Minimum-time Trajectory Generation of eVTOL in Low-Speed Phase: Application in Control Law Design

Abstract

With the emergence of electric propulsive technologies in the past decades, electric vertical takeoff and landing (eVTOL) aircraft gain increasing interest, which paves the path for advanced air mobility. However, there is insufficient prior-knowledge and historical data for performance assessment of eVTOL, especially in the low-speed performance analysis, which is critical for operational safety and efficiency. To this end, this paper utilizes trajectory optimization to provide baseline reference for control design. An algorithm is proposed to generate the minimum-time trajectory of eVTOL. To guarantee computational efficiency, motion primitives are derived based on abstracted equations of motion. Thereafter, the possible types of optimal trajectories are discussed regarding mission scenarios and verified by direct collocation method. The potential application of the proposed method is showcased in the design optimization of reference model for control law. The results show that the optimized reference model reduces control resource consumption and improves transient behaviors of eVTOL aircraft.