JP2007017375A - Position detection tag, position detection device, position detection method and position detection system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a position detection system capable of measuring a position and an azimuth inexpensively and accurately by using a radio IC tag. <P>SOLUTION: A position detection tag 11 is constituted of a plurality of radio IC tags 21-24 having each different polarization direction. A tag number is transmitted in response by a radio IC tag corresponding to linear polarization of a signal transmitted from a position detection device 12 among the radio IC tags 21-24. An interrogator 32 of the position detection device 12 retrieves data stored in a conversion table by the tang number of the responding radio IC tag, reads out position information (the position and the direction) corresponding to the responding radio IC tag, and specifies the position and the direction of a user. A linearly polarized signal transmitted from the position detection device 12 has a longer arrival distance compared with a circularly polarized signal, to thereby enable separation of an antenna 31 of the position detection device 12 from the position detection tag 11. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a position detection tag, a position detection device, a position detection method, and a position detection system.

  Conventionally, a position detection device that detects a position by GPS (Global Positioning System) is known. However, this position detection device is expensive, and because GPS radio waves are shielded by the building, the position cannot be detected indoors or in an area where the building is dense.

  Thus, various position detection systems using non-contact wireless IC tags have been proposed. For example, in Patent Document 1, a base station that is provided for each area gate, receives information on a wireless IC tag passing through the gate, and detects the moving direction of the wireless IC tag; and There is disclosed a position detection system including a center that receives information on a received wireless IC tag and information indicating a moving direction of the IC tag. The center of the position detection system creates position information indicating the area where the wireless IC tag exists based on the received information on the wireless IC tag and information indicating the moving direction of the wireless IC tag. Form a database of information. Therefore, by accessing this database, the current position of the designated wireless IC tag can be known.

Further, in Patent Document 2, a plurality of non-contact type electronic tags are provided at a work place, and a read sensor unit that reacts according to the operation of the worker and data obtained by the read sensor unit are used. A system for automatically recording a worker's action, which automatically records a work content and a work time accompanying the movement of the worker's hand, is disclosed.
Japanese Patent Laying-Open No. 2005-064725 JP 2005-032082 A

  Incidentally, in recent years, a large amount of information has been brought to users via a computer network. Further, ubiquitous computing that provides information required by a user at a necessary place when needed is desired, and it is required to automatically detect position information such as a user's location and direction.

  However, in the system of Patent Document 1, although the area where the IC tag exists can be specified, the position of the IC tag in the area cannot be specified. Moreover, in the system of Patent Document 1, it is possible to specify the position of the IC tag in the area by arranging a plurality of base stations in the area. However, since the distance between the IC tag and the base station is defined by the radio waves transmitted from the IC tag and the base station, a large number of base stations must be arranged in order to accurately determine the position of the IC tag. In other words, there is a problem that enormous equipment costs are required. Furthermore, even if many base stations are arranged, it cannot be detected which direction the user who owns the IC tag is facing.

  Moreover, in the system of patent document 2, the position of the user who owns the reader apparatus can be detected without incurring equipment costs by arranging a plurality of electronic tags at the work place. However, in this system, as in the system of Patent Document 1, it is impossible to detect which direction the user is facing.

  The present invention has been made to solve the above problems, and its purpose is to provide a position detection tag and position detection capable of accurately measuring the position and orientation at low cost using a wireless IC tag. An apparatus, a position detection method, and a position detection system are provided.

  In order to achieve the above object, the invention according to claim 1 is arranged on a moving surface on which a moving body on which the moving body moves, and a position detecting device provided with an antenna that is arranged on the moving body and transmits a linearly polarized signal. A position detection system including a plurality of position detection tags, wherein an angle between a polarization direction of the antenna included in the position detection tag and a polarization direction of the antenna included in the position detection device is relative to each other. Angle changing means for changing the position of the wireless IC tag to the position of the wireless IC tag, and the position of the wireless IC tag stored in association with each other. Transmitting and searching the storage means by the tag number of the wireless IC tag responding to the interrogation signal to read the arrangement position associated with the tag number and the relative angle of the polarization of the two antennas And interrogator that detects the orientation of the moving object, further comprising a a gist.

  According to a second aspect of the present invention, in the position detection system according to the first aspect, the antenna of the position detection device is arranged so as to send a linearly polarized signal along a direction corresponding to the direction of the moving body. The angle changing means is provided in the position detection tag, and is arranged by a plurality of wireless IC tags that are arranged so that the polarization directions of the antennas are different from each other and transmit specific tag numbers through the antennas, respectively. The position detection device is configured to transmit a linearly polarized signal, and a storage unit that stores the tag numbers of the plurality of wireless IC tags, the arrangement positions, and the direction corresponding to the direction of the antenna in association with each other. An antenna for transmitting a query signal through the antenna, reading a tag number from the plurality of wireless IC tags, searching the storage means by the acquired tag number The location information associated with the No. and summarized in that with a, and interrogator for reading from the storage means.

