JP6931319B2 - Sensor network system design method and its program - Google Patents

Description

The present invention relates to a method for designing a sensor network system including a plurality of meters, and a program thereof.

Gas meters and electric power companies place gas meters and electricity meters at demand points in order to integrate the amount of gas and electric power used by consumers. In recent years, smart meters that have a communication function, perform bidirectional data communication with gas companies and electric power companies, and can automatically remotely read the amount of gas and electric power used have been in the limelight. There is. Such smart meters can also be used as an information source for improving the safety and utilization efficiency of infrastructure networks such as gas and electric power.

In addition, various means have been proposed to realize data communication between the above-mentioned smart meter and a gas company or an electric power company. For example, a short-range wireless device is installed in a smart meter to form a mesh-type network, a star-type network is formed by a mobile phone network such as 3G or LTE (Long Term Evolution), or a star-type network is formed by power line communication. It is conceivable to form a network.

In addition, as an application of the mesh type network, a technology is known in which a backbone network and ad hoc communication by wireless LAN are installed side by side, and the smart meter is operated stably by switching to ad hoc communication in the event of a failure of the backbone network (). For example, Patent Document 1). Further, a technique related to network routing is also open to the public (for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2012-0655422 Japanese Unexamined Patent Publication No. 2012-105258

As described above, by constructing a sensor network system that connects sensor nodes through ad hoc communication, it becomes possible to collect meter reading information (automatic meter reading) without the need for a meter reader to directly read the meter. It is possible to improve the efficiency of.

However, since the position of the sensor node is limited to the vicinity of the meter (near the consumer's house), the communication environment between the sensor nodes is also limited depending on the arrangement conditions of the meter, and an efficient sensor network system is constructed. It was difficult to do. In addition, since the timing of meter replacement is limited to the expiration date (expiration of the certification validity period), the sensor network system should be designed in consideration of the time when each sensor node can be effectively used. I had to.

In view of such a problem, an object of the present invention is to provide a method for designing a sensor network system capable of constructing an efficient sensor network system, and a program thereof.

In order to solve the above problems, a plurality of sensor nodes associated with the meter, a center device for collecting meter information through the sensor node, and a repeater for relaying between the sensor node and the center device are provided , and the sensor node is provided. The method of designing a multi-hop type sensor network system of the present invention in which a node is connected to a repeater by hopping another sensor node one or more times is associated with each of a plurality of meters whose verification validity period expires. A process of setting a reference reference node from an inspection node which is a sensor node, and a process of generating a group with a reference node and an inspection node whose distance from the reference node is less than or equal to a predetermined number satisfying a predetermined distance condition. , The process of excluding the inspection node included in the group from the candidates of the reference node is repeated, and when the group cannot be generated, the repeater is associated with the reference node.

If the distance from the reference node is less than the specified number of censored nodes that satisfy the distance condition, but the distance condition is not satisfied with other groups, the distance from the reference node and the reference node is less than the predetermined number that satisfies the distance condition. A group may be created with the check node.

If the number of inspection nodes whose distance from the reference node satisfies the distance condition is less than a predetermined number and the distance condition with another group is satisfied, the setting of the reference node may be canceled.

In order to solve the above problems, a plurality of sensor nodes associated with the meter, a center device for collecting meter information through the sensor node, and a repeater for relaying between the sensor node and the center device are provided , and the sensor node is provided. Targets a multi-hop sensor network system in which is connected to a repeater by hopping another sensor node one or more times , and the computer is associated with a sensor associated with each of the multiple meters whose verification validity period expires. The process of determining the reference reference node from the inspection node, which is a node, and the process of generating a group with the reference node and the inspection nodes whose distance from the reference node is less than or equal to a predetermined number satisfying a predetermined distance condition. A program is provided for repeating the process of excluding the inspection node included in the group from the candidates of the reference node and executing the process of associating the repeater with the reference node when the group cannot be generated.

According to the present invention, it is possible to construct an efficient sensor network system.

It is explanatory drawing which showed the schematic structure of the sensor network system. It is a functional block diagram which showed the schematic structure of a meter. It is a functional block diagram which showed the schematic structure of the center device. It is a flowchart for demonstrating the design method of a sensor network system. It is explanatory drawing for demonstrating the sensor network system to be constructed. It is explanatory drawing for demonstrating the relationship between the model number and the security number. It is a flowchart which showed the processing flow of a center apparatus. It is explanatory drawing for demonstrating the target period of billing information.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, other specific numerical values, etc. shown in the embodiment are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are designated by the same reference numerals to omit duplicate description, and elements not directly related to the present invention are not shown. do.

