Automated inventory robot

Abstract

To provide an automated inventory robot that can automatically execute an inventory by reading a product RFID tag and a position RFID tag in a shop and moving around the shop.SOLUTION: In step S3401, an automated inventory robot moves a predetermined distance at a predetermined speed. In step S3402, the automated inventory robot calculates a duplicate reading rate, which is a rate at which the product RFID tag is read twice. When the duplicate reading rate is greater than or equal to a threshold, the automated inventory robot proceeds to step S3401. However, when the duplicate reading rate is lower than the threshold, it means that there are still many new product RFID tags being read; and in order to reliably read the position RFID tag, in step S3403, the automated inventory robot performs a predetermined second stopping operation.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a robot that automatically performs inventory. [Background technology]

[0002] 2. Description of the Related Art Conventionally, in stores, "inventory" is periodically conducted to check how many products are in the store. In Patent Document 1, the applicant discloses a technology in which item RFID tags (also called "product RFID tags") are attached to products and location RFID tags that indicate their location are attached to fixtures such as shelves and floors, and store staff read the RFID tags with a handheld reader as they move around the store. Product RFID tags and location RFID tags that are read at approximately the same time can be assumed to be in the same place, so information on where the products are located can be obtained. The technology in Patent Document 1 can be used for inventory counting. However, since products may be placed high on the shelves, the technology in Patent Document 1 requires the store clerk to read the RFID tag while changing the orientation of the handheld reader up and down. This causes a lot of fatigue in the store clerk's arms. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6803089 Summary of the Invention [Problem to be solved by the invention]

[0004] The applicant developed a robot that automatically reads product RFID tags and location RFID tags within a store while moving around the store. However, in experiments, it was found that while it was possible to achieve a 100% product RFID tag reading rate by slowing the robot's movement speed sufficiently, even with a 100% reading rate, the rate at which the position was incorrectly determined did not fall below a satisfactory value. After investigating the cause, it was determined that the robot was moving too quickly, which resulted in it failing to read location RFID tags. Therefore, a solution was devised to control the robot's movement within the store depending on the reading status of the product RFID tags. Furthermore, attaching location RFID tags to fixtures such as shelves and floors to indicate their location takes a great deal of time and effort in large stores, so it would be desirable to realize a product management system that does not require the attachment of location RFID tags.

[0005] An object of the present invention is to provide an automatic inventory robot that automatically controls the manner in which it moves within a store. Another object of the present invention is to provide a product management system that does not require affixing positional RFID tags to fixtures such as shelves and floors. [Means for solving the problem]

[0006] The inventors discovered that by controlling the way an automated inventory robot moves within a store depending on the reading status of product RFID tags, the number of failures in reading positional RFID tags can be reduced, leading to the completion of this invention. The inventors also discovered that if an obstacle map is created using an obstacle map creation robot, automatic inventory is possible even on floors where positional RFID tags are not attached, and this led to the completion of the present invention.

[0007] (1) A first automatic inventory robot according to the present invention is an automatic inventory robot that automatically travels around a floor in a store and reads product RFID tags and location RFID tags, and is equipped with a duplicate reading rate calculation unit that calculates a duplicate reading rate, which is the percentage of duplicate readings of product RFID tags, a movement instruction creation unit that creates movement instructions to control the movement of the automatic inventory robot based on the duplicate reading rate, and a travel control unit that controls the movement of the automatic inventory robot in accordance with the movement instructions. (2) The movement instruction creation unit may create movement instructions that are based on the operation of moving a predetermined distance at a predetermined speed and then stopping for a predetermined period of time, and if the duplicate reading rate is equal to or greater than a threshold, omit the operation of stopping for a predetermined period of time. (3) The first automated inventory robot according to the present invention may include upper and lower antennas having directionality. (4) The obstacle map creating robot according to the present invention includes a human-following driving control unit that causes the obstacle map creating robot to drive following a human; a driving history recording unit that records a driving history; a current position coordinate calculation unit that calculates the current position coordinates of the obstacle map creating robot based on the driving history; a lidar unit that detects the distance to an obstacle; an obstacle map creating unit that creates an obstacle map based on the distance to the obstacle and the current position coordinates of the obstacle map creating robot; and an overlay unit that overlays the obstacle map on a floor plan. Equipped with. (5) The obstacle map creation robot according to the present invention may further include a section determination unit that divides the aisles on the floor into a plurality of sections corresponding to each shelf based on the result of overlaying the obstacle map and the floor plan. (6) The obstacle map creating robot according to the present invention may further include a section / shelf number conversion table creating unit that creates coordinate information defining the section and creates a correspondence table between the coordinate information and shelf numbers. (7) The control method of the present invention is a control method for an automatic search robot that is capable of moving and reading RFID tags, which calculates a duplicate read rate, which is the percentage of RFID tags that are read twice, and controls the movement of the automatic search robot based on the duplicate read rate. (8) The control method according to the present invention may determine the self-position of the automatic search robot by reading a positional RFID tag attached to a predetermined position in a planned travel area. (9) The control method according to the present invention may include sequentially recording the travel route of the automatic search robot, and determining the self-position of the automatic search robot from the travel route. (10) In the control method according to the present invention, the self-location and the read result of the RFID tag of the search target may be recorded in association with each other. (11) A second automatic inventory robot according to the present invention is an automatic inventory robot that travels within a predetermined area and reads product RFID tags attached to products placed within the predetermined area, and includes a current position calculation unit that calculates current position information that enables determination of the current position of the automatic inventory robot within the predetermined area, a memory unit that stores information read from the product RFID tags in association with the current position information, a duplicate read rate calculation unit that calculates a duplicate read rate, which is the percentage of duplicate reads of the product RFID tags, and a movement control unit that creates movement instructions to control the movement of the automatic inventory robot based on the duplicate read rate. (12) A third automatic inventory robot according to the present invention is an automatic inventory robot that automatically travels around a store floor and reads product RFID tags, and is equipped with a control unit that controls a process of calculating the coordinates of the current position of the automatic inventory robot by adding the amount of movement of the automatic inventory robot to the coordinates of the starting point based on the orientation of the automatic inventory robot at the starting point. [Effects of the Invention]

