Abstract: The invention relates to a drilling system. It includes, in combination, a drilling derrick by means of which a string of drill rods can be suspended from a hoist, a motorized drilling head at the end of the hoist, means for bringing a drill rod into position to be added to the drill string from a stack, a motor to drive the hoist, a reversible control for the said hoist motor, sensors for determining the state of the system, and a programmable robot to supply the set points to the hoist motor control according to signals furnished by the said system state sensors.