 455 is a baseband integrated circuit that performs header processing, modulation and demodulation, etc. of a data link layer such as a MAC layer, and a physical layer, an AD conversion circuit, a DA conversion circuit, and an integrated circuit that performs analog processing. You may have. A processor such as a CPU may be disposed in the network interface 455. When TCP / IP or the like is used, processing such as TCP / IP may be performed by the CPU on the network interface 455 or may be performed by the processor 451 connected to the bus 456. The controller communicates with the gateway 12 and the equipment 11 in the building using the network interface 455. The network interface 455 may be controlled by the processor 451. The network interface 455 may directly access the memory 452 by DMA (direct memory access).

  The memory 452 temporarily stores instructions executed by the processor 451, various data used by the processor 451, and the like. The memory 452, volatile memory such as SRAM and DRAM, or nonvolatile memory such as NAND and MRAM may be used. The storage 453 is a storage device that permanently stores programs, data, and the like, and is, for example, an HDD or an SSD. The controller information storage unit 301 in FIG. 4 can be realized by the memory 452 or the storage 453 or both. Memory or storage may be externally connected to the device.

  The processor 451 reads the program from the storage 453, expands it in the memory 452, and executes it, thereby realizing the controller function. Specifically, the operation of the monitoring control unit 101 and each element inside it, and the operation of the survival confirmation unit 201 and each element inside it are realized.

  FIG. 6 shows a flowchart of the monitoring control process by the monitoring control unit 101.

  The device state acquisition unit 102 communicates with the device 11 via the control network and acquires state information indicating the device state (S101). If it is determined whether the acquisition has succeeded and the acquisition of status information has failed N times or more consecutively (YES in S102), the control network status determination unit 104 determines that the status of the control network is abnormal ( S103). In this case, the monitoring control unit 101 accesses the controller information storage unit 301 and updates the “control network status” field to “abnormal” (if it is originally “abnormal”, it maintains “abnormal”. To do). In addition, when acquisition of status information fails, there may be a case where there is an abnormality in the gateway, device, or in-building network instead of the control network, but here it is assumed that there is an abnormality in the control network.

  If the acquisition of the state information is successful, the control network state determination unit 104 determines that the state of the control network of its own device is normal (S105). The monitoring control unit 101 accesses the controller information storage unit 301 to update the “control network status” field to “normal” (mainly “normal” if it is “normal”).

  The control network delay calculation unit 105 calculates the time (communication delay) required for communication for obtaining the state information (S106). There are various methods for calculating the communication delay, and the method is not limited to a specific method. For example, there is a method of measuring the time from the start of the acquisition of the state information to the acquisition of the state information and setting half of the time as a communication delay. The history of the calculated communication delay value is stored in a storage area such as a memory.

  Further, the control network delay average calculation unit 108 calculates (updates) the average value of the communication delay based on the communication delay calculated in step S106 (S106). The average may be a simple average, a moving average, a weighted moving average, or another average. The monitoring control unit 101 accesses the controller information storage unit 301 and updates the “average delay value of control network” column.

  The control network delay variance calculation unit 109 calculates (updates) the communication delay variance based on the communication delay calculated in step S106 (S106). The monitoring control unit 101 accesses the controller information storage unit 301 and updates the column of “distribution of delay of control network”. The variance may be anything as long as it is an index that can evaluate variation, such as standard deviation.

  When the control value calculation unit 107 is primary, the control value calculation unit 107 calculates a control value for the device 11 based on the device state acquired in step S101, the communication delay (or its average), and the like (S109). Then, the control value transmitting unit 106 transmits a message including the control value calculated by the control value calculating unit 107 to the device 11 via the control network and the gateway 12 (S109). Thereby, the device 11 is feedback-controlled. As will be described later, immediately after the own device becomes the primary, in addition to using the latest device state information held by the own device, the time stamp stored in the control information storage unit is the latest controller. The latest device status information associated with the information may be used, or the latest device status information associated with the primary before the change may be used in the control information storage unit.

