System and method for estimating mobile wireless unit position in a localized area

• US 8,145,235 B2
• Filed: 06/16/2006
• Issued: 03/27/2012
• Est. Priority Date: 06/17/2005
• Status: Active Grant

• Current Assignee: Fondazione Torino Wireless, Istituto Superiore Mario Boella Sulle Tecnologie Dell'Informazione e Delle Telecomunicazioni
• Original Assignee: Fondazione Torino Wireless, Instituto Superiore Mario Boella Sulle Tecnologie Del'Informazione E Delle Telecomunicati
• Inventors: Di Gangi, Michele, Ferrari, Aleck, Prato, Roberto, Badella, Monica, Forno, Fabio, Carlevato, Andrea, Valera, Loris, Tessitore, Luca, Malnati, Giovanni, Titli, Andrea Pietro, Portelli, Giuseppe
• Primary Examiner(s): Cordero, Marivelisse Santiago
• Assistant Examiner(s): COSME, NATASHA W
• Application Number:
  US11/917,687
• Publication Number:
  US 20080214203A1
• Time in Patent Office: 2,111 Days
• Field of Search: 455/456
• US Class Current: 455/456.1
• CPC Class Codes: G01C 21/206 specially adapted for indoor navigation
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location

Abstract

A local positioning system comprises a plurality of sensor elements that may communicate with mobile units in a wireless fashion. The responsiveness of the mobile units is measured by yes/no answers and averaged so as to provide a measure of the distance of a mobile unit to a specified sensor element. Based on this measure and the known positions of the sensor element, the position of the mobile unit is estimated, for instance by a model of ideal springs.

Claims

1. A local positioning system, comprising:

one or more averaging units configured to receive multiple sequences of digital values that represent whether or not acknowledgements from a mobile device to respective inquiries from respective transmitters of a plurality of transmitters were received and to generate an averaged value for each of said sequences digital values; and

a control unit communicatively coupled to said one or more averaging units, configured to receive said averaged values from said one or more averaging units, said control unit being further configured to estimate a position of said mobile device based at least in part on said averaged values and on defined locations associated with the transmitters of the plurality of transmitters.

2. The local positioning system of claim 1, further comprising:

the plurality of transmitters, configured to transmit said inquiries at varying power levels.

3. The local positioning system of claim 1, wherein the one or more averaging units are further configured to receive information that correlates the sequences of digital values to the respective transmitters.

4. The local positioning system of claim 3, wherein said acknowledgements include identifiers of the mobile device, and said plurality of sequences of digital values include said identifiers.

5. The local positioning system of claim 3, wherein said control unit is further configured to receive said sequences of digital values via a wireless channel.

6. The local positioning system of claim 1, wherein said control unit is further configured to receive said sequences of digital values via a cable connection.

7. The local positioning system of claim 1, wherein said sequences of digital values are sequences of binary values.

8. The local positioning system of claim 1, wherein said one or more averaging units are configured to low pass filter the sequences of digital values.

9. The local positioning system of claim 1, wherein said control unit is further configured to estimate another position of another mobile device.

10. The local positioning system of claim 1, further comprising an interface configured to provide said estimated position to a location-based service.

11. A method of estimating a location of a wireless device, comprising:

transmitting, from a plurality of transmitters located at defined locations of a first area, respective sequences of inquiries;

receiving, from the wireless device, acknowledgements to at least some of the inquiries transmitted from at least some of the transmitters;

determining, for each sequence of inquiries, a responsiveness of the wireless device to the particular sequence of inquiries based at least in part on a sequence of digital values that represents whether or not acknowledgements were received for each inquiry of the particular sequence of inquiries, including;

generating, for each sequence of inquiries, an averaged value based at least in part on averaging the digital values of the particular sequence of digital values; and

estimating the location of the wireless device based at least in part on the averaged values and the defined locations.

