Apparatus and method for controlling an underground boring machine

• US 20020112893A1
• Filed: 04/22/2002
• Published: 08/22/2002
• Est. Priority Date: 03/13/1996
• Status: Active Grant

• Current Assignee: Vermeer Manufacturing Company
• Original Assignee: Vermeer Manufacturing Company
• Inventors: Bischel, Brian John, Rankin, James Richard
• Granted Patent: US 6,554,082 B2
• Time in Patent Office: Days
• US Class Current: 175/61
• CPC Class Codes: E21B 44/06 in response to the flow or pressure of the motive fluid of the drive

Abstract

An apparatus and method for controlling an underground boring machine during boring or reaming operations. A boring tool is displaced along an underground path while being rotated. In response to variations in underground conditions impacting boring tool progress along the underground path, a control system modifies the rate of boring tool displacement along the underground path while rotating the boring tool at a selected rotation rate to optimize excavation productivity. The controller may also monitor the rate at which liquid is pumped through the borehole and automatically adjust the rate of displacement and/or the liquid flow rate so that sufficient liquid is flowing through the borehole to remove the cuttings and debris generated by the boring tool.

Claims

1. A method for controlling an underground boring tool, comprising the steps of:

displacing the boring tool along an underground path;

rotating the boring tool at a selected rate while displacing the boring tool; and

concurrently modifying the rate of boring tool displacement along the underground path and rotating the boring tool at the selected rotation rate in response to variations in underground conditions impacting boring tool progress along the underground path.

2. The method of claim 1, further comprising the step of producing a rotation pump limit signal in response to a rotation pump pressure exceeding a pre-established rotation pump pressure limit.

3. The method of claim 1, including the further step of increasing the rate of boring tool displacement along the underground path while rotating the boring tool at the selected rate after the rotation pump pressure is reduced to below the rotation pump pressure limit.

4. The method of claim 2, wherein:

rotation and displacement pumps are coupled to an engine for respectively powering the rotation and displacement pumps; and

the modifying step includes the further steps of concurrently operating the engine at a selected engine output level, reducing the rate of boring tool displacement, and rotating the boring tool at the selected rate in response to the rotation pump limit signal.

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

producing a displacement limit signal in response to the boring tool being displaced along the underground path at a rate in excess of a selected displacement rate; and

concurrently reducing the rate of boring tool displacement along the underground path and rotating the boring tool at the selected output level until the rate of boring tool displacement falls below the selected displacement rate in response to displacement limit signal.

6. The method of claim 1, wherein the modifying step further comprises reducing the rate of the boring tool displacement along the underground path after the rotation pressure exceeds a pre-established rotation pump pressure limit between approximately 1000 psi and approximately 6000 psi.

7. The method of claim 1, wherein the modifying step further comprises increasing the rate of boring tool displacement along the underground path within approximately 0.1 seconds and 0.5 seconds of the rotation pressure falling below a pre-established rotation pump set point.

8. The method of claim 1, wherein the modifying step further comprises varying the rate of increase in boring tool displacement along the underground path.

9. The method of claim 8, wherein the varying step includes the step of varying the rate of increase in boring tool displacement while a rotation pump pressure ranges between approximately 100 psi and approximately 1,000 psi in excess of a pre-established rotation pump pressure limit.

10. The method of claim 1, wherein the modifying step includes the step of varying a rate of increase in boring tool displacement within a pre-established period of time ranging between approximately 0.1 seconds and 0.5 seconds after a rotation pump pressure exceeds a pre-established rotation pump pressure limit.

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

flowing a liquid from a liquid dispensing pump to the boring tool;

producing a liquid dispensing pump limit signal in response to the liquid dispensing pump pressure rising above a liquid dispensing pump pressure limit; and

reducing the rate of boring tool displacement along the underground path in response to the liquid dispensing pump limit signal until the liquid dispensing pressure is reduced to a pressure below the liquid dispensing pump pressure limit.

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

flowing a liquid from a liquid dispensing pump to the boring tool at a flow rate; and

modifying the liquid flow rate in response to the boring tool displacement rate.

