VARIABLY SPACED MULTI-POINT RFID TAG READER SYSTEMS AND METHODS

• US 20120319822A1
• Filed: 03/01/2011
• Published: 12/20/2012
• Est. Priority Date: 03/01/2010
• Status: Active Grant

• Current Assignee: Innovative Timing Systems LLC
• Original Assignee: Innovative Timing Systems LLC
• Inventors: Hansen, Kurt S
• Granted Patent: US 9,504,896 B2
• Time in Patent Office: Days
• US Class Current: 340/10.1
• CPC Class Codes: A63B 2024/0025 Tracking the path or location of one or more users, e.g. players of a game
• CPC Class Codes: A63B 2225/15 with identification means that can be read by electronic means
• CPC Class Codes: A63B 2225/20 with means for remote communication, e.g. internet or the like
• CPC Class Codes: A63B 2225/54 Transponders, e.g. RFID
• CPC Class Codes: A63B 71/0616 Means for conducting or scheduling competition, league, tournaments or rankings
• CPC Class Codes: G06K 7/10356 using a plurality of antennas, e.g. configurations including means to resolve interference between the plurality of antennas
• CPC Class Codes: G06K 7/10425 the interrogation device being arranged for interrogation of record carriers passing by the interrogation device
• CPC Class Codes: G06K 7/10475 arrangements to facilitate interaction with further interrogation devices, e.g. such that at least two interrogation devices may function and cooperate in a network of such devices
• CPC Class Codes: G07C 1/24 Race time-recorders

Abstract

Systems and methods for determining a time of a passing at a reference line of an RFID tag traveling along a route and a time of lapsing of the tracked RFID tag on the route, the system have a plurality of spaced apart tag reader systems for wirelessly obtaining tag reads, wherein at least one of the tag reader systems is space apart from the reference line. The timing system receives a plurality of tag reads and determines the time of passing of the RFID at the reference ID line responsive to the plurality of received tag read messages received from the plurality of tag reader systems.

Claims

1. A timing system for determining a time of a passing at a reference line of a tracked RFID tag traveling along a route, the system comprising:

a first tag reader system having a processor, a memory, a clock, a communication interface, a radio frequency transceiver for wirelessly communicating with the RFID tag, and one or more antennas coupled to the radio frequency transceiver that are positioned at a first monitored position at a first offset distance from the reference line, the first tag reader system transmitting a first tag read request and receiving one or more first tag reads from the RFID tag, and transmitting over the communication interface a first tag read message including at least a portion of the received first tag reads;

a second tag reader system having a processor, a memory, a clock, a communication interface, a radio frequency transceiver for wirelessly communicating with the RFID tag, and one or more second antennas coupled to the second radio frequency transceiver that are positioned at a second monitored position at a second offset distance from the reference line and spaced apart from the first monitored position along the route traveled by the RFID tag, the second tag reader system transmitting a second tag read request and receiving one or more second tag reads from the RFID tag and transmitting over its communication interface a second tag read message including at least a portion of the received second tag reads; and

a timing system having a processor, a memory including storing of a tag reader normalization parameter, and a communication interface communicatively coupled to the communication interfaces of the first and second tag reader systems for receiving the transmitted first and second tag read messages, the timing system determining the time of passing of the RFID tag at the reference line responsive to the received first and second tag reads and the stored tag reader normalization parameter.

2. The system of claim 1 wherein the timing system computes an average delta time for each of the first and second tag read and determines the time of passing from the first and second computed average delta times.

3. The system of claim 2 wherein one or both of the first and second tag reader systems transmit a plurality of first and second tag reads, respectively and wherein each average time is calculated on each of the received first and second tag reads.

4. The system of claim 1 wherein the timing system is implemented integrally with at least one of the first and second tag reader systems.

5. The system of claim 1 wherein the timing system is a first timing system implemented integrally with the first tag reader system, further comprising a second timing system implemented integrally with the second tag reader system.

6. The system of claim 1 wherein the first offset distance is zero and the first monitored position is coincidental with the reference line.

