JP7267797B2 - Reading device and reading system - Google Patents

Description

Embodiments of the present invention relate to reading devices and reading systems.

A self-propelled reader that reads information from a wireless tag such as an RF (radio frequency) tag attached to an article is known. Such a reader may fail to read information when the distance between wireless tags is narrow.

U.S. Patent Application Publication No. 2016/0239021

The problem to be solved by the embodiments of the present invention is to provide a reading device and a reading system that reduce the possibility of missing information from wireless tags.

A reader of an embodiment comprises a mobile device, an antenna and a controller. The mobile device moves the mobile object. The antenna is provided on the mobile body and receives radio waves transmitted from the wireless tag. The control unit performs a first reading operation and a second reading operation. In the first reading operation, information stored in the wireless tag within a predetermined range is read using the antenna while moving the mobile body. A second reading operation is performed as follows when the reading rate of reading information from the wireless tags in the range by the first reading operation is equal to or less than a threshold value. In the second reading operation, the distance between the antenna and the wireless tag is made shorter than the distance between the antenna and the wireless tag in the first reading operation, and the antenna is read while moving the moving body. to read the information stored in the RFID tag in the range.

1 is a diagram showing an example of the configuration of a reading system according to an embodiment; FIG. 1 is a block diagram showing an example of the configuration of a reading system according to an embodiment; FIG. The figure which shows an example of a structure of the work instruction information which concerns on embodiment. The figure which shows an example of a structure of the shelf information which concerns on embodiment. The figure which shows an example of the shelf information which concerns on embodiment. The figure which shows an example of a structure of the goods information which concerns on embodiment. 4 is a diagram showing an example of the configuration of reading distance instruction information according to the embodiment; FIG. FIG. 4 is a diagram showing an example of the configuration of reading result information according to the embodiment; FIG. 3 is a flowchart showing an example of processing by a processor 11 in FIG. 2; FIG. FIG. 3 is a flowchart showing an example of processing by a processor 11 in FIG. 2; FIG. FIG. 3 is a flowchart showing an example of processing by a processor 11 in FIG. 2; FIG.

A reading system according to an embodiment will be described below with reference to the drawings. It should be noted that the scale of each part of each drawing used for the description of the following embodiments may be changed as appropriate. Also, in each drawing used for the description of the embodiments below, the configuration may be omitted for the sake of description. Also, in each drawing and the following description, the same reference numerals denote similar elements.

FIG. 1 is a diagram showing an example of the configuration of a reading system 1 according to an embodiment. The reading system 1 is an example of a reading device. The reading system 1 is a system that reads a plurality of wireless tags in an area where a plurality of wireless tags exist. For example, the reading system 1 is used for inventory of articles in a store having a plurality of shelves. Here, one shelf A out of the plurality of shelves will be described as an example. Since the shelves other than shelf A are configured in the same manner as shelf A, the description thereof is omitted.

Each shelf is configured with a width of a predetermined length extending in one direction. The direction in which each shelf extends is called the first direction. Shelf A stores a plurality of articles. A plurality of items are displayed on shelf A along a first direction. The article 300 is one of a plurality of articles stored in a predetermined area of the shelf A. FIG. A wireless tag 301 is attached to the article 300 . For example, the wireless tag 301 is an RFID (radio frequency identifier). Articles other than the article 300 stored on the shelf A are also attached with wireless tags similar to the wireless tag 301 .

The wireless tag 301 wirelessly transmits/receives data to/from at least one of antennas 104a to 104d, which will be described later. The wireless tag 301 is wirelessly powered and activated by at least one of the antennas 104a-104d. The wireless tag 301 returns tag information including an identifier that uniquely identifies itself in response to a request through at least one of the antennas 104a-104d. The tag information is also called read result. The identifier of the wireless tag 301 will be described later.

The reading system 1 is composed of a system controller 10, a self-propelled robot 100, and the like. The system controller 10 and the self-propelled robot 100 are communicably connected to each other.

A system controller 10 controls the entire reading system 1 . The system controller 10 controls movement of the self-propelled robot 100 and reading of the wireless tag 301 . The system controller 10 will be described later.

The self-propelled robot 100 is self-propelled under the control of the system controller 10 . The self-propelled robot runs in front of the shelf A parallel or substantially parallel to the shelf A along the first direction. Self-propelled robot 100 is an example of a mobile object.

As shown in FIG. 1, the self-propelled robot 100 has a housing 101, wheels 102, a sensor 103, antennas 104a to 104d, and the like.

A housing 101 forms an outer shell of the self-propelled robot 100 . Wheels 102, sensors 103, and antennas 104a to 104d are attached to the housing 101. As shown in FIG.

