WO2018083806A1 - Control apparatus, control system and control method - Google Patents

Abstract

A control apparatus comprises a communication unit (320), a determination unit (310B) and a sleep instruction unit (310C). The communication unit uses a multi-hop communication among a plurality of nodes including a connected first node and a un-connected second node, and receives information from the first node. The determination unit determines an acceptance date/time of acceptance by the first node of a connection with the second node, on the basis of the battery level of the first node, communication quality between the first node and the second node, power characteristics of the second node, and first environment information related to the environment of the position where the second node is located. The sleep instruction unit sends an instruction to the first node indicating that the first node should be in sleep state until the acceptance date/time.

Description

Control device, control system, and control method

The present invention relates to a control device, a control system, and a control method.

In recent years, for example, WSNS (Wireless Sensor Network System) that collects sensor nodes (hereinafter simply referred to as nodes) on sensing targets such as cliffs, roads, buildings, etc., and collects the status of the sensing targets through wireless communication via each node. It has been known. The observation device in the WSNS collects the state detected by each node, and recognizes the state of the sensing target based on the collection result.

For example, when each node performs environmental power generation using solar cells, the amount of power stored in the secondary battery of each node changes according to the environment such as the weather. For this reason, each node performs the operation | movement according to the electrical storage amount.

JP 2012-063907 A JP 2013-027164 A JP 2012-080622 A Japanese Patent Laying-Open No. 2015-122572

However, even when the node does not perform the measurement operation, the secondary battery of the node may become empty due to natural discharge or a leakage current of the power supply circuit. Such a node is activated when the power storage environment is ready, and attempts to connect to surrounding nodes. Each node also consumes power during this connection attempt, so the secondary battery of the node runs out at night, and connection attempts cannot be made at night or on bad days.

An object of one aspect is to provide a control device or the like that can efficiently perform connection setting between nodes.

In one plan, the control device includes a communication unit, a determination unit, and a sleep instruction unit. The communication unit receives information from the first node using multi-hop communication between a plurality of nodes including a connected first node and an unconnected second node. The determination unit includes: a remaining battery level of the first node; a communication quality between the first node and the second node; a power characteristic of the second node; and the second node. And the first environment information related to the environment at the position where the node is arranged, the reception date and time at which the first node accepts the connection with the second node is determined. The sleep instruction unit instructs the first node to place the first node in a sleep state until the acceptance date and time.

In one aspect, connection settings between nodes can be performed efficiently.

FIG. 1 is an explanatory diagram illustrating an example of a control system according to this embodiment. FIG. 2 is a diagram illustrating an example of a node. FIG. 3 is a diagram illustrating an example of the control device. FIG. 4 is a block diagram illustrating a functional configuration example of a node. FIG. 5 is a block diagram illustrating a functional configuration example of the control device. FIG. 6 is a flowchart illustrating an example of a processing operation when the node is activated. FIG. 7 is a flowchart illustrating an example of the processing operation in the reception standby state of the node. FIG. 8 is a flowchart illustrating an example of a processing operation in a standby state of the control device. FIG. 9 is a diagram illustrating a configuration example of unconnected node information. FIG. 10 is a diagram illustrating a configuration example of connection node information. FIG. 11 is a flowchart illustrating an example of the update processing operation of the control device. FIG. 12 is a diagram illustrating a configuration example of environment information. FIG. 13 is a diagram for explaining an example of a route selection method. FIG. 14 is a flowchart illustrating an example of the sleep processing operation of the control device. FIG. 15 is a flowchart illustrating an example of a post-acceptance processing operation of the control device.

Hereinafter, embodiments of a control device, a control system, and a control method disclosed in the present application will be described in detail based on the drawings. The disclosed technology is not limited by the present embodiment. Moreover, you may combine suitably each Example shown below in the range which does not cause contradiction.

FIG. 1 is an explanatory diagram showing an example of the control system 1 of the present embodiment. A control system 1 shown in FIG. 1 is a sensor system that collects information measured using a sensor via a network. The control system 1 is composed of, for example, a WSNS (Wireless Sensor Network System), and includes a plurality of nodes 2, a gateway (GW) 3, and the Internet 4. Node 2 and GW 3 are connected by a multi-hop wireless network using multi-hop communication (also called ad hoc communication). The GW 3 of the control system 1 collects information measured by each node 2.

Node 2, which is a sensor node, is dispersed and arranged on a sensing target such as a cliff, a road, or a structure, and detects the state of the sensing target. The node 2 wirelessly communicates with other nodes 2 in the control system 1 using multi-hop communication. Each node 2 has, for example, a parent-child connection relationship and wirelessly communicates with other nodes 2 in a predetermined area by multi-hop communication. In each node 2, a parent node on the upper side and a child node on the lower side are connected to a tree structure.

GW 3 is a communication device that is connected to the node 2 for communication, and is an example of a control device 300 described later. The GW 3 connects to the node 2 using multi-hop communication. The GW 3 is directly connected to the node 2 in the predetermined area, and is connected to the other nodes 2 via one or more nodes 2. The GW 3 is connected to the Internet 4 via a wired or cellular phone network. The GW 3 acquires environment information 5 indicating information regarding the environment of the place where the node 2 is located using the Internet 4, and controls the node 2 using the acquired environment information 5. The GW 3 controls the operation state of the node 2 using the state and characteristics of the node 2. For example, the GW 3 changes the node 2 to a sleep state or a normal operation state. The GW 3 controls the operation state of the node 2 by transmitting the sleep date and time and the start date and time to the node 2. The GW 3 collects information acquired by the node 2 using a sensor or the like via multi-hop communication between the nodes 2, and transmits the collected data to a server or the like via the Internet 4.

In the control system 1 shown in FIG. 1, for example, when the node 2 of “E” and “F” is a child node, the node 2 of “D” is the parent node of “E” and “F”, and “D” If node 2 is a child node, node 2 of “A” is the parent node of “D”. Further, for example, when “G” and “H” node 2 are child nodes, “C” node 2 is “G” and “H” parent node, and “C” node 2 is a child node. In this case, the node 2 of “A” is set as the parent node of “C”. Furthermore, when the node 2 of “I” and “J” is a child node, the node 2 of “B” is the parent node of “I” and “J”. The GW 3 is wirelessly connected to the nodes 2 of “A” and “B”. Further, the GW 3 is connected to the Internet 4 for communication. The GW 3 may be connected to a communication line other than the Internet 4.

FIG. 2 is a diagram illustrating an example of the node 2. FIG. 2 shows a hardware configuration example of the node 2. The node 2 includes an information processing unit 20, an energy harvesting element 21, a power supply control unit 22, and a secondary battery 23. The information processing unit 20 includes an MCU (Micro Controller Unit) 24, a RAM (Random Access Memory) 25, a ROM (Read Only Memory) 26, a sensor 27, and a wireless unit 28.

In node 2, the power supply control unit 22 is connected to the information processing unit 20, the energy harvesting element 21, and the secondary battery 23. In the information processing unit 20, the MCU 24, the RAM 25, the ROM 26, the sensor 27, and the wireless unit 28 are connected by a bus or the like.

The environmental power generation element 21 is, for example, a power generation element such as a vibration power generation element, a photovoltaic power generation element, a temperature power generation element, or a radio wave power generation element. When the environmental power generation element 21 is a power generation element such as a solar battery, the environmental power generation element 21 generates power using sunlight. The environmental power generation element 21 sends the generated power to the power supply control unit 22. The energy harvesting element 21 is also called an energy harvesting element. The secondary battery 23 is, for example, a battery that stores electric power generated by the energy harvesting element 21. The secondary battery 23 may be charged with electric power instead of storing electric power.

The power supply control unit 22 controls the energy harvesting element 21 and the secondary battery 23. The power supply control unit 22 controls the storage and discharge of electric power. The power supply control unit 22 sends the power generated by the energy harvesting element 21 to the information processing unit 20 or stores it in the secondary battery 23. In addition, the power supply control unit 22 sends the power stored in the secondary battery 23 to the information processing unit 20.

