JP2007049527A - Radio ic tag reader and moving-body reading system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radio IC tag reader (capable of high-speed reading) whose reading range is extended, and to provide a moving-body reading system which does not require complicated control, utilizes radio IC tags and the radio IC tag reader, and is highly reliable. <P>SOLUTION: The radio IC tag reader is equipped with a plurality of antennas 26, 27, 28, 29 for reading, by radio, data stored in a radio IC tag attached to a moving body, and has the following function. When a certain antenna among the plurality of antennas 26, 27, 28, 29 becomes incapable of detecting the radio IC tag, while data stored in the radio IC tag are read by the use of the plurality of antennas 26, 27, 28, 29, the reading operation for the data stored in the radio IC tag is interrupted, the antenna is switched over to a certain antenna among the plurality of antennas in a predetermined order, the antenna searches for the radio IC tag having become undetectable, and the interrupted reading operation for the data stored in the radio IC tag is resumed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wireless IC tag reader and a mobile object reading system using a wireless IC tag and a wireless IC tag reader.

  Currently, development of system applications using wireless IC tags and wireless IC tag readers that exchange data using wireless is underway. Each wireless IC tag has a unique ID and can be uniquely recognized, and a large amount of data can be stored in a semiconductor memory. Therefore, the wireless IC tag is actively used particularly in the fields of physical distribution management and article management.

  In logistics management, a wireless IC tag is used for automation of work in a warehouse. FIG. 5 is a perspective view showing a concept of a physical distribution management system for managing warehousing and delivery of a conventional example. As shown in FIG. 5, the antenna 13 of the wireless IC tag reader 12 is installed beside a conveyor 15 on which a load 14 with the wireless IC tag 11 attached is carried. By reading the data of the wireless IC tag 11 attached to the package 14 passing in front of the antenna 13 and recording the history of loading and unloading of the package, it is possible to construct a logistics management system for managing the loading and unloading. .

  In the process of reading data of a mobile object attached with a wireless IC tag attached to a package, the relationship between the reading time, the reading range, and the speed of the mobile object is important. The reading time needs to be shorter than the time required for the moving body to pass through the reading range (readable time).

  Since it is difficult to shorten the data reading time of the wireless IC tag, a method of extending the readable time by reducing the moving speed of the moving body or widening the reading range is generally used.

  As a method for reducing the moving speed of the moving body, there are a method for reducing the speed limit of the conveyor and a method for stopping the moving body within the reading range. Although effective in securing the readable time, there is a problem that the flow of the moving body is hindered and the work efficiency is likely to be deteriorated.

  As a method of expanding the reading range, there are a method of expanding the reading range of the antenna, a method of using a plurality of wireless IC tag readers, and a method of connecting a plurality of antennas to one wireless IC tag reader. Techniques relating to a method of connecting a plurality of antennas to one wireless IC tag reader are disclosed in Patent Document 1 and Patent Document 2.

  Patent Document 3 discloses a method of overlapping communication areas of a plurality of antennas attached to one wireless IC tag reader in order to expand the antenna reading range.

JP 2000-306054 A JP 2004-265113 A JP 2003-283367 A

  In Patent Document 1 and Patent Document 2 described above, since technical considerations for performing high-speed reading in a boundary region between a plurality of antennas are not sufficiently made, a phenomenon that wireless IC tag data cannot be completely read occurs. There has been a problem that a highly reliable mobile reading system using an IC tag and a wireless IC tag reader cannot be constructed.

  In the above-mentioned Patent Document 3, it is possible to realize high-speed reading in the boundary area of the plurality of antennas by overlapping the communicable areas of the plurality of antennas attached to one wireless IC tag reader. There is a problem that radio interference occurs between a plurality of antennas of a wireless IC tag and a wireless IC tag reader, and the construction of a system for controlling each wireless IC tag reader and antenna becomes complicated.

  The present invention has been made to solve the above-described problems, and the technical problem thereof is a wireless IC tag reader having an expanded reading range (enabling high-speed reading) and a wireless IC tag that does not require complicated control. It is to provide a highly reliable mobile reading system using a wireless IC tag reader.

  A first invention for achieving the above object is a wireless IC tag reader having a plurality of antennas for wirelessly reading data stored in a wireless IC tag attached to a mobile body, wherein When one of the antennas cannot detect the wireless IC tag during the operation of reading the data stored in the wireless IC tag, the reading operation is interrupted and predetermined. The wireless IC tag reader has a function of searching for a wireless IC tag that can no longer be detected by switching to another antenna among the plurality of antennas in order and restarting the reading operation.