  On the other hand, when the self apparatus is non-primary, the abnormality determination unit 103 verifies whether the device is correctly controlled by verifying the transition of the device state (S108). Each controller is configured to perform the same feedback control on a common device. Therefore, each controller can predict how the device state changes if the device is correctly controlled. Therefore, it can be determined whether the control is correctly performed based on the difference between the transition of the actual device state and the expected transition of the device state. As a simple example, when the device is an air conditioner and is maintained at a certain set temperature, it can be determined that the control is not properly performed when the deviation from the set temperature becomes a predetermined value or more. In this case, the set temperature corresponds to an expected device state.

  The abnormality determination unit 103 may perform an alarm operation when determining that the control is not properly performed. For example, alarm information such as an alarm mail may be transmitted to the terminal device M operated by the controller administrator via the survival confirmation network 21. The alarm mail may include the ID of the primary (controller) and identification information of a device that is not properly controlled. The device identification information may be any information that can identify the device, such as the product number, model number, product name, and communication address of the device. Note that there may be a case where there is a problem with the controller and a case where there is a problem with the device as a reason why the device is not controlled correctly. The administrator who received the alarm mail may identify which one has the problem by investigating. As a modification, the alarm signal may be transmitted to the primary controller, and the control on the device 11 may be stopped when the primary controller receives the alarm signal.

  The monitoring control unit 101 waits until the next acquisition timing (S104) and repeats the above-described processing. The next acquisition timing may be after a predetermined time. In this case, status information is acquired from the device at regular intervals. The value of “fixed interval” may be different between the primary and non-primary controllers. The primary needs to acquire the device state at a necessary interval in order to perform control, but the non-primary controller may acquire the device state at a longer interval than the primary. As a result, the communication amount of the control network can be reduced, so that the communication cost can be reduced. In the case of a failover (change of primary), the control quality may be reduced. However, the latest device status acquired by the primary is added to the heartbeat from the primary before the change. The controller that has become primary can control the deterioration of the control quality by performing device control with reference to it. Note that the next acquisition timing (S104) in FIG. 6 may be after a predetermined time, not at a predetermined time, or at a timing at which a predetermined event occurs, for example.

  FIG. 7 shows a flowchart of heartbeat transmission processing by the survival confirmation unit 201. The HB communication unit 202 transmits a heartbeat to all other controllers other than its own device via the survival confirmation network (S201). As an example, the heartbeat includes all or part of information in the controller information storage unit 301. The heartbeat may be transmitted only to a part of all other controllers.

  The ACK communication unit 203 determines the state of the other controller according to the reception status of the ACK from the other controller (S202). More specifically, it is determined whether the other controller is normal or abnormal. Here, an arbitrary one of the other controllers is described as a controller Cx. The number of other controllers is at least 1, and may be 2 or more.

  When controller state determination unit 204 determines that controller Cx is abnormal (YES in S202, S205) and controller Cx is primary (YES in S206), primary determination unit 205 determines the next primary. (S207). As described above, the primary determination method may be determined based on the state of the control network, the communication delay or its dispersion, the average value, and the like. When the primary determination unit 205 determines the next primary, the survival confirmation unit 201 accesses the controller information storage unit 301 and updates the “role” column. The “role” of the controller newly determined as the primary is set to “primary”, and the “role” of the controller that was the primary before the change is set to “non-primary”. When the own device becomes primary, the latest device status information held by the own device may be used for controlling the device, or the time stamp stored in the control information storage unit is the latest controller. The latest device status information associated with the may be used. Or you may utilize the information of the newest apparatus state linked | related with the primary before a change in a control information storage part.

  If the controller state determination unit 204 determines that the controller Cx is normal (NO in S202, S203), it waits until the next acquisition timing (S204), and repeats the above-described processing. If the controller Cx is not the primary in step S206 or if the next primary is determined in step S207, the process waits until the next acquisition timing (S204) and repeats the above-described processing. When the next acquisition timing is after a predetermined time, transmission of heartbeats is repeated at regular intervals. The next acquisition timing is not limited after the predetermined time.

  FIG. 8 shows a flowchart of the operation of heartbeat reception processing by the survival confirmation unit 201.

  When the HB communication unit 202 receives a heartbeat from another controller and succeeds in decoding, the HB communication unit 202 passes information for generating a delivery confirmation response message (ACK) to the ACK communication unit 203 (S301). The ACK communication unit 203 generates an ACK based on the information, and transmits the ACK via the gateway 12 and the survival confirmation network (S302).

