Vehicle locating system using GPS

• US 20050128140A1
• Filed: 12/16/2003
• Published: 06/16/2005
• Est. Priority Date: 12/16/2003
• Status: Active Grant

• Current Assignee: Lear Corporation
• Original Assignee: Lear Corporation
• Inventors: King, Ronald O., Luo, Yi, Tang, Oingfeng, Lemense, Thomas J.
• Granted Patent: US 7,145,507 B2
• Time in Patent Office: Days
• US Class Current: 342/357.340
• CPC Class Codes: B60R 25/00 Fittings or systems for preventing or indicating unauthorised use or theft of vehicles locks for vehicles E05B77/00-E05B85/00
• CPC Class Codes: G01S 19/25 involving aiding data received from a cooperating element, e.g. assisted GPS
• CPC Class Codes: G01S 19/34 Power consumption
• CPC Class Codes: G01S 2205/002 for traffic control, mobile tracking, guidance, surveillance or anti-collision
• CPC Class Codes: G01S 5/0009 Transmission of position information to remote stations involving assistance data G01S5/0236

Abstract

A vehicle locating system for directing a user to a remotely-located vehicle comprises a vehicle-mounted location unit and a personal fob. The vehicle-mounted location unit includes a first global positioning receiver for receiving satellite location signals which operates at a duty cycle sufficient to maintain predetermined aiding data. The vehicle-mounted location unit processes vehicle location data and further includes a first local data transceiver for transmitting the predetermined aiding data. The portable fob includes a second global positioning receiver for receiving the satellite location signals, wherein the second global positioning receiver operates substantially only when the user initiates a request for directions to the vehicle. The portable fob further includes a second local data transceiver for receiving the predetermined aiding data from the first local data transceiver. The portable fob processes fob location data in response to the predetermined aiding data.

Claims

1. A vehicle locating system for directing a user to a remotely-located vehicle, comprising:

a vehicle-mounted location unit including a first global positioning receiver for receiving satellite location signals, wherein said first global positioning receiver operates at a duty cycle sufficient to maintain predetermined aiding data, wherein said vehicle-mounted location unit processes vehicle location data, and wherein said vehicle-mounted location unit further includes a first local data transceiver for transmitting said predetermined aiding data; and

a portable fob including a second global positioning receiver for receiving said satellite location signals, wherein said second global positioning receiver operates substantially only when said user initiates a request for directions to said vehicle, wherein said portable fob further includes a second local data transceiver for receiving said predetermined aiding data from said first local data transceiver, and wherein said portable fob processes fob location data in response to said predetermined aiding data.

2. The vehicle locating system of claim 1 wherein said fob location data is transmitted from said second local data transceiver to said first local data transceiver, wherein said vehicle-mounted location unit determines a bearing in response to said fob location data and said vehicle location data, and wherein said bearing is transmitted from said first local data transceiver to said second local data transceiver.

3. The vehicle locating system of claim 2 wherein said portable fob further includes an electronically-controlled display for displaying said bearing.

4. The vehicle locating system of claim 1 wherein said portable fob further includes a dedicated GPS baseband processor for processing said fob location data.

5. The vehicle locating system of claim 4 wherein said portable fob further includes a hardware correlator for processing said fob location data.

6. The vehicle locating system of claim 1 wherein said aiding data is comprised of satellite ephemeris data.

7. The vehicle locating system of claim 1 wherein said aiding data is comprised of satellite clock data.

8. The vehicle locating system of claim 1 wherein said aiding data is comprised of satellite Doppler data.

9. The vehicle locating system of claim 1 wherein said fob location data comprises geographic coordinates.

10. The vehicle locating system of claim 1 wherein said fob location data comprises pseudo-range data.

11. A method of directing a user to a remotely-located vehicle, wherein said user carries a portable fob communicating with a vehicle-mounted location unit, said method comprising the steps of:

periodically receiving GPS signals from a fleet of GPS satellites in said vehicle-mounted location unit;

maintaining predetermined aiding data in said vehicle-mounted location unit in response to said GPS signals;

initiating a request at said portable fob for directions to said vehicle;

transmitting said predetermined aiding data to said portable fob in response to said request;

receiving GPS signals from said fleet of GPS satellites in said portable fob in response to said request;

said portable fob processing fob location data in response to said predetermined aiding data;

transmitting said fob location data to said vehicle-mounted location unit;

said vehicle-mounted location unit determining a vehicle location;

said vehicle-mounted location unit determining bearing information in response to said vehicle location and said fob location data;

transmitting said bearing information from said vehicle-mounted location unit to said portable fob; and

displaying said bearing information to said user.

12. The method of claim 11 wherein said predetermined aiding data comprises satellite ephemeris data.

13. The method of claim 11 wherein said predetermined aiding data comprises satellite clock data.

14. The method of claim 11 wherein said predetermined aiding data comprises satellite Doppler data.

15. The method of claim 11 wherein said step of initiating a request is comprised of activating a predetermined control element on said portable fob.

16. The method of claim 11 wherein said transmitting steps utilize respective UHF transceivers in said portable fob and said vehicle-mounted location unit.

17. The method of claim 11 wherein said fob location data comprises geographic coordinates.

18. The method of claim 11 wherein said fob location data comprises pseudo-range data.

19. The method of claim 11 wherein said bearing information comprises a direction heading.

20. The method of claim 11 wherein said bearing information comprises a direction heading and a range.