JP4990705B2 - Safety confirmation method - Google Patents

Description

  The present invention relates to a safety confirmation method using a sensor with a wireless communication function.

Conventionally, when working in a tunnel or tunnel, it is necessary to detect toxic gas, oxygen deficiency, etc. in order to ensure safety. There is a method to confirm, but this method has a problem in the safety of the worker himself. Thus, techniques for solving such problems are disclosed in Patent Document 1 and Patent Document 2. The technology of Patent Document 1 is an optical gas detection method in a long-distance monitoring area such as a tunnel, and is a method of detecting gas using an optical fiber laid in advance. The technology of Patent Document 2 is a gas detection system, which is a system that acquires gas detection information at a remote location via a wireless communication network or another network.
JP-A-8-68747 JP 2003-296853 A

  However, the techniques disclosed in Patent Document 1 and Patent Document 2 require infrastructure facilities for detecting gas in advance and have problems in cost and safety. In particular, the technique of Patent Document 1 requires a dedicated facility for gas detection, and has a problem that it cannot be introduced into a construction site. Moreover, the technique of patent document 2 assumes the shape which attaches a gas sensor along with a human body, and when gas is detected, there exists a possibility of being late.

  The present invention has been made in view of the above problems, and a main object thereof is to confirm safety in a space such as a tunnel or a tunnel at low cost and safely.

In order to solve the above problems, the present invention provides a sensor node having a data communication relay function and an abnormal state detection function, and a terminal that is capable of wireless communication with the sensor node and moves in a predetermined space. A method for confirming safety in a predetermined space, (1) For the sensor node installed at a location where the terminal is separated from the terminal in the moving direction of the terminal in the predetermined space, If a detection result and a received signal strength display signal are received from the sensor node and no abnormal state is detected from the detection result, a distance from the sensor node is calculated based on the received signal strength display signal (2 ) When the calculated distance is less than or equal to the predetermined value, the terminal displays a message to that effect on the display unit. (3) After the terminal displays the message (4) The processing of (1) to (3) is repeated for a new sensor node installed at a location separated in the moving direction of the terminal .
According to this method, it is possible to confirm the safety from the entrance to the back of a tunnel or a cave while ensuring its own safety. In addition, since the sensor node is installed at a predetermined distance, safety can be confirmed at a low cost.

Further, the present invention is a safety confirmation method, wherein ad hoc communication is established between sensor nodes and between sensor nodes and terminals, and the sensor node stores a node ID unique to the sensor node in a storage unit, When an abnormal state in a predetermined space is detected, data relating to the abnormal state is generated, the node ID is added to the data, and the data is transmitted to the terminal by the ad hoc communication. Using the distance from the sensor node calculated based on the display signal, the position of the sensor node in a predetermined space is specified, and installation position information including the specified position and the node ID of the sensor node is stored in the storage unit. Storing and extracting the node ID added to the data when the data regarding the abnormal state is received from the sensor node; Referring to serial installation location information, identifies the location of the sensor node corresponding to the node ID, and characterized in that the display unit as a detection position of the abnormal state.
According to this configuration, since the position of the sensor node that has detected the abnormal state is displayed on the display unit of the terminal, it is possible to make the worker in the predetermined space recognize the occurrence and the position of the abnormal state. , Can be encouraged to ensure their own safety.

The present invention is also a safety confirmation method, wherein the terminal stores space information including a position of an entrance / exit of a predetermined space in a storage unit, and the entrance / exit from the position of the sensor node displayed on the display unit An arrow heading to the position of is displayed as an evacuation direction, and while receiving a received signal strength display signal from the sensor node, a temporal change in the received received signal strength display signal is detected, and the direction of movement according to the change The movement direction is compared with the evacuation direction, and if they do not match, the correct movement direction is displayed.
According to this configuration, in the event of an emergency such as a fire in a tunnel, a combination of a smoke sensor and a temperature sensor can be used to guide an appropriate evacuation route and to correctly indicate the actual moving direction. it can.