  According to a third aspect of the present invention, in the position detection system according to the second aspect, the interrogator stores the position information for each of tag numbers received from a plurality of wireless IC tags responding to the interrogation signal. A gist is provided with a filter unit that reads out from the means and identifies the position and direction of the moving body based on a plurality of pieces of position information read out by the interrogator.

  According to a fourth aspect of the present invention, in the position detection system according to the first aspect, the position detection tag is a wireless IC tag that is arranged in a predetermined direction and transmits a specific tag number via the antenna. The angle changing means is a polarization rotating means for rotating a polarization direction of a signal transmitted from an antenna of the position detecting device, and the position detecting device includes a tag number and an arrangement position of the wireless IC tag, and A storage means that is stored in association with an arrangement direction, and transmits a question signal via the antenna, reads a tag number from the wireless IC tag, searches the storage means by the acquired tag number, and searches the tag number An interrogator that reads position information associated with the storage means from the storage means, a polarization direction of the signal, and position information of the mobile IC from the position information of the wireless IC tag. And summarized in that it includes a data portion.

  The invention according to claim 5 is the position detection system according to claim 3 or 4, further comprising storage means in which the detected position and direction of the moving body are stored in time series, and the filter unit includes The gist is to determine the direction of the moving body based on the position and direction stored in the storage means.

  According to a sixth aspect of the present invention, there is provided a position detection tag having a plurality of wireless IC tags that are arranged so that the polarization directions of the antennas are different from each other and that respectively transmit specific tag numbers through the antenna. A position detection device disposed on a moving body that moves along a moving surface, wherein tag numbers, arrangement positions, and directions corresponding to directions of the antennas are stored in association with each other. Storage means, an antenna for transmitting a linearly polarized signal, an interrogation signal is transmitted via the antenna, a tag number is read from the plurality of wireless IC tags, and the storage means is controlled by the acquired tag number. The gist is provided with an interrogator that retrieves position information associated with the tag number from the storage means.

  According to the seventh aspect of the present invention, a position detection tag having one wireless IC tag for transmitting a specific tag number via the antenna is disposed along the polarization direction of the antenna. A position detection device disposed on a moving body that moves along a moving surface, an antenna for transmitting a linearly polarized signal, and a polarization that rotates the polarization direction of the signal transmitted from the antenna A rotating means, a storage means in which the tag number of the wireless IC tag and the arrangement position and orientation are stored in association with each other, a question signal is transmitted via the antenna, and the tag number is read from the wireless IC tag, From the interrogator that searches the storage means by the acquired tag number and reads the position information associated with the tag number from the storage means, the polarization direction of the signal, and the position information of the wireless IC tag. A filter unit for detecting the position and direction of the moving body, and summarized in that with a.

  According to an eighth aspect of the present invention, there is provided a position detection tag having a plurality of wireless IC tags that are arranged so that the polarization directions of the antennas are different from each other and that respectively transmit specific tag numbers through the antenna. A position detecting method for detecting a position of the moving body in a position detecting apparatus disposed on the moving body that moves on the moving surface, wherein the position detecting apparatus includes tag numbers and arrangement positions of the plurality of wireless IC tags. And a storage means associated with a direction corresponding to the direction of the antenna, and an antenna for transmitting a linearly polarized signal, transmitting a query signal via the antenna, The tag number is read out from the wireless IC tag, the storage means is searched by the acquired tag number, the position information associated with the tag number is read out from the storage means, and the position information is Ri is summarized in that to detect the position of the movable body.

  According to the ninth aspect of the invention, a position detection tag having one wireless IC tag for transmitting a specific tag number via the antenna is arranged along the polarization direction of the antenna. A position detection method for detecting the position and direction of a moving body in a position detecting apparatus disposed on a moving body that moves along a moving surface, wherein the position detecting apparatus transmits a linearly polarized signal. Antennas, polarization rotation means for rotating the polarization direction of a signal transmitted from the antenna, and storage means for storing the tag number of the wireless IC tag in association with the arrangement position and arrangement direction. A query signal is transmitted via the antenna, a tag number is read from the wireless IC tag, the storage means is searched by the acquired tag number, and the position information associated with the tag number is recorded. Reading from the means, and summarized in that to determine the position and direction of the moving body from the rotation angle of the antenna and the position information of the wireless IC tag.

  The invention according to claim 10 is a position detection tag arranged on a moving surface on which the moving body moves, and has an antenna for receiving an interrogation signal from a position detection device arranged on the moving body. The gist of the invention is that the antenna includes a plurality of wireless IC tags which are arranged so that the polarization directions of the antennas are different from each other and transmit a tag number in response to the interrogation signal.

  Therefore, according to the first aspect of the present invention, the angle changing means relatively sets an angle between the polarization direction of the antenna included in the position detection tag and the polarization direction of the antenna included in the position detection device. change. The position and angle of the wireless IC tag responding to the signal transmitted from the interrogator of the position detection device via the antenna, the polarization direction of the linearly polarized signal transmitted from the position detection device, and the deviation of the antenna of the wireless IC tag. The position and direction of the moving body can be detected based on the relative angle with the wave direction. Further, since the linearly polarized signal transmitted from the position detecting device has a longer reach than the circularly polarized signal, a question / response is performed without bringing the position detecting device close to the position detecting tag.

