Method for measuring location of radio frequency identification reader by using beacon

• US RE47,013 E1
• Filed: 01/12/2016
• Issued: 08/28/2018
• Est. Priority Date: 05/23/2007
• Status: Active Grant

• Current Assignee: SK Planet Co., Ltd. (SK Telecom Co., Ltd.), SK Telecom Co., Ltd.
• Original Assignee: SK Planet Co., Ltd. (SK Telecom Co., Ltd.), SK Telecom Co., Ltd.
• Inventors: Rhie, Sangwoo, Sohn, Sangmok, Jeong, Soonjae, Jeon, Jaesic, Yoon, Youngshin, Kim, Youngil, An, Sunshin, Kim, Sungjun, Ji, Youngmin, Lee, Joosik
• Primary Examiner(s): WHITTINGTON, KENNETH
• Application Number:
  US14/993,275
• Time in Patent Office: 959 Days
• Field of Search: 3242072, 32420723, 32420724, 342450, 342458, 342461, 4554561, 4554563, 4554566, 340572, 3405721, 3405724, 3405391, 34053913
• CPC Class Codes: G01S 1/68 Marker, boundary, call-sign, or like beacons transmitting signals not carrying directional information
• CPC Class Codes: G01S 11/06 using intensity measurements
• CPC Class Codes: G01S 5/0226 Transmitters
• CPC Class Codes: G01S 5/0294 Trajectory determination or predictive filtering, e.g. target tracking or Kalman filtering
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location

Abstract

The present invention relates to a method for measuring a location of a radio frequency identification (RFID) reader by using beacons, and an RFID system for measuring a location of a moving RFID reader in an RFID system comprising: a plurality of beacon devices for emitting beacons; an RFID tag for transmitting pre-stored information by using radio frequency identification; and an RFID reader for calculating a current location using a plurality of at least three beacons wherein the RFID reader receives the plurality of beacons from the plurality of beacon devices while moving, and receiving the information from the RFID tag by using the radio frequency identification. According to the present invention, it is possible to increase the accuracy of the location measurement of a moving RFID reader in an RFID system because the location of the RFID reader is measured in consideration of propagation environments.

Claims

1. A radio frequency identification (RFID) system for measuring a location of an RFID reader by using a beacon short-range wireless communication system, the short-range wireless communication system comprising:

a plurality of beacon devices transmitters, each of which is fixed at a reference location and comprises an antenna, a processor and configured to create a database of a memory having computer executable instructions stored thereon that, when executed by the processor, cause each of the beacon transmitters to;

emit a beacon, wherein each of the beacon transmitters stores information about signal intensities to distances by measuring of the beacon, the information about the signal intensities of the beacon according to distance distances having been obtained based on a propagation environment and emit the beacon which around each of the beacon transmitters, wherein the beacon includes information about the reference location of each beacon device of the plurality of the beacon transmitters and the information about the signal intensities to distances from each beacon device; and

an RFID reader configured to receive the beacona means for

receiving beacons from each of the plurality of beacon devices transmitters,

measure a signal intensity of each received beacon, determine a distance from each beacon device by analyzing the measured signal intensity on the basis of theextracting information about signal intensities to distances included in the received beacon and to calculate a current location thereof by using bothfrom the received beacons,

measuring signal intensities of the received beacons,

determining distances from the respective beacon transmitters based on the measured signal intensities and the information about the signal intensities to distances, and

calculating the location of the means based on reference location locations of the plurality of beacon transmitters and the determined distance distances from each beacon device the plurality of beacon transmitters,

wherein the RFID reader calculates means is configured to calculate the current location of the means through a triangulation method using based on the reference location locations of each beacon device the plurality of beacon transmitters and the determined distance distances from each beacon device the beacon transmitters.

2. The system as claimed in claim 1, wherein the RFID reader receives the plurality of beacons from at least beacon transmitters include three beacon devices among the plurality of beacon devices or more beacon transmitters.

3. The system as claimed in claim 2, wherein, when receiving the plurality of beacons from said at least more than three beacon devices transmitters, the RFID reader means calculates the current location by of the means using three beacons having relatively higher signal intensities among the plurality of received beacons.

4. The system as claimed in claim 1, wherein the RFID reader calculates means is configured to store the location of the means at a first moment as a pre-moving first location and the location and a post-moving thereof at a second moment as a second location, and calculates the first moment being different from the second moment, and calculate a speed and a moving direction of the means from the pre-moving first location to the post-moving second location, based on a distance from the first location to the second location and a time difference between the first moment and the second moment.

