JP4968678B2 - Location information acquisition system - Google Patents

Description

  The present invention relates to a position information acquisition system for acquiring position information of a visitor using an RFID tag possessed by the visitor to a space such as a building.

  In recent years, as one of the major devices in the ubiquitous network society, active wireless IC tags (active RFID tags) with a relatively large communicable distance have been used not only for conventional logistics management but also for human location information. Being started. Typical examples include visitor services at the 2005 Expo 2005 Aichi Expo, demonstration experiments for safety management applications for elementary school students, etc., which are still expected to be used in various fields.

  Many tag readers of active tags have a function that can acquire the radio field intensity at the same time as the detection information. Therefore, by setting the effective radio field intensity range on the system side, the range can be reduced to a minimum of about 1 m. Yes, because it is possible to set the detection area according to various applications, when considering a system that acquires human location information in the facility, when radio waves are detected by a reader installed with the detection range adjusted In addition, a position acquisition method of “being in charge of the leader” can be considered.

For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2006-41834) discloses a position information acquisition method for acquiring position information using a marker laid at a specific place, in which a portable device is brought close to the marker. Transmitting a predetermined signal from the portable device to the marker in a state, and reading the identification information stored in the memory unit in response to receiving the predetermined signal from the portable device; Transmitting to the portable device; receiving the identification information from the marker; transmitting the identification information to a database server; obtaining the position information corresponding to the identification information by querying a database; Transmitting to the mobile device, and notifying the user of the location information received from the database server in a predetermined form. Location information acquisition method characterized the door is disclosed.
JP 2006-41834 A

However, in the system described in Patent Document 1, for example, an active RFID tag is used as a marker. However, the RFID tag has the following problems.
・ The problem of the influence of the human body The radio wave of 300-400MHz band used in many active type RFID tags has a great influence on the human body, so the acquisition rate of the radio wave depends on the direction the owner is facing and how Variation in detectable distance.
-The problem of the number of readers that can be read at the same time When the system is to have real-time capability, such as for detecting movement information of people walking, it is necessary to shorten the radio wave transmission interval of the RFID tag to some extent. However, due to the relationship between the tag ID data length and reader processing speed, the data that one reader receives simultaneously is limited (however, the transmission interval is not strictly constant and there are individual differences, so it will be detected after waiting for a while) To do). For this reason, it is necessary to take into account that the radio wave reception intensity decreases when a large number of people gather at the same time.
-Problem of variation in reader installation method When an RFID tag reader is installed in a facility, it is assumed that it will be installed in various places such as the back of the ceiling or under the OA floor due to an appearance problem. Since radio waves in the 300 to 400 MHz band are easily affected by metal, there is a problem that the sensitivity of each reader varies depending on the installation method and the arrangement of fixtures in the facility.

  The above problems are problems when reading RFID tags in a position information acquisition system using an active RFID tag, and these problems must be solved by an appropriate algorithm such as data interpolation on the system side. Such a proposal has not been made in the conventional system.

  In addition, a problem related to recording in the position information acquisition system can also be mentioned. In the position information acquisition system, it is desirable to store the acquired position information as a history. In this case, depending on the number of RFID tags, the number of tag readers, and the frequency of tag reading, the RFID in the position information acquisition system may be used. The tag reading log data becomes very large. When the read log data in the position information acquisition system becomes enormous, problems such as a slow processing speed of the system occur.

The present invention solves the above-mentioned problems, and the invention according to claim 1 acquires position information of a visitor by using an RFID tag possessed by the visitor to a space such as a building. In the system, RFID tags that are distributed to visitors to spaces such as buildings and wirelessly transmit signal radio waves related to unique tag ID information, and are installed for each of a plurality of areas in spaces such as buildings. A unique reader ID is attached, a tag reader that detects signal radio waves from the RFID tag, a radio wave intensity detection unit that detects detection intensity of the signal radio waves from the RFID tag, information on the RFID tag detected by the tag reader, etc. Based on the information stored in the storage unit and the information stored in the storage unit, position information related to the area where the RFID tag exists is displayed. And a priority table for storing the priority set according to the peripheral condition of the tag reader installation position for each tag reader, and the storage unit receives signal radio waves from the RFID tag by the tag reader. A log table that temporarily associates the detected reader ID of the tag reader, the tag ID information of the RFID tag, the detection intensity of the signal radio wave from the RFID tag, and the detection time of the signal radio wave each time it is detected, Once the RFID tag is detected by the tag reader, the main arithmetic unit, until the time elapses, information related to the count continuation time that the RFID tag is present in the area corresponding to the tag reader, Generate a log table with a count continuation time subscribed to the log table, and log table with the count continuation time On the basis of the priority table and to determine the data according to the area where there is an RFID tag, and to store the determined said data to said storage unit.

