Comparison of control design models and observers for dynamic positioning of surface vessels

This paper investigates some fundamental aspects of control system design for dynamic positioning of marine surface vessels. Different control design models are compared. The impact of applying linear and nonlinear models to describe the hydrodynamic damping loads are investigated, and common observer algorithms for DP are compared. The comparison includes a linear time-varying Kalman filter, an extended Kalman filter, and an unscented Kalman filter. To make the comparisons rigorous, optimization is employed to find optimal observer gains, and high-fidelity simulation data and full-scale experimental data are used to test the performance under operations/conditions with significant transient effects.