(Sensor network system 100)
FIG. 1 is an explanatory diagram showing a schematic configuration of the sensor network system 100. As shown in FIG. 1, the sensor network system 100 includes a plurality of meters 110, a plurality of sensor nodes 112, a plurality of repeaters 114, and a center device 116.

The meter (smart meter) 110 is installed for each consumer, for example, and at least uses gas or electric power when the gas operator supplies gas to the consumer or the electric power operator supplies electric power to the consumer. It is a device that automatically reads the amount. In this embodiment, for convenience of explanation, the gas meter 110 by the gas company is illustrated, but it goes without saying that it can also be applied to electric power (electricity).

FIG. 2 is a functional block diagram showing a schematic configuration of the meter 110. The meter 110 includes a shutoff valve 150, a pressure sensor 152, a flow rate sensor 154, a display unit 156, and a calculation unit 158. In FIG. 2, the flow of the control signal is indicated by a solid arrow, and the flow of the flammable gas is indicated by a broken line arrow.

The shutoff valve 150 includes a valve, controls the opening degree of the valve, and controls the flow rate of the flammable gas flowing through the gas flow path 148. Therefore, the shutoff valve 150 can shut off the flow of flammable gas by completely closing the valve. The pressure sensor 152 is provided downstream of the shutoff valve 150 and detects the pressure of the flammable gas.

The flow rate sensor 154 is composed of ultrasonic vibrators 154a and 154b and a propagation velocity derivation unit 154c. The ultrasonic vibrators 154a and 154b are arranged at predetermined positions on the upstream side surface and the downstream side side surface of the gas flow path 148 downstream of the shutoff valve 150 and upstream of the pressure sensor 152, for example, with sound waves of 20 kHz or higher. It functions as a transmitter and receiver of certain ultrasonic waves. The propagation velocity derivation unit 154c detects the propagation time of the ultrasonic waves propagating between the ultrasonic vibrators 154a and 154b via the flammable gas, and derives the flow rate of the flammable gas based on the propagation time.

The display unit 156 is composed of a liquid crystal display, an organic EL (Electro Luminescence) display, and the like, and is used to notify an integrated value of the supply amount (usage amount) of the flammable gas and an abnormality such as a leak of the flammable gas. ..

The arithmetic unit 158 manages and controls the entire meter 110 by a semiconductor integrated circuit including a central processing unit (CPU), a PROM in which a program or the like is stored, a RAM as a work area, and the like. Further, the calculation unit 158 functions as a threshold value update unit 160 and a cutoff control unit 162 in cooperation with the program. The threshold value update unit 160 and the cutoff control unit 162 will be described in detail later.

Returning to FIG. 1, the sensor nodes 112 are installed in a one-to-one correspondence with each of the meters 110, and at least transmit and receive information (data) used by the meters 110.

The repeater (gateway device) 114 is installed in association with any of the plurality of sensor nodes 112, establishes wired communication with the associated sensor node 112, and wirelessly communicates with the center device 116 through the base station 118. Establish communication. Then, the repeater 114 establishes wireless communication with one or a plurality of surrounding sensor nodes 112 through the associated sensor node 112.

However, since the communication of the sensor node 112 is realized by short-range radio, not all sensor nodes 112 can directly establish wireless communication with the sensor node 112 associated with the repeater 114. In this case, the sensor node 112 is connected to the repeater 114 by hopping another sensor node 112 capable of wireless communication one or more times. In this way, the repeater 114 transfers the information of each sensor node 112 to the center device 116 through the associated sensor node 112 and other sensor nodes 112 around it, and transfers the information of the center device 116 to the surrounding sensor nodes 112. Can be sent to. At this time, since the transmitted information also includes an identifier that identifies the repeater 114 that was passed through when the information was transmitted, the center device 116 can specify the source of the information.

The center device 116 is a device composed of a computer or the like and belongs to the administrator side of the sensor network system 100 such as a gas company or an electric power company, and collects information on one or a plurality of repeaters 114, or one or one. Information is transmitted to a plurality of repeaters 114. The position (coordinate information) where the meter 110 is installed is managed in the center device 116 through conduit mapping (GIS system). Therefore, the positions of the sensor node 112 and the repeater 114 can also be specified by the conduit mapping.

FIG. 3 is a functional block diagram showing a schematic configuration of the center device 116. The center device 116 includes a center communication unit 170, a center holding unit 172, and a center control unit 174.

The center communication unit 170 establishes wireless communication with the repeater 114 through the base station 118. The center holding unit 172 is composed of a ROM, a RAM, a flash memory, an HDD, and the like, and holds a program and various information used in the center device 116. The center control unit 174 is composed of a CPU and a DSP (Digital Signal Processor), and controls the entire center device 116 by using a program stored in the center holding unit 172. Further, the center control unit 174 functions as a data acquisition unit 180, an information generation unit 182, and an information transmission unit 184 in cooperation with the program. The data acquisition unit 180, the information generation unit 182, and the information transmission unit 184 will be described in detail later.

