自适应结构振动主动控制的最佳效果实现

Realization of Optimal Results in Adaptive Active Vibration Control

推导了在自适应结构振动控制中不同控制目标函数下,次级力源的最优强度以及所能获得的最佳振动和声幅射抵消比计算公式,通过理论和计算分析讨论了次级振源和误差传感器的选择和布放规律。研究结果表明,在次级振源和误差传感器的位置选择中,结构模态振型间的相位关系与幅度同样重要;当采用传声器在声场中提取误差信号时,控制效果对误差传声器位置的敏感程度较低。采用以 TMS320C25为中央处理单元的自适应主动控制系统进行了实验研究,获得了满意的抵消效果,理论与实验结果吻合良好。

The vibration of sound radiation from a rectangular plate controlled by direct force inputs are theoretically analyzed,and the formulae for optimizing secondary source strengthes and calculating the ob- tainable sound and vibration attenuation levels are derived using various cost functions.On the basis of this,the optimization of arrangement of secondary sources and error sensors is discussed.It is shown that, when the positions of secondary sources and error sensors are optimized,besides the amplitudes of struc- tural vibration modes,the phase differences of them must be considered as well.When accelerometers are chosen as error sensors,the number of them should meet that of the secondary sources,while when error signals are picked up in the sound field,fewer microphones can provide a satisfactory attenuation of radiat- ed sound,and their positions are less critical.An experiment was carried out using an adaptive active con- troller consisted of TMS320C25 and Filter-X LMS algorithm,and validation of the theory was proved.