  Therefore, according to the second, sixth, and eighth aspects of the present invention, the wireless IC tag corresponding to the linearly polarized wave of the signal transmitted by the position detecting device among the plurality of wireless IC tags constituting the position detecting tag. In response, send the tag number. The data stored in the storage means is searched by the tag number of the responding wireless IC tag, and the position and direction corresponding to the responding wireless IC tag correspond to the position and direction of the moving body, that is, the position of the moving body. And the direction can be detected. Further, since the linearly polarized signal transmitted from the position detecting device has a longer reach than the circularly polarized signal, a question / response is performed without bringing the position detecting device close to the position detecting tag.

  According to the third aspect of the present invention, when a plurality of wireless IC tags respond to a signal transmitted toward the position detection tag, movement is performed from a plurality of position information read by the tag numbers of the plurality of wireless IC tags. The position and direction of the body is detected. For this reason, the position and direction of the moving body can be detected with an accuracy narrower than the arrangement interval of the position detection tags.

  According to the fourth, seventh, and ninth aspects of the present invention, the signal is transmitted from the antenna of the position detecting device to the one wireless IC tag provided in the position detecting tag by the polarization rotating means as the angle changing means. By rotating the polarization direction of the signal, the relative angle between the polarization direction of the wireless IC tag and the polarization direction of the signal can be easily changed. Then, the position and direction of the moving body can be detected from the polarization direction of the signal and the position information of the wireless IC tag.

  According to the fifth aspect of the present invention, the direction determined by the wireless IC tag that responds to a linearly polarized signal is in principle between 0 and 180 degrees, and between 180 and 360 degrees, it is 0. It is the same value as between ˜180 degrees. That is, since 90 degrees and 270 degrees return the same value, they cannot be distinguished. However, since the moving direction of the moving body, that is, the direction of the moving body can be estimated from the position information of the moving body so far, the direction of the moving body at that point can be detected.

  According to the invention described in claim 10, since the plurality of wireless IC tags have different polarization directions of the antennas, the wireless IC tag corresponding to the linearly polarized signal responds. The direction of the position detection device that transmits a linearly polarized signal can be detected depending on the direction.

  As described above, according to the present invention, a position detection tag, a position detection device, a position detection method, and a position detection system capable of accurately measuring a position and a direction at low cost using a wireless IC tag are provided. Can be provided.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1A is a schematic block diagram of the position detection system.

The position detection system 10 includes a position detection tag 11 and a position detection device 12.
The position detection tag 11 is a wireless IC tag group including a plurality (four in this embodiment) of wireless IC tags 21 to 24. The first wireless IC tag 21 includes an antenna 21a and a response circuit (IC chip) 21b. The first wireless IC tag 21 is a passive IC tag, and the response circuit 21b operates by receiving power supply from the position detection device 12, and transmits a transmission signal including a preset tag number 21c to the antenna 21a. To send through. The tag number 21c is a unique number assigned to identify each wireless IC tag. The antenna 21a is a linearly polarized wave type antenna. Since the second to fourth wireless IC tags 22 to 24 are configured in the same manner as the first wireless IC tag 21, the drawings and description are omitted.

  As shown in FIG. 1B, the first to fourth wireless IC tags 21 to 24 are arranged so that the polarization directions of the antennas 21 a are different, and are fixed to and integrated with the fixing plate 25. In the present embodiment, the first to fourth wireless IC tags 21 to 24 have their centers O1 to O4 equidistant from the center O of the position detection tag 11, that is, the circumference of the center O (see FIG. Are arranged on a circle indicated by a one-dot chain line).

  The first to fourth wireless IC tags 21 to 24 are formed in a rod shape, and the longitudinal direction is the polarization direction of the antenna 21a. That is, the antenna 21a receives a radio wave of a component in the longitudinal direction among the received radio waves. The first to fourth wireless IC tags 21 to 24 are arranged so that the polarization direction of the antenna 21a differs by 45 degrees. An antenna 31 of the position detection device 12 to be described later transmits a linearly polarized signal (for example, a signal in the polarization direction indicated by a two-dot chain line in the figure). Accordingly, the first to fourth wireless IC tags 21 to 24 constitute angle changing means for changing the relative angle between the polarization direction of the signal and the polarization direction of the antenna of each.

