Research On Control Of Ship Anti-rolling And Anti-heeling Integrated System

The ship will produce a rolling or heeling motion when it is sailing on the sea or working at the port under conditions of disturbances such as wind,wave,loads.Intense rolling or heeling motion affects the seaworthiness,safety and economic efficiency of ships severely.Anti-rolling and anti-heeling integrated system is a ship comprehensive balance device composed of anti-rolling tank and anti-heeling system,which satisfies the comprehensive demand of ship anti-rolling and anti-heeling.The paper focuses on the establishment of nonlinear mathematical models of rolling and heeling motion of ship anti-rolling and anti-heeling integrated system,and the design of Backstepping Sliding Mode control of anti-rolling and anti-heeling integrated system.The main research contents of the paper include the following parts:(1)The mathematical model of disturbance of wave is established based on the spectral density theory of random sea wave.And series of simulation research of amplitude and moment of long crested random wave is carried out with various sea conditions.The mathematical model of disturbance of loads traversing,loading and unloading is established based on the gravity shift theorem.And series of simulation research of moment of loads is carried out.(2)The nonlinear mathematical model of ship rolling and heeling motion is established based on statics and dynamics theory of ship motion considering the nonlinear characteristics of ship rolling and heeling motion under conditions of wave disturbance and load disturbance.Based on the parameters of a container ship,according to the disturbance types under different sea conditions or working conditions,the simulation research of ship rolling and heeling motion is carried out respectively,and the correctness of the mathematical model is verified.(3)Considering the nonlinearity of ship rolling and heeling motion,combining features of making the system design structured of Backstepping and characteristics of insensitive to the change of disturbance and object parameter of Sliding Mode Control,a Backstepping Sliding Mode controller of anti-rolling tank and anti-heeling system is designed.(4)Considering the uncertainty of disturbance of wave and loads,combining adaptive control with the Backstepping Sliding Mode controller,a adaptive Backstepping Sliding Mode controller is designed,which does not depend on the upper bound of disturbances.(5)Considering the design of the above controller has a strong dependence on the mathematical model,combining the approximation feature of RBF neural network with the adaptive Backstepping Sliding Mode controller,a RBF neural network adaptive Backstepping Sliding Mode controller is designed,which does not depend on the precise mathematical model of object.Aiming at the controller and improvement scheme of the above design,the paper carries on the simulation research of ship anti-rolling and anti-heeling under different sea conditions and working conditions.The simulation results show that the designed controller has good robustness,adaptability and effective anti-rolling and anti-heeling efficiency.