JP2017228933A - Sensor network system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sensor network system capable of deriving a communication path by measuring a RSSI value between a transmitter and a relay or between relays and receiving reception data on which timer counting is started at the time of transmission start by the transmitter and a timer count value is updated on the way.SOLUTION: A transmitter 110 starts counting a timer from a start of measurement. After completion of the measurement, the transmitter embeds the transmitter's ID and a timer value at timing at which transmission from the transmitter to a reception destination starts into a number zero area and number two area in a frame before transmitting the frame. A relay 4, when receiving the frame, reads a progress counter value in the received frame; takes over the value and embeds a received timer value into an own reception counter in a number eleven area in the frame; and sets the counter value taken over into the number two area in the frame before starting counting of update by a timer in the relay. The relay 4 also measures RSSI at the time of receiving the frame and embeds a value thereof into a number seven area in the frame before transmitting the frame.SELECTED DRAWING: Figure 8

Description

  According to the present invention, a transmitter measures power consumed by being attached to a distribution board such as a factory, a building, or a store, and a receiver in the network receives measurement data transmitted from the transmitter. The present invention relates to a sensor network system that aggregates measurement data transmitted from a host system device.

  In a conventional mesh sensor network, each wireless device has a table of the number of hops used to select the communication path. When selecting a communication path from the transmitter to the receiver, the number of hops is checked. However, a communication path with a small number of hops was selected.

In that case, only the receiver at the final stage of the communication path manages the received signal strength indicator (RSSI) of the received radio wave.
However, when a relay is used, the receiver does not grasp the RSSI of the radio wave between the transmitter and the repeater or between the repeater and the repeater. Alternatively, the RSSI value could not be confirmed unless directly connected to the receiver or the repeater for measurement.

By the way, in the field of wireless communication, since communication may be interrupted due to a decrease in radio wave reception intensity or interference, it is very important to examine the appropriateness of the installation position of the wireless device.
In particular, wireless communication is greatly affected by the environmental conditions of communication, the signal strength at the receiving point is not stable due to the influence of surrounding equipment and people movement, and fluctuations of 20 dB per day may occur.

  From the above considerations, when installing a wireless device in a sensor network system, the wireless communication network is determined by determining the installation position of the wireless device by measuring the signal strength of the reception point and confirming the communication path. It is important to build.

  However, with the conventional network technology, only the RSSI value of the radio wave received by the receiver can be measured, and when the relay is used, the RSSI of the radio wave between the transmitter and the repeater or between the repeater and the repeater is measured. Since it was not possible, the distribution of the RSSI value of the radio waves in the entire wireless communication network was not known, and the validity of the installation position could not be determined.

  Or, since the RSSI value cannot be confirmed unless it is directly connected to each wireless device, it is extremely inefficient because an engineer is dispatched to the site and the RSSI value must actually be individually acquired from the wireless device.

  In selecting a communication path, the wireless device has a hop count table and can confirm the number of hops from the transmitter to the receiver. However, the actual communication path cannot be determined by itself.

  Japanese Patent Application Laid-Open Publication No. 2004-228688 periodically transmits a field strength measurement signal for field strength measurement from a terminal device wirelessly, and each terminal device that has received the signal manages the reception level of the signal as field strength information. The management apparatus creates and manages a plurality of communication paths including relay paths between the terminal apparatuses based on the electric field strength information, and the terminal apparatus performs desired communication from the plurality of communication paths created and managed by the management apparatus. A communication path determination technique considering communication errors in a wireless communication network that selects a communication path that satisfies a required condition is disclosed.

  Further, Patent Document 2 below calculates a plurality of radio wave paths that reach from one transmitting wireless node to another receiving wireless node from the shape and position information of a structure that generates a physical phenomenon that affects the radio wave path. The received power is calculated for each radio wave path, and further, a structure that affects reflection, transmission, or diffraction is obtained in each of the plurality of radio wave paths, and the received power is calculated using the existence probability of the structure. And assessing the availability of each radio wave path based on the adjusted received power and constructing a wireless communication network using a relay path with a better radio wave propagation state .

JP-A-11-168526 Japanese Patent No. 5076156

  The above-mentioned Patent Document 1 wirelessly transmits a field strength measurement signal for periodically measuring a field strength from a terminal device, and each terminal device that has received the signal manages the reception level of the signal as field strength information. The management apparatus creates and manages a plurality of communication paths including relay paths between the terminal apparatuses based on the electric field strength information, and the terminal apparatus creates a plurality of communication paths created and managed by the management apparatus. Therefore, there is a problem that the control for determining the communication path in the wireless communication network is complicated.

  Further, Patent Document 2 calculates a plurality of radio wave paths that reach from one transmitting wireless node to another receiving wireless node from the shape and position information of a structure that generates a physical phenomenon that affects the radio wave path. , Calculate the received power for each radio path, find the structure that affects diffraction, adjust the received power using the existence probability of the structure, and evaluate the availability of each radio path However, although a wireless communication network is constructed using a relay route having a good radio wave propagation state, there is a problem that the process leading to the network construction is complicated.

  As described above, in the conventional communication network technology, only the RSSI value of the radio wave received by the receiver can be measured. When the signal is passed through the repeater, the radio wave between the transmitter and the repeater or between the repeater and the repeater. Since the RSSI value of the wireless device could not be measured, the distribution of the RSSI value of the radio wave in the entire wireless communication system with the mesh configuration was not known, and there was a problem that the validity of the installation position of the wireless device could not be determined.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a timer count value in the middle of the measurement of the RSSI value between the transmitter and the repeater or between the repeater and the repeater and the start of counting the timer from the start of transmission of the transmitter in the mesh sensor network system. It is an object of the present invention to provide a sensor network system capable of determining a communication path by receiving received data for performing update.

