Predictive longitudinal following control for ship platoon considering diesel engine driven propeller reversal

Abstract

To realize synchronous movement of ship platoons, a cooperative Longitudinal Following Control (LFC) method based on Model Predictive Control (MPC) considering the diesel engine driven propeller reversal is studied. To describe the complex process of diesel engine driven propeller rotation, we propose a diesel engine driven propeller rotation model with taking engine fuel injection signal as an input and rotation speed as an output, and the rotation direction switching logic is expressed with a function. Then, a unified LFC predictive model is proposed in combination of the propeller rotation model, propeller propulsion model and ship following model. An objective function considering multiple constraints, energy consumption, and platoon performance is designed, and a dynamic optimization problem is solved with a nonlinear optimization function, where a discrete process (rotation direction switching) and a continuous process motion control are handled simultaneously. Four cases have been studies in simulation experiments with a standard container ship and 12K98ME diesel engine. The results show that the proposed MPC based LFC considering the Propeller Reversal (MPC-LFC-PR) can effectively achieve the ship platooning control in comparison of the MPC based LFC Not considering the Propeller Reversal (MPC-LFC-NPR) and the Proportional–Integral Derivative based LFC considering the Propeller Reversal (PID-LFC-PR).