The invention according to claim 2 is distributed to visitors to a space such as a building in a location information acquisition system that acquires the location information of a visitor by means of an RFID tag possessed by a visitor to the space such as a building. An RFID tag that wirelessly transmits a signal radio wave related to unique tag ID information and a plurality of areas in a space such as a building, each with a unique reader ID, and a signal from the RFID tag A tag reader for detecting radio waves, a radio wave intensity detection unit for detecting the detection intensity of signal radio waves from the RFID tag, a storage unit for storing information on the RFID tag detected by the tag reader, and information stored in the storage unit Based on the main calculation unit for calculating the position information related to the area where the RFID tag exists and the tag reader for each tag reader. An installation condition coefficient table in which installation condition coefficients set according to the surrounding conditions of the installation position are stored, and the storage unit detects the signal radio wave from the RFID tag every time the tag reader detects the signal radio wave from the RFID tag. A log table associating a reader ID, tag ID information of the RFID tag, signal radio wave detection intensity from the RFID tag, and signal radio wave detection time is temporarily stored. When it is detected by the tag reader, the count continuation time when the information related to the count continuation time that the RFID tag is present in the area corresponding to the tag reader is added to the log table until the time elapses. A log table containing the count time and the installation condition coefficient table. There are, to confirm the data relating to the area where there is an RFID tag, and to store the determined said data to said storage unit.

  According to the position information acquisition system of the present invention, the concept of “priority”, “count continuation time” and the like are introduced, and an algorithm based on these is adopted. Data is deleted, and variation in the installation method of the RFID tag reader in the facility can be corrected to obtain position information close to position information by actual movement.

  Further, according to the position information acquisition system of the present invention, position information with low redundancy calculated based on the concepts of “priority”, “count continuation time” and the like is finally acquired. It is possible to avoid problems such as a decrease in the processing speed of the system due to the log data (read raw data).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an outline of a block configuration of a position information acquisition system according to an embodiment of the present invention. FIG. 2 is a conceptual diagram of installation of a tag reader in the position information acquisition system according to the embodiment of the present invention. The position information acquisition system is a system for acquiring position information for grasping the location of a building visitor using an RFID tag possessed by the building visitor, for example, by tag readers provided at various locations in the building. Although FIG. 1 illustrates the case where there are three tag readers, any number of tag readers can be provided.

  In FIG. 1, 10 is a main arithmetic unit, 20, 20 ', 20' "are tag readers, 25, 25 ', 25'" are radio wave intensity detection units, 30 is a storage unit, and 40 is a display unit. Although not shown in FIG. 1, it is assumed that the tag readers 20, 20 ', and 20' 'detect an active type RFID tag possessed by a building visitor or the like. Each tag reader is given an ID of the reader so as to be distinguished. Here, it is assumed that the reader ID of the tag reader 20 is “001”, the reader ID of the tag reader 20 ′ is “002”, and the reader ID of the tag reader 20 ′ ′ is “003”. These tag readers 20, 20 ′, 20 ′ ′ are installed at intervals for each predetermined area, and receive radio waves from RFID tags possessed by a building entrant or the like in each area. FIG. 2 shows an image of the detection area of the tag reader with the reader ID “001”, the detection area of the tag reader with the reader ID “002”, and the detection area of the tag reader with the reader ID “003”.