Here, communication between each device will be described. For example, a communication charge between the repeater 114 and the center device 116 according to the amount of communication such as a mobile phone network including a base station 118, a PHS (Personal Handyphone System) network, for example, LTE (Long Term Evolution). Wireless communication is established through the existing pay communication network. Further, wireless communication between the sensor nodes 112 is established, for example, through a smart meter wireless system (U-Bus Air) that uses the 920 MHz band. It is assumed that the wireless communication between the sensor nodes 112 is free of charge, but the communication cost may be at least lower than the wireless communication between the repeater 114 and the center device 116 regardless of whether the sensor nodes are charged or free of charge. Through such wireless communication, the repeater 114 is connected to the center device 116 through the pay communication network and is connected to each sensor node 112 through the smart meter wireless system.

In this embodiment, the meter 110 and the sensor node 112 are arranged in units of a plurality of consumers. In some cases, a repeater 114 may be installed. The center device 116 collects information on the meter 110 or controls the meter 110 through the sensor node 112 and the repeater 114. Therefore, the sensor node 112 and the repeater 114 will be arranged at any position where the consumer exists.

Here, at the installation location of the repeater 114, the smart meter wireless system by the sensor node 112 and the pay communication network by the repeater 114 are used in combination, and the existing base station dedicated to the smart meter wireless system is not separately provided. By using the pay communication network, communication between the center device 116 and the sensor node 112 can be established easily and inexpensively.

Further, in the combination of the repeater 114 and the plurality of sensor nodes 112 around it, only the repeater 114 uses the pay communication network, and all the other sensor nodes 112 use the wireless system for smart meters that does not incur communication charges. doing. Therefore, it is possible to significantly reduce the communication cost.

For example, the repeater 114 collects information from a plurality of surrounding sensor nodes 112 through a wireless system for smart meters through a sensor node 112 associated with the repeater 114, and collects the collected information on a daily basis through a pay communication network. It is transmitted to the center device 116. In this way, the use of the pay communication network of the repeater 114 can be minimized, and the communication cost can be reduced.

Since the wireless system for smart meters assumes short-range wireless communication, the power consumed for wireless communication is relatively small. Therefore, the power source of the sensor node 112 can be supplied by a battery or the like, and the power consumption of the sensor network system 100 can be reduced. Since the pay communication network consumes power relatively easily compared to the wireless system for smart meters, it requires a large capacity battery or a separate power source, but since the absolute number of repeaters 114 is smaller than that of the sensor node 112. Compared with the case of using the mobile phone network from all the meters 110, the power consumption can be suppressed to an extremely low level. Hereinafter, the arrangement of the sensor node 112 and the repeater 114 will be described in detail.

(Design method of sensor network system 100)
As described above, by constructing the sensor network system 100 that connects the sensor nodes 112 to each other, it is possible to collect meter reading information (automatic meter reading) even if the meter reader of the gas company does not directly read the meter 110. This makes it possible to improve work efficiency.

However, since the sensor node 112 is associated with the meter 110, its position is limited to the vicinity of the meter 110 (near the consumer's house), and the communication environment between the sensor nodes 112 is also limited depending on the arrangement conditions of the meter 110. It ends up. Then, it was difficult to construct an efficient sensor network system 100. Further, since the timing at which the meter 110 is replaced is also limited to the expiration date (when the verification validity period expires), the sensor network system 100 also takes into consideration the time when each sensor node 112 can be effectively used. Had to design.

Therefore, in the present embodiment, a method for designing a sensor network system 100 capable of constructing an efficient sensor network system 100 without installing an unnecessarily large number of repeaters 114 is provided.

FIG. 4 is a flowchart for explaining a design method of the sensor network system 100, and FIG. 5 is an explanatory diagram for explaining the sensor network system 100 to be constructed. The meter 110 has a fixed test validity period, for example, 10 years, and must be replaced when the test validity period expires. However, instead of replacing all the meters 110 at once, for example, by replacing 1/10 of the total amount every year, the goal is to complete the replacement of the total amount after at least 10 years.

Therefore, the flowchart of FIG. 4 is performed once a year for the meter 110 whose verification validity period expires. Further, in FIG. 5, the meter 110 (or the sensor node 112 associated with the test node 112) whose test validity period has expired is shown in white, and the meter 110 whose test validity period has not yet expired is shown in black. Further, the meter 110 whose verification validity period has expired may be referred to as an "inspection meter", and the sensor node 112 arranged in association with the inspection meter may be referred to as an "inspection node". The design method of the sensor network system 100 described below is realized by using a predetermined device (computer).