Wheels 102 are attached to the bottom of housing 101 . The wheels 102 are driven by a motor 202 (to be described later) to move the housing 101 . Also, the wheels 102 change the direction of the housing 101 .

A sensor 103 is formed on the front surface of the self-propelled robot 100 . A sensor 103 is a sensor for detecting surrounding obstacles. The sensor 103 detects obstacles in the traveling direction of the self-propelled robot 100 . For example, the sensor 103 is composed of radar or the like.

The antennas 104a to 104d are formed in order from the upper part of the housing 101 downward.
Antennas 104a to 104d are formed on the side surface of the housing 101 so as to face the shelf A. As shown in FIG. Here, antennas 104a to 104d are formed on the left side with respect to the traveling direction of self-propelled robot 100. FIG.

Antenna 104a will be described. The antenna 104a is a device that wirelessly transmits and receives data to and from the wireless tag 301 attached to the article 300 . The antenna 104 a receives radio waves from the wireless tag 301 . Also, the antenna 104 a transmits radio waves to the wireless tag 301 . For example, the antenna 104a may be directional. A detection range in which radio waves can be transmitted and received is set according to the characteristics (such as directivity) and installation orientation of the antenna 104a. The detection range of the antenna 104a is set so that the wireless tag 301 of the article 300 on the shelf A can be read.
The configurations of the antennas 104b, 104c, and 104d are the same as that of the antenna 104a, so description thereof is omitted. The sum of the sensing ranges of antennas 104a-104d is set to encompass shelf A from top to bottom. Hereinafter, the antenna 104 may be simply used to refer to at least one of the antennas 104a-104d. Alternatively, the antennas 104 a to 104 d may be collectively referred to simply as the antenna 104 .

The number and positions of the antennas 104 included in the self-propelled robot 100 are not limited to a specific configuration. For example, the self-propelled robot 100 may have one antenna 104 with a detection range that covers the shelf A from the top end to the bottom end.

FIG. 2 is a block diagram showing an example of the configuration of the reading system 1 according to the embodiment. As shown in FIG. 2, the system controller 10 includes a processor 11, a ROM (read-only memory) 12, a RAM (random-access memory) 13, a NVM (non-volatile memory) 14, a communication unit 15, and the like. The processor 11, ROM 12, RAM 13, NVM 14, and communication unit 15 are connected to each other via a data bus or the like. The system controller 10 is an example of a control device.

The processor 11 has a function of controlling the operation of the system controller 10 as a whole. For example, the processor 11 is a CPU (central processing unit). Processor 11 is an example of a control unit. The processor 11 may include an internal memory, various interfaces, and the like. The processor 11 implements various processes by executing programs pre-stored in the internal memory, ROM 12, NVM 14, or the like.

Note that some of the various functions realized by the processor 11 executing the program may be realized by hardware circuits. In this case, processor 11 controls the functions performed by the hardware circuits.

The ROM 12 is a non-volatile memory that stores control programs and control data in advance. The ROM 12 is incorporated in the system controller 10 in a state in which control programs, control data, and the like are stored in the manufacturing stage. That is, the control program and control data stored in the ROM 12 are incorporated in advance according to the specifications of the system controller 10 .

RAM 13 is a volatile memory. The RAM 13 temporarily stores data being processed by the processor 11 . RAM 13 stores various application programs based on instructions from processor 11 . Also, the RAM 13 may store data necessary for executing the application program, execution results of the application program, and the like.

The NVM 14 is a non-volatile memory in which data can be written and rewritten. For example, the NVM 14 is composed of a HDD (hard disk drive), SSD (solid state drive), EEPROM (electric erasable programmable read-only memory), flash memory, or the like. The NVM 14 stores control programs, applications, various data, etc. according to the operational use of the system controller 10 . The NVM 14 is an example of a storage unit.

The NVM 14 stores work instruction information, shelf information, article information, reading distance instruction information, reading result information, and the like. Work instruction information, shelf information, article information, reading distance instruction information, and reading result information will be described later.

The communication unit 15 is an interface for transmitting and receiving data to and from the self-propelled robot 100 . The communication unit 15 transmits and receives data to and from the self-propelled robot 100 by wire or wirelessly. For example, the communication unit 15 is an interface that supports connection such as a LAN (local area network) or the Internet.

As shown in FIG. 2, the self-propelled robot 100 includes a sensor 103, antennas 104a-104d, a moving mechanism 200, a reader 210, and the like. Sensor 103 and antennas 104a-104d are as described above.

The moving mechanism 200 is a mechanism for moving the self-propelled robot 100 . The moving mechanism 200 is an example of a moving device that moves the self-propelled robot 100 . The moving mechanism 200 includes wheels 102, a travel controller 201, a motor 202, a rotary encoder 203, and the like. The travel controller 201 is electrically connected to the motor 202 and the rotary encoder 203 . Wheel 102 and motor 202 are physically connected. The wheels 102 are as previously described.