7. The system of claim 1 wherein neither the first nor second offset distances are zero and neither the first or second monitored positions is coincidental with the reference line, and wherein the timing system memory includes a stored tag reader normalization parameter associated with each of the first and second offset distances, and wherein the timing system determines the time of passing of the RFID tag at the reference line responsive to the received first and second tag reads and the stored tag reader normalization parameters for the first and second offset distances.

8. The system of claim 1 wherein the RFID tag is a passive RFID tag and wherein each of the wireless transceivers of the first and second tag reader systems are configured to transmit a powering activation message and the read request message to RFID tag.

9. The system of claim 1 wherein the first and second tag read requests are continuously transmitted as pulses.

10. The system of claim 1 wherein each of the first and second tag reads includes a tag serial number of the RFID tag.

11. The system of claim 10 wherein each first and second tag read message includes a data packet having a tag reader system identifier, a tag read time, and the tag serial number, wherein the timing system determines the passing of the RFID tag response to the received tag read times.

12. The system of claim 11 wherein each first and second tag read message includes a data packet having a tag reader system identifier, and the tag serial number.

13. The system of claim 1 wherein at least one of the first and second tag reader systems includes a plurality of antennas and wherein each first and second tag read message includes a data packet having an antenna identifier that is unique to each antenna and wherein the timing system determines the time of passing of the RFID tag responsive to antenna identifiers received with each of the first and second tag read messages.

14. The system of claim 1 wherein the timing system includes a clock and wherein the timing system transmits a timing message to each of the first and second tag reader systems via the communication interfaces and wherein each of the first and second tag reader systems sets a timing of its respective clock responsive to the received timing message.

15. The system of claim 1 wherein each of the first and second tag reader systems time stamps each received tag read and generates each tag read message to include the time stamp and the received tag read in the tag read message that is transmitted.

16. The system of claim 1 wherein each of the first and second tag readers receiving a plurality of first and second tag reads from the same RFID tag, and wherein each transmits its tag read message to include a selected one of the plurality of first and second tag reads.

17. The system of claim 16 wherein the selected of each plurality of first and second tag reads is the last such tag read received.

18. A timing system for determining a time of a passing at a reference line of a tracked RFID tag traveling along a route, the system comprising:

means for wirelessly transmitting one or more first tag read requests to the RFID tag at a first tag reader system having one or more antennas positioned at a first monitored position at a first offset distance from the reference line along the route traveled by the RFID tag;

means for receiving one or more first tag reads responsive to the first tag requests wherein the first tag read includes an RFID identification number from the RFID tag responsive to the first tag read requests;

means for recording a time stamp for each received first tag read that includes a time of receipt of each first tag read;

means for transmitting one or more first tag read messages containing the RFID identification number, the time stamp, and a tag reader system identifier;

means for wireles sly transmitting one or more second tag read requests to the RFID tag at a second tag reader system having one or more antennas positioned at a second monitored position spaced apart from the first monitored position and at a second offset distance from the reference line along the route traveled by the RFID tag;

means for receiving one or more second tag reads responsive to the second tag requests wherein the second tag read include the RFID identification number from the RFID tag responsive to the second tag read requests;

means for recording a time stamp for each received second tag read that includes a time of receipt of each second tag read;

means for transmitting one or more second tag read messages containing the RFID identification number, the time stamp, and a tag reader system identifier;

means for storing a tag reader normalization parameter at a timing system;

means for receiving the transmitted first and second tag read messages;

means for calculating an average delta time for each of the first and second tag read messages based in part on the stored tag reader normalization parameter;

means for determining the time of passing of the RFID tag at the reference line responsive to the calculated average delta times for the first and second tag reads within the first and second tag read messages.

