JP2011205583A - Data collection terminal, and data collection system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a data collection terminal and system, efficiently collecting data from nodes of a sensor network.SOLUTION: In a sensor network including a slave station for transmitting data obtained by measurement of a sensor, this data collection terminal 110 is equipped with: a positioning part 114 configured to measure the position of the data collection terminal 110; and a communication part 112 configured to determine whether the data collection terminal 110 is present in a predetermined position, based on the position measured by the positioning part 114, request the slave station to transmit data when the data collection terminal 110 is present at the predetermined position, and receive data transmitted by the slave station as a response to the request.

Description

  The present invention relates to a data collection terminal that collects data measured by a sensor, and a data collection system.

  The sensor network dynamically connects the slave station, relay station, and master station (hereinafter referred to as “node”) with sensors, and relays the data measured by the slave station sensor. The data is relayed by the station and transmitted from the slave station to the master station (see Patent Documents 1 to 3).

JP 2009-199545 A JP 2009-218922 A Japanese Patent Laid-Open No. 11-232578

  By the way, wireless communication is not possible between nodes that are separated from each other by a distance that allows wireless communication. In this case, in order to collect data from a node that cannot communicate wirelessly, a data collection terminal that collects data is mounted on a vehicle and approaches the node to a distance that enables wireless communication, You need to collect data from the node.

  However, the data collection systems disclosed in Patent Documents 1 to 3 have a problem that data cannot be efficiently collected from the nodes. For example, in the data collection systems disclosed in Patent Documents 1 to 3, the data collection terminal broadcasts a search signal for searching for a node capable of communication in a predetermined cycle while moving. The data collection terminal needs to receive data from the node after receiving a response from the node that has received the search signal. For this reason, the data collection terminal has a problem that the time for receiving the data is short and the data cannot be collected efficiently from the node.

  The present invention has been made in view of the foregoing points, and an object of the present invention is to provide a data collection terminal and a data collection system that can efficiently collect data from a node of a sensor network.

  The present invention has been made to solve the above problems, and in a sensor network including a node that transmits data measured by a sensor, a positioning unit that measures the position of the terminal, and the positioning unit performs positioning. Based on the position, it is determined whether or not the terminal is in a predetermined position, and when the terminal is in the predetermined position, the node is requested to transmit the data, and the request And a communication unit that receives the data transmitted by the node as a response to the data collection terminal.

  In the present invention, the communication unit requests the node to transmit the data through a plurality of channels, and receives the data transmitted by the node as a response to the request through the plurality of channels. This is a characteristic data collection terminal.

  Further, the present invention is characterized in that the communication unit requests the node to transmit the new data in the order measured by the sensor, and receives the new data transmitted by the node as a response to the request. It is a data collection terminal.

  In the present invention, the communication unit requests the node to transmit the continuous data in the order measured by the sensor, and receives the continuous data transmitted by the node as a response to the request. This is a characteristic data collection terminal.

  Further, according to the present invention, the communication unit requests the node to transmit the data selected according to the moving speed of the terminal from the data measured by the sensor, and as a response to the request. A data collection terminal for receiving the selected data transmitted by the node.

  In the data collection terminal, the communication unit may request the node to transmit the data not received by the communication unit from the data measured by the sensor. is there.

  Moreover, this invention is a data collection system characterized by including a data collection terminal and the mobile body which mounts the said data collection terminal and moves.

  According to the present invention, the data collection terminal requests the node to transmit data when the terminal is at a predetermined position. That is, the data collection terminal requests a node capable of communication from a predetermined position of the terminal itself to transmit data. For this reason, the data collection terminal does not need to broadcast the search signal, and the time for receiving the data becomes long. Therefore, the data collection terminal can efficiently collect the data from the nodes of the sensor network.

It is a figure which shows the 1st example of a structure of a sensor network. It is a figure which shows the 2nd example of a structure of a sensor network. It is a figure which shows the 3rd example of a structure of a sensor network. It is a figure which shows the 4th example of a structure of a sensor network. 3 is a diagram illustrating an example of communication between slave stations 200a to 200c and a data collection terminal 110 provided in a mobile unit 100. FIG. 2 is a block diagram showing a configuration of a mobile unit 100 and a configuration of a data collection terminal 110. FIG. 4 is a table showing a communication start position and a communication end position for each slave station 200. It is a sequence diagram which shows operation | movement of communication with the data collection terminal 110 and the sub_station | mobile_unit 200 when the data collection terminal 110 does not use a positional information. FIG. 11 is a sequence diagram illustrating an operation of communication between the data collection terminal 110 and the slave station 200 when the data collection terminal 110 uses position information. It is a figure which shows operation | movement with the data management system 700, the data collection terminal 110, and the sub_station | mobile_unit 200. FIG. It is a figure which shows the communication in the some channel in the data collection terminal 110 with which the mobile body 100 was equipped, and the sub_station | mobile_unit 200a. It is a sequence diagram which shows the 1st example of operation | movement of communication with the data collection terminal 110 and the sub_station | mobile_unit 200 in the case of communicating on a some channel. It is a sequence diagram which shows the 2nd example of operation | movement of communication with the data collection terminal 110 and the substation 200 in the case of communicating on a plurality of channels. It is a sequence diagram which shows the operation | movement of communication with the data collection terminal 110 and the sub_station | mobile_unit 200a in case the data collection terminal 110 receives new data in the order which the sensor measured. It is a figure which shows the received data in case data collection terminal 110 receives new data in the order which the sensor measured for every communication. It is a sequence diagram which shows the operation | movement of communication with the data collection terminal 110 and the sub_station | mobile_unit 200 in case the data collection terminal 110 receives the continuous data in the order which the sensor measured. It is a figure which shows the received data in case data collection terminal 110 receives the continuous data in the order which the sensor measured for every communication. It is a figure which shows the example of the relationship between the speed of the mobile body 100, and an acquisition data space | interval. It is a figure which shows the example of the "summary" of the data which the data collection terminal 110 collected. It is a figure which shows the relationship between the moving speed of the mobile body 100, and the number of received data.

[First Embodiment]
A first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a configuration example of a sensor network. The sensor network includes slave stations 200a to 200e (hereinafter, the slave stations may be collectively referred to as “slave station 200”) as nodes. Note that the sensor network may include more slave stations 200.

  The configuration of the sensor network dynamically changes according to instructions from the master station that is a node. Here, the master station may move or may be installed at a predetermined position. In the following, it is assumed that the sensor network is configured in advance in any of the configurations shown in FIGS. Note that the configurations shown in FIGS. 1A to 1D are examples.

  FIG. 1A shows a first example of a sensor network configuration. The sensor network includes slave stations 200a to 200e. Here, the slave station 200 includes sensors (not shown), and is installed at a predetermined position. For example, the slave station 200 may be a distribution facility that distributes power.

  Further, as an example, the sensor provided in the slave station 200a measures the temperature and humidity of the slave station 200a at a predetermined time. Then, the slave station 200a stores data measured by the sensor (hereinafter referred to as “data”) for each time measured by the sensor. The same applies to the slave stations 200b to 200e.

  Further, when the slave station 200a is requested to transmit data, the slave station 200a wirelessly transmits data for each time measured by the sensor to the data collection terminal 110 as a response to the request (data transmission). The same applies to the slave stations 200b to 200e. It is assumed that the distance that the slave stations 200a to 200e can communicate wirelessly is determined in advance.