  The present invention includes a method of confirming safety using a terminal after installing one relay node and a plurality of sensor nodes. In addition, the problems disclosed in the present application and the solutions thereof will be clarified by the column of the best mode for carrying out the invention and the drawings.

  ADVANTAGE OF THE INVENTION According to this invention, the safety in spaces, such as a tunnel and a tunnel, can be confirmed at low cost and safely.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. In the safety confirmation method according to the embodiment of the present invention, as a means for easily detecting gas, an operator arranges a plurality of sensor nodes, which are gas sensors with a wireless communication function, inside a tunnel, a tunnel, a pipe, or the like. In addition, by remotely grasping the presence of gas at an arbitrary location by ad hoc communication, safety can be confirmed without approaching the location where the gas exists. In addition, in the event of an emergency such as a fire in a tunnel, it is possible to cope with an appropriate evacuation route by combining a smoke sensor and a temperature sensor.

≪Overview of node placement and safety confirmation method in tunnel≫
FIG. 1 is a diagram showing an overview of the arrangement of the sensor node 2 and a safety confirmation method. In FIG. 1, sensor nodes 2A, 2B, 2C,..., 2N and a plurality of terminals 4 are arranged in a tunnel 1. However, it shows that the worker who has the terminal 4 is gradually moving deep inside the tunnel 1.

The sensor nodes 2 </ _b > A to ₂ </ _b > N measure gas concentration (CO ₂ concentration and the like) and temperature, or detect smoke, and transmit the result (sensor information) to the terminal 4. The data transmitted from the sensor nodes 2A... 2N to the terminal 4 is not necessarily sensor information itself, but information indicating abnormality (hereinafter referred to as abnormality information) when the sensor information exceeds a predetermined threshold. Also good. Further, “2A... 2N” is a code used when specifying individual sensor nodes. When sensor nodes are collectively referred to, the code “2” is used like sensor node 2. .

  The terminal 4 is possessed by a worker for confirming safety in the tunnel 1, receives an RSSI (Received Signal Strength Indicator) from the sensor node 2, and uses the RSSI to detect the sensor node 2. The distance between is calculated. In addition, by receiving sensor information from the sensor node 2 and displaying it on the screen, the worker can confirm safety. The terminal 4 is realized by a notebook PC (Personal Computer) or a personal digital assistant (PDA). The information received by the terminal 4 from the sensor node 2 is a node ID, RSSI, and sensor information (including abnormality information).

  Next, a method for confirming safety in the tunnel 1 by a worker will be described. First, the worker throws the sensor node 2 </ b> A from the entrance at the left end of the tunnel 1 toward the tunnel 1. As a result, the sensor node 2A is arranged in the tunnel 1, for example, at a position several m from the entrance. Next, the worker confirms whether or not the terminal 4 has received the abnormality information from the sensor node 2A. If the terminal 4 has not received the abnormality information, the worker proceeds with the terminal 4 in the tunnel 1 to the back. Then, the terminal 4 receives the RSSI from the sensor node 2A, calculates the distance ds between the sensor node 2A from the RSSI, and approaches the sensor node 2A by the operator's hand while displaying it as necessary. . When the distance ds becomes equal to or less than the reference distance d0, a message to that effect is output. When the worker recognizes from the message that he / she has come close to the sensor node 2 </ b> A, the worker further throws the next sensor node 2 </ b> B toward the back of the tunnel 1. Therefore, after confirming that the abnormality information is not received from the sensor node 2B, the sensor node 2B is targeted and the tunnel 4 is advanced along with the terminal 4. The worker repeats the above procedure and confirms the safety up to the approach distance d in the tunnel 1.

  For example, when the terminal 4 receives abnormality information, RSSI, or the like from the sensor node 2B at a distance d1 from the entrance of the tunnel 1, it may be received directly or ad hoc communication via the sensor node 2A. May be received. The same applies to the case where the terminal 4 receives from the sensor node 2C at a position of distance d1 + d2 from the entrance of the tunnel 1, and so on. Further, when the terminal 4 receives the abnormality information, the worker stops further advancement and examines a countermeasure method.

