JP2006074536A - Sensor network system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To immediately construct a network by grasping the location of each sensor constituting a sensor network. <P>SOLUTION: Each sensor constituting first and second sensor groups is provided with a self-position measuring means by a GPS (global positioning system) and measures a self-position. Self-positions are sequentially transmitted by radio waves through a sensor network constructed by ad hoc communication, an optical beam communication means transmits the self-positions from the second sensor group to a communication station, and the communication station records the self-positions. The communication station quickly grasps the position of each sensor. The communication station uses wide-angle communication from the second sensor and can easily establish connection. A position information correcting means obtains an accurate position about a position obtained by the self-position measuring means, the correction of the position is performed on the basis of to an area surrounded by positioning data at a plurality of reference points and to an area surrounded with the plurality of position reference points, and the position can be evaluated with very correct accuracy. In an optical beam communication network, laser beams are used to make long distance communication possible. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a network system for arranging a plurality of sensors and collecting information detected by the sensors through a network.

  There is a network system for arbitrarily arranging a plurality of sensors and collecting information detected by the sensors through a network. When sensors are distributed over an area of a certain size and sensor information is collected or collected at each point, the position of each sensor to be placed is grasped, and the sensor target is detected at that position. It is necessary to confirm. Furthermore, when the collected or collected information is transmitted to other places by communication means using light, it is efficient to grasp the position of the communication terminal responsible for transmission / reception of light with high accuracy. Necessary to establish transmission / reception.

The problem to be solved is that the arrangement position of each sensor constituting the sensor network, in particular, the arrangement position of the terminal that performs transmission and reception using light is grasped with high accuracy, and the network is immediately constructed.
That is, when at least one of at least one pair of terminals for performing transmission / reception using light is arbitrarily arranged like the sensor, the terminal has means capable of automatically adjusting the transmission / reception direction. In addition, it is indispensable to accurately grasp the arrangement in order to establish transmission and reception by light.

In order to solve the above problems, a sensor network system according to claim 1 includes a plurality of first node groups including sensor means, self-position measuring means using GPS, and wireless transmitting / receiving means corresponding to all azimuth angles by radio waves; Self-position measuring means by GPS, wireless transmitting / receiving means corresponding to all azimuth angles by radio waves, light beam transmitting means using a narrow-angle light beam, and light beam transmission direction adjusting means for adjusting the transmission direction of the light beam transmitting means, A plurality of second node groups having light beam receiving means corresponding to all azimuth angles, light beam transmitting / receiving means communicating with the second node via the light beam transmitting / receiving means, and adjusting the light beam transmitting / receiving direction And a communication station including a light beam transmission / reception direction adjusting means and a self-position measuring means by GPS.
The sensor network system according to claim 1 operates as follows. First, the first node group and the second node are dispersed at arbitrary positions. At this time, a sensor network is automatically constructed by an ad-hoc communication method, and the second node is set as a core. Constitute a cluster. In the cluster, the self-position information measured by the self-position measuring means provided in each node and the sensor information by the sensor provided in each node are collected to the second node by the ad hoc communication. In addition, commands related to sensor operation, operation method, sensor information transmission method, and the like are transmitted from the second node to each first node group by the ad hoc communication. Further, the second node and the communication station are configured to transmit and receive information by means of a light beam transmission / reception means, and the communication station finally has each position information and sensor information of the first node group. Can be obtained via the second node. Also, commands such as the operation of the sensor, the operation method, and the sensor information transmission method can be transmitted to the first node group via the second node.
In the transmission / reception by the light beam, a pair of transmission / reception terminals are usually installed in a predetermined arrangement and used in a condition in which the transmission / reception direction is clear to some extent. Since the nodes are scattered at arbitrary positions, it is difficult to establish transmission and reception by the light beam. For this reason, the sensor network system according to claim 1 receives the light beam corresponding to the omnidirectional angle provided in the second node by sweeping the light beam with the self-position information acquired by the communication station by GPS. The second node communicates with the second node via the means, and the second node transmits and receives light from the position information and its own position information measured by the self-position measuring means using GPS provided in the second node itself. And the light beam transmission direction adjustment means for adjusting the transmission direction of the light beam transmission means to adjust the transmission direction of the light beam transmission means, thereby establishing light beam communication between the communication station and the second node. Thus, it is characterized in that light beam communication can be established efficiently at an early stage. In addition, in the sensor network according to the present invention, the battery life of the node becomes a big issue, while the light beam sweeping process when establishing the light beam transmission / reception at the initial stage needs to spread the beam to a certain wide angle and transmit it. However, in the system according to claim 1, since the communication station (usually having sufficient power capacity such as a base station) is responsible for this process, the problem concerning the battery life of the node is also cleared. This is also a feature of the sensor network system according to claim 1.
In the above description, the case where there is one second node has been described. However, a plurality of the second nodes are formed, and a plurality of clusters having each node of the second node group as a nucleus are formed. By doing so, a wider range of information may be obtained.