  The existence confirmation unit 201 refers to information on other controllers included in the heartbeat. If there is information associated with the new time stamp, the information in the controller information storage unit 301 of the own device is updated based on the information (S303). At this time, if the existence confirmation unit 201 detects that there is a value that has been changed before and after the update other than the time stamp, the HB communication unit 202 is used to immediately store the information in the control information storage unit. You may send a beat. Thereby, the changed information can be quickly shared between controllers.

  After the controller information storage unit 301 is updated, the abnormality determination unit 103 determines whether the difference between the “latest device status” (see FIG. 4) exceeds the threshold for each pair of two controllers. If there is a set, alarm information such as an alarm mail may be transmitted to the manager's terminal device M via the survival confirmation network 21 (S304). This is because at least one controller or device belonging to the set may not be normal when the difference between the “latest device status” for at least one set exceeds the threshold. The ID of each controller belonging to the set exceeding the threshold may be included in the alarm mail. Here, the difference in the “latest device status” is determined for each pair, but when the variance or standard deviation of the “latest device status” is calculated between these controllers and the variance exceeds the threshold, An alarm mail may be sent.

  In the above-described embodiment, when a primary abnormality (failure) is detected, failover is performed (S205 to S207 in FIG. 7). As another form, the communication quality of the primary control network may be determined based on the communication delay of the control network, and when it is determined that the communication quality is poor, the implementation of failover may be determined. The following are some examples of conditions for performing failover in this case.

(1) When the communication delay of the primary control network becomes larger than the threshold, it is determined to perform file over.
(2) It is determined to perform when the dispersion of the communication delay of the primary control network becomes larger than the threshold value.
(3) When the communication delay of the primary control network becomes larger than the communication delay of the control network of any other controller, it is determined to perform failover. Alternatively, when the communication delay difference is equal to or greater than the threshold, it is determined to perform failover.
(4) When the distribution of the communication delay of the primary control network becomes larger than the distribution of the communication delay of the control network of the other controller, it is determined to perform failover. Alternatively, it is determined that failover is performed when the difference in distribution is equal to or greater than a threshold value.

  An operation example in the case of determining to perform failover based on communication delay as in the above (1) to (4) will be described. FIG. 9 shows another example of an operation flowchart of the heartbeat reception process. Steps S301 to S303 are the same as those in FIG.

  In step S401, it is determined whether the communication quality of the primary control network is bad (whether the above failover condition is satisfied). In the case of (1), it is determined whether the communication quality is poor based on the communication delay of the primary control network. In the case of (2), the variance of the communication delay of the primary control network is calculated (updated), and it is determined whether the communication quality is poor based on the variance. In the case of (3), it is determined whether the communication quality is poor based on the communication delays of the primary and non-primary control networks. In the case of (4), the communication delay variances of the primary and non-primary control networks are calculated (updated), and it is determined whether the communication quality is poor based on these variances.

  In step S402, when it is determined in step S401 that the communication quality of the control network is poor, the next primary is determined. The method for determining the next primary is as described above.

  In this embodiment, the controller showed the form which transmits / receives a heartbeat with all the other controllers. However, this is not essential. Each controller may send and receive heartbeats only with some controllers. Thereby, although the operation rate as a controller group falls, the communication amount between controllers can be reduced. However, each controller needs to be able to grasp information of all other controllers (that is, information in the controller information storage unit). Each controller may obtain information on other controllers that do not directly transmit / receive heartbeats via other controllers that can communicate directly. The existence confirmation network 21 may have an arbitrary configuration (topology) as long as such a condition is satisfied.

  FIG. 10A shows a specific example of the survival confirmation network 21 according to the present embodiment. In this configuration, each of all the controllers is connected to some controllers and not connected to other controllers. However, since information on the other controllers can be acquired via the some controllers, as a result, information on all other controllers can be grasped.

  On the other hand, in the configuration shown in FIG. 10B, since the survival confirmation network 21 is divided into two, the information cannot be grasped for some of all other controllers. For example, the controller C2 can acquire information on the controller C1, but cannot acquire information on the controllers C3 and C4. The same can be said for each of the controllers C1, C3, and C4.