  The response circuit 21b operates by the power generated by the received radio wave at the antenna 21a, and the generated power is determined by the polarization direction of the antenna 21a and the polarization direction of the received radio wave. For example, when the polarization direction of the received radio wave is the direction indicated by the two-dot chain line in FIG. 1B, the polarization direction of the radio wave (question signal 41) is the polarization direction of the antenna 21a of the first wireless IC tag 21. And is orthogonal to the polarization direction of the antenna of the third wireless IC tag 23. Accordingly, the first wireless IC tag 21 transmits the tag number in response to the radio wave (question signal 41), and the third wireless IC tag 23 hardly responds to the radio wave (question signal 41). In the second and fourth wireless IC tags 22 and 24, the polarization direction of the radio wave (question signal 41) is deviated by 45 degrees with respect to the polarization direction of the antenna. Accordingly, the second and fourth wireless IC tags 22 and 24 operate based on the component in the polarization direction of the antenna in the radio wave (question signal 41). Since the magnitude of the polarization component received by the second and fourth radio IC tags 22 and 24 is smaller than the magnitude of the polarization component received by the first radio IC tag 21, the second and fourth radio ICs The number of times the tags 22 and 24 respond per unit time (the number of times the tag number is transmitted) is smaller than the number of times that the first wireless IC tag 21 responds per unit time.

  A plurality of the position detection tags 11 are arranged on a moving surface such as a floor surface or the ground through which a moving body (for example, a person) whose position is to be detected passes. For example, as shown in FIG. 2A, the plurality of position detection tags 11 are arranged in a matrix with a predetermined interval (horizontal interval X2, vertical interval Y2) in a predetermined region (X1, Y1). An area in which a plurality of position detection tags 11 are arranged is called a detection area. That is, the detection area is an area for detecting the position and direction of the user who owns the position detection device 12. The position detection device 12 may be attached to a moving body such as a robot and the position and direction of the moving body may be detected.

As illustrated in FIG. 2B, the position detection device 12 includes a main body 12 a attached to the waist of the user 51 and a display unit 12 b possessed by the user 51.
As shown in FIG. 1A, the position detection device 12 includes an antenna 31, an interrogator 32, a conversion table 33 as storage means, a filter unit 34 as filter means, an action table 35 as storage means, and display means. The display unit 12b and the communication unit 36 are provided. In the present embodiment, the main body 12a shown in FIG. 2B includes an antenna 31, an interrogator 32, a conversion table 33, a behavior table 35, a filter unit 34, and a communication unit 36.

  The antenna 31 is an antenna whose plane of polarization is linearly polarized wave, and transmits radio waves of linearly polarized wave. The main body 12a shown in FIG. 2B is attached so that the polarization direction of the signal to be transmitted coincides with the horizontal direction of the user.

  The interrogator 32 transmits an interrogation signal for inquiring the tag number of the wireless IC tag via the antenna 31. The interrogator 32 acquires the position of the wireless IC tag in response to the inquiry signal and the direction (direction) of the wireless IC tag based on the tag number included in the signal received from the wireless IC tag via the antenna 31. To do. The conversion table 33 is used for acquiring the position and the like.

  As shown in FIG. 3A, the conversion table 33 includes a tag number (ID) of each wireless IC tag, a position (coordinates) where the wireless IC tag is arranged, and a wireless tag for all the position detection tags 11. It is a table in which an IC tag arrangement direction (tag direction) is associated. The arrangement position is an absolute position (latitude and longitude), a relative position with respect to the reference position, a number for specifying the arranged matrix, and the like. In the present embodiment, four wireless IC tags 21 to 24 are arranged in one position detection tag 11, and the positions of the wireless IC tags 21 to 24 included in this one position detection tag 11 are The center position O of the detection tag 11 is set. The arrangement position may be a reference position of each of the wireless IC tags 21 to 24 (centers O1 to O4 of the wireless IC tags, points on the side, arbitrary points).

  The arrangement direction (azimuth vector) is unique information (for example, character information of “1” to “4”) indicating an angle formed by an axis such as a ground axis and the polarization direction of each wireless IC tag. In the present embodiment, the direction of the first wireless IC tag 21 is “1”, the direction of the second wireless IC tag 22 is “3”, the direction of the third wireless IC tag 23 is “3”, The direction of the 4 wireless IC tag 24 is “4”.

  The interrogator 32 searches the conversion table 33 using the tag number (reception tag number) received from the position detection tag 11, the tag number that matches the reception tag number, and the position and arrangement direction associated with the tag number. Are read from the conversion table 33. As a result, the interrogator 32 converts the tag number of the wireless IC tag responding to the interrogation signal transmitted via the antenna 31 into the position and direction. This position and direction correspond to the position of the position detection device 12, that is, the position of the user who owns the position detection device 12. As described above, a plurality of position detection tags 11 are arranged in the detection area. Therefore, the position of the user who owns the position detection device 12 can be measured according to the arrangement interval of the position detection tags 11 by using the arranged position detection tags 11 in this detection region.

  Among the plurality of wireless IC tags 21 to 24 constituting the position detection tag 11, the wireless IC tag corresponding to the polarization of the inquiry signal transmitted from the position detection device 12 responds to the inquiry signal with a tag number. Send. Therefore, the direction of the user can be measured by the wireless IC tag that responds to the linearly polarized interrogation signal.

  Note that four wireless IC tags 21 to 24 are arranged in one position detection tag 11. Therefore, a plurality of wireless IC tags may respond to an interrogation signal transmitted from the interrogator 32 via the antenna 31. For example, as shown in FIG. 1B, the first wireless IC tag 21, the second wireless IC tag 22, and the fourth wireless IC tag 24 respond in accordance with the polarization direction of the interrogation signal 41. The interrogator 32 converts the tag numbers of all the wireless IC tags that respond by the conversion table 33 into position information (position and direction (orientation vector)). Then, the interrogator 32 outputs the position information to the filter unit 34.

