RFID LOCATION SYSTEMS AND METHODS

• US 20150057919A1
• Filed: 06/16/2014
• Published: 02/26/2015
• Est. Priority Date: 12/18/2006
• Status: Abandoned Application

• Current Assignee: Tally Surgical, Inc.
• Original Assignee: Radiofy, LLC
• Inventors: Shoarinejad, Kambiz, Soltan, Maryam, Moshfeghi, Mehran
• Application Number:
  US14/305,361
• Publication Number:
  US 20150057919A1
• Time in Patent Office: Days
• US Class Current: 701/409
• CPC Class Codes: G01S 1/08 Systems for determining direction or position line
• CPC Class Codes: G01S 13/06 Systems determining position data of a target
• CPC Class Codes: G01S 13/75 using transponders powered from received waves, e.g. using passive transponders , or using passive reflectors
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G01S 19/13 Receivers
• CPC Class Codes: G01S 7/003 Transmission of data between radar, sonar or lidar systems and remote stations
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 64/006 with additional information processing, e.g. for direction or speed determination

Abstract

Embodiments of the present invention include radio frequency identification location systems and methods. In one embodiment, RF signals are transmitted from one or more RFID readers, and in accordance therewith, backscattered signals are received from a tag to be located. A plurality of measured position parameters are used to determine a location of the tag. In one embodiment, one reader may transmit and three readers may receive signals to determine the position of a tag. In other embodiments, multiple readers may transmit and receive. In another embodiment, one reader may transmit from different positions to locate a tag. Embodiments of the invention may be used to track a moving tag. A reader'"'"'s position may be determined using GPS, reference tags, or the reader may be positioned in a known location. A map may be provided to a user to display the location or movement of a tag or a corresponding item.

Claims

1-88. -88. (canceled)

89. A method of locating radio frequency identification (RFID) tags, the method comprising:

transmitting a radio frequency (RF) signal from a first RFID reader at a first location;

transmitting an RF signal from said first RFID reader at a second location;

transmitting an RF signal from a second RFID reader at a third location, wherein the first, second, and third locations are different locations;

receiving signals backscattered off a tag from the RF signals transmitted from the first RFID reader at the first and second locations and from the second RFID reader at the third location;

extracting at least one measured position parameter from each received signal backscattered off the tag; and

calculating a location of the tag using the extracted measured position parameters.

90. The method of claim 89 further comprising transmitting from a third RFID reader at a fourth location different from the first, second, and third locations, wherein the receiving further comprises receiving a signal backscattered off the tag from the RF signal transmitted from the third RFID reader, wherein the extracting further comprises extracting at least one measured position parameter from the signal backscattered off the tag from the RF signal transmitted from the third RFID reader.

91. The method of claim 89 further comprising transmitting the measured position parameters corresponding to the signals backscattered off the tag to a server to determine the location of the tag by the server.

92. The method of claim 89, wherein the RF signal transmitted from the RFID readers at each of the first, second, and third locations is transmitted at a single frequency.

93. The method of claim 89 further comprising receiving measured position parameters for the signals backscattered off the tag and received at each of the first, second, and third locations at the first RFID reader, and determining the location of the tag by the first RFID reader.

94. The method of claim 89 further comprising receiving each of the first and second locations at the first RFID reader.

95. The method of claim 89 further comprising storing one or more locations corresponding to the first RFID reader.

96. The method of claim 89 further comprising determining one or more of the first, second, and third locations using a global positioning system.

97. The method of claim 89, wherein the RF signal is transmitted by an RFID reader different from an RFID reader that receives the signal backscattered from the tag.

98. The method of claim 89, wherein the measured position parameters comprise at least one of a power of the signal backscattered from the tag, an angle of arrival of the signal backscattered from the tag, a time difference of arrival of the signal backscattered from the tag, and a phase of the signal backscattered from the tag.

99. The method of claim 98, wherein two or more different measured position parameters are extracted from each signal backscattered from the tag and used to determine the location of the tag.

100. The method of claim 98, wherein the first RFID reader transmits a plurality of RF signals from each of the first and second locations and the second RDIF reader transmits a plurality of RF signals from the third location, wherein the first and second RFID readers receive a plurality of corresponding signals backscattered off the tag from each transmitted signal, wherein the first and second RFID readers extract measured position parameters from the received backscattered signals.

101. The method of claim 89 further comprising determining raw location parameters for the tag to be located, the raw location parameters representing the location of the tag as latitude and longitude, Cartesian coordinates, Polar coordinates, or as one or more vectors.

102. The method of claim 101 further comprising generating mapped position information from the raw location parameters.

103. The method of claim 89 further comprising associating a map image with the location of the tag and displaying the map image to a user.

104. The method of claim 89, wherein the first RFID reader is embedded in a mobile device.

105. A device for locating radio frequency identification (RFID) tags, the device comprising:

a radio frequency (RF) signal transmitter for transmitting RF signals to a tag;

a receiver for receiving signals backscattered off the tag;

the device configured to;

transmit an RF signal from the transmitter at a first location;

transmit an RF signal from the transmitter at a second location;

receive, at the receiver, signals backscattered off a tag from the RF signals transmitted at the first and second locations; and

receive, at the receiver, signals backscattered off the tag from RF signals transmitted at a third locations from another, wherein the first, second, and third locations are different locations;

extract at least one measured position parameter from each received signal backscattered off the tag; and

calculate a location of the tag using the extracted measured position parameters.

106. The device of claim 105 further configured to transmit the measured position parameters corresponding to the signals backscattered off the tag to a server to determine the location of the tag by the server.

107. The device of claim 105, wherein the RF signal transmitted at each of the first, second, and third locations is transmitted at a single frequency.

108. The device of claim 105 further comprising receiving each of the first and second locations at the device.

109. The device of claim 105 further comprising storage, the device further configured to store the first and second locations in the storage of the device.

110. The device of claim 105 further comprising a global positioning system (GPS), the device further configured to determine one or more of the first and second locations using a global positioning system.

111. The device of claim 105, wherein the measured position parameters comprise at least one of a power of the signal backscattered from the tag, an angle of arrival of the signal backscattered from the tag, a time difference of arrival of the signal backscattered from the tag, and a phase of the signal backscattered from the tag.

112. The device of claim 111, wherein two or more different measured position parameters are extracted from each signal backscattered from the tag and used to determine the location of the tag.

113. The device of claim 111, wherein the device transmits a plurality of RF signals from each of the first and second locations and the other device transmits a plurality of RF signals from the third location, wherein the device receives a plurality of corresponding signals backscattered off the tag from each transmitted signal, wherein the device is further configured to extract measured position parameters from the received backscattered signals.

114. The device of claim 105 further configured to determine raw location parameters for the tag to be located, the raw location parameters representing the location of the tag as latitude and longitude, Cartesian coordinates, Polar coordinates, or as one or more vectors.

115. The device of claim 114 further configured to generate mapped position information from the raw location parameters.

116. The device of claim 105 further configured to associate a map image with the location of the tag and displaying the map image to a user.