Method and apparatus for detecting obstacles using multiple sensors for range selective detection

• US 6,055,042 A
• Filed: 12/16/1997
• Issued: 04/25/2000
• Est. Priority Date: 12/16/1997
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Sarangapani, Jagannathan
• Primary Examiner(s): Buczinski, Stephen C.
• Application Number:
  US08/991,495
• Time in Patent Office: 861 Days
• Field of Search: 901/46, 901/47, 180/167-169, 356/4.01, 356/5.01, 172/5, 342/71, 367/96
• US Class Current: 356/4.01
• CPC Class Codes: G01S 13/87 Combinations of radar systems, e.g. primary radar and secondary radar
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 15/931 of land vehicles
• CPC Class Codes: G01S 17/931 of land vehicles
• CPC Class Codes: G01S 2013/93271 in the front of the vehicles
• CPC Class Codes: G01S 2013/93273 on the top of the vehicles

Abstract

A method and apparatus is disclosed to detect an obstacle in the path of a mobile machine. The present invention scans a field of interest by each of a plurality of obstacle sensor systems, weights the scanned data received from the obstacle sensor systems, and determines at least one characteristic of the obstacle as a function of the weighted scanned data.

Claims

1. A method for detecting an obstacle in the path of a mobile machine, including the steps of:

scanning a field of interest by each of a plurality of obstacle sensor systems;

determining a zone of interest from each field of interest as a function of a terrain map database located on the mobile machine;

weighting the scanned data received from the obstacle sensor systems as a function of at least one parameter; and

determining at least one characteristic of the obstacle as a function of the weighted scanned data.

2. A method, as set forth in claim 1, wherein an object detected outside the zone of interest is determined to be outside the path of the mobile machine.

3. A method, as set forth in claim 1, including the step of determining the range to the obstacle as being one of a near range and a far range.

4. A method, as set forth in claim 3, wherein the scanned data from a first set of obstacle sensor systems is weighted in response to determining the range to the obstacle as being a near range.

5. A method, as set forth in claim 3, wherein the scanned data from a second set of obstacle sensor systems is weighted in response to determining the range to the obstacle as being a far range.

6. A method, as set forth in claim 1, wherein each of the plurality of obstacle sensor systems is configured to scan a predetermined portion of the field of interest.

7. A method, as set forth in claim 1, wherein each of the plurality of obstacle sensor systems is configured to scan the field of interest with a sensor having characteristics unique to each other of the plurality of obstacle sensor systems.

8. A method, as set forth in claim 1, wherein each of the plurality of obstacle sensor systems is configured to scan at least one of a predetermined portion of the field of interest and the field of interest with a sensor having characteristics unique to each other of the plurality of obstacle sensor systems.

9. A method, as set forth in claim 1, wherein the at least one parameter includes an amount of ambient light available.

10. A method, as set forth in claim 1, wherein the at least one parameter includes a size of the obstacle.

11. A method, as set forth in claim 1, wherein the at least one parameter includes an amount of reflected power received by at least one of the plurality of obstacle sensor systems, the reflected power being a function of a shape and a composition of the obstacle.

12. A method, as set forth in claim 1, wherein weighting the scanned data is performed using empirically obtained values of weights.

13. A method, as set forth in claim 1, wherein determining at least one characteristic of the obstacle includes the step of calculating an average of the weighted scanned data.

14. A method, as set forth in claim 1, wherein determining at least one characteristic of the obstacle includes the steps of:

weighting the scanned data received from each of the obstacle sensor systems as a function of a respective at least one parameter;

summing the weighted scanned data; and

dividing the summed scanned data by the sum of a plurality of weight values used to weight the scanned data.

15. A method, as set forth in claim 1, wherein the at least one characteristic of the obstacle is a probability of existence of the obstacle.

16. A method, as set forth in claim 1, wherein the at least one characteristic of the obstacle is a location of the obstacle.

17. A method, as set forth in claim 1, wherein the at least one characteristic of the obstacle is an orientation of the obstacle.

18. A method, as set forth in claim 1, wherein the at least one characteristic of the obstacle is a size of the obstacle.

19. An apparatus for detecting an obstacle in the path of a mobile machine, comprising:

an obstacle detection system located on the mobile machine, the obstacle detection system including a plurality of obstacle sensor systems;

a terrain map database located on the mobile machine;

means located on the mobile machine for determining at least one parameter; and

a control system located on the mobile machine for receiving a signal having scanned data from each of the plurality of obstacle sensor systems, weighting the scanned data from each obstacle sensor system as a function of the at least one parameter, and determining at least one characteristic of the obstacle as a function of the weighted scanned data, the control system being further adapted for determining a zone of interest as a function of the terrain map database, the zone of interest being determined from the field of interest.

20. An apparatus, as set forth in claim 19, wherein each of the plurality of obstacle sensor systems is configured to scan a predetermined portion of a field of interest, and wherein an object detected outside the zone of interest is determined to be outside the path of the mobile machine.

21. An apparatus, as set forth in claim 19, wherein the at least one characteristic of the obstacle is a probability of existence of the obstacle.

22. An apparatus, as set forth in claim 19, wherein the at least one characteristic of the obstacle is a location of the obstacle.

23. An apparatus, as set forth in claim 19, wherein the at least one characteristic of the obstacle is an orientation of the obstacle.

24. An apparatus, as set forth in claim 19, wherein the at least one characteristic of the obstacle is a size of the obstacle.