The travel controller 201 moves the self-propelled robot 100 under the control of the system controller 10 . The travel controller 201 controls the motor 202 and the like to move the self-propelled robot 100 . For example, the travel controller 201 supplies electric power, pulses, or the like to the motor 202 .

Motor 202 is driven under the control of travel controller 201 . The motor 202 connects to the wheels 102 via gears, belts, or the like. The motor 202 rotates the wheel 102 by its own driving force.

A rotary encoder 203 is connected to the rotating shaft of the motor 202 . A rotary encoder 203 measures the rotation angle of the motor 202 . The rotary encoder 203 transmits the measured rotation angle to the system controller 10 . Note that the rotary encoder 203 may be built in the motor 202 .

The reader 210 is an interface for wirelessly transmitting and receiving data to and from the wireless tags through the antennas 104a-104d. The reader 210 reads the tag information of the wireless tag by data communication with the wireless tag. For example, the reader 210 transmits a predetermined read command to the wireless tag under the control of the system controller 10. FIG. The reader 210 receives tag information as a response to the read command. The reader 210 transmits the received tag information to the system controller 10 .

Note that the reading system 1 may have a configuration other than the configuration shown in FIGS. 1 and 2 as necessary, or a specific configuration may be excluded from the reading system 1 .

Next, work instruction information will be described. The work instruction information is information for instructing inventory work. That is, the work instruction information instructs the system controller 10 to read a plurality of wireless tags using the self-propelled robot 100 . Here, the work instruction information indicates one or more shelves from which the reading system 1 reads multiple wireless tags.

FIG. 3 is a diagram showing an example of the configuration of work instruction information. As shown in FIG. 3, the work instruction information includes, for example, "work number", "work content", "shelf number", and "shelf number".
"Work number" indicates a number that uniquely identifies the work indicated by the work instruction information.
“Work content” indicates the work that the reading system 1 performs. Here, the "work content" is an inventory.
The "number of shelves" is the number of shelves for which work is instructed. In other words, the "number of shelves" is the number of shelves on which articles with wireless tags to be read are displayed.
The "shelf number" indicates the shelf on which the article with the wireless tag to be read is displayed. Here, the "shelf number" indicates the shelf by alphabet. Further, the work instruction information associates the "shelf number" with the "serial number". "Serial number" is a number indicating the order of work. Indicates that work is performed in order from the highest serial number. As an example, FIG. 3 shows that work is performed in the order of BFEA, starting with shelf number B with serial number 4 .

The work instruction information is stored in the NVM 14 by an operator or the like. The processor 11 may also receive work instruction information from an external device and store it in the NVM 14 . Also, the work instruction information may be updated as appropriate.
Note that the configuration of the work instruction information is not limited to a specific configuration.

Next, shelf information will be described. Shelf information is information about each shelf. For example, the shelf information is information indicating the work start position, direction and width of each shelf.
FIG. 4 is a diagram showing an example of the configuration of shelf information. As shown in FIG. 4, the shelf information is, for example, a table that associates and stores "shelf number", "work start position", "direction" and "width".

The "shelf number" is as described above.
The "work start position" is coordinates indicating the position where the self-propelled robot 100 starts reading the wireless tag as the position of the shelf. For example, the "work start position" indicates a position facing one end of the shelf and separated from the shelf by a certain distance. "Work start position" is coordinates in a predetermined coordinate system.
"Direction" indicates the direction in which the front of the shelf faces. The surface of the shelf where articles are exposed is called the front surface of the shelf. That is, the "direction" is the direction in which the articles on the shelf are exposed. "Direction" is an angle with respect to a given axis.
"Width" indicates the width of the shelf and the displacement from the "work start position" to the "work end position". For example, "width" is the x-coordinate of one end of the shelf minus the x-coordinate of the other end of the shelf. Alternatively, "width" is the x-coordinate of one end minus the x-coordinate of the other end of the area where the article is exposed. Here, one end indicates the end closer to the "work start position", and the other end indicates the end closer to the "work end position". That is, "width" indicates displacement in a predetermined coordinate system. Also, the absolute value of "width" indicates the distance in a predetermined coordinate system. That is, the absolute value of "width" indicates the width of the shelf. Further, the (x, y) coordinates obtained by adding the value of the "width" to the x coordinate of the "work start position" indicate the "work end position". The "work end position" indicates a position facing one end of the shelf and separated from the shelf by a certain distance.

