Apparatus and method for horizontal drilling
An apparatus and method for horizontally drilling for detecting subsurface features and avoiding such features during closed-loop control of an underground drilling machine. A horizontal drilling system includes a base machine capable of propelling a drill pipe rotationally and longitudinally underground. A cutting tool system is coupled to the drill pipe, and a control system controls the base machine. A detector is employed to detect a subsurface feature. A communication link is utilized for transferring data between the detector and the control system. The control system uses the data generated by the detector to modify control of the base machine in response to detection of the subsurface feature.
1. A system for use in horizontal directional drilling, comprising:
an above-ground locator, comprising:
a transmitter arranged to transmit a locator signal in a substantially vertical direction into a subsurface;
a receiver arrangement comprising at least one receive antenna; and
a processor; and
a beacon assembly configured for sub-surface deployment, comprising:
a beacon receiver arrangement comprising an antenna arrangement adapted to detect the locator signal transmitted from the above-ground locator;
an orientation sensor adapted to sense an orientation of the beacon assembly;
circuitry coupled to the orientation sensor and beacon receiver arrangement, the circuitry configured to produce a beacon signal used to determine a position of the beacon assembly relative to the above-ground locator in response to the locator signal received by the beacon receiver arrangement and the orientation of the beacon assembly; and
a beacon transmitter configured to transmit the beacon signal to an above-ground location;
whereby the locator receiver arrangement is configured to receive the beacon signal and the locator processor is configured to determine the position of the beacon assembly with respect to the locator using the received beacon signal.
2. The system of claim 1 , wherein the locator receiver arrangement comprises a signal antenna.
3. The system of claim 1 , wherein the locator receiver arrangement comprises first, second, and third antennas oriented orthogonal to each other.
4. The system of claim 1 , wherein the beacon assembly comprises first, second, and third antennas oriented orthogonal to each other.
5. The system of claim 1 , wherein the orientation sensor comprises an accelerometer and the orientation of the beacon assembly comprises a pitch of the beacon assembly.
6. The system of claim 1 , wherein the orientation sensor comprises an accelerometer and the orientation of the beacon assembly comprises a roll of the beacon assembly.
7. The system of claim 1 , wherein:
the beacon transmitter is configured to transmit the beacon signal containing beacon assembly orientation information; and
the locator processor is configured to determine the orientation of the beacon assembly in response to the orientation information contained in the beacon signal and produce orientation data in a form suitable for display.
8. The system of claim 1 , wherein the locator comprises a display and wherein the locator processor is configured to produce data for producing an image showing the position of the beacon assembly on the display.
9. The system of claim 1 , wherein the locator comprises a display and wherein the locator processor is configured to produce data for producing an image showing a direction of the beacon assembly on the display.
10. The system of claim 1 , wherein the locator processor is configured to calculate a depth of the beacon assembly in response to the beacon signal received by the locator receiver arrangement.
11. The system of claim 1 , wherein each of the locator signal and the beacon signal comprises an electromagnetic signal.