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

flowing a liquid from a liquid dispensing pump to the boring tool at a flow rate; and

modifying the boring tool displacement rate in response to the liquid flow rate.

14. The method of claim 1, wherein:

rotation and displacement pumps are coupled to an engine for respectively powering the rotation and displacement pumps; and

the modifying step includes the further steps of concurrently monitoring engine performance and altering the rate of boring tool displacement in response to the engine performance.

15. The method of claim 14, wherein the altering step further includes the steps of:

establishing a range of acceptable engine performance; and

reducing the rate of boring tool displacement in response to the engine performance exceeding the range of acceptable engine performance.

17. The system of claim 16, further comprising a rotation control, coupled to the control means, for manually selecting the selected level of the rotation pump, the rotation control having a neutral setting corresponding to non-rotation of the boring tool and a range of rotation settings associated with a corresponding range of rotation pump pressures.

18. The system of claim 16, further comprising a displacement control, coupled to the control means, for manually selecting the displacement rate, the displacement control having a neutral setting corresponding to non-displacement of the boring tool and a range of displacement settings associated with a corresponding range of displacement pump pressures.

19. The system of claim 16, further comprising a liquid dispensing pump, coupled to the control means, for dispensing liquid from the boring tool.

20. The system of claim 16, further comprising a display for displaying information indicative of one of a rotation pump pressure and a rotation rate of the boring tool.

21. The system of claim 16, wherein the control means includes means for concurrently modifying the rate of boring tool displacement along the underground path and operating the rotation pump at the selected level within a period of time ranging between approximately 0.1 seconds and approximately 0.5 seconds following a reduction in rotation pump pressure below a rotation pump pressure set point.

22. The system of claim 16, wherein the control means includes means for varying the rate of boring tool displacement along the underground path while concurrently operating the rotation pump at the selected output level.

23. The system of claim 16, wherein the control means includes means for varying the rate of boring tool displacement along the underground path while concurrently operating the rotation pump within a range of rotation pump pressures between approximately 100 psi and approximately 1,000 psi in excess of the pressure limit.

26. The method of claim 25, wherein monitoring the displacement load further comprises monitoring a rate of change in the displacement load, and automatically modifying the rate of cutting tool displacement further comprises modifying a rate of change in cutting tool displacement as a function of the rate of change in the displacement load.

27. The method of claim 25, wherein the set rate of cutting tool displacement represents a maximum displacement rate, and automatically modifying the rate of cutting tool displacement further comprises modifying the rate of cutting tool displacement so as to avoid exceeding the maximum displacement rate.

28. The method of claim 27, wherein the predetermined displacement load profile comprises a maximum displacement load.

29. The method of claim 27, wherein the predetermined displacement load profile comprises a minimum displacement load and a maximum displacement load.

30. The method of claim 25, wherein automatic modification of the cutting tool displacement rate is accomplished within about 0.1 seconds to about 0.5 seconds.

31. The method of claim 25, further comprising:

setting a liquid flow rate;

calculating a maximum cutting tool displacement rate using the set liquid flow rate; and

automatically adjusting the cutting tool displacement rate in response to the calculated maximum cutting tool displacement rate.

32. The method of claim 31, wherein calculating the maximum cutting tool displacement rate comprises calculating the maximum cutting tool displacement rate based on a size of a borehole produced by the cutting tool, a size of the cutting tool, and the cutting tool displacement rate.

33. The method of claim 25, further comprising:

calculating liquid flow requirements for a borehole produced by the cutting tool;

monitoring an actual rate of liquid flow into the borehole; and

automatically adjusting the actual liquid flow rate such that the actual liquid flow rate equals or exceeds the calculated liquid flow requirements.

35. The system of claim 34, wherein the controller monitors a rate of change in the displacement load and modifies a rate of change in cutting tool displacement as a function of the rate of change in the displacement load.

36. The system of claim 34, wherein the set rate of cutting tool displacement represents a maximum displacement rate, and the controller modifies the rate of cutting tool displacement so as to avoid exceeding the maximum displacement rate.

37. The system of claim 36, wherein the predetermined displacement load profile comprises a maximum displacement load.

38. The system of claim 36, wherein the predetermined displacement load profile comprises a minimum displacement load and a maximum displacement load.