The RAM 25 of the power supply control unit 22 stores data used by the MCU 24. The RAM 25 of this embodiment stores information sent from the GW 3 and information acquired by the node 2. Specifically, the RAM 25 stores, as information sent from the GW 3, a standby time or activation time designated by the GW 3. Further, the RAM 25 stores, as information acquired by the node 2, an LQI (radio wave communication quality: Link Quality Indicator) indicating the received radio wave intensity of the received data and a storage amount that is a remaining battery level. The RAM 25 stores the LQI of received data for each ID for identifying the node 2 that is the data transmission source.

ROM 26 stores a program used by MCU 24. The ROM 26 has a parent node table and a child node table. The parent node table is an area for storing an ID for identifying a parent node, for example, a MAC address, as a parent node of the own node 2. The child node table is an area for storing an ID for identifying a child node, for example, a MAC address, as a child node of the own node 2.

Sensor 27 is an element that detects the state of the sensing target. For example, the sensor 27 detects landslides and floods. The sensor 27 sends the detected information to the MCU 24. The wireless unit 28 is a part that performs wireless communication with another node 2 or GW 3 existing within a predetermined wireless range by multi-hop communication. The radio unit 28 performs radio communication with, for example, a parent node on the upstream side of the own node 2 and a child node on the downstream side of the own node 2.

The MCU 24 operates as a microcontroller, and drives the RAM 25, the ROM 26, the sensor 27, and the wireless unit 28. The MCU 24 reads a program stored in the ROM 26 and performs various processes based on the read program. The MCU 24 is activated when the remaining battery level, which is the amount of stored electricity, exceeds a predetermined amount. Further, the MCU 24 controls a start process, a standby process, and the like according to an instruction from the GW 3. Further, the MCU 24 measures LQI, the remaining battery level, and the like, and transmits the measurement result from the wireless unit 28 to the other node 2 or GW 3.

Further, the MCU 24 transmits information detected by the sensor 27 from the wireless unit 28 to the GW 3 side that is the upstream side of communication. As a result, the information detected by the sensor 27 is sent to the GW 3 via one or more nodes 2 or directly.

The node 2 of this embodiment extends the standby time by waiting outside the time period during which connection processing is performed. In other words, the node 2 of this embodiment is activated when performing the connection process, thereby shortening the activation time.

FIG. 3 is a diagram illustrating an example of the control device 300. In FIG. 3, the hardware structural example of control apparatuses 300, such as GW3, is shown. A control device 300 such as a sensor control device has the same configuration as a general PC (Personal Computer) except that a wireless unit 35 that is a short-range wireless communication module is mounted. Specifically, the control device 300 includes a CPU (Central Processing Unit) 31, a RAM 32, an HDD (Hard Disk Drive) 33, a communication adapter 34, and a wireless unit 35. In the control device 300, the CPU 31, RAM 32, HDD 33, communication adapter 34, and wireless unit 35 are connected by a bus or the like. Power is supplied to the control device 300 from the outside by wire. The control device 300 is realized by causing the CPU 31 to execute a program prepared in advance.

The HDD 33 is an example of a computer-readable recording medium. Various programs are stored in the HDD 33 in advance. For example, the HDD 33 stores a connection processing program, a connection processing program, a determination program, a sleep instruction program, an acceptance processing program, and the like. Each program may be recorded in a memory (not shown) which is an example of a computer-readable recording medium instead of the HDD 33. As the recording medium, for example, a portable recording medium such as a CD-ROM, a DVD disk, or a USB memory, or a semiconductor memory such as a flash memory may be used. Further, the HDD 33 of this embodiment stores information sent from the node 2 and information acquired by the control device 300. Specifically, the HDD 33 stores unconnected node information 335A, connected node information 335B, which will be described later, and the like.

The CPU 31 reads out various programs stored in the HDD 33 and performs various processes based on the read out various programs. The CPU 31 reads each program from the HDD 33 and functions on the RAM 32 as a process. The RAM 32 stores data used by the CPU 31.

The communication adapter 34 is connected to the Internet 4 and uses the Internet 4 to acquire the environment information 5 of the location where the node 2 is arranged. The environment information 5 acquired by the communication adapter 34 is stored in the HDD 33 by the CPU 31. Further, the communication adapter 34 transmits information collected by the node 2 (whether or not landslide or flood has occurred) to an external device such as a server using the Internet 4.

The wireless unit 35 is a communication interface that collects information from the node 2 using multi-hop communication between the plurality of nodes 2.

Next, a functional configuration example of the node 2 will be described. FIG. 4 is a block diagram illustrating a functional configuration example of the node 2. The node 2 includes an information processing unit 20, an energy harvesting element 21, a power supply control unit 22, and a secondary battery 23. The information processing unit 20 includes a control unit 210, a communication unit 220, a storage unit 230, and a sensor 27. The communication unit 220 has the function of the wireless unit 28, the control unit 210 has the function of the MCU 24, and the storage unit 230 has the functions of the RAM 25 and the ROM 26.

The communication unit 220 is a communication interface that communicates with the node 2 and the control device 300. The storage unit 230 includes a parent node table 230A, a child node table 230B, and an LQI table 230C. The parent node table 230A is an area for storing, for example, an ID for identifying a parent node viewed from the own node 2 and a MAC address in association with each other. The child node table 230B is an area for storing, for example, an ID for identifying a child node viewed from the own node 2 and a MAC address in association with each other. The LQI table 230C is an area for storing the LQI of received data for each ID for identifying the node 2 that is the data transmission source.

The control unit 210 reads a program stored in the storage unit 230 and executes various processes based on the read program. The control unit 210 includes a calculation unit 210A, an addition unit 210B, and an instruction unit 210C.

When the calculation unit 210A receives data from the child node 2, the calculation unit 210A calculates the LQI. For example, when the electric field strength (dBm) is P, the calculation unit 210A calculates LQI = (20P + 1970) / 7. In addition, the calculation unit 210 </ b> A calculates a storage amount that is the amount of power stored in the secondary battery 23. The adding unit 210B adds the calculated LQI and the charged amount to the transmission data to the control device 300.

The instruction unit 210C generates instruction information and sends the generated instruction information to the communication unit 220. Thereby, the instruction unit 210C gives various instructions to the external apparatus connected to the communication unit 220. For example, the instruction unit 210C instructs the communication unit 220 to transmit data to the control device 300. In addition, the instruction unit 210C instructs the communication unit 220 to transmit a connection request to the parent node 2 when the node 2 is activated. When the instruction unit 210C receives a connection request from the child node 2, the instruction unit 210C instructs the communication unit 220 to transmit a response to the child node 2. In addition, when the connection process with the parent node 2 is successful, the instruction unit 210C instructs the communication unit 220 to transmit a connection completion notification. In addition, the instruction unit 210C instructs the components in the node 2 to change to the power failure power mode, to change to the normal operation mode, to stop the wireless module, to start the wireless module, and the like.

Next, a functional configuration example of the control device 300 such as the GW 3 will be described. FIG. 5 is a block diagram illustrating a functional configuration example of the control device 300. The control device 300 includes a control unit 310, a communication unit 320, and a storage unit 330. The communication unit 320 has functions of the wireless unit 35 and the communication adapter 34. The control unit 310 has the function of the CPU 31. The storage unit 330 has the functions of the RAM 32 and the HDD 33.

The communication unit 320 is a communication interface that communicates with the node 2 and external devices. The storage unit 330 includes an unconnected node information storage unit 330A, a connection node information storage unit 330B, a node state storage unit 330C, and an environment information storage unit 330D. The unconnected node information storage unit 330A is an area for storing unconnected node information generated by the control unit 310. The connection node information storage unit 330B is an area for storing connection node information generated by the control unit 310. The node state storage unit 330C is an area for storing a connection state, an operation state, and the like of the node 2. The environment information storage unit 330 </ b> D stores the environment information 5 acquired by the communication unit 320 using the Internet 4. The environmental information 5 includes environmental performance information about the environment so far and environmental prediction information about the future environment. The environmental performance information and the environmental prediction information are, for example, the amount of sunlight, the temperature, the humidity, or the wind speed.