  The data collection system includes a mobile object 100 and a data collection terminal 110. The moving body 100 includes a data collection terminal 110 that collects data and moves. The moving body 100 may be a vehicle, for example. Then, the mobile unit 100 approaches the slave station 200a up to a distance where the data collection terminal 110 and the slave station 200a can communicate wirelessly (road-to-vehicle communication). In addition, the mobile unit 100 approaches the slave stations 200b to 200e in the same manner.

  Here, the mobile unit 100 may include a relay station that relays communication between the slave station 200 and the data collection terminal 110.

  The data collection terminal 110 provided in the moving mobile unit 100 collects data by communicating with the slave station 200 wirelessly while moving with the mobile unit 100.

  Note that the mobile unit 100 does not have to stop moving while the data collection terminal 110 performs wireless communication with the slave station 200. Further, the normal route (route) along which the moving body 100 moves may not be a fixed dedicated route.

  Moreover, the mobile body 100 (vehicle etc.) may be moving for purposes other than the purpose of collecting data. That is, even when the mobile unit 100 happens to move near the slave station 200 for purposes other than the purpose of collecting data, the data collection terminal 110 may collect data from the slave station 200. Further, there may be a plurality of data collection terminals 110 and mobile objects 100. In this case, instead of a certain mobile unit 100, when another mobile unit 100 approaches the slave station 200, the data collection terminal 110 mounted on the approached mobile unit 100 receives data from the slave station 200. You may receive it.

  FIG. 1B shows a second example of the sensor network configuration. Only differences from the first example shown in FIG. 1A will be described. The sensor network illustrated in FIG. 1B includes relay stations 300a and 300b. Relay station 300a is installed at a predetermined first position, and relays communication between slave stations 200a to 200c and data collection terminal 110. Similarly, the relay station 300b is installed at a predetermined second position, and relays communication between the slave stations 200d to 200e and the data collection terminal 110. Hereinafter, the relay stations may be collectively referred to as “relay station 300”. Note that the sensor network may include more relay stations 300.

  FIG. 1C shows a third example of the configuration of the sensor network. This third example is an example in which the first example shown in FIG. 1A and the second example shown in FIG. 1B coexist. Relay station 300a is installed at a predetermined first position, and relays communication between slave stations 200a to 200c and data collection terminal 110. On the other hand, in the third example, the slave stations 200d and 200e transmit the data for each time measured by the sensor to the data collection terminal 110 wirelessly without using the relay station.

  FIG. 1D shows a fourth example of the sensor network configuration. Only differences from the second example shown in FIG. 1B will be described. The sensor network illustrated in FIG. 1D includes a master station 400. The master station 400 is installed at a predetermined third position. It is assumed that the configuration of the sensor network illustrated in FIG. 1D is determined in advance according to an instruction from the master station 400.

  The master station 400 includes a communication device slave station 500. The communication device slave station 500 relays communication between the relay stations 300a and 300b and the communication device parent station 600 described later. Here, the distance that the communication device slave station 500 can communicate may be longer than the distance that the slave station 200 and the relay station 300 can communicate. In the fourth example shown in FIG. 1D, the mobile unit 100 includes a communication device master station 600. Communication device master station 600 relays communication between communication device slave station 500 and data collection terminal 110.

  Thus, the sensor networks shown in FIGS. 1A to 1D have different node hierarchies. Since the most basic configuration of the node is the first example shown in FIG. 1A, the first example shown in FIG. 1A will be described below. And if the hierarchy of a node is changed, the data collection system in this embodiment is applicable also to any example shown to FIG.

  FIG. 2 shows an example of communication (road-to-vehicle communication) between the slave stations 200a to 200c and the data collection terminal 110 provided in the mobile unit 100. Here, it is assumed that the mobile unit 100 includes the data collection terminal 110, approaches the slave station 200a, and has moved to the position A. And the mobile body 100 moves in order of position AG. The mobile unit 100 may further move and approach the slave station 200d and the slave station 200e to a distance where the slave station 200d and the slave station 200e can communicate with the data collection terminal 110 (see FIG. 1A). .

  Here, it is assumed that the distance from the position A to the slave station 200a is equal to or less than the distance at which the slave station 200a can communicate wirelessly. The same applies to positions B and C. Therefore, the data collection terminal 110 can communicate with the slave station 200a at the positions A to C. Hereinafter, the position A at which the data collection terminal 110 starts communication with the slave station 200a may be referred to as “communication start position”. Further, the position C at which the data collection terminal 110 ends communication with the slave station 200a may be hereinafter referred to as “communication end position”.

  Similarly, it is assumed that the distance from the position C to the slave station 200b is equal to or less than the distance at which the slave station 200b can communicate wirelessly. The same applies to positions D and E. Therefore, the data collection terminal 110 can communicate with the slave station 200b at the positions C to E. Hereinafter, the position C at which the data collection terminal 110 starts communication with the slave station 200b may be referred to as “communication start position”. Further, the position E at which the data collection terminal 110 ends communication with the slave station 200b may be hereinafter referred to as “communication end position”.

  Similarly, it is assumed that the distance from the position E to the slave station 200c is equal to or less than the distance at which the slave station 200c can communicate wirelessly. The same applies to the positions F and G. Therefore, the data collection terminal 110 can communicate with the slave station 200c at the positions E to G. Hereinafter, the position E at which the data collection terminal 110 starts communication with the slave station 200c may be referred to as “communication start position”. Further, the position G at which the data collection terminal 110 ends communication with the slave station 200c may be hereinafter referred to as “communication end position”.

  Thus, since the data collection terminal 110 moves with the mobile body 100, the time during which communication with each of the slave stations 200a to 200c is possible is limited. For example, when the communicable distance is 200 [m] and the moving speed of the mobile unit 100 is 20 [km / h], the time during which each slave station can communicate with the data collection terminal 110 is about 36. Seconds. In the same movement route as in this case, for example, when the communicable distance is 200 [m] and the moving speed of the moving body 100 is 40 [km / h], each slave station receives the data collection terminal 110. The time that can be communicated with is about 18 seconds. Then, the data collection terminal 110 collects data within a limited predetermined time during which communication with each of the slave stations 200a to 200c is possible.

  Here, for example, if communication is performed according to “ZigBee (registered trademark)” which is a typical sensor network standard of the 2.4 [GHz] band, wireless communication is possible at a communication speed of 250 [kbps]. . Further, if the sensor provided in the slave station 200a measures 24 points (every hour) of temperature and humidity per day, and if the measured temperature and humidity is data of 4 [bytes], it is per month. Is 2880 [bytes] (96 [bytes / day]).

  For example, when the slave station 200a transmits a data amount of 64 [bytes] per 100 [ms], the slave station 200a sends the data amount to the data collection terminal 110 that moves at a speed of 40 [km / h]. Data of “11520 (= 18 × 10 × 64) [bytes]” can be transmitted. This data amount 11520 [bytes] corresponds to the data amount of data (temperature and humidity) measured by the sensor for about four months.

  Therefore, in this case, in order to collect all data from the slave station 200a without losing data, the data collection terminal 110 receives (collects) all data measured by the slave station 200a at least once every four months. There is a need to. The same applies to the slave stations 200b and 200c.

