Integral Sliding Mode Control Enhanced by an Adaptive Double-Power Reaching Law for UAV Systems

This study proposes a robust flight control framework for quadrotor unmanned aerial vehicle (UAV) trajectory tracking based on Integral Sliding Mode Control (ISMC) enhanced by an Adaptive Double-Power Reaching Law (ADPRL). The proposed controller is designed to improve robustness against lumped uncertainties, external disturbances, and nonlinear UAV dynamics while reducing chattering commonly associated with conventional Sliding Mode Control (SMC). To prevent unnecessary gain escalation near the sliding manifold, a practically bounded adaptive reaching mechanism incorporating sigma-modification, dead-zone regulation, and saturation-based switching regularization is introduced. The controller is formulated within a dual-loop position–attitude control architecture, and its stability properties are examined using a Lyapunov-based approach. Comparative MATLAB simulations are conducted against representative baseline controllers, including SMC, ISMC, STSMC, and ADRC. The results show that the proposed ISMC-ADPRL controller achieves the lowest thrust RMS value of 9.5297 N while maintaining competitive trajectory-tracking performance, indicating a practical balance between tracking accuracy, control-effort reduction, and smoother actuation.