JP4747009B2 - Wireless sensor network route construction method, data collection method, route reconstruction method, wireless sensor network system and program - Google Patents

Description

  The present invention relates to a wireless sensor network route construction method, a data collection method, a route reconstruction method, a wireless sensor network system, and a program, and more particularly, to a wireless sensor network route construction method and data for collecting sensor data from a plurality of wireless sensors. The present invention relates to a collection method, a route reconstruction method, a wireless sensor network system, and a program.

  In recent years, a large number of small wireless sensors with wireless communication functions that provide measured information such as temperature, humidity, sound, position, etc. as data are arranged at desired positions, and they are mutually linked to each wireless sensor. Wireless sensor networks that autonomously communicate with each other and with a predetermined device have attracted attention.

  As an example of such a wireless sensor network, a conventional environment monitoring system using ad hoc communication has been proposed (see, for example, Patent Document 1). In this conventional wireless sensor network system, a sensor module capable of ad hoc communication, which is provided at multiple locations in a scattered manner, includes a communication device and a sensor for measuring the concentration of environmental pollutants, and is obtained by ad hoc communication. By transmitting the measured value data of each sensor to the hot spot, the hot spot is transmitted to the environmental monitoring center via the Internet. The environmental monitoring center analyzes and manages the measurement data from each sensor.

  In this conventional wireless sensor network, a broadcast frame is transmitted to an adjacent wireless sensor (node), and a path is constructed between nodes to which a response is returned. In sensor data collection, sensor data is transmitted to a central environmental monitoring center via each node according to the route created above. In addition, when the radio wave condition between the wireless sensor nodes is bad and data collection fails, the route is updated in order to provide the optimum route each time.

  A remote data collection system using a wireless network is also known in the art (see, for example, Patent Document 2). This system described in Patent Document 2 wirelessly transmits monitoring measurement data from meters installed over a wide area such as electricity, gas, water, etc., from a slave unit to a master unit in a group, and only the master unit is a communication carrier. This is a wireless sensor network system that collectively transmits monitoring measurement data to the data collection center via the line.

JP 2004-178491 A JP 2002-2108080 A

  However, the conventional wireless sensor network system described in Patent Document 1 does not consider the radio wave state and distance between wireless sensor nodes, and thus has a problem that a route cannot be stably constructed. In addition, in the conventional ad hoc multi-hop communication of the wireless sensor network, a frame having the same content flows over the network many times during data collection. In multi-hop, each time sensor data is collected, the frame is returned to the center in a bucket relay manner, so that many relay frames flow. While the relay frame is flowing, other communication is not possible and the overall throughput is large. There is a problem of falling.

  In addition, if the radio wave condition between wireless sensor nodes is bad and data collection fails, the route is updated to provide the optimal route each time. Increases dramatically and more frames are sent into the network.

  In addition, the conventional network system described in Patent Document 2 has a problem that many unnecessary frames are transmitted between networks. The reason is that there is no restriction on the number of slave units or the number of hops for one group, so the number of slave units increases in one group and the number of hops increases. This is because a lot of relay frames flow by returning the frame to the bucket relay type. Similarly to the conventional wireless sensor network system described in Patent Document 1, when the radio wave condition continues to be bad, the path construction update rate dramatically increases, and more frames are transmitted into the network. There is also a problem of end.

  The present invention has been made in view of the above points, and by constructing a stable path based on the position information of the wireless sensor node and the radio field strength of each other, and further incorporating the grouping of paths, sensor data collection and path To provide a wireless sensor network route construction method, data collection method, route reconstruction method, wireless sensor network system, and program capable of eliminating an unnecessary frame at the time of reconstruction and providing an efficient ad hoc multi-hop protocol. With the goal.

In order to achieve the above object, a wireless sensor network path construction method according to the present invention includes a plurality of wireless sensor nodes that measure predetermined data and transmit the measured data as sensor data, each of which is scattered at arbitrary positions. A wireless sensor network path construction method provided with a base station node that collects sensor data from the plurality of wireless sensor nodes and performs network management,
A first step of disposing a plurality of wireless sensor nodes each having a different node ID at an arbitrary position; and a plurality of wireless sensor nodes stored in advance in a first storage unit of the base station node A second step of sequentially transmitting detection frames with a node ID as a transmission destination, and a wireless sensor node that has received a detection frame having a transmission destination of its own node ID among a plurality of wireless sensor nodes; A third step of transmitting a link notification frame as response information to the base station node using the radio field strength between the base station node and the base station node as ancillary information, and among the link notification frames received by the base station node, the radio field strength And the location information are the radio field strength and location information of the wireless sensor node that is the transmission source of the link notification frame within the specified value. The fourth step of registering as route information in the second storage unit and the first wireless sensor node and the second wireless device transmitted from the first wireless sensor node that has received the detection frame transmitted in the fifth step. link frames of the link notifies the radio wave strength and associated information between the sensor node, and a sixth step of the base station node via the second wireless sensor node receives, it received at the sixth step A seventh step of additionally registering the radio wave intensity and position information of the notification frame as route information in the second storage unit of the base station node, and based on the route information registered in the second storage unit of the base station node; Te, among a plurality of wireless sensor nodes, a plurality of first wireless sensor nodes connected directly to the base station node and each group parent wireless sensor nodes, those groups parent radio By the base station node to receive the parent setting request group having the ID information of one or more other second wireless sensor nodes within radio range of each group parent wireless sensor nodes for Nsanodo, each For each group parent wireless sensor node, one or two or more second wireless sensor nodes within the radio wave range and the group parent wireless sensor node are grouped into the same group, and the radio waves of the second wireless sensor node When another third wireless sensor node exists only within the range, the third wireless sensor node is also grouped into the same group as the second wireless sensor node within the same radio wave range. And the number of hops of multiple wireless sensor nodes grouped in the same group exceeds the first predetermined value. A ninth step of dividing the group, and a tenth step of dividing the group when the number of wireless sensor nodes grouped into one group exceeds a second predetermined value; And the path is constructed in a tree shape.