  The main processing unit 10 includes a central processing unit such as a CPU, a non-rewritable storage element such as a ROM, a rewritable storage element such as a RAM, a large capacity storage device such as an HDD, an input device such as a keyboard and a pointing device, a monitor, A general-purpose information processing mechanism including an external output device such as a printing device and a peripheral device such as a network connection device. For example, a system such as a general personal computer can be used. The main arithmetic unit 10 performs processing and control for the position information acquisition system according to the present invention by cooperating with each configuration. A program for controlling and processing such a position information acquisition system is written in a non-rewritable storage element such as a ROM or a mass storage device such as an HDD. By executing such a program in the main arithmetic unit 10, the function of the position information acquisition system of the present invention can be realized. The display unit such as a monitor in the main processing unit 10 is provided with an interface screen for displaying in which area the building visitor holding the RFID tag is present.

  An RFID tag having a unique (unique) ID is distributed to a visitor or a visitor in a building where a position information acquisition system is installed. The RFID tag is assigned a unique (unique) ID number and has a built-in transmitter capable of transmitting the ID number. The RFID tag is configured to transmit its own ID information at a frequency of about once every 3 seconds, for example.

  The tag readers 20, 20 ′, 20 ′ ′ read ID numbers transmitted from such transmitters of RFID tags, and the radio wave intensity detection units 25, 25 ′ in the tag readers 20, 20 ′, 20 ′ ′. , 25 ′ ′ detect the intensity of the signal radio wave from the transmitter of the RFID tag. In the position information acquisition system of the present invention, which area (area 001, area 002 in FIG. 2) the entrant holding the RFID tag depends on the intensity of the radio wave detected by the radio wave intensity detection units 25, 25 ′, 25 ′ ′. , Area 003, etc.).

  The tag readers 20, 20 ′, 20 ′ ′ transmit “ID information” and “detection intensity” from the RFID tag to the main calculation unit 10. The main calculation unit 10 adds the information related to the “reader ID” of the detected tag reader and the information related to the “detection time” by a clocking unit (not shown) to the data of “ID information” and “detection intensity”, Collective information including “reader ID”, “tag ID information”, “detection intensity”, and “detection time” is acquired and used as a log.

  Such a log is temporarily stored in the storage unit 30 as a “log table”. FIG. 3 is a diagram showing a data structure of a log table of the position information acquisition system according to the embodiment of the present invention.

  Further, the storage unit 30 holds a reader ID of the tag readers 20, 20 ′, 20 ′ ′ and a database of respective priorities. FIG. 4 is a diagram showing data on the relationship between the reader ID of the tag reader held by the storage unit 30 and its priority.

  Here, the “priority” in the present invention will be described. The tag readers 20, 20 ′, 20 ′ ′ may acquire the same radio wave from the RFID tag simultaneously with a plurality of tag readers. In such a case, when detected by a plurality of tag readers at the same time, it can be determined by comparing the detected radio wave intensity which area is to be determined, that is, which tag reader is near.

  However, as described above, the actual detection intensity does not necessarily depend on the distance between the RFID tag and the tag reader depending on the installation conditions of the tag reader and the surrounding conditions of the installation position.

  Therefore, in the present invention, by setting a parameter called “priority” for each tag reader, processing for complementing information related to the detection intensity is performed. For example, if there is a problem that an important conference room where you want to acquire location information has a problem that the detected radio wave is lower than the surrounding tag reader due to the installation conditions of the tag reader, the priority of the tag reader installed in the conference room By setting it higher than the reader, position information can be prevented from being confused.

  In the example of FIG. 4, the priority of the tag reader having the reader ID 002 is set higher than that of the reader IDs 001 and 003, such as “10”. In the present invention, a tag reader with a high priority uses an algorithm that preferentially handles even if the detected radio wave intensity is small.

  In the algorithm of the position information acquisition system of the present invention, the concept of “count continuation time” is introduced in addition to the concept of “priority”.

  This “count continuation time” is a time at which once an RFID tag is detected by a tag reader, it is assumed that the RFID tag exists in an area corresponding to the tag reader until that time elapses. Information that cannot be received by the tag reader is complemented by assuming that the user is in that place until such a count duration has elapsed. By introducing the concept of count duration, for example, when an RFID tag that transmits at intervals of 3 seconds and the count duration is 30 seconds, if it can be detected at least once every 10 times, it can be confirmed that the place is located It can be done.

  In the position information acquisition system of the present invention, the concept of “priority” and “count continuation time” as described above is introduced, and an algorithm based on these is adopted. Therefore, it is possible to acquire position information close to position information by actual movement.