  A second invention for achieving the above object comprises an interface with an external control system, a modulation circuit, a demodulation circuit, an antenna unit having a changeover switch and a plurality of antennas, and the CPU has an address A counter, an antenna counter, a wireless IC tag detection flag, and a data storage buffer. When the CPU receives a data read command from the control system, the CPU sets an address counter, resets the antenna counter, and sets the changeover switch. Switching, setting the antenna used for reading the wireless IC tag to the antenna indicated by the antenna counter, outputting a command from the set antenna to the wireless IC tag, reading the data of the wireless IC tag, Data read command transmission was successful, When the response data from the wireless IC tag is acquired, the wireless IC tag detection flag is set, the response data is stored in the buffer, and then the address counter is checked, and the address counter sets the specified number. If it exceeds, the read data stored in the buffer is returned to the control system, and if the address counter does not exceed the specified number, the address counter is incremented and the flow returns to the data reading process. A wireless IC tag reader to be executed.

  A third invention for achieving the above object includes an antenna unit having an interface with an external control system, a CPU, a modulation circuit, a demodulation circuit, a changeover switch, and a plurality of antennas. , An address counter, an antenna counter, a wireless IC tag detection flag, and a data storage buffer, and the CPU checks the wireless IC tag detection flag when there is no response from the wireless IC tag, and the wireless IC tag If the tag detection flag is set, the antenna switching process is performed. In the antenna switching process, first, the antenna counter is checked. If the specified number of the antenna counter is not exceeded, the increase of the antenna counter and the antenna counter are performed. Reset the wireless IC tag detection flag and return to the antenna set If the wireless IC tag detection flag is not set, or if the antenna counter exceeds the specified number, data reading fails, and the control system is notified that reading of the wireless IC tag data has failed. It is a wireless IC tag reader that executes a flow.

  According to a fourth aspect of the invention for achieving the above object, there is provided a moving body configured using a wireless IC tag reader having a plurality of antennas for wirelessly reading data stored in a wireless IC tag attached to the moving body. In the reading system, each antenna is installed in the wireless IC tag reader along the moving path of the mobile body to which the wireless IC tag is attached, and the wireless IC tag reader in which the mobile body is installed along the moving path. Reading of data of the wireless IC tag attached to the moving body from each antenna is started, and during the data reading operation, the moving body moves from the reading range of the antenna with each antenna, and the wireless IC tag When the tag cannot be detected, the antennas are sequentially switched according to the movement, and the reading operation is performed. A mobile reading system with an enlarged reading range of the wireless IC tag attached to the movable body.

  According to the present invention, in a wireless IC tag reader having a plurality of antennas for reading data stored in a wireless IC tag attached to a mobile body via wireless, the data stored in the wireless IC tag with a plurality of antennas is stored. If a certain antenna among the plurality of antennas cannot detect the wireless IC tag during the reading operation, the reading operation of the data stored in the wireless IC tag is interrupted, and the plurality of antennas are performed according to a predetermined order. By switching to a certain antenna, searching for a wireless IC tag that can no longer be detected, and resuming the reading operation of data stored in the suspended wireless IC tag, the wireless IC tag can be read during data reading. When the wireless IC tag moves from the reading range of the antenna, the wireless IC tag reader automatically changes to another antenna. You can continue to read data switched.

  In addition, according to the present invention, the antenna of the wireless IC tag reader is installed along the moving path of the moving body, and data can be read while switching the antenna in accordance with the movement of the moving body, so that the reading range for the moving body can be easily expanded. it can.

  As a result, it is possible to provide a wireless IC tag reader with an expanded reading range (allowing high-speed reading) and a highly reliable mobile reading system using a wireless IC tag and a wireless IC tag reader that do not require complicated control. Become.

  A wireless IC tag reader and a mobile body reading system according to the best mode for carrying out the present invention will be described below in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a wireless IC tag reader of the present invention. FIG. 2 shows a flowchart for reading the identification data stored in the wireless IC tag of the present invention. FIG. 3 shows an antenna switching flowchart in the wireless IC tag of the present invention. FIG. 4 is a perspective view showing an outline of the mobile body reading system of the present invention.