[0008] According to the present invention, an automatic inventory robot can automatically perform inventory, thereby reducing the burden on store staff. Furthermore, according to the present invention, an automatic inventory robot can be used to perform inventory even on floors where no positional RFID tags are attached, thereby eliminating the need to attach positional RFID tags and further reducing the burden on store staff. [Brief explanation of the drawings]

[0009] [Figure 1]FIG. 1 is a diagram illustrating an automatic inventory robot according to a first embodiment of the present invention. [Figure 2] FIG. 1 is a diagram showing an example of a floor layout of a store according to a first embodiment of the present invention. [Figure 3] FIG. 2 is a diagram showing functional blocks of a tablet according to the first embodiment of the present invention. [Figure 4] FIG. 3 is a diagram showing a processing flow in the tablet according to the first embodiment of the present invention. [Figure 5] FIG. 10 is a diagram illustrating an example of calculation of a duplicate read rate according to the first embodiment of the present invention. [Figure 6] FIG. 10 is a diagram showing an obstacle map creation robot according to a second embodiment of the present invention. [Figure 7] FIG. 10 is a diagram showing functional blocks of a tablet according to a second embodiment of the present invention. [Figure 8] 10 is an example of an obstacle map created by an obstacle map creation unit according to a second embodiment of the present invention. [Figure 9] 10 is a diagram showing the result of an overlay unit in accordance with the second embodiment of the present invention overlaying a rotated and scaled obstacle map onto a floor plan. [Figure 10] FIG. 10 is a diagram showing the result of dividing an aisle into a plurality of sections corresponding to each shelf by a section determination unit according to the second embodiment of the present invention. [Figure 11] FIG. 10 is a diagram showing an example of a section / shelf number conversion table created by a section / shelf number conversion table creation unit according to the second embodiment of the present invention. [Figure 12] FIG. 10 is a floor plan for explaining a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. [Embodiment 1] FIG. 1 is a diagram showing an automatic inventory robot 3100 according to the first embodiment of the present invention. The automated inventory robot 3100 includes a reader 3030, an upper antenna 3010, a lower antenna 3020, a tablet 3040, a travel control unit 3060, and wheels 3050. The reader 3030 wirelessly communicates with product RFID tags and location RFID tags via the upper antenna 3010 and the lower antenna 3020, and reads these RFID tags.

[0011] The upper antenna 3010 has a directivity center at 45 degrees upward so as to read the product RFID tags of products placed in high places. The lower antenna 3020 has a directivity center in the horizontal direction so as to read the product RFID tags and location RFID tags of products placed in low places. The tablet 3040 receives information from the RFID tags read by the reader 3030 and creates instruction information for controlling the movement of the automated inventory robot based on that information. In FIG. 1, the reader 3030 is partially hidden by the tablet 3040. The travel control unit 3060 controls the movement of the automated inventory robot 3100 according to the instruction information from the tablet 3040.

[0012] A plurality of products 3300 are placed on the fixture 3200. A product RFID tag 3350 is attached to the product 3300. A location RFID tag 3450 is attached to the bottom of the fixture 3200. Number 3400 is the floor.

[0013] Upper antenna 3010 and lower antenna 3020 are configured with antenna arrays arranged in a matrix to receive reflected waves, with the center of directivity in the normal direction from the center of the plane on which the matrix is ​​formed, and an effective reception angle of approximately 45 degrees. Both upper antenna 3010 and lower antenna 3020 are arranged on the side of the direction in which automated inventory robot 3100 travels during inventory, with upper antenna 3010 facing upward at an angle of 45 degrees to the plane of floor 3400, and lower antenna 3020 being arranged so that its effective reception angle is parallel to floor 3400.