In order to solve the above-mentioned problem, the invention according to claim 1 of the present invention is a sensor network system having a mesh configuration, wherein the sensor network system includes:
A transmitter having a measurement function and a wireless communication function and not having a relay function;
A repeater that does not have a measurement function and has a mesh relay function;
A receiver for transmitting and receiving radio waves between the transmitter and the repeater;
A host system connected to the receiver and having a function of observing at least each communication status of the sensor network; and
The transmitter is
Means for transmitting a beacon prior to the start of communication and selecting either a repeater or a receiver from the response;
Means for counting up a timer from the moment measurement is started and embedding a time required for transmission of measurement data as a counter value in a predetermined area of the data frame;
Means for embedding the ID of the local station in a predetermined area of the data frame,
The repeater is
Means for measuring an RSSI value at the time of reception of a data frame transmitted by the transmitter and embedding the measured RSSI value in a predetermined area of the data frame allocated to the own station;
The data frame transmitted by the transmitter is received, the counter value embedded in the data frame is read, the timer built in the local station is counted up based on the value, and it is necessary for the relay transmission of the measurement data. Means for embedding as a counter value in a predetermined area of the data frame,
The receiver
Means for measuring an RSSI value at the time of receiving a data frame transmitted by the immediately preceding relay or transmitter, and embedding the measured RSSI value in an area of the data frame allocated to the own station;
Means for receiving the data frame including the RSSI value, the counter value, and the repeater ID embedded in each of the repeaters involved until reaching the own station;
Means for transmitting the RSSI value measured by the local station, and a data frame including the RSSI value, the counter value, and the relay ID received by the local station to a higher-level device;
The host system apparatus displays an RSSI value for each communication path on the floor map of the screen based on the data frame transmitted from the receiver, and the contents are viewed and analyzed by an operator to analyze the receiver and the receiver. The arrangement position of the repeater is evaluated.

The invention according to claim 2 of the present invention is a transmitter in a sensor network system having a mesh structure, and the transmitter has a measurement function and a wireless communication function but does not have a relay function.
A means for broadcasting a beacon before the start of communication, and selecting a partner having the strongest RSSI value from among the responses as a receiver of measurement data;
Means for counting up a timer from the moment when measurement of consumed power is started and embedding a time required for transmission of measurement data as a counter value in a predetermined area of the formatted data frame;
Means for embedding the ID of the local station in a predetermined area of the data frame,
The transmitter measures power consumption and stores it in its own memory, reads the stored power data from the memory, embeds it in a predetermined area of the data frame, and transmits the data frame to a receiver at a predetermined cycle It is characterized by.

The invention according to claim 3 of the present invention is a repeater in a sensor network system having a mesh configuration, and the repeater has a mesh relay function without having a measurement function,
Means for measuring an RSSI value at the time of reception of a data frame transmitted by the transmitter and embedding the measured RSSI value in a predetermined area of the data frame allocated to the own station;
The data frame transmitted by the transmitter is received, the counter value embedded in the data frame is read, the timer built in the local station is counted up based on the value, and it is necessary for the relay transmission of the measurement data. Means for embedding as a counter value in a predetermined area of the data frame,
The repeater relays and transmits the data frame to which the RSSI value embedded in the predetermined area of the data frame assigned to the own station, the updated timer counter value, and the repeater ID are added to the forward or lateral repeater. It is characterized by.

The invention according to claim 4 of the present invention is a receiver in a sensor network system having a mesh configuration, wherein the receiver transmits and receives radio waves between the transmitter and the repeater,
Means for measuring an RSSI value at the time of receiving a data frame transmitted by the immediately preceding relay or transmitter, and embedding the measured RSSI value in an area of the data frame allocated to the own station;
Means for receiving the data frame including the RSSI value, the counter value, and the repeater ID embedded in each of the repeaters involved until reaching the own station;
Means for transmitting the RSSI value measured by the local station, and a data frame including the RSSI value, the counter value, and the relay ID received by the local station to a higher-level device;
The receiver sends the received data frame to a host system connected to the local station via a LAN.

The invention according to claim 5 of the present invention is a host system apparatus connected to a receiver in a mesh sensor network system via a network, and the host system apparatus is connected to the receiver via a LAN,
The host system device is
Means for displaying an RSSI value for each communication path on the floor map of the screen based on the data frame transmitted from the receiver;
Means for displaying an RSSI trend in a specific transmitter on the screen based on the data frame transmitted from the receiver,
The content displayed on the screen is viewed and analyzed by an operator, and the arrangement positions of the receiver and the repeater are evaluated.

In the invention according to claim 6 of the present invention, the sensor network system includes a transmitter having a measurement function and a wireless communication function and not having a relay function, and a relay having no meshing function and having no measurement function. A receiver that transmits and receives radio waves between the transmitter and the repeater, and a host system that is connected to the receiver and has a function of observing at least each communication status of the sensor network. A method for properly arranging wireless devices in a sensor network system having a mesh configuration,
The process of temporarily placing a wireless device including a transmitter, a repeater, and a receiver before determining the proper placement of the wireless device;
The process of constructing the network in the temporarily placed state and starting counting the timer of the transmitter when the measurement data is transmitted using the constructed network,
A process of measuring the updated value of the timer and the RSSI value at the reception time at the reception time in the relay connection until the measurement data reaches the receiver;
Embedding the updated timer value and the RSSI value in an area corresponding to the relay unit involved in the relay in a data format including measurement data at the reception time in the relay connection;
Sending a value embedded in each area in the data format received by the receiver to a higher-level device; and
The RSSI value in the network is displayed on the screen by the host system on the basis of the value embedded in each area in the transmitted data format, the contents are viewed and analyzed by the operator, and the wireless device on the network A process of determining an appropriate arrangement of the.

