JP2005164361A - Position detection by means of intelligent gps and of ic tag intercommunication, and processing by gis - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a position detection system being a basic technology for various systems required to perform high-accuracy position detection. <P>SOLUTION: This position detection system includes at least one GPS receiver, and an IC tag as a position detecting object. At least one GPS receiver further comprises a measurement means for performing distance measurement based on signal arrival time by transmitting/receiving signals to/from the IC tag. The position of the IC tag is determined on the basis of absolute position information calculated through GPS positioning in at least one GPS receiver, and distance information between at least one GPS receiver and the IC tag, the distance information being measured by the measurement means in at least one GPS receiver. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a position detection system using a GPS and an IC tag.

  The GPS receiver is widely used for detecting the position of a moving body such as a car navigation device as being capable of measuring an absolute position at an observation point. In recent years, GPS receivers have also started to be used as means for monitoring slope displacement from the viewpoint of disaster prevention. The following Patent Document 1 describes the use of GPS positioning for slope displacement detection. According to Patent Document 1, the GPS measuring means installed on the slope outputs time series measurement data, and it is determined whether or not the slope has been deformed based on the time series measurement data.

JP 2003-214849 A

  From the aspect of disaster prevention / crisis management, it is considered to be necessary to install a system for detecting the deformation of various structures such as roads, tunnels and buildings. By installing a system for detecting deformations in these civil engineering structures, etc., there is a possibility that a part of the pier, a part of the concrete wall in the tunnel, etc. may be detected quickly. This is because it can be expected to lead to disaster prevention.

  However, according to the prior art, in order to realize the above-described deformation detection system for civil engineering structures, a number of GPS receivers corresponding to the required detection accuracy are provided on the surface to be measured of the structure. Must be placed. This means that in consideration of the cost and size of the GPS receiver, it is practically impossible to realize such a deformation detection system for civil engineering structures.

  The present invention has been made in view of such circumstances. That is, an object of the present invention is advantageous in terms of accuracy and cost, and is a position detection system that can be a fundamental technology for various systems that require highly accurate position detection, such as civil engineering structure deformation detection systems. Is to provide.

  In order to solve the above-described problem, according to one aspect of the present invention, a position detection system including at least one GPS receiver and an IC tag as a position detection target is provided. The at least one GPS receiver further includes a measuring unit that performs distance measurement based on the arrival time of the signal by transmitting and receiving the signal to and from the IC tag. Based on absolute position information calculated by GPS positioning in at least one GPS receiver and distance information between at least one GPS receiver and an IC tag measured by measuring means in at least one GPS receiver Thus, the position of the IC tag is determined (claim 1).

  In the above configuration, at least one GPS receiver may include a plurality of GPS receivers, and each of the plurality of GPS receivers may further include a communication unit for mutually communicating information with each other. In this case, the absolute position information obtained by each of the plurality of GPS receivers and the distance information between the IC tags are collected in one of the plurality of GPS receivers via the communication means, and In the single GPS receiver, the position of the IC tag can be determined (claim 2).

Alternatively, at least one GPS receiver includes a plurality of GPS receivers, and each of the plurality of GPS receivers has a first communication means for mutually communicating information with each other,
At least one of the plurality of GPS receivers may include a second communication unit for communicating with the center system. In this case, the absolute position information obtained by each of the plurality of GPS receivers and the distance information between the IC tags are communicated with the center system of the plurality of GPS receivers via the first communication means. After being collected by a possible GPS receiver, it is transmitted to the center system, and the position of the IC tag can be determined in the center system.

  When at least one GPS receiver includes three or more GPS receivers, the position of the IC tag can be calculated as a three-dimensional position.

  When there are a plurality of IC tags as position detection targets, a distance between at least one GPS receiver is obtained for each of the plurality of IC tags, and a position is determined for each of the plurality of IC tags. (Claim 5).

In order to solve the above problem, according to another aspect of the present invention,
Obtain absolute position information by GPS positioning in at least one GPS receiver having a function of transmitting and receiving signals to and from the IC tag,
Measure the distance information between at least one GPS receiver and the IC tag by the arrival time of the signal,
A position detection method is provided, wherein the position of the IC tag is determined based on the absolute position information and the distance information.