  A sensor network system according to a second aspect is the one according to the first aspect, wherein the second node group includes a wide-angle communication means using light diffusion or radio waves using a wide-angle beam, and among the second node group, Self-position information measured by self-position measuring means of at least one node is configured to be delivered from the second node to the communication station using wide-angle communication means.

  Further, the sensor network system according to claim 3 is the one according to claim 2, wherein when the self-location information is delivered from the second node to the communication station using the wide-angle communication means, directly or via the relay means. To be delivered.

According to a fourth aspect of the present invention, there is provided the sensor network system according to the third aspect, wherein the relay unit is a node distribution unit that moves in the air and includes a relay wireless transmission / reception unit.
For example, when the first node group and the second node group dispersed by the node spreading means are dispersed, the position information measured by the self-position measuring means provided at least for each second node is The information is transmitted to the node spreading means, that is, the relay means by the wide-angle communication means provided for each second node. The relay means transmits position information related to the second node to the communication station by the relay wireless transmission / reception means.

  The sensor network system according to claim 5 is the sensor network system according to any one of claims 1 to 4, wherein the communication station uses the self-position measuring means of each node of the first node group and the second node group. The measured self-position information and the sensor information by the sensor means provided at each node are obtained via the second node group.

A sensor network system according to a sixth aspect of the present invention is the sensor network system according to any one of the first to fifth aspects, wherein the communication station includes position information correction means based on correction information calculated from the positioning information of the position reference point. It is.
The communication station includes position information correction means based on correction information calculated from the positioning information of the position reference point, and corrects at least the position information of each second node and the position information of the communication station itself by the position information correction means. And each highly accurate position information is acquired.

  The sensor network system according to claim 7 is the sensor network system according to any one of claims 5 to 6, wherein the position information correction means is based on positioning data at a plurality of reference points and the plurality of position reference points. It is characterized in that correction is performed on a region surrounded by.

  According to an eighth aspect of the present invention, there is provided the sensor network system according to any one of the first to seventh aspects, wherein a laser beam is used as a light beam communication means using a narrow-angle light beam. .

According to the sensor network system of claim 1, each node of the first and second node groups includes a self-position measuring unit using GPS, whereby self-position can be measured, and the self-position information is ad hoc. In the sensor network constructed using communication, the data is collected to a predetermined second node in a bucket relay manner, and transmitted from the second node to the communication station by the light beam transmitting / receiving means. In the process of establishing the light beam communication, the second position is prepared by sweeping the light beam from the light beam transmitting / receiving means by the light beam transmitting / receiving direction adjusting means with the self-location information acquired by the communication station by GPS. Is transmitted to the second node via the light beam receiving means corresponding to all azimuth angles, and the second node is transmitted by the position information about the communication station and the self-position measuring means by GPS provided in the second node itself. By determining the light transmission / reception direction from the measured position information, and adjusting the transmission direction of the light beam transmission means by the light beam transmission direction adjustment means for adjusting the transmission direction of the light beam transmission means, the communication station And light beam communication between the second node and the second node can be established quickly and efficiently.
Further, the light beam sweeping process when establishing the transmission and reception of the light beam in the initial stage requires a large amount of energy because it is necessary to spread the beam to a certain wide angle and transmit it. For example, at the stage where light beam communication is established, assuming that the divergence angle of the light beam is 1 milliradian, the beam area of 1 m ² is 1 km away, and for example, optical communication can be selectively performed with nodes scattered in units of 10 m. However, in the initial light beam sweeping process, for example, it is assumed that the second node must be searched from among the nodes scattered over 1 km × 1 km, and the light beam is assumed to be swept with a beam area of 50 m × 50 m. 2,500 times as much energy as communication is required. In the sensor network system, it is said that the battery life of the node is a major issue. However, in the sensor network system according to claim 1, a beam sweep process for establishing light beam communication is performed by a communication station (usually a base station). The problem of the battery life of the node can be solved because the station, which has sufficient power capacity such as a station, is responsible.

