Rudder And Fin Joint Roll-damping Robust Control For Ships Based On Nautical Practice

Under the background of globalization of the contemporary world economy,90%import and export cargoes of china rely on transporting at sea.In order to reduce rolling and ensure the safety of navigation of ship,this paper further studies the control algorithm of rudder and fin joint ships based on nautical practice.The characteristics of rudder and fin stabilizer are improved based on analyzing sea trial data,and the designed robust controller not only has the satisfactory performance of course keeping and roll-damping,but the control frequency and amplitude of rudder and fin stabilizer accord those of nautical practice,whose control performance is excellent under the disturbances of model perturbation and wind and wave scale of Beaufort No.8.The main work of this paper is divided into the following points:(1)The sea trial data of Yukun ship are analyzed to improve the steering gear characteristics,and a robust controller is designed for Yukun ship based on the improved Nomoto and MMG model.It ensures the steering frequency and steering amplitude are basically consistent with these of sea trial.(2)The decoupling control algorithm,CGSA and H2 control algorithm are utilized to design the low-order controller for the ship with improved characteristics based on the optimal model reduction algorithm,and it provides a reference for reducing the hardware cost requirements of the controller in engineering application.(3)The effectiveness of improved CGSA control algorithm is verified further.Firstly,an robust controller is designed for engineer square or non-square model with time delay,whose result shows that the CGSA control algorithm is better than those in published literatures.Then,the results of further validation of the rudder-fin joint WMEC 901 warship show that the algorithm in this paper has excellent control performance,and the control frequencies of rudder and fin are in line with those of nautical practice.The roll damping between fin and rudder are combined effectively in this paper,and it not only ensures the accuracy of course stability,but further improves the performance of roll damping,which achieves the comprehensive optimal control performance.The robust controller based nautical practice provides a reference for solving the problem of frequent control and severe wear of rudder and fin stabilizer in engineering application,and has important engineering application value.