  According to the present invention, a transmitter, a repeater, and a receiver are temporarily placed before determining the arrangement of the wireless device on the network, measurement is performed in the temporarily placed state, and data is transmitted to the receiver via the sensor network. By monitoring the RSSI value and the timer value included in the data format at the time, it is possible to determine the appropriate arrangement of the wireless device on the network by obtaining an indication of the appropriate arrangement of the wireless device in the network Become.

  As a result, the installation distance between wireless devices can be reduced, the installation distance between wireless devices can be increased, or the arrangement of repeaters that are not functioning at all can be grasped, and the appropriate arrangement of the wireless devices can be determined. This makes it possible to construct a better sensor network.

  Furthermore, even if communication failure may occur later due to changes in the wireless environment after installation, by applying the present invention, the operator can cause the cause of communication abnormality without dispatching engineers to the site. By grasping on the screen, it is possible to improve so that communication abnormality does not occur.

It is a figure which shows the structure outline | summary of the sensor network system to which this invention is applied. It is a figure which shows the example of arrangement | positioning of the radio | wireless apparatus before determining the hop number used as the premise of this invention. FIG. 3 is a functional block diagram illustrating a configuration of a receiver illustrated in FIG. 2. It is a functional block diagram which shows the structure of the relay machine shown by FIG. FIG. 3 is a functional block diagram illustrating a configuration of a transmitter illustrated in FIG. 2. It is a figure which shows an example of the wireless transmission data format used with the sensor network system which concerns on embodiment of this invention. It is a figure which shows the data transmission sequence which concerns on embodiment of this invention, Comprising: It is a sequence chart explaining the end of the routing of this invention. It is a sequence diagram which shows a mode that the communication path | route from a transmitter is decided based on transition of the reception counter value in the data format received by the receiver which concerns on embodiment of this invention. It is the figure which displayed on the screen the fixed communication path | route shown in FIG. It is a figure which shows the example of arrangement | positioning in the building of the radio | wireless apparatus which concerns on embodiment of this invention. It is a figure which shows the mode of the wireless transmission in the example of arrangement | positioning in the building of the radio | wireless apparatus shown in FIG. FIG. 12 is a diagram in which the host system apparatus receives the status of the wireless transmission shown in FIG. 11 via the receiver of the present invention and displays the received data on the floor map of the screen. It is a figure which shows an example of the RSSI trend at the time of the reception of the data transmitted from the transmitter installed in the building 5 floor displayed on the screen of the high-order apparatus. It is a figure which shows the mode of the radio transmission after changing the example of arrangement | positioning of the radio | wireless apparatus shown in FIG. FIG. 15 is a diagram in which the host system apparatus receives the status of the wireless transmission shown in FIG. 14 via the receiver of the present invention and displays the received data on the floor map of the screen.

Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 is a diagram showing a schematic configuration of a sensor network system to which the present invention is applied. The sensor network 1 of FIG. 1 is constructed by arranging a single receiver 120, a plurality of relays 130 to 160, and a single transmitter 110 as an example.

The receiver 120 can receive the measurement data transmitted from the transmitter 110 via the plurality of relays 130 to 160, and has a function of sending the received result to the host system device.
The repeaters 130 to 160 do not have a measurement function and have a mesh relay function, and the transmitter 110 does not have a relay function and has a power measurement function and a wireless communication function. Can transmit and receive wireless radio waves between them and transmit measurement data acquired by the local station to a repeater or receiver.

  Although not shown in FIG. 1, the host system device includes a PC (Personal Computer), is connected to the receiver 120 via a network, and is based on a data frame received from the receiver 120, an output device (display). Means).

  The transmitter 110 shown in FIG. 1 includes a CT (Current Transformer) 17 connected to the R phase and the T phase of the three-phase alternating currents R, S, and T, and the three-phase alternating currents R, S, and T. Connected to VT (Voltage Transformer) 18 connected to each phase, and calculates power after converting current / voltage transformed / transformed by CT and VT to current / voltage for meter. Then, the measurement data is recorded in the memory 52 in the transmitter shown in FIG.

  In the above, the CT (current transformer) 17 is a kind of instrument transformer for converting the current of the large current circuit into the current required for the instrument and relay, and the VT (instrument transformer) 18 is a high voltage. It is used as a kind of instrument transformer that converts the voltage of the circuit into an easy-to-handle voltage (usually 110V) required for the instrument and relay.

  The transmitter 110 first transmits an RREQ (RNO (radio device number) request) signal in the network in accordance with a data transmission sequence (details will be described later) introduced into the sensor network of the present invention before starting communication. Broadcast to other wireless devices.

  RNO (Radio Number: Radio number) indicating that the wireless device (eg, repeater) that received the RREQ (RNO request: radio number request) signal is ready to relay measurement data sent from the transmitter ) Respond to the transmitter 110 with a signal.

  The transmitter 110 selects a partner having the strongest RSSI (Received Signal Strength Indicator) of the response RNO signal as a reception destination of the measurement data. In the example of FIG. 1, it is shown that the relay device 4 (F4) 160 is selected as the reception destination.

  The determination of the destination of relay data transmission from the relay device 4 (F4) 160 and the relay transmission are the same as described above, and the relay device 4 (F4) 160 to the relay device 2 (F2) 140, and further the relay device 2 (F2). 140 is determined as the relay device 1 (F1) 130, and finally, the relay transmission of the measurement data is performed from the relay device 1 (F1) 130 to the receiver 120.

Details of the above-described receiving destination determination routing (communication path search) processing will be described later. Note that the repeater 3 (F3) 150 is not selected in the above routing process.
The repeater described above is installed between the transmitter 110 and the receiver 120 and relays when the distance from the transmitter 110 to the receiver 120 is longer than the reach of the radio signal. This is for completing communication and is adopted in various wireless communication systems.

