A fault estimation and sliding-mode fault-tolerant control method based on the reduced-order Kalman filter is
proposed to deal with the time-varying nonlinear faults of the underwater vehicle actuators. Firstly, states of the underwater
vehicle subsystem decoupled from the faults are estimated by the reduced-order Kalman filter, and states of another subsystem
affected by faults can be measured. Then the fault informations of the time-varying actuators can be obtained from two
subsystems states. Finally, fault-tolerant control of the underwater vehicle is achieved by reconfiguring the output of sliding-
mode controller according to faults estimation. The numerical simulation results show the effectiveness of the proposed
algorithm for fault identification and fault-tolerant control.