JP2006323440A - Information collection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information collection system enabling notification of the occurrence of abnormality with high accuracy in regard to the degree of relaxation of an electric wire extended between concrete poles. <P>SOLUTION: The information collection system includes an ultrasonic wave sensor for outputting a signal according to a distance to the ground, and a radio communication for transmitting the output information of the above ultrasonic sensor and the self-identification information. The information collection system further includes sensor nodes attached to the concrete poles; and a gateway server for collecting transmission information transmitted from the above sensor node, and transmitting the collected information to another communication network having a different communication protocol from the communication protocol for the sensor node concerned. Each sensor node constitutes a radio ad hoc network among sensor nodes mounted on other concrete poles existent within a communicable distance from the self-sensor node. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sag information system that collects sag information of overhead lines stretched on a con pole (electric pole) through a communication network.

Conventionally, as a device for observing the sag of an electric wire stretched on a power pole, a television camera and an image processing device to which an image signal of the electric wire output from the television camera is input are provided. And a pair of upper and lower windows that define the lower limit and the image signal of the electric wire are superimposed and displayed, and wire extension control that determines whether the slackness is within an appropriate range based on the positional relationship between this window and the electric wire A known slackness observation apparatus is known (see, for example, Patent Document 1).
Conventionally, as an overhead wire slack measurement device, a traveling device that travels over this overhead wire is provided, and this traveling device is equipped with an odometer that measures the traveling distance and an inclinometer that measures the inclination with respect to the horizontal. There is known a device for obtaining a current position of a traveling device in a coordinate system having one fulcrum as an origin from the inclination and obtaining a slackness from the current position (for example, see Patent Document 2).
Conventionally, the measurement of the sag of an electric wire has been done by using a long bar with a scale. The long bar is positioned vertically below the wire to be measured for sag, and the end of the bar is connected to the wire. It was done by measuring the height of the electric wire from the ground by adjusting to the height position.

JP-A-2-122207 JP-A-8-233568

In the work of stretching the electric wire on the power pole, the work is performed so that the sag representing the slack of the electric wire falls within the designed range. If the sag is reduced, the tension applied to the wire itself increases, increasing the risk of disconnection and the like. On the other hand, if the sag is increased, the tension applied to the electric wire itself is reduced and safety is increased, but there is a problem that a necessary distance from the building under the line cannot be secured.
In this way, even if the slack of the electric wire is within the design range in the initial stage, the wire rod extends and the slack is promoted with the time used for power transmission, so there is a risk of contact with the building under the line, In addition, if the slack disappears for some reason, there is a risk that the electric wire is disconnected.
It was actually impossible to observe the sag by installing a TV camera on the wires for this purpose. In addition, the measurement of the sag takes apparatus and manpower, and the sag of all wires cannot be measured and monitored.
The present invention was made to solve such problems, and has an object to obtain a sag information collection system that can constantly monitor the sag of an electric wire and immediately report the occurrence of the abnormality. To do.

  The sag information collection system according to the present invention includes an ultrasonic distance sensor that outputs a signal corresponding to a distance from the ground, and a wireless communication unit that transmits output information of the ultrasonic distance sensor and self identification information. A sensor node attached to the control pole, and a gateway server that collects transmission information transmitted from the sensor node, and transmits the collected information to another communication network with a communication protocol different from that of the sensor node. The sensor nodes constitute a wireless ad hoc network with the sensor nodes mounted on other control poles existing within a communicable distance.

  According to the present invention, sensor collection information can be transmitted by ad hoc multi-hop communication using sensor nodes provided in other connected pillars in the surrounding area. Abnormalities can be reported immediately.

Embodiment.
FIG. 1 is a diagram showing a configuration of a sag information collection system according to Embodiment 1 of the present invention.
In the figure, a connecting pole 1 is a power pole that supports an electric wire 2, a communication cable, and the like, and is installed at intervals of 50 m to 200 m. The sensor node 3 is installed in each of a plurality of connected pillars 1 arranged in a desired area where information is collected, such as a residential area, an industrial area, and a commercial area. The sensor nodes 3 are installed in all the connected pillars 1 that need to be monitored for collapse. The sensor node 3 is attached to the upper part of the connecting pillar 1.