Next, the configuration of the data collection terminal 110 will be described.
FIG. 3 is a block diagram showing the configuration of the mobile unit 100 and the configuration of the data collection terminal 110. The moving body 100 includes a drive unit 120 and a data collection terminal 110. The driving unit 120 moves the moving body 100 by the driving force.

  The data collection terminal 110 is provided in the mobile unit 100 and moves together with the mobile unit 100 to collect data from the slave station 200 of the sensor network. The data collection terminal 110 includes a control unit 111, a communication unit 112, a storage unit 113, and a positioning unit 114.

  The positioning unit 114 measures the position of the data collection terminal 110 at a predetermined cycle. The positioning unit 114 may measure the position of the data collection terminal 110 based on radio waves from an artificial satellite (for example, a GPS satellite). The positioning unit 114 may measure the position of the data collection terminal 110 (triangulation) based on the strength of radio waves. The positioning unit 114 then outputs information indicating the position of the data collection terminal 110 (hereinafter referred to as “position information”) to the control unit 111. Note that the method by which the positioning unit 114 measures the position of the data collection terminal 110 is not limited to the above.

  The storage unit 113 stores data received by the communication unit 112. The storage unit 113 stores a communication start position and a communication end position for each slave station 200. In FIG. 4, the communication start position and communication end position for each slave station 200 are shown in a table. As shown in FIG. 2, the communication start position for the slave station 200a is “position A”. Further, the communication end position with respect to the slave station 200a is “position C”. Similarly, the communication start position for the slave station 200b is “position C”. The communication end position for the slave station 200b is “position E”. Similarly, the communication start position for the slave station 200c is “position E”. The communication end position for the slave station 200c is “position G”.

  These communication start position and communication end position are measured in advance as positions where communication with the slave station 200 is possible and stored in the storage unit 113 in advance.

  Returning to FIG. 3, the description of the data collection terminal 110 will be continued. Position information is input from the positioning unit 114 to the control unit 111. The control unit 111 compares the predetermined position with the position information, and determines whether or not the data collection terminal 110 is at the predetermined position.

  Here, the predetermined position is a communication start position, a communication end position, and a position connecting the communication start position and the communication end position. For example, the slave station 200a is associated with predetermined positions A to C (see FIGS. 2 and 4). Similarly, the slave station 200b is associated with predetermined positions C to E. Similarly, the slave station 200c is associated with predetermined positions E to G.

  When the data collection terminal 110 is in a predetermined position, the control unit 111 causes the communication unit 112 to transmit a signal requesting the slave station 200 to transmit data to the slave station 200. Hereinafter, a signal for requesting the slave station 200 to transmit data may be referred to as a “data request”.

  The communication unit 112 performs wireless communication with the slave stations 200a to 200c under the control of the control unit 111. Here, the communication unit 112 transmits a data request to the slave station 200a under the control of the control unit 111. Then, the communication unit 112 receives the data transmitted by the slave station 200a as a response to the transmitted data request. Further, the communication unit 112 stores the received data in the storage unit 113 for each time measured by a sensor included in the slave station 200a. The same applies to the slave stations 200b and 200c.

Next, the communication operation of the data collection terminal 110 will be described.
FIG. 5 is a sequence diagram illustrating an operation of communication between the data collection terminal 110 and the slave station 200 when the data collection terminal 110 does not use position information.

  Here, FIG. 5 is a diagram shown for comparison with the communication operation of “when the data collection terminal 110 uses location information” shown in FIG. 6 described later. The data collection terminal 110 executes a communication operation shown in FIG. 6 to be described later in order to collect data more efficiently than the communication operation shown in FIG.

  When the data collection terminal 110 does not use the location information, the communication unit 112 broadcasts a search signal for searching for the slave station 200 that can communicate with the broadcast unit at a predetermined period according to the control of the control unit 111 ( Step S1).

  Here, it is assumed that the mobile unit 100 includes the data collection terminal 110, approaches the slave station 200a, and has moved to the position A (see FIG. 2). Further, since the communication unit 112 transmits a search signal at a predetermined cycle in accordance with the control of the control unit 111, it is assumed that the search signal is transmitted from the position A even when moving to the position A (step S2). ). Then, the slave station 200 a that has received the search signal transmits a response to the communication unit 112. Further, the communication unit 112 outputs the response received from the slave station 200a to the control unit 111. Thereby, communication between the data collection terminal 110 and the slave station 200a is established (communication establishment) (step S3).

  It is assumed that the moving body 100 has moved to the position B. Since communication with the slave station 200a is established, the control unit 111 causes the communication unit 112 to transmit a data request to the slave station 200a (step S4). Then, as a response to the request, the slave station 200a transmits data for each time measured by the sensor to the data collection terminal 110 (data transmission). And the communication part 112 receives the data, and memorize | stores the received data in the memory | storage part 113 for every time which the sensor measured (step S5).

  It is assumed that the moving body 100 has moved to the position C. On the other hand, it is assumed that the slave station 200a transmits a signal indicating that the transmission of data is completed (hereinafter referred to as “transmission completion signal”) to the data collection terminal 110. Then, the communication unit 112 outputs the transmission completion signal received from the slave station 200a to the control unit 111 (step S6). Since the transmission completion signal has been input, the control unit 111 causes the communication unit 112 to transmit a signal for ending communication with the slave station 200 (hereinafter referred to as “communication end signal”) to the slave station 200a. Thereby, the communication between the data collection terminal 110 and the slave station 200a ends (communication end) (step S7).

  The communication unit 112 transmits a search signal from the position C under the control of the control unit 111 (step S8). Then, the slave station 200b that has received the search signal transmits a response to the communication unit 112. Then, the communication unit 112 outputs the response received from the slave station 200b to the control unit 111. Thereby, communication between the data collection terminal 110 and the slave station 200b is established (communication establishment) (step S9).

  It is assumed that the moving body 100 has moved to the position D. Since communication with the slave station 200b is established, the control unit 111 causes the communication unit 112 to transmit a data request to the slave station 200b (step S10). Then, as a response to the request, the slave station 200b transmits data for each time measured by the sensor to the data collection terminal 110 (data transmission). The communication unit 112 receives the data, and stores the received data in the storage unit 113 for each time measured by the sensor (step S11).

  It is assumed that the moving body 100 has moved to the position E. On the other hand, it is assumed that the slave station 200b transmits a transmission completion signal to the data collection terminal 110. Then, the communication unit 112 outputs the transmission completion signal received from the slave station 200b to the control unit 111 (step S12). Since the transmission completion signal has been input, the control unit 111 causes the communication unit 112 to transmit a communication end signal to the slave station 200b. Thereby, the communication between the data collection terminal 110 and the slave station 200b ends (step S13).

  The communication unit 112 transmits a search signal from the position E under the control of the control unit 111 (step S14). Then, the slave station 200c that has received the search signal transmits a response to the communication unit 112. Then, the communication unit 112 outputs the response received from the slave station 200c to the control unit 111. Thereby, communication between the data collection terminal 110 and the slave station 200c is established (communication establishment) (step S15).

  In the subsequent steps, the data collection terminal 110 similarly repeats the operations shown in steps S2 to S7 (steps S8 to S13).