  For example, ZigBee can be applied to the ad hoc communication used in the embodiment of the present invention. ZigBee is a standard for sensor networks in IEEE 802.15.4, and is specifically defined for a physical (PHY) layer and a MAC (Media Access Control) layer. And it has the features of low cost and low power consumption.

  FIG. 2 is a diagram showing an overview of an arrangement and safety confirmation method in which the relay node 3 is added to the sensor node 2. In FIG. 2, relay nodes 3A, 3B,..., 3N and a plurality of terminals 4 are linearly arranged in the tunnel 1, and sensor nodes 2 are arranged around the relay nodes 3A, 3B,. Is arranged. However, it shows that the worker who has the terminal 4 is gradually moving deep inside the tunnel 1.

  The sensor node 2 measures gas concentration and temperature, or detects smoke, and transmits the result (sensor information) to the terminal 4 by ad hoc communication via the relay node 3 belonging to the same group.

  The relay node 3 receives sensor information from the sensor nodes 3 belonging to the same group, and transmits the sensor information to the terminal 4. There are two possible methods for transmitting the sensor information. One is a method in which the relay node 3 periodically acquires sensor information of each sensor node 2 and transmits the group ID, node ID, and sensor information unique to the group to the terminal 4 as they are. On the other hand, when the relay node 3 periodically acquires sensor information of each sensor node 2 and the sensor information exceeds a threshold, a message indicating a group ID, a node ID, and an abnormality content is transmitted to the terminal 4 It is. Note that “3A... 3N” is a code used when specifying individual relay nodes, and when the relay nodes are generically referred to, the code “3” is used like the relay node 3. . As for data transmission / reception between the relay nodes 3, for example, in the case of the relay node 3B, it is set in advance that data is received from the relay node 3C (not shown) and transmitted to the relay node 3A. In this case, the received data is added with its own information (node ID, sensor information received from the sensor node 2 of the same group) and transmitted.

  The terminal 4 is owned by a worker for confirming safety in the tunnel 1, receives RSSI from the sensor node 2 via the relay node 3, and calculates the distance to the sensor node 2 based on the RSSI. To do. In addition, by receiving sensor information from the sensor node 2 and displaying it on the screen, the worker can confirm safety. For example, the group ID, node ID, temperature, and presence / absence of smoke are displayed in a list format. The terminal 4 is realized by a notebook PC or a portable information terminal.

  Next, a method for confirming safety in the tunnel 1 by a worker will be described. First, the worker distributes the plurality of sensor nodes 2 and one relay node 3A from the entrance of the tunnel 1 into the tunnel 1. As a result, the plurality of sensor nodes 2 and one relay node 3A are arranged in the tunnel 1, for example, at a position several m from the entrance. Then, a communication path to the terminal 4 is autonomously configured between each node, and sensor information from each sensor node 2 is collected in the terminal 4. For this reason, a communication path corresponding to the number of scattered sensor nodes 2 is configured, and the configuration information is stored in each sensor node 2 and relay node 3, thereby establishing wireless communication between nodes belonging to the same group. .

  Next, the worker checks whether or not the terminal 4 has received the abnormality information from the sensor node 2 via the relay node 3A. If the abnormality information has not been received, the worker proceeds with the terminal 4 in the tunnel 1 to the back. . Then, the terminal 4 receives the RSSI from the sensor node 2 via the relay node 3A, calculates the distance dm between the sensor node 2 having the maximum RSSI, and displays it as necessary. The sensor node 2 is approached by hand. When the distance dm is equal to or less than the reference distance d0, a message to that effect is output. When the worker recognizes from the message that he / she has come close to the sensor node 2 that has detected the maximum RSSI, the worker further goes to the inner side of the tunnel 1 and moves to the next plurality of sensor nodes 2 and relay nodes. Distribute 3B. Then, after confirming that no abnormality information has been received from the sensor node 2 via the relay node 3B, the sensor node 2 with the maximum RSSI is targeted, and the terminal 4 and the tunnel 1 are advanced. The worker repeats the above procedure and confirms the safety up to the approach distance d in the tunnel 1.