  As described above, according to the present embodiment, the information regarding the communication status and control status of the devices held by each controller is shared between the controllers, and a survival confirmation message is sent to each other so that a high operation rate of feedback control is achieved. Failover between controllers can be realized while maintaining

  Therefore, even when each controller is arranged in a cloud computing environment, a feedback control system with a high operation rate can be realized at low cost and flexibility can be improved. For example, if a gateway breaks down, maintenance personnel go out to replace the gateway or purchase a replacement gateway, which increases human costs, but the controller on the cloud is not operating normally. In this case, it is assumed that the controller can be restarted from a terminal device such as an operator or software is often installed (high flexibility), so that the human cost is low. Even if it is necessary to replace the hardware of the controller itself, the number of controllers is assumed to be small compared to the total number of units in each building when gateways are placed in the building. Can be low.

  Further, since it is not necessary to store information on the status of device control in the gateway, the memory capacity and / or CPU performance can be kept low.

  In addition, the controller of each embodiment is realizable also by using a general purpose computer apparatus as basic hardware, for example. That is, it can be realized by causing a processor mounted on the computer apparatus to execute a program. At this time, the controller implements the above program by installing it in the computer device in advance, stores it in various storage media, or distributes the program through a network, and installs this program in the computer device as appropriate. Can be realized. Each storage unit in the controller appropriately uses a memory, a hard disk or a storage medium such as a CD-R, a CD-RW, a DVD-RAM, a DVD-R, or the like incorporated in or externally attached to the computer device. Can be realized.

  The terms used in this embodiment should be interpreted widely. For example, the term “processor” may include general purpose processors, central processing units (CPUs), microprocessors, digital signal processors (DSPs), controllers, microcontrollers, state machines, and the like. In some situations, a “processor” may refer to an application specific integrated circuit, a field programmable gate array (FPGA), a programmable logic circuit (PLD), or the like. “Processor” may refer to a combination of processing devices such as a plurality of microprocessors, a combination of a DSP and a microprocessor, and one or more microprocessors that cooperate with a DSP core.

  As another example, the term “memory” may encompass any electronic component capable of storing electronic information. “Memory” means random access memory (RAM), read only memory (ROM), programmable read only memory (PROM), erasable programmable read only memory (EPROM), electrically erasable PROM (EEPROM), non-volatile It may refer to random access memory (NVRAM), flash memory, magnetic or optical data storage, which can be read by the processor. If the processor reads and / or writes information to the memory, the memory can be said to be in electrical communication with the processor. The memory may be integrated into the processor, which again can be said to be in electrical communication with the processor.

  The term “storage” may also include any device capable of permanently storing data using magnetic, optical, or non-volatile memory. For example, the storage may be an HDD, an optical disk, an SSD, or the like.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. In addition, various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

C1, C2, C3: Controller 21: Survival confirmation network 12: Gateway 11: Device 101: Monitoring visual control unit 102: Device state acquisition unit 103: Abnormality determination unit 104: Control network state determination unit 105: Control network delay Calculation unit 108: Control network delay average calculation unit 109: Control network delay dispersion calculation unit 107: Control value calculation unit 106: Control value transmission unit 201: Survival confirmation unit 202: Heartbeat (HB) communication unit 203: Delivery confirmation Response (ACK) communication unit 204: Controller state determination unit 205: Primary determination unit 301: Controller information storage unit 451: Processor 452: Memory 453: Storage 454: Network interface 455: Network interface 456: Bus

Claims (16)

