Research On Active Control Of Ship Floating Raft Isolation System

The vibration and radiated noise generated by the operation of mechanical power equipment on the ship have great harm,which seriously reduces the concealment and combat capability of the warship.Vibration isolation technology for power equipment can effectively reduce the vibration and noise transmitted to the hull structure,which is one of the most important technical means for vibration and noise reduction of ships.Common vibration isolation systems mainly include single-layer,double-layer and floating raft isolation systems.However,the traditional vibration isolation system belongs to passive control.when the structure is determined,the vibration isolation effect is determined,and cannot adapt to the changes of working conditions;and due to the structural limitations,it is difficult to achieve good vibration isolation effect for low-frequency vibration.The active vibration isolation technology developed from control technology and vibration isolation technology has the advantages of good vibration isolation effect and strong adaptability,which is one of the important development directions in the field of ship vibration isolation.This paper first established the dynamic model of single-layer vibration isolation system and double-layer vibration isolation system,analyzed the vibration transmission characteristics of these two types of vibration isolation systems;and studied the active vibration isolation technology of the single-layer vibration isolation system with three active units of displacement,velocity and acceleration.Next,taking the double-layer vibration isolation system as the research object,the double-layer active vibration isolation system model is established.In view of the known model and excitation signal of the double-layer vibration isolation system,the FXLMS control algorithm is used to design the feedforward control system,and the simulation of the adaptive feedforward control of the double-layer vibration isolation system is carried out.In view of the fact that the excitation source often changes in the actual work and it is difficult to establish the accurate mathematical model of the whole system,the fuzzy control algorithm is used to design the feedback control system,and the simulation research is carried out at the same time.The results show that compared with the passive control,the vibration isolation effect of the two active control systems is greatly improved.Then,the rigid-flexible coupling model of the floating raft vibration isolation system is established by the combination of ADAMS dynamic analysis software and ANSYS finite element analysis software,and the modal analysis and harmonious response analysis of the established model are carried out.In order to provide guidance and reference for the design of the floating raft vibration isolation system,this paper also uses the output power flow of the floating raft body as the vibration isolation evaluation index to study the influence of the structural parameters of the floating raft vibration isolation system on the vibration isolation effect.Finally,according to the established rigid-flexible coupling model of the floating raft vibration isolation system,a fuzzy control system is designed,and the ADAMS and MATLAB software are used for joint simulation analysis to study the effectiveness of the fuzzy control algorithm in the active control of the floating raft vibration isolation system.The simulation results show that the active control of the floating raft vibration isolation system has a better vibration isolation effect than passive control.