  In this invention, the base station node constructs a route of the plurality of wireless sensor nodes in a tree shape based on the position information of the plurality of wireless sensor nodes and the radio field strength of each other, and the route is directly connected to the base station node. It is possible to construct a route that divides a wireless sensor node to be connected into a group parent wireless sensor node and is divided into a group including one or more wireless sensor nodes connected to the group parent wireless sensor node in a tree shape.

Further, in order to achieve the above object, the present invention measures a predetermined data, a plurality of wireless sensor nodes that transmit the measurement data as sensor data, each arranged in a scattered manner at each arbitrary position, A base station node that collects sensor data from the plurality of wireless sensor data and performs network management is provided, and is a data collection method for a wireless sensor network in which a route is constructed by the route construction method of the present invention. ,
A first step of transmitting a data collection request frame from the base station node to the group parent wireless sensor node, and the group parent wireless sensor node receiving the data collection request receives sensor data from other wireless sensor nodes belonging to its own group. A third step of transmitting the sensor data collected from other wireless sensor nodes in the second step and the sensor data collected by the group parent wireless sensor node itself to the base station data; When the group parent wireless sensor node collects sensor data from other wireless sensor nodes belonging to its group in the second step, the base station node reconstructs the route until data collection fails a predetermined number of times. It is characterized in that the sensor data is collected by the same route without performing. In the present invention, route reconstruction is not performed until data collection fails a predetermined number of times, so the number of route reconstruction can be reduced.

  Further, in order to achieve the above object, the present invention measures a predetermined data, a plurality of wireless sensor nodes that transmit the measurement data as sensor data, each arranged in a scattered manner at each arbitrary position, A base station node that collects sensor data from the plurality of wireless sensor data and performs network management is provided, and is a route reconstructing method of a wireless sensor network in which a route is constructed by the route construction method of the present invention. When the base station node sends a data collection request frame to the group parent wireless sensor node and the group parent wireless sensor node collects sensor data from other wireless sensor nodes belonging to the group, data collection is performed. If the group parent wireless sensor no. If the sensor node cannot be collected from the wireless sensor node after the route change by the first step of changing the route of the wireless sensor node connected to the wireless sensor node and the route change within the same group by the first step, the wireless after the route change And a second step of performing path connection to another wireless sensor node in another group within the radio wave range of the sensor node. In the present invention, the base station node can reconstruct the route based on the position information of the plurality of wireless sensor nodes and the mutual radio field intensity.

In order to achieve the above object, the wireless sensor network system of the present invention is arranged in a scattered manner at each arbitrary position, measures predetermined data, and transmits a plurality of measurement data as sensor data. A wireless sensor network system comprising: a wireless sensor node; and a base station node that collects sensor data from a plurality of wireless sensor nodes and performs network management.
Based on the location information of multiple wireless sensor nodes and the radio field strength of each other, the path of multiple wireless sensor nodes is constructed in a tree shape, and the wireless sensor node that directly connects the path to the base station node is the group parent wireless sensor One or two or more wireless sensor nodes connected to the group parent wireless sensor node in a tree shape are grouped into one group, and a plurality of wireless sensor nodes grouped into the same group Route construction that divides the group when the number of hops exceeds the first predetermined value, and divides the group when the number of wireless sensor nodes grouped into one group exceeds the second predetermined value Means and each group parent wireless sensor node in the plurality of divided groups. Data collection means for collecting sensor data measured in sensor units and group parent wireless sensor nodes in units of groups, and data collection constructed by path construction means when data collection from the wireless sensor node fails a predetermined number of times Route reconstructing means for reconstructing a route including a wireless sensor node that has failed.

  In order to achieve the above object, the present invention provides a route construction program for causing a computer to execute the route construction method of the present invention, a data collection program for causing the computer to execute the data collection method of the present invention, and a route reconstruction of the present invention. A path reconstruction program for causing the method to be executed by a computer is included.

  According to the present invention, the base station node constructs a path of the plurality of wireless sensor nodes in a tree shape based on the position information of the plurality of wireless sensor nodes and the radio field strength of each other, and the path is configured as a base station node. By creating a route that divides a wireless sensor node directly connected to the group parent wireless sensor node into groups including one or more wireless sensor nodes connected to the group parent wireless sensor node in a tree shape, the sensor data It is possible to prevent frames with the same contents from flowing over the network many times during collection.

