Virtual field-based track protection for a mining machine

1. A method for preventing and mitigating collisions between a dipper and tracks of a mining machine, the method comprising:

receiving dipper position data indicative of a position of the dipper;

setting, based on the dipper position data, a motion command limit for a dipper motion, the dipper motion being selected from a group of a swing motion, a crowd motion, and a hoist motion;

comparing a dipper motion command input to the motion command limit;

controlling the dipper motion according to a first dipper motion command when the dipper motion command input is less than the motion command limit; and

generating a second dipper motion command and controlling the dipper motion according to the second dipper motion command when the dipper motion command input exceeds the motion command limit.

2. The method of claim 1 , wherein, to set the motion command limit for the dipper motion based on the dipper position data, the method further comprises at least one selected from the group of:

(i) calculating a distance between the dipper and the tracks of the mining machine and using the distance as an input to a distance-based function that defines the motion command limit based on the distance, and

(ii) using the dipper position data as an input to a position-based function that defines the motion command limit based on the dipper position data, where the position-based function is defined based on relationships between potential dipper positions and associated distances between the potential dipper positions and the tracks of the mining machine.

3. The method of claim 1 , further comprising:

determining a position of a three-dimensional virtual dipper model in a three-dimensional coordinate system for the mining machine based on the dipper position data;

determining a position of a three-dimensional virtual tracks model in the three-dimensional coordinate system; and

determining, by the electronic processor, a shortest distance between the three- dimensional virtual dipper model and the three-dimensional virtual tracks model, wherein the shortest distance represents the distance between the dipper and the tracks.

4. The method of claim 3 , wherein the distance is a three-dimensional distance indicating a length across three dimensions of space.

5. The method of claim 1 , wherein setting the motion command limit for the dipper motion based on the dipper position data comprises:

reducing the motion command limit from an initial value to a reduced value according to a function that defines the motion command limit to be lower as a distance between the dipper and the tracks of the mining machine is reduced.

6. The method of claim 5 , further comprising:

receiving updated dipper position data indicative of an updated position of the dipper;

determining an updated distance between the dipper and the tracks of the mining machine based on the updated dipper position data, where the updated distance is greater than the distance;

setting the motion command limit to an updated value based on the updated distance, where the updated value is greater than the reduced value; and

controlling the dipper motion according to a further dipper motion command limited by the motion command limit having the updated value.

7. The method of claim 5 , wherein the function defines a virtual three- dimensional field around the dipper for the dipper motion.

8. The method of claim 1 , wherein setting the motion command limit for the dipper motion based on the dipper position data comprises:

when a distance between the dipper and the tracks of the mining machine is below a stop region threshold, setting the motion command limit according to a stop region function, and

when the distance is above the stop region threshold and below a slow region threshold, setting the motion command limit according to a slow region function.

9. The method of claim 1 , wherein the dipper motion is the crowd motion and motion command limit is a crowd motion command limit, the method further comprising:

setting a hoist motion command limit for the hoist motion based on a distance between the dipper and the tracks of the mining machine.

10. The method of claim 9 , further comprising:

setting a swing motion command limit for the swing motion based on a distance between the dipper and the tracks of the mining machine.

11. The method of claim 1 , further comprising:

repeatedly receiving the dipper position data indicative of the position of the dipper over time as the dipper moves; and

updating the motion command limit based on the dipper position data as the dipper position data is repeatedly received.

12. The method of claim 1 , further comprising:

determining a shortest distance between a three-dimensional virtual dipper model and a three-dimensional virtual tracks model, wherein the shortest distance represents the distance between the dipper and the tracks;

and wherein the three-dimensional virtual tracks model is generated by:

moving the dipper to a first position associated with the tracks,

determining a first data point associated with the first position,

moving the dipper to a second position associated with the tracks,

determining a second data point associated with the second position, and

generating a virtual model of the tracks by extrapolating virtual boundaries of the tracks from the first data point and the second data point.

13. A mining machine with a collision prevention and mitigation system, the mining machine comprising:

a frame;

tracks supporting the frame and configured to be driven to move the frame over a ground surface;

a dipper supported by the frame;

a dipper drive coupled to the dipper and configured to move the dipper in a dipper motion selected from a group of a swing motion, a crowd motion, and a hoist motion;

a dipper position sensor configured to determine a position of the dipper;

an electronic controller including an electronic processor and a memory, the electronic controller coupled to the dipper drive and the dipper position sensor, the electronic controller configured to:

receive dipper position data from the dipper position sensor indicative of a position of the dipper,

set a motion command limit for the dipper motion based on the dipper position data,

compare a dipper motion command input to the motion command limit,

control, via the dipper drive, the dipper motion according to a first dipper motion command when the dipper motion command input is less than the motion command limit; and

generate a second dipper motion command and control the dipper motion according to the second dipper motion command when the dipper motion command input exceeds the motion command limit.

14. The mining machine of claim 13 , wherein, to set the motion command limit for the dipper motion based on the dipper position data, the electronic controller is configured to at least one selected from the group of:

(i) calculate a distance between the dipper and the tracks of the mining machine and using the distance as an input to a distance-based function that defines the motion command limit based on the distance, and

(ii) use the dipper position data as an input to a position-based function that defines the motion command limit based on the dipper position data, where the position-based function is defined based on relationships between potential dipper positions and associated distances between the potential dipper positions and the tracks of the mining machine.

15. The mining machine of claim 13 , wherein the electronic controller is further configured to:

determine a position of a three-dimensional virtual dipper model in a three-dimensional coordinate system for the mining machine based on the dipper position data;

determine a position of a three-dimensional virtual tracks model in the three-dimensional coordinate system; and

determine a shortest distance between the three-dimensional virtual dipper model and the three-dimensional virtual tracks model, wherein the shortest distance represents the distance between the dipper and the tracks.

