Finite-time block backstepping control for rudder roll stabilization with input constraints

Applications of nonlinear control for rudder roll stabilization often become troublesome due to system complexity and input constraints. Meanwhile, the performance of rudder roll stabilization under wave disturbances is restricted by non -minimum phase characteristics and rudder rate scarcity. Therefore, this paper presents a finite -time block backstepping controller for roll stabilization and course keeping, a control scheme is established via transforming the original system structure together with finite -time disturbance observers which are employed to counteract the effect of ocean waves. An integral auxiliary dynamic system is designed to address input constraints and the steady-state error is then incorporated into the controller. Stability of all signals in the closed -loop system is proved by Lyapunov theory. Simulations subject to different rudder rates are carried out to illustrate the effectiveness of presented approach. Comparative analysis with nonlinear dynamic compensators demonstrates the superiority of compensating system.