  FIG. 2 is a diagram illustrating an arrangement example of wireless devices before determining the number of hops as a premise of the present invention. As an example, the wireless device shown in FIG. 2 tries to construct a sensor network system having a mesh structure in which a single receiver 11, a plurality of relays 12 to 16, and a plurality of transmitters 21 to 23 are arranged. It shall be.

  The receiver 11 has a function of collecting measurement data transmitted from the transmitters 21 to 23 and the relay devices 12 to 16 and sending the collected measurement data to the host system device. The repeaters 12 to 16 have only a relay function without having a measurement function, and the transmitters 21 to 23 have a power measurement function and a wireless communication function without having a relay function.

Each wireless device shown in FIG. 2 does not have routing information on which wireless device other than its own station can communicate with, and is in the previous stage when starting communication. That means
In the example of FIG. 2, the receiver 11 in the arranged wireless device takes the initiative to start routing. That is, the receiver 11 transmits a beacon every 3 seconds and starts routing in order to determine the number of hops of the repeaters 12 to 16 and the transmitters 21 to 23.

Since a beacon is transmitted every 3 seconds, even if the communication environment of the wireless device changes, the number of hops can be corrected / updated after 3 seconds.
2 receives the beacon transmitted from the receiver 11, increases the number of hops stored in its own memory (described later) by 1, and further transmits the beacon. Send. The number of hops of the receiver that first transmits the beacon is set to zero.

  Then, the repeaters 12 to 16 responding to the beacon increase the number of hops stored in their own memory (to be described later) by 1 to the number of hops of their own station, and also transmit the beacon in the same manner as the receiver. To relay the beacons emitted by the receiver 11 one after another.

    The receiver 11, the repeaters 12 to 16 and the transmitters 21 to 23 hold the number of hops (the number of relay stages to the receiver) in their own memory (described later), The number of hops of the wireless device that has transmitted the beacon is embedded in the data.

The repeaters 12 to 16 or the transmitters 21 to 23 that have received the beacon increase the number of hops in the beacon by 1, and store it in the local station memory (described later) as the hop number of the local station.
Assuming that the relay device that has received the beacon from the receiver 11 and this is the relay device A, the relay device A increases the number of hops by 1, and then transmits a beacon in the same manner as the receiver 11.

  Assuming that the relay device that could not receive the beacon from the receiver 11 and this relay device B, when the relay device B receives a beacon transmitted from the relay device A with a hop number of 1, the local station memory (described later) ), The number of hops of the relay station B that has received the beacon from the relay station A becomes two.

  Hereinafter, similarly, assuming that the relay device that has received the beacon transmitted from the relay device B with the hop number 2 and this is the relay device C, the relay device C transmits the beacon transmitted from the relay device B with the hop number 2. When received, the number of hops of the relay C that has received the beacon from the relay B becomes 3 by further increasing the number of hops stored in its own memory (described later) by one.

  In the following, the above procedure is repeated in the same manner, and if the relay device that can receive the beacon transmitted from the relay device C with the hop number 3 is assumed to be the relay device D, the hop number of the relay device D is 4. .

  In this process, a beacon transmitted from a repeater having the same number of hops as the local station or larger than the local station is ignored. As a result, the number of hops in each wireless device is determined.

Such a hop number determination and routing technique is disclosed in, for example, Japanese Patent Application Laid-Open No. 2014-150478, and is referred to as necessary.
In the arrangement example of the wireless devices in FIG. 2, after the number of hops of each wireless device is determined, transmission of measurement data measured by the transmitters 21 to 23 toward the receiver 11 is started.

The transmitters 21 to 23 do not have a relay function, but have a power measurement function and a wireless communication function.
That is, the transmitters 21 to 23 shown in FIG. 2 are connected to the distribution board and consume the power every other minute like the transmitter 110 of FIG. 1 via the CT and VT shown in FIG. Performs measurement and transmits measured data.

  The transmitter 21 in FIG. 2 corresponds to the transmitter 110 shown in FIG. 1, but when the other transmitters 22 and 23 shown in FIG. 2 transmit measurement data, the transmitter 21 is the same as the transmitter 21. Since it corresponds, it abbreviate | omits description.

  When transmitting the measured data, according to the sequence described later, relay transmission (data transfer) is performed to the repeaters 12 to 16 having the smaller hop count, and the repeaters 12 to 16 having the smaller hop count transmit this to the receiver 11. Repeat relay transmission (data transfer) until it arrives.

  As described above, the relay station with a small number of hops relays (data transfers) the measurement data transmitted based on the number of hops to the relay station with a smaller number of hops. Thus, finally, the measurement data measured by the transmitters 21 to 23 is collected and received by the receiver 11.

Here, the operation will be briefly described with reference to functional block diagrams showing the configurations of the transmitter, repeater, and receiver.
FIG. 3 is a functional block diagram showing the configuration of the receiver shown in FIG. 2, which is also used in the embodiment of the present invention.

In FIG. 3, the receiver 11 includes a receiver control unit 30, an intermittent operation control unit 31, a data transmission / reception control unit 34, a communication unit 35, a radio unit 37, and an antenna 38.
As described above, the receiver is responsible for collecting the measurement data transmitted from the transmitter or relay device and transmitting it to the host system device 36. That is,
The receiver receives measurement data transmitted from the transmitter or the relay device via the antenna 38. When data is received, a signal indicating that the data has been received is notified to the intermittent operation control unit 31 via the data transmission / reception control unit 34, and the received data is written to a predetermined area of the memory 32.

Further, the time counter value in the transmission data format is taken over and the timer is updated and written in a predetermined area of the memory 32.
The written reception data and timer counter value are read by the memory control unit 33 and sent to the host system device 36 via the communication unit 35.

  Further, based on the control operation of the intermittent operation control unit 31, the receiver control unit 30, the data transmission / reception control unit 34, the communication unit 35, and the radio unit 37 perform operation control intermittently, and a battery power source (not shown) Holding power.

