Excavation system and method employing adjustable down-hole steering and above-ground tracking

A method of excavation, comprising:

• moving a cutting tool along an underground path using a driving apparatus;
• sensing, from above ground, one or both of a position and an orientation of the cutting tool;
• providing an adjustable steering mechanism on or in the cutting tool;
• and
• adjusting, based at least in part on one or both of the sensed position and orientation of the cutting tool, the steering mechanism while moving the cutting tool along the underground path to effect a change of orientation or heading of the cutting tool.

A method of excavation, comprising:

• moving a cutting tool along an underground path using a driving apparatus;
• sensing, from above ground, one or both of a position and an orientation of the cutting tool;
• sensing a physical property of the cutting tool as the cutting tool is moved along the underground path and producing a sensor signal indicative of the physical property;
• and
• controlling the driving apparatus in response to the sensor signal and one or both of the sensed position and orientation of the cutting tool.

An excavation system, comprising:

• an above ground tracker;
• a cutting tool coupled to a drill pipe;
• a driving apparatus coupled to the drill pipe for moving the cutting tool along an underground path;
• a sensor disposed in or proximate the cutting tool, the sensor sensing a physical property of the cutting tool as the cutting tool is moved along the underground path, the sensor producing a sensor signal indicative of the physical property;
• and
• a controller communicatively coupled to the driving apparatus, tracker, and the sensor, the controller transmitting control signals to the driving apparatus to control the driving apparatus in response to the sensor signal and in accordance with one or both of position information and orientation information produced by the tracker.