Environmental location system

• US 6,424,916 B2
• Filed: 07/10/2001
• Issued: 07/23/2002
• Est. Priority Date: 02/10/1999
• Status: Expired due to Fees

• Current Assignee: X-Cyte Inc.
• Original Assignee: X-Cyte Inc.
• Inventors: Nysen, Paul A.
• Primary Examiner(s): NGUYEN, TAN QUANG
• Application Number:
  US09/902,073
• Publication Number:
  US 20020019702A1
• Time in Patent Office: 378 Days
• Field of Search: 701/300, 701/217, 701/302, 340/505, 340/5.61, 340/531, 340/10.42, 340/825.31, 340/825.49, 340/825.72, 342/51, 342/44
• US Class Current: 701/300
• CPC Class Codes: G01S 13/751 wherein the responder or reflector radiates a coded signal
• CPC Class Codes: G01S 13/876 Combination of several spaced transponders or reflectors of known location for determining the position of a receiver G01S13/874 takes precedence
• CPC Class Codes: G01S 15/874 Combination of several spaced transponders or reflectors of known location for determining the position of a receiver G01S15/872 takes precedence
• CPC Class Codes: G01S 7/40 Means for monitoring or calibrating
• CPC Class Codes: G01S 7/4091 during normal radar operation
• CPC Class Codes: G01S 7/52006 with provision for compensating the effects of temperature
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A system and method for determining a location. The system employs encoded information devices dispersed through the environment, each having a non-unique code associated therewith. The codes from the encoded information devices are acquired as a reading device passes nearby, and stored. The codes from a proximate set of information devices are correlated with a map or mapping relation to determine one or more consistent positions within the environment. The information devices are preferably passive acoustic wave transponders, and the mapping relation may be a pseudorandom sequence or a defined map.

Claims

1. A localization system, comprising:

(a) a receiver, for receiving a communication including an information code from a device having an associated location,

(b) a first memory, storing a plurality of communicated information codes;

(c) a second memory, storing a map relating an information code with an associated location of a device;

(d) an analyzer, for determining, based on the information in said first memory and said information in said second memory, a location of said receiver, wherein the information codes from respective receivers need not be unique to determine an unambiguous location.

2. The localization system according to claim 1, wherein said devices each comprise a radio frequency identification transponder.

3. The localization system according to claim 2, wherein said radio frequency identification transponders comprise passive backscatter transponders.

4. The localization system according to claim 3, wherein said passive backscatter radio frequency identification transponders comprise surface acoustic wave devices.

5. The localization system according to claim 1, wherein the system further receives and analyzes a geopositioning signal.

6. The localization system according to claim 1, wherein said analyzer provides an error tolerant algorithm for determining a location of the receiver in the event that one or more errors of the following types occur:

said location is altered, said receiver receives an erroneous information code, said receiver misreceives said information code, and said map is erroneous.

7. The localization system according to claim 1, wherein said analyzer computes a correlation of sets of the stored mapping information and the sets of proximate information codes to determine consistent locations in a fault tolerant manner.

8. The localization system according to claim 1, wherein the analyzer further computes a path of the system.

9. The localization system according to claim 1, further comprising a cellular communications transceiver for communicating with a remote communications device.

10. A localization system, comprising:

(a) a receiver, adapted for receiving information content signals from nearby devices having predetermined locations, the information signal from any device having an information content insufficient to uniquely identify that device, said devices being distributed in a non-sequential fashion with respect to a relation between respective information content signals and device position; and

(b) an analyzer, for analyzing a plurality of received information content signals, with respect to a map of device locations and corresponding information content signals, to determine a probable location of said receiver.

11. The localization system according to claim 10, wherein said information devices each comprise a radio frequency identification transponder.

12. The localization system according to claim 11, wherein said radio frequency identification transponders comprise passive backscatter transponders.

13. The localization system according to claim 12, wherein said passive backscatter radio frequency identification transponders comprise surface acoustic wave devices.

14. The localization system according to claim 10, wherein at least two information devices within the environment have the same information code.

15. The localization system according to claim 10, wherein the system further receives and analyzes a geopositioning signal.

16. The localization system according to claim 15, wherein said geopositioning signal provides a coarse location and said determined location provides a precise location.

17. The localization system according to claim 10, wherein said analyzer executes an algorithm for determining a probable location of said receiver, which is fault tolerant in the event that one or more errors of the following types occur:

said predetermined location is altered, said receiver receives an erroneous information code, said receiver misreceives said information code, and said map is erroneous.

18. The localization system according to claim 10, wherein the analyzer further computes a path of the system.

19. The localization system according to claim 10, further comprising a cellular communications transceiver for communicating with a remote communications device.

20. A localization system comprising:

an transponder interrogator;

a memory for storing mapping information, comprising a set of transponder codes and a respective corresponding location;

a memory for storing sets of transponder codes received by said transponder interrogator; and

an analyzer, for determining a corresponding map location for said transponder interrogator.

21. The localization system according to claim 20, wherein said transponder interrogator is adapted for mounting in a vehicle, and said transponder codes do not uniquely identify said predetermined location.

22. The localization system according to claim 20, further comprising a geopositioning system for determining a geographic position, said analyzer analyzing the transponder codes and geographic position to determine said corresponding map location.

23. The localization system according to claim 20, further comprising a cellular communication system.