  In addition, according to the present invention, data is collected in units of groups instead of relaying frames to a large number of wireless sensor nodes in a bucket relay manner, so that the throughput of the network can be improved. Furthermore, according to the present invention, when the radio wave condition between the wireless sensor nodes is poor and data collection fails, the route is not updated in order to provide an optimum route each time. Since the frequency data collection is performed, even if the radio wave condition continues to be low, efficient ad hoc multi-hop communication is achieved by eliminating unnecessary frames for sensor data collection and reducing the number of path reconstructions. It becomes possible.

  Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a system configuration diagram of an embodiment of a wireless sensor network system according to the present invention. As shown in the figure, the present embodiment relates to a wireless sensor network for environmental monitoring using wireless sensor nodes, in a form in which the network is fixed and data is collected in the center, and the input device 1 such as a keyboard and the environment A wireless sensor node 3 that wirelessly transmits collected sensor data, a group parent wireless sensor node 4 when the transmission paths of the wireless sensor nodes are grouped, and a wireless sensor node 3 And a base station node 5 that controls the group parent wireless sensor node 4 and collects sensor data for managing the multi-hop wireless communication network. Here, although there are three groups, 2A, 2B, and 2C, the present invention is not limited to this.

  Each wireless sensor node 3 includes a sensor information storage unit 31 and a position information storage unit 32. The sensor information storage unit 31 is a memory table that can store up to N pieces of sensor information (N is a natural number of 1 or more). The position information storage unit 32 stores in advance position information of latitude / longitude of a place where the wireless sensor node of its own is installed.

  Each group parent wireless sensor node 4 includes a sensor information storage unit 41, a position information storage unit 42, and a lower path information storage unit 43, respectively. The sensor information storage unit 41 is a memory table that can store up to N pieces of sensor information. The position information storage unit 42 stores in advance position information of latitude / longitude of the place where the wireless sensor node 4 of its own is installed. The lower path information storage unit 43 is a memory table that stores lower path information of a group belonging to itself.

  The base station node 5 includes a configuration sensor node storage unit 51, a route information storage unit 52, a group information storage unit 53, and a radio wave intensity / position information storage 54. The configuration sensor node storage unit 51 is a memory table that stores in advance list information of wireless sensor nodes 3 to be measured. The route information storage unit 52 stores the wireless sensor node 3 as tree information. The group information storage unit 53 is a memory table that stores wireless sensor node ID information of tree information in units of groups. The radio wave intensity / position information storage 54 is a memory table that stores radio wave intensity and position information of the wireless sensor node 3 as a component.

  The base station node 5 includes a route construction unit 55, a data collection unit 56, and a route reconstruction unit 57. The route construction means 55 constructs a stable route in a tree shape based on the position information of the wireless sensor node 3 and the mutual radio field intensity. Next, the route information constructed in a tree shape is divided into groups. The data collection unit 56 collects data for each wireless sensor node divided into groups, and acquires sensor data from the group parent wireless sensor node 4. If the radio wave condition between the wireless sensor nodes is poor and data collection fails, the route reconstructing means 57 does not immediately reconstruct the route, and the M times that the sensor information storage units 31 and 41 respectively hold are the same route. To collect data. However, if it fails more than M times, the process proceeds to the process of the path reconstruction means 57.

  The route reconstruction means 57 performs route reconstruction within the group. If it is impossible to construct a route within the group, reconstruction is performed in order from the distance of the node within the range in which the node can transmit a frame. When there is no node that can be connected within the frame transmission range, the maintenance person 6 is notified of a message prompting that the frame is not measured.

  Next, the operation of the present embodiment will be described in detail. First, the route construction method will be described with reference to the flowchart of FIG. In order to collect sensor data, the wireless path of the wireless sensor node 3 is first constructed. First, the wireless sensor node 3 in which the node ID is set is arranged at the environmental data measurement site (step A1). Subsequently, a route construction instruction request is input from the input device 1 to the base station node 5 (step A2). The base station node 5 that has received the request for the path construction instruction determines whether or not there is a node registered in its own configuration sensor node storage unit 51 (step A3). The detection frames are transmitted one by one with the node ID registered in advance as the transmission destination (step A4).

  Each wireless sensor node 3 is assigned a node ID, and monitors whether or not a detection frame (link up notification) for its own node ID has been received (step A5), and receives a detection frame for its own node ID. In this case, the radio wave intensity and the position information are returned as attached information, and a link notification frame is returned as response information to the transmission source node (step A6). The link notification finally returns to the base station node 5 (step A7).

  The base station node 5 determines whether or not they are within the specified range based on the received radio field intensity and position information of each wireless sensor node 3 (step A8). If they are within the specified range, the route information The received information is stored in the storage unit 52 and the radio wave intensity / position information storage 54 (step A9). If the radio wave intensity and the position information exceed the specified range, the link-up cancellation process is performed and the connection is not established (step A10). In the same manner, the processing of steps A3 to A9 (or A10) is repeated to perform route construction for all wireless sensor nodes.