First, the predetermined device determines whether or not there is an inspection node (inspection meter) that has not yet been selected in this process in the target area (S200). Then, if there is an inspection node in the target area (YES in S200), the meter 110 of one of the inspection nodes is arbitrarily selected and set as a reference node (S202). Here, in FIG. 5A, the inspection node indicated by “A” is used as the reference node.

Subsequently, it is determined whether or not there are a predetermined number of inspection nodes whose distance from the reference node satisfies a predetermined distance condition (S204). Here, the predetermined distance condition is that the inspection nodes are within a distance considered to be adjacent to each other. Specifically, is the inspection node located within a predetermined distance (for example, 30 m) from the reference node? Or, whether or not another inspection node is located within a predetermined distance from the inspection node determined to be located at a predetermined distance. As such a predetermined distance, an appropriate value (here, 30 m) capable of stably realizing communication is adopted by an experiment or the like. Therefore, if the distances between the plurality of inspection nodes chained to the reference node are all within a predetermined distance, all the inspection nodes satisfy the distance condition. For example, in the example of FIG. 5A, the three inspection nodes shown by “B” are targeted with respect to the reference node of “A”. Here, the inspection nodes that satisfy a predetermined distance condition are connected by a broken line.

Further, the predetermined number is smaller than the maximum allowable number of the sensor nodes 112 to which the repeater 114 can be connected. By making the predetermined number less than the maximum allowable number in this way, if the inspection node added in the next fiscal year or later is adjacent to the reference node, communication with the inspection node added by the reference node can be performed. It can be tolerated. The predetermined number is an appropriate value assuming that each repeater 114 can allow communication with the sensor node 112 which is equal to or less than the maximum allowable number after a predetermined year (for example, 10 years). For example, the maximum allowable number is "50". The predetermined number is set to "30". However, in FIG. 5, for convenience of explanation, the predetermined number is described as “3”.

In this way, when a predetermined number is reached while extracting the inspection nodes satisfying the predetermined distance condition (YES in S204), regardless of whether or not there is an inspection node satisfying the predetermined distance condition. Instead, a group is generated by the reference node and the extracted inspection nodes whose distance from the reference node is equal to or less than a predetermined number satisfying a predetermined distance condition (S206). For example, in the example of FIG. 5A, a group “C” including three “B” inspection nodes with “A” as a reference node is generated.

Subsequently, the inspection node included in the group thus generated is excluded from the candidates of the reference node (S208), and the processing from the inspection node determination process S200 is repeated. Therefore, the inspection node excluded from the candidates of the reference node is not the target of the inspection node determination process S200. This is because it is determined that the inspection node included in the group can establish communication with the center device 116 through the repeater 114 installed in the reference node, so that it is not necessary to make it a candidate for the reference node again. .. In this way, the load on the inspection node determination process S200 can be reduced.

For example, in FIG. 5A, the grouped “B” inspection nodes are excluded from the candidates for the reference node. Therefore, in the next inspection node determination process S200, as shown in FIG. 5B, The inspection node excluding the inspection node of "B", for example, the inspection node indicated by "D" is set as the reference node. Then, in step S204, with respect to the reference node of “D” in FIG. 5 (b), the three inspection nodes indicated by “E” are targeted, and the three “E” with “D” as the reference node. A group "F" containing the inspection nodes of is generated. In this way, new groups are sequentially generated.

Further, when the number of the inspection nodes satisfying the predetermined distance condition is less than the predetermined number (NO in S204), the sensor node group of the reference node and the extracted inspection nodes less than the predetermined number has already been generated. It is determined whether or not a predetermined distance condition is satisfied with another group (S210). Here, if the sensor node group does not satisfy a predetermined distance condition with another group (NO in S210), the sensor node group, that is, the reference node and the extracted less than a predetermined number of inspection nodes form a group. Generate (S212). For example, the sensor node group including the two “H” inspection nodes with “G” as the reference node in FIG. 5C does not satisfy the predetermined distance condition with the other groups “C” and “F”. Therefore, a group "I" is generated including two "H" inspection nodes with "G" as a reference node. Since such a sensor node group does not satisfy a predetermined distance condition with other groups, it is unlikely that communication will be established not only in this year but also in the next year and thereafter. Here, even if the number of such sensor node groups is less than a predetermined number, it is possible to establish communication with many sensor nodes 112 by treating them as independent groups.

Then, as in the case where the group is generated in the group generation process S206, the inspection nodes included in the generated group are excluded from the candidates of the reference node (S208), and the processing from the inspection node determination process S200 is repeated. ..