The control unit 310 reads the program stored in the storage unit 330 and performs various processes based on the read program. The control unit 310 includes a connection processing unit 310A, a determination unit 310B, a sleep instruction unit 310C, and an acceptance processing unit 310D. The connection processing unit 310 </ b> A controls connection processing with the node 2. The determination unit 310 </ b> B updates information regarding the node 2 in the storage unit 330 and determines an acceptance date and time for accepting a connection from another node 2. For example, the determination unit 310B extracts the LQI and the remaining battery level from the data received from the node 2 through the communication unit 320, and updates the LQI and the remaining battery level stored in the storage unit 330. The sleep instruction unit 310C instructs the node 2 to place the node 2 in the sleep state until the reception date and time. The sleep instruction unit 310C according to the present embodiment sleeps until the expected start date and time for the node 2 selected as the path when it can be predicted that sufficient power has been accumulated for connection or relay in all the nodes 2 on the path. Let The sleep instruction unit 310C causes each node 2 to sleep again after the node 2 tries to accept the connection. The acceptance processing unit 310D sets the node 2 that is a connection acceptance target based on the timing at which the unconnected node 2 is activated.

Note that the node 2 may execute various processes using a microcomputer such as a CPU or MPU (Micro Processing Unit) instead of the MCU 24 or together with the MCU 24. The control device 300 may execute various processes using a microcomputer such as an MCU or MPU instead of the CPU 31 or together with the CPU 31.

By the way, for example, in the environmental power generation using solar cells, power generation stops due to snow on the solar panel in winter, but at the same time, the periphery of the node 2 is covered with snow, so depending on the purpose of the measurement, the measurement operation may be performed during this period. Sometimes it is not necessary. For example, in winter, it may not be necessary to measure landslides caused by floods.

When the snow melts in the spring, the power supply from the solar panel begins, but the secondary battery 23 is almost empty due to natural discharge and the leakage current of the power circuit, although it is not measured during the winter. It is assumed that

For this reason, the node 2 starts when a certain amount of power is charged by the solar battery and tries to reconnect to the surrounding nodes 2. For example, in the daytime on a sunny day, the node 2 can try the connection, but the battery runs out at night, and the node 2 runs out at night or in bad weather. It is assumed that a connection attempt cannot be made.

If the connection attempt is started after the secondary battery 23 is fully charged, the connection attempt can be performed for a long time. However, if the capacity of the secondary battery 23 is larger than the power generation amount of the solar battery, it takes a very long time to charge. . Further, in the control system 1, connections are made in order from the node 2 close to the control device 300. For this reason, depending on conditions such as sunlight, when the network extends to the vicinity of the node 2 at the end, the node 2 at the end has exhausted the battery due to the connection attempt and may wait for a long time until the charging is completed again. There is also sex.

On the other hand, power consumption can be reduced by putting the node 2 in a sleep state in which no communication operation is performed, but connection attempts from neighboring nodes 2 cannot be accepted during sleep. Further, the node 2 in the sleep state does not perform the relay operation for multi-hop communication. For this reason, taking these into account, the control device 300 of this embodiment determines the sleep period of the node 2.

Specifically, the control device 300 acquires environmental information 5 such as a weather forecast from the Internet 4 and predicts the date and time when the unconnected node 2 performs a connection attempt based on the weather forecast. Then, the control device 300 controls the sleep of the node 2 so that another connected node 2 occurs in accordance with the predicted date and time. Thereby, it can be expected that the unconnected node 2 can be collected while charging the secondary battery 23. It should be noted that the node 2 starts a connection attempt when the power recovers even a little, and immediately after the connection, the node 2 sleeps from the control device 300 so that it can be controlled from the control device 300 while being charged.

Thereby, even when the node 2 is not sufficiently charged and cannot move for a long time, the connection setting between the nodes 2 can be performed efficiently. In addition, since the node 2 goes to a sleep state at an appropriate timing not only for the sensing operation but also for the communication relay operation, it is possible to efficiently use power even when a plurality of nodes 2 occur simultaneously. It becomes.

Next, the operation flow of the node 2 and the control device 300 will be described. First, an operation flow when the node 2 starts up and an operation flow when the node 2 waits for reception will be described. Subsequently, as an operation flow of the control device 300, an operation flow in a standby state, an operation flow of update processing, an operation flow of sleep processing, and an operation flow of post-acceptance processing will be described.

In the following description, the node 2 that starts and makes a connection request to the parent node or the control device 300 may be referred to as a node 2X or a child node 2X. Further, a parent node that receives a connection request from the node 2X may be referred to as a node 2Y or a parent node 2Y. Therefore, in this embodiment, the node 2X is an unconnected child node, and this node 2X tries to connect to the parent node 2Y. In this embodiment, the node 2Y is a connected parent node, and the node 2Y tries to accept a connection request from the child node 2X. A child node that transmits a connection request to the node 2X may be referred to as a node 2Z or a child node 2Z.

FIG. 6 is a flowchart showing an example of processing operation when the node 2 is activated. In the node 2X that is a wireless sensor node, when the environmental power generation element 21 starts generating power from the state where the secondary battery 23 is empty or nearly empty, the power supply control unit 22 of the node 2X starts charging the secondary battery 23. Specifically, the energy harvesting element 21 of the node 2X starts power feeding to the secondary battery 23 using sunlight or the like (step S11).

When the charging of the secondary battery 23 of the node 2X proceeds and the terminal voltage of the secondary battery 23 exceeds the operating voltage of the MCU 24 to some extent, the power control unit 22 of the node 2X starts supplying power to the control unit 210 that is the MCU 24 To do. Upon receiving power supply, the instruction unit 210C of the node 2X activates the communication unit 220, which is a wireless module (step S12), and causes the communication unit 220 to transmit a connection request to the network. Thereby, the node 2X transmits a connection request to the network to the nearby node 2Y (step S13). The node 2Y to which the connection request to the network is transmitted is the node 2 arranged higher in the tree structure than the node 2X.

After the connection request is transmitted, the instruction unit 210C of the node 2X determines whether or not there is a response from the node 2Y (step S14). When there is no response (No at Step S14), the node 2X waits for a predetermined time (Step S15), and then transmits a connection request to the network to the nearby node 2Y (Step S13). As described above, when there is no response from the node 2Y, the connection request is retransmitted after waiting for a predetermined time.

The node 2X repeats waiting for a certain period of time, sending a connection request, and determining whether or not there is a response until there is a response. The node 2X executes at least transmission of a connection request and determination of presence / absence of a response as processing of one cycle of the connection request. When the power used for one cycle of the connection request exceeds the amount of energy generated by the environmental power generation, the amount of power stored in the secondary battery 23 gradually decreases. When the terminal voltage of the secondary battery 23 falls below the operating voltage of the MCU 24, the power supply control unit 22 stops supplying power to the MCU 24, thereby stopping the operation of the MCU 24. Thereafter, when the capacity of the secondary battery 23 is restored by charging again, the MCU 24 is restarted by power feeding, whereby the processes of steps S11 to S15 are repeated.

If there is a node 2Y connected to the network in a state where the connection with the node 2X can be accepted in the vicinity of the node 2X, the node 2Y returns a response to the connection request to the node 2X. Therefore, when there is a response from the node 2Y to the node 2X (Yes at Step S14), the instruction unit 210C of the node 2X causes the communication unit 220 to execute a connection process with the node 2Y (Step S16). As a result, network connection processing is performed between the nodes 2X and 2Y, and as a result, network connection is established. Note that the state in which the connection is accepted refers to a state in which, for example, the wireless module of the node 2Y is in a reception state, and as a result, a connection request from the node 2X can be received.

After the network connection process between the nodes 2X and 2Y is established, the instruction unit 210C of the node 2X causes the communication unit 220 to transmit a connection notification to the GW 3 that is the control device 300 (step S17). The connection notification is a notification indicating that the network connection processing between the nodes 2X and 2Y has been established. Thereafter, the node 2X transitions to a reception standby state.

FIG. 7 is a flowchart showing an example of the processing operation of the node 2 in the reception standby state. When the node 2Y in the reception standby state receives the sleep instruction from the control device 300, the node 2Y waits in the sleep state for the time specified by the sleep instruction. Specifically, the instruction unit 210C of the node 2Y stops the communication unit 220 that is a wireless module (step S21).

