Robust-powered yaw control of aircraft with distributed electric propulsors

Abstract

This paper presents two robust-powered yaw control methods for distributed electric propulsion (DEP) aircraft. These two methods are based on a robust servo linear-quadratic regulator (RS-LQR), employing (1) a hybrid yaw control utilising both aerodynamic and electric forces and (2) a fault-tolerant control (FTC) working for the event of electric propulsor failure. The hybrid yaw controller optimally combines aerodynamic forces and electric propulsion by adjusting control weightings to improve tracking performance and robustness. Its performance is measured via settling time, maximum overshoot and a robustness measure quantified through the minimum singular value of the return difference matrix. In parallel, the FTC is initiated by a real-time fault detection algorithm that identifies faulty propulsors through the monitoring of yawing moment deviations, followed by the control being reconfigured to redistribute control effort among the remaining propulsors. As part of the FTC algorithm, a logic of equalising the yawing moment is introduced to minimise the impact of propulsor failures. The proposed methods are validated through a hardware-in-the-loop (HILS) simulation that involves Raspberry Pi and the FlightGear flight simulator. Results show significantly improved yaw tracking performance and system robustness.