[0014] 1, automated inventory robot 3100 moves toward the back of the drawing, with its antenna facing to the right in the direction of travel. Therefore, the lower receiving end of upper antenna 3010 and the upper receiving end of lower antenna 3020 overlap, providing an effective receiving angle from floor surface 3400 on one side of automated inventory robot 3100 to almost directly above. By traveling parallel to the shelves at a distance of 30 cm to 90 cm from fixture 3200, it is possible to detect all product RFID tags installed on the shelves.

[0015] In the first embodiment, upper and lower antennas are arranged only on the right side of the traveling direction, and no antenna with an effective receiving angle is arranged on the left side of the traveling direction. The travel control unit 3060 outputs a control signal for controlling the output of a motor (not shown) that drives the wheels 3050, and causes the automated inventory robot 3100 to travel parallel to the fixtures 3200 at a speed of, for example, 500 m to 1 km per hour.

[0016] The tablet 3040 displays a UI (user interface) that allows a person to check the behavior of the automated inventory robot 3100 and the status of RFID tag reading, and to give instructions for behavior as needed. Similar functions can be achieved with a set of a PC (personal computer), monitor, mouse, and keyboard, but the tablet 3040 is lighter in weight and is fixed into one, making it easier to use. The display screen is positioned facing backward in the direction of travel so that a person can follow the autonomously traveling automated inventory robot 3100 and operate it while walking.

[0017] 2 is a diagram showing an example of a floor layout of a store according to the first embodiment of the present invention. A floor plan 3700 includes wall fixtures 3210 and 3230 that are adjacent to the wall, and a central fixture 3220 that looks like an island. "A001," "B001," etc. are shelf numbers. However, the floor plan 3700 does not have coordinate information with a certain point on the floor as the origin.

[0018] 3 is a diagram showing functional blocks of the tablet 3040 according to the first embodiment of the present invention. The tablet 3040 includes a control unit 3041, a storage unit 3042, and an input / output unit 3043. The control unit 3041 controls the operation of the tablet 3040 and also creates instruction information for controlling the movement of the automated inventory robot 3100. The control unit 3041 includes a duplicate reading rate calculation unit 3046 and a movement instruction creation unit 3047.

[0019] The reader 3030 reads RFID tags multiple times per second. Therefore, some of the RFID tags read this time are the same as the RFID tags read up to the previous time. The proportion of RFID tags that have already been read up to the previous time among the RFID tags read this time is defined as the "duplicate read rate." The duplicate read rate calculation unit 3046 calculates the duplicate read rate.

[0020] The reader 3030 sequentially stores the IDs read from the RFID tags in the storage unit 3042. The IDs read from the position RFID tags 3450 are stored in association with the IDs of the product RFID tags 3350 read at the same time, and the product is recognized as being placed on the fixture 3200 to which the position RFID tag 3450 is attached. In other words, reading the position RFID tag determines the current location, and in the first embodiment, the reader 3030 can be said to also function as a current location calculation unit, and the ID of the position RFID tag has the meaning of current location information indicating the current location.

[0021] The movement instruction creation unit 3047 creates instruction information to control the movement of the automated inventory robot 3100 according to the overlap read rate. In the first embodiment, the basic operation is to move a predetermined distance of 1 m to 1.5 m at a predetermined speed of 500 m to 1 km per hour, and then stop for a predetermined rest time of 1 second. If the distance is 1 m to 1.5 m, even if the automated inventory robot 3100 passes an RFID tag leaving an unreadable RFID tag, it can still read it at the stationary position. If the predetermined movement distance is set longer than this, it becomes difficult to read RFID tags that have passed by without being read, even if the robot stops. On the other hand, if the predetermined movement distance is too short, the robot will stop frequently, reducing inventory efficiency. Therefore, in the first embodiment, in which the travel path of the automated inventory robot 3100 is set 30 cm to 90 cm from the fixture 3200, a predetermined movement distance of 1 m to 1.5 m is optimal.

[0022] Here, if the duplicate read rate is equal to or greater than the threshold, it is determined that "the duplicate read rate is high. → New RFID tags are no longer being read. → All RFID tags in this location have already been read." Control can be exercised to omit the operation of stopping for a predetermined rest time, or to resume travel without waiting for the predetermined rest time of one second to elapse. In the first embodiment, if the duplicate read rate exceeds 65%, the read rate achieved approximately 100%. Therefore, in the first embodiment, the threshold for the duplicate read rate is set to 65%, and if the duplicate read rate during travel is less than the threshold, control is exercised to stop for a predetermined rest time, and travel is resumed when either the duplicate read rate exceeds 65% or one second has elapsed.

