Apparatus and method for detecting a location and an orientation of an underground boring tool

• US 5,904,210 A
• Filed: 01/17/1997
• Issued: 05/18/1999
• Est. Priority Date: 01/11/1996
• Status: Expired due to Fees

• Current Assignee: Vermeer Manufacturing Company
• Original Assignee: Vermeer Manufacturing Company
• Inventors: Allen, Christopher T., Stump, Gregory S
• Primary Examiner(s): Melius, Terry Lee
• Assistant Examiner(s): Hartmann, Gary S.
• Application Number:
  US08/784,061
• Time in Patent Office: 851 Days
• Field of Search: 340/853.1, 340/853.3, 340/853.4, 340/853.5, 340/853.6, 175/24, 175/40, 175/45, 175/50, 175/26, 324/333, 324/338, 324/346, 324/351, 324/369, 342/22
• US Class Current: 175/45
• 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 47/13 by electromagnetic energy, e.g. radio frequency
• CPC Class Codes: E21B 7/046 horizontal drilling drilling with mechanical conveying means E21B7/003
• CPC Class Codes: G01S 13/74 Systems using reradiation of radio waves, e.g. secondary radar systems; Analogous systems
• CPC Class Codes: G01S 13/86 Combinations of radar systems with non-radar systems, e.g. sonar, direction finder
• CPC Class Codes: G01S 13/878 Combination of several spaced transmitters or receivers of known location for determining the position of a transponder or a reflector G01S13/874 takes precedence
• CPC Class Codes: G01S 13/885 for ground probing prospecting or detecting using electromagnetic waves G01V3/12
• CPC Class Codes: G01V 1/42 using generators in one well and receivers elsewhere or vice versa G01V1/52 takes precedence
• CPC Class Codes: G01V 3/12 operating with electromagnetic waves operating with millimetre waves G01V8/005
• CPC Class Codes: G01V 3/30 operating with electromagnetic waves

Abstract

An apparatus and method for determining a location and an orientation of an underground boring tool by employment of a radar-like probe and detection technique. The boring tool is provided with a device which generates a specific signature signal in response to a probe signal transmitted from above the ground. Cooperation between the probe signal transmitter at ground level and the signature signal generating device provided at the underground boring tool results in accurate detection of the boring tool location and, if desired, orientation, despite the presence of a large background signal. Precision detection of the boring tool location and orientation enables the operator to accurately locate the boring tool during operation and, if provided with a directional capacity, avoid buried obstacles such as utilities and other hazards. The signature signal produced by the boring tool may be generated either passively or actively, and may be a microwave or an acoustic signal. Further, the signature signal may be produced in a manner which differs from that used to produce the probe signal in one or more ways, including timing, frequency content, information content, or polarization.

Claims

1. A system for detecting a location and an orientation of an underground boring tool, comprising:

a probe signal generator, separate from the boring tool, that generates a probe signal;

a signal generator provided at the boring tool that produces a signature signal in response to the probe signal;

an orientation detector provided at the boring tool that produces an orientation signal indicative of the orientation of the boring tool;

an encoder coupled to the signature signal generator and the orientation detector that encodes the orientation signal on the signature signal to produce an encoded signature signal; and

a detector, separate from the boring tool, that detects the location and the orientation of the boring tool using the encoded signature signal.

2. The system of claim 1, wherein the detector comprises a decoder that decodes the orientation signal using the encoded signature signal.

3. The system of claim 1, wherein:

the detector is coupled to a plurality of antennas, each of the plurality of antennas receiving the signature signal; and

the detector detects a delay time associated with the signature signal being received by each of the plurality of antennas, and detects the location of the underground boring tool using the delay time.

4. The system of claim 1, wherein the detector is coupled to a receive antenna, and detects an orientation signal received by the receive antenna, the orientation signal indicating the orientation of the underground boring tool.

5. The system of claim 3, wherein the probe signal generator is coupled to a transmit antenna, the transmit antenna being supported within the antenna array.

6. The system of claim 1, wherein the probe signal generator generates one of an electromagnetic probe signal or an acoustic probe signal.

7. The system of claim 1, wherein the probe signal generator comprises a ground penetrating radar system.

8. The system of claim 1, wherein the signature signal is passively generated by the signature signal generator.

9. The system of claim 1, wherein the signature signal is actively generated by the signature signal generator.

10. The system of claim 1, wherein a polarization of the signature signal is orthogonal to a polarization of the probe signal.

11. The system of claim 1, wherein the signature signal has a characteristic in one of the time domain or the frequency domain.

12. The system of claim 1, further comprising a location unit to determine a geographical location of the underground boring tool.