FIG. 5 is a diagram showing an example of shelf information. That is, FIG. 5 is a plan view showing an arrangement example of shelves. For example, in the example shown in FIG. 5, the "work start position" of shelf A is coordinate P (400, 600). Also, the "direction" of the shelf A is "90". That is, shelf A faces upward in FIG. In the example shown in FIG. 5, the front of shelf A is the plane viewed from coordinates (400, 600) in the direction indicated by arrow a. On the other hand, the front of the shelf B is the plane viewed from the coordinates (150, 300) in the direction indicated by the arrow b. Thus, the direction in which the front of the shelf A faces is different from the direction in which the front of the shelf B faces.

When the reading system 1 reads the wireless tag of the article on the shelf A, the self-propelled robot 100 moves to coordinates (400, 600) facing the front of the shelf A. The self-propelled robot 100 moves leftward (negative direction of the x-axis) from the coordinates (400, 600) and reads the wireless tags of the articles on the shelf A.

When articles are densely displayed on a shelf, the wireless tags are close to each other, increasing the density of the wireless tags. As the density of wireless tags increases, the antenna characteristics of the wireless tags change. When the antenna characteristics of the wireless tag change, the communicable distance between the antenna 104 of the reading system 1 and the RF tag tends to become shorter. Therefore, when the reading system 1 reads the tag information of the RF tags on a shelf where articles are densely displayed, it is preferable that the antenna 104 is as close to the article as possible from the front side of the shelf. Therefore, the information on the "direction" included in the shelf information is effective information for the reading system 1 to reduce misreading of RF tags.

The shelf information is stored in the NVM 14 by an operator or the like. The processor 11 may also receive shelf information from an external device and store it in the NVM 14 . Also, the shelf information may be updated as appropriate.
Note that the configuration of the shelf information is not limited to a specific configuration.

Next, article information will be described. The item information is information related to items stored on the shelf. That is, the item information indicates the number of wireless tags stored on the shelf. Also, the product information indicates the theoretical inventory.

FIG. 6 is a diagram showing an example of the configuration of article information. As shown in FIG. 6, the article information is, for example, a table that associates and stores "article number", "unique ID", "name", "color", "size" and "shelf number".

"Item number" is an identification number for managing the item. For example, an "article number" is assigned to each SKU (stock keeping unit) (minimum management unit) of an article.
"Unique ID" is identification information for uniquely identifying an article. A "unique ID" is uniquely assigned to each article.
"Name", "Color" and "Size" indicate attributes of the article.
"Shelf number" indicates the shelf in which the item is stored.

Article information is stored in the NVM 14 by an operator or the like. The processor 11 may also receive article information from an external device and store it in the NVM 14 . Also, the article information may be updated as appropriate.
Note that the configuration of the article information is not limited to a specific configuration.

Next, reading distance instruction information will be described. The reading distance instruction information is information regarding the reading distance from the antenna 104 to the article. The reading distance instruction information is used to preliminarily designate an article to which the antenna 104 needs to be brought closer in order to reduce the reading error of the wireless tag by the reading system 1 .

FIG. 7 is a diagram showing an example of the configuration of reading distance instruction information. As shown in FIG. 7, the reading distance instruction information is, for example, a table that stores "number of times" and "reading distance" in association with each other.

"Number of Times" indicates how many times the reading process is performed. Read processing will be described later. In addition, although FIG. 7 shows up to the third time, the "number of times" may be up to the second time or the fourth time or more.
"Reading distance" indicates the distance from the antenna 104 to the shelf. A "reading distance" is a distance in a second direction perpendicular to the first direction. The distance from the antenna 104 to the shelf corresponds to the distance from the antenna 104 to the wireless tag attached to the article. That is, the longer the distance from the antenna 104 to the shelf, the longer the distance from the antenna 104 to the wireless tag attached to the article.

The reading distance information is stored in the NVM 14 by an operator or the like. The processor 11 may also receive reading distance information from an external device and store it in the NVM 14 . Also, the reading distance information may be updated as appropriate.
Note that the configuration of the reading distance information is not limited to a specific configuration.

Next, read result information will be described. The reading result information is information generated by the processor 11 based on the tag information of the wireless tag in response to the reading of the wireless tag.
FIG. 8 is a diagram showing an example of the configuration of reading result information. As shown in FIG. 8, the reading result information is, for example, a table that associates and stores "timestamp" and "identifier".

"Timestamp" indicates the acquisition time when the processor 11 acquired the tag information from the wireless tag.
The “identifier” is information included in the tag information and is information that uniquely identifies the wireless tag. The "identifier" is formed by adding the above-mentioned "item number" and "unique ID".

The read result information is generated by processor 11 and stored in NVM 14 . For example, the processor 11 stores the identifier included in the tag information in the "identifier" every time the tag information is obtained by reading the wireless tag. Each time the processor 11 acquires tag information, it detects the acquisition time of the tag information and stores the acquisition time in the "timestamp".
Note that the configuration of the reading result information is not limited to a specific configuration.

