基于动力吸振器的空间桁架多自由度振动抑制

为实现对大型空间柔性桁架结构的振动控制,提出了一种基于动力吸振器的桁架多自由度自适应振动控制方法.首先阐述了采用多个动力吸振器实现桁架多自由度振动抑制的SISO(Single Input Single Output)控制策略,然后仿真验证了单吸振器系统对多频扰动的自适应抑制能力.其中控制算法为多频ADC算法,该算法无需知道结构的精确模型,即能通过自适应控制律实现对多频振动的抑制.仿真结果显示,相对被动吸振器,各频率分量抑制效果分别提高了62.38 dB和42.51 dB.最后实验验证了多动力吸振器对三棱柱桁架多自由度振动的抑制效果,实验结果显示,动力吸振器对单频振动的各自由度抑制效果分别为95.13%,93.59%和95.01%,对多频振动的各自由度抑制效果分别为94.26%,91.55%和93.42%.

Multi-degree-of-freedom vibration suppression of space trusses based on multiple dynamic vibration absorbers

To implement vibration control of large and light flexible space trusses (LLFST), an adaptive method of suppressing MDOF vibrations of trusses via multiple dynamic vibration absorbers (DVA) was presented. Firstly the single-input and single-output (SISO) control strategy for MDOF vibration control with multiple DVAs was interpreted. Secondly the adaptive control effectiveness of a single DVA subjected to multi-frequency vibrations was proved by simulations. The adaptive algorithm is multi-frequency adaptive disturbance canceller (ADC) which is utilized for suppressing the multi-frequency vibration adaptively without the knowledge of the precise model. The simulation results show that the vibrational attenuations of each frequency component are 62.38 dB and 42.51 dB respectively, compared with passive DVA. Finally, an experiment on the three DOF vibration control of a triangular truss via multiple DVAs was conducted. The experimental results show that the single-frequency vibrational attenuations of each DOF are 95.13%, 93.59% and 95.01%, respectively,and the multi-frequency vibrational attenuations of each DOF are 94.26%, 91.55% and 93.42%, respectively.