[0023] For example, in industries such as apparel and drugstores where a large number of items are displayed on fixtures, a 1% reading loss may not be a problem. In such cases, the threshold for the duplicate reading rate can be set low to reduce stationary time, or the travel speed can be set fast to shorten the time required for inventory. Conversely, in stores that handle brand-name goods or high-priced products, where even a 1% reading loss is unacceptable, it is advisable to set the threshold high or the travel speed slow. These thresholds, stationary time, and travel speed can be set from the tablet 3040.

[0024] In addition, the basic operation for all or part of the stationary operation may be to move a predetermined distance at a predetermined speed, and then slow the moving speed for a predetermined period of time.In this case, if the overlapping reading rate is above a threshold, the operation of slowing the moving speed for a predetermined period of time may be omitted, or the time for slowing down may be controlled to be shorter.

[0025] The read RFID information is stored in the storage unit 3042. The input / output unit 3043 is a part that inputs and outputs data to and from the tablet 3040, and is a touch panel or the like.

[0026] FIG. 4 is a diagram showing the flow of processing in the tablet 3040. Before START, the automated inventory robot 3100 is positioned at a predetermined start position within the store. Default values ​​and values ​​previously specified by the user for the travel speed, specified rest time, and specified travel distance are stored in the memory unit 3042. If a user-specified value exists, that set value is displayed on the display screen; if not, the default value is displayed. The START button is displayed on the screen, and the robot is in a standby state waiting for the user to press it.

[0027] By pressing START, the data from the previous inventory remaining in the memory unit 3042 is cleared, and the automated inventory robot 3100 begins moving in a predetermined direction. The reader 3030 is then activated to begin reading RFID tags. The RFID tags receive radio waves emitted from the upper antenna 3010 and the lower antenna 3020, respectively, via the location RFID tag 3450 and the product RFID tag 3350. The generated electromotive force transmits a predetermined ID stored in the RFID tag back to the reader 3030. The reader 3030 sequentially stores the RFID tags it reads in the memory unit 3042. In the first embodiment, the reader 3030 transmits radio waves 100 to 400 times per second and receives corresponding replies 100 to 400 times per second. Because each RFID tag replies with a specific ID, the same ID is received each time a reply is received from the same RFID tag. Consequently, the same ID is stored multiple times in the memory unit 3042.

[0028] Here, if the read ID of the position RFID tag is different from the expected RFID tag ID, it can be assumed that START was pressed at a location other than the expected starting point, and the vehicle can stop traveling and enter a standby mode to wait for user input, or the vehicle can recognize its own position from the read RFID tag and the furniture layout map stored in memory unit 3042 and perform control to correct the route.

[0029] In step S3401, the movement instruction creation unit 3047 creates a movement instruction to move a predetermined distance at a predetermined speed and sends it to the travel control unit 3060. The movement instruction creation unit 3047 reads the ID of the last read position RFID tag from the memory unit 3042 as needed, and creates a travel history of the automated inventory robot 3100 traveled within the store while comparing it with the fixture layout map. In step S3402, the overlapping reading rate calculation unit 3046 calculates the overlapping reading rate, and determines whether the overlapping reading rate is equal to or greater than a threshold value. If the overlapping reading rate is equal to or greater than the threshold, the process proceeds to step S3401. If the overlapping reading rate is not equal to or greater than the threshold, the process proceeds to step S3403.

[0030] In step S3403, the automatic inventory robot 3100 is stopped for the number of seconds set as the predetermined rest time. In step S3404, it is determined from the travel history whether the robot has reached the end of a circuit around the store floor, and if so, the reader 3030 is stopped and the automated inventory robot 3100 is caused to travel to a predetermined end position, thereby terminating the operation. If the robot has not reached the end, the process returns to step S3401. In this way, the movement of the automated inventory robot 3100 is controlled according to the duplicate reading rate, so that the occurrence of incorrectly determining position information without reading the position RFID tag is reduced.

[0031] FIG. 5 is a diagram illustrating an example of calculation of the overlapping read rate. Item P1 indicates the number of times the reading has been performed. Item Q1 indicates the ID of the product RFID tag that has been read. In Figure 5, the number of IDs in item Q1 is 4 each time, but the number of IDs in item Q1 can be different each time. Item R1 is the number of IDs in the product RFID tag that has been read.

[0032] Item S1 is the ID of the product RFID tag that has already been read from item Q1. Item T1 is the number of IDs in item S1. Item U1 is the duplication rate calculated as T1 / R1.

[0033] As described above, in the first embodiment of the present invention, the basic operation is to move a predetermined distance at a predetermined speed and then stop for a predetermined time, and if the duplicate reading rate is equal to or greater than a threshold, the operation of stopping for the predetermined time is controlled to be omitted. This ensures sufficient time to read the position RFID tag, reducing the number of malfunctions such as incorrectly determining the position of a product.