Next, functions realized by the processor 11 will be described. The processor 11 implements the following functions by executing software stored in the ROM 12, NVM 14, or the like.

First, the processor 11 has a function of moving the self-propelled robot 100 to the "work start position" of a predetermined shelf.

For example, the processor 11 receives input of an operation to start work. The processor 11 will acquire work instruction information and shelf information from NVM14, if the said input is received. When the processor 11 acquires the work instruction information and the shelf information, the processor 11 specifies the "work start position" of the shelf based on the work instruction information and the shelf information.

After specifying the "work start position", the processor 11 specifies a route from the current position of the self-propelled robot 100 to the "work start position". For example, the processor 11 acquires map information of the store where each shelf is installed. For example, the map information includes information such as shelf positions, travelable areas, non-travelable areas, and obstacle positions. Processor 11 identifies the route based on the map information.

After specifying the route, the processor 11 moves the self-propelled robot 100 along the route. For example, the processor 11 controls the movement mechanism 200 to move the self-propelled robot 100 along the route. Note that the processor 11 may modify the route to avoid obstacles detected by the sensor 103 .

The processor 11 moves the self-propelled robot 100 to the "work start position" of a predetermined shelf by moving the self-propelled robot 100 along the route. The processor 11 stops the self-propelled robot 100 after moving the self-propelled robot 100 to the “work start position”.

The processor 11 also has a function of reading wireless tags using the antenna 104 and reader 210 .

For example, when the self-propelled robot 100 reaches the "work start position", the processor 11 uses the antenna 104 and the reader 210 to transmit a request to the wireless tag and acquires tag information from the wireless tag.

The processor 11 also has a function of controlling the moving mechanism 200 to change the reading distance from the antenna 104 to the article based on the tag information of the wireless tag through the antenna 104 . Here, the processor 11 determines whether or not it is necessary to change the reading distance from the antenna 104 to the article in order to control the moving mechanism 200 .

The processor 11 also has a function of determining whether the self-propelled robot 100 has moved to the other end of the shelf.

For example, processor 11 acquires the rotation angle of motor 202 from rotary encoder 203 . The processor 11 calculates the distance traveled by the self-propelled robot 100 from the "work start position" from the rotation angle and the like. Note that the processor 11 may specify the movement distance further based on the obstacle detected by the sensor 103 . The processor 11 determines whether the moving distance has reached the "width" of the shelf information.

When the processor 11 determines that the self-propelled robot 100 has moved to the other end of the shelf, it ends reading the wireless tag.

If the work instruction information indicates multiple shelves, the processor 11 performs similar operations for each shelf. Also, when there is a plurality of pieces of work instruction information, the processor 11 performs the same operation for each piece of work instruction information.

Further, the processor 11 has a function of performing information processing related to inventory work based on the reading result information. Information processing related to inventory work is also called inventory processing.

For example, the processor 11 refers to the reading result information and acquires the unique ID from the identifier. That is, the processor 11 identifies the article attached with the wireless tag whose identifier has been read. After obtaining the unique ID, the processor 11 checks whether the articles are appropriately displayed on each shelf based on the article information.

For example, the processor 11 calculates the difference between the actually counted number (read number) and the theoretical inventory. The processor 11 creates information indicating an inventory result including the read count, the theoretical inventory, and the difference between the read count and the theoretical inventory for each article.

It should be noted that the processor 11 may transmit the reading result information to the host device, and the host device may perform information processing related to inventory work based on the reading result information.

The operation of the reading system 1 according to the embodiment will be described below with reference to FIGS. 9 to 11 and the like. It should be noted that the contents of the processing in the following description of the operation are examples, and various processing that can obtain similar results can be used as appropriate. 9 to 11 are flowcharts showing an example of processing by the processor 11 of the system controller 10. FIG. The processor 11 executes this process based on a program stored in the ROM 12 or NVM 14, for example. When the processor 11 proceeds to ACT(n+1) after processing ACTn (n is a natural number), description explaining this may be omitted.

In ACT 11 , the processor 11 acquires work instruction information from the NVM 14 .
In ACT 12, the processor 11 substitutes the variable S with the number of shelves included in the work instruction information. The number of shelves in the work instruction information is the initial value of the variable S. Variable S indicates the number of remaining shelves. A variable S indicates a serial number indicating which shelf is to be worked on.

In ACT13, the processor 11 substitutes 0 for the variable i. A variable i indicates how many reading processes the processor 11 performs on the shelf specified by the variable S. FIG. Read processing will be described later.
In ACT 14, the processor 11 substitutes the variable T with a value indicating the current time.

