Fault Tolerant Control for an Unmanned Surface Vessel Based on Integral Sliding Mode State Feedback Control

In the complex ocean environment, the thruster faults may affect the stability of unmanned surface vessel (USV). So it is really important to study the problem of USV fault tolerant control. Under the framework of integral sliding mode technology, this work presents a fault tolerant control problem for USV. First, a comprehensive thruster fault model with total faults, partial faults, hard-over faults, bias faults, and time-varying stuck faults, is established. Then, an integral sliding mode surface and sliding mode controller with fault estimation are designed. Through LMI technology and Lyapunov stability theory, the stability of sliding mode has been proved. Compared with the existing results, the oscillation amplitudes of yaw angle and yaw velocity can be suppressed from the every beginning. Finally, simulation results demonstrate that the proposed integral sliding mode fault tolerant control algorithm is effective.