  Subsequently, the path construction of all the wireless sensor nodes is completed, and it is determined whether there is a node that is not linked up (step A11). The added wireless sensor is added to the route (step A12). When it is determined in step A11 that there is no node that is not linked up, or when the process of step A12 is completed, the route information is finally grouped (step A13).

  In this grouping, first, a wireless sensor node directly connected to the base station node 5 is assigned as a group parent wireless sensor node 4, and wireless sensor nodes connected to the group parent wireless sensor node 4 are assigned as the same group. At this time, if the number of hops (hierarchy) of wireless sensor nodes in one group exceeds X, the group is divided. However, when the number of nodes in the group is one, the group is not divided.

  When the number of wireless sensor nodes in one group exceeds a predetermined value L, the group is divided. For example, if the collection time of one group of sensor data is limited to less than one minute, and it takes 1 second per wireless sensor node to collect data, the maximum wireless sensor node per group described above The predetermined value L is 64.

  Next, the sensor data collection method of the present invention will be described with reference to the flowchart of FIG. First, the base station node 5 of FIG. 1 transmits a data collection request frame to the group parent wireless sensor node 4 (step B1). The group parent wireless sensor node 4 that has received the instruction frame collects data of the lower wireless sensor node 3 belonging to its own group (step B2).

  The wireless sensor node 3 that has received the data collection request frame stores the sensor data collected by the own node in the sensor information storage unit 31 (step B3). Subsequently, the wireless sensor node 3 transmits the collected sensor nodes to the group parent wireless sensor node 4 of the group to which the wireless sensor node 3 belongs, and is stored in the sensor information storage unit 41. This is performed for all wireless sensor nodes 3 (step B4).

  When the data collection of all the wireless sensor nodes 3 in the group is completed, the group parent wireless sensor node 4 sends the data collection response result to the base station node 5 (all the sensors in the group held in the sensor information storage unit 41). Data) frame is returned (step B5). While the group parent wireless sensor node 4 holds the sensor data in the sensor information storage unit 41, route reconstruction is not performed, and the base station node 5 collects data using the route created first (step B6).

  Next, route reconstruction according to the present invention when a wireless sensor node that cannot collect data within the above rules occurs will be described with reference to the flowchart of FIG. First, using a data collection request from the base station node 5 as a trigger, route reconstruction within the group is performed (step C1). If sensor data cannot be collected consecutively for a preset number of times after reconfiguration (when the target wireless sensor node to be reconfigured is a node that has not been linked up), it is assumed that route reconfiguration has failed. The station node 5 makes a determination (step C2, yes), and the base station node 5 causes the wireless sensor node to perform reconstruction in the order close to its own distance within a range in which the wireless sensor node can transmit frames (step C3).

  The wireless sensor node 3 in the group performs a connection process with an adjacent wireless sensor node 3 in another group, and determines whether there is a node that can be connected in a range where a message can be transmitted (step C4). If there is no node that can be connected, the process once returns to the base station node 5, and a message that prompts the base station node 5 to be excluded from the measurement target is notified to the maintenance person 6 (step C5).

  As described above, according to the present embodiment, wireless sensor networks are divided into groups, so that unnecessary frame transmission / reception at the time of sensor data collection is eliminated, and the number of times of path reconstruction is reduced, thereby reducing wireless sensor networks. Throughput can be improved, and efficient ad hoc multi-hop communication can be performed.

  Next, the operation of this embodiment will be described using a specific example. A description will be given of route construction means, data collection means, and route reconstruction when wireless sensor nodes are arranged as shown in FIG. First, route construction means will be described. The base station node 5 has ID = 0, and holds the configuration node ID (1 to 10) of the wireless sensor node 3 in the configuration sensor node storage unit 51 in advance.

  In route construction, one hop will be described with reference to FIG. In FIG. 6, the same components as those in FIG. First, the base station node 5 with ID = 0 transmits a detection frame to the wireless sensor node 3 with ID = 1 in the range where radio waves reach. The wireless sensor node 3 (ID = 1) that has received the detection frame links the radio wave intensity (the received electric field intensity of the radio wave from the base station node 5) and the position information (latitude / longitude information of the own node) as attached information. The up notification is responded to the base station node 5 (ID = 0). The base station node 5 (ID = 0) registers the radio wave intensity and position information of the wireless sensor node 3 (ID = 1) in the radio wave intensity / position information storage unit 54. The base station node 5 (ID = 0) performs the same process as described above for the other two nearest wireless sensor nodes 3 (ID = 4, ID = 9) through which radio waves reach.

  Next, with reference to FIG. 7, the path construction of a wireless sensor node that does not receive radio waves from the base station node 5 (ID = 0) will be described by taking the wireless sensor node 3 with ID = 2 as an example. In FIG. 7, the same components as those in FIGS. 5 and 6 are denoted by the same reference numerals. In FIG. 7, the base station node 5 transmits a detection frame with the wireless sensor node 3 of ID = 2 as the transmission destination ID. When the response of the link up notification cannot be received, the detection is requested to the connected wireless sensor node 3 (ID = 1). In this case, the base station node 5 transmits the detection frame to the wireless sensor node 3 (ID = 1) with the detection destination: ID = 2 and the detection source: ID = 1 to the wireless sensor node 3 (ID = 1).