  According to the sensor network system of claim 2, when the self-position information measured by the self-position measuring means is delivered from the second node, the wide-angle communication means for delivering to the communication station by light diffusion using a wide-angle beam or radio waves is used. Therefore, even if the delivery destination is far away, information can be transmitted and received without accurately positioning the delivery destination.

  According to the sensor network system of the third aspect, when the self-position information is delivered from the second node to the communication station using the wide-angle communication means, it can be delivered directly or via the relay means.

  According to the sensor network system of claim 4, when the first node group and the second node group distributed by the relay means, that is, the node distribution means are dispersed, the relay means is at least from the second node. The position information of each of the nodes is acquired by the wide-angle communication means provided for each of the second nodes, and the relay means transmits the position information regarding the second node to the communication station by the relay wireless transmission / reception means. it can.

  According to the sensor network system of claim 5, the communication station includes not only the self-position information measured by the self-position measuring means of each node of the first node group and the second node group but also sensor means provided in each node. Sensor information according to can also be obtained via the second node group.

  According to the sensor network system of claim 6, the communication station includes position information correction means based on correction information calculated from the positioning information of the position reference point, and the position information of each second node and the position information of the communication station itself are obtained. Correction is performed by the position information correction means, and each position information can be acquired with high accuracy, and information can be immediately transmitted and received between the communication station and the predetermined second node using a narrow-angle light beam.

The sensor network system according to claim 7 is configured such that the position information correction unit corrects the region surrounded by the plurality of position reference points based on the positioning data at the plurality of reference points. Ordinary DGPS (Differential GPS) corrects position information based on information of a single reference point. Therefore, if the measured position is too far from the reference point, the propagation distance and propagation angle in the ionosphere and the atmosphere related to radio waves from the satellite will differ between the reference point and the measured position. The value lacks legitimacy. Usually, when the reference point and the actual measurement position are separated by 5 km or more, the correction error rapidly increases.
According to the sensor network system of the seventh aspect, since the correction is performed on the area surrounded by the plurality of position reference points based on the positioning data at the plurality of reference points, the correction information of the measured position is obtained. Since the calculation is performed by interpolation from the respective reference points at positions surrounding the position, it is possible to perform highly accurate position information correction. An experimental result has been obtained that the position can be obtained with an accuracy of several centimeters if the area surrounded by the reference point is within 100 km × 100 km (normal GPS positioning has an error of 10 m to 30 m).

  According to the sensor network system of the eighth aspect, long distance communication of several tens km can be performed by using laser light as a light source for light beam communication.