  On the other hand, FIG. 6 shows a sequence diagram of the communication operation between the data collection terminal 110 and the slave station 200 when the data collection terminal 110 uses the position information. Then, in order to collect data more efficiently than the communication operation illustrated in FIG. 5, the data collection terminal 110 executes the communication operation illustrated in FIG. 6.

  The control unit 111 acquires the communication start position and communication end position for each slave station 200 from the storage unit 113 (see FIG. 4).

  Here, it is assumed that the mobile unit 100 includes the data collection terminal 110, approaches the slave station 200a, and has moved to the position A (see FIG. 2). In addition, the positioning unit 114 measures the position of the data collection terminal 110 at a predetermined period and outputs position information to the control unit 111. Then, the control unit 111 acquires position information from the positioning unit 114 and determines the slave station 200 associated with the acquired position information.

  Since there is the data collection terminal 110 at the predetermined position “position A”, the control unit 111 transmits a data request from the communication unit 112 to the slave station 200a associated with the “position A” ( Step Sa1). Then, as a response to the request, the slave station 200a transmits data for each time measured by the sensor to the data collection terminal 110 (data transmission). The communication unit 112 receives the data, and stores the received data in the storage unit 113 for each time measured by the sensor (step Sa2).

  Assume that the moving body 100 moves to the position B together with the data collection terminal 110. Since the data collection terminal 110 is at the predetermined position “position B”, the control unit 111 of the data collection terminal 110 transmits data from the communication unit 112 to the slave station 200 a associated with the “position B”. A request is transmitted (step Sa3). Then, as a response to the request, the slave station 200a transmits data for each time measured by the sensor to the data collection terminal 110 (data transmission). The communication unit 112 receives the data, and stores the received data in the storage unit 113 for each time measured by the sensor (step Sa4).

  Assume that the moving body 100 moves to the position C together with the data collection terminal 110. Since there is the data collection terminal 110 at the predetermined position “position C”, the control unit 111 of the data collection terminal 110 transmits data from the communication unit 112 to the slave station 200a associated with the “position C”. A request is transmitted (step Sa5). Then, as a response to the request, the slave station 200a transmits data for each time measured by the sensor to the data collection terminal 110 (data transmission). The communication unit 112 receives the data, and stores the received data in the storage unit 113 at each time measured by the sensor (step Sa6).

  Since the data collection terminal 110 is at the predetermined position “position C”, the control unit 111 causes the communication unit 112 to transmit a data request to the slave station 200b associated with the “position C” ( Step Sa7). Then, as a response to the request, the slave station 200b transmits data for each time measured by the sensor to the data collection terminal 110 (data transmission). The communication unit 112 receives the data, and stores the received data in the storage unit 113 for each time measured by the sensor (step Sa8).

  Assume that the moving body 100 moves to the position D together with the data collection terminal 110. Since the data collection terminal 110 is at the predetermined position “position D”, the control unit 111 of the data collection terminal 110 transmits data from the communication unit 112 to the slave station 200b associated with the “position D”. A request is transmitted (step Sa9). Then, as a response to the request, the slave station 200b transmits data for each time measured by the sensor to the data collection terminal 110 (data transmission). The communication unit 112 receives the data, and stores the received data in the storage unit 113 for each time measured by the sensor (step Sa10).

  Assume that the moving body 100 moves to the position E together with the data collection terminal 110. Since the data collection terminal 110 is at the predetermined position “position E”, the control unit 111 of the data collection terminal 110 transmits data from the communication unit 112 to the slave station 200b associated with the “position E”. A request is transmitted (step Sa11). Then, as a response to the request, the slave station 200b transmits data for each time measured by the sensor to the data collection terminal 110 (data transmission). The communication unit 112 receives the data, and stores the received data in the storage unit 113 for each time measured by the sensor (step Sa12).

  Since the data collection terminal 110 is at the predetermined position “position E”, the control unit 111 causes the communication unit 112 to transmit a data request to the slave station 200c associated with the “position E” ( Step Sa13). Then, as a response to the request, the slave station 200c transmits data for each time measured by the sensor to the data collection terminal 110 (data transmission). The communication unit 112 receives the data, and stores the received data in the storage unit 113 for each time measured by the sensor (step Sa14).

  As described above, the data collection terminal 110 does not need to broadcast the search signal by using the position information, and the time for receiving the data becomes longer. Therefore, the data collection terminal 110 is more efficient than the communication operation shown in FIG. Data can be collected.

  Also, as shown in FIG. 6, in the present embodiment, it is not essential to execute the communication end process (transmission / reception of the transmission completion signal and the communication end signal) (see comparison with FIG. 5). 5 and 6, the response (ACK) in the lower layer is not shown, but the gist of the present embodiment is not changed even if the response (ACK) is not shown.

  As described above, in the sensor network including the slave station 200 that transmits the data measured by the sensor, the data collection terminal 110 of the data collection system includes the positioning unit 114 that positions the data collection terminal 110 and the positioning unit 114. Based on the measured position, it is determined whether or not the data collection terminal 110 is at a predetermined position. If the data collection terminal 110 is at a predetermined position, the slave station 200 is requested to transmit data. And a communication unit 112 that receives data transmitted by the slave station 200 as a response to the request.

  Thereby, the data collection terminal 110 of the data collection system can efficiently collect data from the slave station 200 of the sensor network. For example, the data collection terminal 110 does not need to broadcast the search signal, and the time for receiving the data is increased, so that the data can be efficiently collected from the slave station 200 of the sensor network.

  Further, when there are a plurality of slave stations 200 (nodes) in the sensor network, the data collection terminal 110 transmits a data request to the slave station 200 that has become communicable due to the approach, and the slave station 200 as a response to the data request Receives data sent by. Thereby, since data is not transmitted from the slave station 200 to which no data request is transmitted, the data collection terminal 110 does not cause congestion even when performing wireless communication with respect to the plurality of slave stations 200. Data can be efficiently collected from the slave station 200 of the sensor network.

[Second Embodiment]
A second embodiment of the present invention will be described in detail with reference to the drawings. In the second embodiment, the data management system 700 described later outputs information indicating unacquired data to the data collection terminal 110 and instructs the data collection terminal 110 to receive the data indicated by the information. Different from the first embodiment. Only the differences from the first embodiment will be described below.

  The data collection system further includes a data management system 700. A configuration of the data management system 700 will be described. The data management system 700 includes a communication unit 710, a determination unit 720, an instruction unit 730, and a storage unit 740. The communication unit 710 receives data collected by the data collection terminal 110 and causes the storage unit 740 to store the received data.

  The determination unit 720 determines data that is not acquired by the own system (hereinafter, may be referred to as “unacquired data”). Here, the unacquired data is missing data that is not stored in the storage unit 740 among the continuous data “n”. That is, unacquired data may be data that is not received by the communication unit 112 of the data collection terminal 110.

  Then, the instruction unit 730 instructs the data collection terminal 110 to receive (complement) the unacquired data. For example, the data collection system transmits information indicating unacquired data to the data collection terminal 110 via the communication unit 710, thereby receiving “unacquired data” indicated by the information at the data collection terminal 110. Let

  The data collection terminal 110 moves with the mobile unit 100 and receives data not acquired by the data management system 700 from the slave station 200a based on an instruction from the data management system 700 (information indicating unacquired data). To do. Further, the data collection terminal 110 stores the received data in the data management system 700.