  Wireless sensor node 3 (ID = 1) is detected by wireless sensor node 3 (ID = 2) as transmission destination: ID = 2, transmission source: ID = 1, detection destination: ID = 2, detection source: ID = 1. Send a frame. When the wireless sensor node 3 (ID = 2) receives the detection frame, the radio wave intensity (the received electric field intensity of the radio wave from the wireless sensor node 3 (ID = 1)) and the position information (latitude / longitude information of the own node) are attached. As information, a link-up notification is transmitted as a response to the wireless sensor node 3 (ID = 1) as the transmission source.

  When the wireless sensor node 3 (ID = 1) receives the link-up notification, the wireless sensor node 3 (ID = 1), transmission destination: ID = 0, transmission source: ID = 1, detection destination: ID = 2, detection source: ID = 1 are received. A link-up notification with the received radio wave intensity and position information as attached information is returned to the base station node 5 (ID = 0). When the base station node 5 (ID = 0) receives the link-up notification from the wireless sensor node 3 with ID = 1, the base station node 5 (ID = 0) receives it as attached information as a child node of the wireless sensor node 3 (ID = 1) in its internal memory. The radio field intensity and position information of the wireless sensor node 3 (ID = 2) are registered in the radio field intensity / position information storage 54. The same processing as described above is performed for the other wireless sensor nodes 3 (ID = 3, 5, 7, 10) to which radio waves from the base station node 5 (ID = 0) do not reach.

  The base station node 5 (ID = 0) requests detection of the wireless sensor node 3 (ID = 8) via the wireless sensor node 3 with ID = 4 and the wireless sensor node 3 with ID = 7. When the wireless sensor node 3 (ID = 8) receives the detection frame transmitted from the base station node 5 via the wireless sensor node 3 (ID = 4, 7), the radio wave intensity (from the wireless sensor node 3 (ID = 7)). The link up notification is returned to the base station node 5 (ID = 0) through the same route with the received electric field strength of the radio wave) and the position information (latitude / longitude information of the own node) as attached information.

  The base station node 5 (ID = 0) that has received this link-up notification has the radio field strength between the wireless sensor node 3 (ID = 7) and the wireless sensor node 3 (ID = 8) below the first threshold. And the distance between the wireless sensor node 3 (ID = 7) and the wireless sensor node 3 (ID = 8) is calculated based on the received position information, and the calculated distance is the second It is determined whether it is below the threshold value.

  When both the radio field intensity and the distance are below the respective threshold values, or the radio field intensity is below the first threshold value, it is determined that the path construction has failed, and the base station node 5 (ID = 0) The wireless sensor node 3 (ID = 10) is requested to detect the wireless sensor node 3 (ID = 8). When the wireless sensor node 3 (ID = 8) receives the detection frame transmitted from the base station node 5 via the wireless sensor node 3 (ID = 10), the radio wave intensity (the radio wave from the wireless sensor node 3 (ID = 10)). The link up notification is returned to the base station node 5 (ID = 0) through the same route with the received field strength of the received information and position information (latitude / longitude information of the own node) as auxiliary information.

  The base station node 5 (ID = 0) that has received this link-up notification has the radio field intensity and distance between the wireless sensor node 3 (ID = 10) and the wireless sensor node 3 (ID = 8) as the threshold values. If the wireless sensor node 3 is ID = 8, the wireless sensor node 3 with ID = 10 is stored in the route information storage unit 52 of the base station node 5 (ID = 0). to manage. In the same manner as described above, the base station node 5 (ID = 0) manages the wireless sensor node 3 with ID = 5 as an upper node of the wireless sensor node 3 with ID = 6. In this way, the route construction unit 55 of the base station node 5 creates route information having the tree structure shown in FIG. 8 and stores it in the route information storage unit 52.

  Next, the tree-structured network is divided into groups by the base station node 5 (ID = 0). As described above, there are the following three rules for group division.

  (1) A wireless sensor node directly connected to the base station node 5 is set as a parent wireless sensor node. Wireless sensor nodes below the parent wireless sensor node are assigned as the same group.

  (2) When the number of hops of wireless sensor nodes in one group exceeds X, the group is divided. However, when the number of nodes in the group is one, the group is not divided.

  (3) When the number of wireless sensor nodes in one group exceeds a predetermined value L (for example, 64), the group is divided.

  In accordance with the above rules, route information having a tree structure as shown in FIG. 9 is divided into groups. In FIG. 9, the same nodes as those in FIG. 8 are denoted by the same reference numerals. As shown in FIG. 9, the base station node 5 sets the wireless sensor node 3 (ID = 1, 4, 9) directly connected to the base station node 5 as the group parent wireless sensor node 4, and the group parent wireless sensor. The lower node ID information belonging to the group is transmitted to the node 4 (ID = 1, 4, 9) as a group parent setting request. Each group parent wireless sensor node 4 (ID = 1, 4, 9) that has received this group parent setting request is the parent of the group and holds the tree structure of the child nodes in the lower path information storage unit 43. To do.