  As shown in FIG. 1, the wireless IC tag reader includes a CPU 21, a modulation circuit 22, a demodulation circuit 23, an interface 24 with a control system, and an antenna unit 30 including a separate unit. The antenna unit 30 includes an antenna 26 and antennas 27, 28, and 29 including an antenna changeover switch 25. The main operation of the wireless IC tag reader is as follows. A command sent from the control system is analyzed by the CPU 21 and converted into a command for the wireless IC tag. The wireless IC tag command is modulated by the modulation circuit 22 and sent to the wireless IC tag via the antennas 26, 27, 28 and 29. The response from the wireless IC tag is demodulated by the demodulation circuit via the antenna 26. The CPU 21 takes in the demodulated response and returns it to the control system. Further, the CPU 21 can switch the antennas 26, 27, 28, and 29 used for communication with the wireless IC tag by switching the antenna changeover switch 25 of the antenna unit.

  The wireless IC tag reader of the present invention includes an address counter, an antenna counter, a wireless IC tag detection flag, and a data storage buffer inside the CPU. The address counter stores a “data address value” of the wireless IC tag read by the wireless IC tag reader. The antenna counter stores an “antenna number” used for reading the wireless IC tag. The wireless IC tag detection flag is a flag indicating that the wireless IC tag is detected by the currently used antenna, and is reset every time the antenna to be used is switched. The data storage buffer is an area for temporarily storing “data” read from the wireless IC tag.

  As shown in FIG. 2, upon receiving a data read command from the control system, the wireless IC tag reader “sets an address counter” and “resets an antenna counter”. Next, the switch of the antenna unit is switched, and the antenna used for reading the wireless IC tag is set to the antenna indicated by the antenna counter. A command to the wireless IC tag is output from the set antenna, and the data of the wireless IC tag is read. When the data read command transmission is successful and the response data from the wireless IC tag is acquired, the wireless IC tag reader “sets the wireless IC tag detection flag” and “stores the response data in the buffer”. Thereafter, the address counter is checked, and when “address counter exceeds the specified number”, “read data” stored in the buffer is returned to the control system. If the address counter does not exceed the specified number, the address counter is incremented and the process returns to the data reading process.

  In the data reading process shown in FIG. 3, the wireless IC tag detection flag is checked when there is no response from the wireless IC tag. (1) If the wireless IC tag detection flag is set, antenna switching processing is performed. In the antenna switching process, the antenna counter is first checked. If the specified number of antenna counters is not exceeded, the antenna counter is incremented and the wireless IC tag detection flag is reset, and the process returns to the antenna set. (2) If the wireless IC tag detection flag is not set or if the antenna counter exceeds the specified number, “data reading failure” occurs, and the control system is notified that the wireless IC tag data reading has failed. .

  The mobile body reading system shown in FIG. 4 functions as a part of a warehouse entry management system. A package 14 to be stored in the warehouse is attached with a wireless IC tag 11 for identification, and is transported into the warehouse by a conveyor 15. Antennas 52, 53, 54, and 55 are disposed along the conveyor 15 along the moving path of the moving body. Each antenna is connected to the wireless IC tag reader 51. The wireless IC tag reader 51 is connected to the control system 56. A moving body detection sensor 57 is connected to the control system 56 and installed in front of the antenna 52. The moving body detection sensor 57 detects that the load 14 has been conveyed.

  The load 14 is transported into the warehouse by the conveyor 15. When the moving body detection sensor 57 detects the load 14, it sends a detection signal to the control system 56. The control system 56 that has received the detection signal transmits a command for reading the identification data stored in the wireless IC tag 11 to the wireless IC tag reader 51. The wireless IC tag reader 51 that has received the command from the control system 56 sets the address counter and resets the antenna counter. The antennas are assigned antenna numbers 1, 2, 3, and 4 in order from the antenna 52. When the antenna counter is reset, it becomes a signal of 1, indicating the antenna 52.

  Next, the switch is switched according to the antenna counter, and the antenna 52 is set to be used. The wireless IC tag reader 51 transmits a data read command to the wireless IC tag 11 via the set antenna 52. If the wireless IC tag 11 is within the reading range of the antenna 52 at the time of transmission, response data is returned from the wireless IC tag 11. When receiving the response data, the wireless IC tag reader 51 sets a wireless tag IC detection flag and stores the response data in the buffer.

  Further, the wireless IC tag reader 51 checks the address counter to confirm whether the designated number of data has been read. If the data does not reach the specified number, the address counter is incremented (incremented) and the reading process is performed again. Note that the reading process is continued until the read data reaches the designated number or until there is no response from the wireless IC tag 11.

  If there is no response from the wireless IC tag 11, the wireless IC tag detection flag is checked. If the wireless IC tag detection flag is not set, the antenna counter is incremented (increased), and then the antenna Set up. This operation is based on the assumption that the load 14 is conveyed by the conveyor 15 and the wireless IC tag 11 is moved from the reading range of the antenna (A) 52 to the reading range of the antenna (B) 53. After the antenna is switched, the reading operation is continued from the address counter value.