  The memory 32 is controlled to be read / written by the memory control unit 33, and sends the data written in the area allocated for each wireless device to the host system device 36 in response to data reception. Note that the hop count determination method is disclosed in the above-described known examples, and thus the description thereof is omitted here.

FIG. 4 is a functional block diagram showing the configuration of the repeater shown in FIG. 2, which is also used in the embodiment of the present invention.
In FIG. 4, the repeaters 12 to 16 include a repeater control unit 40, an intermittent operation / time counter control unit 41, a time counter unit 44, a data transmission / reception control unit 45, a radio unit 46, and an antenna 47.

As described above, the relay machine has only the relay function of the measurement data transmitted from the transmitter without having the measurement function.
The measurement data transmitted from the transmitter or another relay is received via the antenna 47, and the received data is once written in a predetermined area of the memory. Further, the intermittent operation / time counter control unit 41 is notified of the data reception via the data transmission / reception control unit 45.

  The intermittent operation / time counter control unit 41 intermittently controls the operation of the repeater control unit 40, the data transmission / reception control unit 45, and the wireless unit 46 to hold power of a battery power source (not shown), and the repeater control unit 40 time counter units 44 are controlled to take over the time counter value in the transmission data format and update the timer to write to a predetermined area of the memory 42.

  The received data and the updated counter value written in the memory 42 are read based on the intermittent operation / time counter control unit 41, the control of the time counter unit 44, and the reading control by the memory control unit 43, and the data transmission / reception control unit 45. Then, relay transmission (data transfer) is performed via the radio unit 46 and the antenna 47 to the above-described radio apparatus such as a repeater with a small number of hops.

  The memory 42 is read / write controlled in accordance with instructions from the memory control unit 43 and the time counter unit 44, and reads the measurement data and the updated time count value written in the area of each wireless device corresponding to the relay transmission of data. Then, the data is transferred to a predetermined area of a wireless transmission data format (described later) and transferred to a wireless device such as a repeater with a small number of hops.

Note that the hop count determination method is disclosed in the above-described known examples, and thus the description thereof is omitted here.
FIG. 5 is a diagram showing functional blocks showing the configuration of the transmitter shown in FIG. 2, and is also used in the embodiment of the present invention.

  In FIG. 5, transmitters 21 to 23 include a transmitter control unit 50, an intermittent operation / time counter control unit 51, a time counter unit 54, a data transmission / reception control unit 55, a measurement unit 56, a radio unit 57, and an antenna 58. Become.

As described above, the transmitter does not have a relay function and is provided with a power measurement function and a wireless communication function.
The transmitters 21 to 23 are attached to the distribution board, and the measurement unit 56 calculates the power consumed based on the value of a meter (not shown), and measures in a predetermined area assigned to the own transmitter of the memory 52. Write data.

  The transmitters 21 to 23 read the measurement data written in the memory 52 based on the intermittent operation / time counter control unit 51, the control of the time counter unit 54, and the reading control by the memory control unit 53, and the data transmission / reception control unit 55, Relay transmission (data transfer) is performed via the wireless unit 57 and the antenna 58 to the above-described wireless device such as a relay device with a small number of hops.

Specifically, the recorded measurement data is transmitted every minute to a repeater or receiver with a small number of hops.
The memory 52 is read / write controlled according to instructions from the memory control unit 53 and the time counter unit 54, and reads the measurement data written in the area assigned to each transmitter and the updated time count value and wirelessly transmits them. The data is transferred to a predetermined area of a data format (described later), and the data is transferred to a wireless device such as a repeater with a small number of hops.

Note that the hop count determination method is disclosed in the above-described known examples, and thus the description thereof is omitted here.
FIG. 6 is a diagram illustrating an example of a wireless transmission data format used in the sensor network system according to the embodiment of the present invention.

In the wireless transmission data format shown in FIG. 6, the storage area is partitioned for each data type.
That is, the zero number area of the wireless transmission data format is an area in which a transmitter ID for identifying a transmitter number is embedded. This transmitter ID does not change even if a relay unit gets involved, and is sent to the receiver that is the destination of transmission data.

The first area is an area in which the data measured by the measuring unit 56 in the transmitter is embedded in the frame.
The second area counts up the own station timer from the moment the transmitter starts measurement and embeds the time required for data transmission in the area as the value of the elapsed counter and transmits it together with the measurement data.

Until reaching the receiver, the repeater involved in the relay takes over the value of the progress counter and updates the timer value with its own timer.
The third to seventh areas measure RSSI (Received Signal Strength) when receiving the transmitted or relayed measurement data, and embed the RSSI values in the areas assigned to them.

  The 8th to 11th areas take over the value embedded in the elapsed counter area when data is received, update the time counter of each relay machine, and further embed the counter value in the elapsed counter.

  In other words, the value embedded in the progress counter value in the second area is taken over, the counter value updated by performing the update count in the relay device is embedded in the progress counter, and the updated counter value is set in any of the eighth to eleventh areas. The value is embedded in the reception counter area assigned to the relay ID, that is, assigned to the relay ID.

FIG. 7 is a sequence chart illustrating a data transmission sequence according to the embodiment of the present invention and explaining one end of the routing of the present invention.
In FIG. 7, the vertical line on the left shows the operation of the transmitter or relay that is the transmission side of measurement data, and the vertical line on the right shows the operation of the receiver or relay that is the reception side of measurement data. The operation is shown. The numbers indicate the order of transmission / reception of signals and the like (sequence).

The data transmission sequence and one end of the routing according to the embodiment of the present invention will be described with reference to FIG.
Data transmission and routing are started by a wireless device (eg, transmitter 110 shown in FIG. 1) on the measurement data transmission side.

