Location and motion estimation using ground imaging sensor

• US 8,725,413 B2
• Filed: 06/29/2012
• Issued: 05/13/2014
• Est. Priority Date: 06/29/2012
• Status: Active Grant

• Current Assignee: Southwest Research Institute
• Original Assignee: Southwest Research Institute
• Inventors: Kozak, Kristopher C., Alban, Marc C., Slocum, Samuel E.
• Primary Examiner(s): Marc, McDieunel
• Application Number:
  US13/537,776
• Publication Number:
  US 20140005932A1
• Time in Patent Office: 683 Days
• Field of Search: 701/300, 701/400, 701/454, 701/455, 701/468, 701/491, 701/500, 701/501, 701/516, 701/523, 382/100, 382/106, 382/154, 382/190, 382/201, 382/284, 382/285, 382/294, 382/305, 340/990, 340/995.19, 340/995.27, 342/357.34, 342/457, 342/458, 358/448, 358/452, 356/3, 356/601, 348/143
• US Class Current: 701/446
• CPC Class Codes: G01C 21/005 with correlation of navigation data from several sources, e.g. map or contour matching G01C21/30 takes precedence
• CPC Class Codes: G01C 21/30 Map- or contour-matching
• CPC Class Codes: G01C 21/3602 Input other than that of destination using image analysis, e.g. detection of road signs, lanes, buildings, real preceding vehicles using a camera
• CPC Class Codes: G01S 13/86 Combinations of radar systems with non-radar systems, e.g. sonar, direction finder
• CPC Class Codes: G01S 19/485 whereby the further system is an optical system or imaging system

Abstract

A system and method for estimating location and motion of an object. An image of a ground surface is obtained and a first set of features is extracted from the image. A map database is searched for a second set of features that match the first set of features and a geo-location is retrieved from the map database, wherein the geo-location is associated with the second set of features. The location is estimated based on the retrieved geo-location. The motion of the object, such as distance travelled, path travelled and/or speed may be estimated in a similar manner by comparing the location of extracted features that are present in two or more images over a selected time period.

Claims

1. A method for estimating a location comprising:

obtaining an image of a ground surface;

extracting, by a processor, a first set of features from said image;

searching a map database for a second set of features that match said first set of features, wherein said searching is restricted to a subset of said map database, said subset comprising geo-locations within a geographic area of interest;

retrieving a geo-location from said map database, wherein said geo-location is associated with said second set of features; and

estimating, by a processor, said location based on said retrieved geo-location.

2. The method of claim 1, wherein said image is obtained from an electro-optic sensor.

3. The method of claim 1, wherein said ground surfaces include at least one of a road, a parking lot, a field or a trail.

4. A system for estimating a location comprising:

an imaging sensor configured to obtain an image of a ground surface;

a processing module configured to extract a first set of features from said image; and

a map database configured to store a plurality of sets of features and associated geo-locations, wherein said processing module is further configured to search said map database for a second set of features that match said first set of features and retrieve a geo-location associated with said second set of features such that said location is estimated based on said retrieved geo-location, wherein said searching is restricted to a subset of said map database, said subset comprising geo-locations within a geographic area of interest.

5. The system of claim 4, wherein said imaging sensor is an electro-optic sensor.

6. The system of claim 4, further comprising an illumination source configured to strobe in synchronization with said sensor imaging.

7. The system of claim 4, further comprising a GPS receiver, wherein said geographic area of interest is based on an approximate location provided by said GPS receiver.

8. The system of claim 4, wherein said ground surfaces include at least one of a road, a parking lot, a field or a trail.