In ACT 15, the processor 11 refers to the work instruction information and obtains the shelf number indicated by the serial number assigned to the variable S. Then, the processor 11 acquires the shelf information of the shelf number.
In ACT16, the processor 11 acquires the work start position included in the shelf information acquired in ACT15.

In ACT17, the processor 11 acquires map information necessary for setting a route from the current position to the work start position acquired in ACT16. After the processing of Act17, the processor 11 proceeds to ACT18 in FIG.

In ACT18, the processor 11 uses the map information acquired in ACT17 to set a route from the current position to the work start position acquired in ACT16. A known method can be used to set the route.

In ACT19, the processor 11 controls the moving mechanism 200 to move the self-propelled robot 100 to the work start position obtained in ACT16 along the route set in ACT18.

In ACT 20, processor 11 executes the reading process shown in FIG.
In ACT 31, the processor 11 refers to the reading distance instruction information and acquires the reading distance. The processor 11 identifies, from the read distance instruction information, a record in which the number of times included in the read distance instruction information is the value of the variable i. Then, the processor 11 acquires the reading distance associated with the number of times from the record.

In ACT 32 , the processor 11 controls the movement mechanism 200 and the like to adjust the position of the self-propelled robot 100 . That is, the processor 11 moves the self-propelled robot 100 so that the distance between the antenna 104 and the shelf is the reading distance obtained in Act31. At the same time, the processor orients self-propelled robot 100 so that antenna 104 faces the front of the shelf. The position of the self-propelled robot 100 after the processing of ACT32 is hereinafter referred to as "reading start position".

In ACT 33, the processor 11 controls the antenna 104, the reader 210, etc. to start reading the wireless tag. The processor 11 acquires the tag information of the wireless tag read by the antenna 104 and the reader 210 until the reading of the wireless tag is stopped. Then, the processor 11 associates the identifier (item number+unique ID) included in the acquired tag information with the current time (time stamp) and stores it in the reading result information. However, if the same identifier as the read identifier is already stored in the read result information, the processor 11 does not newly store the identifier.

In ACT34, processor 11 sets the value of variable L to zero. Here, the variable L indicates the distance that the self-propelled robot 100 has moved along the first direction in parallel with the shelf from the reading start position.

In ACT35, the processor 11 moves the self-propelled robot 100 in the first direction at a predetermined speed while maintaining the distance between the antenna 104 and the shelf. However, the processor 11 moves the self-propelled robot 100 in the positive direction of the x-axis when the value of "width" is positive, and in the negative direction of the x-axis when the value of "width" is negative. .

In ACT 36, the processor 11 substitutes the moving distance of the self-propelled robot 100 from the reading start position into the variable L.

In ACT 37 processor 11 determines whether the value of variable L is less than the width of the shelf. Here, the width of the shelf is the absolute value of the width included in the shelf information acquired in ACT15. If the value of variable L is less than the width of the shelf, processor 11 determines Yes in ACT37 and returns to ACT36. Then, if the value of the variable L is equal to or greater than the width of the shelf, the processor 11 determines No in ACT37 and proceeds to ACT38.

In ACT 38, the processor 11 controls the antenna 104, the reader 210, etc. to stop reading the wireless tag.

In ACT 39 processor 11 determines the read rate. The reading rate can be obtained by (reading rate)=(the number of tags read)/(theoretical stock quantity). Here, the number of read tags is the number of identifiers included in the read result information whose associated time stamps are from the time indicated by the variable T to the current time. Also, the theoretical stock quantity is the number of articles whose associated shelf number is the shelf number indicated by the serial number assigned to the variable S, among the articles included in the article information. Therefore, the theoretical inventory quantity indicates the number of wireless tags assumed to be on the shelf. After the process of ACT39, the processor 11 ends the reading process and ends the process of ACT20 in FIG.

In ACT 21, the processor 11 determines whether or not the number of reading processes reaches the upper limit. That is, the processor 11 determines whether or not the variable i is greater than or equal to the upper limit of times. The upper limit of the number of times is determined in advance by an operator or the like and stored in the NVM 14 or the like, for example. If the variable i is less than the upper limit of the number of times, the processor 11 determines No in ACT21 and proceeds to ACT22.

In ACT22, the processor 11 determines whether or not the reading rate is equal to or less than the threshold. The threshold is determined in advance by an operator or the like and stored in the NVM 14 or the like, for example. If the reading rate is equal to or less than the threshold, the processor 11 determines Yes in ACT22 and proceeds to ACT23.
In ACT23, processor 11 increments the value of variable i by one. After processing ACT23, the processor 11 returns to Act18.