  For example, when the terminal 4 receives abnormality information, RSSI, or the like from the relay node 3B at a distance d1 from the entrance of the tunnel 1, it may be received directly or ad hoc communication via the relay node 3A. May be received. The same applies thereafter. Further, when the terminal 4 receives the abnormality information, the worker needs to consider a response method.

  Here, the node to which the data transfer from the sensor node 2 to the terminal 4 should be relayed differs depending on the types of nodes distributed as belonging to the same group. As shown in FIG. 2, when a plurality of sensor nodes 2 and relay nodes 3 are dispersed, the node to be relayed is specified as the relay node 3 by default regardless of the distance. In this case, the relay node 3 acquires data from the nearby sensor node 2 and transmits it to the terminal 4. Unlike FIG. 2, when only the sensor node 2 is dispersed, each sensor node 2 individually relays data transfer as needed. When only the relay node having the sensor function is distributed, the terminal 4 instructs one of the relay nodes to relay data transfer. The other relay nodes communicate with the nearest other node as the mere sensor node 2.

  The ad hoc communication is established and executed between the sensor nodes 2 and between the sensor node 2 and the terminal 4 in FIG. 1, and in FIG. 2, between the sensor nodes 2, between the sensor node 2 and the relay node 3, and each relay node 3. And between the relay node 3 and the terminal 4 and executed.

<< Node and terminal configuration >>
FIG. 3 is a diagram illustrating the configuration of the sensor node 2. The sensor node 2 includes a wireless communication unit 21, a sensor 22, a processing unit 23, and a storage unit 24. The wireless communication unit 21 has a function of wirelessly transmitting / receiving data generated by the sensor node 2 and a function of measuring RSSI. Specifically, it is realized by an antenna or a NIC (Network Interface Card). The sensor 22 has a function of measuring an external gas concentration and temperature or detecting smoke and outputting the result (sensor information) to the processing unit 23. The processing unit 23 acquires sensor information from the sensor 22, performs AD (Analog Digital) conversion, and then stores the function in the storage unit 24 and the sensor information into a data transfer format, so that other sensor nodes 2 and relay nodes 3 has a function to transmit. Specifically, it is realized by a CPU (Central Processing Unit) executing a program stored in a predetermined memory. The storage unit 24 stores data from the processing unit 23 and reads the stored data. Specifically, it is realized by a nonvolatile storage device such as a flash memory or a hard disk device.

  FIG. 4 is a diagram illustrating a configuration of the relay node 3. The relay node 3 includes a wireless communication unit 31, a processing unit 32, and a storage unit 33. The wireless communication unit 31 has a function of receiving data requests from other relay nodes 3 and terminals 4 and transmitting / receiving data received from the sensor nodes 2 wirelessly. Specifically, it is realized by an antenna or a NIC. The processing unit 32 acquires data from the sensor node 2 or the relay node 3 and accepts a function for storing the data in the storage unit 33 or a data request, arranges the data into a data transfer format, and transmits the data to another relay node 3 or terminal 4. It has the function to transmit to. Specifically, it is realized by the CPU executing a program stored in a predetermined memory. The storage unit 33 stores data from the processing unit 32 and reads the stored data. Specifically, it is realized by a nonvolatile storage device such as a flash memory or a hard disk device.

  FIG. 5 is a diagram illustrating a configuration of the terminal. The terminal 4 includes a wireless communication unit 41, a display unit 42, an input unit 43, a processing unit 44, and a storage unit 45. The wireless communication unit 41 has a function of wirelessly transmitting and receiving data to and from the sensor node 2 and the relay node 3. Specifically, it is realized by an antenna or a NIC. The display unit 42 has a function of displaying data from the processing unit 44. Specifically, it is realized by a liquid crystal display (LCD) or the like. The input unit 43 is operated by a worker to switch the screen displayed on the display unit 42, input items, and the like, and has a function of transferring data acquired along with the operation to the processing unit 44. Have. Specifically, it is realized by a pointing device such as a mouse or a keyboard. The processing unit 44 receives data from the wireless communication unit 41 and stores it in the storage unit 45, or reads out the data stored in the storage unit 45 and displays it on the display unit 42. Specifically, it is realized by the CPU executing a program stored in a predetermined memory. The storage unit 45 stores data from the processing unit 44 and reads the stored data. Specifically, it is realized by a nonvolatile storage device such as a flash memory or a hard disk device.

