GNSS METHOD AND RECEIVER WITH CAMERA AID

• US 20100250133A1
• Filed: 12/11/2008
• Published: 09/30/2010
• Est. Priority Date: 12/11/2007
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Buros, Julien
• Granted Patent: US 8,374,786 B2
• Time in Patent Office: Days
• US Class Current: 701/216
• CPC Class Codes: G01S 19/485 whereby the further system is an optical system or imaging system

Abstract

A method of computing navigation information in a portable device comprising a GNSS receiver arranged to receive navigation signals from a plurality of navigation satellites, and a GNSS processor to extract a GNSS position information from said navigation signals. The GNSS receiver is also arranged to obtain image data from a camera module. The method comprises the steps of: deriving a set of position information from the camera module; providing the camera-derived position information to a navigation processor; using said set of camera-derived position information and said navigation signals, to generate a position fix of the GNSS receiver; computing navigation information based on said generated position fix.

Claims

1. A method of computing navigation information in a portable device (101), said device (101) comprising a GNSS receiver (104), wherein said GNSS receiver (104) is arranged to receive navigation signals (112) from a plurality of navigation satellites, and comprises a GNSS processor (105), to extract a GNSS position information from said navigation signals (112), said GNSS receiver (104) being further arranged to obtain data from a camera module (102), the method comprising the steps of:

deriving a set of position information (205) from said camera module (102);

providing said set of camera-derived position information to a navigation processor;

using said set of camera-derived position information and said navigation signals, to generate a position fix of the GNSS receiver (104);

computing navigation information based on said generated position fix.

2. The method of claim 1, wherein said set of camera-derived position information is obtained from a sequence of images recorded by said camera module (102), and comprising a step of estimating a motion of the receiver from said sequence of images.

3. The method of any of the preceding claims, wherein a dead-reckoning position estimation mode is acknowledged upon consistency of said set of camera-derived position information with a uniform motion of said GNSS receiver (104).

4. The method of any of the previous claims, further comprising a step of restricting a search space for the acquisition of said navigation signals (112) received from said plurality of navigation satellites based on said set of camera-derived position information.

5. The method of any of the previous claims, wherein the use of said set of camera-derived position information in said navigation processor is selectively activated (204) when the reception of said navigation signals (112) from said plurality of navigation satellites is poor or absent.

6. The method of any of the previous claims, further comprising a step of recognizing a landmark feature in said image data from said camera module (102), wherein said step of deriving said set of camera-derived position information (205) from the camera module consists in retrieving previously known position of said landmark feature.

7. The method of the previous claim, wherein the step of recognizing a landmark feature is only performed when said GNSS receiver (104) is turned on, the landmark feature being included in a previous image taken by said camera module (102) while said GNSS receiver is turned off.

8. The method of any of the previous claims, wherein said step (205) of deriving a set of position information from said camera module (102) includes power management features.

9. The method of any of the previous claims, further comprising a step of calibration (203) of said set of camera-derived position information.

11. A computer program product for carrying out the steps of any of the previous claims.

12. A device for camera-assisted GNSS navigation, comprising a camera module (102) and a GNSS module (104) which are connected through an interface (107) to a navigation backup module (111) used by a navigation software (110) carrying the steps of any of the claims 1 to 10.

13. The device of claim 12, said navigation backup module (111) further comprising a sensor management module (108) for managing sensors (103,106) of said camera module (102) and said GNSS module (104).

14. The device of claim 12 or 13, wherein said navigation processor is said GNSS processor (105).

10. The method of claim 10, wherein said step of calibration is performed through coupling (206) to satellite-based position information derived from said navigation signals (112) received from said plurality of navigation satellites.