振动吸收器三自由度结构非并置式振动控制研究报告.ppt

*冲击测试采用吸收器测试系统–冲击和扫描测试预调整和安装吸收器fs2=f2或fs3=f3*物体（一）的冲击响应FFT频谱.吸收器预设参数不同情况下的冲击响应当fs2=f2时，物体（一）的冲击响应FFT频谱当fs3=f3时，物体（一）的冲击响应FFT频谱吸收器电流和固有频率之间的关系*吸收器的频率预调整到16.569Hz.吸收器的频率预调整到29.256Hz.吸收器电流变化范围ApplycurrentI=0~2.3AI=2.3~-2.3AI=-2.3A~2.3AStep=0.1A通过扫描实验确认频率响应特性*.与激振频率相对的稳态加速度的大小fs2=f2fs3=f3扫描电流I=-2.3A~2.3A通过平均值建立关系*和fa的关系平均曲线调和平均曲线调和子系统:

从电流I得出固有频率fsiKsMs子系统矩阵30.Basedonwhatwehaveknown,wedevelopedthreewaystocompletethenon-collocatedvibrationcontrol.(Upper)First,weusefindtheexcitingfrequencyandoutputthenecessarycurrentaccordingtothefrequencytocontrolthevibration.(Middle)Second,weconsidertheexcitingfrequencyandatthesametimeconsidermeansquaredvalueoftheaccelerometersignalstocontrolthevibration.(Lower)Wejustconsiderthemeansquaredvalueofaccelerationsignal.Let’sseehowthethreemethodswork.31.ThefirstmethodisFFT-basedmethod.TheExcitationsystemgeneratesasinusoidalsignal.Thesignalissenttoadigitaltoanalogchannelandpoweramplifiertodrivetheshaker.TheaccelerationsignalmeasuredbyanaccelerometerissampledatananalogtodigitalchannelADC.FFToutputsfrequencyoftheresponse.Thenthecomputercalculatestheoutputcurrentaccordingtotheinputfrequency.ThedigitalsignalisthentransferredtoAnalogcurrentandamplifiedtothecoiloftheEMVA.32.ThesecondmethodisFFT-basedmethodplusfineadjustment.TheonlydifferenceisthatastheTheExcitationSubsystemgeneratesasinusoidalsignal.Thesignalissenttoadigitaltoanalogchannelandpoweramplifiertodrivetheshaker.TheaccelerationsignalmeasuredbyanaccelerometerissampledatananalogtodigitalchannelADC.FFToutputsfrequencyoftheresponse.Thenthecomputercalculatesanoutputcurrentaccordingtotheinputfrequency.Ifthemeansquaredvalueofaccelerationsignali