  FIG. 5 is a log table in which the data of the log table of FIG. 3 is organized for each tag reader and the count continuation time is taken into account.

  Next, an algorithm for determining position information when log data is acquired from a plurality of tag readers in the position information acquisition system of the present invention will be described. FIG. 6 is a diagram showing a flowchart of the position information acquisition process of the position information acquisition system according to the embodiment of the present invention. This flow of position information acquisition processing is executed at a sufficiently short time interval as compared to the change in movement of the RFID tag holder. In the flowchart, what is shown as “data” corresponds to the data A to I in FIG.

  In the flowchart of FIG. 6, when the position information acquisition process is started in step S100, the process proceeds to step S101, where it is determined whether or not a predetermined time has elapsed.

  When the determination result in step S101 is NO, step S101 is looped until a predetermined time has elapsed. When the determination result of step S101 is YES, the process proceeds to step S102.

  In step S <b> 102, it is determined whether there is data in which the count duration continues in the log table.

  When the result in step S102 is YES, the process proceeds to step S103. If the result in step S102 is NO, there is no data to be acquired as position information, so the process proceeds to step S111, and the position information acquisition process ends.

  In step S103, all data for which the count duration continues in the log table are extracted. In the next step S104, it is determined whether there are a plurality of data extracted in step S103.

  When the determination result of step S104 is YES, the process proceeds to step S106, and when the determination result of step S104 is NO, the process proceeds to step S105.

  When the determination result in step S104 is NO, there is only one target data. Therefore, in step S105, the tag reader that generated the data is acquired as position information. In the next step S111, position information acquisition is performed. The process ends.

  In step S106, the priority of the tag reader acquired for each of a plurality of data is referred to by the priority table of FIG.

  In step S107, it is determined whether there is data generated by the tag reader with the highest priority among a plurality of data. When the determination result of step S107 is YES, the process proceeds to step S108, and when the determination result of step S107 is NO, the process proceeds to step S109.

  In step S108, the tag reader that generated the data (the highest priority) is acquired as position information. In the next step S111, the position information acquisition process is terminated.

  In step S109, the detected intensity of the tag reader obtained for each of the plurality of data is compared. In step S110, the tag reader that generated the data with the maximum detected intensity is acquired as position information. In the next step S111, the position information acquisition process is terminated.

  Next, an example of obtaining position information by the position information obtaining process of the present invention as described above will be described. FIG. 7 is a diagram showing position information acquired from the data in the log table of FIG. FIG. 8 is a diagram showing a data configuration finally stored in the storage unit of the position information acquisition system according to the embodiment of the present invention.

  The graph in the upper half of FIG. 7 is a plot of the log data of FIG. On the other hand, the lower half of FIG. 7 shows the position information obtained by the position information acquisition process of the present invention. In the lower half graph of FIG. 7, the horizontal axis indicates time as in the upper half graph, and the vertical axis indicates the reader ID (or an area corresponding to the reader ID) acquired as position information. In the lower half graph of FIG. 7, the count duration is set to 15 seconds.

  FIG. 8 shows a graph of the lower half of FIG. 7 in a table. Thus, the log data shown in FIG. 3 becomes compact data as shown in FIG. 8 by the algorithm of the position information acquisition system of the present invention. In the present invention, since the data shown in FIG. 8 is configured to be stored in the storage unit 30, problems such as a decrease in the processing speed of the system due to a large amount of log data (read raw data) can be avoided. It becomes. That is, the position information acquisition system of the present invention finally determines and acquires position information with low redundancy calculated based on the concepts of “priority” and “count continuation time”. It becomes possible to avoid the problem like.

  Next, another embodiment of the present invention will be described. In the previous embodiment, by introducing the concept of “priority” for each tag reader, the algorithm is configured in consideration of the installation conditions for each tag reader, the radio wave reception environment from the RFID tag, etc. Then, the concept of “installation condition coefficient” is introduced and reflected in the position information acquisition algorithm.