19. A timing system for determining an elapsed time of a tracked RFID tag traveling between a first and a second monitored position on a route, the system comprising:

a) for each of the first and second monitored positions;

means for wirelessly transmitting one or more first tag read requests to the RFID tag at a first tag reader system having one or more antennas positioned at a first monitored position at a first offset distance from the reference line along the route traveled by the RFID tag;

means for receiving one or more first tag reads responsive to the first tag requests wherein the first tag read include an RFID identification number from the RFID tag responsive to the first tag read requests;

means for recording a time stamp for each received first tag read that includes a time of receipt of each first tag read;

means for transmitting one or more first tag read messages containing the RFID identification number, the time stamp, and a tag reader system identifier;

means for wireles sly transmitting one or more second tag read requests to the RFID tag at a second tag reader system having one or more antennas positioned at a second monitored position spaced apart from the first monitored position and at a second offset distance from the reference line along the route traveled by the RFID tag;

means for receiving one or more second tag reads responsive to the second tag requests wherein the second tag read include the RFID identification number from the RFID tag responsive to the second tag read requests;

means for recording a time stamp for each received second tag read that includes a time of receipt of each second tag read;

means for transmitting one or more second tag read messages containing the RFID identification number, the time stamp, and a tag reader system identifier;

b) at a timing system;

means for storing a tag reader normalization parameter at a timing system;

means for receiving the transmitted first and second tag read messages;

means for calculating an average delta time for each of the first and second tag read messages based in part on the stored tag reader normalization parameter;

means for determining the time of passing of the RFID tag at the reference line responsive to the calculated average delta times for the first and second tag reads within the first and second tag read messages, wherein the determined time of passing of the first monitored position is the start of the elapsed time and the determined time of passing of the second monitored position is the end of the elapsed time; and

means for determining the elapsed time for the RFID tag traveling between the first and second monitored positions as the difference between determined time of passing of the second monitored position and determined time of passing of the first monitored position.

20. A method for determining a time of a passing at a reference line of a tracked RFID tag traveling along a route, the method comprising:

a. at a first tag reader system having one or more antennas positioned at a first monitored position at a first offset distance from the reference line along the route traveled by the RFID tag;

wirelessly transmitting one or more first tag read requests to the RFID tag;

receiving one or more first tag reads including an RFID identification number from the RFID tag responsive to the one or more of the first tag read requests;

recording a time stamp for each received first tag read that includes a time of receipt of each first tag read;

transmitting one or more first tag read messages containing the RFID identification number, the time stamp, and a tag reader system identifier;

b. second tag reader system having one or more antennas positioned at a second monitored position at a second offset distance from the reference line and spaced apart from the first monitored position along the route traveled by the RFID tag;

wirelessly transmitting one or more second tag read requests to the RFID tag;

receiving one or more second tag reads including the RFID identification number from the RFID tag responsive the at least one of the second tag read requests;

recording a time stamp for each received second tag read that includes a time of receipt of each second tag read;

transmitting one or more second tag read messages containing the RFID identification number, the time stamp, and a tag reader system identifier;

c. at a timing system;

storing a tag reader normalization parameter;

receiving the transmitted first and second tag read messages;

calculating an average delta time for each of the first and second tag read messages based in part on the stored tag reader normalization parameter;

determining the time of passing of the RFID tag at the reference line responsive to the calculated average delta times for the first and second tag reads within the first and second tag read messages.

21. The method of claim 20, further comprising:

transmitting a time synchronization message by the timing system;

receiving the time synchronization message by each of the first and second tag reader systems; and

resetting a clock associated with each of the first and second tag reader systems response to the received time synchronization messages,

wherein recording the time stamp by the first and second tag reader systems are based on the resetting of each respective clock.

22. The method of claim 20 wherein each of the first and second tag reader systems includes one or more antennas, where each tag reader performs the method comprising;

identifying each antenna having received each tag read,

wherein each tag reader generates the tag read message to include an antenna identifier for each identified antenna, and

wherein the timing system computes the average delta time for each tag read as a function of the antenna identifier.

23. The method of claim 22, further comprising at the timing system determining a position of the RFID tag relative to the first and second monitored positions and wherein determining the time of the RFID tag passing the reference line includes associating the determined position of the RFID tag relative to the first and second monitored positions.

24. The method of claim 20 wherein determining the time of the RFID tag passing the reference line includes identifying a position of the reference line relative to both the first and second monitored positions.

25. The method of claim 20 wherein the recording of the time stamp by the first tag reader is a time at a start of the elapsed time and recording a time stamp by the second tag reader is a time at an end of the elapsed time, the method of the timing system further includes computing an elapsed time for the RFID tag traveling between the first and second monitored points as the difference between determined time of passing of the second monitored point and determined time of passing of the first monitored point.