Handling roll constraints for path following of marine surface vessels using coordinated rudder and propulsion control

The problem of path following for marine surface vessels using coordinated rudder and propeller control is addressed in this paper. The same problem was addressed in using model predictive control (MPC) to deal with roll constraints. The goal of this study is to investigate the benefits as well as the associated cost, in terms of both control performance and computational complexity, of using the propeller as the second control actuator for solving the path following problem. The proposed MPC design is based on a time varying linear model, and the roll limitation is enforced as a hard constraint. The performance evaluation of the MPC using the rudder and propeller is carried out on a nonlinear 4 degree-of-freedom surface vessel model. The simulation results verify the effectiveness of the resulting controller and show the advantage of the proposed controller over the one using a rudder as the sole actuator. Sensitivity of the performance over the key design parameters is also investigated to provide design guidelines.