Positioning system

• US 10,203,412 B2
• Filed: 09/20/2013
• Issued: 02/12/2019
• Est. Priority Date: 09/20/2013
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Smith, David William, Broughton, Peter John
• Primary Examiner(s): Hellner, Mark
• Application Number:
  US15/021,760
• Publication Number:
  US 20160223673A1
• Time in Patent Office: 1,971 Days
• Field of Search: 356 401
• CPC Class Codes: G01S 17/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S17/46
• CPC Class Codes: G01S 17/89 for mapping or imaging

Abstract

A method for determining a position of a machine is disclosed. The method may include determining, using a Lidar unit on the machine, input data associated with distances between the Lidar unit and respective light-reflective points in the worksite. The method may also include comparing the input data with comparison data. The comparison data may have reference data sets indicative of distances between reference positions and the respective light-reflective points in the worksite. The reference positions may have a fixed location in the worksite. The method may further include determining the position of the machine as the reference position corresponding to a reference data set that correlates with the input data set.

Claims

1. A method for determining a position of a machine in a worksite, the method comprising:

determining, using a Lidar unit on the machine, input data associated with distances between the Lidar unit and respective light-reflective points in the worksite;

comparing the input data with first comparison data including at least one reference data set indicative of distances between at least one reference position and the respective light-reflective points in the worksite, the at least one reference position having a fixed location in the worksite; and

determining a first position of the machine based on the first comparison data when the input data and the at least one reference data set satisfy a predefined condition, wherein comparing the input data and the at least one reference data set includes;

determining a correlation between the input data and the at least one reference data set; and

comparing the correlation with a threshold, and wherein the predefined condition includes the correlation is less than the threshold.

2. The method according to claim 1, wherein the at least one reference data set has an associated identifier, and the method further includes determining the threshold based on the associated identifier.

3. The method according to claim 1, wherein the input data is first input data, and the method further includes:

determining, using the Lidar unit, second input data associated with the distances between the Lidar unit and the respective light-reflective points in the worksite when the machine is located at a second position different from the first position;

determining second comparison data based on the first position; and

comparing the second input data with second comparison data to determine the second position.

4. The method according to claim 3, wherein determining the second comparison data includes:

identifying reference positions having spacings from the first position that are less than a threshold spacing; and

including reference data sets corresponding to the reference positions in the second comparison data.

5. The method according to claim 4, wherein the correlation is a first correlation, the threshold is a first threshold, and comparing the second input data with the second comparison data includes:

determining a second correlation between the second input data and at least one second reference data set selected from the second comparison data, and comparing the second correlation with a second threshold.

6. The method according to claim 5, wherein the second threshold is different from the first threshold.

7. The method according to claim 1, wherein the at least one reference data set is a first reference data set corresponding to a first reference position and the first comparison data includes a second reference data set corresponding to a second reference position, comparing the input data with the first comparison data includes:

determining a first correlation between the input data and the first reference data set;

determining a second correlation between the input data and the second reference data set;

determining a first difference between the first correlation and a threshold, and

determining a second difference between the second correlation and the threshold, and

determining that the first position is the first reference position when the first difference is smaller than the second difference.

8. The method according to claim 1, wherein the first comparison data includes a plurality of reference data sets corresponding to a plurality of reference positions, the reference positions being separated from each other in the worksite.

9. The method according to claim 1, wherein the method includes determining the first comparison data during an installation of a positioning system in the worksite.

10. The method according to claim 1, wherein the at least one reference position is one of an ore pass, a distinctive marker added to the worksite, a unique cutaway, an air vent, a road intersection, and a storage area cut into a sidewall of a tunnel in the worksite.

11. The method according to claim 1, wherein the input data is first input data, the position of the machine is an initial position, and when the first input data and the at least one reference data set do not satisfy the predefined condition, the method further includes:

determining, using the Lidar unit on the machine, second input data associated with the distances between the Lidar unit and respective light-reflective points in the worksite from a new position of the machine different from the initial position;

comparing the second input data with the first comparison data; and

determining the first position of the machine based on the first comparison data when the second input data and the at least one reference data set satisfy the predefined condition.

12. A system for determining a position of a machine in a worksite, the system comprising:

a Lidar unit attached to the machine;

a controller in communication with the Lidar unit, the controller being configured to;

receive, from the Lidar unit, input data associated with distances between the Lidar unit and respective light-reflective points in the worksite;

compare the input data with first comparison data including at least one reference data set indicative of distances between at least one reference position and the respective light-reflective points in the worksite, the at least one reference position having a fixed location in the worksite; and

determine a first position of the machine based on the first comparison data when the input data and the at least one reference data set satisfy a predefined condition, wherein the at least one reference data set is a first reference data set corresponding to a first reference position and the first comparison data includes a second reference data set corresponding to a second reference position, and the controller is further configured to;

compare the input data with the first comparison data by;

determining a first correlation between the input data and the first reference data set;

determining a second correlation between the input data and the second reference data set;

determining a first difference between the first correlation and a threshold, and

determining a second difference between the second correlation and the threshold, and

determine that the first position is the first reference position when the first difference is smaller than the second difference.

13. The system according to claim 12, wherein the controller is further configured to:

compare the input data and the at least one reference data set by;

determining a correlation between the input data and the at least one reference data set; and

comparing the correlation with a threshold, and

determine that the input data and the at least one reference data set satisfy the predefined condition when the correlation is less than the threshold.

14. The system according to claim 13, wherein the at least one reference data set has an associated identifier, and the method further includes determining the threshold based on the associated identifier.

15. The system according to claim 12, wherein the at least one landmark is one of an ore pass, a distinctive marker added to the worksite, a unique cutaway, an air vent, a road intersection, and a storage area cut into a sidewall of a tunnel in the worksite.

16. The system according to claim 12, wherein the input data is first input data, the position of the machine is an initial position, and the controller is further configured to:

receive, from the Lidar unit, second input data associated with the distances between the Lidar unit and the respective light-reflective points in the worksite when the machine is located at a second position different from the first position;

determine second comparison data based on the first position; and

compare the second input data with second comparison data to determine the second position.

17. The system according to claim 16, wherein the controller is configured to determine the second comparison data by:

identifying reference positions having spacings from the position that are less than a threshold spacing; and

including reference data sets corresponding to the reference positions in the second comparison data.