<< Data structure >>
FIG. 6 is a diagram illustrating a configuration of data stored in the storage unit of the sensor node. The storage unit 24 of the sensor node 2 stores a node ID 24A and a threshold value 24B. The node ID 24A is a code unique to the sensor node 2. The threshold value 24B is a threshold value related to sensor information (smoke, temperature, gas concentration, etc.) to be reported as abnormality information.

  FIG. 7 is a diagram illustrating a configuration of data stored in the storage unit of the relay node. The storage unit 33 of the relay node 3 stores a node ID 33A and a threshold value 33B. The node ID 33A is a code unique to the relay node 3. The threshold 33B is a threshold related to sensor information (smoke, temperature, gas concentration, etc.) to be reported as abnormality information when the relay node 3 has a sensor function. When the relay node 3 does not have a sensor function, the threshold 33B is invalid.

  FIG. 8 is a diagram illustrating a configuration of data stored in the storage unit of the terminal. The storage unit 45 of the terminal 4 stores a reference distance 45A and sensor node installation distance information 45B. FIG. 8A shows the reference distance 45A. The reference distance 45A is a predetermined value (d0) of the separation distance between the terminal 4 and the sensor node 2. When the terminal 4 approaches the sensor node 2 within the predetermined value (d0), the next sensor node 2 Is a threshold value for disposing further in the back.

  FIG. 8B shows the configuration of the sensor node installation distance information 45B. The sensor node installation distance information 45B includes a record including a node ID 45B1 and an installation distance 45B2. The node ID 45B1 is a code unique to the sensor node 2. The installation distance 45B2 is a distance from the entrance of the tunnel to the installation location of the sensor node 2. An example of specific setting values shown in FIG. 8B corresponds to FIG. dk (k = 1 to n) can be obtained by RSSI received by the terminal 4 from the sensor node 2 immediately after the sensor node 2 is thrown. When there is a relay node having a sensor function, installation distance information similar to the sensor node installation distance information 45B is set.

≪Details of processing≫
FIG. 9 is a flowchart showing an approach distance calculation process in the terminal 4. First, the terminal 4 sets a reference distance d0 with the sensor node 2 (S901). Specifically, the worker inputs the reference distance d0 to the input unit 43, the processing unit 44 acquires the input reference distance d0, and stores it in the storage unit 45 as the reference distance 45A. Next, the worker arranges the sensor node 2 (S902). For example, as shown in FIG. 1, by throwing the sensor node 2A from the entrance of the tunnel 1, the sensor node 2A is arranged at a predetermined position.

Subsequently, the terminal 4 receives the detection result of the abnormal state and the RSSI from the sensor node 2 arranged at a predetermined position (S903). There is no problem when one sensor node 2 exists as in the sensor node 2A shown in FIG. 1, but when there are a plurality of sensor nodes 2 belonging to the same group as shown in FIG. 2, the maximum RSSI is obtained. Receive values selectively. The RSSI is received by, for example, a predetermined circuit in the wireless communication unit 41 of the terminal 4 measuring the intensity of the received radio signal, A / D (Analog / Digital) converting a signal indicating the intensity, By outputting to the processing unit 44. If no abnormal state is detected from the detection result, the distance ds between the sensor node 2 and the terminal 4 is calculated from the received RSSI (S904). Specifically, the calculation is performed according to the following equation 1.

T− (R + Lp) = 10 * log {(4π / λ) * ds ² } Equation 1
T: Transmission power from terminal 4 (dBm)
R: received power (dBm) at terminal 4 = RSSI
Lp: Multipath loss (dBm)
d0: Optional reference distance (m)

Here, since Equation 1 shows the relationship between loss and distance when radio waves propagate in a free space free of obstacles, an index of ds is appropriately set according to the radio wave propagation environment (for example, 2 .0 to 4.0).