As described above, when the reading rate is equal to or less than the threshold value, the processor 11 performs the reading process again for the shelf number indicated by the serial number assigned to the variable S. However, the number of times the reading process is performed for the same shelf is up to the upper limit of the number of times. Note that the m (m is a natural number)-th reading process (reading process when i=m) is an example of the first reading operation. The (m+1)th reading process (reading process when i=(m+1)) is an example of the second reading operation.

If the reading rate is equal to or less than the threshold, the processor 11 determines No in ACT22 and proceeds to ACT24. Also, if the variable i is equal to or greater than the upper limit of the number of times, the processor 11 determines Yes in ACT21 and proceeds to ACT24.
In ACT24, processor 11 decrements the value of variable S by one.

In ACT25, processor 11 determines whether the value of variable S is greater than zero. If the value of the variable S is greater than 0, the processor 11 determines Yes in ACT25 and returns to ACT13 in FIG. On the other hand, if the value of the variable S is 0 or less, the processor 11 determines No in ACT25 of FIG. 10 and proceeds to ACT26.

In ACT 26, the processor 11 determines whether or not there is other work instruction information. If there is other work instruction information, the processor 11 determines Yes in ACT26 and proceeds to ACT11 in FIG. On the other hand, if there is no other work instruction information, the processor 11 determines No in ACT26 of FIG. 10 and proceeds to ACT27.
In ACT 27, the processor 11 performs the above-described inventory processing and the like.

When the reading rate of reading information from the wireless tags in the shelf is low, the reading system 1 of the embodiment shortens the distance between the antenna 104 and the wireless tags and performs the reading process again for the shelf. Thereby, the reading system 1 can improve the reading rate. The reason why the reading process is performed again after shortening the distance between the antenna 104 and the wireless tag, in addition to simply performing the reading process multiple times, is as follows.
The shorter the reading distance from the antenna 104 to the item, the narrower the detection range of one antenna 104 on the shelf. Therefore, in order to widen the detection range of one antenna 104 on the shelf, it is preferable that the reading distance from the antenna 104 to the article is long. Further, when the density of the wireless tags is low, the wireless tag attached to the article can sufficiently receive the power emitted from the antenna 104 even if the reading distance from the antenna 104 to the article is not short. Therefore, when the density of wireless tags is low, it is preferable that the reading distance is longer than when the density of wireless tags is high. On the other hand, when the density of the wireless tags is high, the proximity of the wireless tags may change the antenna characteristics of the wireless tags. As a result, the wireless tag may not be able to receive sufficient power emitted from the antenna 104 . As a result, when the density of wireless tags is high, the reading rate may be lower than when the density of wireless tags is low. In such a case, the reading system 1 can increase the power received by the wireless tag by shortening the distance between the antenna 104 and the wireless tag. Therefore, the reading system 1 can further improve the reading rate by changing the reading distance and performing the reading process again.

The reading system 1 of the embodiment changes the distance between the antenna 104 and the shelf by changing the distance between the self-propelled robot 100 and the shelf. Since the self-propelled robot 100 is provided with a movement mechanism for self-propelled movement, the movement mechanism may be used to change the distance between the antenna 104 and the shelf. is not necessary.

The above embodiment can also be modified as follows.
The reading system 1 moves the self-propelled robot 100 in the direction opposite to that of the first reading process (when i is 1) in the movements of ACT35 to ACT37 in the second and subsequent reading processes (when i is 2 or more). You can let me. That is, the self-propelled robot 100 may read wireless tags while moving in the first direction from the work end position side to the work start position side. In this case, the self-propelled robot 100 moves in the opposite direction between the m-th reading process and the m+1-th reading process. No need to go back to the edge. Therefore, the reading system 1 in this case can quickly perform reading processing multiple times.

In the above embodiment, the reading system 1 adjusts the distance between the antenna 104 and the shelf by changing the distance between the self-propelled robot 100 and the shelf in ACT 32 or the like. However, the antenna included in the self-propelled robot of the embodiment may be movable so as to change the distance from the shelf. In this case, the reading system may adjust the distance between the antenna and the shelf by moving the antenna instead of changing the distance between the self-propelled robot 100 and the shelf. Alternatively, the reading system in this case may adjust the distance between the antenna and the shelf by moving the antenna in addition to changing the distance between the self-propelled robot 100 and the shelf.

In the above embodiment, the reading system 1 performs reading processing for each shelf. That is, in the above embodiment, the predetermined range to be read in one reading process is one shelf. However, the range need not be one shelf. For example, the range is two or more shelves. Alternatively, the area may be part of a shelf, such as half of a shelf. Alternatively, the range may be a range according to another division method.
Further, the reading system 1 may have the article 300 attached with the wireless tag 301 in another place instead of the shelf.