Then, the instruction unit 210C of the node 2Y changes the operation mode of the control unit 210, which is the MCU 24, to a power failure power mode that operates with lower power than the normal operation mode (step S22). The power failure mode is an operation mode in which the MCU 24 is in a sleep state. In the sleep state, the communication unit 220 does not perform wireless transmission / reception processing, and the MCU 24 also stands by in a low power consumption state. Therefore, power consumption can be greatly reduced, and the secondary battery 23 can be dedicated to the recovery. On the other hand, in the sleep state, since the communication unit 220 of the node 2Y does not perform wireless transmission / reception, even if the nearby node 2X transmits a connection request, it cannot respond.

After the node 2Y transitions to the power failure power mode, the instruction unit 210C of the node 2Y waits until the designated time designated by the sleep instruction (step S23). When waiting for the designated time is completed, the instruction unit 210C of the node 2Y changes the operation mode of the control unit 210, which is the MCU 24, to a normal operation mode that operates with power larger than the power failure power mode (step S24). Further, the instruction unit 210C of the node 2Y activates the communication unit 220, which is a wireless module (step S25), and then enters a reception standby state.

When the node 2Y in the reception standby state receives a connection request from the child node 2X, the instruction unit 210C of the node 2Y causes the communication unit 220 to transmit a connection response to the node 2X (step S26). Thereby, the network connection process between the nodes 2X and 2Y is established. Thereafter, the node 2Y enters a reception standby state.

Even when the node 2X receives a connection request from the child node 2Z, the instruction unit 210C of the node 2X causes the communication unit 220 to transmit a connection response to the node 2Z. Thereby, the network connection process between the nodes 2X and 2Z is established. Thereafter, the node 2X enters a reception standby state.

Further, when the node 2Y in the reception standby state receives the state measurement instruction from the control device 300, the node 2Y measures the data instructed by the state measurement instruction (step S27). The state measurement instruction from the control device 300 includes an instruction to measure the LQI of the node 2Y and an instruction to measure the remaining battery level of the node 2Y. The calculation unit 210A of the node 2Y calculates the LQI for each nearby node 2 as the state measurement. Further, the calculation unit 210A of the node 2Y calculates the remaining battery level of the node 2Y as the state measurement. The communication unit 220 transmits the calculated LQI and the remaining battery level to the control device 300 in accordance with an instruction from the instruction unit 210C. The communication unit 220 of the node 2Y transmits the LQI and the remaining battery level to the node 2Y that is the parent node or the control device 300. Thereby, the LQI and the remaining battery level are transmitted to the control device 300 directly or via one to a plurality of nodes 2 (step S28). Thereafter, the node 2Y enters a reception standby state.

FIG. 8 is a flowchart showing an example of the processing operation of the control device 300 in the standby state. In the control device 300 in the standby state, when the communication unit 320 receives a connection request from the child node 2, the connection processing unit 310A transmits a connection response to the node 2 (step S31). And the control apparatus 300 will be in a standby state.

Further, since the control device 300 in the standby state is externally powered, it can always be in a reception state, that is, a state in which a connection request can be accepted. Therefore, the node 2 in the vicinity of the control device 300, that is, a place where direct communication is possible, can be connected to the control device 300 immediately after activation.

In the control device 300 in the standby state, when the communication unit 320 receives a connection notification indicating the completion of the connection between the nodes 2X and 2Y from the node 2X, the connection processing unit 310A connects the child node 2X that is the transmission source node. It is recorded as a state node (step S32). In this case, when the new node 2 is connected, the control device 300 collects and records the current remaining battery level of the connected node 2 and the like. Specifically, the connection processing unit 310A registers the entry of the child node 2X, the remaining battery level of the child node 2X, and the like in the connected node information 335B in the connection node information storage unit 330B. Further, the connection processing unit 310A deletes the entry of the child node 2X from the unconnected node information 335A in the unconnected node information storage unit 330A. Furthermore, the control device 300 transmits a sleep instruction up to the next update date and time to the child node 2X that is the transmission source node (step S33). And the control apparatus 300 will be in a standby state. Even when the node 2Z is a child node, the node 2Z performs the same processing as the node 2X.

Further, in the control device 300 in the standby state, the determination unit 310B starts preparation for update processing of the unconnected node information 335A and the connected node information 335B immediately before the update date and time for updating the sleep state setting and the like. When preparation is complete, update processing is performed. The determination unit 310B may periodically set the update date and time for executing the update process at an arbitrary time interval such as 12 hours or 24 hours, or in the morning and noon in consideration of the characteristics of energy harvesting. It may be set at an arbitrary timing.

FIG. 9 is a diagram illustrating a configuration example of the unconnected node information 335A. The unconnected node information 335A includes a node ID for identifying the node 2, an LQI, a correlation coefficient (α _n ), an estimated previous stop date / time (t ′ _ne ), an estimated start date / time (t _n ), This information is associated with the connection acceptance time.

LQI is the communication quality with other nodes 2 and is registered in the unconnected node information 335A for each other node 2. The correlation coefficient is a coefficient for predicting the power generation amount of the unconnected node 2X, and is a coefficient corresponding to the correlation between the environmental information 5 and the power generation amount. The correlation coefficient corresponds to the power characteristic of the node 2X. The estimated previous stop date and time is the date and time when the node 2X is estimated to have stopped last time.

Since the node 2X operates to reduce the amount of stored electricity, the node 2X stops when a time corresponding to the amount of stored power and operating power elapses. Therefore, the determination unit 310B calculates the estimated previous stop date and time based on the amount of stored electricity, the operating power, and the like. The estimated activation date / time is the date / time when the node 2 is estimated to be activated. In the unconnected node information 335A, the estimated activation date and time of the unconnected node 2X is registered. The node 2 is restarted when the capacity of the secondary battery 23 is recovered by charging. Therefore, the determination unit 310B calculates the estimated startup date and time based on the transition of the amount of stored electricity. The connection acceptance time is a processing time for the node 2 to accept a connection from another activated node 2. In other words, the connection acceptance time is a period set in the node 2 and a period of connection acceptance from the other nodes 2. Therefore, the determination unit 310B calculates the connection acceptance time based on the processing time for one cycle when the connection attempt is made and the number of cycles.

FIG. 10 is a diagram illustrating a configuration example of the connected node information 335B. The connected node information 335B includes a node ID for identifying the GW 3 or the node 2 that is the control device 300, an LQI, a remaining battery level (P _n ) [mWh], a correlation coefficient (α _n ), This is information in which the start date / time (t _n ) is associated with the neighborhood exclusion node. In the connected node information 335B, the LQI and correlation coefficient of the connected node 2Y are registered. In addition, regarding the control apparatus 300, since electric power is supplied from the outside by wire, the remaining battery level and the correlation coefficient are not registered. Further, regarding the control device 300, the node 2 that is the parent node does not exist, so the neighborhood excluded node is not registered.

The battery remaining amount is the remaining amount of power stored in the secondary battery 23 of the node 2Y. The remaining battery level is acquired from the node 2Y and registered in the connected node information 335B. The halfway start date and time is the date and time when the control device 300 or the node 2Y starts during the sleep state. In other words, the mid-starting date and time is an acceptance date and time when the control device 300 or the node 2Y accepts a connection from the child node 2X. The determination unit 310B calculates the mid-starting date and time based on the LQI, the remaining battery level, and the like. The neighborhood exclusion node is a node 2 that is excluded as a child node 2X among the unconnected nodes 2X arranged in the vicinity of the node 2Y. When the connection between the node 2X that is the connection acceptance target and the control device 300 fails, the determination unit 310B registers the node 2X that is the connection acceptance target in the neighborhood exclusion node.

The determination unit 310B collects the unconnected node information 335A based on the LQI before stopping the node 2 and records it in the storage unit 330. After the connection with the node 2, the determination unit 310B displays the connected node 2 as an unconnected node. Delete from the information 335A. Then, the determination unit 310B creates connected node information 335B from information collected after connection.

FIG. 11 is a flowchart showing an example of the update processing operation of the control device 300. The control device 300 acquires the environment information 5 immediately before the update date (step S41). Specifically, the control device 300 obtains the environmental performance information of the node 2 and the environmental prediction information of the node 2 from the Internet 4 a predetermined time before the update date and time. The environmental information 5 is, for example, the amount of sunlight when energy harvesting uses solar cells, and the wind speed when wind power is used. After acquiring the environment information 5, the control device 300 waits until the update date and time (step S42).