Next, communication operations between the slave station 200, the data collection terminal 110, and the data management system 700 will be described.
FIG. 7 shows operations of the data management system 700, the data collection terminal 110, and the slave station 200a. Here, it is assumed that the data collection terminal 110a is provided in the moving body 100a. Further, it is assumed that the data collection terminal 110b is provided in the moving body 100b. Hereinafter, the data collection terminals 110a and 110b may be collectively referred to as “data collection terminal 110”.

  Since the operation described in the present embodiment is the same regardless of which of the slave stations 200a to 200e is used, this embodiment will be described using the slave station 200a as an example. In addition, data measured by the sensor of the slave station 200a at time n (n is an integer of 0 to 23) is denoted as “n”.

  First, it is assumed that the storage unit 740 of the data management system 700 stores data “1”, “2”, “3”, “4”, “6”, “8” as an example. Further, it is assumed that the slave station 200a stores data “5” to “9” as an example for each time measured by the sensor. Then, the data collection terminal 110a receives the data “7” from the slave station 200a and returns to the position where the data management system 700 is installed (step Sb1). Further, the data collection terminal 110 a transmits the received data “7” to the communication unit 710 of the data management system 700. (Step Sb2).

  Then, the communication unit 710 receives the data “7” collected by the data collection terminal 110 and stores it in the storage unit 740. Furthermore, the determination unit 720 determines unacquired data. Here, the determination unit 720 determines the continuity of the data “n”, and determines the missing data “5” and “after 9” as unacquired data (step Sb3).

  Then, based on the determination by the determination unit 720, the instruction unit 730 instructs the data collection terminals 110a and 110b to receive the unacquired data “5” and “9 and later”. For example, the instruction unit 730 transmits information indicating unacquired data to the data collection terminal 110 via the communication unit 710 so as to receive the unacquired data “5” and “after 9”. The data collection terminals 110a and 110b are instructed (step Sb4). Here, any of the data collection terminals 110a and 110b that have received the instruction may collect the data. Hereinafter, as an example, it is assumed that the data collection terminal 110b collects unacquired data.

  The data collection terminal 110b moves together with the mobile unit 100b and approaches the slave station 100a to a distance that allows communication with the slave station 100a (step Sb5). Since the data collection terminal 110b is instructed to receive the data “5” and “9 and later”, the slave station 200a transmits the data “5”, “9”, and “10”. A data request is transmitted to 200a (step Sb6).

  Then, since the slave station 200a is requested to transmit the data “5”, “9”, and “10”, the stored data “5” and “9” are transmitted to the data collection terminal 110b. (Data transmission).

  Further, since the slave station 200a does not store the data “10” requested to be transmitted, the data “10” is used as information indicating that the slave station 200a does not store the data “10”. It transmits to the collection terminal 110b.

  Then, the data collection terminal 110b receives data “5”, “9”, and “no 10” including data not acquired by the data management system 700 from the slave station 200a (step Sb7).

  The data collection terminal 110b returns to the position where the data management system 700 is installed. Further, the data collection terminal 110 a transmits data “5” and “9” of the received data to the communication unit 710 of the data management system 700. Then, the communication unit 710 receives the data “5” and “9” collected by the data collection terminal 110b and stores them in the storage unit 740 (step Sb8).

  In this way, the data collection terminal 110 and the data management system 700 collect unacquired data.

  As described above, in the sensor network including the slave station 200 that transmits the data measured by the sensor, the data management system 700 determines the data not acquired by the system from the data measured by the sensor. 720 and the data collection terminal 110 that receives data from the slave station 200, output information indicating data not acquired by the own system, and receive data not acquired by the own system based on the information. An instruction unit 730 for instructing the data collection terminal 110.

  Thereby, the data collection terminal 110 and the data management system 700 can efficiently collect data from the slave station 200 of the sensor network. That is, the data management system 700 causes the data collection terminal 110 to receive unacquired data that has not been received by the data collection terminal 110 from the data measured by the sensor. Can be collected efficiently.

  Further, the data management system 700 determines the continuity of the data “n” and causes the data collection terminal 110 to collect the missing data. Thereby, the data collection terminal 110 and the data management system 700 can efficiently collect the missing data from the slave station 200 of the sensor network.

[Third Embodiment]
A third embodiment of the present invention will be described in detail with reference to the drawings. In the third embodiment, the communication unit 112 of the data collection terminal 110 requests the slave station 200 to transmit data through a plurality of channels, and the data transmitted by the slave station 200 as a response to the request is transmitted through the plurality of channels. The point of reception is different from the first and second embodiments. Only the differences from the first and second embodiments will be described below.

  FIG. 8 shows communication on a plurality of channels between the data collection terminal 110 and the slave station 200a provided in the mobile unit 100. The communication unit 112 (see FIG. 3) of the data collection terminal 110 communicates using a plurality of channels. Here, as an example, it is assumed that the plurality of channels are channel J, channel K, and channel L. Similarly, the slave station 200a communicates with channel J, channel K, and channel L. Different data for each channel may be transmitted and received. Note that the communication unit 112 and the slave station 200a of the data collection terminal 110 may include more channels.

  Then, the data collection terminal 110 communicates with the slave station 200a using the plurality of channels in parallel (simultaneously) at the positions A to C. Further, the data collection terminal 110 communicates with the slave station 200b (not shown in FIG. 8, refer to FIG. 2) using the plurality of channels in parallel (simultaneously) at the positions C to E. Further, the data collection terminal 110 communicates with the slave station 200c (not shown in FIG. 8, refer to FIG. 2) using a plurality of channels in parallel (simultaneously) at the positions E to G.

Next, the communication operation of the data collection terminal 110 will be described.
FIG. 9 is a sequence diagram showing a first example of the communication operation between the data collection terminal 110 and the slave station 200 in the case where communication is performed using a plurality of channels.

  Since the data collection terminal 110 is located at the predetermined position “position A”, the control unit 111 (see FIG. 3) sends the slave unit 200 a associated with the “position A” from the communication unit 112. A data request is transmitted on channel J, channel K, and channel L (step Sb1). Then, as a response to the request, the slave station 200a transmits data for each time measured by the sensor to the data collection terminal 110 through the channel J, the channel K, and the channel L (data transmission). The communication unit 112 receives the data, and stores the received data in the storage unit 113 for each time measured by the sensor (step Sb2).

  In the subsequent steps, the data collection terminal 110 similarly repeats the operations shown in steps Sb1 and Sb2.

  If there is a position where communication with two or more slave stations 200 is possible in parallel (simultaneously), the data collection terminal 110 may communicate as shown in FIG. 10 from that position. . FIG. 10 is a sequence diagram showing a second example of the operation of communication between the data collection terminal 110 and the slave station 200 when communication is performed using a plurality of channels.

  The control unit 111 (see FIG. 3) causes the slave station 200a associated with a predetermined position to transmit a data request from the communication unit 112 through the channel J. Further, the control unit 111 causes the communication unit 112 to transmit a data request through the channel K to the slave station 200b associated with the predetermined position. Furthermore, the control unit 111 transmits a data request from the communication unit 112 to the slave station 200c associated with the predetermined position through the channel L (step Sc1).