13. An apparatus for use with an underground boring tool and an above-ground probe and detection unit for detecting a location and an orientation of the underground boring tool, the apparatus comprising:

a signal generator provided at the boring tool that produces a signature signal in response to a probe signal received from the above-ground probe and detection unit;

an orientation sensor provided at the boring tool that produces an orientation signal indicative of the orientation of the boring tool; and

an encoder coupled to the signature signal generator and the orientation sensor that encodes the orientation signal on the signature signal to produce an encoded signature signal;

whereby the encoded signature signal is used by the above-ground probe and detection unit to determine the location and orientation of the underground boring tool.

14. A device for use with an underground boring tool and an above-ground probe and detection unit for detecting an orientation of the underground boring tool, the device comprising:

an orientation apparatus mounted to the boring tool that produces an output signal in response to a probe signal received from the above-ground probe and detection unit, the output signal indicative of an orientation of the boring tool and a location of the boring tool;

whereby the output signal of the orientation apparatus is used by the above-ground probe and detection unit to determine the orientation and location of the underground boring tool.

15. The device of claim 14, wherein the orientation apparatus includes a plurality of orthogonally arranged tilt sensors.

16. The device of claim 14, wherein the orientation apparatus includes a plurality of signature signal devices provided about a periphery of the boring tool, each of the signature signal devices generating a unique signature signal during boring tool rotation.

17. The device of claim 14, wherein the orientation apparatus includes a plurality of transmission lines provided about a periphery of the boring tool, each of the transmission lines generating a unique signature signal in response to the probe signal received from the above-ground probe and detection unit.

18. The device of claim 14, wherein the orientation apparatus includes a tilt sensor including an elongated rail which electrically communicates with a movable contact that moves in response to a change in boring tool orientation, a magnitude of movable contact movement corresponding to a magnitude of the change in boring tool orientation.

19. The device of claim 18, wherein the movable contact comprises a bead of mercury.

20. An apparatus for use with an underground boring tool and an above-ground probe and detection unit for detecting a location and a pitch of the underground boring tool having a longitudinal axis and an outer periphery, the apparatus comprising:

a plurality of signature signal generating devices provided about the periphery of the boring tool, each of the signature signal generating devices generating a unique signature signal during boring tool rotation in response to the probe signal;

a pitch sensor provided on the boring tool that senses a change in pitch with respect to the longitudinal axis of the boring tool and produces a pitch signal indicative of the change in boring tool pitch; and

an encoder that encodes the pitch signal on the signature signal to produce an encoded signature signal;

whereby the above-ground probe and detection unit uses the encoded signature signal to detect the location and the pitch of the boring tool.

21. A system for detecting a location and an orientation of an underground boring tool, comprising:

a driving apparatus that drives the boring tool so as to produce an underground path;

a probe signal generator, separate from the boring tool, that generates a probe signal directed at the boring tool;

a signature signal generator, mounted to the boring tool, that produces a signature signal at the boring tool in response to the probe signal;

an orientation apparatus, mounted to the boring tool, that produces an orientation signal indicative of an orientation of the boring tool;

an encoding device, coupled to the orientation apparatus and the signature signal generator, that encodes the orientation signal on the signature signal;

a detector that detects the location and the orientation of the boring tool using the encoded signature signal; and

a control apparatus, coupled to the driving apparatus, that controls the drive rate and direction of the boring tool in response to the detected boring tool location and orientation.

22. A method for detecting a location and an orientation of an underground boring tool using a probe signal generated from an above-ground probe and detection unit separate from the boring tool, the method including the steps of:

generating a signature signal at the boring tool in response to the probe signal;

producing an orientation signal at the boring tool indicative of an orientation of the boring tool; and

transmitting the signature signal and the orientation signal;

whereby the signature and orientation signals transmitted from the boring tool are received and used by the above-ground probe and detection unit to detect the location and orientation of the boring tool.

23. The method of claim 22, including the further step of encoding the orientation signal on the signature signal.

24. The method of claim 22, wherein the generating step includes the step of passively generating the signature signal.

25. The method of claim 22, wherein the generating step includes the step of actively generating the signature signal.

26. A method for controlling an underground boring tool, comprising:

driving the boring tool so as to produce an underground path;

producing a probe signal;

generating a signature signal at the boring tool in response to the probe signal;

producing an orientation signal at the boring tool indicative of an orientation of the boring tool;

transmitting the signature signal and the orientation signal;

detecting a location and the orientation of the boring tool using the signature and orientation signals transmitted from the boring tool; and

controlling the drive rate and direction of the boring tool in response to the detected signature and orientation signals.