Fault-tolerant control allocation for a bio-inspired underactuated AUV in the presence of actuator failures: Design and experiments

In this paper, we present the mathematical design and implementation of a fault-tolerant control scheme for a bio-inspired underwater robot with four flexible fins. The proposed active fault-tolerant control scheme re-configures the force allocation matrix using the elimination of column method, depending on which fin actuator is faulty. The proposed method allows to decouple the 6-DOF controllable underwater vehicle using the remaining three fins. The efficacy of the proposed method is assessed experimentally for trajectory tracking of an ellipsoidal-shaped trajectory using two different controllers, namely PID control and Sliding Mode control. The obtained results show that the combination of a sliding mode controller with the proposed fault-tolerant control allocation approach ensures an efficient trajectory tracking control performance when faults occur. •In this work, we present a novel fault-tolerant control (FTC) for fin-actuated AUVs.•We address challenges of highly coupled, nonlinear actuation systems.•We assess the proposed FTC scheme experimentally in controlling 3 degrees of freedom.•We Carry out comprehensive analysis covering various fault conditions.