Research On Active Control Of Ship Double-layer Vibration Isolation And Optimal Configuration Of Actuator

The harmful vibration generated during the operation of ship power equipment will not only produce noise,affect the physical and mental health of crew members,but also lead to structural damage.For military ships,the vibration and noise generated by the operation of power equipment will also reduce the concealment of ships and increase the possibility of being attacked.Vibration isolation is an effective method to control vibration transmission,mainly including passive vibration isolation and active vibration isolation.Passive vibration isolation system is easy to install and does not need external energy.At present,passive vibration isolation has been widely used in the vibration control of marine machinery and equipment,and has achieved good control effect in the medium and high frequency band.However,due to the fixed parameters,the passive vibration isolation device can not adapt to the changes of the system,which may lead to the deterioration of the control effect,and it is difficult to effectively isolate vibration in the low frequency band.Therefore,active vibration isolation technology with the help of external force source appears.Active vibration isolation technology can effectively control low-frequency vibration,improve the safety and concealment of ships,and improve the working environment.This paper takes the double-layer vibration isolation system as the controlled object to study the active vibration control.On the one hand,an improved SVSFx LMS algorithm is designed for active control;On the other hand,the optimal layout of actuators in double-layer vibration isolation system is studied,and the optimal layout number and location of actuators are determined through active control joint simulation.The specific research contents of this paper are as follows:Firstly,the isolation effect of single and double-layer vibration isolation system is analyzed,and the shortcomings of passive vibration isolation system and the necessity of introducing active control technology are pointed out.Parametric modeling is carried out through command flow in APDL to study the optimal layout of actuators.The model of double-layer vibration isolation system is established in Adams software for joint simulation of active control.Then,the basic principle of Fx LMS adaptive algorithm is analyzed,and an improved SVSFx LMS adaptive algorithm is proposed based on the fixed step Fx LMS algorithm and the existing variable step algorithm.The comparative simulation of several algorithms proves the superiority of the improved algorithm in this paper.Then,taking the double-layer vibration isolation system as the controlled object,the optimal layout of its actuators is studied.Taking the comprehensive controllability optimization criterion as the evaluation standard of optimization simulation and genetic algorithm as the optimization algorithm,this paper calculates the optimal layout scheme of actuators when 4,6 and 8 actuators are arranged on the middle platform of the double-layer vibration isolation system.Finally,based on the Adams double-layer vibration isolation system model,taking the SVSFx LMS-NEW algorithm designed in this paper as the control algorithm,the active control joint simulation of the optimal layout schemes of 4,6and 8 channels is carried out respectively.By studying the control effects of the three groups of schemes under 20 Hz / 80 Hz central excitation and eccentric excitation respectively,the optimal layout number and location of actuators of the double-layer vibration isolation system are determined.