Further, when the sensor node group satisfies a predetermined distance condition with another group (YES in S210), the setting of the reference node is canceled and the sensor node group becomes a simple inspection node (S214). For example, since the sensor node group including the inspection node of "K" with "J" as the reference node in FIG. 5D satisfies the predetermined distance condition with the other groups "C" and "F", " Cancel the setting of the reference node of "J". Here, the reason why the sensor node group is not grouped is that it satisfies the predetermined distance condition with other groups, so it is assumed that communication is established with the inspection nodes of other groups, and communication is performed this year. This is because there is a high possibility that communication will be established in the next fiscal year or later even if it is not established. By not setting an unnecessarily large number of reference nodes in this way, it is possible to construct an efficient sensor network system 100 while suppressing the absolute number of repeaters 114.

Further, if the setting of the reference node is simply canceled, the same inspection node can be set again as the reference node in the inspection node determination process S200. Therefore, here, in order to prevent unnecessary processing from being repeated, extraction is performed. All the checked nodes are excluded from the candidates of the reference node (S208), and the process from the checked node determination process S200 is repeated.

In this way, the ungrouped inspection nodes may become candidates for reference nodes and grouping may be promoted, for example, when new inspection nodes are generated in the next fiscal year or later. Further, when a new building is constructed and the number of sensor nodes 112 satisfying a predetermined distance condition is increased, the number of inspection nodes may increase to a predetermined number or more, and grouping may be possible.

Then, in the inspection node determination processing S200, if there is no inspection node that has not been selected in this processing, or if there is an inspection node but it is excluded from the candidates of the reference node (in S200). NO), the repeater 114 is associated with all the set reference nodes (S216), and the design method of the sensor network system 100 is completed.

In this way, the existing meter 110 whose certification validity period has expired is replaced with a new meter 110. A sensor node 112 is associated with the new meter 110. Further, in addition to the meter 110 and the sensor node 112, a repeater 114 is attached to the sensor node 112 (or the meter 110 associated with the sensor node 112) set as the reference node. In this way, the sensor network system 100 in which the repeater 114 is appropriately arranged is updated at the timing when the verification validity period expires.

In the above design method of the sensor network system 100, after at least a predetermined year (for example, 10 years), all the meters 110 are replaced with the meters 110 associated with the sensor node 112, and all the meters 110 communicate with each other by the sensor node 112. It is designed for when it becomes possible. However, as described above, since only the meter 110 corresponding to the inspection node is actually replaced, the sensor node 112 is added only at a predetermined ratio (for example, 1/10) every year. Therefore, by this method, the sensor network system 100 is not completely constructed in the first year, and even the replaced meter 110 may not be able to communicate with the center device 116. In that case, the repeater 114 is not installed unnecessarily, and the meter reader individually reads the meter.

The maximum permissible number of repeaters 114 is larger than a predetermined number. Therefore, even if the inspection node is not included in the group, the inspection node may be able to establish communication with other inspection nodes and reference nodes belonging to the group and communicate with the center device 116. .. In this case, if there is a combination of the repeater 114 and the sensor node 112 that have established stable communication by referring to the connection record at that time and in the past, it is considered that the communication has already been established and the communication is established. After fixing the route (excluded from the target of the inspection node determination process S200), the above design method may be executed for the other sensor node 112.

As for the meter 110 corresponding to the inspection node that has not been constructed as the sensor network system 100 even when the predetermined year is approached or the predetermined year has passed, the predetermined number of meters 110 satisfying the predetermined distance condition. Even if it is less than the above, one of the inspection nodes may be used as the reference node. In this way, communication with all meters 110 becomes possible.

With such a configuration, the meter whose verification validity period has expired can be appropriately replaced with the meter 110 every year, and the repeater 114 can be uniformly and efficiently arranged according to a predetermined rule. Therefore, looking ahead to a predetermined year, we will construct an efficient sensor network system 100 in which the absolute number of repeaters 114 is suppressed and the number of repeaters 114 is appropriately distributed (balanced). It becomes possible.

(Change in security number)
By using the sensor network system 100 constructed in this way, it is possible to collect meter reading information (automatic meter reading) without the meter reader directly reading the meter 110, and it is possible to improve work efficiency. can. However, when the usage situation of the consumer changes and the meter 110 corresponding to the changed usage situation becomes necessary, the worker also goes to the consumer's house and directly replaces the meter 110 of the corresponding security number. Business efficiency was not sufficient. Therefore, in the present embodiment, the meter 110 is standardized and an efficient sensor network system 100 is constructed.

