A Disturbance Observer-Based Control of Drilling Vibrations

This paper presents two control strategies to suppress the unwanted torsional vibrations occurring in a drill string system. The control scheme uses a disturbance estimation procedure, which ensures the rejection of this uncertainness, allowing the robustness improvement of closed loop system. A constrained predictive command obtained by solving a minimization problem and a linearized control are derived, and validation results are presented to prove the effectiveness of the proposed scheme.