  The filter unit 34 detects the current position of the user based on the position information input from the interrogator 32. When a plurality of wireless IC tags respond to the inquiry signal, the filter unit 34 detects the current position and direction of the user based on position information obtained from the tag number of each wireless IC tag. For example, when wireless IC tags of a plurality of position detection tags 11 respond, the center positions of the plurality of position detection tags 11 are obtained from the tag numbers of the wireless IC tags. The filter unit 34 uses the position of the center of gravity of the coordinates of the position detection tag 11 including the responding wireless IC tag as the current position of the user. Thereby, even if a user exists between the several tags 11 for position detection, the position of the user can be measured. That is, the position can be measured more finely than the arrangement interval of the position detection tags 11.

  The filter unit 34 detects the user's direction (direction) based on the position information input from the interrogator 32. An action table 35 is used for detecting the direction. As shown in FIG. 3B, the behavior table 35 is a table in which time, tag number (ID), position (coordinates), and direction are associated as information.

  The time is the time when the filter unit 34 detects the position and direction of the user according to the movement of the user, and the tag number (ID) is used for the filter unit 34 to detect the position and direction at that time. This is the tag number (ID) of the wireless IC tag. The position (coordinates) and direction (orientation) are the user position and user orientation (orientation) detected by the filter unit 34 at that time. That is, the action table 35 stores the position and orientation detected according to the movement of the user in time series.

  Incidentally, the first wireless IC tag 21 shown in FIG. 1B responds to the interrogation signal 41 in the polarization direction shown in the drawing. The position detection device 12 is attached so that the polarization direction of the interrogation signal 41 matches the left-right direction of the user. However, only the polarization direction of the interrogation signal 41 cannot determine whether the user is facing the upper right direction or the user is facing the lower left direction. For this reason, the filter unit 34 detects the current user direction based on the information stored in the behavior table 35, that is, the position information of the user detected in the past. For example, a polarization direction interrogation signal 41 shown in FIG. 1B is transmitted to the current position detection tag 11, and the past specific point is the position detection tag on the upper right in FIG. 1B. In this case, the filter unit 34 determines that the user is facing the lower left, and when the past specific point is the lower left position detection tag in FIG. 1B, the filter unit 34 the user is facing the upper right. Judge. As described above, the filter unit 34 can detect the orientation of the user based on the information stored in the behavior table 35. Then, the filter unit 34 adds the detected position information (position and direction), the tag number (ID) used for detecting the position information, and the detected time to the action table 35.

  The display unit 12b displays the position and direction detected by the filter unit 34. In addition, since the display part 12b alert | reports the position and the direction which were detected with respect to the user, you may make it alert | report not only by a display part but with an audio | voice.

  The communication unit 36 transmits the position and angle detected by the filter unit 34 to the external device. As a transmission method, a wireless LAN, a mobile phone network, or the like is applicable. By transmitting the position and angle to the external device, for example, it is possible to provide route guidance and information corresponding to the detected position and direction (for example, description of exhibits such as paintings).

  FIG. 5 shows the result of examining the response of the wireless IC tags 21 to 24 to the change in the direction of the linearly polarized wave of the interrogation signal in the position detection tag 11. In this measurement, an inquiry signal is transmitted every predetermined time, and the response frequency of the wireless IC tag responding to the transmission signal is measured. When the polarization direction of the interrogation signal is rotated, the wireless IC tag that responds changes according to the rotation angle. The peak of the number of responses in each wireless IC tag appears with an interval of about 180 degrees. From this measurement, it was confirmed that the wireless IC tag in a direction parallel to the antenna 31 of the position detection device 12 responds according to the rotation of the polarization. Note that the difference in the number of responses of each wireless IC tag is considered to be due to variations in electrical characteristics of the wireless IC tag here.

  4A and 4B are explanatory views showing a position measurement test in the detection region shown in FIG. In the position measurement test, the user who owns the position detection device 12 moves along the circle shown in FIG. 4A, and the position measurement result (coordinate value) at the time of movement is shown in FIG. 4B. Since the user moves along the circle, the polarization direction of the interrogation signal 41 is the radial direction of the circle of the movement path as shown in FIG. 4A and 4B, position detection tags 11 are arranged at intersections of straight lines drawn in the horizontal and vertical directions in the figure. The horizontal and vertical intervals (X2, Y2) of the plurality of position detection tags 11 are set to 250 mm, for example. As shown in FIG. 4B, points close to the user's movement path are measured. In FIG. 4B, the average error of the measurement point with respect to the radius of the user's moving path (circle) was about 75 mm.

