ABSTRACT
A system is underactuated if there are a fewer number of independent actuators than the degrees of freedom. This chapter investigates the fault-tolerant tracking control for an underactuated surface vessel without actuator redundancy. In a discontinuous time-varying feedback controller for a nonholonomic system and control scheme is applied to an underactuated surface vessel. The chapter considers designing a universal controller for the global tracking control problem of a surface vessel when sway force suffers from nonperiodical actuator failure and when the dynamics of the surface vessel switches between an underactuated system and an actuated system by using the Lyapunov's direct approach. It advocates Lyapunov's direct approach because it has become a standard method for nonlinear control design. This methodology could also be extended to other MIMO nonlinear systems whose actuators suffer from partial or total failure.
