Dynamic Positioning Control for Accommodation Vessels With Input Time Delay

Abstract

Offshore operations have been moving towards ultra-deep waters where rich resources are detected and mined in a challenging environment. Dynamic Positioning (DP) control remains a challenge due to time delay in the input control and unknown wave or wind disturbance. In this paper, robust control is proposed for the DP of an accommodation vessel in the presence of the input time delay. In order to overcome the unknown dynamics and external disturbances, a robust controller with predefined tracking constraints is developed to guarantee a safe operation. Time delay caused by the control input is also considered on the predictor-based method. The boundedness of all closed-loop signals is demonstrated via rigorous Lyapunov analysis. Simulation studies help demonstrate outstanding performance and feasibility of the proposed control structure.

Keywords

• Dynamic positioning
• robust control
• prescribed performance
• input delay