Control Saturation Analysis of Second-Order Integral System for the Application of eVTOL

Electric Vertical Takeoff and Landing (eVTOL) aircrafts have garnered considerable interest as a fundamental component of urban air mobility. However, the saturation is likely to happen due to the large mass and rotational inertia, especially when motor failure occurs in the eVTOL system. Therefore, this article tries to analyze the characteristics of saturation performance of control systems, particularly the second-order integral system, which is the most common system in trajectory following and control. Firstly, the overshoot condition of the saturation system is derived by phase portrait analysis. Then, the relation of the overshoot ratio with the command input, control bandwidth, and input constraints is given. After analyzing the saturation characteristics, the conclusion is applied to design the eVTOL controller for enhancing control performance and satisfying airworthiness.