FIG. 1 is an overview layout diagram of an embodiment of the system of the present invention, showing an example of a system for detecting enemy units deployed in a certain area, 101 is a first node group, and 102 is a second node. , 103 is a communication station, 104 is an unmanned airplane, also referred to as UAV, 105 is a command and control vehicle, 106 is an artificial satellite, 107 is a position reference point, 108 is an infantry infantry unit, and 109 is an enemy unit vehicle It is.
FIG. 2 shows a functional block diagram of the first node group 101, the second node group 102, and the communication station 103.
The first node group 101 includes sensor means 1011 for sensing a predetermined target, self-position measuring means 1012 using GPS, and wireless transmitting / receiving means 1013 using radio waves (FIG. 2A). A plurality of first node groups 101 are arranged, and each sensor means 1011 senses not only the same sensing object but also a different object depending on its purpose.
The second node group 102 includes a GPS self-position measuring unit 1022, a radio transmission / reception unit 1023, a wide-angle communication unit 1024 suitable for light diffusion using a wide-angle beam or a medium distance using a radio wave, and laser light. And light beam communication means 1025 suitable for narrow-angle long distance using a beam. The light beam communication means 1025 includes a light beam transmission / reception means 1026 for all azimuth angles and a light beam transmission direction adjustment means 1027 for adjusting the transmission direction of the light beam transmission / reception means 1026. Further, when the second node itself is also used as a sensor terminal, it may be provided with sensor means 1021 for sensing a predetermined target (FIG. 2B). A plurality of second node groups 102 are arranged, and each of the sensor means 1021 is not necessarily limited to the same sensing object, but senses different objects depending on the purpose, and sensor means 1011 of the first node group 101. May have the same sensor function.
The sensor means 1011 of the first node group 101 and the sensor means 1021 of the second node group 102 detect movement of an enemy by magnetism, vibration, sound, etc., or detect chemical weapons or biological weapons according to their purposes. Use what you want. Further, these node groups 101 and 102 have an identification code ID for distinguishing individual nodes.
The communication station 103 is mounted on a reconnaissance vehicle, and communicates via the light beam transmitting / receiving means 1025 of the second node group 102, self-position measuring means 1032 by GPS, and the first node group. The sensor information recording unit 1033 that records the self-position information and sensor sensing information measured by the self-position measuring means of each sensor of the 101 and the second node group 102, and the correction information calculated from the positioning information of the position reference point 107. Position information correction means 1034 for correction is provided (FIG. 2C). The light beam communication means 1031 includes light beam transmission / reception direction adjusting means 10312 for adjusting the transmission / reception direction of the light beam. When a plurality of communication stations 103 are provided, the communication stations 103 form a communication network with each other. Furthermore, each of these communication stations 103 may distinguish the person in charge according to the sensing object or the location area of the sensor means 1011 and the sensor means 1021.
The reconnaissance vehicle communication station 103 stops at an appropriate distance from the front line, measures its position by the self-position measuring means 1032, and obtains a positioning result from one or more position reference points 107 nearby. The position reference point 107 is a GPS reference point, and the position is known. The position information correcting unit 1034 extracts a positioning error from the positioning result with respect to the position reference point 107 and the known position information of the position reference point 107, obtains the positioning error as correction information, and obtains a measured value from the self-position measuring unit 1032. Is corrected using the correction information to obtain a more accurate position. Similar error correction is performed on the positional information of the first node group 101 and the second node group 102 sent via the second node group 102, and the respective accurate positions are obtained. When the correction information is obtained from the two position reference points 107, the directions of the position reference points 107 are positioned in opposite directions so as to sandwich the first node group 101, the second node group 102, and the communication station 103 as much as possible. What to do is desirable. When correction information is obtained from three or four or more position reference points 107, the first node group 101, the second node group 102, and the communication station 103 are in an area surrounded by these position reference points 107. In this manner, the position information correction unit 1034 calculates an error map at each position in the area. Based on the calculated error map, the measured value from the self-position measuring means 1032 is corrected using the correction information to obtain a more accurate position.
The UAV, that is, the unmanned airplane 104 includes a relay wireless transmission / reception means 1041 suitable for a medium distance by light or radio waves (FIG. 2D), communicates with the wide-angle communication means 1024 of the second node group 102, and the information And the first node group 101 and the second node group 102 are carried and mounted.

(Step 1)
First, the UAV 104 is arranged by spreading the first node group 101 and the second node group 102 in an area where an enemy is expected to develop. At this time, based on the fact that the communication distances of the wireless transmission / reception means 1013 and 1023 included in these devices are several meters to several hundreds of meters, the distances are dispersed so as to allow mutual communication. The distributed first node group 101 and second node group 102 automatically start mutual communication with neighboring nodes by using the wireless transmission / reception means 1013 and wireless transmission / reception means 1023 respectively equipped. A sensor network system is constructed by a so-called ad-hoc communication method. That is, a state in which a plurality of first nodes are connected by a network (hereinafter referred to as “cluster”) with one second node as a core is completed, and a plurality of clusters are further connected by a network. A system is built. This system can be built automatically within seconds to minutes.
On the other hand, each first node group 101 measures its own position by the self-position measuring means 1012 provided therein, and outputs the measurement result together with the identification code ID, initial sensor information, time, and the like. These pieces of information are sequentially transferred in a bucket relay manner in the sensor network system and collected as data in the second node 102 serving as a core. The second node 102 itself measures its own position by the self-position measuring means 1022 and, if it has the sensor means 1021, includes the sensor initial information and adds it to the data together with its own identification code ID.