  Then, as a response to the request, the slave station 200a transmits data for each time measured by the sensor to the data collection terminal 110 via the channel J (data transmission). Similarly, the slave station 200b transmits data for each time measured by the sensor to the data collection terminal 110 via the channel K. Similarly, the slave station 200c transmits data for each time measured by the sensor to the data collection terminal 110 via the channel L. The communication unit 112 receives the data, and stores the received data in the storage unit 113 for each time measured by the sensor (step Sc2).

  In subsequent steps Sc3 to 6, the data collection terminal 110 repeats the operations shown in steps Sc1 and 2 in the same manner.

  In addition, the control unit 111 (see FIG. 3) causes the slave station 200a associated with a predetermined position to transmit a data request from the communication unit 112 through the channel J. Further, the control unit 111 may cause the communication unit 112 to transmit a data request via the channels K and L to the slave station 200b associated with the predetermined position (step Sc7).

  Then, as a response to the request, the slave station 200a transmits data for each time measured by the sensor to the data collection terminal 110 via the channel J (data transmission). Similarly, the slave station 200b transmits data for each time measured by the sensor to the data collection terminal 110 through the channels K and L. The communication unit 112 receives the data, and stores the received data in the storage unit 113 for each time measured by the sensor (step Sc8).

  In subsequent steps Sc9 and 10, the data collection terminal 110 may repeat the operations shown in steps Sc7 and 8 in the same manner.

  As described above, the communication unit 112 of the data collection terminal 110 requests the slave station 200 to transmit data through a plurality of channels, and receives the data transmitted by the slave station 200 as a response to the request through the plurality of channels. To do.

  Thereby, the data collection terminal 110 and the data management system 700 can efficiently collect data from the slave station 200 of the sensor network. For example, the data collection terminal 110 can efficiently collect data by increasing the amount of data received within a predetermined time.

  Further, the data collection terminal 110 and the data management system 700 can efficiently collect data from the slave station 200 of the sensor network in a dense area of the slave stations 200 without causing congestion in wireless communication.

[Fourth Embodiment]
A fourth embodiment of the present invention will be described in detail with reference to the drawings. In the fourth embodiment, the data collection terminal 110 requests the slave station 200 to transmit new data in the order measured by the sensor, and receives the new data transmitted by the slave station 200 as a response to the request. 1 to 3rd embodiment is different. Only the differences from the first to third embodiments will be described below.

  FIG. 11 is a sequence diagram showing an operation of communication between the data collection terminal 110 and the slave station 200a when the data collection terminal 110 receives new data in the order measured by the sensor. Here, the slave station 200a stores data “1” to “4” in the order measured by the sensor. That is, in this case, data “4” is the latest data. The slave station 200a may store data in a storage unit (not shown) having a queue structure.

  The control unit 111 (see FIG. 3) of the data collection terminal 110 has the data collection terminal 110 at a predetermined position “position A”. The data request is transmitted from the communication unit 112. Here, the control unit 111 causes the slave unit 200a to request the communication unit 112 to transmit new data in the order measured by the sensor (step Sd1). Then, as a response to the request, the slave station 200a transmits ACK to the data collection terminal 110 (step Sd2).

  Further, the slave station 200a transmits the latest data “4” in the order measured by the sensor among the data for each time measured by the sensor to the data collection terminal 110 as a response to the request (data transmission). And the communication part 112 receives the data, and memorize | stores the received data in the memory | storage part 113 for every time which the sensor measured (step Sd3). Further, the control unit 111 (see FIG. 3) causes ACK (response) to be transmitted from the communication unit 112 to the slave station 200a (step Sd4).

  Assume that the moving body 100 moves to the position B together with the data collection terminal 110. The control unit 111 (see FIG. 3) of the data collection terminal 110 has the data collection terminal 110 at a predetermined position “position B”. The data request is transmitted from the communication unit 112. Here, the control unit 111 causes the slave unit 200a to request the communication unit 112 to transmit new data in the order measured by the sensor (step Sd5). Then, as a response to the request, the slave station 200a transmits ACK to the data collection terminal 110 (step Sd6).

  Further, the slave station 200a transmits the latest data “4” next to the latest data “4” in the order measured by the sensor among the data for each time measured by the sensor to the data collection terminal 110 as a response to the request. (Data transmission) And the communication part 112 receives the data, and memorize | stores the received data in the memory | storage part 113 for every time which the sensor measured (step Sd7). Further, the control unit 111 (see FIG. 3) causes ACK (response) to be transmitted from the communication unit 112 to the slave station 200a (step Sd8).

  In subsequent steps, the data collection terminal 110 may repeat the operations shown in steps Sd1 to 4 (steps Sd5 to 8) in the same manner.

  Note that the slave station 200a may stop transmitting data if it cannot receive an ACK (response) from the data collection terminal 110 even if it transmits data a predetermined number of times (for example, three times). Good (steps Sd11 to 13). In addition, even if the data collection terminal 110 transmits a data request a predetermined number of times and cannot receive an ACK (response) from the slave station 200, the data collection terminal 110 may stop transmitting the data request.

  FIG. 12 shows received data for each communication when the data collection terminal 110 receives new data in the order measured by the sensor. Here, the received data is data received by the data collection terminal 110. It is assumed that the data collection terminal 110 and the slave station 200a have already performed communication before the “first communication” shown in FIG.

  In the first communication, it is assumed that the storage unit 113 (see FIG. 3) stores data “1” to “3” that are received data until the previous communication. The slave station 200a stores data “1” to “5” in the order measured by the sensor (holding data). That is, data “5” is the latest data in the first communication.

  Then, the data collection terminal 110 requests the slave station 200a to transmit new data in the order measured by the sensor, and the data “5” to “3” transmitted by the slave station 200a as data “5” as a response to the request. It is assumed that the signals are received in the order of “3”.

  Here, the slave station 200a may transmit data that overlaps the received data up to the previous communication and the received data of the current communication. For example, since the slave station 200a has not received the communication end signal from the data collection terminal 110 in the previous communication, the slave station 200a cannot determine the data that has been transmitted, and the received data up to the previous communication and the current data Data that overlaps with the received data of communication may be transmitted. FIG. 12 shows that the data “3” is acquired by the data collection terminal 110 as an example in the first communication.

  Subsequently, in the second communication, the storage unit 113 (see FIG. 3) is assumed to store data “1” to “5” that are received data up to the first time. The slave station 200a stores data “2” to “6” in the order measured by the sensor. That is, data “6” is the latest data in the second communication. Further, when the data “6”, which is the latest data, is stored in the storage unit of the slave station 200a, there is no space in the queue of the storage unit of the slave station 200a, so the data “1”, which is the oldest data, It is assumed that it has been deleted from the storage unit 200a.

  Then, the data collection terminal 110 requests the slave station 200a to transmit new data in the order measured by the sensor, and sets the data “6” to “4” transmitted by the slave station 200a as data “6” as a response to the request. It is assumed that the signals are received in the order of “4”.

  Here, the slave station 200a may transmit data that overlaps the received data up to the previous communication and the received data of the current communication. FIG. 12 shows that the data “4” and “5” are acquired by the data collection terminal 110 as an example in the second communication.