By the way, the outer shape and the size of the internal structure of the meter 110 differ depending on the number of security numbers indicating the maximum flow rate in use per unit time. However, only the "size (scale)" changes in terms of hardware due to the difference in the number of security issues. Therefore, a meter 110 having a large number of security numbers cannot be replaced by a meter 110 having a small number of security numbers, but vice versa, that is, a meter 110 having a small number of security numbers cannot be replaced by a meter 110 having a large number of security numbers. can. Then, the meter 110 can be standardized by using the meter 110 having a large number of security issues. Here, as the meter 110, two models, a UH type and a JO (MO) type, which have almost the same functions but different appearances, will be illustrated.

FIG. 6 is an explanatory diagram for explaining the relationship between the model number and the security number. Here, five models (model number) are prepared for each model as a common meter 110. In the UH type shown in FIG. 6A, each of the meters 110 having the model numbers of 1.6, 2.5, 3, 4, and 6 also serves as one or more security numbers. For example, the meter 110 with the model number 1.6 corresponds only to the security number 1.6, but the meter 110 with the model number 6 has the security number 1.6. It can handle 7 types of No., No. 2.5, No. 3, No. 4, No. 4.5, No. 5, and No. 6. Further, in the JO type shown in FIG. 6B, each of the meters 110 having the model numbers 1, 1.6, 2.5, 4 and 6 also serves as one or more security numbers. do. For example, the meter 110 with the model number 1 corresponds only to the security number 1, but the meter 110 with the model number 6 has the security numbers 1 and 1.6. , 2.5, 3, 4, 4.5, 5, 5 and 6 can be handled.

Therefore, the worker of the gas company can easily respond to the change of the security number by installing the meter 110 having a model number larger than the original security number used by the consumer. For example, even if the number of security issues that the consumer wants to use is 3, by intentionally installing the meter 110 with the model number 6, even if the usage status of the consumer changes, the main unit will be replaced. Without doing so, it is possible to change to a small number of security issues such as 1.6 and 2.5, and to a large number of security issues such as 4, 4.5, 5 and 6.

However, even if the main body of the meter 110 can be shared, the software inside the meter 110 cannot be shared. Specifically, the process of determining interruption or warning in the meter 110 differs depending on each security number. Such determination processing includes, for example, "total maximum flow rate over-blocking", "individual maximum flow rate over-blocking", and "flow rate over-alarm", each of which has a plurality of threshold values for performing the determination processing.

Here, the "total maximum flow rate over shutoff" is a determination process for closing the shutoff valve 150 within 1 minute when the flow rate of the flammable gas reaches an abnormal value exceeding the threshold value due to breakage of the gas flow path 148 or the like. Is. In addition, "individual maximum flow rate over-blocking" is within 1 minute when the flow rate of flammable gas exceeds the threshold value and increases abnormally due to the gas plug being accidentally opened or the rubber tube being accidentally removed. This is a determination process for closing the shutoff valve 150. Further, the "flow rate over alarm" is a determination process for giving a warning through a display unit 156 or an alarm speaker (not shown) when the average flow rate of the flammable gas for 30 seconds becomes an abnormal value exceeding the threshold value.

The threshold value of these judgment processes differs depending on the number of security issues. In addition, the threshold value may change with the passage of time. Here, in addition to standardizing the meters 110, the security number for each meter 110 is set remotely through the sensor network system 100, so that it is efficient while suppressing the on-site dispatch of workers and complicated work. A sensor network system 100 is constructed.

Specifically, the information transmission unit 184 of the center device 116 transmits only the number information indicating at least the security number to the sensor node 112 associated with the target meter 110. Then, the threshold value updating unit 160 of the meter 110 extracts the security number from the number information and updates the security number held by itself. The cutoff control unit 162 determines the number of security issues (or the number of security issues and the elapsed years) and the threshold values for a plurality of judgment processes (total maximum flow rate over-blocking, individual maximum flow rate over-blocking, flow rate over alarm) held by itself. From the table uniquely associated with each other, the threshold values of a plurality of judgment processes corresponding to the updated security number are read at once, and the shutoff valve 150 is shut off or the display unit 156 is shut off according to the plurality of threshold values. Or alert through the alarm speaker. Further, the cutoff control unit 162 may refer to its own timer, change the reference position of the table depending on whether or not one year has passed since the installation, and read the threshold value.

Using such a table, for example, when the security number of the JO type meter 110 that has been installed for less than one year is changed from "3" to "4", the information transmission unit 184 of the center device 116 may be used. The number information indicating the security number "4" is transmitted to the sensor node 112 associated with the target meter 110. Then, the threshold value updating unit 160 of the meter 110 extracts and holds the security number "4" from the number information. The cutoff control unit 162 reads out the threshold value corresponding to the security number "4" instead of the security number "3" up to that point from the table held by itself. Then, the threshold values of "total maximum flow rate over-blocking", "individual maximum flow rate over-blocking", and "flow rate over-alarm" are updated to different values. When the flow rate of the flammable gas exceeds such a threshold value, the shutoff control unit 162 shuts off the shutoff valve 150 or warns through the display unit 156 or the alarm speaker.