  As a result, as shown in FIG. 9, the group parent wireless sensor node 4 (ID = 1) stores the wireless sensor nodes 3 with ID = 2 and ID = 3 in the lower-level route information storage unit 43 to form the group 2A. Then, the group parent wireless sensor node 4 (ID = 4) stores the wireless sensor node 3 with ID = 5 and ID = 7 in the lower path information storage unit 43 and further subordinate to the wireless sensor node 3 with ID = 5. The wireless sensor node 3 with ID = 6 is stored to form the group 2B, and the group parent wireless sensor node 4 (ID = 9) has ID = 9 in the lower path information storage unit 43 and ID = 9 in the lower order of ID = 9. 10. Each wireless sensor node 3 with ID = 8 is stored below ID = 10 to form a group 2C. The base station node 5 stores the group IDs = 1, 2, and 3 of the groups 2A, 2B, and 2C in the group information storage unit 53, and the IDs of the parent wireless sensor node 4 and the wireless sensor node 3 that constitute the group. For each group.

  Next, an embodiment of the data collection means will be described with reference to FIG. First, the base station node 5 (ID = 0) transmits a data collection request frame to the group parent wireless sensor node 4 (ID = 1) as indicated by 10-1. When the group parent wireless sensor node 4 (ID = 1) receives the data collection request frame, as shown by 10-2, the group parent wireless sensor node 4 (ID = 1) is based on the stored information in the lower path information storage unit 43. A data collection request frame is transmitted to the wireless sensor nodes 3 (ID = 2, 3) belonging to the own group including the node 4 (ID = 1).

  When the wireless sensor node 3 (ID = 2, 3) receives the data collection request frame, first, the sensor data measured by the wireless sensor node 3 (ID = 2, 3) is stored in its own sensor information storage unit 31, and then the group parent wireless sensor node 4 (ID = In response to 1), a response frame of sensor data is transmitted as indicated by 10-3.

  The group parent wireless sensor node 4 (ID = 1) that has received the response frame first stores the sensor data measured by itself in the sensor information storage unit 31, and then the sensor data of the lower node (ID = 2, 3) and the self The sensor data of (ID = 1) is transmitted as a response frame to the base station node 5 (ID = 0) as indicated by 10-4.

  If the radio wave condition between the wireless sensor nodes is bad and the data collection fails, the route is not immediately reconstructed, and the data is collected on the same route for M times held in the sensor information storage units 31 and 41. However, if it fails more than M times, the process proceeds to a path reconstruction process. This route reconstruction processing will be described with reference to FIG.

  Now, as shown in FIG. 11A, the wireless sensor node 3 (ID = 2) holds the sensor information storage unit 31 and the group parent wireless sensor node 4 (ID = 1) exceeds the wireless sensor node 3 more than N times. When data cannot be collected from (ID = 2), as shown in FIG. 5B, route reconstruction is performed in the group 2A of the group ID = 1 to which the group parent wireless sensor node 4 (ID = 1) belongs. I do. That is, as shown in FIG. 11B, the route restructuring means 57 of the base station node 5 transmits the wireless sensor node 3 (ID = 2) to the group parent wireless sensor node 4 (ID = 1). A setting is made to reconstruct the route as a lower node of the sensor node 3 (ID = 3).

  When route construction within the group 2A is impossible, the route reconstruction means 57 of the base station node 5 is in a range where the wireless sensor nodes (ID = 1, 2, 3) within the group 2A can transmit and receive frames. Among the wireless sensor nodes in the group, reconstruction is performed in the order from the closest distance to the own distance. When there is no wireless sensor node that can be connected to a range where the wireless sensor node (ID = 1, 2, 3) can transmit and receive a frame, a message prompting that the wireless sensor node is excluded from the measurement target is notified to the maintenance person 6.

  The present invention is not limited to the above-described embodiments and examples, and includes a computer program that causes a computer to execute route construction, data collection, route reconstruction, and the like performed by the base station node 5. .

It is a system configuration figure of one embodiment of a wireless sensor network system of the present invention. It is a flowchart of one embodiment of the route construction method of the present invention. It is a flowchart of one embodiment of a data collection method of the present invention. It is a flowchart explaining the path | route reconstruction method when the wireless sensor node which cannot collect data within the rule of this invention generate | occur | produces. It is a figure which shows the example of arrangement | positioning of the wireless sensor node to which the route construction method of this invention, the data collection method, and the route reconstruction method are applied. It is explanatory drawing about 1 hop of the route construction method of this invention. It is explanatory drawing of an example of the path | route construction method of the wireless sensor node which the electromagnetic wave from the base station node (ID = 0) of this invention does not reach. It is a figure which shows the path | route information of the tree structure created by the path | route construction means of the base station node by this invention. It is a figure which shows the example which divided the path | route information of the tree structure into groups by this invention. It is explanatory drawing of one Example of the data collection method of this invention. It is explanatory drawing of one Example of the route reconstruction method of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Input device 2A, 2B, 2C Group 3 Wireless sensor node 4 Group parent wireless sensor node 5 Base station node 31, 41 Sensor information storage part 32, 42 Position information storage part 43 Lower path information storage part 51 Configuration sensor node storage part 52 Route information storage unit 53 Group information storage unit 54 Radio wave intensity / position information storage 55 Route information construction means 56 Data collection means 57 Route reconstruction means