  According to the configuration of the present invention, the position of the IC tag is determined based on the absolute position information of the GPS receiver obtained by GPS positioning and the distance information obtained by the arrival time of the signal between the GPS receiver and the IC tag. It can be determined with high accuracy. By using the determined time-series position information, it is possible to monitor the minute displacement of the IC tag. For example, it is possible to detect a minute deformation of a civil engineering structure by installing an IC tag on a position detection target such as a civil engineering structure. Since the IC tag itself does not need to receive a GPS signal, the IC tag can be arranged inside a tunnel where the GPS signal is shielded.

  FIG. 1 is a diagram showing a basic concept of a position detection system 1 of the present invention. As shown in FIG. 1, the position detection system 1 includes a plurality of GPS units 11 to 14 and an IC tag 21. As will be described in detail later, the GPS units 11 to 14 have a function of transmitting and receiving radio waves for distance measurement with the tag 21 and a function of communicating with each other between GPS receiving units in addition to the function of performing GPS positioning. have.

  The principle that the position of the IC tag 21 is detected by the position detection system 1 of FIG. 1 will be described. Each GPS unit 11-14 measures the arrival time of the radio wave from the IC tag 21 by transmitting / receiving radio waves to / from the IC tag 21. Each of the GPSs 11 to 14 can be configured so that distance measurement end notifications are mutually exchanged so that the distances to the IC tag 21 are sequentially measured in the order of, for example, GPS 11, GPS 12, GPS 13, and GPS 14. . Or each GPS11-14 can also be set as the structure which measures the distance from IC tag 21 at once by receiving the electromagnetic wave from IC tag 21 at a predetermined timing all at once.

  It is assumed that the arrival times of radio waves from the IC tag 21 measured by the respective GPS units 11 to 14 are t1 to t4. Each GPS unit 11-14 calculates | requires the distance from IC tag 21 from the arrival time of this electromagnetic wave. In addition, each GPS unit 11-14 has acquired its absolute position by GPS positioning.

  Next, the three GPS units 12 to 14 of the four GPS units transmit the distance from the IC tag 21 and their absolute positions obtained by GPS positioning to the GPS unit 11. As described above, since the distances from the four reference points whose absolute positions are known to the IC tag 21 are obtained and the information is collected in the GPS unit 11, the GPS unit 11 calculates the three-dimensional position of the IC tag 21. be able to. Note that the three-dimensional position of the IC tag 21 can be calculated if the distances from the three reference points are obtained. Therefore, the position detection system 1 in FIG. If the GPS unit and the IC tag are arranged on the same plane, the position of the IC tag can be obtained even if there are two GPS units.

  FIG. 2 is a block diagram showing the configuration of the GPS units 11-14. Since the block configurations of the GPS units 11 to 14 are the same, the configuration of the GPS unit 11 is shown as a representative in FIG. As shown in FIG. 2, the GPS unit 11 includes a GPS module 31 that performs GPS positioning, a system controller 32 that has the same function as a personal computer, a communication interface 33 that performs communication between GPS units, and an IC tag 210. The tag receiver 34 for transmitting and receiving signals to and from is provided.

  The GPS unit 31 may be configured to achieve positioning accuracy on the order of centimeters, for example, by RTK-DGPS (real-time kinematic-differential GPS). In this case, the correction information necessary for performing RTK-DGPS may be configured such that the system controller 32 is provided from the outside via a communication interface device (not shown). The GPS module 31 may have a configuration generally known as a GPS receiver that performs single positioning.

  The system controller 32 has functions equivalent to those of a personal computer. That is, the system controller 32 includes a storage device including a low power consumption type CPU, ROM, RAM, flash memory, and the like. The ROM includes a function for measuring the distance to the IC tag 21 including the operating system, a function for communicating with each GPS unit, and a function for calculating the position of the IC tag based on information provided from each GPS unit. Each program for realizing the above is stored.

  The communication interface 33 is an interface for performing wireless connection with other GPS units. The communication interface 303 may be an interface device for wireless LAN. In this case, each GPS unit can be connected based on the TCP / IP protocol. The GPS unit 11 uses a low power consumption element, and is configured to be energized only when each of the portions 31, 33, and 34 is necessary, so that operation by a battery is possible.