  When the terminal 4 receives the RSSI for the first time without moving from the position when the sensor node 2 is placed (S902), the node ID and the distance ds are accumulated (see FIG. 8B). Is stored in the storage unit 45 as sensor node installation distance information 45B. According to this, the approach distance d (= d1 + d2 + d3 +... + Dn) of the entire tunnel 1 can be finally obtained (see FIG. 1). If an abnormal state is detected from the detection result, the worker stops further advancement and examines a countermeasure.

  Next, the terminal 4 determines whether or not the distance ds between the sensor node 2 is equal to or less than the reference distance d0 (S905). When the distance ds is larger than the reference distance d0 (N in S905), nothing is displayed on the display unit 42, so the worker moves the terminal 4 toward the back in the tunnel 1 (S906). The terminal 4 waits for a predetermined time (S907) and then receives the RSSI from the sensor node 2 again (S903). As the terminal 4 moves and approaches the sensor node 2, the distance ds becomes closer to the reference distance d0. However, although the measurement error due to multipath is included in the distance ds, it is reliably determined that the distance ds is equal to or less than the reference distance d0 by appropriately setting the distance including the error with respect to the reference distance d0. Is possible.

  If the distance ds is less than or equal to the reference distance d0 (Y in S905), the terminal 4 displays a message indicating that on the display unit 42 (S908). If the worker refers to this message and continues the investigation (N in S909), the worker places the sensor node 2 again (S902). When the survey is to be ended (Y in S909), the approach distance calculation process is ended.

  FIG. 10 is a flowchart showing an abnormality information acquisition process. For example, as shown in FIG. 1, the sensor node 2 detects sensor information such as temperature and smoke, and transmits it to the terminal 4. The terminal 4 can collect abnormality information (fire, gas generation, etc.) on the intrusion route by ad hoc communication of the sensor node 2 installed up to the approach distance d in the tunnel 1. The terminal 4 can also determine the moving direction of the terminal 4 based on RSSI received from the sensor node 2 and guide the terminal 4 to a safe direction. Details will be described below.

  First, when the sensor node 2 is arranged, ad hoc communication is established between each sensor node 2 and the terminal 4 (S1001). For example, ZigBee can be applied to ad hoc communication. Next, the sensor node 2 acquires sensor information such as smoke, temperature, and gas concentration from the sensor 22 (S1002). Then, it is determined whether or not the acquired sensor information, which is smoke, temperature, or gas concentration, is equal to or higher than the threshold value 24B (S1003). If the sensor information is smaller than the threshold 24B (N in S1003), the sensor information is newly acquired (S1002). If the sensor information is greater than or equal to the threshold 24B (N in S1003), the sensor node 2 transmits abnormality information to the terminal 4 (S1004).

  Corresponding to the processing of the sensor node 2, the terminal 4 receives the abnormality information from the sensor node 2 (S1005). Then, the detected location of the received abnormality information is displayed on the display unit 42 (S1006). Specifically, the processing unit 44 refers to the sensor node installation distance information 45B stored in the storage unit 45, specifies the distance corresponding to the node ID included in the abnormality information, and determines the detected location according to the distance. By determining the position, a screen as shown in FIG. 11 is displayed. Next, the direction (evacuation direction) to be evacuated is instructed from the detected location of the abnormality information displayed on the screen (S1007). Specifically, an evacuation direction is instructed by displaying an arrow indicating a direction from a detection location in the tunnel to a tunnel entrance (in FIG. 11, entrances 5A and 5B of the tunnel 1A). When the tunnel is divided into multiple directions, the direction to the exit is instructed based on a preset entrance / exit database. This assumes, for example, evacuation from a location where smoke is detected. The worker moves according to the instruction displayed on the display unit 42 of the terminal 4.

