Terrain map updating system

• US 20090202109A1
• Filed: 02/13/2008
• Published: 08/13/2009
• Est. Priority Date: 02/13/2008
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Lin, Yifeng, Gudat, Adam J., Stratton, Kenneth L., Clar, Jean-Jacques
• Granted Patent: US 8,351,684 B2
• Time in Patent Office: Days
• US Class Current: 382/104
• CPC Class Codes: E02F 9/261 Surveying the work-site to be treated
• CPC Class Codes: G01C 15/00 Surveying instruments or accessories not provided for in groups G01C1/00 - G01C13/00
• CPC Class Codes: G06T 17/05 Geographic models
• CPC Class Codes: G09B 29/003 Maps
• CPC Class Codes: G09B 29/12 Relief maps relief models G09B25/06

Abstract

A terrain mapping system is disclosed. The system has at least one sensor configured to gather a plurality of current points defining a current surface of a site and a database containing a plurality of previously-gathered points defining a previous surface of the site. The system also has a controller in communication with the at least one sensor. The controller is configured to compare a height of at least one of the plurality of the current points to a height of a corresponding at least one of the plurality of previously-gathered points and to determine if an update to the database is warranted based on the comparison. The controller is further configured to update the database if it is determined that an update is warranted.

Claims

1. A terrain mapping system, comprising:

at least one sensor configured to gather a plurality of current points defining a current surface of a site;

a database containing a plurality of previously-gathered points defining a previous surface of the site;

a controller in communication with the at least one sensor, the controller being configured to;

compare a height of at least one of the plurality of the current points to a height of a corresponding at least one of the plurality of previously-gathered points;

determine if an update to the database is warranted based on the comparison; and

update the database if it is determined that an update is warranted.

2. The system of claim 1, wherein:

comparing includes calculating a difference in the height between the at least one of the plurality of current points and the height of the corresponding at least one of the plurality of previously-gathered points to a threshold,

determining if an update to the database is warranted includes determining if a magnitude of the difference in the height is greater than or equal to the threshold, and

the controller is configured to determine that an update to the database is warranted if the magnitude of the difference in the height is greater than or equal to the threshold.

3. The system of claim 1, wherein the controller is further configured to discard the at least one of the plurality of current points when it is determined that an update to the database is not warranted.

4. The system of claim 1, wherein updating the database includes replacing the at least one of the plurality of previously-gathered points with the at least one of the plurality of current points.

5. The system of claim 1, wherein the at least one sensor is positioned at a known location with respect to the site.

6. A terrain mapping method, comprising:

gathering a plurality of current points defining a current surface of a site;

comparing a height of at least one of the current points to a height of a corresponding at least one of a plurality of previously-gathered points defining a previous surface of the site and stored in a database;

determining if an update to the database is warranted based on the comparison; and

updating the database if it is determined that an update is warranted.

7. The method of claim 6, wherein:

comparing includes calculating a difference in the height between the at least one of the plurality of current points and the height of the corresponding at least one of the plurality of previously-gathered points to a threshold,

determining if an update to the database is warranted includes determining if a magnitude of the difference in the height is greater than or equal to the threshold, and

it is determined that an update to the database is warranted if the magnitude of the difference in the height is greater than or equal to the threshold.

8. The method of claim 6, further including discarding the at least one of the plurality of current points when it is determined that an update to the database is not warranted.

9. The method of claim 6, wherein updating the database includes replacing the at least one of the plurality of previously-gathered points with the at least one of the plurality of current points.

10. The method of claim 6, wherein the plurality of current points are gathered by a at least one sensor positioned at a known location with respect to the site.

11. A terrain mapping system, comprising:

at least one sensor configured to gather a plurality of points defining a surface of a site; and

a controller in communication with the at least one sensor, the controller being configured to;

identify points among the gathered plurality of points that do not define terrain of the site;

filter from the gathered plurality of points the identified points that do not define the terrain of the site; and

generate a map of the terrain based on the filtered gathered plurality of points.

12. The system of claim 11, wherein:

the points that do not define terrain of the site include at least one of points that fall outside a site boundary and points defining objects on the surface of the site, and

the controller is further configured to receive at least one characteristic of at least one of the objects, wherein the identifying is based on the at least one characteristic.

13. The system of claim 12, wherein the at least one characteristic includes at least one of a geometry, a color, a location, an orientation, a gradient, and a time location associated with the least one of the objects.

14. The system of claim 12, wherein the controller is in communication with the at least one of the objects and configured to receive therefrom the at least one characteristic.

15. The system of claim 12, wherein the at least one of the objects is a mobile machine on the site.

16. The system of claim 11, wherein identifying includes:

identifying points defining boundaries between the objects and the terrain;

identifying points defining edges of the objects; and

identifying points defining surfaces between the boundaries and the edges.

17. A method of mapping terrain, comprising:

gathering a plurality of points defining a surface of a site;

identifying points among the gathered plurality of points that do not define terrain of the site;

filtering from the gathered plurality of points the identified points that do not define the terrain of the site; and

generating a map of the terrain using the filtered gathered plurality of points.

18. The method of claim 17, wherein the points that do not define terrain of the site include at least one of points that fall outside a site boundary and points defining objects on the surface of the site.

19. The method of claim 18, wherein:

the at least one of the objects is a mobile machine on the site, and

the gathered plurality of points are gathered by at least one sensor is positioned at a known location with respect to the site.

20. The method of claim 18, further including receiving at least one characteristic of at least one of the objects, wherein the identifying is based on the at least one characteristic.

21. The method of claim 19, wherein:

the at least one characteristic includes at least one of a geometry, a color, a location, an orientation, a gradient, and a time location associated with the least one of the objects, and

the at least one characteristic is received from the at least one of the objects.

22. The method of claim 17, wherein identifying includes:

identifying points defining boundaries between the objects and the terrain;

identifying points defining edges of the objects; and

identifying points defining surfaces between the boundaries and the edges.