39. The system of claim 34, wherein the controller, when increasing the rate of cutting tool displacement, limits the rate of cutting tool displacement so as to avoid exceeding a maximum displacement rate.

40. The system of claim 39, wherein the predetermined displacement load profile comprises a maximum displacement load.

41. The system of claim 39, wherein the predetermined displacement load profile comprises a minimum displacement load and a maximum displacement load.

42. The system of claim 34, wherein the controller modifies the cutting tool displacement rate to achieve the predetermined displacement load profile within about 0.1 seconds to about 0.5 seconds.

43. The system of claim 34, wherein the controller calculates a maximum cutting tool displacement rate based on a set liquid flow rate, monitors an actual displacement rate, and limits the cutting tool displacement rate to the maximum cutting tool displacement rate.

44. The system of claim 43, wherein the controller calculates the maximum cutting tool displacement rate based on a size of a borehole produced by the cutting tool, a size of the cutting tool, and the liquid flow rate.

45. The system of claim 34, wherein the controller calculates liquid flow requirements for a borehole produced by the cutting tool, monitors an actual rate of liquid flow into the borehole, and adjusts an actual liquid flow rate such that the actual liquid flow rate equals or exceeds the calculated liquid flow requirements.

47. The method of claim 46, further comprising setting a speed of rotation of the cutting tool and maintaining the set speed of rotation as the displacement rate is adjusted.

48. The method of claim 46, wherein calculating the maximum cutting tool displacement rate comprises calculating the displacement rate based on a size of a borehole produced by the cutting tool, a size of the cutting tool, and the set liquid flow rate.

49. The method of claim 46, wherein automatic adjustment of the cutting tool displacement rate is accomplished within about 0.1 seconds to about 0.5 seconds.

16. A system for controlling an underground boring tool, comprising:

a rotation pump;

a pressure sensor, coupled to the rotation pump, for producing a pressure limit signal in response to a rotation pump pressure exceeding a pressure limit;

a displacement pump;

a boring tool coupled to a drill pipe, the drill pipe coupled to the rotation pump for rotating the boring tool and coupled to the displacement pump for displacing the boring tool along an underground path; and

control means, coupled to the displacement and rotation pumps, for concurrently controlling a rate of boring tool displacement along the underground path and controlling the rotation pump at a selected level in response to the pressure limit signal.

24. An apparatus for controlling an underground boring tool, comprising:

displacing means for displacing a boring tool in an axial direction along an underground path;

rotating means for rotating the boring tool at a selected rate; and

computer control means, coupled to the displacing means and rotating means, for controlling a displacing rate at which the displacing means displaces the boring tool while concurrently controlling the rotating means to rotate the boring tool at the selected rate in response to variations in underground conditions impacting boring tool progress along the underground path.

25. A method for controlling a penetration speed of an underground cutting tool, comprising:

setting a speed of rotation of the cutting tool;

setting a rate of displacement of the cutting tool;

monitoring a displacement load as the cutting tool is rotated at the set speed of rotation and displaced at the set rate of displacement; and

automatically modifying a rate of cutting tool displacement while maintaining the speed of cutting tool rotation at the set speed of rotation to achieve a predetermined displacement load profile.

34. A system for controlling a penetration speed of an underground cutting tool, comprising:

a drill pipe to which the cutting tool is coupled;

a driving apparatus coupled to the drill pipe, the driving apparatus rotating the drill pipe at a set speed of rotation and displacing the pipe at a set rate of displacement; and

a controller coupled to the driving apparatus, the controller monitoring a displacement load as the cutting tool is rotated at the set speed of rotation and displaced at the set rate of displacement, the controller modifying a rate of cutting tool displacement while maintaining the speed of cutting tool rotation at the set speed of rotation to achieve a predetermined displacement load profile.

46. A method for controlling a penetration speed of an underground cutting tool, comprising:

setting a liquid flow rate;

calculating a maximum cutting tool displacement rate using the set liquid flow rate; and

automatically adjusting a cutting tool displacement rate in response to the calculated maximum cutting tool displacement rate.