Adaptive Nonlinear Dynamic Inversion with Ground Taxiing Dynamics for Trajectory Tracking and Safe Autonomous Take-Off/Landing of Fixed-Wing UAVs

The design of control systems for aircraft autonomous takeoff and landing, as well as full-flight-envelope operations—including taxiing, takeoff, climb, cruise, descent, and landing—presents significant challenges. These challenges arise from the strong nonlinear coupling between airframe dynamics and landing-gear–ground interactions, phase-specific disturbances (e.g., uneven runways and aerodynamic uncertainties), and the difficulty in coordinating trajectory tracking, attitude stability, and landing gear load management across all phases. To address these issues, this paper proposes a ground-contact-aware adaptive nonlinear dynamic inversion (GCA-ANDI) control system for fixed-wing UAVs with tricycle landing gear. Unlike conventional cascade PID or pure NDI methods, which lack phase awareness or explicit ground interaction modeling, GCA-ANDI integrates real-time ground contact perception and phase-adaptive mechanisms. This approach establishes a unified control system framework that synergizes high-level trajectory tracking, attitude stabilization, and landing gear load regulation. Simulation results demonstrate that the proposed GCA-ANDI control system outperforms benchmark methods across the full flight envelope. It achieves significant improvements in tracking accuracy, effectively suppresses attitude fluctuations induced by ground interactions or aerodynamic uncertainties, balances multi-wheel load distribution, and reduces structural impact during takeoff and landing. This study enhances robustness against phase-specific disturbances and provides a theoretical and technical foundation for high-precision, safe, and reliable full-flight-envelope autonomy in aircraft.