(Step 2)
After that, at an appropriate time, the second node group 102 uses the wide-angle communication means 1024 for performing the light diffusion communication using the wide-angle beam or the communication by the radio wave, and the relay wireless suitable for the intermediate distance by the light or the radio wave provided in the UAV 104. The UAV 104 communicates with the transmission / reception means 1041, and as a relay means, the UAV 104 acquires position information regarding the second node group 102 and transmits the position information to the communication station 103. When it is possible to fly in the vicinity of the second node group 102 dispersed by the UAV 104 (for example, a distance of several tens of meters to several hundreds of meters), the relay wireless transmission / reception means 1041 is a radio wave included in the second node group. Communication with the wide-angle communication means 1024 that performs communication according to the above, and when the flight altitude is high and the wireless transmission / reception means 1023 cannot reach (for example, several hundred meters to 1 km), the wide-angle communication by the light diffusion communication provided in the second node group Communication is performed with the means 1024. Needless to say, when the communication station 103 itself is located in the vicinity of the second node group, the position information may be directly transmitted between the second node group 102 and the communication station 103 without using the UAV 104. Yes. The communication process described in Step 2 may be performed once for the second node 102 at the time of spreading, and does not need to be continued.
Through the above steps, the communication station 103 can grasp the number of effective second node groups 102 and their positions. However, the position information includes an error of about 10 m to 30 m (hereinafter referred to as “schematic position information”). The communication station 103 calculates correction information from the positioning information related to one or a plurality of position reference points 107 by the provided position information correction unit 1034, and corrects the approximate position information using the correction information, thereby accurately. Position information can be obtained. The position information has an error of several centimeters (hereinafter referred to as “high-precision position information”). Such information is recorded in the sensor information recording unit 1033.

(Step 3)
The light beam communication means 1031 of the communication station 103 adjusts the light beam transmission / reception direction adjustment means 10312 based on the recorded high-accuracy position information of the second node group 102, and a narrow-angle light beam toward the position, for example, Send an optical signal by laser light. The communication distance between the communication station 103 and the light beam communication means 1025 of the second node group 102 can be 5 km to 20 km. The second node group 102 that has received the optical signal by the installed light beam transmitting / receiving unit 1026 for all azimuths uses the light beam transmission direction adjusting unit 1027 provided in the light beam communication unit 1025, for example, a mirror. And an operation for enabling communication such as directing the optical transmitter in the direction of the communication station 103 is performed according to a control command included in the optical signal. After the optical beam communication is established, the communication station 103 issues a query for collecting the approximate position information of the first node group 101 via the second node group 102. As described above, the approximate position information of the first node group 101 is sequentially transferred in a bucket relay manner, collected in the second node group 102, and transmitted to the communication station 103 by the light beam communication. The approximate position information of the first node group 101 is corrected by the position information correction unit 1034 in the communication station 103 and recorded in the sensor information recording unit 1033 as high-accuracy position information regarding the first node group 101. As a result, the number and position of the entire sensor network are grasped together with the position information and number of the second node group 102 transferred previously.
When the correction information is obtained from about three or four position reference points 107, the first node group 101 and the second node group 102 are all included in an area obtained by connecting the position reference points 107. It is desirable to do so.
At this time, the numbers of the first node group 101 and the second node group 102 grasped in the communication station 103 are automatically operated after being spread and constructed a sensor network. Is the number of valid ones.
Further, it is possible to start communication between the communication station 103 and the second node 102 without going through the communication process described in Step 2, but in this case, the communication station 103 is in a second stage at the initial stage. Since the position of the node 102 is not grasped at all, the position information of the communication station is transmitted from the communication station 103 on the light beam communication, and the beam is swept over the entire distribution area. The second node group 102 accidentally irradiates, and the second node itself calculates the transmission direction of the light beam transmitting means from its own approximate position information and the approximate position information of the communication station, and then based on this, It is necessary to operate the beam transmission direction adjusting means 1027, and it takes time to establish optical communication as compared with the above embodiment.

