Directional drilling machine and method of directional drilling

摘要

A system, apparatus and method for automatically limiting the thrust force applied to a drill string during an underground boring process, in order to prevent the deformation or collapse to the drill rods due to reaching the yield point of the rods. One or more drill string characteristics that have an impact on the yield point of the drill string, or portions of the drill string, are determined. The yield point of the drill string or portion is computed, where the yield point is computed as a function of the drill string characteristics. The thrust force imparted to the drill string is adjusted in response to the computed yield point.