Position and orientation locator/monitor

• US 7,345,486 B2
• Filed: 10/12/2006
• Issued: 03/18/2008
• Est. Priority Date: 03/01/1991
• Status: Expired due to Fees

• Current Assignee: Merlin Technologies Incorporated
• Original Assignee: Merlin Technologies Incorporated
• Inventors: Mercer, John E.
• Primary Examiner(s): Aurora; Reena
• Application Number:
  US11/546,815
• Publication Number:
  US 20070030006A1
• Time in Patent Office: 523 Days
• Field of Search: 324/326, 175/45
• US Class Current: 324/326
• CPC Class Codes: E21B 47/0228 using electromagnetic energy or detectors therefor
• CPC Class Codes: E21B 47/0232 at least one of the energy sources or one of the detectors being located on or above the ground surface
• CPC Class Codes: E21B 47/024 of devices in the borehole determining slope or direction of the borehole E21B47/022
• CPC Class Codes: G01C 9/06 Electric or photoelectric indication or reading means
• CPC Class Codes: G01C 9/20 the indication being based on the inclination of the surface of a liquid relative to its container
• CPC Class Codes: G01V 3/165 operating with magnetic or electric fields produced or modified by the object or by the detecting device with electromagnetic waves G01V3/17

Abstract

The present invention provides a locator/monitor capable of locating a boring tool and monitoring the progress of the tool for control purposes. The locator/monitor may be used in expedited locating methodology and straightforward calibration techniques of the present invention. A durable and cost effective pitch sensor is also provided by the present invention. In addition, the present invention provides a slotted transmitter housing formed of an electrically conductive material, where the magnetic field generated by the transmitter is capable of penetrating to the surface.

Claims

1. In a technique for locating a boring tool which is within the ground, a method comprising:

positioning no more than one single-axis transmitter for movement with the boring tool and for transmitting an electromagnetic locating signal;

sensing at least one orientation parameter of the boring tool, using a sensor arrangement that is in electrical communication with the single-axis transmitter, to produce at least one orientation signal;

modulating said electromagnetic locating signal using the orientation signal;

transmitting the modulated electromagnetic locating signal;

moving no more than one above ground portable locator, within a region containing a borepath of the boring tool, in relation to the boring tool while receiving said modulated electromagnetic locating signal therewith to generate at least one indication which provides for approaching the boring tool with the portable locator;

establishing the orientation parameter of the boring tool as derived from the modulated electromagnetic locating signal; and

generating a display on said above ground portable locator, responsive to the received electromagnetic locating signal, including said indication and said orientation parameter.

2. The method of claim 1 wherein moving at least includes rotating the portable locator.

3. The method of claim 1 wherein generating said display includes displaying a range of the boring tool in relation to a current location of the portable locator.

4. The method of claim 1 wherein sensing includes substantially simultaneously sensing at least two orientation parameters of the boring tool with said sensor arrangement and, thereafter, said modulating causes the locating signal to convey both of the orientation parameters.

5. The method of claim 4 including selecting a pitch orientation and a roll orientation as said orientation parameters.

6. The method of claim 1 wherein sensing includes sensing at least two orientation parameters of the boring tool using a first orientation sensor and a second orientation sensor to produce a first orientation signal and a second orientation signal, respectively, and multiplexing the first and second orientation signals for use in said modulating to cause the locating signal to convey the first orientation parameter and the second orientation parameter.

7. The method of claim 1 wherein said locating signal is characterized as a dipole field.

8. The method of claim 1 wherein moving includes manipulating the portable locator in a stepwise fashion for moving the portable locator nearer to the boring tool in a staged progression.

9. The method of claim 1 wherein said modulation is performed to limit a bandwidth of the modulated locating signal to less than 2 kHz.

10. The method of claim 1 wherein sensing includes detecting a pitch orientation and a roll orientation of the boring tool and generating said display includes simultaneously displaying said pitch orientation and said roll orientation.