When the update date / time is reached, the sleep state of all the connected nodes 2 is canceled, so that the control device 300 can communicate with all the connected nodes 2. Thereby, the determination unit 310B of the control device 300 communicates with the connected node 2, and causes the node 2 to measure the current storage amount and the communication quality between the control device 300 or the surrounding nodes 2. . Then, the determination unit 310B collects the measurement results from the node 2 and records them in the storage unit 330. Specifically, the determination unit 310B transmits an LQI acquisition request to all connected nodes 2 (step S43). Then, the determination unit 310B registers the LQI acquired from the node 2 in the connected node information 335B, thereby updating the LQI (step S44). Further, the determination unit 310B transmits a battery remaining amount acquisition request to all connected nodes 2 (step S45). Then, the determination unit 310B registers the remaining battery level acquired from the node 2 in the connected node information 335B. Note that either the process of step S43 or the process of step S45 may be performed first or simultaneously.

When the determination unit 310B completes the collection of the remaining battery level as the storage amount and the LQI as the communication quality, the correlation coefficient between the environmental information 5 and the generation amount for predicting the generation amount of the connected node 2 And the correlation coefficient in the connected node information 335B is updated (step S46). When updating the correlation coefficient, the determination unit 310B obtains the current storage amount (P _n1 ) and the storage amount (P _n2 ) at the previous measurement from the node 2. The determination unit 310B updates the remaining battery level (P _n ) of the node 2 that is the current charged amount (P _n1 ) in the connected node information 335B (step S47).

The environment information 5 such as the amount of sunlight and wind speed that can be obtained from the Internet 4 is uniform over a wide range. However, since the sunlight and wind perception vary depending on the installation conditions of the node 2, the determining unit 310B sets the correlation coefficient to the node Set individually.

The determination unit 310B calculates the correlation coefficient (α _n ) at the n-th (n is a natural number) node 2 using, for example, the following equation (1). That is, the determination unit 310B determines the ideal power generation amount (E _I ), the current power storage amount (P _n1 ), the power storage amount at the previous measurement (P _n2 ), and the power consumption per unit time during sleep (W _s ) And the elapsed time (t) from the previous measurement, the correlation coefficient (α _n ) is calculated. The ideal power generation amount (E _I ) in the equation (1) is calculated based on the environmental information 5 and the design information of the environmental power generation element 21.

The determination unit 310B calculates the correlation coefficient (α _n ) for all connected nodes 2 and records it in the connected node information 335B. Here, the configuration of the environment information 5 will be described. FIG. 12 is a diagram illustrating a configuration example of the environment information 5330D. Here, a case will be described in which the environment information 5330D is configured to include environment performance information and environment prediction information. The environment information 5330D is information in which a region, a date, a time, a measured value of the amount of sunlight, and a predicted value of the amount of sunlight are associated with each other.

The area is a place where the node 2 is arranged, and is a target area for which the environment information 5330D is set. The date is the date when the amount of sunshine in the environment information 5330D is acquired, and the time is the time when the amount of sunshine in the environment information 5330D is acquired. Moreover, the actual value of the amount of sunshine is a result of the amount of sunshine actually measured in the area in the environment information 5330D. Moreover, the predicted value of the amount of sunshine is the amount of sunshine predicted in the future in the area of the environment information 5330D. The actually measured value of the amount of sunshine is measured using an actual measuring device or the like, and the determination unit 310B acquires the actually measured value using the Internet 4. Moreover, the predicted value of the amount of sunshine is derived from a weather forecast or the like, and the determination unit 310 </ b> B acquires the predicted value using the Internet 4. The environmental performance information is information in which the region, the date, the time, and the measured value of the amount of sunlight are associated with each other in the environmental information 5330D. The environment prediction information is information in which the region, the date, the time, and the predicted value of the amount of sunlight are associated with each other in the environment information 5330D.

For example, it is assumed that a record of the sunshine amount (L _i ) of the target district every hour is distributed as the environment information 5330D via the Internet 4. In this case, the determination unit 310B determines the power generation amount per unit time (W (L _i) from the relationship between the illuminance obtained from the design information of the solar panel that is an example of the energy harvesting element 21 and the power generation amount. )) Can be obtained. Therefore, the determination unit 310B can obtain the ideal power generation amount (E _I ) by integrating the power generation amount per unit time from the previous measurement date and time to the current date and time. Specifically, the determination unit 310B calculates an ideal power generation amount (E _I ) using the following equation (2).

When the information update of the connected node 2 is completed, the determination unit 310B extracts the unconnected node 2 in the vicinity of the connected node 2. In other words, when the update of the connected node information 335B and the environment information 5330D is completed, the determination unit 310B extracts the node 2 in the vicinity of the connected node 2 from the unconnected nodes 2 (Step S48). In this case, in order to extract the node 2, the determination unit 310B acquires the communication quality between the nodes 2 and records it in the connected node information 335B before the node 2 stops because the environmental power generation cannot be performed. deep. For example, the determination unit 310B acquires the communication quality from each node 2 before snow begins. Based on this connected node information 335B, the determination unit 310B extracts the unconnected node 2 whose communication quality with the connected node 2 is greater than or equal to the threshold value for both transmission and reception as the unconnected nearby node 2. .

Next, the determination unit 310B estimates the date and time when each of the extracted unconnected neighboring nodes 2 is activated by energy harvesting and performs a connection trial operation. In other words, the determination unit 310B calculates the estimated activation date / time of the extracted node 2 (step S49). For this calculation, the correlation coefficient of each node 2 is used, but the determination unit 310B uses the above-described method using the equation (1) or the like for the unconnected node 2 before the node 2 stops. Then, the correlation coefficient of the unconnected node 2 is calculated and recorded. Then, the determination unit 310B uses the recorded correlation coefficient of the unconnected node 2. The determination unit 310B predicts the storage amount of the node 2 in each time interval from the correlation coefficient, environmental performance information, and environmental prediction information. Then, the determination unit 310B predicts that the date and time when the predicted power storage amount exceeds the power amount necessary for the operation of the node 2 is the date and time when the node 2 can be started and a connection attempt can be started. The date and time predicted to start this connection attempt is the expected start date and time at which the node 2 can start and start the connection attempt.

When node 2 starts a connection attempt, the power consumption increases greatly, the remaining battery level gradually decreases, and when the storage amount is depleted, node 2 stops its operation and the connection attempt ends. If the period from the estimated start date / time of the connection attempt to the estimated end date / time of the connection attempt is longer than the period required for accepting the connection of the node 2, the determining unit 310B estimates that the node 2 will perform the connection attempt.

The power generation amount per unit time of each node 2 is a value obtained by multiplying the ideal power generation amount W (L _i ) obtained from the environment information 5 and design information of the energy harvesting element 21 by the correlation coefficient α. When the previous connection attempt is completed, the remaining amount of the secondary battery 23 should be exhausted. Therefore, if the date and time when the previous connection attempt is predicted to be _t'ne , the storage of the node n at the time and date t The amount P _n can be calculated using the following formula (3), where W _l is the power consumption that is the amount of discharge due to leakage or the like. Therefore, the determination unit 310B calculates the storage amount P _n using the following equation (3).

The date and time when the charged amount (P _n ) of Equation (3) exceeds the operable threshold (P _t ) is the expected connection start date and time t _ns . On the other hand, during the connection attempt to increase power consumption W _c, quantity of stored power in the time t (t> t _ns) it can be calculated using the following equation (4). Therefore, the determination unit 310B calculates the storage amount P _n using the following equation (4).

The date and time when P _{n in} Equation (4) becomes 0 is the connection trial end date and time t _ne . If the determination unit 310B predicts that the unconnected node 2 will perform a connection attempt, the determination unit 310B indicates the connection acceptance start date and time when connection acceptance is performed between the date and time when the connection acceptance is predicted to start and the date and time when the connection acceptance is predicted to end. Estimated start date and time. The period necessary for accepting the connection is, for example, a length of several cycles of the connection trial period. When the period for the connection attempt to the node n and p _n, estimated start time (t _n) can be calculated from the following equation (5). Therefore, the determination unit 310B calculates the estimated activation date and time (t _n ) using the following equation (5).