  The terminal 4 that moves together with the worker receives the RSSI from the specific sensor node 2 and periodically repeats the reception a predetermined number of times, thereby detecting a temporal change in the RSSI and specifying the moving direction of the terminal 4 itself. (S1008). For example, if the RSSI increases with the passage of time, it means that it is moving in a direction approaching the sensor node 2 where the abnormality information is detected. In addition, if the RSSI decreases with time, the RSSI moves in a direction away from the sensor node 2. Then, by comparing with the direction to be evacuated instructed in S1007, it is determined whether or not the specified moving direction is correct (S1009). If the moving direction is not correct (N in S1009), the correct moving direction is instructed (S1010), and the own moving direction is specified (S1008). If the movement direction is correct (Y in S1009), the abnormality information acquisition process is terminated.

  In S1008, the terminal 4 has been described so as to identify the moving direction of the terminal 4 itself by detecting the temporal change in RSSI, but the distance between the sensor node 2 and the terminal 4 calculated from the RSSI is further described. In addition, the position of the terminal 4 is specified by the position of the sensor node 2 indicated by the sensor node installation distance information 45B, the positional relationship between the sensor node 2 and the terminal 4 detected by the abnormality information is grasped, and the direction to be evacuated or the dangerous direction May be clearly displayed. Further, the description of this processing has been made with respect to the linear arrangement of the sensor nodes 2 shown in FIG. 1, but the present invention can also be applied to the arrangement of the sensor nodes 2 and the relay nodes 3 shown in FIG.

  The embodiment of the present invention has been described above. In order to make each part of the sensor node 2 and the terminal 4 shown in FIG. 1 function, or each part of the sensor node 2, the relay node 3 and the terminal 4 shown in FIG. Therefore, a safety check according to the embodiment of the present invention is performed by recording a program executed by the processing unit (CPU) on a computer-readable recording medium, causing the computer to read and execute the recorded program. The method shall be realized. Note that the program may be provided to the computer via a network such as the Internet, or a semiconductor chip or the like in which the program is written may be incorporated in the computer.

  According to the embodiment of the present invention described above, the terminal 4 receives from the sensor node 2 that is thrown away or scattered in the tunnel 1 and refers to the displayed sensor information. Since the gas concentration can be known, the safety in the tunnel 1 can be confirmed safely and inexpensively. In addition, the sensor node 2 and the relay node 3 are grouped into the same group, and the sensor information from the sensor node 2 is received and displayed by the terminal 4 via the relay node 3, so that the area in the tunnel 1 is covered and detailed. Safety confirmation can be performed. And it becomes possible to guide an evacuation route using combinations other than a gas sensor (for example, a temperature sensor and a smoke sensor).

  Although the best mode for carrying out the present invention has been described above, the above embodiment is intended to facilitate understanding of the present invention and is not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and equivalents thereof are also included in the present invention.

It is a figure which shows the outline | summary of arrangement | positioning of a sensor node, and the safety confirmation method. It is a figure which shows the outline | summary of the arrangement | positioning which added the relay node to the sensor node, and the safety confirmation method. It is a figure which shows the structure of a sensor node. It is a figure which shows the structure of a relay node. It is a figure which shows the structure of a terminal. It is a figure which shows the structure of the data memorize | stored in the memory | storage part of a sensor node. It is a figure which shows the structure of the data memorize | stored in the memory | storage part of a relay node. It is a figure which shows the structure of the data memorize | stored in the memory | storage part of a terminal, (a) shows the reference distance 45A, (b) shows the structure of the sensor node installation distance information 45B. It is a flowchart which shows the calculation process of the approach distance in a terminal. It is a flowchart which shows the acquisition process of abnormality information. It is a figure which shows the example of a screen which displays the detection location of abnormality information.

