Adaptive Observer-based Fault-Tolerant Control for Actuator Faults in Quadrotor UAV

This paper deals with the design of a novel Active Fault Tolerant Control (AFTC) algorithm for an underactuated quadrotor UAV system in the presence of actuator faults. A robust control strategy based on the backstepping technique is used to compensate for the fault effect in the system. In order to estimate the fault magnitude, an adaptive observer is developed based on a nonlinear dynamic model of the quadcopter. This dynamic model, considering high-order nonholonomic constraints as well as various physical phenomena that can influence its dynamics, is briefly presented. According to a Lyapunov-based stability study, the suggested control strategy design preserves the stability of the closed-loop dynamics of quadrotor aircraft even in the presence of actuator failures. As shown by the numerical simulation results, the suggested control laws exhibit excellent tracking performance.