A Yaw-roll Coupling Suppression Control Method for eVTOL Aircraft with Nonuniform Propulsion Layout

In recent years, electric vertical take-off and landing (eVTOL) aircraft have become a primary focus in urban air mobility research. eVTOL aircraft integrate the advantages of multirotor and fixed-wing designs, enabling vertical take-off and landing as well as efficient long-range cruising, thereby offering substantial research value. During vertical take-off and landing, their control resembles that of multirotor aircraft; however, the nonuniform propulsion layout and large inertia induce yaw-roll coupling during yaw maneuvers. Additionally, yaw control via differential rotor speed is inefficient, often leading to actuator saturation and increased risks of attitude instability. To address these challenges, this study derives the yaw motion dynamics for eVTOL with nonuniform propulsion layout and proposes a yaw control law with cross-coupling compensation to mitigate attitude coupling during yaw maneuvers. A simplified approach is introduced, leveraging pseudo-control command saturation design to maintain stability at high yaw angular velocities. Compared to methods based on the convex optimization algorithm or the redistributed pseudo-inverse algorithm, the proposed method reduces computational complexity and is readily applicable to practical flight scenarios. Simulation results demonstrate that the proposed approach effectively mitigates attitude coupling in yaw movements and expands the range of achievable yaw angular velocity commands.