  In the present embodiment, a low “installation condition coefficient” is assigned to a tag reader that receives radio waves from an RFID tag, and a high “installation condition coefficient” is assigned to a tag reader that does not receive radio waves from an RFID tag. Then, the position information acquisition is acquired by comparing the product of the detection intensity detected by the radio wave intensity detectors 25, 25 ', 25' 'and the installation condition coefficient. FIG. 9 is a diagram showing data on the relationship between the reader ID of the tag reader and its installation condition coefficient.

  Also in this embodiment, the case where the log data of FIG. 3 is acquired by the tag reader will be described as an example. FIG. 10 is a log table in which the data of the log table of FIG. 3 is organized for each tag reader and (detection intensity) × (installation condition coefficient) and count continuation time are taken into account.

  Next, an algorithm for determining position information when log data is acquired from a plurality of tag readers in a position information acquisition system according to another embodiment of the present invention will be described. FIG. 11 is a diagram showing a flowchart of the position information acquisition process of the position information acquisition system according to another embodiment of the present invention. This flow of position information acquisition processing is executed at a sufficiently short time interval as compared to the change in movement of the RFID tag holder. In the flowchart, what is shown as “data” corresponds to the data A to I in FIG.

  In the flowchart of FIG. 6, when the position information acquisition process is started in step S200, the process proceeds to step S201, where it is determined whether or not a predetermined time has elapsed.

  When the determination result of step S201 is NO, step S201 is looped until a predetermined time elapses. When the determination result of step S201 is YES, the process proceeds to step S202.

  In step S <b> 202, it is determined whether there is data in which the count duration continues in the log table.

  When the result in step S202 is YES, the process proceeds to step S203. When the result in step S202 is NO, there is no data to be acquired as position information, so the process proceeds to step S208, and the position information acquisition process ends.

  In step S203, all data for which the count duration has continued are extracted from the log table. In the next step S204, it is determined whether there are a plurality of data extracted in step S203.

  When the determination result of step S204 is YES, the process proceeds to step S206, and when the determination result of step S204 is NO, the process proceeds to step S205.

  When the determination result in step S204 is NO, there is only one target data. Therefore, in step S205, the tag reader that generated the data is acquired as position information, and in the next step S208, position information acquisition is performed. The process ends.

  In step S206, (detection intensity) × (installation condition coefficient) of each tag reader obtained for each of a plurality of data is referred to by the table of FIG.

  In step S207, the tag reader having the highest (detection intensity) × (installation condition coefficient) value among the tag readers that have generated a plurality of data is acquired as position information. In the next step S208, the position information acquisition process is terminated.

  Next, an example of obtaining position information by the position information obtaining process of the present invention as described above will be described. FIG. 12 is a diagram showing position information acquired from the data in the log table of FIG. FIG. 13 is a diagram showing a data configuration finally stored in the storage unit of the position information acquisition system according to another embodiment of the present invention.

  The graph in the upper half of FIG. 12 is a plot of (time) vs. (detection intensity) × (installation condition coefficient) with the installation condition coefficient added to the log data of FIG. On the other hand, the lower half of the graph in FIG. 12 shows the position information obtained by the position information acquisition process of the present embodiment. In the lower half graph of FIG. 12, the horizontal axis indicates the time as in the upper half graph, and the vertical axis indicates the reader ID (or an area corresponding to the reader ID) acquired as position information. In the lower half graph of FIG. 12, the count duration is set to 15 seconds.

  FIG. 13 shows a graph of the lower half of FIG. 12 in the form of a table. Thus, the log data shown in FIG. 3 becomes compact data as shown in FIG. 13 by the algorithm of the position information acquisition system of the present invention. In the present embodiment, since the data shown in FIG. 13 is configured to be stored in the storage unit 30, problems such as a decrease in the processing speed of the system due to a large amount of log data (read raw data) can be avoided. It becomes possible. That is, the position information acquisition system according to another embodiment of the present invention finally determines and acquires position information with low redundancy calculated based on the concepts of “installation condition coefficient” and “count continuation time”. Therefore, the above problem can be avoided.

  Although various embodiments have been described above, embodiments configured by appropriately combining the configurations of the respective embodiments also fall within the scope of the present invention.

