电磁轴承支承的船舶推进轴系纵向振动变刚度控制方法研究

Variable Stiffness Control Method of Longitudinal Vibration of Ship Propeller-Shafting Supported by Active Magnetic Bearings

关键词:  推进轴系  电磁轴承  变刚度控制  纵向振动  动力学  减振降噪

Key words:  Propeller-shafting  Active magnetic bearing  Variable stiffness control  Longitudinal vibration  Dynamics  Vibration and noise reduction

摘要:

船舶推进轴系纵向非定常激励激发壳体结构振动和辐射噪声，严重影响航行隐蔽性。针对这一问题，结合电磁轴承支承特性主动可控优势，首先提出了一种采用电磁轴承支承的推进轴系结构，然后推导了含推力电磁轴承结构及控制参数的轴系纵向振动频率方程，最后提出了一种基于纵向激励频率的变刚度控制方法。仿真结果表明，在推力电磁轴承可变等效刚度范围内，增大控制器比例系数，可有效提高轴系一阶纵向固有频率，对高阶纵向固有频率影响不大；轴系在不同转速下工作时可以选用不同比例系数，实时调节轴系纵向振动传递特性，有效减小纵向激励向壳体传递。

Abstract:

Longitudinal unsteady excitation of ship propeller-shafting excites shell structure vibration and radiated noise， which seriously affects navigation concealment. Aiming at this problem， combined with the advantages of active controllability of active magnetic bearing （AMB） support characteristics， firstly， a propulsion shafting structure supported by AMBs was proposed. Then， the longitudinal vibration frequency equation of the shafting including the thrust AMB structure and control parameters was deduced. Finally， a variable stiffness control method based on longitudinal excitation frequency was proposed. The simulation results show that within the variable equivalent stiffness range of the thrust AMB， increasing the proportional coefficient of the controller can effectively increase the first-order longitudinal natural frequency of the shafting， and has little effect on the high-order longitudinal natural frequency. Different proportional coefficients could be selected when the shafting works at different speeds， which can adjust the longitudinal vibration transmission characteristics of the shafting in real time and effectively reduce the transmission of longitudinal excitation to the shell.