Fault Estimation Method for Nonlinear Time-Delay System Based on Intermediate Observer-Application on Quadrotor Unmanned Aerial Vehicle

Abstract

In this paper, the problem of actuator and sensor faults of a quadrotor unmanned aerial vehicle (QUAV) system is studied. In the system fault model, time delay, nonlinear term, and disturbances of QUAV during the flight are considered. A fault estimation algorithm based on an intermediate observer is proposed. To deal with a single actuator fault, an intermediate variable is introduced, and the intermediate observer is designed for the system to estimate fault. For simultaneous actuator and sensor faults, the system is first augmented, and then two intermediate variables are introduced, and an intermediate observer is designed for the augmented system to estimate the system state, faults, and disturbances. The Lyapunov–Krasovskii functional is used to prove that the estimation error system is uniformly eventually bounded. The simulation results verify the feasibility and effectiveness of the proposed fault estimation method.

Combined Observer-Based State Feedback and Optimized P/PI Control for a Robust Operation of Quadrotors

“…Another challenge that has been tackled in the literature is dealing with actuator faults, as in [12], where the authors have combined model predictive control and reinforcement learning to detect and compensate faults of a quadrotor during trajectory tracking. The same objective has been treated with the help of linear control theory in [13][14][15], where the authors exploited the linear matrix inequalities (LMIs) tool to solve H ∞ problems for different purposes such as fault diagnosis or state estimation, while the authors in [16] have exploited a Kalman filter to propose a fault detection and diagnosis scheme to detect and isolate actuator faults in presence of external disturbances. In contrast to this, the authors of the reference [17] have exploited an extended Kalman filter.…”

H∞ Robust Fault-Tolerant Control of a Six-Rotor UAV Containing Sensor Faults and Actuator Non-Affine Faults

“…I N today's society, the environment of human industrial production operations has not only been limited to a fixed range, but also the production operation environment is becoming larger and more complex, which requires UAVs to assist in the completion of production operations. Thanks to the rapid development of modern communication technology, certain achievements have been made in the field of UAVs, such as the literature [1]- [3] and their references. Six-rotor UAVs are highly favored by researchers for their excellent flexibility and stability, and moreover, they play an important role in practical production work [4], [5].…”