Control Study Of Large Ship Maneuvering Based On LQR

With the shipping industry's prosperity and the increase in the size of merchant ships,the influence of environmental disturbance forces(flow and wind)on ship maneuvering becomes more and more prominent,the maneuverability control of the ship under bank effect and the wind load has gradually become a research hotspot.Based on LQR controller,this paper studies the course keeping ability of ship maneuvering motions from two parts,both the control of motion in confined waters and the prediction and control of maneuvering in the wind load.The control of motion in confined waters,firstly the Abkowitz model is used to obtain linear ship maneuvering motion equation,and the linear state equation of the ship model of the KVLCC2 ship model in confined waters is derived by interpolating the suction force and moment in the linear ship maneuvering motion equation,in which the hydrodynamic derivatives of the ship model is obtained by the planar motion mechanism tests in circulating water channel.Then the LQR controller is designed based on the state space equation with Matlab as the simulation platform,and compared with pole placement control method,the superiority of LQR controller in traverse and steering control is verified.Finally,the LQR control of the ship model on the various separation distances is studied,the results show that the LQR controller can effectively adjust and control the course of the ship through the rudder and deceleration,and maintain the ship's course keeping ability.The prediction and control of maneuvering in the wind load,Firstly,we interpolate the wind load into the MMG model to derive ship maneuvering motion equations of a large container ship under wind load,in which the hydrodynamic derivatives of the ship model and the wind load is respectively obtained by the planar motion mechanism tests in circulating water channel and the Fujiwara Minwen method.Based on the maneuvering equations above,the turning motion and zigzag motion under wind load are simulated.The results show that the ship's turning performance and follow-up steering are both worse.Finally,the LQR control of the ship under various wind speeds is investigated,and good control performance of LQR is verified.