Two-antenna positioning system for surface-mine equipment

• US 6,191,733 B1
• Filed: 06/01/1999
• Issued: 02/20/2001
• Est. Priority Date: 06/01/1999
• Status: Expired due to Term

• Current Assignee: Modular Mining Systems Incorporated (Komatsu Ltd.)
• Original Assignee: Modular Mining Systems Incorporated (Komatsu Ltd.)
• Inventors: Dizchavez, Ruben Flores
• Primary Examiner(s): Blum, Theodore M.
• Application Number:
  US09/323,190
• Time in Patent Office: 630 Days
• Field of Search: 342/357.17, 701/215, 373/48
• US Class Current: 342/357.57
• CPC Class Codes: G01S 5/0247 Determining attitude

Abstract

Two GPS units are mounted at two separate points on the body of a work machine to periodically measure their three-dimensional coordinates with respect to a chosen reference system. As soon as two sets of measurements are recorded, a plane is fitted through the four points so collected and it is used to determined the current orientation of the machine. As each additional set of position data is collected at predetermined intervals for the two points on the machine, a new plane equation is calculated to update the orientation of the machine based on a predetermined number of prior measurements. Standard-deviation analysis is used to check the validity of each plane calculation and the process is restarted when the deviation is found to be greater than an acceptable parameter. Based on the current coordinates of the two GPS antennae, the current orientation plane so calculated, and the known geometry of the work machine, the current position of its critical components can be determined as well irrespective of the specific motion pattern of the machine.

Claims

1. A method for determining the spatial location and orientation of a work machine having a known geometry, comprising the following steps:

(a) determining spatial coordinates of a first point on the work machine corresponding to a position along a trajectory traveled by said first point in three-dimensional space;

(b) determining spatial coordinates of a second point on the work machine corresponding to a position along a trajectory traveled by said second point in three-dimensional space;

(c) repeating steps (a) and (b) a predetermined number of times to produce a plurality of said coordinates of the first and second points on the work machine corresponding to successive positions along said trajectories traveled in three-dimensional space;

(d) fitting a surface equation through said plurality of coordinates and determining orientation parameters for the surface equation so produced; and

(e) calculating a spatial location and orientation parameters of the work machine utilizing current spatial coordinates for said first and second points on the work machine, the orientation parameters of the surface equation calculated in step (d), and the known geometry of the work machine.

2. The method of claim 1, further including the following step:

(f) successively repeating steps (a), (b), (d) and (e) to determine current coordinates of said first and a second points on the work machine;

to produce a current plurality of said coordinates of the first and second points on the work machine based on a predetermined number of most recent measurements;

to fit a current surface equation through said current plurality of coordinates;

to determine current orientation parameters for the current surface equation so produced in step (d); and

to calculate a current spatial location and current orientation parameters of the work machine utilizing current spatial coordinates for the first and second points on the work machine, the current orientation parameters of the surface equation, and the known geometry of the work machine.

3. The method of claim 1, further including the steps of:

calculating a standard deviation for said plurality of coordinates used in step (d);

comparing the standard deviation to a predetermined parameter;

if the standard deviation is smaller than said predetermined parameter, continuing to step (e);

if the standard deviation is equal to or greater than said predetermined parameter, repeating steps (a) and (b) at least once to produce a new plurality of said coordinates of the first and second points on the work machine corresponding to successive positions along said trajectories traveled in three-dimensional space; and

continuing with step (d) using said new plurality of coordinates.

4. The method of claim 2, further including the steps of:

calculating a standard deviation for said plurality of coordinates used in step (d);

comparing the standard deviation to a predetermined parameter;

if the standard deviation is smaller than said predetermined parameter, continuing to step (e);

if the standard deviation is equal to or greater than said predetermined parameter, repeating steps (a) and (b) at least once to produce a new plurality of said coordinates of the first and second points on the work machine corresponding to successive positions along said trajectories traveled in three-dimensional space; and

continuing with step (d) using said new plurality of coordinates.

5. The method of claim 1, wherein at least one of said steps (a) and (b) is carried out using a global-positioning-system unit.

6. The method of claim 1, wherein said surface equation in step (d) is a plane equation.

7. The method of claim 6, wherein said step (d) is carried out using linear regression.

8. The method of claim 1, wherein said predetermined number of times in step (c) is at least two.

9. The method of claim 2, wherein said predetermined number of most recent measurements is twenty.

10. The method of claim 1, wherein said predetermined parameter is 30 cm.

11. A method for determining the spatial location and orientation of a work machine having a known geometry, comprising the following steps:

(a) determining spatial coordinates of a first point on the work machine corresponding to a position along a trajectory traveled by said first point in three-dimensional space;

(b) determining spatial coordinates of a second point on the work machine corresponding to a position along a trajectory traveled by said second point in three-dimensional space;

(c) repeating steps (a) and (b) a predetermined number of times to produce a plurality of said coordinates of the first and second points on the work machine corresponding to successive positions along said trajectories traveled in three-dimensional space;

(d) fitting a surface equation through said plurality of coordinates and determining orientation parameters for the surface equation so produced; and

(e) calculating a spatial location and orientation parameters of the work machine utilizing current spatial coordinates for said first and second points on the work machine, the orientation parameters of the surface equation calculated in step (d), and the known geometry of the work machine;

wherein said step (d) is carried out using linear regression.

