Abstract This article presents the development and implementation of incremental nonlinear dynamic inversion (INDI), integrated with a proportional-derivative (PD) controller, to enhance stability and reference tracking during the takeoff, hover, and landing phases of an eVTOL (electric vertical takeoff and landing) vehicle. Simulation results indicate that INDI, combined with a PD controller tuned with natural frequencies between 0. 1 0. 1 and 3. 0~ rad/s 3. 0 rad / s and damping ratios near 1. 0 1. 0, yields an overshoot below 20\% 20 %. The steady-state time is less than 2~s 2 s for the attitude variables and less than 10~s 10 s for altitude. The rise time (10–90% of the final value) is consistent with and shorter than the steady-state time, meeting the performance requirements for vehicle operation and ensuring stable behavior during takeoff, hover, and landing. The system also exhibits robustness to parametric uncertainties (in particular, 10\% ± 10 % variations), maintaining bounded tracking errors within the vertical-flight envelope considered. The study further includes hardware-in-the-loop experiments to evaluate the behavior of the control law implemented on an STM32F4 microcontroller. Finally, a simulation-based stability and robustness analysis confirms that the closed-loop system remains stable provided that model uncertainties remain moderate.
Cortéz et al. (Mon,) studied this question.