  The sensor node 3 performs network communication using an ad hoc multi-hop communication technique. In ad-hoc multi-hop communication, sensor nodes 3 adjacent to each other perform wireless communication with each other, and cooperate with each other to build a multi-hop transfer route autonomously, thereby constructing a network (wireless ad hoc network). To do. Thereby, each sensor node 3 can relay and communicate data from the slave station (sensor node) to the master station (gateway server) through the wireless ad hoc network.

  As a communication protocol of the sensor node 3, a low transmission power radio such as a specific low power radio or ZigBee (IEEE 802.15.4) is used. The specific low-power radio has communication characteristics of a communication frequency of 429 MHz, a transmission speed of 2.4 Kbps, a transmission distance of about 50 m to 300 m, and a power consumption during communication of 50 mW or less (standby power of 0.3 mW or less). It is characterized by low communication power.

The gateway server 5 is installed on a specific pillar 1. The gateway server 5 is connected to a communication network 7 through a communication cable 6 such as an optical communication cable, a telephone line such as ISDN or ADSL, or a coaxial cable for cable television. The gateway server 5 transmits information collected from the surrounding sensor nodes 3 via the wireless ad hoc network 120 to the upper communication network 7. The gateway server 5 functions as a gateway that performs protocol conversion between the wireless ad hoc network 120 and the communication network 7.
Needless to say, the gateway server 5 may be installed in a structure other than a steel pillar, a roof of a building, or the like.

  The sensor node 3 is connected to an ultrasonic distance sensor 34 (described later) installed on the electric wire with an attached cable, measures the distance between the electric wire position and the ground, and collects it as detection information. The sensor node 3 may include a plurality of sensors other than the ultrasonic distance sensor.

The ultrasonic distance sensor 34 includes a transmission unit and a reception unit, and the ultrasonic wave emitted from the transmission unit is reflected by the ground, returns to the ultrasonic distance sensor, and is received by the reception unit. The ultrasonic distance sensor 34 includes an ultrasonic transmission unit and an ultrasonic reception unit, and measures a round-trip time required for propagation of ultrasonic waves between the transmission / reception unit and the ground. The distance to the ground can be calculated from 1/2 of the round-trip time and the value of sound velocity. Here, it is known that the speed of sound changes greatly depending on the ambient temperature, and the fluctuation value is about 0.078% / ° C. Therefore, the ultrasonic distance sensor incorporates an ambient temperature compensation circuit capable of measuring the ambient temperature and reflecting it in the distance calculation formula so as not to cause an error in the distance calculation.
In addition, since the ultrasonic distance sensor measures the distance from the ground, it is desirable that the ultrasonic distance sensor is constantly directed downward in the vertical direction. If the direction is deviated from the vertical due to strong wind, an error occurs in the distance measurement. Therefore, it is desirable that the ultrasonic distance sensor has a measure to withstand strong winds, for example, a weight is attached, or a measure is taken such that it is cylindrical so as not to receive wind pressure as much as possible.

The sensor node 3 at the end (the sensor node 3 installed on the column 1c in the example of FIG. 1) and the sensor node 3 at the base connected to the gateway server 5 (the sensor installed on the column 1a in the example of FIG. 1) A plurality of sensor nodes 3 interposed between the node 3) and the wireless ad hoc network 120.
The wireless ad hoc network of this embodiment is also called a sensor network because the sensor node 3 has sensors and each sensor autonomously constructs a network.
Data (detection information) detected by each sensor of an arbitrary sensor node 3 is sequentially relayed (hopped) by other sensor nodes 3 constituting the wireless ad hoc network 120, and from the terminal sensor node 3 (upstream side). The data is sequentially transmitted in a relay manner toward the root sensor node 3 (downstream side) connected to the gateway server 5.