(Step 4)
The number and position of the sensor networks are grasped and the search mode is entered. The first node group 101 and the second node group 102 sense a target object corresponding to the function of the sensor means 1011 and 1021 provided therein. The communication station 103 issues a query for collecting information on a predetermined target such as magnetic sensing via the second node group 102. These pieces of information are sequentially transferred in a bucket relay manner as described above. The communication station 103 records this information in the sensor position information recording unit 1033 corresponding to the identification code ID, and further transferred from the second node group 102 by a light beam such as a laser beam in a data analysis unit (not shown). By analyzing the sensing information of the sensor, it is possible to know what object moves to what range and in what distribution. For example, it is possible to know how a vehicle is moving based on information on magnetic sensing, and on the basis of vibration sensing information, the vehicle or soldier is distinguished based on its sensing level, the soldier or soldier is distinguished based on sound, the biochemical weapons are identified. Based on the sensing information, the spread movement of the hazardous substance distribution can be known, and the next movement distribution can be predicted.
Note that data analysis and prediction may be performed in an integrated manner by a command and control vehicle 105 that directs a plurality of communication stations 103.

  According to the sensor network, even when a part of the sensors is damaged, the optimum network is automatically maintained by the ad hoc communication, so that the alternative network is immediately reconstructed.

  The wavelength of the laser beam for communication between the communication station 103 and the second node group 102 after the establishment of the sensor network is a wavelength that is less affected by atmospheric fluctuations, for example, a 700 to 900 μm band or an eye-safe wavelength. However, the present invention is not limited to this.

1 is an overview layout diagram of one embodiment of a system of the present invention. FIG. It is an internal block diagram of each part which comprises this invention system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 ... 1st node group, 102 ... 2nd node group, 103 ... Communication station, 104 ... UAV, 105 ... Command control vehicle, 106 ... Artificial satellite, 107 ... Position reference point, 108 ... Infantry, 109 ... Vehicle.

Claims (8)

  A plurality of first node groups including sensor means, self-position measuring means by GPS, and wireless transmitting / receiving means corresponding to all azimuth angles by radio waves, and wireless transmission / reception corresponding to all azimuth angles by GPS self-position measuring means and radio waves A plurality of second node groups comprising means, a light beam transmitting / receiving means using a narrow-angle light beam, and a light beam transmission direction adjusting means for adjusting a transmission direction, and the second node and the light beam transmitting / receiving means. And a communication station comprising a light beam transmission / reception means for communicating, a light beam transmission / reception direction adjustment means for adjusting the light beam transmission / reception direction, and a self-position measurement means by GPS, wherein the first node group And the second node group constructs a sensor network using ad hoc communication, and the second node group and the communication station transmit light beams. The light beam communication network is configured via the light beam transmission / reception means adjusted by the direction adjustment means and the light beam transmission / reception direction adjustment means, and the communication station includes each of the first node group and the second node group. A sensor network system characterized in that self-position information measured by a self-position measuring means of a node is obtained via a second node group.   The second node group distributes the self-position information measured by the self-position measuring means of at least one second node to the communication station by light diffusion using a wide-angle beam or radio waves from the second node. The sensor network system according to claim 1, further comprising: means.   3. The sensor network system according to claim 2, wherein when the self-location information is delivered from the second node to the communication station using the wide-angle communication means, it is delivered directly or via the relay means.   The relaying means is a node spreading means for moving in the air, comprising a relay wireless transmission / reception means, and a self-position provided for each of at least a second node of the scattered first node group and second node group The position information measured by the measuring means and received by the wide-angle communication means is received, and the received position information is further transmitted to a communication station using the relay wireless transmission / reception means. Sensor network system.   The communication station uses the second node group for the self-position information measured by the self-position measuring means of each node of the first node group and the second node group and the sensor information by the sensor means provided in each node. The sensor network system according to claim 1, wherein the sensor network system is obtained via the network.   The communication station is provided with position information correction means, and the position correction means corrects position information of at least the second node group and the communication station based on correction information calculated from the positioning information of the position reference point. The sensor network system according to any one of claims 1 to 5.   7. The position information correcting unit corrects an area surrounded by the plurality of position reference points based on positioning data at the plurality of reference points. The sensor network system described in 1. 8. The sensor network system according to claim 1, wherein a laser beam is used as light beam transmitting / receiving means using a narrow-angle light beam.

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