In the above embodiment, reading system 1 used the same reading distance for every shelf. However, the reading system 1 may perform reading processing using different reading distances for each shelf. In this case, the reading distance instruction information stores the reading distance for each number of times for each shelf.
Further, the reading system 1 may vary the reading distance according to the type of product on the shelf. In this case, the reading distance instruction information stores the reading distance for each number of times for each product type.
For example, since T-shirts are less bulky than sweaters and sweatshirts, they are more likely to be densely displayed on shelves than sweaters and sweatshirts. Therefore, the radio tags attached to T-shirts are likely to have a higher density than the radio tags attached to sweaters and sweatshirts. For this reason, the reading system 1 can increase the reading rate by making the reading distance of the shelf on which T-shirts are placed shorter than the reading distance of the shelf on which sweaters and sweatshirts are placed.

The self-propelled robot 100 may be equipped with the system controller 10 . Also, the self-propelled robot 100 may implement some or all of the functions implemented by the processor 11 of the system controller 10 .

In the above embodiment, the self-propelled robot 100 uses the sensor 103 and the rotary encoder 203 to estimate its own position. However, the self-propelled robot 100 may perform self-position estimation using other methods. For example, the self-propelled robot 100 estimates its own position using a global navigation satellite system (GNSS) such as a global positioning system (GPS), or an indoor positioning system (IPS) such as an indoor messaging system (IMES).

The reader of the embodiment may be moved by means other than wheels. For example, embodiment readers move by tracks, legs, or the like.

The reader of embodiments may be an aircraft such as an unmanned aerial vehicle (UAV). The reading device, which is a UAV, may be, for example, a so-called drone such as a multicopter that flies with a plurality of rotors. In this case, the reading device is provided with a flying mechanism such as a rotor instead of the wheels 102 . The reader, which is an aircraft, can be used even when it is difficult to move on the ground, such as in a place where there is no space to travel or in a high place.

The reader of the embodiment may be a vessel such as a USV (unmanned surface vehicle). In this case, the reading device is provided with a propulsion device or the like for moving on water instead of the wheels 102 . A reader, which is a ship, is useful for reading wireless tags installed on or under water.

The reader of the embodiment may be a submersible such as a UUV (unmanned underwater vehicle). In this case, instead of the moving mechanism 200, the reading device has a propulsion device for traveling on and under water, and a submersible mechanism for sinking and surfacing. A reader, which is a submersible, is useful for reading wireless tags installed underwater or on the bottom of the water.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 1... Reading system 10... System controller 11... Processor 12... ROM 13... RAM 14... NVM 15... Communication part 100... Self-propelled robot 102... Wheel 103... Sensor 104... Antenna 104a Antenna 104b Antenna 104c Antenna 104d Antenna 200 Moving mechanism 201 Running controller 202 Motor 203 Rotary encoder 210 Reader 300 Article 301 Wireless tag

Claims (4)

a moving device for moving a moving object;
An antenna provided on the mobile body for receiving radio waves transmitted from wireless tags attached to products on the shelf ;
a first reading operation of reading information stored in the wireless tag of the shelf using the antenna while moving the mobile object from the start position of the shelf ;
and, if the reading rate for reading information from the wireless tag on the shelf by the first reading operation is equal to or less than a threshold value, move the moving body to the start position on the shelf, and The antenna is used to scan the wireless tag on the shelf while moving the moving object from the starting position on the shelf , with the distance being set to be shorter than the distance between the antenna and the wireless tag in the first reading operation . reading the information stored in the tag, performing a second reading operation for each shelf ;
a controller; and a reader. The control unit makes the distance between the mobile object and the wireless tag in the second reading operation shorter than the distance between the mobile object and the wireless tag in the first reading operation, 2. The reader according to claim 1, wherein the distance between said antenna and said wireless tag in said second reading operation is made shorter than the distance between said moving object and said wireless tag in said first reading operation. . 2. The reading rate is a value of a ratio of the number of the wireless tags on the shelf whose information has been read by the first reading operation to the number of the wireless tags assumed to be on the shelf. 3. A reader according to claim 2. including moving bodies and control devices,
The moving body is
a moving device for moving the moving body;
an antenna for receiving radio waves transmitted from wireless tags attached to products on the shelf ;
The control device is
a first reading operation of reading information stored in the wireless tag of the shelf using the antenna while moving the mobile object from the start position of the shelf ;
and, if the reading rate for reading information from the wireless tag on the shelf by the first reading operation is equal to or less than a threshold value, move the moving body to the start position on the shelf, and The antenna is used to scan the wireless tag on the shelf while moving the moving object from the starting position on the shelf , with the distance being set to be shorter than the distance between the antenna and the wireless tag in the first reading operation . a second read operation to read the information stored in the tag;
reading system, comprising a control unit that controls the moving body so as to perform the above for each shelf .

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