The Longitudinal Stability Research Of Catamaran With Active T-foil

Catamaran as a more mature ship,have been widely used in various fields,its excellent performance has been unanimously affirmed by the academic community,because the catamaran is composed of two slender hull,wave resistance is small.The high-speed catamaran has also been vigorously developed.However,with the speed of the catamarans being increasing the vertical movement of the intensity is gradually increasing,this negative effect seriously hampered the development of high-speed catamaran.Therefore,the study of the longitudinal stability of the catamaran has important significance,this paper uses the active T-foil as the attached roll device.The model predictive control algorithm is used to control the angle of attack of the active T-foil,and doing simulation and analyzing about the catamaran with the T-foil by random wave interference.This paper first designs the active T-foil that the catamaran needs to adapt,including the selection of the T-foil airfoil,the adaptation of the T-foil area and the aspect ratio;and when the T-foil and the catamaran are combined the choice of the pillar and the installation location and the determination of the angle of attack;finally,selecting the hydraulic drive as the active T-foil drive,according to the need to install the actual ship.Then,a nonlinear model of the longitudinal motion of the catamarans is established by using the rigid body motion theorem and the law of moments of moments relative to the rigid body motion.And the Jacobi linearization method is used to simplify the linear state space model for the controller design.At the same time,the time-domain model of random sea waves under specified sea conditions is established,according to the superposition principle of random wave energy spectrum,and the reason of seasickness is introduced,the empirical formula of seasickness is given as the basis of the controller design.Finally,MATLAB simulation is carried out on the experimental data of a concrete model of catamaran ratio reduction.First of all,the transfer function of disturbance and disturbance torque of random ocean waves under fixed sea condition is simulated by MATLAB system identification toolbox.The change of catamaran’s heave pitch and the suppression of seasickness were analyzed in the case of bare ship and the T-foil with controller.The improvement of the model predictive control for the longitudinal motion of catamarans is summarized.The results show that the algorithm that this paper puts forward is feasible and can do it well..