Explanation of symbols

1 tunnel 2 sensor node 24 storage unit 24A node ID
3 relay node 4 terminal 45 storage unit 45A reference distance (predetermined value)
45B Sensor node installation distance information (installation position information)
45B1 Node ID
45B2 Installation distance 5 Exit

Claims (6)

A method of confirming safety in the predetermined space by a sensor node having a data communication relay function and an abnormal state detection function and a terminal that can wirelessly communicate with the sensor node and moves in the predetermined space. And
(1) In the predetermined space, the terminal receives a detection result and a received signal strength indication signal from the sensor node for a sensor node installed at a location separated from the terminal in the moving direction of the terminal. Then, if an abnormal state is not detected from the detection result, the distance from the sensor node is calculated based on the received signal strength display signal,
(2) When the calculated distance is less than or equal to the predetermined value, the terminal displays a message to that effect on the display unit,
(3) After the terminal displays the message, the target is a new sensor node installed at a location separated in the moving direction of the terminal,
(4) Repeat the processes (1) to (3),
A safety confirmation method characterized by that. The safety confirmation method according to claim 1,
Ad hoc communication is established between sensor nodes and between sensor nodes and terminals,
The sensor node is
Storing a node ID unique to the sensor node in the storage unit;
When an abnormal state in a predetermined space is detected, data related to the abnormal state is generated, the node ID is added to the data, and transmitted to the terminal by the ad hoc communication.
The terminal
Using the distance from the sensor node calculated based on the received signal strength display signal, the position of the sensor node in a predetermined space is specified, and the installation position information including the specified position and the node ID of the sensor node Is stored in the storage unit,
When data related to the abnormal state is received from the sensor node, the node ID added to the data is extracted, and the position of the sensor node corresponding to the node ID is determined by referring to the installation position information. A safety confirmation method characterized by identifying and displaying on the display section as a detection position of an abnormal state. The safety confirmation method according to claim 2,
The terminal
Store spatial information including the position of the entrance and exit of a predetermined space in the storage unit,
An arrow from the position of the sensor node displayed on the display unit to the position of the entrance is displayed as an evacuation direction,
While receiving the received signal strength display signal from the sensor node, the temporal change of the received received signal strength display signal is detected, and its own moving direction is identified according to the change,
Comparing the movement direction with the evacuation direction, and displaying a correct movement direction if they do not match, a safety confirmation method. A relay node having a data communication relay function, a sensor node having an abnormal state detection function, and the relay node and a terminal capable of wireless communication with the sensor node and moving in a predetermined space , the predetermined space. A method for confirming safety in
(1) In the predetermined space, the relay node and the plurality of sensor nodes that are set apart from the terminal in the moving direction of the terminal in the predetermined space are used as a target from the plurality of sensor nodes to the relay node. Via, receiving the detection result and the received signal strength display signal, if an abnormal state is not detected from the detection result, the distance from the sensor node is calculated based on the maximum received signal strength display signal,
(2) When the calculated distance is less than or equal to the predetermined value, the terminal displays a message to that effect on the display unit,
(3) After the terminal displays the message, the target is a new relay node and a plurality of sensor nodes installed at locations separated in the moving direction of the terminal,
(4) Repeat the processes (1) to (3),
A safety confirmation method characterized by that. The safety confirmation method according to claim 4,
Ad hoc communication is established between sensor nodes, between sensor nodes and relay nodes, between relay nodes, and between relay nodes and terminals.
The sensor node is
Storing a node ID unique to the sensor node in the storage unit;
When an abnormal state in a predetermined space is detected, data related to the abnormal state is generated, the node ID is added to the data, and transmitted to the terminal by the ad hoc communication.
The terminal
Using the distance from the sensor node calculated based on the maximum received signal strength display signal, the position of the sensor node in a predetermined space is specified, and the installation including the specified position and the node ID of the sensor node Store the location information in the storage unit,
When data related to the abnormal state is received from the sensor node, the node ID added to the data is extracted, and the position of the sensor node corresponding to the node ID is determined by referring to the installation position information. A safety confirmation method characterized by identifying and displaying on the display section as a detection position of an abnormal state. The safety confirmation method according to claim 5,
The terminal
Store spatial information including the position of the entrance and exit of a predetermined space in the storage unit,
An arrow from the position of the sensor node displayed on the display unit to the position of the entrance is displayed as an evacuation direction,
While receiving the received signal strength display signal from the sensor node, the temporal change of the received received signal strength display signal is detected, and its own moving direction is identified according to the change,
Comparing the movement direction with the evacuation direction, and displaying a correct movement direction if they do not match, a safety confirmation method.