5. The system as claimed in claim 4, wherein the RFID reader measures a movement time from the pre-moving location to the post-moving location, calculates a distance from the pre-moving location to the post-moving location, and then calculates a ratio of the distance to the time as the speed means is configured to calculate the moving direction by calculating a vector from the first location to the second location.

6. The system as claimed in claim 4, wherein the RFID reader calculates the direction by calculating a vector from the pre-moving location to the post-moving location 1, wherein the short-range wireless communication system is a radio frequency identification (RFID) system, and the beacon transmitters are beacon devices.

7. A method for calculating a current location of a radio frequency identification (RFID) reader in an RFID system by using a beacon of a beacon device in a plurality of beacon devices each of which is fixed at a reference location and configured to create a database of information about signal intensities to distances by measuring signal intensities of the beacon according to distance based on a propagation environment and emit the beacon which includes information about the reference location of each beacon device and the information about signal intensities to distances from each beacon device the location of the means using the system of claim 1, the method comprising the steps of:

(a) receiving a plurality of beacons from the plurality of beacon devices transmitters fixed at the reference locations respectively;

extracting the information about the signal intensities to distances from the received beacons;

(b) measuring signal intensities of the plurality of beacons; and

(c) received beacons;

determining distances from the plurality of beacon devices by analyzing the measured signal intensities on the basis of the information about signal intensities to distances included in the plurality of received beacons respective beacon transmitters based on the measured signal intensities and the information about the signal intensities to distances; and

(d) calculating the location of each beacon device by using the reference locations of the plurality of beacon devices and the determined distances in step (c) from the plurality of beacon devices the means through a triangulation method based on the reference locations of the beacon transmitters and the determined distances from the beacon transmitters.

8. The method as claimed in claim 7, where step (c) comprising the steps of:

(c1) identifying information about the reference locations of the plurality of beacon devices, which is included in the plurality of beacons, by analyzing the plurality of beacons; and

(c2) calculating the location through a triangulation method using the reference locations of the plurality of beacon devices and the determined distances from the plurality of beacon devices further comprising;

storing the location of the means at a first moment as a first location;

storing the location thereof at a second moment as a second location, the first moment being different from the second moment; and

calculating a speed and a moving direction of the means from the first location to the second location, based on a distance from the first location to the second location and a time difference between the first moment and the second moment.

9. The method as claimed in claim 7, further comprising, after step (c), the steps of:

(d) moving the current location to a next location; and

(e) calculating a moving speed and a moving detection from the current location to the next location wherein the plurality of beacon transmitters are beacon devices.

10. A method for calculating a current the location of a radio frequency identification (RFID) reader the means of claim 1, the method comprising the steps of:

receiving a beacon at the RFID reader beacons from each of at least three beacon devices a plurality of beacon transmitters which are disposed near the RFID reader, each beacon including first means, wherein the beacons include information about a reference location locations of each beacon device and second the beacon transmitters and information about signal intensities to distances from each beacon device, respectively;

retrieving at the RFID reader the first information and the second information from each received beaconextracting information about the signal intensities to distances from the received beacons;

measuring at the RFID reader a signal intensity of each received beacon signal intensities of the received beacons;

determining at the RFID reader a distance from each beacon device by analyzing the measured signal intensity on the basis of the retrieved second information distances from the respective beacon transmitters based on the measured signal intensities and the information about the signal intensities to distances; and

calculating at the RFID reader the current location by using both the retrieved first information about the reference location and the determined distance,

wherein the each beacon device has a database of information about signal intensities to distances by measuring signal intensities of the beacon according to distance based on a propagation environment of the means through a triangulation method based on the reference locations of the beacon transmitters and the determined distances from the beacon transmitters.

11. The method as claimed in claim 10, wherein the beacon transmitters are beacon devices.

12. The method as claimed in claim 10, wherein the beacon includes at least one of an RF signal, a Zigbee signal and a Bluetooth signal.

13. The method as claimed in claim 1, wherein the beacon includes at least one of an RF signal, a Zigbee signal and a Bluetooth signal.

14. The system as claimed in claim 7, wherein the beacon includes at least one of an RF signal, a Zigbee signal and a Bluetooth signal.