As described above, it is possible to change (set) the threshold values of a plurality of determination processes at once only by a simple process such as setting the security number through the sensor network system 100. In this way, it is possible to construct a sensor network system 100 capable of appropriately responding to changes in the usage situation of consumers while suppressing the on-site dispatch of workers and complicated work.

(Billing information generation)
Further, when the sensor network system 100 is constructed, the center device 116 collects the meter reading information of the meter 110 through the sensor node 112, and generates the billing information for billing the consumer based on the meter reading information. However, if the meter reading information cannot be collected for some reason, such as the communication between the sensor nodes 112 cannot be established on the meter reading date, which is the standard for billing, the meter reader will still use the meter for billing. You will have to read the meter directly. Here, the purpose is to generate billing information even if meter reading information cannot be obtained.

As described above, the data acquisition unit 180 of the center device 116 acquires meter reading information including the meter reading result and the like from the sensor node 112 at least at a predetermined timing (for example, once a month on the meter reading day). Then, the information generation unit 182 generates billing information based on the acquired meter reading information. Here, the meter reading result is, for example, the flow rate (total flow rate) of the flammable gas integrated from the installation. Therefore, the information generation unit 182 derives the total flow rate of the flammable gas used from the previous time to the present time by subtracting the meter reading result (total flow rate) in the previous meter reading information from the meter reading result (total flow rate) in the current meter reading information. However, billing information is generated according to the total flow rate used. Then, the generated billing information will be presented to the consumer.

At this time, if the meter reading information cannot be normally acquired from the sensor node 112 at a predetermined timing, the information generation unit 182 refers to the past meter reading information to generate billing information. Specifically, the data acquisition unit 180 acquires meter reading information from the sensor node 112 at a predetermined cycle (for example, once a day) regardless of a predetermined timing, and holds the meter reading information in the center holding unit 172. Then, when the meter reading information cannot be normally acquired from the sensor node 112 at a predetermined timing, the information generation unit 182 acquires the meter reading information normally acquired in the past from the center holding unit 172, for example, the meter reading information one day before. Refer to it and generate billing information based on the meter reading information. At this time, if the meter reading information one day ago is not normally acquired, the reference is repeated until the normally acquired meter reading information is extracted, such as referring to the meter reading information two days ago.

FIG. 7 is a flowchart showing a processing flow of the center device 116, and FIG. 8 is an explanatory diagram for explaining a target period of billing information. Here, the predetermined timing for meter reading will be described as once a month, for example, the 5th day of each month.

First, the data acquisition unit 180 of the center device 116 determines whether or not the predetermined cycle (for example, 12 o'clock every day) has been reached (S300), and until the predetermined cycle is reached (NO in S300), the predetermined cycle determination process S300 is performed. repeat. Then, when the predetermined cycle is reached (YES in S300), the data acquisition unit 180 acquires the meter reading information from the sensor node 112 and causes the center holding unit 172 to hold the meter reading information in association with the acquired date and time (S302). At this time, if the meter reading information cannot be acquired normally, that fact is retained.

Subsequently, the data acquisition unit 180 determines whether or not a predetermined timing (for example, the 5th day of each month) has been reached (S304), and repeats from the predetermined cycle determination process S300 until the predetermined timing is reached (NO in S304). .. Then, when the predetermined timing is reached (YES in S304), the information generation unit 182 determines whether or not the meter reading information acquired by the data acquisition unit 180 is a normal value (S306). Here, the normal value indicates a value in which communication between the sensor nodes 112 is normally established and normally acquired. Therefore, if the meter reading information cannot be normally collected for some reason, such as the communication between the sensor nodes 112 cannot be established, it is determined that the value is not a normal value.

If the meter reading information is a normal value (YES in S306), the information generation unit 182 generates billing information based on the acquired meter reading information (S308). Specifically, as shown in FIG. 8A, the target period is from September 5th to October 5th, and the information generation unit 182 indicates the meter reading result (total flow rate) in the meter reading information of this time (for example, October 5). ) To the previous meter reading information (for example, September 5), the meter reading result (total flow rate) is subtracted to derive the total flow rate used, and billing information is generated according to the total flow rate used.

On the other hand, if the meter reading information is not a normal value (NO in S306), the information generation unit 182 refers to the meter reading information one time past from the center holding unit 172, for example, the meter reading information one day before (S310). Then, the information generation unit 182 determines whether or not the referenced meter reading information is a normal value (S312). If the meter reading information is not a normal value (NO in S312), the meter reading information reference process S310 is repeated until the normal meter reading information is referenced.