  (1) In order to start transmission, the transmitter 110 first multicasts an RREQ (RNO request) signal from the measurement data transmission side to the measurement data reception side. That is, the measurement data transmission side requests the measurement data reception side for a response of the RNO (radio device number and hop number) on the reception side.

(2) The receiving side (eg, repeater 4 (F4) 160 shown in FIG. 1) that has received the RREQ signal returns its own RNO (radio number and hop number) as a response to the data transmitting side. To do.
(3) Next, according to the routing procedure, can the data transmission side select a reception partner that is forward-forwarding (direction in which the number of hops is reduced) and transmit the measurement data from the data transmission side to the data reception side? A signal for confirming, that is, a data transmission request is made.

  (4) On the other hand, the receiving side that has received the data transmission request returns a response having the meaning of data transmission permission, that is, a transmission request acknowledgment in order to indicate that the measurement data is ready to be received.

  (5) Next, the transmission side that has received the transmission request acknowledgment transmits the transmission data (packet data) within a predetermined timing. At that time, a SUM value (error detection code) is added.

  (6) The receiving side that has received the single transmission data (packet data) confirms the SUM value added to the single transmission data, and indicates that the measurement data has been successfully received if no error is detected. The data acknowledgment is returned to the transmission side.

By receiving the data acknowledgment, the transmission side determines that the transmission (transfer) of the measurement data has been completed. This completes a series of data transmission sequences.
The data transmission sequence shown above is a normal case. In the following cases, the sequence can be changed / omitted. That is,
In the above (2), when the RNO from the receiver can be directly received, the measurement data is immediately transmitted to the receiver.

  In (3) above, if multiple RNOs are sent from the receiving side within the RNO waiting period, all RNOs with hops on the responding side included in the RNO are ignored. Transfer data only to the first forward-facing RNO (less hops than you).

  Furthermore, in the above (3), when the forward RNO is not received when half of the RNO waiting period has elapsed, the data transfer to the RNO having the same number of hops as that of itself is permitted, that is, the horizontal transfer is permitted. To do.

FIG. 8 is a sequence diagram showing how a communication path from a transmitter is determined based on a reception counter value in a data format received by a receiver according to an embodiment of the present invention.
As shown in FIG. 8, the transmitter 110 starts incrementing the timer in the time counter unit 54 from the moment measurement is started.

  After the measurement by the measuring unit 56 of the transmitter 110 is completed, the local station ID and the timer value of the timing for starting transmission from the local station to the receiving party are set to the zeroth region and the second region in the wireless transmission data frame (see FIG. 6). Send it embedded in the area. At that time, the measurement data is embedded in the first area.

  When the repeater 4 (F4) 160 receives this, it reads the timer value of the elapsed counter in the received wireless transmission data frame, takes over the timer value, and takes over the 11th area in the wireless transmission data frame (see FIG. 6). In addition, the received timer value is embedded in the reception counter (F4), and the counter value taken over by the local station timer is set to start incrementing the update by the local station timer in the relay station.

  Further, the repeater 4 (F4) 160 measures the RSSI (Received Signal Strength) value when the above-mentioned wireless transmission data frame is received, and the wireless transmission data frame (FIG. 6) assigned to the own station. It is embedded in the 7th area in the reference) and transmitted.

  Next, the relay device 2 (F2) 140 receives the wireless transmission data frame including the measurement data relayed by the relay device 4 (F4) 160, reads the timer value of the elapsed counter in the data frame, and transmits the wireless transmission data frame ( The received timer value is embedded in the 9th area in FIG. 6), and the counter value taken over by the own station timer is set, and the update increment by the own station timer in the relay station is started.

  Further, the repeater 2 (F2) 140 measures the RSSI (received signal strength) when the wireless transmission data frame is received, and assigns the value to the wireless transmission data frame (see FIG. 6). It is embedded in the fifth area in) and transmitted.

Further, when the repeater 1 (F1) 130 receives a wireless transmission data frame including measurement data from the repeater 2 (F2) 140, the same processing as when the repeater receives is performed.
Finally, when the receiver 120 receives the data relayed from the repeater 1 (F1) 130, timer values corresponding to the number of relayed stages are embedded in the progress counter in the wireless transmission data frame.

  As a result, the time when the transmitter 110 transmits data, the time when the relay device 4 transmits data (reception counter (relay device 4)), and the time when the relay device 2 transmits data (reception counter (relay device 2)). The time when the relay device 3 transmits data (reception counter (relay device 3)) and the time when the receiver 120 receives data (elapsed counter) can be known based on the start of measurement.

  The wireless transmission data frame received is transmitted to the host system apparatus via the LAN (Local Area Network) so that the relay station number (ID) and the value embedded in the reception counter area of each relay station can be analyzed.

  The host system rearranges the timer value (with repeater number (ID)) embedded in the reception counter area in the received wireless transmission data frame and the RSSI value in order from the lowest timer value to form a form, and wirelessly transmits it. It is possible to display on the display screen what kind of communication path (relay route) the data of the data frame has passed.

  FIG. 9 is a diagram showing the determined communication path shown in FIG. 8 on the screen. As shown in FIG. 9, the communication path from the transmitter ID (01) to the receiver through the relays F4, F2, and F1 is determined in ascending order of the timer value, and the RSSI value at the time of reception is displayed in that order. The

Also, in the illustrated example, the relay 4 representing the number of relay stages has no numerical value, so that it can be seen that the relay 4 is not included in the relay.
FIG. 10 is a diagram illustrating an arrangement example of the wireless device according to the embodiment of the present invention in a building. FIG. 10 shows an arrangement example of wireless devices, that is, transmitters, receivers, and repeaters arranged at predetermined locations on the third to fifth floors of the building as an example.