The determination unit 310B selects the earliest unselected estimated activation date / time (ti: node i) (step S50). In other words, determination section 310B selects the earliest time ti of the estimated start time t _n of the nodes of the plurality of unconnected 2. Here, a case where the earliest date / time of the estimated activation date / time t _n is date / time t ₁ will be described.

Determination unit 310B, the time ti can be selected, and the date and time t ₁ is determined whether the next update date and time previously (step S51). When the date and time ti cannot be selected (No at Step S51), the control device 300 transitions to a sleep process for the node 2. In addition, if it is later than the date and time t ₁ is the next update date and time (step S51: No), the determining section 310B determines that this time does not perform the acceptance. Then, the process transits to the sleep process for the node 2.

On the other hand, if it is before time t ₁ than the next update date and time (step S51: Yes), the determining unit 310B determines the connection acceptance by the node 2 by corresponding to time t ₁ selected. Then, the determination unit 310B estimates the power storage amount P _n ′ of the connected node 2 at the date and time ti (t1) (step S52). The storage amount P _n ′ is the current storage amount P _n measured at each node 2 as described above, the correlation coefficient α _n calculated from the storage amount P _n , and the sunshine amount (L _i in the environmental prediction information). ) And the power consumption W _s during sleep can be calculated. Therefore, the determination unit 310B calculates the storage amount P _n ′ using the following equation (6). The current power storage amount P _n is calculated using the above-described formula (3) or formula (4).

In addition, after calculating the storage amount P _n ′ of each node 2, the determination unit 310B determines the node 2 that performs relay between the node i that has been determined to accept the connection and the control device 300. At this time, the determination unit 310B determines one to a plurality of nodes 2 corresponding to the route from the node i determined to accept the connection to the control device 300. Thereby, the determination unit 310B searches for all routes from the node i determined to accept the connection to the control device 300. Thus, the determination unit 310B selects a route to the node i determined to accept the connection (step S53).

Since there are various methods for route search, an example will be described here. The determination unit 310B extracts all the routes that reach the control device 300 by tracing the node 2 that has been connected in the vicinity of the unselected node i determined to accept the connection and whose communication quality exceeds the threshold value with a single stroke. To do. Then, the determination unit 310B determines whether or not the route to the node i can be selected (step S54).

If the determination unit 310B determines that the route to the node i cannot be selected (No at step S54), the determination unit 310B repeats the processing of steps S50 to S54 until it is determined that the route to the node i cannot be selected.

The determination unit 310B determines that the path is acceptable if the power storage amount of all the nodes 2 on the path exceeds the power necessary for connection acceptance for each path (Yes in step S54). The determination unit 310B selects a route to the node i determined to accept the connection from among the acceptable routes.

During acceptance of connection to become node 2 also all be node 2 for relaying reception standby state in the receiving, multiplied by acceptance period p _n to the power consumption W _R in a reception standby state is power consumption. The power consumption amount in the reception standby state may be smaller than the expected power storage amount.

When there are a large number of connected nodes, there is a possibility that a plurality of routes may be accepted. In this case, the determination unit 310B preferentially selects a route with a small number of relays to the control device 300, for example. Further, if the number of relays is the same, the determination unit 310B compares the nodes 2 having the smallest predicted power storage amount among the routes and selects the route having the larger predicted power storage amount. The determination unit 310B selects one route by weighting with the number of relays of the node 2, the expected power storage amount, the correlation coefficient, or the like.

FIG. 13 is a diagram for explaining an example of a route selection method. For example, there are five nodes 2 from “K” to “O” in the control system 1, and the nodes 2 of “K”, “L”, and “M” are currently connected, and “N”, “O”. Node 2 is not connected. In this case, if the arrows in FIG. 12 represent the proximity relationship between the respective nodes, “O” → “L” → control device 300, “O” → “L” for node 2 of “O”. There are paths of “→” K ”→ control device 300,“ O ”→“ M ”→“ L ”,“ O ”→“ M ”→“ L ”→“ K ”→ control device 300.

For example, if the predicted power storage amount of the node 2 of “K” and “L” exceeds the required power amount but does not exceed the node 2 of “M”, the acceptable path is “O” → “ L ”→ control device 300,“ O ”→“ L ”→“ K ”→ control device 300. The determination unit 310B selects the route of “O” → “L” → the control device 300 having the smallest number of hops among the two routes.

Determination unit 310B, once the route can be selected to record that starts with the time t ₁ to the node 2 on the path. Specifically, the determination unit 310B adds the date and time t ₁ to the midway activation date and time stored in the node 2 on the route and the GW 3 that is the control device 300 (step S55). Then, the determination unit 310B repeats the processes of steps S50 to S55 until there are no more selectable routes. For example, determination unit 310B After storing the midway start date and time node 2 date t _1, with respect to earlier estimated start time t ₂ of the node 2 to the next time t ₁ of time t ₁ node 2 the same Process. However, with respect to node 2 selected as the route date t _1, in order to consume the power of W _R × p _n by waiting, determining unit 310B, when predicting the charged amount, the power fraction for the consumption Calculate by subtracting. Thereafter, the determination unit 310B performs the same processing for all the unconnected nodes 2 whose estimated activation date and time is earlier than the next update date and time. As a result, the halfway start date and time up to the next update date and time is recorded in the node 2 and the connected node information 335B, so that the sleep instruction unit 310C of the control device 300 allows the halfway start date and time in the connected node information 335B. Based on the above, a sleep instruction is given to the node 2.

FIG. 14 is a flowchart showing an example of the sleep processing operation of the control device 300. If the sleep instruction unit 310C of the control device 300 records the start date / time in the middle of each node 2, each start date / time is recorded so that the node 2 starts at the earliest date / time. A sleep instruction is transmitted to the node 2. In addition, the sleep instruction unit 310C transmits a sleep instruction to the node 2 for which the activation date / time is not recorded so as to sleep until the next update date / time.

Hereinafter, a specific instruction procedure for the sleep process will be described. The sleep instruction unit 310C sequentially selects the unselected connected nodes 2. Here, the sleep instruction unit 310C selects one connected unselected node 2 (step S61). Then, the sleep instruction unit 310C confirms whether or not the node 2 can be selected (step S62). When the selection is possible (Yes at Step S62), the sleep instruction unit 310C acquires the shortest halfway start date and time of the selected node 2 from the connected node information 335B (Step S63). Then, the sleep instruction unit 310C confirms whether or not the shortest start date / time can be acquired (step S64). If acquisition is possible (Yes in step S64), the sleep instruction unit 310C transmits a sleep instruction instructing to sleep until the acquired halfway start date and time to the selected node 2 (step S65). On the other hand, if acquisition of the activation date / time is not possible (No at Step S64), the sleep instruction unit 310C transmits a sleep instruction instructing to sleep until the next update date / time to the selected node 2 (Step S66). ). After transmitting the sleep instruction up to the start date and time or the sleep instruction up to the next update date and time to the node 2, the sleep instruction unit 310C repeats the processes of steps S61 to S66.

When the node 2 cannot be selected in the process of step S62 (No in step S62), the reception processing unit 310D acquires the shortest halfway start date and time of the GW 3 that is the control device 300 from the connected node information 335B. (Step S67). In other words, when the sleep instruction is completed for all the nodes 2, the acceptance processing unit 310 </ b> D acquires the date and time when the control device 300 is activated. The start date and time of the control device 300 is a date and time for the control device 300 to issue a sleep instruction again to the node 2 that has executed the connection acceptance process. The acceptance processing unit 310D confirms whether or not the halfway start date and time can be acquired when trying to obtain the halfway start date and time (step S68). If acquisition of the activation date / time is not possible (No at Step S68), the acceptance processing unit 310D causes the control device 300 to enter a standby state. On the other hand, if it can be acquired (Yes at Step S68), the reception processing unit 310D sets the unconnected node 2 having the acquired startup date / time as the estimated startup date / time as the reception target (Step S69).