[0034] [Embodiment 2] FIG. 6 is a diagram showing an obstacle map creating robot 3121 according to the second embodiment of the present invention. The reader 3030, upper antenna 3010, lower antenna 3020, and wheels 3050 of the obstacle map creation robot 3121 are the same as those of the automated inventory robot 3100 of the first embodiment.

[0035] The obstacle map creation robot 3121 is equipped with a tablet 3040, a human-following driving control unit 3090, and a lidar unit 3080. The tablet 3040 creates a map of obstacles on the floor based on the information acquired by the LIDAR unit 3080. The tablet 3040 also creates a conversion table from floor position coordinates to shelf numbers by overlaying the created obstacle map on the floor plan 3700.

[0036] The lidar unit 3080 has a Lidar (Light Detection and Ranging, Laser Imaging Detection and Ranging) function. Lidar is a type of remote sensing technology that uses light, and can measure the distance to a distant object by measuring scattered light in response to a pulsed laser beam. The lidar unit 3080 is oriented in the same direction as the upper antenna 3010 and the lower antenna 3020, and in the second embodiment, has directivity to the right of the traveling direction of the obstacle map creation robot 3121, which travels in the depth direction of the drawing. The lidar unit 3080 records the distance measurement results in the memory unit 3042 as needed, linking them to time information from the start of operation. The human following running control unit 3090 controls the obstacle map creating robot 3121 so that it moves behind a human walking within the floor. The lidar unit 3080 also constantly measures the distance to a person walking in front of the obstacle map creation robot 3121 and records the distance from the obstacle map creation robot 3121 to the person in the memory unit 3042.

[0037] The human-following running control unit 3090 outputs a drive command to the motor (not shown) to drive the wheels 3050 so that the vehicle follows the person within a range that does not exceed a pre-set maximum speed. At this time, the human-following running control unit 3090 uses the start point as the origin and calculates the coordinates of its own position from the history of drive commands to the motor, i.e., the running speed and time information, as needed, and stores this in the storage unit 3042. In this way, a running history is created from the history of the coordinates of its own position. In addition, the coordinates of obstacles can be calculated and created as a map from the distance measurement results of the LIDAR unit 3080 and the vehicle's own position.

[0038] Here, among the objects for which measurement data from the lidar unit 3080 exists, those whose coordinate positions do not change over time are reflected as obstacles in the obstacle map, while those whose coordinate positions change over time, such as people, are not reflected in the obstacle map. Therefore, during inventory work, an item that has fallen on the floor 3400 is initially detected by the lidar unit 3080, but if it is no longer detected because the person puts the item away, it is not reflected in the obstacle map, and even if it was once reflected, it is removed from the map and updated. The created map is updated as needed and displayed on the tablet 3040.

[0039] In this way, the obstacle map creating robot 3121 runs while creating a map in accordance with its own running, and is able to recognize its own position as coordinates within that map. As in the first embodiment, the reader 3030 reads the ID of the commodity RFID tag at any time via the upper antenna 3010 and the lower antenna 3020, and records the read commodity RFID tag ID in the memory unit 3042 in association with the coordinates of the obstacle (i.e., presumed to be the fixture 3200) detected at that time.

[0040] Similar to the first embodiment, a plurality of products 3300 are placed on the fixture 3200, and product RFID tags 3350 are attached to the products 3300. However, in the second embodiment, the fixture 3200 does not have a position RFID tag 3450 attached thereto.

[0041] FIG. 7 is a diagram showing functional blocks of a tablet 3040 according to the second embodiment of the present invention. The tablet 3040 includes a control unit 3041 , a storage unit 3042 , and an input / output unit 3043 . The control unit 3041 creates an obstacle map of the floor, and also creates a conversion table from floor position coordinates to shelf numbers by overlaying the created obstacle map on the floor plan 3700.

[0042] The control unit 3041 includes a travel history recording unit 4101 , a current position coordinate calculation unit 4102 , an obstacle map creation unit 4103 , an overlapping unit 4104 , a section determination unit 4105 , and a section / shelf number conversion table creation unit 4106 . The travel history recording unit 4101 keeps a record of the movement of the obstacle map creating robot 3121, including the direction and distance traveled. This movement record is stored in the memory unit 3042.

[0043] When the obstacle map creation robot 3121 moves within a floor, the current position coordinate calculation unit 4102 calculates the current position coordinates when a certain point within the floor is set as the origin, based on the travel history recorded by the travel history recording unit 4101. The obstacle map creation unit 4103 creates a map showing the positions of obstacles such as walls or furniture (hereinafter referred to as an “obstacle map”) based on the information created by the LIDAR unit 3080. The superimposing unit 4104 performs processing such as rotation and scaling on the obstacle map created by the obstacle map creating unit 4103, and then superimposes it on the floor plan 3700.

