JP2011149774A - Position detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a position detector capable of facilitating a correlation between radio tags and position information and reducing burden at the time of introduction and maintenance thereof. <P>SOLUTION: The position detector includes two or more radio tags which are placed along a moving route and memorize numbers sequentially assigned depending on a change amount of a disposed position from a reference position as tag IDs; a storage means which memorizes table information linking a tag ID of a radio tag located at the head of each section, a distance of the radio tag from the reference position, and a total number of radio tags placed at each section; a reading means which is set to a moving body moving on the moving route and reads the tag ID of the radio tag from the radio tag placed at the position where the moving body exists; a calculation means which calculates an arrangement space of the radio tag at the section, where the tag ID read by the reading means belongs to, based on the table information; and a position detection means which detects a current position of the moving body based on the table information and the arrangement space. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a position detection device that performs position detection using a plurality of wireless tags arranged along a movement path.

  Conventionally, a technique for detecting the current position of a moving body based on information stored in a wireless tag has been proposed. For example, in Patent Document 1, between an antenna and a wireless communication device that communicates with a wireless tag attached to an article placed in a communication range via the antenna, between the wireless tag and the wireless communication device. There has been disclosed a technique of providing a moving body (shielding body) that blocks communication and detecting the position of an article (moving body) based on identification information of a wireless tag whose wireless communication is blocked by the moving body.

  However, in the technique disclosed in Patent Document 1, since it is necessary to place all wireless tags within the communication range of the antenna, it is difficult to apply when the wireless tags are arranged over a long distance. . In this configuration, it is possible to assume a mode in which the antenna itself is moved along the wireless tag and the position of the antenna (moving body) is detected based on the identification information read from the wireless tag. In the disclosed technology, it is necessary to store identification information and position information for each wireless tag whose position is to be known. As the number of wireless tags whose position is to be known increases, the management of the identification information and the position information is performed. Since it becomes complicated, there is a problem that the burden of introduction and maintenance increases.

  The present invention has been made in view of the above, and provides a position detection device that facilitates the association between a wireless tag and position information and can reduce the burden on introduction and maintenance. Objective.

  In order to solve the above-described problems and achieve the object, the present invention is arranged along a predetermined movement path constituted by one or a plurality of sections, and is arranged from a reference position serving as a base point in the movement path. A plurality of wireless tags that store sequentially assigned numbers according to the amount of change in position as tag IDs, a marker tag ID that is a tag ID of a wireless tag located at the beginning of each section with the reference position as a base point, Storage means for storing table information in which a physical position representing a distance from the reference position of the wireless tag and a section tag number representing a total number of wireless tags arranged in a section to which the wireless tag belongs; Based on the table information, reading means that is provided on a moving body that moves along the moving path and reads a tag ID from the wireless tag disposed at a position where the moving body exists. A calculating unit that calculates a section length of a section to which the tag ID read by the reading unit belongs, and calculates an arrangement interval of the wireless tags in the section by dividing by a section tag number of the section; Based on the information and the arrangement interval, a separation distance between the tag ID read by the reading unit and the marker tag ID of the section to which the tag ID belongs is calculated, and the physical position of the marker tag ID is calculated as the separation distance. Position detecting means for detecting a value obtained by adding as a current position of the moving body.

  ADVANTAGE OF THE INVENTION According to this invention, while making the correlation with a wireless tag and position information easy, the position detection apparatus which can reduce the burden concerning the time of introduction and a maintenance can be provided.

FIG. 1 is a perspective view schematically showing a moving device according to the present embodiment. FIG. 2 is a plan view schematically showing the moving device shown in FIG. FIG. 3 is a diagram illustrating an example of a section configuration of a movement route. FIG. 4 is a diagram illustrating an example of a section configuration of a movement route. FIG. 5 is a diagram illustrating an example of the marker tag table. FIG. 6 is a flowchart illustrating a procedure of position detection processing executed by the position detection control unit. FIG. 7 is a flowchart showing the procedure of the movement speed control process executed by the movement control unit.

