Finite-time Target Tracking for an Autonomous Submarine in Three-Dimensional Space by Using Dynamic Surface Control

In this paper, the control problem of a finite-time target tracking for an underactuated autonomous submarine is considered in three-dimensional space in the presence of unknown disturbances caused by waves and ocean currents via Dynamic Surface Control (DSC) method. At first, computational complexities of the backstepping method are greatly reduced by employing the DSC technique. Next, by designing a finite-time controller, it can be demonstrated that system errors converge to a small region containing the origin in a finite time. An adaptive robust controller is employed to compensate for unknown vehicle parameters and uncertain nonlinearities. The stability of the proposed controller is demonstrated by an analysis based on Lyapunov theory. Finally, the tracking performance of the proposed control scheme is simulated by MATLAB software and its effectiveness is shown as well.