脉冲切削力激励的铣削系统工作模态辨识方法

铣削系统模态参数决定了机床的在役可靠性和加工质量. 加工过程中铣削系统随主轴转速和接触条件的 改变而发生重构，其模态参数相较经典实验模态法获取的静态下的结果发生显著改变. 脉冲切削力在关心频带 内能产生具有平坦频谱的激励信号，可利用工作模态分析方法的多参考点最小二乘复指数法仅由该激励下的 振动响应辨识切削系统模态参数，实现了加工过程中对切削系统工作模态参数的动态辨识. 将此方法应用于铣 削加工中心切削系统工作模态参数辨识并设计了切削实验. 实验结果表明，所述方法估计的工作模态参数相较 锤击试验法更接近系统真实动力学行为，使铣削系统的实时监测、主动维护、稳定性动态预测成为可能.
Modalparametersofmillingsystemcontributegreatlytothereliabilityofthemachinetoolintheserviceand machiningquality.Duringtheoperation,theywilldifferfromtheresultsofstaticexperimentalmodalanalysis,because themillingsystemwillbereconstructedwiththechangeofspindlespeedandcontactcondition.Impulsecuttingexcita? tionhasflatspectrumintheinterestingbandwidth.Withthisexcitationandoperationalmodalanalysistheory,poly-ref? erenceleastsquarecomplexexponentialmethodisimplementedtoestimateoperationalmodalparametersonlythrough theresponsesignal.Thendynamicalestimationofmillingsystemoperationalmodalparametersduringoperationisreal? ized.AcuttingexperimentisdesignedandconductedinaCNCmachinetool.Itturnsoutthatoperationalmodalparame? tersestimatedbythepresentedmethodaremoreaccuratethantheonesbyimpacttesting,andmoreclosetotherealdy? namicsduringoperation.Itwillenablethereal-timemonitoringmillingsystemandactivemaintenance,aswellasdy? namicpredictingchatterstability.