As described above, according to the present embodiment, the following effects can be obtained.
(1) The position detection tag 11 is composed of a plurality of wireless IC tags 21 to 24 having different polarization directions. Among these wireless IC tags 21 to 24, the wireless IC tag corresponding to the linear polarization of the signal transmitted by the position detection device 12 responds and transmits the tag number. The interrogator 32 of the position detection device 12 searches the data stored in the conversion table 33 based on the tag number of the responding wireless IC tag, and reads the position information (position and direction) corresponding to the responding wireless IC tag. . This position and direction correspond to the position and direction of the moving body. Therefore, it is possible to detect the position of the user and the orientation of the user in each position detection tag 11.

  (2) Further, since the linearly polarized signal transmitted from the position detection device 12 has a longer reach than the circularly polarized signal, the antenna 31 of the position detection device 12 and the position detection tag 11 are separated from each other. Can do. For this reason, it is not necessary to bring the antenna 31 close to the position detection tag 11, for example, without using a cane or the like provided with the antenna 31 at the tip in order to bring the antenna 31 close to the position detection tag 11. The position and direction of the user carrying the position detection device 12 can be detected with high accuracy.

  (3) When a plurality of wireless IC tags respond to a signal transmitted toward the position detection tag 11, the interrogator 32 has read from the conversion table 33 by the tag numbers of the plurality of wireless IC tags. A center position of a plurality of pieces of position information (position and direction) is obtained. This center position is taken as the user's position. For this reason, a user's position and direction can be detected with an accuracy narrower than the arrangement interval of the position detection tags 11.

  (4) The direction determined by the wireless IC tag responding to the linearly polarized signal is in principle between 0 and 180 degrees, and between 180 and 360 degrees is the same value as between 0 and 180 degrees. It becomes. That is, since 90 degrees and 270 degrees return the same value, they cannot be distinguished. However, the position information of the user so far is stored in the action table 35, and by referring to the data of the action table 35, the filter unit 34 estimates the moving direction of the user, that is, the direction of the user. Therefore, the direction of the user at that point can be detected.

(Second embodiment)
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings.
In addition, about the same member as 1st embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted.

FIG. 6A is a schematic block diagram of the position detection system of the present embodiment.
The position detection system 60 includes a position detection tag 61 and a position detection device 62.

  The position detection tags 61 include one wireless IC tag 21 and are arranged in a matrix as in the first embodiment. The wireless IC tag 21 is a passive IC tag composed of an antenna 21a and a response circuit (IC chip) 21b. The response circuit 21b operates by receiving power supply from the position detection device 62 and is preset. A transmission signal including the tag number 21c is transmitted via the antenna 21a.

  The position detection device 62 includes an antenna 31, an interrogator 32, an antenna driving unit 63 as an angle changing unit and a polarization rotation unit, a conversion table 33 as a storage unit, a filter unit 64 as a filter unit, and an action table as a storage unit. 35, a display unit 12b as a display means, and a communication unit 36 are provided.

  The antenna 31 is an antenna whose plane of polarization is linearly polarized wave, and transmits radio waves of linearly polarized wave. The antenna drive unit 63 is a drive unit that rotationally drives the antenna 31 using, for example, a stepping motor as a drive source. When the antenna drive unit 63 rotationally drives the antenna 31, the polarization direction of the signal transmitted from the antenna 31 is increased. Is mechanically rotated.

  Note that the polarization direction of the signal transmitted from the antenna may be electrically rotated. For example, as illustrated in FIG. 7, the antenna 71 is a linearly polarized patch antenna, and the antenna driving unit switches feeding points P <b> 1 to P <b> 4 that supply a transmission signal input from the interrogator 32 to the antenna 71. The linearly polarized patch antenna transmits a signal in the polarization direction corresponding to the position of the feeding point. Therefore, by sequentially switching the feeding points P1 to P4, the polarization direction of the transmitted signal can be rotated.

  The interrogator 32 transmits an interrogation signal for inquiring the tag number of the wireless IC tag via the antenna 31. The interrogator 32 acquires the position of the wireless IC tag in response to the inquiry signal and the direction (direction) of the wireless IC tag based on the tag number included in the signal received from the wireless IC tag via the antenna 31. To do. The conversion table 33 is used for acquiring the position and the like.

  The filter unit 64 detects the current position of the user based on the position information of the wireless IC tag input from the interrogator 32 and the angle of the signal polarization rotated by the antenna driving unit 63. For example, as described in the first embodiment, the response frequency of the wireless IC tag changes according to the polarization direction of the signal transmitted from the interrogator 32 through the antenna 31. Therefore, the direction of the user can be detected from the polarization direction of the signal when the response frequency of the wireless IC tag is large. For example, when the polarization direction of the signal when the response frequency of the wireless IC tag is large is 0 degree (the angle at which the polarization direction of the signal is the left-right direction of the user), the wireless IC tag 21 shown in FIG. On the other hand, it is detected that the user is facing the upper side of the drawing or the lower side of the drawing. In addition, the filter unit 64 specifies the detected user orientation based on the information stored in the behavior table 35.