12. The method of claim 11, wherein said transmitting the respective sequences of inquiries includes:

transmitting a first inquiry of a first sequence of inquiries at a first transmit power; and

transmitting a second inquiry of the first sequence of inquiries at a second transmit power, wherein the first transmit power is different than the second transmit power.

13. The method of claim 11, wherein the sequences of digital values are sequences of binary values.

14. The method of claim 11, wherein said determining the responsiveness of the wireless device to the particular sequence of inquiries at a location different from the defined locations.

15. The method of claim 11, further comprising:

transmitting the sequences of digital values to a remote control unit.

16. The method of claim 11, further comprising

transmitting the sequences of digital values to a remote control unit via a wireless transmission channel.

17. The method of claim 11, wherein said estimating the location of the wireless device includes:

estimating distances of the wireless device from the defined locations based at least in art on averaged values generated from the sequence of inquires transmitted from the respective transmitters.

18. The method of claim 17, wherein said estimating the location of the wireless device is based at least in part on an ideal springs analysis.

19. The method of claim 11, further comprising:

providing the estimated location of the wireless device to a location based service.

20. The method of claim 19, further comprising:

receiving, by the location based service, the estimated location of the wireless device; and

providing, by the location based service to the wireless device, information based at least in part on the received estimated location.

21. The method of claim 20, wherein the received estimated location is indicative of entry of the wireless device into the first area.

22. The method of claim 20, wherein the provided information includes an indication of a status of the first area.

23. The method of claim 20, further comprising:

selecting the location based service from a plurality of location based services based at least in part on the estimated location of the wireless device; and

communicating, by the selected location based service, with the wireless device.

24. The method of claim 11, further comprising:

estimating another location of another less device within the first area during a predefined time period.

25. The method of claim 11, further comprising:

determining a target spatial resolution for the estimated location of the wireless device; and

selecting a quantity of transmitters to be employed as the plurality of transmitters and selecting the defined location for the selected quantity of transmitters based at least in part on the determined target spatial resolution.

26. The method of claim 25, wherein the target spatial resolution is less than approximately 10 meters.

27. The method of claim 11, wherein the transmitters include Bluetooth compatible transmitters.

28. A non-transitory computer-readable medium having instruction stored thereon for causing a device to perform operations to estimate the location of a wireless device, the operations comprising:

receiving, from a plurality of transmitters, respective sequences of digital values, wherein the sequences of digital values represent whether or not acknowledgements to respective inquiries from respective transmitters of the plurality of transmitters were received from the wireless device;

generating averaged values for the sequences of digital values based at least in part on averaging the sequences of digital values; and

estimating the location of the wireless device based at least in part on the averaged values.

29. The non-transitory computer-readable medium of claim 28, wherein said averaging the sequences of digital values is based at least in part on which of multiple power levels were employed by the transmitters for transmission of the inquires.

30. The non-transitory computer-readable medium of claim 28, wherein said estimating the location of the wireless device includes:

estimating distances of the wireless device from the transmitters based at least in part on the generated averaged values.

31. The non-transitory computer-readable medium of claim 28, wherein the operations further comprise:

providing the estimated location of the wireless device to a location based service.

32. The non-transitory computer-readable medium of claim 28, wherein said averaging the sequences of digital values includes low-pass filtering the sequences of digital values.

33. A system for estimating the location of a wireless device, comprising:

means for receiving, from a plurality of transmitters, respective sequences of digital values, wherein the sequences of digital values represent whether or not acknowledgements to respective inquiries from respective transmitters of the plurality of transmitters were received from the wireless device;

means for generating averaged values for the sequences of digital values based at least in part on averaging the sequences of digital values; and

means for estimating the location of the wireless device based at least in part on the averaged values.

34. The system of claim 33, further comprising:

means for providing the estimated location of the wireless device to a location based service.

35. The system of claim 33, wherein the means for generating averaged values includes:

means for low-pass filtering the sequences of digital values.