If the meter reading information is a normal value (YES in S312), billing information is generated based on the meter reading information (S308). For example, as shown in FIG. 8B, when the meter reading information cannot be normally acquired on the meter reading date (October 5) and the meter reading information one day before (October 4) can be normally acquired, the target is The period is from September 5th to October 4th, and the information generation unit 182 uses the meter reading information one day before (October 4th) that was normally acquired, and uses the meter reading information of this time (for example, October 4th). The meter reading result (total flow rate) in the previous meter reading information (for example, September 5) is subtracted from the meter reading result (total flow rate) to derive the total flow rate used, and billing information is generated according to the total flow rate used.

In this way, by making the meter reading information that is the basis of the billing information a thing of the past, billing will not be performed until the meter reading date, but that amount will not be missed by carrying it over to the next time. ..

That is, when the past meter reading information is used in the generation of the previous billing information, the information generation unit 182 generates the current billing information using the past meter reading information as a starting point. For example, as shown in FIG. 8C, when the meter reading information could not be normally acquired on the meter reading date (October 5) and the meter reading information one day before (October 4) was normally acquired was used. Next time, the information generation unit 182 will generate billing information with October 4th as the starting point (starting date) using the meter reading information.

In this way, billing information can be generated based on the meter reading information several days before the meter reading date, although it is not the day of the meter reading. Therefore, even if the meter reader does not directly read the meter 110, it is possible to reliably generate the billing information on the day of the meter reading.

If the meter reading information cannot be acquired normally for multiple days (for example, 10 days) or more, the target sensor node 112 may have some kind of communication failure and cannot be charged properly. Therefore, the meter reading information can only be performed in that case. The staff may go to the site for meter reading.

Although the preferred embodiment of the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such an embodiment. It is clear that a person skilled in the art can come up with various modifications or modifications within the scope of the claims, which naturally belong to the technical scope of the present invention. Understood.

In addition, a program that causes the computer to function as the device for designing the sensor network system 100, the meter 110, the sensor node 112, or the center device 116, and a computer-readable flexible disc or magneto-optical disc that records the program. , ROM, CD, DVD, BD and other storage media are also provided. Here, the program refers to a data processing means described in an arbitrary language or description method.

It should be noted that each process shown in the present specification does not necessarily have to be processed in chronological order in the order described in the flowchart, and may include parallel or subroutine processing.

The present invention can be used in a method for designing a sensor network system including a plurality of meters and a program thereof.

100 Sensor network system 110 Meter 112 Sensor node 114 Repeater 116 Center device 150 Shutoff valve 154 Flow sensor 156 Display unit 158 Calculation unit 160 Threshold update unit 162 Blocking control unit 172 Center holding unit 174 Center control unit 180 Data acquisition unit 182 Information generation Department 184 Information transmission unit

Claims (4)

A plurality of sensor nodes associated with the meter, a center device that collects information on the meter through the sensor node, and a repeater that relays the sensor node and the center device are provided , and the sensor node is another sensor. A method of designing a multi-hop type sensor network system in which a node is hopped one or more times and connected to a repeater.
The process of setting the reference reference node from the inspection node, which is the sensor node associated with each of the multiple meters whose verification validity period expires,
A process of generating a group with the reference node and a predetermined number or less of the inspection nodes whose distance from the reference node satisfies a predetermined distance condition.
The process of excluding the inspection node included in the group from the candidates of the reference node, and
Repeat,
A method for designing a sensor network system in which the repeater is associated with the reference node when the group cannot be generated. When the number of inspection nodes whose distance from the reference node satisfies the distance condition is less than the predetermined number, but the distance condition is not satisfied with other groups, the distance between the reference node and the reference node is the distance. The method for designing a sensor network system according to claim 1, wherein a group is generated with the number of inspection nodes less than the predetermined number satisfying the conditions. Claim 1 or 2 for canceling the setting of the reference node when the number of inspection nodes whose distance from the reference node satisfies the distance condition is less than the predetermined number and the distance condition from the reference node is satisfied with another group. The method of designing the sensor network system described. A plurality of sensor nodes associated with the meter, a center device that collects information on the meter through the sensor node, and a repeater that relays the sensor node and the center device are provided , and the sensor node is another sensor. For multi-hop sensor network systems where nodes are hopped one or more times and connected to repeaters
On the computer
The process of determining the reference reference node from the inspection node, which is the sensor node associated with each of the multiple meters whose verification validity period expires,
A process of generating a group with the reference node and a predetermined number or less of the inspection nodes whose distance from the reference node satisfies a predetermined distance condition.
The process of excluding the inspection node included in the group from the candidates of the reference node, and
To repeat
A program for causing the reference node to execute a process of associating the repeater when the group cannot be generated.

Images