Integrated Fault-Tolerant Control of an Over-Actuated Aircraft Using Optimal Control Allocation and Robust Sliding Mode Observers

Abstract

Many modern aerospace systems are inherent overactuated regarding their control effectors. This results in an analytical actuator redundancy, which can be utilizied for reallocating control signals among remaining healthy effectors in the face of actuator faults, thus increasing the overall operational safety. In such an active fault-tolerant control system a module for fault detection, isolation and identification is therefore needed. On the other hand, the distribution of the redundant control signals in a fault-free case can also be used to fulfill further objectives regarding the optimization of certain system properties. This paper proposes an integrated fault-tolerant control strategy for actuator faults, combining optimization-based control allocation techniques with sliding mode observers for robust fault detection and reconstruction. The ADMIRE (Aero-Data Model In Research Environment) aircraft benchmark model is used to demonstrate the good closed-loop performance of the presented methods.