16. The mining machine of claim 15 , wherein, to set the motion command limit for the dipper motion based on the dipper position data, the electronic controller is configured to:

reduce the motion command limit from an initial value to a reduced value according to a function that defines the motion command limit to be lower as a distance between the dipper and the tracks of the mining machine is reduced.

17. The mining machine of claim 16 , wherein the electronic controller is further configured to:

receive updated dipper position data indicative of an updated position of the dipper;

determine an updated distance between the dipper and the tracks of the mining machine based on the updated dipper position data, where the updated distance is greater than the distance;

set the motion command limit to an updated value based on the updated distance, where the updated value is greater than the reduced value; and

control the dipper motion according to a further dipper motion command limited by the motion command limit having the updated value.

18. The mining machine of claim 16 , wherein the function defines a virtual three-dimensional field around the dipper for the dipper motion.

19. The mining machine of claim 13 , wherein, to set the motion command limit for the dipper motion based on the dipper position data, the electronic controller is configured to:

set the motion command limit according to a stop region function when a distance between the dipper and the tracks of the mining machine is below a stop region threshold, and

set the motion command limit according to a slow region function when the distance is above the stop region threshold and below a slow region threshold.

20. The mining machine of claim 13 , wherein the dipper motion is the crowd motion and motion command limit is a crowd motion command limit, and wherein the electronic controller is further configured to:

set a hoist motion command limit for the hoist motion based on a distance between the dipper and the tracks of the mining machine.

21. The mining machine of claim 20 , wherein the electronic controller is further configured to:

set a swing motion command limit for the swing motion based on a distance between the dipper and the tracks of the mining machine.

22. The mining machine of claim 13 , wherein the electronic controller is further configured to:

repeatedly receive the dipper position data indicative of the position of the dipper over time as the dipper moves; and

update the motion command limit based on the dipper position data as the dipper position data is repeatedly received.

23. A collision prevention and mitigation control system for a mining machine having a frame, tracks supporting the frame and configured to be driven to move the frame over a ground surface, a dipper supported by the frame, a dipper drive coupled to the dipper and configured to move the dipper in a dipper motion selected from a group of a swing motion, a crowd motion, and a hoist motion, a dipper position sensor configured to determine a position of the dipper, the control system comprising:

an electronic controller including an electronic processor and a memory, the electronic controller coupled to the dipper drive and the dipper position sensor, the electronic controller configured to:

receive dipper position data from the dipper position sensor indicative of a position of the dipper,

set a motion command limit for the dipper motion based on the dipper position data,

compare a dipper motion command input to the motion command limit,

control, via the dipper drive, the dipper motion according to a first dipper motion command when the dipper motion command input is less than the motion command limit, and

generating a second dipper motion command and controlling the dipper motion according to the second dipper motion command when the dipper motion command input exceeds the motion command limit.

24. The control system of claim 23 , wherein, to set the motion command limit for the dipper motion based on the dipper position data, the electronic controller is configured to at least one selected from the group of:

(i) calculate a distance between the dipper and the tracks of the mining machine and using the distance as an input to a distance-based function that defines the motion command limit based on the distance, and

(ii) use the dipper position data as an input to a position-based function that defines the motion command limit based on the dipper position data, where the position-based function is defined based on relationships between potential dipper positions and associated distances between the potential dipper positions and the tracks of the mining machine.

25. The control system of claim 23 , wherein the electronic controller is further configured to:

determine a position of a three-dimensional virtual dipper model in a three-dimensional coordinate system for the mining machine based on the dipper position data;

determine a position of a three-dimensional virtual tracks model in the three-dimensional coordinate system; and

determine a shortest distance between the three-dimensional virtual dipper model and the three-dimensional virtual tracks model, wherein the shortest distance represents the distance between the dipper and the tracks.

26. The control system of claim 25 , wherein, to set the motion command limit for the dipper motion based on the dipper position data, the electronic controller is configured to:

reduce the motion command limit from an initial value to a reduced value according to a function that defines the motion command limit to be lower as a distance between the dipper and the tracks of the mining machine is reduced.

27. The control system of claim 26 , wherein the electronic controller is further configured to:

receive updated dipper position data indicative of an updated position of the dipper;

determine an updated distance between the dipper and the tracks of the mining machine based on the updated dipper position data, where the updated distance is greater than the distance;

set the motion command limit to an updated value based on the updated distance, where the updated value is greater than the reduced value; and

control the dipper motion according to a further dipper motion command limited by the motion command limit having the updated value.

28. The control system of claim 26 , wherein the function defines a virtual three-dimensional field around the dipper for the dipper motion.

29. The control system of claim 23 , wherein, to set the motion command limit for the dipper motion based on the dipper position data, the electronic controller is configured to:

set the motion command limit according to a stop region function when a distance between the dipper and the tracks of the mining machine is below a stop region threshold, and

set the motion command limit according to a slow region function when the distance is above the stop region threshold and below a slow region threshold.

30. The control system of claim 23 , wherein the dipper motion is the crowd motion and motion command limit is a crowd motion command limit, and wherein the electronic controller is further configured to:

set a hoist motion command limit for the hoist motion based on a distance between the dipper and the tracks of the mining machine.

31. The control system of claim 30 , wherein the electronic controller is further configured to:

set a swing motion command limit for the swing motion based on a distance between the dipper and the tracks of the mining machine.

32. The control system of claim 23 , wherein the electronic controller is further configured to:

repeatedly receive the dipper position data indicative of the position of the dipper over time as the dipper moves; and

update the motion command limit based on the dipper position data as the dipper position data is repeatedly received.