It is a figure which shows the outline | summary of the block configuration of the positional infomation acquisition system which concerns on embodiment of this invention. It is the installation conceptual diagram of the tag reader of the positional information acquisition system which concerns on embodiment of this invention. It is a figure which shows the data structure of the log table of the positional infomation acquisition system which concerns on embodiment of this invention. It is a figure which shows the data of the relationship between reader ID of a tag reader, and its priority. It is a figure which shows the log table containing count continuation time of the positional information acquisition system which concerns on embodiment of this invention. It is a figure which shows the flowchart of the positional information acquisition process of the positional information acquisition system which concerns on embodiment of this invention. It is a figure which shows the positional information etc. which are acquired by the data of the log table of FIG. It is a figure which shows the data structure finally preserve | saved at the memory | storage part of the positional information acquisition system which concerns on embodiment of this invention. It is a figure which shows the data of the relationship between reader ID of a tag reader, and its installation condition coefficient. It is a figure which shows the log table containing count continuation time of the positional information acquisition system which concerns on other embodiment of this invention. It is a figure which shows the flowchart of the positional information acquisition process of the positional information acquisition system which concerns on other embodiment of this invention. It is a figure which shows the positional information etc. which are acquired by the data of the log table of FIG. It is a figure which shows the data structure finally preserve | saved at the memory | storage part of the positional information acquisition system which concerns on other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Main operation part, 20, 20 ', 20' '... Tag reader, 25, 25', 25 '' ... Radio wave intensity detection part, 30 ... Storage part, 40 ... Display part

Claims (2)

In a location information acquisition system that acquires location information of a visitor with an RFID tag possessed by a visitor to a space such as a building,
An RFID tag that is distributed to visitors to a space such as a building and wirelessly transmits signal radio waves related to unique tag ID information;
A tag reader that is installed for each of a plurality of areas in a space such as a building, has a unique reader ID, and detects a signal radio wave from an RFID tag;
A radio wave intensity detection unit for detecting the detection intensity of the signal radio wave from the RFID tag;
A storage unit for storing information related to the RFID tag detected by the tag reader;
Based on the information stored in the storage unit, a main calculation unit that calculates position information related to the area where the RFID tag exists;
A priority table for storing the priority set according to the peripheral conditions of the tag reader installation position for each tag reader;
The storage unit detects the reader ID of the detected tag reader, the tag ID information of the RFID tag, the detected intensity of the signal radio wave from the RFID tag, and the detection time of the signal radio wave each time the tag reader detects the signal radio wave from the RFID tag. And temporarily store a log table that associates
Once the RFID tag is detected by the tag reader, the main processing unit obtains information related to the count continuation time that the RFID tag is considered to exist in the area corresponding to the tag reader until the time elapses. , and generates a count continuation time cored log table subscribed to the log table, on the basis of the priority table and the count continues time entering log table, and determine the data according to the area where there is an RFID tag, was determined the A position information acquisition system , wherein data is stored in the storage unit . In a location information acquisition system that acquires location information of a visitor with an RFID tag possessed by a visitor to a space such as a building,
An RFID tag that is distributed to visitors to a space such as a building and wirelessly transmits signal radio waves related to unique tag ID information;
A tag reader that is installed for each of a plurality of areas in a space such as a building, has a unique reader ID, and detects a signal radio wave from an RFID tag;
A radio wave intensity detection unit for detecting the detection intensity of the signal radio wave from the RFID tag;
A storage unit for storing information related to the RFID tag detected by the tag reader;
Based on the information stored in the storage unit, a main calculation unit that calculates position information related to the area where the RFID tag exists;
For each tag reader, an installation condition coefficient table storing an installation condition coefficient set according to the peripheral condition of the tag reader installation position is provided,
The storage unit detects the reader ID of the detected tag reader, the tag ID information of the RFID tag, the detected intensity of the signal radio wave from the RFID tag, and the detection time of the signal radio wave each time the tag reader detects the signal radio wave from the RFID tag. And temporarily store a log table that associates
Once the RFID tag is detected by the tag reader, the main processing unit obtains information related to the count continuation time that the RFID tag is considered to exist in the area corresponding to the tag reader until the time elapses. , Generating a log table including the count continuation time subscribed to the log table, and determining data related to the area where the RFID tag exists based on the log table including the count continuation time and the installation condition coefficient table . The position information acquisition system, wherein the data is stored in the storage unit .

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