  FIG. 3 is a block diagram showing the configuration of the IC tag 21. The IC tag 21 is an IC tag that can read and write information without a battery, and includes an antenna 41, a control unit 42, a power supply unit 43, and a non-volatile memory 44 such as a flash memory. The power supply unit 43 generates a power supply for operating the IC tag 21 by converting a high-frequency signal received from the tag receiver 34 in the GPS unit via the antenna 41 into a DC voltage by a rectifier circuit.

  The control unit 42 has a signal modulation and demodulation function, and a function of analyzing a signal from the tag receiver 34 and performing a requested operation. For example, when a signal from the tag receiver 34 instructs writing to the memory 44, information is written to the memory 44. On the other hand, when the signal from the tag receiver 34 instructs reading of information, the information from the memory 44 is read and transmitted from the antenna 41 to the tag receiver 34.

  In addition, in the communication between the tag receiver 34 and the IC tag 21, signals in various bands can be used. However, considering that the IC tag 21 may be embedded in the concrete, concrete or the like may penetrate to some extent. It is preferable to use a UWB (Ultra Wide Band) signal. Alternatively, instead of using UWB, for example, communication using a 2.45 GHz band signal may be performed.

  The above is a description of the basic concept of the position detection system 1 and the internal blocks of the GPS unit and IC tag. Since the IC tag 21 can be realized as a small IC chip, for example, by embedding the IC tag 21 in the concrete in the civil engineering structure, a minute displacement of the concrete portion including the IC tag 21 is also detected. It is possible.

  Next, two examples of application of the basic concept of position detection by the position detection system 1 are shown.

  FIG. 4 shows a deformation detection system 70 to which the position detection system 1 is applied. The deformation detection system 70 is a system that detects a change in the slope of a civil engineering structure and enables maintenance / crisis management. In FIG. 4, a plurality of IC tags 330 (corresponding to the IC tag 21 in FIG. 1) are embedded in the slope. On the slope, three GPS units 301 to 303 (corresponding to GPS units 11 to 13 in FIG. 1) are installed. The deformation detection system 70 detects the deformation of the slope by detecting the position of the IC tag embedded in the soil.

  In the deformation detection system 70, there are a plurality of IC tags. Therefore, each GPS unit 301 to 303 needs to know which IC tag it is communicating with. In this example, it is assumed that the IC tag stores an identification ID in the internal memory (44), and each GPS unit identifies each IC tag by this identification ID.

  FIG. 5 is a flowchart showing the deformation detection process performed by each of the GPS units 301 to 303. As shown in the flowchart in FIG. 5, each GPS unit 301 to 303 scans IC tags existing around itself at a predetermined timing such as when the power is turned on, and initializes position information for each IC tag. Set. That is, first, each GPS unit performs a scanning operation of transmitting an inquiry signal that does not specify a partner and receiving a response signal from the IC tag (S11). At this time, the IC tag that has received the inquiry signal from the GPS unit sends back a response signal including its own identification information. Note that each IC tag returns a response according to a predetermined transmission procedure for avoiding a collision, for example, by detecting a collision of signals so that response signals from the respective IC tags do not collide.

  Next, each GPS unit performs transmission / reception specifying the other party to each IC tag 330 that has responded, thereby measuring the distance of each IC tag 330 with reference to each GPS unit (S12). ). The distance between each GPS unit and each IC tag obtained in this way is collected in one GPS unit 301 together with the absolute position information of each GPS unit obtained by GPS positioning. Thereby, the GPS unit 301 can calculate the three-dimensional position of each IC tag 330 (S14). Next, deformation detection is performed by comparing the position of each IC tag obtained in step S14 with the position obtained by past measurement (S15). Note that the processing shown in FIG. 5 is performed periodically, for example, once every 10 minutes.

  From the above description, it can be understood that the deformation detection system 70 can detect the deformation of the slope with high accuracy.

  Next, another application example of the position detection system 1 of FIG. 1 will be described. FIG. 6 shows a pedestrian position detection system 200 as an application of the position determination system 1 of FIG. As shown in FIG. 6, in the pedestrian position detection system 200, GPS units 211 to 213 (corresponding to the GPS units 11 to 13 in FIG. 1) are installed on the roadside utility pole, and the pedestrian carries the IC tag 221. ing.