Claims (7)

A plurality of wireless sensor nodes that measure predetermined data and transmit the measured data as sensor data are arranged at arbitrary positions, and the sensor data is collected from the plurality of wireless sensor nodes. A wireless sensor network path construction method provided with a base station node for performing network management,
A first step of disposing the plurality of wireless sensor nodes, each having a different node ID, at the arbitrary position;
A second step of sequentially transmitting detection frames with the node IDs of the plurality of wireless sensor nodes stored in advance in the first storage unit of the base station node as destinations;
Among the plurality of wireless sensor nodes, the wireless sensor node receiving the detection frame whose own node ID is a transmission destination links the position information of itself and the radio field intensity between the base station node as attached information. A third step of transmitting a notification frame to the base station node as response information;
Of the link notification frames received by the base station node, the radio wave intensity and position information are the radio wave intensity and position information of the wireless sensor node that is the transmission source of the link notification frame within a specified value. A fourth step of registering as route information in the second storage unit of the station node;
For the first wireless sensor node having a node ID that cannot receive the link notification frame, the radio field intensity and the position information are registered in the second storage unit adjacent to the first wireless sensor node. A fifth step of requesting the second wireless sensor node to transmit a detection frame whose destination is the node ID of the first wireless sensor node;
And the fifth step in which is transmitted from the first wireless sensor node that received the detection frames transmitted in radio wave strength and the attached information between the position information of the self and the second wireless sensor node A sixth step in which the base station node receives a link notification frame via the second wireless sensor node;
A seventh step of additionally registering the radio field intensity and position information of the link notification frame received in the sixth step as path information in a second storage unit of the base station node;
Based on the route information registered in the second storage unit of the base station node, wherein among the plurality of wireless sensor nodes, each group parent wireless multiple first wireless sensor nodes connected directly to the base station node and a sensor node, a group having the base station nodes for those groups parent wireless sensor node ID information of one or more other second wireless sensor nodes within radio range of each group parent wireless sensor node By receiving the parent setting request, grouping is performed so that each group parent wireless sensor node has one or more second wireless sensor nodes within the radio wave range and the group parent wireless sensor node as the same group. And another third wireless sensor node is only within the radio wave range of the second wireless sensor node. When standing is an eighth step of performing grouping to the same group as the third wireless sensor nodes said second wireless sensor nodes within the same radio range,
A ninth step of dividing the group when the number of hops of the plurality of wireless sensor nodes grouped into the same group exceeds a first predetermined value;
A tenth step of dividing the group when the number of the wireless sensor nodes grouped into one group exceeds a second predetermined value, and constructing a path in a tree structure, To build a route for wireless sensor networks. A plurality of wireless sensor nodes that measure predetermined data and transmit the measured data as sensor data are arranged in scattered points at arbitrary positions, and the sensor data is collected from the plurality of wireless sensor data. In addition, a base station node that performs network management is provided, and a data collection method for a wireless sensor network in which a route is constructed by the route construction method according to claim 1,
A first step of transmitting a data collection request frame from the base station node to the group parent wireless sensor node;
The group parent wireless sensor node that has received the data collection request collects sensor data from the other wireless sensor nodes belonging to its own group, and the other wireless sensor node in the second step. And a third step of transmitting the sensor data collected by the group parent wireless sensor node itself to the base station data, wherein the base station node is configured to send the group data in the second step. When the parent wireless sensor node collects sensor data from other wireless sensor nodes belonging to its own group, it does not perform route reconstruction until the data collection fails a predetermined number of times, and collects sensor data on the same route. A data collection method for a wireless sensor network. A plurality of wireless sensor nodes that measure predetermined data and transmit the measured data as sensor data are arranged in scattered points at arbitrary positions, and the sensor data is collected from the plurality of wireless sensor data. In addition, a base station node that performs network management is provided, and a route reconstructing method for a wireless sensor network in which a route is constructed by the route constructing method according to claim 1,
When transmitting a data collection request frame from the base station node to the group parent wireless sensor node and collecting the sensor data from the other wireless sensor nodes belonging to the group by the group parent wireless sensor node, A first step of changing a route of a wireless sensor node connected to the group parent wireless sensor node within the group when data collection has failed a predetermined number of times;
If sensor nodes cannot be collected from the wireless sensor node after the route change even if the route within the same group is changed in the first step, within another group within the radio wave range of the wireless sensor node after the route change. And a second step of establishing a path connection to another wireless sensor node of the wireless sensor network. A plurality of wireless sensor nodes that are arranged in arbitrary positions at scattered points, measure predetermined data, and transmit the measurement data as sensor data;
A wireless sensor network system including a base station node that collects the sensor data from the plurality of wireless sensor nodes and performs network management,
The base station node
Based on the positional information of the plurality of wireless sensor nodes and the radio wave strength of each other, the routes of the plurality of wireless sensor nodes are constructed in a tree shape, and the wireless sensor nodes that are directly connected to the base station node are grouped. One or two or more wireless sensor nodes connected as a parent wireless sensor node in a tree shape to the group parent wireless sensor node are grouped into one group, and a plurality of the aforementioned grouped into the same group When the number of hops of the wireless sensor node exceeds the first predetermined value, the group is divided. When the number of the wireless sensor nodes grouped into one group exceeds the second predetermined value, the group A path construction means for dividing