As described above, according to this embodiment, in addition to the effects of the first embodiment, the following effects can be obtained.
(5) Since the polarization direction of the signal transmitted from the antenna 31 of the position detection device 62 is rotated, one wireless IC tag 21 may be mounted on the position detection tag 61. Therefore, the outer shape of the position detection tag 61 can be reduced, and the cost of the position detection tag 61 can be reduced.

  (6) Since the polarization direction of the signal transmitted from the antenna 31 of the position detection device 62 is rotated, the angle step in the polarization direction can be arbitrarily set. Therefore, the direction of the moving body can be detected more finely by rotating the polarization direction of the signal in finer steps.

In addition, you may implement each said embodiment in the following aspects.
In the first embodiment, the position detection tag 11 is composed of the four wireless IC tags 21 to 24. However, the position detection tag is composed of two, three, five or more wireless IC tags. It may be.

In the above embodiments, the position detection tags 11 and 61 are arranged in a matrix, but they may be arranged at arbitrary positions.
In each of the above embodiments, the position detection device 12 is mounted on the user's waist, but the installation position is changed within a range where radio wave intensity capable of supplying power to the wireless IC tag can be secured. Well. For example, it is possible to change the mounting position according to the use situation, such as mounting in shoes.

In each of the above embodiments, the passive wireless IC tags 21 to 24 are used, but an active wireless IC tag may be used.
In the above embodiment, the frequency of response of the wireless IC tag increases as the angle formed by the polarization of the interrogation signal and the polarization direction of the antenna 21a is closer to 0 (zero). Therefore, when a plurality of wireless IC tags respond, the filter unit 34 may set the number of responses of each wireless IC tag as a weight for the position and direction, and may use the weighted position and direction average value as the position and direction of the moving body. .

  In the above embodiment, the filter unit 34 may detect the direction of the moving body by combining the direction vectors stored in the conversion table 33 corresponding to the plurality of wireless IC tags that respond to the question signal. .

  In each of the above embodiments, the direction of the moving body (user) may be determined based on the direction of the wireless IC tags 21 to 24 without using the action table 35. For example, when the position rotates without changing the position, the wireless IC tag that mainly responds to the question signal 41 (the number of responses increases) changes. For this reason, the orientation of the moving body can be detected by converting the tag number of the wireless IC tag that responds to the direction of the wireless IC tag using the conversion table 33.

The technical ideas that can be grasped from each of the above forms are described below.
(B) The interrogator reads position information from the storage unit for each of the tag numbers received from the plurality of wireless IC tags responding to the question signal, and the plurality of position information read by the interrogator. The position detection apparatus according to claim 6, further comprising a filter unit that detects a position and a direction of the moving body based on the position.

  (B) storage means in which the detected position and direction of the moving body are stored in time series, and the filter unit determines the direction of the moving body based on the position and direction stored in the storage means; The position detection device according to claim 7, wherein the position detection device detects the position.

  (C) Position information is read out from the storage means for each of the tag numbers received from the plurality of wireless IC tags responding to the interrogation signal, and the position and direction of the moving body based on the plurality of position information read out The position detection method according to claim 8, wherein the position is detected.

  (D) comprising storage means for storing the detected position and direction of the moving body in time series, and detecting the direction of the moving body based on the position and direction stored in the storage means. The position detection method according to (9) or claim 9 above.

(A) is a schematic block diagram of the position detection system of 1st embodiment, (b) is a top view of the tag for position detection of 1st embodiment. (A) and (b) are explanatory drawings of a position detection area. (A) is explanatory drawing of a conversion table, (b) is explanatory drawing of action data. (A) is the schematic explaining a position detection test, (b) is a characteristic view which shows a position detection result. The characteristic view which shows the frequency | count of reaction of the radio | wireless tag which comprises the tag for position detection with respect to the polarization direction of an antenna. (A) is a schematic block diagram of the position detection system of 2nd embodiment, (b) is a top view of the tag for position detection of 2nd embodiment. An explanatory view of an antenna.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11, 61 ... Position detection tag, 21-24 ... Wireless IC tag, 21a ... Antenna, 21b ... Response circuit, 21c ... Tag number, 12, 62 ... Position detection device, 31, 71 ... Antenna, 32 ... Interrogator, 33 ... Conversion table, 34, 64 ... Filter unit, 35 ... Action data, 63 ... Antenna drive unit as angle changing means and polarization rotating means.

Claims (10)