Furthermore, the acceptance processing unit 310D acquires the connection acceptance time of the node 2 to be accepted (step S70). Then, the acceptance processing unit 310D causes the control device 300 to be in a standby state for the halfway start date / time + connection acceptance time (step S71). Thereafter, control device 300 performs post-acceptance processing.

Each node 2 sleeps for a time instructed by the control device 300, and then starts up and enters a reception standby state. At this time, if a connection request comes to any one of the nodes 2, the node 2 accepts the connection in response to the connection request. Then, the connected node 2 transmits a connection notification to the control device 300 via the other active node 2. In the control device 300, when the node 2 enters the connection acceptance state, the acceptance processing unit 310D executes post-acceptance processing.

FIG. 15 is a flowchart showing an example of the post-acceptance processing operation of the control device 300. Of the processes shown in FIG. 15, the same processes as those described in FIG. 14 may be omitted.

The sleep instruction unit 310C sequentially selects the unselected connected nodes 2. Here, the sleep instruction unit 310C selects one connected node 2 that has not been selected (step S81). Then, the sleep instruction unit 310C confirms whether the node 2 can be selected (step S82). When the selection is possible (Yes at Step S82), the sleep instruction unit 310C compares the start date / time of the selected node 2 with the estimated start date / time of the node 2 to be accepted based on the connected node information 335B. (Step S83). Then, the sleep instruction unit 310C determines whether there is a match between the halfway activation date and time of the selected node 2 and the estimated activation date and time of the node 2 that is the reception target. In other words, the sleep instruction unit 310C determines whether or not the selected node 2 is currently operating (step S84).

If there is no match between the start date / time of the selected node 2 and the estimated start date / time of the node 2 to be accepted (No at step S84), the sleep instruction unit 310C determines that the selected node 2 Judge that it is not working. Since the sleep instruction unit 310C does not need a sleep instruction for the node 2 that is not operating, the sleep instruction unit 310C returns to the process of step S81. On the other hand, if there is a match between the start date / time of the selected node 2 and the estimated start date / time of the node 2 to be accepted (Yes at step S84), the sleep instruction unit 310C An early start date and time is acquired from the connected node information 335B (step S85). Then, the sleep instruction unit 310C confirms whether or not it is possible to acquire the next early start date and time after the present (step S86). If it can be acquired (Yes at Step S86), the sleep instruction unit 310C transmits the acquired sleep instruction up to the mid-start-up date and time to the selected node 2 (Step S87). As described above, the sleep instructing unit 310C is the node activated at that time after the standby time p ₁ which is the response completion time between the earliest activation date / time t _{1 of} all the nodes 2 and the child node 2 2 transmits a sleep instruction until the next halfway start date and time.

On the other hand, when it is impossible to acquire the start date / time during the process (No at Step S86), the sleep instruction unit 310C transmits the sleep instruction up to the next update date / time to the selected node 2 (Step S88). After transmitting the sleep instruction up to the start date and time or the sleep instruction up to the next update date and time to the node 2, the reception processing unit 310D repeats the processes of steps S81 to S88.

When the node 2 cannot be selected in the process of step S82 (No in step S82), the reception processing unit 310D may be the node 2 set as the connection reception target (hereinafter referred to as the reception target node 2). It is determined whether or not the connection has been established (step S89). Thereby, the acceptance processing unit 310D confirms whether or not the expected node 2 is connected.

If not connected (No at Step S89), the acceptance processing unit 310D estimates that the communication state and the power generation environment have changed, and corrects the prediction. Specifically, the acceptance processing unit 310D searches for an active connected node 2 in the vicinity of the acceptance target node 2 (step S90). Then, the acceptance processing unit 310D sets the connected node 2 that has been waiting from the acceptance target node 2 as a neighborhood excluded node, and records it in the connected node information 335B (step S91). The neighborhood exclusion node is arranged in the vicinity of the acceptance target node 2 and operates and waits from the acceptance target node 2, but has not been able to successfully connect the acceptance target node 2 and the control device 300. 2. In this way, the acceptance processing unit 310D, for example, marks the node 2 that has waited for the connection of the acceptance target node 2 to be excluded from the neighboring nodes 2 when the prediction is corrected. 2. Try to connect from 2.

The acceptance processing unit 310D searches for all connected nodes 2 operating in the vicinity of the acceptance target node 2 (step S92). Then, the acceptance processing unit 310D determines whether or not all of the searched connected nodes 2 are set as neighboring exclusion nodes for the acceptance target node 2. In other words, the acceptance processing unit 310D determines whether or not all the searched connected nodes 2 are excluded from the nodes 2 in the vicinity of the acceptance target node 2 (step S93).

If all the connected nodes 2 that have been searched for are excluded from the nodes 2 in the vicinity of the reception target node 2 (Yes in step S93), the reception processing unit 310D determines that all the connected nodes that have been searched The node 2 is deleted from the neighborhood exclusion node to increase the connection acceptance time of the acceptance target node 2 (step S94). In other words, the acceptance processing unit 310D cancels the exclusion mark when the node 2 near the acceptance target node 2 disappears as a result of setting the searched connected node 2 as the neighborhood exclusion node, and connects Increase acceptance time by one to several cycles. The acceptance processing unit 310D sets a process for increasing the connection acceptance time, a process for newly trying to connect to the acceptance target node 2, and a nearby node 2 that has waited for connection when the connection cannot be established as a neighbor exclusion node. Once set, the process is repeated. As a result, the control device 300 can cope with a case where the power generation amount or the communication environment changes.

When the control device 300 is able to connect to the acceptance target node 2 (Yes at Step S89), the acceptance processing unit 310D acquires the next halfway start date and time of the GW 3 that is the control device 300 (Step S95). In the case of negative in step S93 or after step S94, if the control device 300 can connect to the reception target node 2, the reception processing unit 310D acquires the next halfway start date and time of the GW 3 that is the control device 300 (step S95).

Then, the acceptance processing unit 310D confirms whether or not the next halfway start date and time can be acquired (step S96). When acquisition is impossible (No at Step S96), the reception processing unit 310D causes the control device 300 to enter a standby state. On the other hand, if acquisition is possible (Yes at step S96), the reception processing unit 310D sets the unconnected node 2 having the acquired startup date / time as the estimated startup date / time as an acceptance target (step S97). Further, the acceptance processing unit 310D acquires the connection acceptance time of the acceptance target node 2 (step S98). Then, the acceptance processing unit 310D causes the control device 300 to be in a standby state for the halfway start date / time + connection acceptance time (step S99). Thereafter, control device 300 performs post-acceptance processing. As described above, the determination unit 310B is based on the remaining battery level of the node 2Y, the LQI between the nodes 2X and 2Y, the correlation coefficient of the node 2X, and the environment information 5 at the position where the node 2X is disposed. The node 2Y determines a connection acceptance date and time for accepting a connection with the node 2X. Then, the sleep instruction unit 310C instructs the node 2Y to set the node 2Y to the sleep state until the connection acceptance date and time.

When the next update date and time is reached, the control device 300 is in a state where all of the devices including the newly connected node 2 are activated. For this reason, the control device 300 repeats the same processing as described above for the active node 2, and increases the number of nodes 2 to be connected while recovering the secondary battery 23 by sleep.

With the above-described processing, it is possible to suppress the time or the number of nodes that are activated to accept the connection of the unconnected node 2X. Therefore, it is possible to recover the storage amount by sleeping while accepting the unconnected node 2X. .

When the node 2 receives the sleep instruction from the control device 300 until the reception date and time, the node 2 enters the sleep state until the reception date and time. As a result, each node 2 can enter the sleep state until the reception date and time in accordance with the sleep instruction from the control device 300.

Since each node 2 can be in a sleep state until the date and time of acceptance, the amount of stored electricity can be increased. As a result, the control device 300 can efficiently perform connection setting between the nodes 2.

Based on the remaining battery level of the connected node 2Y, the LQI between the nodes 2X and 2Y, the correlation coefficient that is the power characteristic of the node 2X, and the environment information 5 of the node 2X, the determination unit 310B Determines the connection acceptance time for accepting the connection of the node 2X. As a result, the control device 300 can cause the node 2Y to sleep until the node 2X is activated.