Data collection means for collecting sensor data measured in group units from each group parent wireless sensor node in the plurality of divided groups, the wireless sensor node of the group and the group parent wireless sensor node;
A route reconstructing unit configured to reconstruct a route including the wireless sensor node that has failed in data collection, which is constructed by the route construction unit when data collection from the wireless sensor node has failed a predetermined number of times. A featured wireless sensor network system. A plurality of wireless sensor nodes that measure predetermined data and transmit the measured data as sensor data are arranged at arbitrary positions, and the sensor data is collected from the plurality of wireless sensor nodes. A route construction program for causing a computer to perform route construction of a wireless sensor network provided with a base station node that performs network management,
On the computer,
A first frame that is stored in advance in the first storage unit of the base station node and that sequentially transmits detection frames with the node IDs of the plurality of wireless sensor nodes each having a different node ID set as a transmission destination. Steps,
Among the plurality of wireless sensor nodes, the wireless sensor node that has received the detection frame whose transmission destination is its own node ID transmits its own position information and the radio field intensity between the base station node as attached information. The second step of receiving the link notification frame, and the radio sensor node that is the transmission source of the link notification frame within the link notification frame in which the radio wave intensity and the position information are within a specified value. A third step of registering the radio field strength and position information of the base station node as route information in a second storage unit of the base station node;
For the first wireless sensor node having a node ID that cannot receive the link notification frame, the radio field intensity and the position information are registered in the second storage unit adjacent to the first wireless sensor node. A fourth step of requesting the second wireless sensor node to transmit a detection frame having the node ID of the first wireless sensor node as a transmission destination;
And the fourth transmitted from the first wireless sensor node that received the detection frame transmitted in step, radio wave strength and the attribute information between the position information of the self and the second wireless sensor node A fifth step of receiving a link notification frame via the second wireless sensor node;
A sixth step of additionally registering the radio field intensity and position information of the link notification frame received in the fifth step as path information in a second storage unit of the base station node;
Based on the route information registered in the second storage unit of the base station node, wherein among the plurality of wireless sensor nodes, each group parent wireless multiple first wireless sensor nodes connected directly to the base station node and a sensor node, a group having the base station nodes for those groups parent wireless sensor node ID information of one or more other second wireless sensor nodes within radio range of each group parent wireless sensor node By receiving the parent setting request, grouping is performed so that each group parent wireless sensor node has one or more second wireless sensor nodes within the radio wave range and the group parent wireless sensor node as the same group. And another third wireless sensor node is only within the radio wave range of the second wireless sensor node. When standing is a seventh step of performing grouping to the same group as the third wireless sensor nodes said second wireless sensor nodes within the same radio range,
An eighth step of dividing the group when the number of hops of the plurality of wireless sensor nodes grouped into the same group exceeds a first predetermined value;
When the number of the wireless sensor nodes grouped into one group exceeds a second predetermined value, the ninth step of dividing the group is executed. program. A plurality of wireless sensor nodes that measure predetermined data and transmit the measured data as sensor data are arranged in scattered points at arbitrary positions, and the sensor data is collected from the plurality of wireless sensor data. In addition, a base station node for performing network management is provided, and a data collection program for causing a computer to perform data collection of a wireless sensor network in which a route is constructed by the route construction method according to claim 1,
In the computer,
A first step of transmitting a data collection request frame from the base station node to the group parent wireless sensor node;
The group parent wireless sensor node that has received the data collection request collects the sensor data collected from the other wireless sensor nodes belonging to the group and the sensor data collected by the group parent wireless sensor node itself. The second step of collecting from the parent wireless sensor node is sequentially executed, and route data is not reconstructed until data collection fails a predetermined number of times, and sensor data is collected by the same route. Data collection program. A plurality of wireless sensor nodes that measure predetermined data and transmit the measured data as sensor data are arranged in scattered points at arbitrary positions, and the sensor data is collected from the plurality of wireless sensor data. A wireless sensor network path reconstruction program that includes a base station node that performs network management and causes a computer to perform path reconstruction of a wireless sensor network that has been constructed by the path construction method according to claim 1. Because
When transmitting a data collection request frame from the base station node to the group parent wireless sensor node and collecting the sensor data from the other wireless sensor nodes belonging to the group by the group parent wireless sensor node, A first step of changing a route of a wireless sensor node connected to the group parent wireless sensor node within the group when data collection has failed a predetermined number of times;
If sensor nodes cannot be collected from the wireless sensor node after the route change even if the route within the same group is changed in the first step, within another group within the radio wave range of the wireless sensor node after the route change. A wireless sensor network route reconstructing program, comprising: performing a second step of performing route connection to another wireless sensor node.

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