When each sensor node 3 constituting the wireless ad hoc network 120 relays detection information collected by each sensor from the upstream side to the downstream side, for example, the terminal sensor node 3 first starts data transmission. 1 to the gateway server 5, the next downstream sensor node 3 starts data transmission and performs data transmission to the gateway server 5. Then, each sensor node 3 sequentially transmits data and transfers data to the gateway server 5 from upstream to downstream, and finally, the root sensor node 3 transmits data to the gateway server 5.
Note that it takes a predetermined communication time for all the sensor nodes 3 constituting the wireless ad hoc network 120 from the end to the base to complete transmission of all detection information collected by each sensor. The number of sensor nodes 3 constituting 120 is naturally limited according to the transmission rate and transmission amount of data.

A wireless ad hoc network 120 constituting one group is connected to the gateway server 5 by a predetermined number of sensor nodes 3.
In addition, a plurality of groups of wireless ad hoc networks that form a network independently of each other may be connected to one gateway server 5. That is, the gateway server 5 may constitute a multi-channel, and a plurality of root sensor nodes 3 may be connected to each channel of the gateway server 5.

  The gateway server 5 is connected to the database 8 through the communication network 7. In the database 8, detection information of each sensor node 3 collected by the gateway server 5 is stored and accumulated. The database 8 transmits the detection information transmitted from the gateway server 5 and stored therein to the information center 9.

  The information center 9 processes the detection information of the sensor node 3 stored in the database 8. Specifically, the sag information of each electric wire stored in the database 8 is compared with a preset threshold value, an electric wire whose sag is equal to or greater than the threshold value is extracted, and the sag information is displayed on the display unit 100. A warning is displayed when an abnormality occurs. In addition, the data mining process of the detection information is performed to obtain some useful processing information.

  The user terminal 11 is connected to the information center 9 through another communication network 7 or a communication network 10. Processing information obtained by the data mining processing of the information center 9 is transmitted to the user terminal 11.

FIG. 2 is a diagram illustrating the configuration of the sensor node 3.
In the figure, the sensor node 3 includes a wireless communication unit 30 and a sensor unit 31 connected to the wireless communication unit 30.
The wireless communication unit 30 includes an antenna unit 23, a wireless modulation unit 24, a control unit 25, a power supply unit 27, a battery 28, an external power supply port 29, an interface unit 32, and a memory 33.
The sensor unit 31 includes an ultrasonic distance sensor 34, another sensor 35 (first sensor), an external sensor 37 (second sensor), and an external sensor connection port 36.
The sensor unit 31 may be connected to the wireless communication unit 30 through a signal line, or may be wirelessly connected by infrared rays, a wireless LAN, or the like. Of course, the sensor unit 31 may include a wireless communication unit therein, and a sensor node separate from the wireless communication unit 30 may be configured.

  Of course, in order to further improve the communication volume and communication speed, a transmission / reception antenna having beam directivity from the horizontal direction to the diagonally downward direction may be used. In this case, the antenna unit 23 is appropriately formed with an antenna beam pattern so that the upper part of the con pillars arranged around the antenna unit 23 falls within the directivity angle.

  The radio modulation unit 24 demodulates an RF (Radio Frequency) signal received by the antenna unit 23, converts the received signal into a digital signal, and reproduces transmission information. The reproduced information is sent to the control unit 25. Further, the transmission signal generated by the control unit 25 is modulated into an RF signal and radiated from the antenna unit 23 to the space. Thereby, it is possible to communicate with other sensor nodes 3 via the antenna unit 23.

The control unit 25 includes a microcomputer and various memories.
The control unit 25 has a specific low-power wireless communication protocol, and includes a communication control unit 240 that performs communication control of the wireless modulation unit 24.
The communication control unit 240 includes a network protocol that performs various data access processes such as access control, channel allocation, path control (communication route determination), and error control, ad hoc communication processes, and multi-hop processes.