  Subsequently, in the third communication, the storage unit 113 (see FIG. 3) is assumed to store data “1” to “6” that are received data up to the second time. The slave station 200a stores data “3” to “7” in the order measured by the sensor. That is, the data “7” is the latest data in the third communication. Further, when the data “7”, which is the latest data, is stored in the storage unit of the slave station 200a, there is no space in the queue of the storage unit of the slave station 200a, so the data “2”, which is the oldest data, It is assumed that it has been deleted from the storage unit 200a.

  Then, it is assumed that the data collection terminal 110 requests the slave station 200a to transmit new data in the order measured by the sensor, and receives data “7” transmitted by the slave station 200a as a response to the request. FIG. 12 shows that continuous data “1” to “7” are acquired by the data collection terminal 110 as an example in the third communication.

  As described above, the data collection terminal 110 requests the slave station 200 to transmit new data in the order measured by the sensor, and receives the new data transmitted by the slave station 200 as a response to the request.

  Thereby, the data collection terminal 110 and the data management system 700 can collect data from the slave station 200 in order from the latest data.

[Fifth Embodiment]
A fifth embodiment of the present invention will be described in detail with reference to the drawings. In the fifth embodiment, the communication unit 112 of the data collection terminal 110 requests the slave station 200 to transmit continuous data in the order measured by the sensor, and transmits the continuous data transmitted by the slave station 200 as a response to the request. The receiving point is different from the first to fourth embodiments. Only differences from the first to fourth embodiments will be described below.

  FIG. 13 is a sequence diagram showing the communication operation between the data collection terminal 110 and the slave station 200 when the data collection terminal 110 receives continuous data in the order measured by the sensors. Here, the slave station 200a stores data “1” to “4” in the order measured by the sensor. That is, the data “4” is the latest data. Further, it is assumed that the data collection terminal 110 has received the data “1” by the previous communication. The slave station 200a may store data in a storage unit (not shown) having a queue structure.

  The control unit 111 (see FIG. 3) of the data collection terminal 110 has the data collection terminal 110 at a predetermined position “position A”. The data request is transmitted from the communication unit 112. Here, the control unit 111 causes the communication unit 112 to transmit a data request in order to request the slave station 200a to transmit continuous data in the order measured by the sensor.

  In the present embodiment, the control unit 111 requests the slave station 200a to transmit the data “2” following the data “1” received up to the previous communication. Transmit (step Se1). Then, as a response to the request, the slave station 200a transmits ACK to the data collection terminal 110 (step Se2).

  Further, the slave station 200a transmits the requested data “2” among the data for each time measured by the sensor to the data collection terminal 110 as a response to the request (data transmission). Then, the communication unit 112 stores the received data “2” in the storage unit 113 for each time measured by the sensor (step Se3). Further, the control unit 111 (see FIG. 3) causes an ACK (response) to be transmitted from the communication unit 112 to the slave station 200a (step Se4).

  Assume that the moving body 100 moves to the position B together with the data collection terminal 110. The control unit 111 (see FIG. 3) of the data collection terminal 110 communicates with the slave station 200a associated with the “position B” because the data collection terminal 110 is at the predetermined position “position B”. The data request is transmitted from the unit 112.

  Here, the control unit 111 causes the communication unit 112 to request the slave station 200a to transmit continuous data in the order measured by the sensor. For example, the control unit 111 causes the slave unit 200a to request the communication unit 112 to transmit the data “3” following the data “2” received up to the previous communication (step Se5).

  Then, the slave station 200a transmits ACK to the data collection terminal 110 as a response to the request (step Se6). Further, the slave station 200a transmits the requested data “3” among the data for each time measured by the sensor to the data collection terminal 110 as a response to the request (data transmission). And the communication part 112 memorize | stores the received data "3" in the memory | storage part 113 for every time which the sensor measured (step Se7). Then, the control unit 111 (see FIG. 3) causes ACK (response) to be transmitted from the communication unit 112 to the slave station 200a (step Se8).

  In subsequent steps, the data collection terminal 110 may similarly repeat the operations shown in steps Se1 to 4 (steps Se5 to 8).

  Further, the slave station 200a may stop data transmission if it cannot receive ACK (response) from the data collection terminal 110 even if it transmits the data a predetermined number of times (steps Se11 to 13). ). In addition, even if the data collection terminal 110 transmits a data request a predetermined number of times and cannot receive an ACK (response) from the slave station 200, the data collection terminal 110 may stop transmitting the data request.

  FIG. 14 shows received data for each communication when the data collection terminal 110 receives continuous data in the order measured by the sensor. Here, the received data is data received by the data collection terminal 110. Note that it is assumed that the data collection terminal 110 and the slave station 200a have already performed communication before the “first communication” shown in FIG.

  In the first communication, it is assumed that the storage unit 113 (see FIG. 3) stores data “1” and “2” that are received data until the previous communication. The slave station 200a stores data “1” to “5” in the order measured by the sensor (holding data). That is, data “5” is the latest data in the first communication.

  Then, the data collection terminal 110 requests the slave station 200a to transmit continuous data in the order measured by the sensor, and the data “5” to “3” transmitted by the slave station 200a as data responses “5” as a response to the request. ”To“ 3 ”.

  Subsequently, in the second communication, the storage unit 113 (see FIG. 3) is assumed to store data “1” to “5” that are received data up to the first time. The slave station 200a stores data “2” to “6” in the order measured by the sensor. That is, data “6” is the latest data in the second communication. Further, when the data “6”, which is the latest data, is stored in the storage unit of the slave station 200a, there is no space in the queue of the storage unit of the slave station 200a, so the data “1”, which is the oldest data, It is assumed that it has been deleted from the storage unit 200a.

  Then, the data collection terminal 110 requests the slave station 200a to transmit continuous data in the order measured by the sensor. That is, the data collection terminal 110 requests the slave station 200a to transmit the data “6” following the data “1” to “5” received up to the previous communication. Then, it is assumed that the data collection terminal 110 receives the data “6” transmitted from the slave station 200a as a response to the request.

  Subsequently, in the third communication, the storage unit 113 (see FIG. 3) is assumed to store data “1” to “6” that are received data up to the second time. The slave station 200a stores data “5” to “9” in the order measured by the sensor. That is, data “9” is the latest data in the third communication. In addition, when storing the latest data “7” and subsequent data “5” and “6” in the storage unit of the slave station 200a, the queue of the storage unit of the slave station 200a is not empty. It is assumed that old data “2” and subsequent data “3” and “4” are deleted from the storage unit of the slave station 200a.

  Then, the data collection terminal 110 requests the slave station 200a to transmit continuous data in the order measured by the sensor. That is, the data collection terminal 110 requests the slave station 200a to transmit the data “7” and “8” following the data “1” to “6” received up to the previous communication. Then, it is assumed that the data collection terminal 110 receives the data “7” and “8” transmitted by the slave station 200a as a response to the request. 14 shows that continuous data “1” to “8” are acquired by the data collection terminal 110 as an example in the third communication. Note that the data “9” that is the latest data in the third communication may be received by the data collection terminal 110 in the next communication.

  As described above, the communication unit 112 of the data collection terminal 110 requests the slave station 200 to transmit continuous data in the order measured by the sensor, and receives the continuous data transmitted by the slave station 200 as a response to the request. To do.

  Thereby, the data collection terminal 110 and the data management system 700 can collect continuous data from the slave station 200 in the order measured by the sensors.