  The identification data stored in the wireless IC tag 11 is read by repeating the above processing. By switching each antenna connected to the wireless IC reader 51 according to the movement of the package, the data reading range can be expanded. Further, the data reading range can be expanded by replacing the antenna unit with another unit to which more antennas can be connected. Furthermore, the reading range can be easily expanded without requiring any changes to the control system.

  As described above, the wireless IC tag reader whose reading range is expanded (high-speed reading is enabled) according to the present invention and the highly reliable mobile body using the wireless IC tag and the wireless IC tag reader that do not require complicated control. A reading system can be provided.

1 is a block diagram showing a configuration of a wireless IC tag reader of the present invention. 5 is a flowchart for reading identification data stored in the wireless IC tag of the present invention. 4 is a flowchart of antenna switching in the wireless IC tag of the present invention. The perspective view which showed the outline of the mobile body reading system of this invention. The perspective view which shows the concept of the physical distribution management system which manages the warehousing and delivery of a prior art example.

Explanation of symbols

11 Wireless IC tag 12 Wireless IC tag reader 13 Antenna 14 Luggage 15 Conveyor 21 CPU
22 modulation circuit 23 demodulation circuit 24 interface 25 antenna changeover switch 26, 27, 28, 29 antenna 30 antenna unit 51 wireless IC tag reader 52 antenna (A)
53 Antenna (B)
54 Antenna (C)
55 Antenna (D)
56 Control system 57 Moving object detection sensor

Claims (4)

  A wireless IC tag reader having a plurality of antennas for wirelessly reading data stored in a wireless IC tag attached to a mobile body, wherein the data stored in the wireless IC tag is stored using one of the antennas. During the reading operation, when the wireless IC tag cannot be detected depending on one of the antennas, the reading operation is interrupted and switched to other antennas in the plurality of antennas according to a predetermined order. A wireless IC tag reader having a function of searching for a wireless IC tag that can no longer be detected and restarting the reading operation.   It comprises an interface with an external control system, a modulation circuit, a demodulation circuit, a changeover switch and an antenna unit having a plurality of antennas, and the CPU stores an address counter, an antenna counter, a wireless IC tag detection flag, and data storage When the CPU receives a data read command from the control system, the CPU sets an address counter to reset the antenna counter, switches the changeover switch, and uses the antenna for reading the wireless IC tag. Is set to the antenna indicated by the antenna counter, a command is output from the set antenna to the wireless IC tag, the data of the wireless IC tag is read, the data read command transmission is successful, and the wireless IC tag Response data If acquired, the wireless IC tag detection flag is set, response data is stored in the buffer, then the address counter is checked, and if the address counter exceeds the specified number, the buffer stores the response data. The stored read data is returned to the control system, and when the address counter does not exceed a specified number, the address counter is incremented and a flow is returned to the data read process. The wireless IC tag reader according to 1.   It includes an interface with an external control system, a CPU, a modulation circuit, a demodulation circuit, a changeover switch, and an antenna unit having a plurality of antennas. The CPU includes an address counter, an antenna counter, and a wireless IC tag detection flag. A data storage buffer is included, and the CPU checks a wireless IC tag detection flag when there is no response from the wireless IC tag. If the wireless IC tag detection flag is set, an antenna switching process is performed. In the antenna switching process, first, an antenna counter is checked. If the specified number of antenna counters has not been exceeded, the antenna counter is incremented and the wireless IC tag detection flag is reset to the antenna set. Return, the wireless IC tag detection flag is set If not, or if the antenna counter exceeds a specified number, data reading fails, and a flow is executed to notify the control system that data reading of the wireless IC tag has failed. The wireless IC tag reader according to claim 1.   In a mobile body reading system configured by using a wireless IC tag reader having a plurality of antennas for wirelessly reading data stored in a wireless IC tag attached to a mobile body, the wireless IC tag is attached to the mobile body reading system. Each antenna is installed in the wireless IC tag reader along the moving path of the moving body, and the wireless body is attached to the moving body from each antenna of the wireless IC tag reader installed along the moving path. Start reading IC tag data, and when the mobile object moves from the reading range of the antenna with each antenna and the wireless IC tag cannot be detected during the data reading operation, it is adjusted to the movement. The antennas are sequentially switched to perform a reading operation, and the wireless unit attached to the moving body Mobile reading system, characterized in that by enlarging the reading range of the C-tag.

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