  Embodiments of a position detection device according to the present invention will be described below in detail with reference to the accompanying drawings. In the following, an example in which the position detection device according to the present invention is applied to a moving device that transports an object will be described, but the present invention is not limited to this embodiment.

  FIG. 1 is a perspective view schematically showing the moving device 100, and FIG. 2 is a plan view schematically showing the moving device 100. The moving device 100 is a crane device provided in, for example, a steel mill, and a pair of tracks 11 and 12 constituting the moving path 10 and a moving body 20 such as a crane truck provided so as to be movable on the tracks 11 and 12. And a plurality of wireless tags 30 arranged along the movement path 10.

  The moving body 20 engages with the tracks 11 and 12 and moves along the moving path 10 on the tracks 11 and 12. The moving body 20 includes an antenna 21, a tag reader unit 22, a position detection information storage unit 23, and a position detection control unit 24 as functional units related to position detection on the movement path 10. In addition, the moving body 20 includes an operation input unit 25, a movement control information storage unit 26, and a movement control unit 27 as functional units related to movement on the movement path 10.

  The antenna 21 is provided on a side surface of the moving body 20 facing the wireless tag 30, and reads predetermined information stored in the wireless tag 30 by irradiating a radio wave of a predetermined frequency according to the control of the tag reader unit 22.

  The wireless tag 30 includes an IC chip, an antenna, and the like (none of which are shown), and sends predetermined information stored in the IC chip to the antenna 21 by communication with the antenna 21. Here, the arrangement intervals of the wireless tags 30 (hereinafter referred to as tag intervals) are different for each predetermined section divided according to the use environment or the like. Hereinafter, the relationship between each section constituting the movement route 10 and the tag interval of the wireless tag 30 will be described.

  FIG. 3 is a diagram illustrating an example of a section configuration of the travel route 10 and illustrates an example in which the travel route 10 is divided into nine sections (section 1 to section 9). In addition, in the same figure, illustration of the mobile body 20 and the tracks 11 and 12 is omitted.

  Section 1, section 5, and section 9 (hereinafter collectively referred to as a narrowly arranged section) are provided at the entrances or entrance portions of areas A1 to A3 that serve as stop positions or movement start positions of the moving body 20. In this narrow arrangement section, since higher accuracy of position detection is required, the tag interval of the wireless tag 30 is narrower than other sections (for example, an interval of 5 cm).

  The section 3 and the section 7 (hereinafter collectively referred to as the wide arrangement section) are provided between the narrow arrangement sections, and are mainly used as a movement path between the narrow arrangement sections. In this wide arrangement section, since it is only necessary to know the approximate position, the tag interval of the wireless tag 30 is wider than the narrow arrangement section (for example, 100 cm interval).

  In addition, section 2, section 4, section 6 and section 8 (hereinafter collectively referred to as the middle arrangement section) are provided between the narrow arrangement section and the wide arrangement section, and mainly the acceleration of the moving body 20 or Used as a deceleration zone. The tag interval of the wireless tag 30 arranged in the middle arrangement section is wider than the narrow arrangement section and narrower than the wide arrangement section (for example, an interval of 10 cm).

  At one end of the movement path 10, a reference position B serving as a base point for position measurement in the movement path 10 is set, and the position of the moving body 20 is determined as a distance from the reference position B. . Each wireless tag 30 stores, as a tag ID, a sequential number sequentially assigned in accordance with the amount of change in the arrangement position from the reference position B with the position of the reference position B being “1”.

  Further, the wireless tag 30 positioned at the head of each section with the reference position B as a base point functions as a mark (marker) for determining the section to which the wireless tag 30 belongs. In a marker tag table 231 to be described later, a tag ID of each wireless tag 30 serving as a marker and a distance from the reference position B of the wireless tag 30 (hereinafter referred to as physical coordinates) are stored in association with each other. Hereinafter, the wireless tag 30 serving as a marker in each section is referred to as a marker tag 31, and the tag ID stored in the marker tag 31 is referred to as a marker tag ID.

  FIG. 4 is a diagram illustrating an example of a section configuration of the movement route 10. In the drawing, m wireless tags 30 are arranged at equal intervals in section 1. In the section 1, the wireless tag 30 arranged at the position of the physical coordinate “0” corresponding to the reference position B functions as the marker tag 31 of the section 1.

  In section 2, (n−m) wireless tags 30 are arranged at equal intervals (where n> m). In the section 2, the wireless tag 30 having a physical coordinate of 5000 cm located at the head of the section 2 when viewed from the reference position B functions as the marker tag 31. In section 3, (on) wireless tags 30 are arranged at equal intervals (where o> n). In this section 3, the wireless tag 30 with physical coordinates 7500 cm located at the beginning of the section 3 when viewed from the reference position B functions as the marker tag 31. Hereinafter, similarly in the sections 4 to 9, the wireless tag 30 positioned at the head of each section when viewed from the reference position B becomes the marker tag 31.

  Returning to FIG. 2, the tag reader unit 22 reads the tag ID stored in the wireless tag 30 by communicating with the wireless tag 30 using the antenna 21.

  The position detection information storage unit 23 is a storage medium such as an HDD, SSD, or flash ROM, and stores in advance various programs executed by the position detection control unit 24 and various setting information. The position detection information storage unit 23 stores a marker tag table 231 that stores setting information related to position detection on the movement route 10.

  Here, FIG. 5 is a diagram illustrating an example of the marker tag table 231 stored in the position detection information storage unit 23. As shown in the figure, the marker tag table 231 includes a marker tag ID of the marker tag 31, physical coordinates indicating a distance from the reference position B of the marker tag 31, and a section for each section constituting the movement route 10. The total number of wireless tags 30 (in the following, referred to as the number of section tags) is registered in association with each other.

  Note that the marker tag table 231 in FIG. 5 has m = 1000, n = 1250, o = 1350 in the example of FIG. 4 described above, and the marker tag 31 with the marker tag ID “1” belongs to it. The section belongs to section 1, the section to which the marker tag 31 with the marker tag ID “1001” belongs belongs to section 2, the section to which the marker tag 31 with the marker tag ID “1251” belongs belongs to section 3, and the marker tag ID “1351”. The sections to which the marker tag 31 belongs correspond to the sections 4 respectively.

  The position detection control unit 24 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. The position detection control unit 24 calculates in cooperation with a program stored in the position detection information storage unit 23. And it functions as a position detection means and controls the operation of each part related to the position detection of the moving body 20 in an integrated manner.

  Specifically, when the tag ID is input from the tag reader unit 22, the position detection control unit 24 refers to the marker tag table 231, and sets the maximum marker tag ID that is equal to or smaller than the tag ID value to “ ID ”is specified. Here, the belonging section marker tag ID corresponds to the section to which the mobile object 20 currently belongs. Further, the position detection control unit 24 refers to the marker tag table 231, and belongs to the section marker tag ID and a marker tag ID corresponding to the section next to the section marker tag ID when viewed from the reference position B (hereinafter, the next section). When the marker tag ID) is specified, the tag interval of the wireless tag 30 arranged in the section where the moving body 20 currently exists is calculated using the following formula (1).

  In the above formula (1), the physical position of the next section marker tag means the physical position associated with the next section marker tag ID. The physical position of the belonging section marker tag means a physical position associated with the belonging section marker tag ID. The number of section tags of the belonging section marker tag means the number of section tags associated with the belonging section marker tag ID.

  Furthermore, the position detection control unit 24 specifies the current position of the moving body 20 on the moving route 10 by calculating the following expression (2) based on the tag interval calculated by the above expression (1). The detection tag ID means a tag ID input from the tag reader unit 22.

  Specifically, the position detection control unit 24 calculates the separation distance between the detection tag ID and the belonging section marker tag ID according to the first term on the right side of the equation (2). In addition, when the position detection control unit 24 derives a value obtained by adding the physical position of the belonging section marker tag ID to the calculated separation distance in the second term on the right side, this value is used as the current position of the moving body 20 on the moving path 10. To detect. Further, the position detection control unit 24 sends the current position of the moving body 20 to the movement control unit 27.

  For example, when the tag ID (detection tag ID) input from the tag reader unit 22 is “1101”, the position detection control unit 24 refers to the marker tag table 231 in FIG. While specifying “1001” as the maximum belonging section marker tag ID, the next section marker tag ID “1251” is specified. The position detection control unit 24 then adds the physical position (7500) of the next section marker tag ID, the physical position “5000” of the belonging section marker tag ID, and the number of section tags of the belonging section marker tag ID to the above equation (1). By substituting “250”, the tag interval “10” (cm) is calculated.

  Further, the position detection control unit 24 substitutes the detection tag ID “1101”, the belonging section marker tag ID “1001”, the tag interval “10”, and the physical position “5000” of the belonging section marker tag ID into the above formula (2). As a result, the physical position of the wireless tag 30 read by the tag reader unit 22, that is, the physical position “6000” of the moving body 20 is derived. Thereby, it can be detected that the moving body 20 is at a position of “6000” (cm) from the reference position B.

  Hereinafter, the position detection operation of the moving body 20 will be described. Here, FIG. 6 is a flowchart showing a procedure of position detection processing executed by the position detection control unit 24. This process is performed every time a tag ID is input by the position detection control unit 24.

  First, when the tag ID read by the tag reader unit 22 is input to the position detection control unit 24 (step S11), a maximum belonging section marker tag ID that is equal to or smaller than the tag ID value is read from the marker tag table 231. While specifying (step S12), the next section marker tag ID) is specified (step S13).

  Subsequently, the position detection control unit 24 uses the above formula (1) to divide the section length of the section to which the tag ID input in step S11 belongs by the number of section tags in the section. The arrangement interval of the wireless tags 30 is calculated (step S14).

  Next, the position detection control unit 24 adds the physical position of the tag ID to the difference value of the physical position between the tag ID input in step S11 and the marker tag ID of the belonging section by using the above formula (2). When the obtained value is derived (step S15), this is output to the movement control unit 27 as the current position of the moving body 20 (step S16), and this process is terminated.

  As described above, in this embodiment, the mobile object is used by using the marker tag table 231 in which the marker tag ID of the wireless tag 30 (marker tag 31) located at the head of each section, the physical position, and the number of section tags are associated with each other. 20 positions are detected. Accordingly, since it is possible to reduce the amount of information related to the position detection of the moving body 20 as compared with the form in which the position information is stored for each wireless tag, the association between the wireless tag 30 and the position information (tag ID) is possible. And the burden on the marker tag table 231 during introduction and maintenance can be reduced.

  Returning to FIG. 2, the operation input unit 25 is a functional unit for the user to operate the moving body 20. Specifically, the operation input unit 25 includes an accelerator, a brake, an operation button for instructing a movement destination, and the like, and sends operation contents input by the user to the movement control unit 27 as instruction information.

  The movement control information storage unit 26 is a storage medium such as an HDD, an SSD, or a flash ROM, and previously stores various programs executed by the movement control unit 27 and various setting information. Further, the movement control unit 27 stores movement speed, acceleration, deceleration, stop position, and the like as setting information regarding movement control in each section constituting the movement route 10.

  For example, for the narrowly arranged section, the movement speed V1, the physical position that is the stop position, the brake point, and the like in the narrowly arranged section are registered in advance. Here, the brake point is a physical position determined on the basis of the braking distance and the free running distance of the moving body 20, and by starting braking at the brake point, the moving body 20 is set to a predetermined position in the narrowly arranged section. It is possible to stop at the stop position.

  Further, for the wide arrangement section, the movement speed V2 (however, V2> V1) in the wide arrangement section is registered in advance. In the middle arrangement section, acceleration from the moving speed V1 to the moving speed V2, a deceleration from the moving speed V2 to the moving speed V1, and the like are registered in advance.

  The movement control unit 27 includes a CPU, a ROM, a RAM, and the like, functions as a movement control unit in cooperation with a program stored in the position detection information storage unit 23, and is a power engine (not shown) of the moving body 20. Is controlled to move the moving body 20 along the movement path 10.

  Specifically, the movement control unit 27 includes the physical position of the moving body 20 detected by the position detection control unit 24 and the movement destination area indicated by the instruction information from the position detection control unit 24, that is, a narrow arrangement section. Based on the setting information stored in the movement control information storage unit 26, the moving speed of the moving body 20 is derived. Then, the movement control unit 27 controls the power engine so as to move the moving body 20 to the destination at the derived moving speed.

  Hereinafter, the moving speed control of the moving body 20 will be described with reference to FIG. Here, FIG. 7 is a flowchart showing the procedure of the movement speed control process executed by the movement control unit 27.

  First, the movement control unit 27 waits until an area (narrow arrangement section) that is a movement destination is designated via the operation input unit 25 (step S21; No). Here, if the narrow arrangement section of a movement destination is designated (step S21; Yes), the movement control part 27 will start the movement of the mobile body 20 toward this narrow arrangement section of a movement destination (step S22).

  Subsequently, the movement control unit 27 performs movement control based on the physical position of the moving body 20 detected by the position detection control unit 24 with the movement of step S22 and the narrow arrangement position of the movement destination specified in step S21. When the moving speed of the moving body 20 is derived from the setting information stored in the information storage unit 26 (step S23), the moving body 20 is moved at the derived moving speed (step S24).

  Next, the movement control unit 27 determines whether or not the physical position of the moving body 20 detected by the position detection control unit 24 has reached the brake point at the narrowly arranged position that is the movement destination (step S25). When it is determined that the brake point has not been reached (step S25; No), the process returns to step S23 again. If it is determined that the brake point has been reached (step S25; Yes), the movement control unit 27 starts decelerating (braking) (step S26) and ends this process.

  For example, when the position detection control unit 24 detects the physical position of the moving body 20 every 200 milliseconds, the operation when moving the moving body 20 in the section 1 to the stop position (for example, the physical position X) in the section 9. Is controlled as follows. It is assumed that no worker or the like enters the movement route 10.

  First, the movement control unit 27 starts moving the moving body 20 from the section 1 to the section 9. Next, the movement control unit 27 moves the moving body 20 based on the physical position of the moving body 20 detected by the position detection control unit 24 along with this movement and the setting information stored in the movement control information storage unit 26. Control the speed.

  Specifically, when the physical position of the moving body 20 is within the section 1, the movement control unit 27 moves the moving body 20 at the moving speed V1 (for example, 0.1 m per second) within the section 1. Next, when the physical position of the moving body 20 reaches the section 2, acceleration to the moving speed V <b> 2 (for example, 2 m / s) is started, and the moving speed V <b> 2 is increased between the section 3 and the section 7. maintain. Subsequently, when the physical position of the moving body 20 reaches the section 8, deceleration to the moving speed V1 is started. When the physical position of the moving body 20 reaches a brake point in the section 9 (for example, 1 m before the physical position X), the moving body 20 is stopped at the physical position X by starting deceleration (braking).

  As described above, the movement control unit 27 controls the moving speed of the moving body 20 according to each section constituting the moving path 10 based on the physical position detected by the position detection control unit 24.

  The embodiment of the present invention has been described above, but the present invention is not limited to this, and various modifications, substitutions, additions, and the like are possible without departing from the spirit of the present invention.

  For example, the position detection control unit 24 and the movement control unit 27 may be realized by the same hardware (CPU, ROM, RAM, etc.), or may be realized individually by different hardware. Good. Further, the position detection information storage unit 23 and the movement control information storage unit 26 may be realized by the same storage medium, or may be realized individually by different storage media.

  Moreover, although the example which divided the movement path | route 10 into nine areas was shown in the said embodiment, it is not restricted to this, For example, it is good also as a form which makes the movement path | route 10 a some area other than nine, It is good also as a form made into this area. In the case of a single section, the marker tag table 231 includes the marker tag ID, physical coordinates, and number of section tags of the wireless tag 30 located at the beginning of the section, that is, the reference position B, at the end of the section. It is assumed that the physical position of the wireless tag 30 that is positioned is stored as the physical position of the next section marker tag.

  Moreover, in the said embodiment, although the movement path | route 10 was made into linear form, it may not be restricted to this but may be curvilinear form, and it is good also as a loop form.

DESCRIPTION OF SYMBOLS 100 Mobile device 10 Movement path 11 Line 12 Line 20 Mobile body 21 Antenna 22 Tag reader part 23 Position detection information storage part 231 Marker tag table 24 Position detection control part 25 Operation input part 26 Movement control information storage part 27 Movement control part 30 Wireless tag 31 Marker tag

JP 2009-115746 A

Claims (6)

A number that is arranged along a predetermined movement route constituted by one or a plurality of sections and that is sequentially assigned according to the amount of change in the arrangement position from the reference position serving as a base point in the movement route is stored as a tag ID. Multiple wireless tags,
Marker tag ID, which is a tag ID of a wireless tag located at the beginning of each section with the reference position as a base point, a physical position indicating the distance of the wireless tag from the reference position, and a section to which the wireless tag belongs Storage means for storing table information in which the number of section tags representing the total number of arranged wireless tags is associated;
A reading unit that is provided in a moving body that moves along the moving path and reads a tag ID from the wireless tag disposed at a position where the moving body exists;
Based on the table information, the section length of the section to which the tag ID read by the reading unit belongs is calculated, and the arrangement interval of the wireless tags in the section is calculated by dividing by the number of section tags in the section. Calculating means for
Based on the table information and the arrangement interval, a separation distance between the tag ID read by the reading unit and a marker tag ID of a section to which the tag ID belongs is calculated, and the separation distance of the marker tag ID is calculated as the separation distance. Position detecting means for detecting a value obtained by adding physical positions as a current position of the moving body;
A position detection device comprising:   The calculating means associates the physical position associated with the marker tag ID of the section to which the tag ID read by the reading means belongs to the marker tag ID of the next section of the section based on the reference position. The section length is derived by subtracting from the physical position, and the section length is divided by the number of section tags associated with the marker tag ID of the section to which the tag ID read by the reading unit belongs, The position detection apparatus according to claim 1, wherein an arrangement interval is calculated.   The position detecting means multiplies the arrangement distance calculated by the calculating means by multiplying the result obtained by subtracting the marker tag ID of the section to which the tag ID belongs from the tag ID read by the reading means. The current position of the mobile body is derived by calculating and adding the physical position associated with the marker tag ID of the section to which the tag ID read by the reading unit belongs to the separation distance. Item 3. The position detection device according to Item 1 or 2.   The position detection device according to any one of claims 1 to 3, wherein the number of section tags is different in a part or all of a plurality of sections constituting the movement route.   The position detection device according to claim 4, wherein the number of section tags in each section is determined according to a moving speed of each section of the moving body.   6. The apparatus according to claim 1, further comprising movement control means for controlling a moving speed of the moving body according to a current position of the moving body detected by the position detecting means. The position detection device described.

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