In FIG. 10, for example, the receiver is disposed near the left ceiling of the room on the fourth floor, the repeater F2 is disposed at the center of the room on the second floor, and the repeater F4 is disposed at the center of the room on the fifth floor.
A transmitter is installed in each staircase on each floor, a repeater F1 is installed on the left staircase landing on the third floor, and a repeater F3 is installed on the staircase landing on the fourth floor left.

  In addition, each transmitter installed in the staircase on each floor operates corresponding to the transmitter 110 in FIG. 1, and each of the repeaters installed in the stair landing and in the center of the room is the relay in FIG. A receiver installed in the vicinity of the ceiling on the left side of the room on the fourth floor corresponds to any of the machines 130 to 160 and operates in correspondence with the receiver 120 in FIG.

The LAN connecting the receiver and the host system installed near the ceiling on the left side of the room on the fourth floor is not shown.
FIG. 11 is a diagram illustrating a state of wireless transmission in an example of arrangement of the wireless device illustrated in FIG. 10 in a building.

Transmission of measurement data from the transmitter to the receiver is realized by the construction and routing procedure of the sensor network described above.
Further, the RSSI (Received Signal Strength) value is measured at the time of data reception and is embedded in a predetermined area in the wireless transmission data format shown in FIG. Is omitted.

In FIG. 11, a solid arrow indicates that wireless data transmission / reception has been achieved including relay, and a broken arrow indicates that wireless data transmission / reception has not been achieved.
FIG. 12 is a diagram in which data received by the host system device via the receiver of the present invention and the data received on the screen is displayed on the floor map as shown in FIG.

  This screen example is the same type as the screen example shown in FIG. 9. The transmitter positions installed in the building are displayed on the left side of the figure, and the transmitter positions installed in the building are transmitted on the right side of the figure. The reception status of the data received by the receiver, that is, the RSSI value is displayed, and the RSSI value at the time of relaying of the relay device that is installed in the building from the left side to the right side of the figure and is involved in relaying is shown at the time of relaying Is also displayed.

  Referring to FIG. 12, since the RSSI value at the time of reception of the transmitter “E3A-4E-S4” installed on the fourth floor (4F) is not embedded anywhere, the receiver, the relay F2, the relay F4 It can be seen that communication has failed with any of the above.

  On the other hand, the transmitters “E3A-4E-S1” and “E3A-4E-S2” installed on the 4th floor (4F), when communicating from the relay F1 and the relay F3 to the receiver at the landing stage of the stairs When the RSSI value is confirmed, it can be seen that there is a margin (the received signal strength is strong).

In addition, the transmitter “E3A-4E-S3” installed on the fourth floor (4F) has no margin in the RSSI value at the receiver and is below −90 dBm, and if it is left unattended, a communication failure is expected.
Incidentally, the table of FIG. 12 shows a communication path (relay route) from the transmitter to the receiver on the floor map by the right arrow based on the result obtained in FIG.

FIG. 13 is a diagram illustrating an example of an RSSI trend at the time of receiving data transmitted from a transmitter installed on the fifth floor of the building displayed on the screen of the host system device.
In FIG. 13, the transmitter E3A-5E-S2 installed in the building 5F has an RSSI trend indicated by a rough broken line, and the transmitter E3A-5E-S3 installed in the building 5F is indicated by a fine broken line. The RSSI trend is shown, and the transmitter E3A-5E-S4 installed in the building 5F shows the RSSI trend as a solid line.

  FIG. 13 does not show the RSSI trend in all the transmitters shown in the left part of FIG. 12, but it can be understood how the RSSI trend in the sensor network system that the present invention pays attention to changes with time. Will.

FIG. 14 is a diagram illustrating a state of wireless transmission after the arrangement example of the wireless device illustrated in FIG. 11 is changed.
That is, FIG. 14 shows the measurement of the RSSI value in the receiver again in the same manner as described above by moving the receiver installed on the fourth floor (4F) shown in FIG. 11 to the center side. is there.

Similar to FIG. 12, the results are displayed side by side on the screen of the host system device via the receiver, and the result is shown in FIG.
FIG. 15 is a diagram in which data received by the host system device via the receiver of the present invention and the data received on the screen is displayed on the floor map as shown in FIG.

As shown in FIG. 15, the transmitters “E3A-3E-S1” and “E3A-3E-S2” installed on the third floor (3F) cannot communicate directly with the receiver.
However, it can be seen that what could not be communicated in FIG. 11 can be communicated in FIG. 15 via the relay machine F1 installed at the landing stage of the stairs.

In FIG. 11, the transmitter “E3A-4E-S4” installed on the fourth floor (4F) cannot communicate with the receiver, but in FIG. 15, it can communicate directly with the receiver. Yes.
Incidentally, the table of FIG. 15 shows, on the floor map, communication paths (relay routes) from the transmitter to the receiver moved to the center side by arrows based on the results obtained in FIG.

  As described above, the sensor network system to which the present invention is applied is in an area where the RSSI value assigned to each repeater is stored whenever the number of relays by the repeater increases between the transmitter 110 and the receiver 120. The embedded data will increase.

  However, when the receiver 120 receives the wireless transmission data frame, it is possible to read the RSSI value for each communication path and to obtain the temporal transition of the RSSI value in the entire sensor network.

  The receiver 120 sends the data in which the RSSI value is embedded in the received data frame to, for example, the host system device via the LAN, forms the data acquired by the host system device, and displays it on the screen. By viewing and analyzing this content, it is possible to evaluate the arrangement of the wireless devices and confirm that the arrangement is appropriate.

