262 A ship maneuvering system for automatic berthing : Control performance enhancement by optimization of a ship motion model

2015 ◽  
Vol 2015.64 (0) ◽  
pp. _262-1_-_262-2_
Author(s):  
Ryoma ARIKI ◽  
Naoki MIZUNO
Keyword(s):  
Performance Enhancement ◽  
Ship Motion ◽  
Motion Model ◽  
Control Performance ◽  
Ship Maneuvering

scholarly journals A Fully Nonlinear, Dynamically Consistent Numerical Model for Ship Maneuvering in a Seaway

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Ray-Qing Lin ◽  
Weijia Kuang
Keyword(s):  
Experimental Data ◽  
Time Series ◽  
Adaptive Algorithm ◽  
Ship Motion ◽  
Frequency Variation ◽  
Physical Domain ◽  
Motion Model ◽  
Ship Maneuvering ◽  
Fully Nonlinear ◽  
Ship Tracks

This is the continuation of our research on development of a fully nonlinear, dynamically consistent, numerical ship motion model (DiSSEL). In this paper we report our results on modeling ship maneuvering in arbitrary seaway that is one of the most challenging and important problems in seakeeping. In our modeling, we developed an adaptive algorithm to maintain dynamical balances numerically as the encounter frequencies (the wave frequencies as measured on the ship) varying with the ship maneuvering state. The key of this new algorithm is to evaluate the encounter frequency variation differently in the physical domain and in the frequency domain, thus effectively eliminating possible numerical dynamical imbalances. We have tested this algorithm with several well-documented maneuvering experiments, and our results agree very well with experimental data. In particular, the numerical time series of roll and pitch motions and the numerical ship tracks (i.e., surge, sway, and yaw) are nearly identical to those of experiments.

Stabilization of the Ship Motion by Restricted Control

2020 ◽  
Vol 28 (4) ◽  
pp. 106-123
Author(s):  
G.M. Dovgobrod ◽  
Keyword(s):  
Feedback Linearization ◽  
Control Algorithm ◽  
Linearization Method ◽  
Ship Motion ◽  
Control Law ◽  
Motion Model ◽  
Lateral Deviation ◽  
Bounded Curvature ◽  
Trajectory Attractor ◽  
Singularity Point

. The article presents an algorithm for controlling the motion of an insufficiently controlled ship along a trajectory with a continuous bounded curvature, based on the feedback linearization method. The algorithm allows restricting the control signal, while the state vector of the ship motion model does not approach the singularity point of the control law. The control algorithm returns the ship to the specified trajectory-attractor at any lateral deviation of the ship from the specified trajectory.

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