考虑作动器输出约束的圆柱壳基础主被动联合隔振系统

Passive-active vibration isolation system mounted in a circular cylindrical shell with actuator output constraints

针对圆柱壳内动力装置的减振降噪问题,建立由动力装置振源、隔振支承及圆柱壳基础组成的自适应前馈控制主被动混合隔振系统模型。在频域分析中引入剪断算法及泄漏算法以计及作动器的输出约束。考虑被动弹性支承的分布参数特性,以输入到圆柱壳基础的总功率最小、径向力最小及径向速度最小为控制策略,运用子结构导纳法推导总体系统的动态特性传递矩阵方程。研究表明:两种算法均能收到良好的主动控制力约束效果,并可有效抑制最小化径向力及最小化径向速度策略下的"功率循环"现象发生。采用径向速度最小化策略会改变壳体基础的边界条件配置,使得功率流谱中基础模态峰值右移。外扰引起的被动隔振器纵向及弯曲谐振使得高频域系统功率流谱中个别峰值峭立突出,成为诱发高频声辐射的关键模态,应严格限制。旨在为下一步的试验工作及实际应用提供理论指导。

To deal with the vibra-acoustic problem about a power machinery mounted in a cylinder shell,an adaptive feed forward passive-active vibration isolation model consisting of complex excitations,isolators,and a circular cylindrical shell foundation was established.In frequency domain analysis,the output clipping algorithm and leaky algorithm were introduced to consider the output constraint of actuators.Considering distributed parametric features of passive-elastic supports,using the control strategies of minimizing the total power input into the shell foundation,the radial forces and the radial velcities,the coupled vibration transfer matrix equation of the overall system was derived with the substructure mobility approach.Numerical simulations showed that the two algorithms can both receive good active control constraint effects,and can both effectively restrain the phenomenon of power circulation;using the radial velocities minimization strategy can change the boundary condition of the shell foundation and lead to shell modal peaks moving to higher frequencies;considering the distributed parametric characteristic of passive isolators,the system power spectrum has some prominent peaks which are the principal modes to induce acoustic radiation at high frequencies.The study results provided a theoretical guidance for further tests and practical applications.