The sleep instruction unit 310C causes the node 2 that is not connected to the communication path from the control device 300 to the node 2Y to enter a sleep state. As a result, the control device 300 can increase the amount of power stored in the node 2Y that is not connected to the communication path to the node 2Y.

The determining unit 310B calculates the estimated activation date / time of the node 2X based on the prediction result of the remaining battery level of the node 2X, and determines the acceptance date / time that is the mid-term activation date / time of the node 2Y using the estimated activation date / time. As a result, the control device 300 can activate the node 2Y at an accurate timing according to the activation of the node 2X.

The acceptance processing unit 310D sets the node 2X as the acceptance target from which the node 2Y accepts the connection from among the nodes 2 based on the midway activation date and time and the estimated activation date and time. As a result, the control device 300 can set a node 2X with an estimated start date and time as an acceptance target.

When the connection with the node 2X that is the child node is not completed, the reception processing unit 310D sets a node 2X that is different from the node 2X that could not be connected to the subsequent connection as a connection reception target. As a result, the control device 300 can improve the connection probability with the node 2X.

If the connection with the node 2X that is a child node is not completed, the acceptance processing unit 310D increases the connection acceptance time of the node 2Y that is a connection waiting time for the node 2X that has not been connected for the next and subsequent connections. Let As a result, the control device 300 can improve the connection probability with the node 2X.

The determination unit 310B calculates the estimated start date / time of the node 2X based on the period from the expected start date / time of the connection attempt of the node 2X to the expected end date / time of the connection attempt and the period required for accepting the connection of the node 2X. As a result, the control device 300 can calculate an appropriate estimated activation date / time according to the operation of the node 2X.

If the environment information 5 is a weather forecast, the communication unit 320 receives the environment information 5 from a wired or mobile phone network. As a result, the control device 300 can appropriately determine the connection acceptance time according to the environment of the node 2.

The determination unit 310B extracts the node 2 to be the node 2X from the plurality of nodes 2 based on the LQI between the node 2 and the node 2Y. As a result, the control device 300 can try to connect to a nearby node 2X within a predetermined distance from the control device 300.

The environmental information 5 includes environmental performance information about the environment so far and environmental prediction information about the future environment. As a result, the control device 300 can appropriately determine the connection acceptance time according to the environment of the node 2X.

The determination unit 310B calculates a correlation coefficient, which is a power characteristic of the node 2X, using the ideal power generation amount of the node 2X, the current power storage amount of the node 2X, and the previous power storage amount of the node 2X. As a result, the control device 300 can calculate an accurate correlation coefficient.

The determination unit 310B acquires the correlation coefficient from the node 2X during connection before the node 2X is not connected. As a result, the control device 300 can determine the connection acceptance time using the correlation coefficient of the node 2X even when the node 2X is not connected.

Note that the communication quality is not limited to, for example, LQI, and may be another index. Further, in the above embodiment, when all the connected nodes 2 searched are excluded from the nodes 2 in the vicinity of the acceptance target node 2, the acceptance processing unit 310D increases the acceptance time of the acceptance target node 2. . However, the acceptance processing unit 310D may increase the acceptance time of the acceptance target node 2 without setting the neighborhood exclusion node. In addition, when a part of the searched nodes 2 that have been searched are set as the neighbor exclusion nodes, the reception processing unit 310D may increase the reception time of the reception target node 2.

In the present embodiment, the control device 300 controls the node 2 using information on various dates and times such as connection acceptance date and time. However, the control device 300 may control the node 2 using information only on time. .

In addition, each component of each part illustrated does not necessarily need to be physically configured as illustrated. In other words, the specific form of distribution / integration of each part is not limited to the one shown in the figure, and all or a part thereof may be functionally or physically distributed / integrated in arbitrary units according to various loads and usage conditions. Can be configured.

Furthermore, various processing functions performed in each device are executed on the CPU (or a micro computer such as MPU (Micro Processing Unit), MCU (Micro Controller Unit), etc.) or all of them. Also good. Various processing functions may be executed entirely or arbitrarily on a program that is analyzed and executed by a CPU (or a microcomputer such as an MPU or MCU) or hardware based on wired logic. Needless to say.

DESCRIPTION OF SYMBOLS 1 Control system 2 Node 5 Environment information 300 Control apparatus 310 Control part 310A Connection process part 310B Determination part 310C Sleep instruction | indication part 310D Acceptance process part 320 Communication part 330 Storage part 330A Unconnected node information storage part 330B Connection node information storage part 330C Node State storage unit 330D Environmental information storage unit

Claims (14)

1. A communication unit that receives information from the first node using multi-hop communication between a plurality of nodes including a connected first node and an unconnected second node;
   The remaining battery level of the first node, the communication quality between the first node and the second node, the power characteristic of the second node, and the second node are arranged. A determination unit configured to determine an acceptance date and time when the first node accepts a connection with the second node based on first environment information regarding a location environment;
   A sleep instruction unit for instructing the first node to put the first node in a sleep state until the acceptance date and time;
   A control device comprising:
2. The sleep instruction unit
   2. The control device according to claim 1, wherein the control device instructs the third node to put a third node not arranged in a communication path from the control device to the second node into a sleep state. .
3. The determination unit is
   Based on the power characteristics of the second node and the second environment information related to the environment at the location where the second node is located, the remaining battery level of the second node is predicted, and the prediction result 2. The control device according to claim 1, wherein an estimated activation date and time of the second node is calculated based on the estimated activation date and time, and the reception date and time is determined using the estimated activation date and time.
4. The system further comprises an acceptance processing unit that sets a first acceptance target for the first node to accept a connection from the second nodes based on the acceptance date and the estimated activation date and time. 3. The control device according to 3.
5. The acceptance processing unit
   When the connection with the second node is not completed at the reception date and time, a second reception target different from the first reception target is set for the subsequent connection. Item 5. The control device according to Item 4.
6. The acceptance processing unit
   If the connection with the second node is not completed at the reception date and time, the connection acceptance period of the first node with respect to the second node for which connection has not been completed for the subsequent connection The control device according to claim 4, wherein the control device is increased.
7. The determination unit is
   Based on the prediction result and the first power consumption in a state where the second node is not operating, the estimated start date and time when the second node can start a connection attempt is estimated,
   Based on the prediction result and second power consumption in a state where the second node is trying to connect, an estimated end date and time when the second node ends the connection attempt,
   4. The estimated start date / time is calculated based on the expected start date / time, the expected end date / time, and a time required for the first node to accept a connection of the second node. The control device described.
8. The first environmental information is a weather forecast;
   The control device according to claim 1, wherein the communication unit receives the weather forecast from a wired or cellular phone network.
9. The determination unit is
   The control device according to claim 1, wherein the second node is extracted from the plurality of nodes based on communication quality between the plurality of nodes and the first node.
10. The second environmental information is
    The control apparatus according to claim 3, comprising environmental performance information related to the environment so far and environmental prediction information related to the future environment.
11. The determination unit is
    Based on the environmental performance information, the power generation amount of the first node is calculated,
    The power characteristic of the first node is calculated using the power generation amount of the first node, the current power storage amount of the first node, and the previous power storage amount of the first node. The control device according to claim 10.
12. 12. The determining unit acquires power characteristics of the second node from the second node during connection before the second node is not connected. The control apparatus as described in any one of these.
13. A plurality of nodes including a first node and a second node;
    A control device for controlling the plurality of nodes,
    The control device includes:
    A communication unit that receives information from the first node using multi-hop communication between the plurality of nodes;
    The remaining battery level of the first node, the communication quality between the first node and the second node, the power characteristic of the second node, and the second node are arranged. A determination unit configured to determine an acceptance date and time when the first node accepts a connection with the second node based on first environment information regarding a location environment;
    A sleep instruction unit for instructing the first node to put the first node in a sleep state until the acceptance date and time;
    A control system comprising:
14. Receiving information from the first node using multi-hop communication between a plurality of nodes including a connected first node and an unconnected second node;
    The remaining battery level of the first node, the communication quality between the first node and the second node, the power characteristic of the second node, and the second node are arranged. Based on the first environment information about the environment of the location, the first node determines an acceptance date and time for accepting a connection with the second node;
    Instructing the first node to put the first node in a sleep state until the acceptance date and time;
    A control method characterized by executing processing.

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