In addition, the control unit 25 includes a data processing unit 26 for data processing of detection information from the sensor unit 31.
The data processing unit 26 controls the operation of the sensor unit 31 through the interface unit 32. Thereby, the control unit 25 collects detection information of the sensor unit 31. Based on the distance calculated from the measurement data of the ultrasonic distance sensor, the data processing unit 26 calculates the sag of the electric wire by subtracting the distance from the height of the con pillar. The data processing unit 26 appropriately processes the collected detection information of the sensor unit 31 and then converts it into packet data. The packet data is subjected to communication control by the communication control unit 240 and transmitted to the wireless modulation unit 24.

  In addition, the control unit 25 includes a power control unit 260 that controls power supplied from the power supply unit 27. The power control unit 260 performs dynamic power control focusing on data collection from the sensor unit 31 and wireless communication operation. For example, by periodically grasping the operating state of the terminal, based on the grasped result, by dynamically controlling the power on / off control of each functional part and switching the clock frequency of the processor, finely controlling the power, Reduce power consumption.

  The power supply unit 27 supplies the power of the battery 28 or the power of the external power supply 29 to the control unit 25. That is, the connection between the battery 28 and the external power source 29 is switched. Normally, the power source of the external power source 29 is used, but when the external power source 29 is cut off and the power of the external power source 29 is detected using a voltmeter or the like, the power source is automatically switched to the battery 28. That is, the power supply unit 27 functions as an uninterruptible power supply.

As the battery 28, a button battery or a storage battery that automatically charges the battery 28 according to the discharge state is used. Moreover, you may utilize environmental energy like a solar cell.
The external power supply 29 draws out the transmission power of the electric wire 2, performs a transformation process, and takes out the power supply.
When a solar cell is used as the battery 28, the external power source 29 may not be used. In this case, a storage battery for accumulating electric power for use at night is used in combination.

The interface unit 32 is connected to a memory 33, an ultrasonic distance sensor 34, and another sensor 35. Further, an external sensor connection port 36 for connecting an external sensor 37 is provided.
The interface unit 32 temporarily stores the detection information output from each sensor in the memory 33. The memory 33 functions as a buffer, and the detection information stored in the memory 33 is transferred to the control unit 25 at a predetermined timing.
The control unit 25 controls the timing of data transfer and the priority of data to be transferred.
The interface unit 32 converts detection information acquired from each sensor into a digital signal and performs data transfer.

The memory 33 has a different memory area for each sensor, and includes, for example, an SDRAM. Information detected by the ultrasonic distance sensor 34 is accumulated in a specific memory area of the memory 33 as needed.
The memory 33 is used as an external memory managed by the control unit 25 in addition to a function as a buffer. Various initial data are stored in the memory 33. For example, the identification code (node ID) of the sensor node 3, the identification code (sensor ID) of each sensor connected to the connection port of the interface unit 32, and the type information (sensor type information) of each sensor are stored. .
The sensor type information indicates the type of sensor to be connected, and is set as appropriate, for example, the code 1 is assigned to the ultrasonic distance sensor 34.
The sensor ID is used by the control unit 25 to grasp the sensor connection status at each connection port of the interface unit 32.

In addition, the memory 33 stores the node ID of the partner sensor node 3 for sequentially performing the data link in accordance with the established communication path of the sensor node 3.
For example, when the wireless wireless ad hoc network 120 is configured by interposing three sensor nodes in the communication path between the terminal sensor node 3 and the gateway server 5, the node IDs for the three are stored in the memory 33. Is done. In addition, the arrangement order of the sensor nodes along the communication path is also stored at the same time. These pieces of information are acquired by communicating with other sensor nodes 3 in the initial connection stage for configuring the wireless wireless ad hoc network 120.
The communication order of each sensor node is set so that, for example, data transfer is sequentially performed in a relay manner from the sensor node 3 at the end toward the sensor node 3 on the gateway side through the sensor node 3 interposed therebetween. The Each sensor node 3 manages a common communication order according to the order in which the node IDs are arranged. This communication order is stored in the memory 33.
In addition, the memory 33 can read and write various information necessary for various controls of the control unit 35.