A position detection system comprising a position detection device including an antenna disposed on a moving body and transmitting a linearly polarized signal, and a plurality of position detection tags disposed on a moving surface on which the moving body moves. There,
An angle changing means for relatively changing the angle between the polarization direction of the antenna of the position detection tag and the polarization direction of the antenna of the position detection device;
The position detecting device transmits a question signal via the antenna and responds to the question signal, storing means in which the tag number of the wireless IC tag and the arrangement position of the wireless IC tag are stored in association with each other. An interrogator that searches the storage means by the tag number of the wireless IC tag to read the arrangement position associated with the tag number and detects the orientation of the moving body by the relative angle of the polarization of the two antennas; A position detection system comprising: The antenna of the position detection device is disposed so as to send a linearly polarized signal along a direction corresponding to the direction of the moving body,
The angle changing means is provided in the position detection tag, and is configured by a plurality of wireless IC tags that are arranged so that the polarization directions of the antennas are different from each other and respectively transmit a specific tag number via the antenna. ,
The position detection device includes:
Storage means for storing tag numbers and arrangement positions of the plurality of wireless IC tags and directions corresponding to directions of the antennas;
An antenna for transmitting a linearly polarized signal;
An interrogation signal is transmitted via the antenna, a tag number is read from the plurality of wireless IC tags, the storage unit is searched by the acquired tag number, and position information associated with the tag number is read from the storage unit Interrogator,
The position detection system according to claim 1, further comprising: The interrogator reads position information from the storage means for each of the tag numbers received from a plurality of wireless IC tags that respond to the question signal,
The position detection system according to claim 2, further comprising a filter unit that identifies a position and a direction of the moving body based on a plurality of pieces of position information read by the interrogator. The position detection tag includes one wireless IC tag that is arranged in a predetermined direction and transmits a specific tag number via the antenna,
The angle changing means is a polarization rotating means for rotating the polarization direction of a signal transmitted from the antenna of the position detecting device,
The position detection device includes:
Storage means for storing a tag number of the wireless IC tag, an arrangement position and an arrangement direction in association with each other;
An interrogator that transmits an interrogation signal via the antenna, reads a tag number from the wireless IC tag, searches the storage means by the acquired tag number, and reads position information associated with the tag number from the storage means When,
A filter unit for detecting the position and direction of the moving body from the polarization direction of the signal and the position information of the wireless IC tag;
The position detection system according to claim 1, further comprising: Comprising storage means for storing the detected position and direction of the moving body in time series;
5. The position detection system according to claim 3, wherein the filter unit specifies a direction of the moving body based on a position and a direction stored in the storage unit. Movement that moves along a moving surface on which position detection tags having a plurality of wireless IC tags that are arranged so that the directions of polarization of antennas are different from each other and that transmit specific tag numbers via the antennas are arranged A position detection device disposed on the body,
Storage means for storing tag numbers and arrangement positions of the plurality of wireless IC tags and directions corresponding to directions of the antennas;
An antenna for transmitting a linearly polarized signal;
An interrogation signal is transmitted via the antenna, a tag number is read from the plurality of wireless IC tags, the storage unit is searched by the acquired tag number, and position information associated with the tag number is read from the storage unit Interrogator,
A position detection device comprising: A moving body that moves along a moving surface on which a position detection tag having one wireless IC tag in which a polarization direction of an antenna is arranged along a predetermined direction and a specific tag number is transmitted through the antenna is arranged. A position detecting device disposed in
An antenna for transmitting a linearly polarized signal;
Polarization rotation means for rotating the polarization direction of the signal transmitted from the antenna;
Storage means for storing a tag number of the wireless IC tag, an arrangement position and an arrangement direction in association with each other;
An interrogator that transmits an interrogation signal via the antenna, reads a tag number from the wireless IC tag, searches the storage means by the acquired tag number, and reads position information associated with the tag number from the storage means When,
A filter unit for detecting the position and direction of the moving body from the polarization direction of the signal and the position information of the wireless IC tag;
A position detection device comprising: A moving body that moves on a moving surface on which a position detection tag having a plurality of wireless IC tags that are arranged so that directions of polarization of antennas are different from each other and that transmit specific tag numbers via the antennas is arranged. A position detection method for detecting a position of the moving body in a disposed position detection device,
The position detection device includes:
Storage means for storing tag numbers and arrangement positions of the plurality of wireless IC tags and directions corresponding to directions of the antennas;
An antenna for transmitting a linearly polarized signal,
The interrogation signal is transmitted via the antenna, the tag number is read from the plurality of wireless IC tags, the storage unit is searched based on the acquired tag number, and the position information associated with the tag number is read from the storage unit. A position detection method comprising detecting the position of the moving body based on the position information. A moving body that moves along a moving surface on which a position detection tag having one wireless IC tag in which a polarization direction of an antenna is arranged along a predetermined direction and a specific tag number is transmitted through the antenna is arranged. A position detection method for detecting the position and direction of the moving body in the position detection device disposed in
The position detection device includes:
An antenna for transmitting a linearly polarized signal;
Polarization rotation means for rotating the polarization direction of the signal transmitted from the antenna;
Storage means for storing the tag number of the wireless IC tag, the arrangement position and the arrangement direction in association with each other, and
The interrogation signal is transmitted through the antenna, the tag number is read from the wireless IC tag, the storage unit is searched by the acquired tag number, and the position information associated with the tag number is read from the storage unit, A position detection method comprising: determining a position and a direction of the moving body from a polarization direction of a signal and position information of the wireless IC tag. A position detection tag arranged on a moving surface on which the moving body moves,
A plurality of antennas that receive an interrogation signal from a position detection device arranged in the mobile body, are arranged such that the polarization directions of the antennas are different from each other, and transmit a tag number in response to the interrogation signal A position detection tag comprising the wireless IC tag.

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