[0044] The section determination unit 4105 divides the aisles of the floor into a plurality of sections corresponding to each shelf, based on the result of overlaying the obstacle map on the floor plan 3700. The section / shelf number conversion table creation unit 4106 creates coordinate information that defines the section, and creates a correspondence table between the coordinate information and the shelf number.

[0045] Fig. 8 is an example of an obstacle map 3800 created by the obstacle map creation unit 4103. The obstacle map 3800 in Fig. 8 is an example of a map created by the obstacle map creation robot 3121 following a human as it moves around the floor in Fig. 2. Number 3840 corresponds to the wall portion of the floor in Figure 2. Number 3830 is a portion recessed from the wall due to the wall fixture 3210. Number 3810 corresponds to the passage portion. Number 3820 is a portion corresponding to the central fixture 3220.

[0046] FIG. 9 shows the result of overlaying unit 4104 overlaying obstacle map 3900, which is a rotated and scaled version of obstacle map 3800, onto floor plan 3700. As described above, floor plan 3700 does not necessarily have coordinate information with a certain point on the floor as its origin. In contrast, obstacle map 3900 has coordinate information with a certain point on the floor (typically the starting point where obstacle map creation robot 3121 starts its operation) as its origin. Therefore, by overlaying obstacle map 3800 created by obstacle map creation robot 3121 on floor plan 3700, it is possible to obtain the coordinate information of each piece of furniture on obstacle map 3900.

[0047] FIG. 10 is a diagram showing the state in which the section determination unit 4105 has divided the aisle into multiple sections A to C corresponding to each piece of furniture. By creating the correspondence relationship shown in FIG. 10, when an automated inventory robot receives radio waves from a product RFID tag on a floor where no positional RFID tags are attached, as shown in FIG. 6, it is possible to identify the section based on the coordinate position of the automated inventory robot and narrow down the shelf on which the product is located to two. For example, if it is determined that the automated inventory robot is in section C based on the coordinates of its current location when radio waves are received from a product RFID tag, it can be estimated that the product is on shelf A003 or B003.

[0048] FIG. 11 is a diagram showing an example of the section / shelf number conversion table 5000 created by the section / shelf number conversion table creation unit 4106. Item V1 is a section. Item W1 is coordinate information that defines the section. In Figure 11, the coordinate information that defines the section is a round number, but in reality, it will be an odd number. Item X1 is the shelf number of the shelf where the product with the product RFID tag is presumed to be located when the automated inventory robot receives radio waves from the product RFID tag and determines that it is in the section of item V1.

[0049] When an automated inventory robot receives radio waves from a product RFID tag, the first thing that is determined is the coordinates of the automated inventory robot's current location. Based on the coordinates of the automated inventory robot's current location, the shelf where the product is likely to be located is narrowed down by referencing the section / shelf number conversion table 5000. In the case of the table in Figure 11, the list is narrowed down to two shelves. Which of the two candidate shelves is the shelf can be determined by the orientation of the upper antenna 3010 and lower antenna 3020 when the automated inventory robot receives the radio waves from the product RFID tag.

[0050] In this way, if the obstacle map creation robot 3121 creates an obstacle map and creates a section / shelf number conversion table based on that obstacle map, inventory can be performed by an automatic inventory robot even on floors where position RFID tags are not affixed.

[0051] [Embodiment 3] In the second embodiment, the overlay unit 4104 performs processing to overlay an obstacle map 3900, which is a rotated and scaled version of an obstacle map 3800, on a floor plan 3700, as shown in FIG. However, since obstacle map 3800 is a map created by obstacle map creation robot 3121 through actual measurements, it is possible to predict that obstacle map 3800 will not overlap well with floor plan 3700 no matter how much it is rotated or enlarged or reduced. Therefore, it would be preferable if the process by which the overlay unit 4104 overlays the obstacle map 3900, which is a rotated and scaled version of the obstacle map 3800, onto the floor plan 3700 could be omitted.

[0052] The current position of the robot, based on the travel history of the automatic inventory robot 3100 or the obstacle map creation robot 3121, is determined with the robot's starting point as the origin. Therefore, if the coordinates of the robot's starting point on the floor plan 3700 are known, the current position of the robot on the floor plan can be determined. However, what the robot can record is the amount of movement in the x-axis direction and the amount of movement in the y-axis direction for the robot, not necessarily the amount of movement in the x-axis direction and the y-axis direction for the floor plan.

[0053] FIG. 12 is a floor plan for explaining the third embodiment. Point A in Figure 12 is the origin of the floor plan. Point B is the robot's starting point. Point C is the robot's current position. The coordinates of point B in a coordinate system with point A as the origin can be obtained using a ruler tool in drawing software. The y-axis direction for the robot is assumed to be the direction obtained by rotating the x-axis direction for the robot by 90 degrees counterclockwise. Whether the x-axis direction for the robot coincides with the x-axis direction of the coordinate system with point A as the origin, and whether the y-axis direction for the robot coincides with the y-axis direction of the coordinate system with point A as the origin, depends on the orientation of the robot at point B, which is the starting point.