The interface unit 32 transfers the detection information of the ultrasonic distance sensor 34 to the control unit 25 at a predetermined period synchronized with the internal clock.
Further, the control unit 25 repeatedly generates a start signal (trigger signal) intermittently at a predetermined interval in synchronization with the internal clock, and sends it to the interface unit 32.
When receiving the activation signal, the interface unit 32 transfers the detection information of the sensor 35 to the control unit 25. That is, the detection information of the sensor 35 is output to the control unit 25 repeatedly and intermittently. The output period of the detection information by the sensor 35 is preferably longer than the output period of the measurement information by the ultrasonic distance sensor 34. However, the output period may be set as appropriate depending on the transmission priority of necessary information.

As described above, according to the present invention, sensor collection information can be transmitted by ad-hoc multi-hop communication using sensor nodes provided in other control poles existing in the surroundings. It is possible to monitor constantly and report the occurrence of abnormality immediately.

  As another aspect, instead of the ultrasonic distance sensor, a laser distance sensor may be used to measure a round-trip time during which the laser propagates and calculate a distance to the ground. In this case, since the speed of light is not affected by the ambient temperature, an ambient temperature compensation circuit becomes unnecessary.

Based on the distance calculated from the measurement data of the ultrasonic distance sensor, the sag of the electric wire can be calculated by subtracting the distance from the height of the column. This calculation is performed at each sensor node.
Each sensor node transmits a sag calculation result from the wireless communication unit. When the sag calculation result exceeds a certain allowable value, an alarm signal is transmitted.

  In the above description, the sag calculation is performed at each sensor node. However, the distance measurement data itself may be sent to the information center and the sag calculation may be performed at the information center.

  In FIG. 1, the ultrasonic distance sensor and the sensor node are connected by wire. However, as shown in FIG. 3, the sensor node and the ultrasonic distance sensor are integrated and installed at the center of the electric wire. Also good. In that case, there is no need to provide a long cable between the sensor node and the ultrasonic distance sensor.

  Further, as shown in FIG. 4, communication between the sensor node and the ultrasonic distance sensor may be performed by wireless communication 2 that is different from wireless communication 1 between the sensor nodes, instead of wired communication. The wireless communication 2 may be different from the wireless communication 1 only in frequency or may be weak wireless band communication that does not require another license.

1 is a configuration diagram of a sag information collection system according to an embodiment of the present invention. It is a block diagram of the sensor node which concerns on embodiment of this invention. It is a block diagram of the looseness information collection system which concerns on the other form of this invention. It is a block diagram of the looseness information collection system which concerns on the other form of this invention.

Explanation of symbols

  1 pillar, 2 electric wires, 3 sensor nodes, 5 gateway server, 7 communication network, 8 database, 9 information center, 11 user terminal, 30 wireless communication unit, 31 sensor unit, 34 ultrasonic distance sensor, 120 wireless ad hoc network.

Claims (4)

A distance sensor that outputs a signal according to the distance between the overhead wire and the ground; a wireless communication unit that transmits the output information of the distance sensor and its own identification information; and a sensor node attached to the con pillar;
A gateway server that collects transmission information transmitted from the sensor node, and transmits the collected information to another communication network having a communication protocol different from that of the sensor node.
The information collection system according to claim 1, wherein the sensor node forms a wireless ad hoc network with a sensor node mounted on another control pole existing within a communicable distance. The transmission information transmitted from the gateway server is received via another communication network, and based on the sensor detection information and the sensor node identification information included in the reception information, a threshold value at which sag fluctuation is set in advance is set. The information collection system according to claim 1, further comprising a management center that outputs information for specifying the wires that have passed. 3. The information collecting system according to claim 1, wherein the distance sensor is suspended from the overhead line, and the distance sensor is cable-connected to the sensor node. The information collection system according to any one of claims 1 to 3, wherein the distance sensor is an ultrasonic sensor.

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