A Study on Behaviour of Magnitude-Constrained Input for Ship Maneuvering Optimal Control

Abstract

This report deals with numerical simulation concerning an optimal control problem for parallel course change maneuver of a tanker-type ship having a rudder and a bow thruster as control input. The computation for the control input based on the linear optimal regulator theory is made by taking account of magnitude constraint on the control forces generated by means of state feedback. The optimization is made by minimizing the performance function made up of quadratic form including the term of terminal state. On the other hand, time-optimal control input is evaluated. And comparison is made between the former solution with saturated state and the latter solution represented by the bang-bang function. It is confirmed that the input determined from the optimal regulator theory is fairly similar to that due to the bang-bang control, when the weighting factor for the input force is sufficiently decreased.