12. The method of claim 11, further including the following step:

(f) successively repeating steps (a), (b), (d) and (e) to determine current coordinates of said first and a second points on the work machine;

to produce a current plurality of said coordinates of the first and second points on the work machine based on a predetermined number of most recent measurements;

to fit a current surface equation through said current plurality of coordinates;

to determine current orientation parameters for the current surface equation so produced in step (d); and

to calculate a current spatial location and current orientation parameters of the work machine utilizing current spatial coordinates for the first and second points on the work machine, the current orientation parameters of the surface equation, and the known geometry of the work machine.

13. The method of claim 11, further including the steps of:

calculating a standard deviation for said plurality of coordinates used in step (d);

comparing the standard deviation to a predetermined parameter;

if the standard deviation is smaller than said predetermined parameter, continuing to step (e);

if the standard deviation is equal to or greater than said predetermined parameter, repeating steps (a) and (b) at least once to produce a new plurality of said coordinates of the first and second points on the work machine corresponding to successive positions along said trajectories traveled in three-dimensional space; and

continuing with step (d) using said new plurality of coordinates.

14. The method of claim 12, further including the steps of:

calculating a standard deviation for said plurality of coordinates used in step (d);

comparing the standard deviation to a predetermined parameter;

if the standard deviation is smaller than said predetermined parameter, continuing to step (e);

if the standard deviation is equal to or greater than said predetermined parameter, repeating steps (a) and (b) at least once to produce a new plurality of said coordinates of the first and second points on the work machine corresponding to successive positions along said trajectories traveled in three-dimensional space; and

continuing with step (d) using said new plurality of coordinates.

15. The method of claim 11, wherein at least one of said steps (a) and (b) is carried out using a global-positioning-system unit.

16. The method of claim 11, wherein said surface equation in step (d) is a plane equation.

17. The method of claim 11, wherein said predetermined number of times in step (c) is at least two.

18. The method of claim 12, wherein said predetermined number of most recent measurements is twenty.

19. The method of claim 11, wherein said predetermined parameter is 30 cm.

20. A method for determining the spatial location and orientation of a work machine having a known geometry, comprising:

(a) determining a plurality of coordinates of a first point on the work machine corresponding to successive positions along a trajectory traveled by said first point in three-dimensional space;

(b) determining a plurality of coordinates of a second point on the work machine corresponding to successive positions along a trajectory traveled by said second point in three-dimensional space;

(c) fitting a surface equation through said plurality of coordinates determined in steps (a) and (b); and

(d) calculating a spatial location and orientation parameters of the work machine on the basis of current coordinates of said first and second points on the work machine, orientation parameters of said surface equation, and said known geometry of the work machine.

21. The method of claim 20, wherein at least one of said steps (a) and (b) is carried out using a global-positioning-system unit.

22. The method of claim 20, wherein said surface equation in step (c) is a plane equation.

23. A method for determining the spatial location and orientation of a work machine having a known geometry, comprising:

(a) determining a plurality of coordinates of a first point on the work machine corresponding to successive positions along a trajectory traveled by said first point in three-dimensional space;

(b) determining a plurality of coordinates of a second point on the work machine corresponding to successive positions along a trajectory traveled by said second point in three-dimensional space;

(c) fitting a surface equation through said plurality of coordinates determined in steps (a) and (b); and

(d) calculating a spatial location and orientation parameters of the work machine on the basis of current coordinates of said first and second points on the work machine, orientation parameters of said surface equation, and said known geometry of the work machine;

wherein said step (c) is carried out using linear regression.

24. The method of claim 23, wherein at least one of said steps (a) and (b) is carried out using a global-positioning-system unit.

25. The method of claim 23, wherein said surface equation in step (c) is a plane equation.

26. An apparatus for determining the spatial location and orientation of a work machine having a known geometry, comprising:

first means for determining position coordinates of a first point on the work machine in three-dimensional space at successive times corresponding to successive positions along a travel trajectory of said first point;

second means for determining position coordinates of a second point on the work machine in three-dimensional space at successive times corresponding to successive positions along a travel trajectory of said second point;

means for storing a plurality of said position coordinates of the first and second points on the work machine;

means for fitting a surface equation through said plurality of position coordinates of the first and second points on the work machine and for determining orientation parameters for said surface equation; and

means for calculating a spatial location and orientation of the work machine utilizing a current set of position coordinates for said first and second points on the work machine, the orientation parameters corresponding to a current surface equation, and the known geometry of the work machine.

27. The apparatus of claim 26, wherein at least one of said first and second means for determining position coordinates includes a global-positioning-system unit.

28. The apparatus of claim 26, wherein said surface equation is a plane equation.

29. An apparatus for determining the spatial location and orientation of a work machine having a known geometry, comprising:

first means for determining position coordinates of a first point on the work machine in three-dimensional space at successive times corresponding to successive positions along a travel trajectory of said first point;

second means for determining position coordinates of a second point on the work machine in three-dimensional space at successive times corresponding to susccessive positions along a travel trajectory of said second point;

means for storing a plurality of said position coordinates of the first and second points on the work machine;

means for fitting a surface equation through said plurality of position coordinates of the first and second points on the work machine and for determining orientation parameters for said surface equation; and

means for calculating a spatial location and orientation of the work machine utilizing a current set of position coordinates for said first and second points on the work machine, the orientation parameters corresponding to a current surface equation, and the known geometry of the work machine;

wherein said means for fitting a surface equation includes means for implementing linear regression on said plurality of position coordinates.

30. The apparatus of claim 29, wherein said surface equation is a plane equation.

31. The apparatus of claim 29, wherein at least one of said first and second means for determining position coordinates includes a global-positioning-system unit.

32. The apparatus of claim 29, wherein said surface equation is a plane equation.