[Sixth Embodiment]
A sixth embodiment of the present invention will be described in detail with reference to the drawings. In the sixth embodiment, the point that the communication unit 112 of the data collection terminal 110 requests the slave station 200 to transmit data selected according to the moving speed of the data collection terminal 110 is the first to fifth implementations. Different from form. Only the differences from the first to fifth embodiments will be described below.

  The control unit 111 calculates the moving speed of the communication unit 112 based on the position of the communication unit 112 measured by the positioning unit 114. Then, the control unit 111 selects data to be transmitted to the slave station 200a according to the moving speed of the communication unit 112, and causes the slave unit 200a to request the communication unit 112 to transmit the selected data. Then, the communication unit 112 requests the slave station 200a to transmit the data selected by the control unit 111.

  Here, when the control unit 111 selects data from the continuous data in the order measured by the sensor and acquires the selected data from the slave station 200, the control unit 111 determines the interval of the order of the acquired data ( Hereinafter, the “acquired data interval”) may be changed according to the moving speed of the communication unit 112.

  FIG. 15 shows an example of the relationship between the speed of the moving body 100 and the acquisition data interval. For example, the control unit 111 may increase the acquisition data interval so as to be proportional to the moving speed of the communication unit 112. Note that the control unit 111 may round off the decimal point of the moving speed of the communication unit 112.

  As an example, the acquired data interval is a value obtained by rounding off the decimal part of “speed of communication unit 112 [km / h] / 20 [km / h])”. In this case, if the speed of the communication unit 112 is less than 30 [km / h], “acquired data interval = 1”, and therefore, data to be transmitted to the slave station 200 is data “1”, “2”. , “3”, “4”,...

  Further, if the speed of the communication unit 112 is 30 [km / h] or more and less than 50 [km / h], “acquired data interval = 2”, so the data transmitted to the slave station 200 is the data “ 1 ”,“ 3 ”,“ 5 ”,“ 7 ”,...

  Further, if the speed of the communication unit 112 is 50 [km / h] or more, “acquired data interval = 3”, and therefore, data to be transmitted to the slave station 200 is data “1”, “4”, “7”. ”,“ 10 ”,...

  FIG. 16 shows an example of “how to collect” data collected by the data collection terminal 110. The data management system 700 or the data collection terminal 110 interpolates unacquired data that has not been received among the data measured by the sensor of the slave station 200 based on the acquired data received from the slave station 200. Also good. For example, when “acquired data interval = 2”, the data collection terminal 110 acquires the acquired data “3 degrees Celsius” measured at time 0 and the acquired data “3 degrees Celsius” measured at time 2 ”, The unacquired data“ 3 degrees Celsius ”measured at 1 o'clock may be estimated and interpolated.

  FIG. 17 shows the relationship between the moving speed of the moving body 100 and the number of received data. Hereinafter, the distance from the communication start position to the communication end position is referred to as “communication distance”. The communication distance is assumed to be x [m]. Here, it is assumed that the moving body 100 has moved to the position A (communication start position) at the moving speed y [m / s]. In this case, the time z during which the slave station 200a and the data collection terminal 110 can communicate is “z [s] = x / y”.

  For example, when the communication unit 112 (see FIG. 3) of the data collection terminal 110 can receive (acquire) a data amount of 96 [bytes] per 0.1 [s], the mobile unit The amount of data d that can be received (acquired) by the communication unit 112 before 100 passes the position C (communication end position) is “d = z / 0.1 × 96 [bytes]”. .

  For example, when 4 [byte] capacity data is measured every hour, the data amount per day is 96 (= 4 × 24) [bytes]. If “x = 150 [m]” and “y = 8.3 [m / s]”, then “z = 18 [s]” and “d = 17280 [bytes]”. Here, 17280 [bytes] corresponds to a data amount of about 180 days (about six months). If the data amount is about half a year, the data collection terminal 110 may collect data every other day of the year.

  As described above, the communication unit 112 of the data collection terminal 110 requests the slave station 200 to transmit data selected according to the moving speed of the data collection terminal 110. Thereby, the data management system 700 or the data collection terminal 110 can efficiently collect data from the slave station 200 of the sensor network.

  For example, the data management system 700 or the data collection terminal 110 changes the acquisition data interval according to the time during which the slave station 200 and the data collection terminal 110 can communicate, and receives data from the slave station 200 of the sensor network. It can be collected efficiently.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

  For example, the slave station 200 may periodically repeat a sleep mode in which power consumption is reduced and activation (for example, a cycle of 10 seconds). Further, the slave station 200 may be activated from the sleep mode, triggered by reception of a wake-up signal for activating the slave station 200.

  Further, for example, the data management system 700 calculates the capacity of the data stored in the slave station 200 based on the sensor measurement period and the like before the data collection terminal 110 collects the data. May be.

  For example, the data collection terminal 110 may collect data irregularly.

  For example, a fixed line may be used for a part of communication between nodes.

  A program for realizing the procedure described with reference to FIGS. 5, 6, 9, 10, 11, and 13 is recorded on a computer-readable recording medium, and the program is read into a computer system and executed. You may do it. Here, the “computer system” includes an OS and hardware such as peripheral devices. The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Further, the “computer-readable recording medium” refers to a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network such as the Internet or a communication line such as a telephone line. In addition, those holding programs for a certain period of time are also included. The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line. The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, what is called a difference file (difference program) may be sufficient.

DESCRIPTION OF SYMBOLS 100 (100a-100b) ... Mobile body, 110 ... Data collection terminal, 111 ... Control part, 112 ... Communication part, 113 ... Memory | storage part, 114 ... Positioning part, 120 ... Drive part, 200a-200e ... Slave station, 300a- 300b ... relay station 400 ... master station 500 ... communication device slave station 600 ... communication device master station 700 ... data management system 710 ... communication unit 720 ... determination unit 730 ... instruction unit 740 ... storage unit

Claims (7)

In a sensor network comprising nodes that transmit data measured by sensors,
A positioning unit that measures the position of the terminal;
Based on the position measured by the positioning unit, it is determined whether or not the own terminal is at a predetermined position, and when the own terminal is at the predetermined position, the node transmits the data. And a communication unit that receives the data transmitted by the node as a response to the request;
A data collection terminal comprising:   2. The communication unit requests the node to transmit the data through a plurality of channels, and receives the data transmitted by the node as a response to the request through the plurality of channels. The data collection terminal described in 1.   The communication unit requests the node to transmit the new data in the order measured by the sensor, and receives the new data transmitted by the node as a response to the request. Item 3. The data collection terminal according to Item 2.   The communication unit requests the node to transmit the continuous data in the order measured by the sensor, and receives the continuous data transmitted by the node as a response to the request. The data collection terminal according to claim 1.   The communication unit requests the node to transmit the data selected according to the moving speed of the terminal from the data measured by the sensor, and the node transmitted as a response to the request 5. The data collection terminal according to claim 1, wherein the selected data is received.   The said communication part requests | requires the said node to transmit the said data which the said communication part has not received among the said data which the said sensor measured, The Claim 1 characterized by the above-mentioned. The data collection terminal according to one. A data collection terminal according to any one of claims 1 to 6,
A mobile body equipped with the data collection terminal and moving,
A data collection system comprising:

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