Attitude Control Method for Drilling Tools Accounting for Fluctuations in Rate of Penetration and Time-Varying Delays

The attitude control method for downhole directional drilling tools has been studied. To address the adverse effects of rate of penetration fluctuations and time-varying delays on the attitude control system, a comprehensive control system was designed by integrating the inclination and azimuth control loops of the drilling tools. The required gain of the controller was determined by conducting a stability analysis of the attitude closed-loop system using Lyapunov functional and linear matrix inequality methods. The effectiveness and applicability of this method were verified using typical drilling tools. Finally, this system demonstrates strong robustness and adaptability, significantly enhancing the accuracy and efficiency of drilling tool attitude control.