1 Sensor network 17 CT (current transformer)
18 VT (instrument transformer)
31 Intermittent operation control unit 32, 42, 52 Memory 33, 43, 53 Memory control unit 34, 45, 55 Data transmission / reception control unit 35 Communication unit 36 Host system device 37, 46, 57 Radio unit 38, 47, 58 Antenna 41, 51 Intermittent operation / time counter control unit 44, 54 Time counter unit 56 Measuring unit 110 Transmitter 120 Receiver 130 to 160 Repeater

Claims (6)

In a sensor network system having a mesh configuration, the sensor network system includes:
A transmitter having a measurement function and a wireless communication function and not having a relay function;
A repeater that does not have a measurement function and has a mesh relay function;
A receiver for transmitting and receiving radio waves between the transmitter and the repeater;
A host system connected to the receiver and having a function of observing at least each communication status of the sensor network; and
Consisting of
The transmitter is
Means for transmitting a beacon prior to the start of communication and selecting either a repeater or a receiver from the response;
Means for counting up a timer from the moment measurement is started and embedding a time required for transmission of measurement data as a counter value in a predetermined area of the data frame;
Means for embedding the ID of the own station in a predetermined area of the data frame;
Have
The repeater is
Means for measuring an RSSI value at the time of reception of a data frame transmitted by the transmitter and embedding the measured RSSI value in a predetermined area of the data frame allocated to the own station;
The data frame transmitted by the transmitter is received, the counter value embedded in the data frame is read, the timer built in the local station is counted up based on the value, and it is necessary for the relay transmission of the measurement data. Means for embedding the time as a counter value in a predetermined area of the data frame;
Have
The receiver
Means for measuring an RSSI value at the time of receiving a data frame transmitted by the immediately preceding relay or transmitter, and embedding the measured RSSI value in an area of the data frame allocated to the own station;
Means for receiving the data frame including the RSSI value, the counter value, and the repeater ID embedded in each of the repeaters involved until reaching the own station;
Means for sending the RSSI value measured by the own station, and a data frame including the RSSI value, the counter value, and the repeater ID received by the own station to a higher-level device;
Have
The host system apparatus displays an RSSI value for each communication path on the floor map of the screen based on the data frame transmitted from the receiver, and the contents are viewed and analyzed by an operator to analyze the receiver and the receiver. Evaluate the location of repeaters,
A sensor network system characterized by the above. Transmitter in a sensor network system of mesh configuration, the transmitter has a measurement function and a wireless communication function, but does not have a relay function,
A means for broadcasting a beacon before the start of communication, and selecting a partner having the strongest RSSI value from among the responses as a receiver of measurement data;
Means for counting up a timer from the moment when measurement of consumed power is started and embedding a time required for transmission of measurement data as a counter value in a predetermined area of the formatted data frame;
Means for embedding the ID of the own station in a predetermined area of the data frame;
Have
The transmitter measures power consumption and stores it in its own memory, reads the stored power data from the memory, embeds it in a predetermined area of the data frame, and transmits the data frame to a receiver at a predetermined cycle To
A transmitter characterized by that. A relay device in a sensor network system having a mesh structure, the relay device having a mesh relay function without a measurement function,
Means for measuring an RSSI value at the time of reception of a data frame transmitted by the transmitter and embedding the measured RSSI value in a predetermined area of the data frame allocated to the own station;
The data frame transmitted by the transmitter is received, the counter value embedded in the data frame is read, the timer built in the local station is counted up based on the value, and it is necessary for the relay transmission of the measurement data. Means for embedding the time as a counter value in a predetermined area of the data frame;
Have
The repeater relays and transmits the data frame to which the RSSI value embedded in the predetermined area of the data frame assigned to the own station, the updated timer counter value, and the repeater ID are added to the forward or lateral repeater. A repeater characterized by A receiver in a sensor network system having a mesh configuration, wherein the receiver transmits and receives radio waves between the transmitter and the repeater,
Means for measuring an RSSI value at the time of receiving a data frame transmitted by the immediately preceding relay or transmitter, and embedding the measured RSSI value in an area of the data frame allocated to the own station;
Means for receiving the data frame including the RSSI value, the counter value, and the repeater ID embedded in each of the repeaters involved until reaching the own station;
Means for sending the RSSI value measured by the own station, and a data frame including the RSSI value, the counter value, and the repeater ID received by the own station to a higher-level device;
Have
The receiver sends the received data frame to a host system connected to the local station via a LAN.
A receiver characterized by that. A host system apparatus connected to a receiver in a mesh sensor network system via a network, and the host system apparatus is connected to the receiver via a LAN,
The host system device is
Means for displaying an RSSI value for each communication path on the floor map of the screen based on the data frame transmitted from the receiver;
Means for displaying an RSSI trend at a specific transmitter on the screen based on the data frame transmitted from the receiver;
Have
The operator views and analyzes the content displayed on the screen to evaluate the arrangement position of the receiver and the relay,
A host system device characterized by that. A sensor network system includes a transmitter having a measurement function and a wireless communication function, not having a relay function, a relay having no measurement function and having a mesh relay function, and the transmitter and the repeater. Proper arrangement of wireless devices in a mesh-structured sensor network system comprising: a receiver that transmits and receives wireless radio waves between; and a host device connected to the receiver and having a function of observing at least each communication status of the sensor network A method,
The process of temporarily placing a wireless device including a transmitter, a repeater, and a receiver before determining the proper placement of the wireless device;
The process of constructing the network in the temporarily placed state and starting counting the timer of the transmitter when the measurement data is transmitted using the constructed network,
A process of measuring the updated value of the timer and the RSSI value at the reception time at the reception time in the relay connection until the measurement data reaches the receiver;
Embedding the updated timer value and the RSSI value in an area corresponding to the relay unit involved in the relay in a data format including measurement data at the reception time in the relay connection;
Sending a value embedded in each area in the data format received by the receiver to a higher-level device; and
The RSSI value in the network is displayed on the screen by the host system on the basis of the value embedded in each area in the transmitted data format, the contents are viewed and analyzed by the operator, and the wireless device on the network The process of determining the proper placement of
A method for properly arranging wireless devices in a sensor network system, comprising: