Reading apparatus and information processing system

Abstract

To reduce redundant information as much as possible while maintaining useful information collected through wireless communication.SOLUTION: A reading apparatus comprises: reading means for periodically attempting to read information from a wireless device within a reading range; storage means; and control means for causing the storage means to store, if the reading means reads first identification information from a first wireless device, at least the first identification information and a read result indicating the time when the first identification information was read. The control means, if the first identification information is read multiple times from the first wireless device, selectively stores in the storage means a first read result and a second read result from the read results corresponding to the multiple reads. The first read result corresponds to the entry point when the first wireless device entered the reading range. The second read result corresponds to the exit point when the first wireless device exited the reading range.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a reading device and an information providing system. [Background technology]

[0002] RFID (Radio Frequency Identification) is a technology that enables information embedded in small devices, also known as tags, to be read by an external reader via near-field wireless communication. For example, by attaching an RFID tag with embedded unique identification information to an item, it becomes possible to efficiently track the item's location and easily visualize information about the items under management. Among these, passive RFID tags, which transmit information using the energy of electromagnetic waves emitted from a reader, are being used in a wide range of applications because they do not require batteries, are inexpensive to manufacture, and can operate semi-permanently.

[0003] Patent Document 1 discloses an example of a system that visualizes the location information of managed objects such as movable objects and users in real space. In the system of Patent Document 1, RFID tags (location tags) are fixedly installed in real space, RFID tags (target tags) are attached to managed objects, and the latest location of the managed objects is estimated based on information read from the RFID tags by a tag reader.

[0004] Patent Document 2 discloses an example of a system that utilizes RFID tags to reduce the operational burden on users (employees) who are the subject of management in the application of attendance management. In the system of Patent Document 2, while a user is staying at a work location, a reader / writer installed near the work location writes time information indicating the start and end times of work into the memory of an RFID tag carried by the user. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2024-25974 [Patent Document 2] Patent No. 4626937 Summary of the Invention [Problem to be solved by the invention]

[0006] When adopting a configuration that periodically reads information from an RFID tag without relying on user operation, such as the tag reader described in Patent Document 1, the more frequently the reading is performed, the better the information tracking performance will be, but the more redundant information will be accumulated in the device. In situations where there are limitations on available memory or communication capacity, it is desirable to reduce redundant information as much as possible.

[0007] In view of the above, the present invention aims to provide a mechanism that can reduce redundant information as much as possible while maintaining useful information collected through wireless communication. [Means for solving the problem]

[0008] According to one aspect, there is provided a reading apparatus including: reading means for periodically attempting to read information from a wireless device within a reading range; storage means; and control means for, when first identification information is read from a first wireless device by the reading means, storing in the storage means a reading result indicating at least the first identification information and a reading time of the first identification information. When the first identification information is read from the first wireless device multiple times, the control means selectively stores in the storage means a first reading result corresponding to the entry time of the first wireless device into the reading range and a second reading result corresponding to the exit time of the first wireless device from the reading range, from the reading results corresponding to the multiple readings. Selectively storing the first read result and the second read result in the storage means includes at least one of not storing in the storage means at least one read result that does not correspond to the first read result and the second read result, and deleting from the storage means at least one read result that does not correspond to the first read result and the second read result among the read results temporarily stored in the storage means. There is also provided an information provision system including the reading device and an information processing device that receives the first read result and the second read result from the reading device, wherein the information processing device provides location information based on the first read result and the second read result to a user. [Effects of the Invention]

[0009] According to the present invention, it is possible to reduce redundant information as much as possible while maintaining useful information collected through wireless communication. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing an example of a configuration of an information management system according to an embodiment. [Figure 2] FIG. 2 is a block diagram showing an example of the configuration of a tag reader according to an embodiment. [Figure 3] FIG. 2 is a block diagram showing an example of the configuration of a management server according to an embodiment. [Figure 4A] FIG. 4 is an explanatory diagram showing an example of the configuration of an item table according to an embodiment. [Figure 4B] FIG. 4 is an explanatory diagram showing an example of the configuration of a position tag table according to an embodiment. [Figure 4C] FIG. 4 is an explanatory diagram showing an example of the configuration of a reader table according to an embodiment; [Figure 4D] FIG. 4 is an explanatory diagram showing an example of the configuration of a tag detection table according to an embodiment. [Figure 4E] FIG. 4 is an explanatory diagram showing an example of the configuration of an item history table according to an embodiment. [Figure 4F] FIG. 4 is an explanatory diagram showing an example of the configuration of a position tag monitoring table according to an embodiment. [Figure 5] 10 is a flowchart showing an example of the flow of a read attempt process that can be executed by a tag reader. [Figure 6] FIG. 10 is an explanatory diagram for selecting a reading result in the first embodiment. [Figure 7] 10 is a flowchart showing an example of the flow of a data selection process according to the first embodiment. [Figure 8] FIG. 10 is an explanatory diagram for selecting a reading result in a modified example of the first embodiment. [Figure 9] FIG. 10 is an explanatory diagram for selecting a reading result in the second embodiment. [Figure 10] 10 is a flowchart showing an example of the flow of a data selection process according to the second embodiment. [Figure 11] FIG. 11 is an explanatory diagram for selecting a reading result in the third embodiment. [Figure 12] 10 is a flowchart showing an example of the flow of a data selection process according to the third embodiment. [Figure 13] FIG. 11 is an explanatory diagram of monitoring of position tags in a modified example of the third embodiment. [Figure 14] FIG. 13 is an explanatory diagram for selecting a reading result in the fourth embodiment. [Figure 15] FIG. 10 is an explanatory diagram of an example of communication from a tag reader to a management server via a relay device. [Figure 16] FIG. 13 is an explanatory diagram for selecting a reading result in the fifth embodiment. [Figure 17] 10 is a flowchart showing an example of the flow of a position estimation process that can be executed by the management server. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0012] <1. System Overview> FIG. 1 is a schematic diagram showing an example of the configuration of an information provision system 1 according to an embodiment. The information provision system 1 tracks the location of a managed object, which may change daily, and provides the location information to a user. In this embodiment, the managed object is an object existing in a real space. The object may be an inanimate object (e.g., a machine, equipment, appliance, material, consumer good, part, household goods, vehicle, or robot) or a living object (e.g., an animal or plant). The object may move by being carried by a user or a machine, or may move autonomously. In another embodiment, the managed object may be a person (e.g., a company employee, a construction worker, or an event participant). The real space may be, for example, an area on the ground, a building, or a floor within a building. In the example of FIG. 1, objects 30a and 30b exist in a real space 10.

[0013] The information providing system 1 utilizes wireless devices, also called tags, to track the locations of managed objects. In particular, in this embodiment, the information providing system 1 includes at least one location tag and at least one object tag.

[0014] The target tag is an RFID tag (first wireless device) attached to a movable managed object in the real space 10. In the example of FIG. 1, a target tag 50a is attached to an item 30a, and a target tag 50b is attached to an item 30b. Each target tag stores identification information (first identification information) for identifying the managed object to which the target tag is attached in an internal memory. In an embodiment in which people are the managed objects, the target tag may be held, carried, or attached by each person, and in this specification, such a situation is also expressed as the target tag being "attached" to the managed object.

[0015] The position tag is an RFID tag (second wireless device) that is fixedly installed at a known position in the real space 10. In the example of Fig. 1, three position tags 40a, 40b, and 40c are installed in the real space 10. Each position tag stores unique identification information (second identification information) in an internal memory.

[0016] In this embodiment, each of the tags, such as the position tag 40 and the target tag 50, is assumed to be a passive RFID tag (passive tag). A passive tag is composed of a small IC (Integrated Circuit) chip with built-in memory and an antenna, and stores unique identification information and other information in the memory. In this specification, the identification information is simply referred to as an ID, and the identification information that identifies the tag is also referred to as a tag ID. Note that the tag ID may also be considered as information that identifies the object to which the tag is attached. The IC chip of the passive tag operates using the energy of electromagnetic waves emitted from a tag reader, modulates the tag ID and other information stored in the memory into an information signal, and transmits (returns) the information signal from the antenna.

[0017] In another embodiment, each tag may be an active RFID tag. When each tag actively (e.g., periodically) transmits information to the surroundings using power from a built-in battery, the tag may be called a beacon tag. In yet another embodiment, each tag may be a wireless device that responds to a signal from a reader and returns information using, for example, the NFC (Near Field Communication) method or the Bluetooth (registered trademark) method. Each tag may be called any name, such as an IC tag, an IC card, or a responder.

[0018] The information providing system 1 further includes at least one reading device (also called a tag reader) for reading information from wireless devices. Three tag readers 100a, 100b, and 100c are shown in Figure 1.

[0019] Tag reader 100a is a reading device carried by user 20a. Tag reader 100a periodically attempts to read information from wireless devices within read range 105a. In the example of Figure 1, tag reader 100a can read the tag ID of location tag 40a from location tag 40a located within read range 105a.

[0020] Tag readers 100b and 100c are reading devices installed near location tags 40b and 40c, respectively. Tag readers 100b and 100c periodically attempt to read information from wireless devices within read ranges 105b and 105c, respectively. In the example of Fig. 1, tag reader 100b can read the tag ID of location tag 40b from location tag 40b located within read range 105b.

[0021] Users 20a and 20b move freely within real space 10. User 20a carries tag reader 100a. In this specification, the expression "a user carries an object" broadly encompasses various ways in which the user moves with the object (for example, moving while holding or wearing the object). After tag reader 100a reads the tag ID of position tag 40a, when user 20a moves in the direction of arrow A1, item 30a enters reading range 105a of tag reader 100a. Then, tag reader 100a can read the tag ID of target tag 50a from target tag 50a on item 30a.

[0022] User 20b is carrying item 30b. When user 20b moves in the direction of arrow A2, item 30b enters reading range 105b of tag reader 100b. Tag reader 100b can then read the tag ID of target tag 50b from target tag 50b on item 30b.

[0023] In the following description, when there is no need to distinguish between tag readers 100a to 100c, the alphabet at the end of the reference numeral will be omitted and they will be collectively referred to as tag reader 100. The same applies to users 20 (users 20a, 20b), items 30 (items 30a, 30b), position tags 40 (position tags 40a to 40c), target tags 50 (target tags 50a, 50b), and other elements.

[0024] 1 shows an example in which the read range 105 of each tag reader 100 is circular or elliptical, but the technology of the present disclosure is not limited to such examples. The read range of a tag reader with an omnidirectional antenna may be approximately circular, while the read range of a tag reader with a directional antenna may be approximately sector-shaped. The shape of the read range may also change depending on the presence of obstacles that block the radio signal.

[0025] Tag reader 100b is used to monitor the operating status of position tag 40b. Similarly, tag reader 100c is used to monitor the operating status of position tag 40c. In the following description, a tag reader that is portable and carried by a user, such as tag reader 100a, is also referred to as a mobile reader, and tag readers that are fixedly installed, such as tag readers 100b and 100c, are also referred to as a fixed reader. Fixed readers may be installed at any location suitable for wireless communication, such as a partition wall within an area, or a pillar, wall, or ceiling surface within a building. An example of a specific configuration of tag reader 100 will be further described later.

[0026] The tag readers 100, the terminal devices 160, and the management server 200 are connected to a network 5. The network 5 may be a wired network, a wireless network, or any combination thereof. Examples of the network 5 may include the Internet, an intranet, and a cloud network. Each tag reader 100 may be able to communicate directly with the management server 200, or may be able to communicate indirectly with the management server 200 via some kind of relay device (not shown). For example, the user 20 may carry a user terminal along with a mobile reader, and the user terminal may forward data received from the mobile reader to the management server 200. Also, a relay device that relays communication between the fixed readers and the management server 200 may be installed in the real space 10. One relay device may provide the communication relay function to multiple fixed readers.

[0027] The terminal device 160 is an information processing device used by the user 20 or other administrative users. The terminal device 160 may be, for example, a general-purpose computer such as a PC (Personal Computer) or a smartphone, or may be a dedicated terminal device provided for managing and viewing location information. The terminal device 160 typically has a processor, memory, an input device, and a display. The terminal device 160 accepts information requests from users and displays information provided by the management server 200 on the screen of a web browser or an information viewing application.

[0028] The management server 200 is an information processing device that stores location information and other information of the items 30 in a database. The management server 200 may be implemented, for example, as an application server, a database server, or a cloud server using a high-performance general-purpose computer. While a single management server 200 is shown in FIG. 1 , the functions of the management server 200, which will be described in detail later, may be provided by a single device, or may be provided by multiple physically separate devices working together. Furthermore, although the present embodiment describes an example in which the management server 200 stores the database, a device separate from the management server 200 may store part or all of the database.

[0029] The management server 200 receives tag reading results from the tag reader 100 and estimates the position of each item 30 based on the received tag reading results. For example, if the tag reader 100a reads the tag IDs from the position tag 40a and the target tag 50a within a short period of time, the management server 200 can estimate that the item 30a is located near the position tag 40a. If the tag reader 100a has a movement amount measurement function (described later), the management server 200 can also estimate the position of the item 30a more precisely based on the known installation position of the position tag 40a and the relative movement amount of the tag reader 100a. An example of a specific configuration of the management server 200 will be further described later.

[0030] Each tag reader 100 in the information providing system 1 periodically attempts to read information from an RFID tag without relying on user operation. The more frequently the attempts are made, the better the tracking performance of the location of the managed object. On the other hand, reading information frequently generates a large amount of redundant information indicating the read results. In many cases, the memory and communication resources available to the tag reader 100 are limited, so it is desirable to reduce redundant information as much as possible. Therefore, several embodiments for reducing redundant information as much as possible while maintaining useful information in the tag reader 100 will be described in detail below.

[0031] <2. Tag reader configuration example> Fig. 2 is a block diagram showing an example of the configuration of tag reader 100 according to an embodiment. Referring to Fig. 2, tag reader 100 includes control unit 111, storage unit 112, communication unit 113, operation unit 115, reading unit 116, and power supply 117. In one embodiment, tag reader 100, which is a mobile reader, may further include measurement unit 114.

[0032] Control unit 111 is a control means that includes a memory that stores computer programs and one or more processors (e.g., CPUs (Central Processing Units)) that execute the computer programs. Control unit 111 controls all of the functions of the tag reader described in this specification.

[0033] The storage unit 112 is a storage means for storing information read from the wireless device by the reading unit 116. The storage unit 112 may include any type of storage medium, such as a semiconductor memory, an optical disk, or a magnetic disk.

[0034] The communication unit 113 is a communication means for communicating with an external device. For example, the communication unit 113 may be a WLAN (Wireless Local Area Network) interface for communicating with a WLAN access point, or a cellular communication interface for communicating with a cellular base station. The communication unit 113 may also be a connection interface for connecting with a relay device (for example, a Bluetooth (registered trademark) interface or a USB (Universal Serial Bus) interface).

[0035] The measurement unit 114 is a measurement means for measuring the relative movement amount of the tag reader 100. For example, the measurement unit 114 measures the relative movement amount of the tag reader 100 from a certain reference position using a self-position estimation technology also known as PDR (Pedestrian Dead Reckoning). When the measurement unit 114 uses PDR, the measurement unit 114 includes a three-axis acceleration sensor, a gyro sensor, and a geomagnetic sensor. The measurement unit 114 may measure the relative movement amount using any known self-position estimation technology, and detailed description thereof will be omitted here. The measurement unit 114 may be capable of recognizing the walking steps and stride length of the user 20 carrying the tag reader 100. In one variation, the measurement unit 114 may further include a barometric pressure sensor used to estimate the relative height from the reference position. The movement amount measured by the measurement unit 114 may be represented by a two-dimensional vector in a horizontal plane or a three-dimensional vector including a height component. If tag reader 100 is a fixed reader, measuring section 114 may be omitted.

[0036] The operation unit 115 accepts operations by the user 20. The operation unit 115 includes, for example, a physical input device such as a button, switch, or lever disposed on the housing of the tag reader. The operation unit 115 accepts operations by the user 20 via the input device and outputs an operation signal to the control unit 111. The operation unit 115 may also include a voice input interface such as a microphone.

[0037] The reader 116 is a reading means for reading information from a wireless device. Referring to FIG. 2, the reader 116 includes an RF controller 120, a power amplifier 121, a filter 122, a first coupler 123, a second coupler 124, an antenna 125, a power detection unit 126, and a canceller 127. The RF controller 120 outputs a transmission signal (e.g., a signal modulated in the UHF band) from the TX terminal to the power amplifier 121 under the control of the control unit 111. The power amplifier 121 amplifies the transmission signal input from the RF controller 120 and outputs it to the filter 122. The filter 122 may be, for example, a low-pass filter, and removes unnecessary frequency components from the transmission signal amplified by the power amplifier 121. The first coupler 123 distributes the transmission signal that has passed through the filter 122 to the second coupler 124 and the power detection unit 126. The second coupler 124 outputs the transmission signal input from the first coupler 123 to the antenna 125, and outputs the reception signal input from the antenna 125 to the RF controller 120. The antenna 125 transmits the transmission signal input from the second coupler 124 into the air as an electromagnetic wave. The antenna 125 also receives a signal returned from an RFID tag present within the reading range of the tag reader in response to the transmission signal, and outputs the reception signal to the second coupler 124. The power detection unit 126 detects the power level of the signal input from the first coupler 123 and outputs a signal RF_DETECT indicating the detected power level to the control unit 111. The canceller 127 receives a signal CARRIER_CANCEL indicating the power level of the carrier wave from the control unit 111. The canceller 127 then extracts the desired signal component of the reception signal to be output to the RX terminal of the RF controller 120 by canceling the carrier wave component of the transmission signal based on CARRIER_CANCEL. The RF controller 120 demodulates the signal input from the RX terminal, acquires the tag ID and other information returned from the RFID tag, and outputs the acquired information to the control unit 111. The RF controller 120 also measures the received signal strength of the signal input from the RX terminal, and outputs the measurement result to the control unit 111.

[0038] Power supply 117 is a power supply means that supplies power to control unit 111, memory unit 112, communication unit 113, measurement unit 114, operation unit 115, and reading unit 116 of tag reader 100 to operate electronic circuits. For example, power supply 117 includes a battery and a DC-DC converter. The battery may be a primary battery or a rechargeable secondary battery. Although not shown, tag reader 100 may have a connection terminal for connecting tag reader 100 to an external power source to charge power supply 117.

[0039] In this embodiment, the reading unit 116 may periodically attempt to read without requiring an explicit instruction from the user. The period of the attempts (hereinafter also referred to as the reading period) may be, for example, one second or several seconds. When the reading unit 116 reads information from an RFID tag, the control unit 111 temporarily stores the reading results in the memory unit 112. Each reading result includes at least the tag ID that was read and the time when the tag ID was read. Each reading result may also include the received signal strength measured when the tag ID was read. Furthermore, if the tag reader 100 is a mobile reader, each reading result may also include the amount of relative movement measured when the tag ID was read.

[0040] In order to prevent a large amount of redundant information from being accumulated in the storage unit 112, the control unit 111 executes a data selection process, which will be described later, to select the read results to be held in the storage unit 112. As a result of the data selection process, the amount of data stored in the storage unit 112 is reduced. Furthermore, the control unit 111 reads out the read results selected by the data selection process from the storage unit 112, and transmits them together with the reader identification information (also referred to as a reader ID) of its own device to the management server 200 via the communication unit 113. The control unit 111 deletes the data that has been transmitted to the management server 200 from the storage unit 112.

[0041] <3. Management Server Configuration Example> <3-1. General configuration> 3 is a block diagram showing an example of the configuration of the management server 200 according to an embodiment. Referring to FIG. 3, the management server 200 includes a communication unit 210, a location information database (DB) 220, and an information processing unit 230.

[0042] The communication unit 210 is a communication interface that allows the management server 200 to communicate with other devices. The communication unit 210 may be a wired communication interface or a wireless communication interface. In this embodiment, the communication unit 210 communicates with the tag reader 100 and the terminal device 160. The location information DB 220 is a database that stores various data for estimating the location of managed objects and managing location information. In this embodiment, the location information DB 220 includes an item table 310, a location tag table 320, a reader table 330, a tag detection table 340, an item history table 350, and a location tag monitoring table 360. The information processing unit 230 is a collection of multiple software modules that perform various processes related to location estimation and providing location information to users. Each software module can be operated by one or more processors (not shown) of the management server 200 executing a computer program stored in a memory (not shown). In this embodiment, the information processing unit 230 includes a data management unit 231 , an estimation unit 232 , a monitoring unit 233 , and an information providing unit 234 .

[0043] <3-2. Data configuration example> (1) Item table 4A shows an example of the configuration of an item table 310. The item table 310 has three data items: item ID 311, tag ID 312, and name 313. The item ID 311 is identification information that uniquely identifies each item 30. The tag ID 312 is identification information that uniquely identifies the target tag 50 attached to each item 30. The value of the tag ID 312 is the same as the value of the tag ID stored internally in the corresponding target tag 50. The name 313 indicates the name of each item.

[0044] (2) Location tag table FIG. 4B shows an example of the configuration of the position tag table 320. The position tag table 320 has four data items: a position ID 321, a tag ID 322, a name 323, and coordinates 324. The position ID 321 is identification information that uniquely identifies the installation location of each position tag 40. The tag ID 322 is identification information that uniquely identifies each position tag 40. The value of the tag ID 322 is the same as the tag ID value stored internally in the corresponding position tag 40. The name 323 represents a name assigned to each installation location. The coordinates 324 represent the installation location of each position tag 40 in the form of position coordinates in the coordinate system of the real space 10. While FIG. 4B shows an example in which the position coordinates are two-dimensional coordinates, the position coordinates may also be three-dimensional coordinates. The coordinate system of the real space 10 may represent relative coordinates with a specific point under the control of the system as the origin, or may represent absolute coordinates using latitude and longitude (and altitude).

[0045] (3) Leader table 4C shows an example of the configuration of reader table 330. Reader table 330 has four data items: reader ID 331, name 332, type 333, and installation location 334. Reader ID 331 is identification information that uniquely identifies each tag reader 100 used in the system. Name 332 indicates the name of each tag reader 100. Type 333 indicates whether each tag reader 100 is a mobile reader or a fixed reader. Installation location 334 indicates the installation location of tag reader 100 that is a fixed reader in the form of position coordinates in the coordinate system of real space 10.

[0046] (4) Data registration The data management unit 231 manages various data stored in the position information DB 220. For example, the data management unit 231 may receive, via the communication unit 210, a data file describing data to be stored in the item table 310, the position tag table 320, and the reader table 330, and register the data in each table. The data management unit 231 may also provide the terminal device 200 with a data management screen for accepting registration, modification, or deletion of data.

[0047] <3-3. Location information management> The tag detection table 340 and the item history table 350 in the location information DB 220 are used to estimate and track the location of each item 30 under the management of the system. The data management unit 231 adds each record of the reading result data (hereinafter referred to as tag detection record) received from the tag reader 100 via the communication unit 210 to the tag detection table 340.

[0048] (1) Tag detection table FIG. 4D shows an example of the configuration of the tag detection table 340. The tag detection table 340 has seven data items: record number 341, read time 342, reader ID 343, tag ID 344, movement amount 345, intensity 346, and detection type 347. The record number 341 is a number that uniquely identifies each tag detection record stored in the tag detection table 340. The read time 342 indicates the date and time when the tag ID was read for each tag detection record. The reader ID 343 indicates the tag reader 100 that read the tag ID for each tag detection record by the value of the reader ID 331 in the reader table 330. The tag ID 344 indicates the tag ID read for each tag detection record. The movement amount 345 represents the relative movement amount measured by the tag reader 100 when reading the tag ID for each tag detection record in the form of a two-dimensional vector in the coordinate system of the real space 10. Strength 346 represents the value of the received signal strength measured by tag reader 100 when reading the tag ID for each tag detection record. Detection type 347 represents the type of read result determined by tag reader 100 for the tag detection record indicating the read result of the tag ID of target tag 50. The values ​​of detection type 347 are described further below.

[0049] (2) Location estimation The estimation unit 232 estimates the location of each item 30 based on the read result data received from the tag reader 100. As a first example, assume that a fixed reader reads the tag ID from a target tag 50a attached to an item 30a at a first read time. Based on this read result, the estimation unit 232 can estimate that the item 30a is located near the installation position of the fixed reader.

[0050] As a second example, suppose a fixed or mobile reader reads the tag ID from target tag 50b attached to item 30b at a second read time, and then reads the tag ID from position tag 40b at a third read time. The second read time may be before or after the first read time. However, it is assumed that the time difference between the first and second read times is less than a predetermined threshold. Based on these read results, estimation unit 232 can estimate that item 30b is located near the installation location of position tag 40b.

[0051] As a third example, a mobile reader reads a tag ID from a position tag 40a at a fourth read time and then reads a tag ID from a target tag 50a attached to an item 30a at a fifth read time. The fifth read time may be before or after the fourth read time. The mobile reader also includes a measurement unit 114, and the relative movement amounts measured at the fourth and fifth read times are included in the read result data transmitted to the management server 200. Based on these read results, the estimation unit 232 can estimate the coordinates of the location where the item 30a was located at the fifth read time. Specifically, the position coordinates of the item 30a may correspond to the sum of the coordinates of the known installation location of the position tag 40a and the relative movement amount of the mobile reader from the fourth read time to the fifth read time.

[0052] When there are multiple tag detection records for the same target tag 50, the estimation unit 232 may estimate that the item 30 to which the target tag 50 is attached is located at the center of gravity of multiple position coordinates estimated using the tag detection records. Alternatively, the estimation unit 232 may estimate that the item 30 to which the target tag 50 is attached has moved so as to pass through multiple position coordinates estimated using the multiple tag detection records.

[0053] (3) Item History Table The estimation unit 232 estimates the location of each item 30 using one of the above-mentioned methods and adds an estimation result record to the item history table 350 based on the estimation result. FIG. 4E shows an example of the configuration of the item history table 350. The item history table 350 has six data items: record number 351, item 352, read time 353, location ID 354, estimated location 355, and detection type 356. The record number 351 is a number that uniquely identifies each estimation result record stored in the item history table 350. The item 352 indicates which item 30 each estimation result record indicates by using the value of the item ID 311 in the item table 310. The read time 353 indicates the date and time when the tag ID was read for each estimation result record. The location ID 354 indicates which location tag 40 the detected item 30 for each estimation result record is estimated to be located near by using the value of the location ID 321 in the location tag table 320. The estimated location 355 indicates the location coordinates of the item 30 estimated using the relative movement amount of the mobile reader for each estimation result record. The value of the detection type 356 may be the same as the value of the detection type 347 of the corresponding tag detection record in the tag detection table 340.

[0054] (4) Location tag monitoring table The monitoring unit 233 monitors the status of each position tag 40 (and fixed readers) based on the read result data received from the tag reader 100. The position tag monitoring table 360 ​​in the position information DB 220 is used to monitor the status of each position tag 40 under the management of the system. FIG. 4F shows an example of the configuration of the position tag monitoring table 360. The position tag monitoring table 360 ​​has four data items: tag ID 361, last update 362, last detection 363, and reader ID 364. The tag ID 361 indicates each monitored position tag 40 by the value of the tag ID 322 in the position tag table 320. The last update 362 indicates the date and time when each record was last updated by the monitoring unit 233. The last detection 363 indicates the date and time when the position tag 40 corresponding to each record was last detected by any tag reader 100. The reader ID 364 indicates the tag reader 100 that last detected the position tag 40 corresponding to each record by the value of the reader ID 331 in the reader table 330 .

[0055] (5) Detection of abnormalities When a tag detection record indicating the result of reading the tag ID from a position tag 40 is added to the tag detection table 340, the monitoring unit 233 updates the corresponding record in the position tag monitoring table 360 ​​based on the reading result. The monitoring unit 233 also determines whether each position tag 40 is operating normally based on the elapsed time since the date and time indicated by the last detection 363 in the position tag monitoring table 360. For example, if a position tag 40 is not detected by any tag reader 100 for a time exceeding a certain anomaly detection threshold from the date and time of last detection, the monitoring unit 233 may determine that the position tag 40 is not operating normally due to a malfunction or removal by a user. This anomaly detection threshold may be set to a different value for a position tag with a fixed reader installed nearby (position tags 40b and 40c in the example of FIG. 1) and another position tag (position tag 40a in the example of FIG. 1). Furthermore, the monitoring unit 233 may determine that a fixed reader is not operating normally based on the fact that the fixed reader does not detect a nearby position tag 40. If there is a position tag 40 or fixed reader that is not operating normally, the monitoring unit 233 outputs an alarm (for example, a warning on the screen of the terminal device 160 or sending an alarm email) to the administrative user of the information providing system 1. Note that the determination of the abnormality described above may be made by the administrative user referring to the contents of the position tag monitoring table 360, rather than by the monitoring unit 233.

[0056] <3-4. Providing location information> The information providing unit 234 provides the user with the location information managed in the location information DB 220. For example, the terminal device 160 provides a user interface for the user 20 to request location information from the management server 200 and for the management server 200 to display the location information output in response to the request. The format of the user interface provided by the terminal device 160 may be any known format (see, for example, Patent Document 1). As one example, the information providing unit 234 may display on a screen a list of items 30 located at a location specified by the user 20. As another example, the information providing unit 234 may plot, on a map of the location specified by the user 20, an icon representing an item 30 estimated to be located at that location. Instead of displaying the location information on a screen, the information providing unit 234 may transmit a data file describing the location information to the terminal device 160.

[0057] Although an example of the configuration of the location information DB 220 has been described in this section, the configuration of the location information DB 220 is not limited to the example described here. Two or more tables described above may be integrated into one table, or one table may be separated into two or more tables. Each table may have additional data items, or may not have one or more of the data items described. For example, each table may have a data item that indicates the date and time when a record was added to the table.

[0058] <4. Reduction of redundant data> The control unit 111 of the tag reader 100 performs a data selection process on the read results output from the reading unit 116 in order to reduce redundant information as much as possible while maintaining useful information to be transmitted to the management server 200. As an example, assume that a tag ID is read multiple times from a certain target tag 50 by one tag reader 100. In this case, the control unit 111 selects a first read result corresponding to the point in time when the target tag 50 entered the read range 105 of the tag reader 100 from the read results corresponding to the multiple reads. In addition, the control unit 111 selects a second read result corresponding to the point in time when the target tag 50 left the read range 105 of the tag reader 100. Then, the control unit 111 selectively stores the first read result and the second read result in the memory unit 112.

[0059] The control unit 111 may include, in a first read result corresponding to the time when tag reader 100 entered read range 105, information indicating that the read result corresponds to the time of entry. Similarly, the control unit 111 may include, in a second read result corresponding to the time when tag reader 100 left read range 105, information indicating that the read result corresponds to the time of leaving. The value "IN" of detection type 347 in tag detection table 340 means that the read result indicated by the tag detection record corresponds to the time when tag reader 100 entered read range 105. The value "OUT" of detection type 347 means that the read result indicated by the tag detection record corresponds to the time when tag reader 100 left read range 105. The same applies to the value of detection type 356 in item history table 350. By having tag reader 100 include this information in the reading results and send them to management server 200, management server 200 can recognize when and for how long each item 30 stayed within tag reader 100's reading range 105, even if there are no intermediate reading results.

[0060] The above-described entry detection and departure detection may be applied not only to the target tag 50 but also to the position tag 40. For example, when a mobile reader passes near the position tag 40, the position tag 40 enters the reading range of the mobile reader at one point in time, and then leaves the reading range at another point in time thereafter. Between these two points in time, the position tag 40 remains within the reading range of the mobile reader.

[0061] If an RFID tag is already located within the read range 105 when the reading unit 116 is activated, the entry time may be considered to be the time when the reading unit 116 is activated. Also, if an RFID tag is located within the read range 105 when the reading unit 116 stops operating, the departure time may be considered to be the time when the reading unit 116 stops operating.

[0062] Selectively storing the first read result and the second read result in the storage unit 112 may include discarding at least one read result that does not correspond to the first read result or the second read result without storing it in the storage unit 112. Alternatively, selectively storing the first read result and the second read result in the storage unit 112 may include deleting from the storage unit 112 at least one read result that does not correspond to the first read result or the second read result, among the read results temporarily stored in the storage unit 112. In either case, the at least one read result that is discarded or deleted is not transmitted to the management server 200.

[0063] <4-1. Read attempt process> In the following description, it is assumed that the read result output from reading unit 116 is temporarily stored in memory unit 112. Figure 5 is a flowchart showing an example of the flow of a read attempt process that can be executed by tag reader 100. In the following description, processing steps will be abbreviated as "S (step)."

[0064] When tag reader 100 is activated, first, in S11, reading unit 116 attempts to read the tag ID from a nearby RFID tag by emitting electromagnetic waves within reading range 105. If the result of the attempt is that a tag ID is received from a nearby RFID tag using the energy of the electromagnetic waves (S12-YES), the process proceeds to S13. On the other hand, if a tag ID is not received (S12-NO), the process returns to S11.

[0065] In S13, the reading unit 116 measures the signal strength of a signal received from a nearby RFID tag. The reading unit 116 outputs the received tag ID and the measured signal strength to the control unit 111. Next, in S14, the control unit 111 references an internal real-time clock to obtain the current time as the reading time.

[0066] S15 is executed when tag reader 100 has measurement unit 114. In S15, measurement unit 114 measures the amount of relative movement of tag reader 100 from the reference position. Measurement unit 114 outputs the measured amount of relative movement to control unit 111.

[0067] Next, in S16, the control unit 111 stores the reading result indicating the tag ID, reading time, and signal strength of the RFID tag detected by the reading unit 116 in the memory unit 112. If the relative movement amount is measured in S15, the control unit 111 may further include the measured relative movement amount in the reading result.

[0068] Thereafter, the process returns to S11. Such a read attempt process can be performed periodically at a read cycle that is set in advance in tag reader 100.

[0069] <4-2. Data selection process> In this section, several examples of data selection processes for selecting useful read results to be sent to the management server 200 from the read results iteratively added to the storage unit 112 through the read attempt process described above will be described.

[0070] (1) First Example 6 is an explanatory diagram of the selection of read results in the first embodiment. In the scenario of FIG. 6, a user 20 carrying an item 30 passes through the read range 105 of the tag reader 100 along a linear path indicated by an arrow A3. During this time, the reading unit 116 of the tag reader 100 detects the target tag 50 attached to the item 30 seven times. The control unit 111 selects seven read results D corresponding to the seven tag reads. 11 ~D 17 is temporarily stored in the storage unit 112.

[0071] In the first embodiment, the control unit 111 determines whether or not there are other read results associated with the same tag ID within a time window W1 (first time window) whose end point is the read time of each read result. In the example of FIG. 6, the read result D 11 There is no other read result associated with the same tag ID before the read time of D. Therefore, the control unit 111 11 is determined to be the first read result corresponding to the point in time when the article 30 entered the read range 105 of the tag reader 100. On the other hand, read result D 12 ~D 17 For each of the read results D, there are other read results associated with the same tag ID within the time window W1 ending at that read time. For example, for read result D, 14 Within the time window W1 ending at the reading time of 13 exists. Reading result D 17 Within the time window W1 ending at the reading time of 16 Therefore, the control unit 111 determines that the read result D 12 ~D 17 is determined not to be the first reading result corresponding to the entry time.

[0072] Furthermore, the control unit 111 determines whether or not there are other read results associated with the same tag ID within a time window W2 (second time window) starting from the read time of each read result. In the example of FIG. 6, the read result D 17There is no other read result associated with the same tag ID after the read time of D. Therefore, the control unit 111 17 is determined to be the second read result corresponding to the time when the article 30 left the read range 105 of the tag reader 100. On the other hand, read result D 11 ~D 16 For each of the read results D, there are other read results associated with the same tag ID within the time window W2 starting from the read time. For example, for read result D, 11 Within the time window W2 starting from the reading time of 12 exists. Reading result D 14 Within the time window W2 starting from the reading time of 15 Therefore, the control unit 111 determines that the read result D 11 ~D 16 is not the second reading result corresponding to the time of departure. The time window W2 may be equal to or different from the time window W1.

[0073] Based on these determinations, the control unit 111 outputs a series of read results D 11 ~D 17 Of these, reading result D 11 (First reading result) and reading result D 17 The control unit 111 selects the read result D (second read result) as a useful read result. 12 ~D 16 is deleted from the storage unit 112 without being transmitted to the management server 200.

[0074] 7 is a flowchart showing an example of the flow of the data selection process according to Example 1. The control unit 111 executes the data selection process at an execution cycle that is sufficiently longer than the reading cycle of the reading unit 116.

[0075] First, in S21, the control unit 111 focuses on one read result stored in the memory unit 112. In S22, the control unit 111 determines whether there are other read results associated with the tag ID of the same RFID tag within the time window W1 up to the read time of the focused read result. If it is determined in S22 that there are no other read results, the control unit 111 determines in S23 that the focused read result is a first read result corresponding to the entry time. For example, the control unit 111 assigns a flag to this read result indicating that it corresponds to the entry time. Then, the process proceeds to S29.

[0076] If it is determined in S22 that other read results exist, the process proceeds to S24. In S24, the control unit 111 determines whether other read results associated with the tag ID of the same RFID tag exist within a time window W2 from the read time of the focused read result. If it is determined in S24 that other read results do not exist, the control unit 111 determines in S25 that the focused read result is a second read result corresponding to the time of departure. For example, the control unit 111 assigns a flag to this read result indicating that it corresponds to the time of departure. Then, the process proceeds to S29.

[0077] If it is determined in S24 that other read results exist, the process proceeds to S28. In S28, the control unit 111 determines that the read result of interest is a redundant read result. For example, the control unit 111 assigns a flag to this read result indicating that it is a redundant read result. Then, the process proceeds to S29.

[0078] In S29, the control unit 111 determines whether any unprocessed read results remain in the memory unit 112. If any unprocessed read results remain, the process returns to S21, and S22 to S29 are repeated focusing on the next read result. If no unprocessed read results remain, the data selection process of FIG. 7 ends. The control unit 111 may delete from the memory unit 112 any read results determined to be redundant in S28 (or any read results determined not to correspond to the first read result or the second read result). Note that the expression "redundant" read results in this specification refers to read results other than the read results selected to be left in the memory unit 112, and does not question whether they are inherently redundant or not.

[0079] (2) First Example - Modification In a modification of the first embodiment, the control unit 111 may consider only the read results in which the received signal strength indicates a value greater than the reference value when determining whether each read result corresponds to an entry time or a departure time.

[0080] 8 is an explanatory diagram of the selection of the read result in this modified example. In the scenario of FIG. 8, similar to the scenario of FIG. 6, user 20 carrying item 30 passes through read range 105 of tag reader 100 along a straight path indicated by arrow A3. However, in FIG. 8, there are points within the boundary of read range 105 where the received signal strength (RSS) is equal to or greater than the reference value L REF The boundary of the area above this is shown by a dashed line. The area inside this boundary may be considered to be the effective read range 106.

[0081] In this modification, the control unit 111 ignores the read result in which the received signal strength is smaller than the reference value, and executes the above-described data selection process. In the example of FIG. 8, the read result D when the article 30 is located outside the effective read range 106 is 11 and D 17 is ignored. Therefore, the reading result D 12 is determined to be the first read result corresponding to the point in time when the article 30 entered the read range 105 of the tag reader 100. In other words, the read result D 12corresponds to the first read result in which the received signal strength exceeds the reference value among the read results that are periodically generated when the article 30 enters the read range 105 of the tag reader 100. Similarly, read result D 16 is determined to be the second read result corresponding to the time when the article 30 leaves the read range 105 of the tag reader 100. In other words, the read result D 16 corresponds to the last time the received signal strength exceeded the reference value among the read results that are periodically generated when the article 30 leaves the read range 105 of the tag reader 100.

[0082] Generally, near the boundary of the read range, RFID tags that are actually present tend to go undetected due to disturbances such as environmental noise or interference from other systems. This can lead to situations where the RFID tag is mistakenly recognized as frequently entering and leaving the read range. In contrast, by considering only read results in which the received signal strength is greater than a reference value, as in this modified example, the effects of disturbances can be eliminated, and the reliability of entry and exit detection can be improved.

[0083] (3) Second Example In the second embodiment, the control unit 111 selects a first read result corresponding to the time of entry and a second read result corresponding to the time of departure from read results corresponding to multiple tag ID reads from an RFID tag by the reading unit 116, according to the same selection conditions as in the first embodiment. Furthermore, when the tag ID is read one or more times from the same RFID tag during the period from the time of entry to the time of departure, the control unit 111 selects one third read result from the read results corresponding to the one or more reads every time a time length L1 (first time length) elapses. The time length L1 here is preset to a value longer than the read cycle of the reading unit 116. The control unit 111 selectively stores the first read result, the second read result, and the third read result in the memory unit 112.

[0084] 9 is an explanatory diagram of the selection of the read result in this embodiment. In the scenario of FIG. 9, similar to the scenario of FIG. 6, the user 20 carrying the item 30 passes through the read range 105 of the tag reader 100 along the linear path indicated by the arrow A3. During this time, the reading unit 116 of the tag reader 100 detects the target tag 50 attached to the item 30 seven times, and the control unit 111 selects the read result D. 11 ~D 17 is temporarily stored in the storage unit 112.

[0085] The control unit 111 receives the read result D 11 Based on the fact that there are no other reading results within the time window W1 ending at the reading time of 11 The control unit 111 selects the read result D as the first read result corresponding to the entry time. 17 Based on the fact that there are no other reading results within the time window W2 starting from the reading time of 17 is selected as the second reading result corresponding to the time of departure. In addition, the reading result D 15 If you look at the result, D 11 Reading result D from reading time 15 Therefore, in this embodiment, the control unit 111 determines that the read result D 15 as the third read result. Typically, the third read result is repeatedly selected at time intervals corresponding to the time length L1 while the item 30 is staying within the read range 105 of the tag reader 100. For example, the control unit 111 may measure the time length L1 from the most recent read time of the selected first read result and third read result, and select the read result having the first read time after the time length L1 has elapsed as the third read result. In the following description, the third read result will also be referred to as the "read result during stay." The time length L1 is set to a value greater than the time windows W1 and W2.

[0086] Based on these determinations, the control unit 111 outputs a series of read results D 11 ~D 17 Of these, reading result D 11 (First reading result), Reading result D15 (Third reading result) and reading result D 17 The control unit 111 selects the read result D (second read result) as a useful read result. 12 ~D 14 and D 16 is deleted from the storage unit 112 without being transmitted to the management server 200.

[0087] In this embodiment, the control unit 111 may include information indicating that the third read result, which has a read time intermediate between the time of entry into and the time of exit from the read range, is a read result obtained during the stay, so that the management server 200 that receives the third read result can easily distinguish the third read result from the first read result and the second read result described above.

[0088] 10 is a flowchart showing an example of the flow of the data selection process according to Example 2. The control unit 111 executes the data selection process at an execution cycle that is sufficiently longer than the reading cycle of the reading unit 116.

[0089] First, in S21, the control unit 111 focuses on one read result stored in the storage unit 112. The subsequent processes of S22 to S25 are the same as those described with reference to FIG. 7, and therefore, description thereof will be omitted here.

[0090] In S26, the control unit 111 determines whether a read result determined not to correspond to either the entry time or the exit time was output after the time length L1 has elapsed since the read time of the immediately preceding non-redundant read result. Here, a "non-redundant read result" may correspond to a read result corresponding to the entry time or a read result obtained during a stay. If the read result of interest was output after the time length L1 has elapsed, in S27 the control unit 111 determines that the read result of interest is a (useful) read result obtained during a stay. For example, the control unit 111 assigns a flag to this read result indicating that it is a read result obtained during a stay. Then, the process proceeds to S29.

[0091] If the read result focused on in S26 was output before the time length L1 has elapsed, the process proceeds to S28. In S28, the control unit 111 determines that the read result focused on is a redundant read result. For example, the control unit 111 assigns a flag to this read result indicating that it is a redundant read result. Then, the process proceeds to S29.

[0092] In S29, the control unit 111 determines whether any unprocessed read results remain in the storage unit 112. If any unprocessed read results remain, the process returns to S21, and S22 to S29 are repeated focusing on the next read result. If no unprocessed read results remain, the data selection process of FIG. 10 ends. The control unit 111 can delete from the storage unit 112 the read results that were determined to be redundant in S28.

[0093] As in this embodiment, in addition to the reading results corresponding to the time of entry and exit, by selecting the reading results during the stay selected at regular time intervals between those times as useful reading results, it is possible to leave a fairly detailed history of the location of the managed object as location information.

[0094] (4) Third Example The data selection process in the third embodiment targets the read results of RFID tags fixedly installed in real space. For example, the relative position of position tag 40b with respect to tag reader 100b shown in FIG. 1 does not change, and position tag 40b is always located within read range 105b of tag reader 100b. In this situation, tag reader 100b repeatedly detects position tag 40b at short intervals, generating a large amount of redundant read results. This embodiment is intended to reduce such redundant information.

[0095] In this embodiment, the control unit 111 does not need to perform entry detection and departure detection as in the first embodiment. When the tag ID is read from the RFID tag one or more times, the control unit 111 selects one fourth read result every time a time length L2 (second time length) has elapsed since the read results corresponding to the one or more reads. The time length L2 here is set in advance to a value longer than the read cycle of the reading unit 116. The control unit 111 selectively stores the fourth read result in the memory unit 112.

[0096] Selectively storing the fourth reading result in storage unit 112 may include discarding at least one reading result that does not correspond to the fourth reading result without storing it in storage unit 112. Alternatively, selectively storing the fourth reading result in storage unit 112 may include deleting at least one reading result that does not correspond to the fourth reading result from among the reading results temporarily stored in storage unit 112, from storage unit 112. In either case, the at least one reading result that is discarded or deleted is not transmitted to management server 200.

[0097] FIG. 11 is an explanatory diagram of the selection of a read result in the third embodiment. The horizontal axis of FIG. 11 is the time axis, and time progresses from left to right. The circles in the figure represent read results generated by tag reader 100, which is a fixed reader, for position tags 40 located within the read range of tag reader 100. Reader 116 of tag reader 100 starts up at time T=0, reads the tag ID of position tag 40, and outputs read result D. 20 After that, the reader 116 periodically reads the tag ID of the same position tag 40 and outputs the corresponding read results. These read results are temporarily stored in the memory 112.

[0098] The control unit 111 receives the read result D immediately after the reading unit 116 is started. 20 As a useful reading result, the control unit 111 selects one reading result as a useful reading result (fourth reading result) every time the time length L2 elapses. In the example of FIG. 11, every fifth reading result D 21 , D 22 , D23 , ... are selected, and the selected reading results are indicated by black circles. The control unit 111 deletes the reading results that are determined not to correspond to the fourth reading result from the storage unit 112 without transmitting them to the management server 200.

[0099] FIG. 12 is a flowchart showing an example of the flow of a data selection process according to the third embodiment.

[0100] First, in S41, the control unit 111 determines that the read result obtained immediately after the reading unit 116 is started is a useful read result. The control unit 111 assigns a flag to this read result indicating that it is a read result that should be transmitted to the management server 200.

[0101] Next, in S42, the control unit 111 waits until a preset length of time L2 has elapsed. After the length of time L2 has elapsed, in S43 the control unit 111 determines that the read result having the most recent read time among the read results output from the reading unit 116 during the length of time L2 is a useful read result. The control unit 111 assigns a flag to this read result indicating that it is a read result that should be sent to the management server 200. Next, in S44, the control unit 111 determines that the other read results among the read results output from the reading unit 116 during the length of time L2 are redundant read results. The control unit 111 assigns flags to these read results indicating that they are redundant read results.

[0102] The control unit 111 may transmit the reading results selected as useful in S41 and S43 to the management server 200. On the other hand, the control unit 111 does not transmit the reading results determined to be redundant in S44 to the management server 200. These reading results may be deleted from the storage unit 112. Thereafter, the process returns to S42, and the process is repeated for the next time length L2.

[0103] This embodiment may be combined with the first or second embodiment. For example, the control unit 111 selects first, second, and third read results from read results related to a first wireless device that may correspond to the target tag 30, while selecting a fourth read result from read results related to a second wireless device that may correspond to the position tag 40. The control unit 111 then transmits the first, second, third, and fourth read results to the management server 200, and deletes the other read results from the storage unit 112 without transmitting them to the management server 200. In such a combination, the time length L2, which is the time interval for selecting the read results of the position tag 40, may be set to a value greater than the time length L1, which is the time interval for selecting the read results of the target tag 50. Since the position tag 40 is generally assumed not to move, providing a difference between the time lengths L1 and L2 in this manner makes it possible to sufficiently reduce redundant information while maintaining the tracking performance of the position of a mobile management target.

[0104] (5) Third Example - Modified Example In a modification of the third embodiment, the control unit 111 determines that an RFID tag is fixedly installed in real space based on the fact that the number of times the tag ID of the RFID tag is read by the reading unit 116 within a predetermined period (referred to as a determination period) reaches a predetermined threshold. After this determination, the control unit 111 selects one fourth read result every time a second time length elapses from the read results corresponding to one or more reads of the tag ID from the RFID tag.

[0105] 13 is an explanatory diagram of the selection of the read result in this modified example. Here, the determination period during which the number of times the tag ID is read is counted is a time length L init The horizontal axis of FIG. 13 is the time axis, and time progresses from left to right. The reading unit 116 of the tag reader 100 starts up at time T=0. The control unit 111 outputs the read result D immediately after the reading unit 116 starts up. 30 As a useful reading result, the control unit 111 selects the time T=L initThe number of read results showing the tag ID of the same RFID tag is counted over the determination period until the tag ID of the same RFID tag is reached. 30 Read result D 31 Up to N DT The control unit 111 determines the number N of read results. DT is equal to or greater than a predetermined threshold, the control unit 111 determines that this RFID tag is a tag that is fixedly installed in real space. The control unit 111 may determine that this RFID tag is a position tag 40. Thereafter, the reading unit 116 continues to read the tag ID of the same RFID tag. In response to the above determination, the control unit 111 starts a data selection process similar to that of the third embodiment. That is, the control unit 111 selects one reading result as a useful reading result (fourth reading result) every time the second time length elapses. Reading result D 31 13, the second time length is equal to L2a, and the read result D is selected by the control unit 111 as a useful read result. 32 , D 33 , . . . are indicated by black circles. The control unit 111 deletes from the storage unit 112 the read result that is determined not to be the fourth read result without transmitting it to the management server 200.

[0106] According to this modification, tag reader 100 can apply data selection processing appropriate for the type of each detected RFID tag, even if it does not have prior knowledge of the type of each individual RFID tag. For example, assume that a fixed reader is installed near position tag 40. The fixed reader recognizes that position tag 40, which has been located nearby since its installation, will not move, and transmits the tag ID read results of that tag to management server 200 at longer time intervals. Meanwhile, the fixed reader transmits the tag ID read results of target tags 50 attached to articles 30 passing through its reading range to management server 200 at shorter time intervals. In this modification, the fixed reader does not need to know in advance that the RFID tags present in the vicinity are position tags 40.

[0107] In this modification, an example has been described in which a determination that a wireless device is fixedly installed in real space is made based on the number of times information is read from the wireless device, but a similar determination may be made using a different method. For example, the control unit 111 may inquire of the management server 200 about the type of the detected RFID tag (position tag 40 or target tag 50) and determine the type of RFID tag based on a response from the management server 200. Alternatively, the control unit 111 may download a list of position tags 40 stored in the position tag table 320 from the management server 200 and determine whether the detected RFID tag is a position tag 40 based on the downloaded list.

[0108] (6) Fourth Example The data selection process in the fourth embodiment targets read results generated by a mobile reader moving in real space. In this embodiment, the mobile reader has a measurement unit 114 that measures the amount of relative movement using a self-location estimation technique. For example, the tag reader 100a shown in FIG. 1 moves while measuring the amount of relative movement and detects RFID tags that enter the read range 105a. However, the tag reader 100a is not always moving. The reading unit 116 may repeatedly detect RFID tags even when the tag reader 100a is stationary. This embodiment is intended to reduce redundant read results during periods when the mobile reader is substantially stationary.

[0109] Specifically, in this embodiment, the control unit 111 selects first and second read results corresponding to the time of entry and the time of exit from read results corresponding to multiple readings of the tag ID from the RFID tag by the reading unit 116, in accordance with the same selection conditions as in the first embodiment. Furthermore, when the tag ID is read from the same RFID tag one or more times during the period from the time of entry to the time of exit, the control unit 111 selects a third read result based on the change in the amount of relative movement measured by the measurement unit 114. The control unit 111 transmits the first, second, and third read results to the management server 200, while deleting the other read results from the storage unit 112 without transmitting them to the management server 200.

[0110] 14 is an explanatory diagram of the selection of the read result in this embodiment. In the scenario of FIG. 14, user 20 carrying tag reader 100 moves along the route indicated by arrow A4. Reader 116 of tag reader 100 detects position tag 40 at times T1 and T2 and outputs read result D. 41 and D 42 to the control unit 111. The reading unit 116 also detects the target tag 50 attached to the article 30 at times T3, T4, T5, T6, T7, and T8, and outputs the reading result D 43 , D 44 , D 45 , D 46 , D 47 and D 48 to the control unit 111. However, from time T3 to T4, the tag reader 100 is substantially stationary, and the amount of relative movement measured by the measurement unit 114 changes only slightly during this period. Similarly, from time T5 to T7, the tag reader 100 is substantially stationary, and the amount of relative movement measured by the measurement unit 114 changes only slightly during this period. The control unit 111, for example, compares the amount of change in the amount of relative movement measured by the measurement unit 114 at each reading time with a predetermined threshold. The amount of change here may be the difference in the amount of relative movement from the previously selected first or third reading result. Then, only when the amount of change exceeds the threshold, the control unit 111 selects the corresponding reading result as the third reading result. In the example of FIG. 14, focusing on the reading result for the target tag 50, the first reading result D corresponding to the time of entry 43 and the second reading result D corresponding to the time of departure 48 In addition, the reading result D where the change in the relative movement amount exceeds the threshold 45 is selected as the third reading result. The control unit 111 43 , D 45 and D 48 to the management server 200. On the other hand, if the read result D does not correspond to any of the first, second, and third read results, 44 , D 46 and D 47 is deleted from the storage unit 112 without being sent to the management server 200.

[0111] As in this embodiment, by selecting, as the read result during stay, not only the read results corresponding to the entry and exit times, but also the read results at times when the mobile reader moved significantly between those times, it is possible to reduce redundant information and manage precise location information at the same time. Note that, if the measurement unit 114 can recognize the walking steps of the user 20 carrying the tag reader 100, the control unit 111 may select, as the third read result, the read result at the time when the walking steps were recognized, instead of the time when the amount of change in the amount of relative movement exceeded the threshold.

[0112] (7) Fifth Example In the fifth embodiment, the tag reader 100 communicates with the management server 200 via a relay device. The communication connection between the tag reader 100 and the relay device is not always valid, and there are periods during which the tag reader 100 cannot communicate with the relay device, depending on conditions such as operational agreements, the relative positions of the tag reader 100 and the relay device, or the power status of the relay device. The reading unit 116 of the tag reader 100 may repeatedly detect RFID tags even during periods during which the communication connection is not valid. This embodiment is intended to reduce the amount of read result data resulting from reading tag IDs during such periods when the communication connection is not valid.

[0113] FIG. 15 is an explanatory diagram of an example of communication from the tag reader 100 to the management server 200 via a relay device. Referring to FIG. 15, a relay device 300 is installed in a real space 10. The relay device 300 may be, for example, a general-purpose computer such as a smartphone, tablet PC (Personal Computer), or laptop PC equipped with a Bluetooth (registered trademark) communication module. The relay device 300 may be either a portable type or a stationary type. The communication unit 113 of the tag reader 100 is a Bluetooth slave device.

[0114] The tag reader 100 is carried by the user 20 and moves within the real space 10. When a position tag 40 enters the reading range 105 of the tag reader 100, the reading unit 116 of the tag reader 100 reads the tag ID of the position tag 40 and outputs the reading result (arrow C1 in the figure). Similarly, when a target tag 50 enters the reading range 105 of the tag reader 100, the reading unit 116 reads the tag ID of the target tag 50 and outputs the reading result (arrow C2 in the figure). In reality, the tag ID is read periodically multiple times, and reading results corresponding to these multiple readings are generated. When the tag ID is read multiple times from the position tag 40, the control unit 111 selectively stores one fourth reading result from the reading results corresponding to the multiple readings in the memory unit 112 every time the above-mentioned time length L2 elapses.

[0115] When tag reader 100 approaches relay device 300, communication unit 113 of tag reader 100 establishes a communication connection with the communication module of relay device 300. Control unit 111 uses this communication connection to transmit the read results stored in memory unit 112 to relay device 300 (arrow C3 in the figure). Relay device 300 temporarily stores the read results received from tag reader 100 in its internal memory, and then relays them to management server 200 (arrow C4 in the figure). Note that the communication connection between tag reader 100 and relay device 300 is not limited to the example given here, and may be a connection via WLAN or wireless USB, for example.

[0116] When the communication connection between communication unit 113 and relay device 300 is valid, control unit 111 sets time length L2 to a first value. When the transmission of the fourth reading result to relay device 300 is completed, control unit 111 deletes the fourth reading result from storage unit 112. On the other hand, when the communication connection between communication unit 113 and relay device 300 is not valid, control unit 111 sets time length L2 to a second value greater than the first value.

[0117] FIG. 16 is an explanatory diagram of the selection of read results in this embodiment. The horizontal axis of FIG. 16 is the time axis, and time progresses from left to right. The reading unit 116 of the tag reader 100 repeatedly reads tag IDs from position tags 40 within the reading range 105 and outputs a large number of read results. The communication connection between the communication unit 113 and the relay device 300 is established at time T=T 10 During this time, the control unit 111 selects one read result as the fourth read result every time the time length L2 elapses, and deletes the read results that do not correspond to the fourth read result from the storage unit 112. In the example of FIG. 16, the read result D selected as the fourth read result is 51 and D 52 These reading results D 51 and D 52 is transmitted to the relay device 300 via the active communication connection.

[0118] The communication connection between the communication unit 113 and the relay device 300 is established at time T=T 10 The read result is cut off at . Then, the control unit 111 changes the value of the time length L2 from the previous first value to a larger second value. The changed time length is designated as L2'. The control unit 111 selects one read result as the fourth read result every time the time length L2' elapses, and deletes the read results that do not correspond to the fourth read result from the storage unit 112. In the example of FIG. 16, the read result D selected as the fourth read result is 53 is indicated by a black circle. Reading result D 53 is transmitted to the relay device 300 after the communication connection between the communication unit 113 and the relay device 300 is resumed.

[0119] In this embodiment, by setting the time length L2' to be sufficiently longer than the time length L2, it is possible to suppress the amount of read results accumulated during the period when the communication connection between the communication unit 113 and the relay device 300 is not active, thereby avoiding exhaustion of memory resources of the tag reader 100. In particular, by applying the data selection process according to this embodiment to the read results of the position tag 40 rather than the target tag 50, it is possible to significantly reduce redundant position information for the position tag 40 that does not move, while maintaining precise position tracking of the article 30 that may move.

[0120] Note that the selection of read results over a relatively long time period during a communication unavailable period described in this embodiment may be applied to the target tag 50. That is, the control unit 111 may set the time length L1 (see the second embodiment) for selecting the third read result to a first value when the communication connection is valid, and may set the time length L1 to a second value greater than the first value when the communication connection is invalid. This makes it possible to further reduce the amount of read results accumulated during a period when the communication connection is invalid.

[0121] The various embodiments and modifications of the data selection process described above may be combined in any manner. For example, in the second to fifth embodiments, as in the modification of the first embodiment, only reading results that show a received signal strength that exceeds a reference value may be considered in the data selection process.

[0122] <4-3. Location estimation processing> 17 is a flowchart showing an example of the flow of the position estimation process executed by the management server 200 based on the read result data selected by the tag reader 100 and transmitted to the management server 200. It is assumed that several tag detection records have been accumulated in the tag detection table 340 at the time the position estimation process of FIG.

[0123] First, in S111, the data management unit 231 of the management server 200 acquires one tag detection record. The subsequent processing branches in S112 depending on whether the acquired tag detection record is a record for the target tag 50 or a record for the position tag 40. If the tag detection record is a record for the position tag 40, the processing proceeds to S113. On the other hand, if the tag detection record is a record for the target tag 50, the processing proceeds to S114.

[0124] In S113, the monitoring unit 233 updates the corresponding record in the position tag monitoring table 360 ​​based on the result of reading the tag ID from the position tag 40 indicated by the tag detection record acquired in S111.

[0125] Meanwhile, in S114, the estimation unit 232 extracts from the tag detection table 340 tag detection records for one or more position tags 40 received from the same tag reader 100 as the tag detection record acquired in S111. Then, in S115, the estimation unit 232 selects one reference position tag to be used as a reference for position estimation based on the correlation between the tag detection record for the target tag 50 and the tag detection records for one or more position tags 40. For example, the estimation unit 232 may select as the reference position tag the position tag 40 detected at the time closest to the reading time of the tag ID of the target tag 50. Then, in S116, the estimation unit 232 estimates that the item 30 to which the target tag 50 is attached is located near the installation location of the selected reference position tag.

[0126] The subsequent steps S117 and S118 are optional processing steps that are executed when the tag reader 100 that detected the target tag 50 has a movement amount measurement function. In S117, the estimation unit 232 calculates the relative movement amount of the tag reader 100 from the time the reference position tag is read to the time the target tag 50 is read. The calculated relative movement amount may correspond to the difference between the relative movement amounts indicated by the two corresponding tag detection records. Next, in S118, the estimation unit 232 estimates the position coordinates of the item 30 to which the target tag 50 is attached based on the calculated relative movement amount and the known position of the reference position tag. For example, the position coordinates of the item 30 may be the sum of the relative movement amount calculated in S117 and the position coordinates of the installation position of the reference position tag.

[0127] Next, in S119, the estimation unit 232 adds an estimation result record based on the estimation result in S116 (and S118) to the item history table 350. For example, the estimation result in S116 is reflected in the location ID 354 in the item history table 350, and the estimation result in S118 is reflected in the estimated location 355 in the item history table 350.

[0128] Management server 200 may repeat the above-described location estimation process for each tag detection record added to tag detection table 340. This allows location information for each item 30 to be updated as needed based on read result data from one or more tag readers 100, and constantly monitors the operating status of each position tag 40. Although not shown in FIG. 17 , information provider 234 provides such information maintained in location information DB 220 to user 20 in any format.

[0129] <5. Other embodiments> The above-described embodiment can also be realized in the form of a process in which a program for realizing one or more functions is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program, or by a circuit (e.g., ASIC) that realizes one or more functions.

[0130] The disclosure of the present specification includes at least the following reading device and information providing system. (Item 1) reading means for periodically attempting to read information from a wireless device within a reading range; a storage means; a control means for storing, when the reading means reads first identification information from the first wireless device, a read result indicating at least the first identification information and a read time of the first identification information in the storage means; Equipped with when the first identification information is read from the first wireless device a plurality of times, the control means selectively stores in the storage means a first read result corresponding to the entry time point when the first wireless device enters the read range and a second read result corresponding to the exit time point when the first wireless device leaves the read range from the read results corresponding to the plurality of times of reading; Selectively storing the first read result and the second read result in the storage means includes: Not storing at least one read result that does not correspond to the first read result and the second read result in the storage means; and deleting at least one read result that does not correspond to the first read result or the second read result from among the read results temporarily stored in the storage means; at least one of Reading device. (Item 2) the reading device further comprises a communication means for communicating with an external device; the control means transmits the first read result and the second read result read from the storage means to the external device via the communication means; Item 1. A reading device according to item 1. (Item 3) Item 3. The reading device according to item 2, wherein the control means includes, in each reading result transmitted to the external device, information indicating that the reading result corresponds to the entry time or that the reading result corresponds to the exit time. (Item 4) The reading device according to any one of items 1 to 3, wherein the control means determines that the first reading result corresponds to the entry time point based on the absence of other reading results associated with the first identification information within a first time window ending at the reading time of the first reading result. (Item 5) The reading device described in item 4, wherein the control means determines that the second reading result corresponds to the time of departure based on the absence of other reading results associated with the first identification information within a second time window starting from the reading time of the second reading result. (Item 6) the reading means measures a received signal strength of a signal received from a wireless device; each reading result further indicates the received signal strength measured by the reading means; the control means, when determining whether each reading result corresponds to the entry time point or the departure time point, considers only reading results in which the received signal strength indicates a value greater than a reference value; Item 6. A reading device according to item 4 or 5. (Item 7) The reading device according to any one of items 1 to 6, wherein when the first identification information is read from the first wireless device one or more times during the period from the time of entry to the time of departure, the control means further stores one third reading result in the storage means every time a first length of time elapses from the reading result corresponding to the one or more readings. (Item 8) the reading device further comprises a communication means for communicating with an external device; The control means setting the first time length to a first value when a communication connection between the communication means and the external device is valid; setting the first time length to a second value greater than the first value when a communication connection between the communication means and the external device is not active; transmitting the first read result, the second read result, and the third read result read from the storage means to the external device via the communication means while the communication connection between the communication means and the external device is active; Item 7. A reading device according to item 7. (Item 9) The reading device a measuring means for measuring the relative movement of the reading device; Furthermore, the control means further stores in the storage means a third reading result selected based on the change in the amount of relative movement during the period from the time point of entry to the time point of departure. The reading device according to any one of items 1 to 6. (Item 10) 10. The reader according to any one of items 1 to 9, wherein the first wireless device is attached to a managed object that is movable in real space. (Item 11) Item 11. The reading device according to item 10, wherein when the second identification information is read multiple times by the reading means from a second wireless device fixedly installed in the real space, the control means selectively stores one fourth reading result in the storage means each time a second time length has elapsed since the reading results corresponding to the multiple readings. (Item 12) The reading device described in item 11, wherein the control means determines that a wireless device is the second wireless device that is fixedly installed based on the number of times that the identification information of the wireless device is read by the reading means within a predetermined period of time reaching a predetermined threshold. (Item 13) Item 13. The reading device according to item 12, wherein the predetermined period is a period from when the reading means is started until a third length of time has elapsed. (Item 14) the reading device further comprises a communication means for communicating with an external device; The control means setting the second length of time to a first value when a communication connection between the communication means and the external device is active; setting the second time length to a second value greater than the first value when a communication connection between the communication means and the external device is not active; transmitting the fourth read result read from the storage means to the external device via the communication means while the communication connection between the communication means and the external device is active; The reading device according to any one of items 11 to 13. (Item 15) 15. The reader according to any one of items 1 to 14, wherein the wireless device is an RFID (Radio Frequency Identification) tag. (Item 16) A reading device according to any one of items 1 to 15, an information processing device that receives the first reading result and the second reading result from the reading device; An information providing system including: the information processing device provides a user with location information based on the first reading result and the second reading result. Information provision system.

[0131] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0132] 1: Information providing system, 5: Network, 10: Real space, 20 (20a, 20b): User, 30 (30a, 30b): Item (managed object), 40 (40a, 40b, 40c): Location tag (second wireless device), 50 (50a, 50b): Target tag (first wireless device), 100 (100a, 100b, 100c): Tag reader (reading device), 105 (105a, 105b, 105c): Reader Range, 111: control unit (control means), 112: memory unit (memory means), 113: communication unit (communication means), 114: measurement unit (measurement means), 116: reading unit (reading means), 160: terminal device, 200: management server (information processing device / external device), 210: communication unit, 220: location information DB, 231: data management unit, 232: estimation unit, 233: monitoring unit, 234: information provision unit, 300: relay device (external device)

Claims

1. reading means for periodically attempting to read information from a wireless device within a reading range; a storage means; a control means for causing the storage means to store, when the reading means reads first identification information from the first wireless device, at least the first identification information and a read result indicating the time when the first identification information was read; Equipped with when the first identification information is read from the first wireless device a plurality of times, the control means selectively stores in the storage means a first read result corresponding to the entry time point when the first wireless device enters the read range and a second read result corresponding to the exit time point when the first wireless device leaves the read range from the read results corresponding to the plurality of reads; Selectively storing the first reading result and the second reading result in the storage means includes: Not storing at least one read result that does not correspond to the first read result and the second read result in the storage means; and deleting from the storage means at least one read result that does not correspond to the first read result or the second read result among the read results temporarily stored in the storage means; at least one of Reading device.

2. the reading device further comprises a communication means for communicating with an external device; the control means transmits the first read result and the second read result read from the storage means to the external device via the communication means; The reading device according to claim 1 .

3. The reading device according to claim 2, wherein the control means includes information in each reading result transmitted to the external device indicating that the reading result corresponds to the entry time or that the reading result corresponds to the exit time.

4. 2. The reading device according to claim 1, wherein the control means determines that the first reading result corresponds to the entry time point based on the absence of other reading results associated with the first identification information within a first time window ending at the reading time of the first reading result.

5. The reading device according to claim 4, wherein the control means determines that the second reading result corresponds to the time of departure based on the absence of other reading results associated with the first identification information within a second time window starting from the reading time of the second reading result.

6. the reading means measures a received signal strength of a signal received from a wireless device; each reading result further indicates the received signal strength measured by the reading means; the control means, when determining whether each reading result corresponds to the entry time point or the departure time point, considers only reading results in which the received signal strength indicates a value greater than a reference value; 5. The reading device according to claim 4.

7. The reading device described in claim 1, wherein when the first identification information is read from the first wireless device one or more times during the period from the time of entry to the time of exit, the control means further stores one third reading result in the memory means every time a first length of time elapses from the reading result corresponding to the one or more readings.

8. the reading device further comprises a communication means for communicating with an external device; The control means setting the first time length to a first value when a communication connection between the communication means and the external device is active; setting the first time length to a second value greater than the first value when a communication connection between the communication means and the external device is not active; transmitting the first read result, the second read result, and the third read result read from the storage means to the external device via the communication means while the communication connection between the communication means and the external device is active; 8. The reading device according to claim 7.

9. The reading device is a measuring means for measuring the relative movement of the reading device; Furthermore, the control means further stores in the storage means a third reading result selected based on the change in the amount of relative movement during the period from the time point of entry to the time point of departure. The reading device according to claim 1 .

10. The reader according to claim 1 , wherein the first wireless device is attached to a management object that is movable in real space.

11. The reading device described in claim 10, wherein when the reading means reads second identification information multiple times from a second wireless device fixedly installed in the real space, the control means selectively stores one fourth reading result in the memory means each time a second time length elapses from the reading results corresponding to the multiple readings.

12. The reading device according to claim 11, wherein the control means determines that a wireless device is the second wireless device that is fixedly installed based on the number of times that the identification information of the wireless device is read by the reading means within a predetermined period of time reaching a predetermined threshold.

13. 13. The reading device according to claim 12, wherein the predetermined period is a period from when the reading means is activated until a third length of time has elapsed.

14. the reading device further comprises a communication means for communicating with an external device; The control means setting the second length of time to a first value when a communication connection between the communication means and the external device is active; setting the second time length to a second value greater than the first value when a communication connection between the communication means and the external device is not active; transmitting the fourth read result read from the storage means to the external device via the communication means while the communication connection between the communication means and the external device is active; The reading device according to claim 11.

15. The reader according to claim 1 , wherein the wireless device is an RFID (Radio Frequency Identification) tag.

16. A reading device according to any one of claims 1 to 15; an information processing device that receives the first reading result and the second reading result from the reading device; An information providing system including: the information processing device provides a user with location information based on the first reading result and the second reading result. Information provision system.

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