Abstract: Apparatus for controlling a drilling machine to drill a series of parallel holes, where the drilling machine comprises a carrier vehicle movable over the terrain, a boom mounted on the vehicle for movement side to side on the vehicle, a mast carried on an outer end of the boom and movable about two separate axes relative to the end of the boom, includes a first sensor responsive to an azimuth angle relative to the earth's magnetic north direction and two additional sensors, which are used to measure the two inclinations relative to two vertical planes transverse to and longitudinal of the boom. The sensor system is mounted in an housing on the mast close to the longitudinal center of the mast and offset to the side. A controller calculates from the sensed values of the azimuth and inclination angles required target angles for the mast for drilling each hole.

Abstract: Apparatus for controlling a drilling machine to drill a series of parallel holes, where the drilling machine comprises a carrier vehicle movable over the terrain, a boom mounted on the vehicle for movement side to side on the vehicle, a mast carried on an outer end of the boom and movable about two separate axes relative to the end of the boom, includes a first sensor responsive to an azimuth angle relative to the earth's magnetic north direction and two additional sensors, which are used to measure the two inclinations relative to two vertical planes transverse to and longitudinal of the boom. The sensor system is mounted in an housing on the mast close to the longitudinal center of the mast and offset to the side. A controller calculates from the sensed values of the azimuth and inclination angles required target angles for the mast for drilling each hole.