Effect study of stick-slip vibration parameters of drill string based on sliding mode controller

This paper develops a novel sliding mode control (SMC) strategy for suppressing stick-slip vibration in drill strings. A dual sliding mode surface controller is designed with proven stability through Lyapunov analysis. Systematic parameter analysis reveals that stick-slip vibration occurs only within specific input torque ranges below the maximum static friction torque, and can be eliminated by increasing rotary table velocity or viscous damping coefficient, or by decreasing weight on bit. Compared with existing controllers, the proposed SMC achieves faster stabilization (within 30 s vs 40 s in Ref. 1) while maintaining simpler structure than Ref. 2. Crucially, the controller demonstrates exceptional robustness against parameter perturbations, maintaining stability despite ±9% variations in rotational inertia and damping coefficients. The control performance on drill bit velocity proves superior to rotary table speed control, with minimal oscillation. These findings provide valuable guidance for vibration suppression and strategy optimization in drilling operations.