[0054] At point B, which is the starting point, if the x-axis direction for the robot coincides with the x-axis direction of the coordinate system with point A as the origin, and the y-axis direction for the robot coincides with the y-axis direction of the coordinate system with point A as the origin, then the coordinate of point C in the coordinate system with point A as the origin can be calculated by simply adding the amount of movement in the x-axis direction for the robot to the x-coordinate of point B, and adding the amount of movement in the y-axis direction for the robot to the y-coordinate of point B.

[0055] However, if the robot's orientation at point B, its starting point, is rotated 90 degrees clockwise, the x-axis direction for the robot becomes the negative y-axis direction of the coordinate system with point A as the origin. The y-axis direction for the robot becomes the x-axis direction of the coordinate system with point A as the origin. Therefore, in this case, the coordinate of point C in the coordinate system with point A as the origin can be determined by adding the amount of movement in the y-axis direction for the robot to the x-coordinate of point B and subtracting the amount of movement in the x-axis direction for the robot from the y-coordinate of point B.

[0056] If the orientation of the robot at point B, its starting point, is rotated another 90 degrees clockwise, the x-axis direction for the robot becomes the negative x-axis direction in the coordinate system with point A as the origin. The y-axis direction for the robot becomes the negative y-axis direction in the coordinate system with point A as the origin. Therefore, in this case, the coordinate of point C in the coordinate system with point A as the origin can be determined by subtracting the amount of movement in the x-axis direction for the robot from the x-coordinate of point B, and subtracting the amount of movement in the y-axis direction for the robot from the y-coordinate of point B.

[0057] If the robot's orientation at point B, its starting point, is rotated another 90 degrees clockwise, the x-axis direction for the robot becomes the y-axis direction in the coordinate system with point A as the origin. The y-axis direction for the robot becomes the minus x-axis direction in the coordinate system with point A as the origin. Therefore, in this case, the coordinate of point C in the coordinate system with point A as the origin can be determined by subtracting the amount of movement in the y-axis direction for the robot from the x-coordinate of point B and adding the amount of movement in the x-axis direction for the robot to the y-coordinate of point B.

[0058] As described above, the robot can record only the amount of movement in the x-axis direction and the amount of movement in the y-axis direction. Therefore, by inputting the direction of the robot at point B, which is the starting point, into the robot, the amount of movement of the robot can be appropriately added to the coordinate value of point B, which is the starting point, to determine the coordinates of point C, which is the robot's current position with point A as the origin.

[0059] Once the coordinates of point C, which is the robot's current position with point A as the origin, are determined, the positions of all fixtures are set on floor plan 3700, so based on the orientation of the robot's antenna when it receives radio waves from the product RFID tag, it can be determined that "the product with the product RFID tag that received the radio waves is on shelf D003" or "the product with the product RFID tag that received the radio waves is on shelf C003."

[0060] In the first embodiment, the upper antenna 3010, the lower antenna 3020, and the LIDAR unit 3080 are arranged with their directivity facing to the right of the direction of travel, but they may of course be arranged to the left, in another direction, on both sides, or in all directions. In this case, antennas facing different directions will simultaneously detect the same RFID tag, so an algorithm is required to identify in which direction the RFID tag is located from the automated inventory robot. While such identification is possible by measuring changes in the RFID tag read rate due to changes in position or by measuring radio wave intensity, in the first embodiment, the direction of the RFID tag is identified in a simpler manner by arranging the antennas with directivity in only one direction.

[0061] Furthermore, in many stores, the distance between fixtures is set wide enough for shopping carts used in the store to pass each other. In the first embodiment, the automated inventory robot 3100 travels along a path 30 to 90 cm away from the fixture 3200. However, in physical stores, it is often not possible to provide 30 to 90 cm on either side of the automated inventory robot 3100. The directivity of the upper antenna 3010 and the lower antenna 3020 is not very wide when the antennas are in close proximity to each other. By providing a distance of 30 to 90 cm, the two antennas can cover the entire area from the floor 3400 to the ceiling. Therefore, even if antennas are placed on both sides of the automated inventory robot 3100, it is difficult to ensure a distance of 30 to 90 cm from both fixtures. Therefore, unless a larger number of antennas are installed, it will be impossible to read the product RFID tags 3350.

[0062] Therefore, it is more cost-effective to place the upper antenna 3010 and the lower antenna 3020 on one side. There is no problem if the lidar unit 3080 is placed on both sides, but if the direction to read RFID tags is one-sided, even if only the lidar unit 3080 is facing both sides, it will be necessary to go through the same passage again to point the antenna, so although the accuracy of the obstacle map may improve, the benefit is not enough to justify the increased cost. Therefore, it is sufficient to place the lidar unit 3080 only in the same direction as the antenna that reads RFID.

