A Self-Optimizing Control System for Hard Rock Percussive Drilling

The derivation and application of a self-optimizing control system for percussive drilling of hard rock is presented. The control system superimposes an oscillating force signal onto the drill feed force and demodulates the signal from the drill rotational torque. The resultant demodulated signal is then used to control the drill, allowing real-time maximization of penetration rate, minimum hole deviation, and measurement of rock characteristics regardless of drilling conditions. The control system allows the drill to adapt to changing rock conditions. Testing has proven the control to be reliable and to increase drilling efficiency.