Design and implementation of a fault-tolerant controller using control allocation techniques in the presence of actuators saturation for a VTOL octorotor

摘要

Fault-tolerant control systems are vital in many industrial systems. Actuator redundancy is employed in advancedcontrol strategies to increase system maneuverability, flexibility, safety, and fault tolerability. In this paper, a faulttolerantcontrol scheme is proposed to make an over-actuated octorotor robust, against actuators fault and saturation.A sliding mode observer is employed to determine the actuators condition. Then, a fault-tolerant control based onthe control allocationmethodology is proposed to distribute the control signals between the actuators by consideringtheir condition. In a nonlinear system, an actuator fault can lead to the saturation of other actuators and steady-stateerrors that can cause closed-loop instability. Hence, the proposed control scheme corrects the actuator signals in away that their limitations are considered. Finally, experimental studies are carried out and a comparison study isprovided.