基于降阶模型的水下结构振动主动控制仿真及实验研究

基于降阶模型对水下结构振动的主动控制进行了仿真及实验研究,并取得了较好的抑制振动的效果。基于结构在可压缩流体加载下的无阻尼实模态矩阵建立了水下结构的降阶模型,由于维数的降低,进而能够设计出相对简化的主动控制系统,减少传感器和作动器的数量。通过线性二次型最优控制和结构主动变刚度控制两种方法对水下结构振动进行了主动控制仿真,均使结构振动有所下降。仿真结果显示线性二次型最优控制能够降低结构振动的峰值,而结构主动变刚度控制能够将结构的固有频率按照需要进行改变。还通过水下平板振动主动控制模型实验,验证了主动控制技术对水下结构的减振效果。

Active vibration control simulation and experiment studies of underwater structures based on a reduced order model

In order to effectively suppress vibration of an underwater structure, its active vibration control simulation and experiment studies were implemented based on a reduced order model. The compressible fluid-loaded undamped modal matrix was used to build the reduced order model of the underwater structure. Due to dimension number’s reduction, a simplified vibration active control system was designed to decrease the number of sensors and actuators. Active control of underwater structural vibration of a plate was simulated with the linear quadratic（LQ）control method and the variable stiffness control method, respectively. The simulation results showed that the plate’s vibration amplitude is quite well controlled with the LQ control method, while the natural frequencies of the plate can be changed according to requirements with the variable stiffness control method; based on the reduced order model, the active control is relatively easy to implement and the experimental results verifies the vibration reduction effects of active control technique on underwater structures.