中文摘要：

螺旋桨脉动力是引起轴系—壳体振动的主要因素。基于频域模型,研究轴—壳系统耦合振动特性及参数影响,从原理上分析在推进轴系上施加控制力来抑制耦合系统振动的控制方法,并讨论基于自适应前馈控制策略的主动控制方案。采用自适应对消及归一化最小均方算法,在轴上施加纵向控制力,实时抵消脉动推力,降低轴系纵向振动,由此抑制由于轴系振动所引起的壳体振动。仿真结果表明：控制力施加位置对控制效果影响很小,不同轴承刚度对控制力大小的需求不同,刚度较小时误差收敛速度较慢,刚度达到一定程度以后收敛速度不变。通过轴—壳体试验系统对原理分析进行验证,结果也表明推力轴承刚度对轴系纵振频率的影响,所提出的控制方法能够有效地抑制壳体振动。

英文摘要：

Propeller thrust fluctuation is the major factor that induces vibration in a shaft-hull system.Based on the frequency domain model of the shaft-hull system,dynamic characteristics of this system are discussed and the mechanism of suppressing the system vibration by applying control force on the shaft is analyzed.An adaptive feedforward control strategy is proposed in terms of the mechanism.Numerical results demonstrate that control forces applied on the shaft are able to cancel the fluctuating thrust force to reduce the longitudinal vibration of the shaft and the hull.The influence of parameters on the coupled system is also discussed and the results show that location of the control forces have little effect on the control performance,different thrust stiffness results in different control force level,and the convergence rate of the control error changes with the thrust stiffness,but it will keep unchanged when the stiffness is large enough.An experimental model is established to verify numerical analyses.Stiffness of the thrust bearing changes the longitudinal vibration frequency of the shaft,and the proposed active control strategy is able to suppress the shaft and hull vibration effectively.