[0063] Although the above embodiments 1 to 3 have been described using a store as an example, this is not limited to this. RFID tags may be attached to tools in a factory, or to medical instruments in a medical institution, and various other applications are possible in which an RFID tag is attached to an object to be searched and the position of the RFID tag is identified using a self-propelled robot.

[0064] The above embodiment has been described using location RFID tags and product RFID tags, but wireless communication tags such as short-range Bluetooth (registered trademark) or optically readable tags such as QR Code (registered trademark) or barcodes may also be used. RFID tags do not require a power source and can be read even when products are overlapping, making them more suitable than wireless communication or optically readable tags. [Explanation of symbols]

[0065] 3010 Upper Antenna 3020 Lower Antenna 3030 Leader 3040 tablets 3041 Control Unit 3042 Storage section 3046 Duplicate Reading Rate Calculation Unit 3047 Movement Instruction Creation Department 3050 wheels 3060 Travel control unit 3080 Rider Section 3090 Human-following driving control unit 3100 Automatic inventory robot 3121 Obstacle Mapping Robot 3200 Fixtures 3350 Product RFID Tags 3450 Location RFID Tag 3700 Floor Plan 3800 Obstacle Map 4101 Driving history recording unit 4102 Current position coordinate calculation unit 4103 Obstacle Mapping Department 4104 Overlapping part 4105 Division Determination Department 4106 Section / Shelf Number Conversion Table Creation Department 5000 Section / Shelf Number Conversion Table

Claims

1. An automated inventory robot that automatically travels on the floor of a store and reads product RFID tags and location RFID tags, a duplicate read rate calculation unit that calculates a duplicate read rate, which is the rate at which the commodity RFID tags are read duplicately; a movement instruction creation unit that creates movement instructions for controlling movement of the automated inventory robot based on the overlap reading rate; a travel control unit that controls the movement of the automated inventory robot in accordance with the movement instruction; An automated inventory robot equipped with

2. 2. The automated inventory robot according to claim 1, wherein the movement instruction creation unit creates movement instructions that are based on the operation of moving a predetermined distance at a predetermined speed and then stopping for a predetermined period of time, and that omit the operation of stopping for a predetermined period of time if the duplicate reading rate is equal to or greater than a threshold.

3. 2. The automated inventory robot according to claim 1, comprising upper and lower directional antennas.

4. a human-following running control unit that causes the obstacle map creation robot to run following a human; a driving history recording unit that records a driving history; a current position coordinate calculation unit that calculates current position coordinates of the obstacle map creation robot based on the travel history; a lidar unit that detects the distance to an obstacle; an obstacle map creating unit that creates an obstacle map based on the distance to the obstacle and the current position coordinates of the obstacle map creating robot; a superimposing unit that superimposes the obstacle map and the floor plan; An obstacle map-making robot equipped with

5. 5. The obstacle map creating robot according to claim 4, further comprising a section determining unit that divides the aisles of the floor into a plurality of sections corresponding to the shelves based on the result of superimposing the obstacle map and the floor plan.

6. 6. The obstacle map creating robot according to claim 5, further comprising a section / shelf number conversion table creating unit that creates coordinate information defining the section and creates a correspondence table between the coordinate information and shelf numbers.

7. A control method for an automatic searching robot that can move and read RFID tags, comprising: Calculating a duplicate read rate, which is the rate at which the RFID tags to be searched are read duplicately; A control method for controlling the movement of the automatic search robot based on the overlap reading rate.

8. The control method according to claim 7, wherein the self-position of the automatic searching robot is determined by reading a positional RFID tag attached to a predetermined position in a planned travel area.

9. Sequentially recording the travel path of the automatic search robot; The control method according to claim 7, wherein the self-position of the automatic searching robot is determined from the travel route.

10. 10. The control method according to claim 8, wherein the self-location and the read result of the RFID tag of the search target are recorded in association with each other.

11. An automated inventory robot that travels within a predetermined area and reads commodity RFID tags attached to commodities placed within the predetermined area, a current position calculation unit that calculates current position information that enables determination of the current position of the automated inventory robot in the predetermined area; a storage unit that stores the information read from the commodity RFID tag in association with the current location information; a duplicate read rate calculation unit that calculates a duplicate read rate, which is a rate at which the commodity RFID tags are read duplicately; a movement control unit that generates a movement instruction to control the movement of the automated inventory robot based on the overlap reading rate; An automated inventory robot equipped with

12. An automated inventory robot that automatically travels around the store floor and reads product RFID tags, An automatic inventory robot including a control unit that controls a process of calculating the coordinates of the current position of the automatic inventory robot by adding the amount of movement of the automatic inventory robot to the coordinates of the start point based on the orientation of the automatic inventory robot at the start point.

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