  Similar to the basic concept described with reference to FIG. 1, each GPS unit 211 to 213 obtains a distance from the pedestrian by transmitting and receiving signals to and from the IC tag 221 carried by the pedestrian. Each obtained distance and the absolute position of the GPS unit itself obtained by GPS positioning in each GPS unit are collected in the GPS unit 211. Then, the GPS unit 211 calculates the absolute position of the pedestrian. The calculated pedestrian position may be provided to the pedestrian himself via a communication device (not shown) or may be transmitted to a management center (not shown).

  The embodiment of the present invention described above can be variously modified without departing from the scope of the present invention. For example, in the position detection system 1 shown in FIG. 1, the IC tag 21 has been described as having the memory 44. However, when the IC tag 21 is used only for measuring the distance from the GPS unit, Since the IC tag 21 only needs to transmit and receive signals, it is not always necessary to include the memory 44.

  It is understood that the basic concept of the position detection system based on communication between the GPS unit and the IC tag shown in FIG. 1 can be applied not only to the maintenance and crisis management of structures but also to various scenes that require highly accurate position detection. it can. Since it is not necessary to perform GPS positioning for the position detection target, the position detection system of the present invention can be used when the position detection target is in an environment where GPS radio waves do not reach, such as the inner wall of a tunnel. The point is noted.

  The deformation detection information (position information) obtained by the deformation detection system 70 as shown in FIG. 4 can be processed by a GIS (geographic information system). That is, if a system comprising the deformation detection system 70 and the GIS is configured, the deformation detection information is received and processed on the GIS side, so that the location where the deformation has occurred and the state of the deformation are displayed together with the map information. It can be displayed on the display screen.

FIG. 1 is a diagram showing a basic concept of a position detection system 1 of the present invention. FIG. 2 is a block diagram showing the configuration of the GPS units 11-14. FIG. 3 is a block diagram showing the configuration of the IC tag 21. FIG. 4 shows a deformation detection system 70 to which the position detection system 1 is applied. FIG. 5 is a flowchart showing the deformation detection process performed by each of the GPS units 301 to 303. FIG. 6 shows a pedestrian position detection system 200 as an application of the position determination system 1 of FIG.

Explanation of symbols

1 Position detection system 11-14 GPS unit 21 IC tag

Claims (6)

At least one GPS receiver;
A position detection system comprising an IC tag as a position detection target,
The at least one GPS receiver further includes a measurement unit that performs distance measurement according to the arrival time of the signal by transmitting and receiving a signal to and from the IC tag,
Absolute position information calculated by GPS positioning in the at least one GPS receiver, and measured by the measuring means in the at least one GPS receiver, between the at least one GPS receiver and the IC tag. And determining the position of the IC tag based on distance information. The at least one GPS receiver comprises a plurality of GPS receivers;
Each of the plurality of GPS receivers further includes communication means for mutually communicating information with each other,
Absolute position information obtained by each of the plurality of GPS receivers and distance information between the IC tags are collected in one of the plurality of GPS receivers via the communication means, The position detection system according to claim 1, wherein the position of the IC tag is determined by the one GPS receiver. The at least one GPS receiver comprises a plurality of GPS receivers;
Each of the plurality of GPS receivers further includes a first communication means for mutually communicating information with each other,
At least one of the plurality of GPS receivers has a second communication means for communicating with a center system;
The absolute position information and the distance information between the IC tags respectively obtained by the plurality of GPS receivers are the center system of the plurality of GPS receivers via the first communication means. 2. The position detection system according to claim 1, wherein the IC tag is transmitted to the center system after being collected by a GPS receiver capable of communicating with the receiver, and the position of the IC tag is determined in the center system.   The said at least 1 GPS receiver consists of 3 or more GPS receivers, The position of the said IC tag is calculated as a three-dimensional position, The Claim 1 characterized by the above-mentioned. Position detection system. There are a plurality of IC tags as the position detection targets,
The distance between the at least one GPS receiver is obtained for each of the plurality of IC tags, and the position is determined for each of the plurality of IC tags. The position detection method according to any one of the above. Obtain absolute position information by GPS positioning in at least one GPS receiver having a function of transmitting and receiving signals to and from the IC tag,
Measuring distance information between the at least one GPS receiver and the IC tag according to the arrival time of the signal;
Determining the position of the IC tag based on the absolute position information and the distance information;
A position detection method characterized by.

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