Design and Flight Test of a Kalman Filter-based Incremental Nonlinear Dynamic Inversion Attitude Controller for eVTOL UAVs

In this study, an incremental nonlinear dynamic inversion (INDI) control method was applied to the attitude control loop of an electric vertical takeoff and landing (eVTOL) aircraft to ensure stable and robust flight performance under various disturbance conditions. The INDI controller reduces system dependency on accurate system models and utilizes real-time sensor feedback to enhance disturbance rejection and robustness. A Kalman filter is used to estimate angular acceleration in real time, enabling the effective implementation of the INDI control law. The designed controller was integrated into the flight control computer of a lift-cruise-type eVTOL aircraft and flight tests were conducted under wind disturbance conditions with wind velocities of 3 to 5 m/s. The results demonstrate that the proposed INDI controller outperforms a conventional PID controller in terms of attitude stability and disturbance rejection capability.