A device state acquisition unit for acquiring device state information via the first network;
A storage unit that holds information on whether or not it has a first role of controlling the device for each of its own device and another controller;
When the device itself is in the first role, a control unit that controls the device based on the state information of the device;
A measurement unit for measuring first information related to communication quality of the first network;
A first message including the first information is transmitted to the other controller via the second network, and includes second information related to communication quality of the third network between the other controller and the device. A communication unit for receiving a second message via the second network;
A controller state determination unit that determines the state of the other controller by communicating with the other controller via the second network;
A determination unit that determines a controller of the first role from the own apparatus and the other controller based on the state of the other controller and the first information and the second information;
With a controller. The communication unit receives a third message including the state information of the device acquired by the other controller from the other controller via the second network,
The storage unit stores the state information of the device included in the third message in association with the other controller;
When it is determined that the first role is changed from the other controller to its own device, the control unit uses the state information associated with the other controller in the storage unit, and The controller according to claim 1. The communication unit respectively receives third messages including status information and time stamps of the devices acquired by the plurality of other controllers from the plurality of other controllers via the second network,
The storage unit stores the state information of the device acquired by the device state acquisition unit and a time stamp indicating a time when the state information of the device is acquired, and is received from a plurality of the other controllers. Storing the status information and time stamp of the device included in the third message;
When it is determined that the first role is changed from the other controller to the own device, the control unit uses the state information of the device corresponding to the latest time stamp in the storage unit, and The controller according to claim 1, wherein the controller is controlled. The measurement unit measures a communication delay of the first network;
The control unit calculates a control value for the device based on a communication delay of the first network, and transmits the control value to the device via the first network. The controller according to one item. The controller state determination unit determines whether to change the first role based on the communication delay of the controller having the first role among the own device and the other controller or the state of the controller. Item 5. The controller according to any one of Items 1 to 4. The controller according to any one of claims 1 to 5, wherein the determination unit determines a controller to be the first role based on communication delays of the own device and the other controller. The controller according to any one of claims 1 to 6, wherein the device state acquisition unit changes a time interval for acquiring the state information of the device depending on whether the device has the first role. The controller according to any one of claims 1 to 7, wherein the controller state determination unit determines a state of the other controller according to a reception status of a delivery confirmation message for the first message. The controller according to any one of claims 1 to 8, wherein the first message includes status information of the device acquired by the device status acquisition unit. The other controller has a first role;
The controller state determination unit determines whether the other controller is normal or abnormal,
The controller according to any one of claims 1 to 9, wherein the determination unit determines to change the first role from the other controller when the other controller is abnormal. When the communication unit receives the second message from one of the plurality of other controllers, the communication unit obtains the second information from the second message, and determines the other of the plurality of other controllers. The controller according to claim 1, wherein a fourth message including the second information is transmitted to the controller via the second network. The second message includes status information of the device measured by the one controller,
The controller according to claim 11, wherein the fourth message includes status information of the device measured by the one controller. An abnormality determination unit is provided,
The communication unit receives the status information of the device from the other controller via the second network,
The abnormality determination unit is configured to send a warning information to a device designated in advance according to a difference between the device status information acquired by the device status acquisition unit and the device status information received by the communication unit. Outputting the controller according to any one of claims 1 to 12. An abnormality determination unit is provided,
The other controller has the first role;
The communication unit receives, via the second network, the device status information acquired by the other controller from the other controller a plurality of times over time,
The abnormality determination unit outputs alarm information to a predetermined device in accordance with a deviation between a transition of a value indicated by the received state information and a predetermined transition. The controller described. A program for causing a computer to execute,
Obtaining device status information via a first network;
Holding information on whether or not it has a first role of controlling the device in the storage device for each of its own device and other controllers;
If the device itself is in the first role, a control step for controlling the device based on the state information of the device;
Measuring step of measuring first information relating to communication quality of the first network;
Transmitting a first message including the first information to the other controller via a second network;
Receiving, via the second network, a second message including second information relating to communication quality of a third network between the other controller and the device;
Determining the state of the other controller by communicating with the other controller via the second network;
Causing the computer to execute a state of the other controller and a step of determining the controller of the first role from the own apparatus and the other controller based on the first information and the second information. Program for. Comprising first to nth controllers connected to devices via first to nth networks, respectively.
The plurality of controllers are connected to each other via a network different from the first to nth networks,
Each of the first to n-th controllers is
A device state acquisition unit for acquiring state information of the device via the first to nth networks;
A storage unit that holds information for each of the plurality of controllers as to whether or not the device has a first role of controlling the device;
When the device itself has the first role, a control unit that controls the device based on the state information of the device;
A measurement unit for measuring first information related to communication quality of the first to n-th networks;
A second message including the second information on the communication quality of the network between the other controller and the device is transmitted to the other controller via the other network. A communication unit for receiving a message via the another network;
A controller state determination unit that determines the state of the other controller by communicating with the other controller via the other network;
A determination unit that determines the controller of the first role from the first to n-th controllers based on the state of the other controller and the first information and the second information;
Control system with.

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