基于EMD和能量算子的模态参数识别在行星齿轮箱中的应用  

Modal parameter identification based on empirical mode decomposition and energy operator for planetary gearboxes

作　　者：李康强 冯志鹏[1] LI Kangqiang;FENG Zhipeng(School of Mechanical Engineering,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]北京科技大学机械工程学院,北京100083

出　　处：《振动与冲击》2018年第8期1-8,共8页Journal of Vibration and Shock

基　　金：国家自然科学基金(11272047;51475038) ;教育部新世纪优秀人才支持计划(NCET-12-0775)

摘　　要：针对行星齿轮箱模态试验下多自由度、低频、密频的模态参数识别问题,提出一种将经验模式分解(Empirical Mode Decomposition,EMD)与能量算子(Energy Operator,EO)相结合的模态参数识别方法。为了定阶模态和满足能量算子对单分量的要求,采用EMD方法将振动信号分解成多个固有模式函数(Intrinsic Mode Function,IMF)。对各个IMF利用高阶能量算子估算频率,计算各IMF与原信号的相关性并根据频率判断阶次及去除虚假分量。由于阻尼比本质就是反映能量衰减,而能量算子能够追踪系统能量,结合二者提出半周期能量算子法估算模态阻尼比。分析了仿真信号和模态试验信号,并与传统方法进行对比分析,实验结果表明,该方法能有效提取行星齿轮箱各阶次的模态参数,验证了方法的有效性与可行性。In order to identify modal parameters for a planetary gearbox which has property of multi-degree of freedom,low frequency,and dense frequency,a new approach was introduced in conjunction with the empirical mode decomposition(EMD)and energy operator(EO).A vibration signal was decomposed into several intrinsic mode functions(IMFs)via the EMD method to determine the mode order and to satisfy the requirement of the EO.Then we estimate the modal frequencies of each IMF via the higher order energy operator.According to the correlation between IMFs and the original signal,we could distinguish the mode order by the size of frequency.In essence,the damping ratio reflects the energy attenuation.Meanwhile,the energy operator can track the system energy.Based on the aforementioned two theories,we put forward a half cycle energy operator(HCEO)method to estimate damping ratio.By comparing conventional methods,the proposed method was illustrated and verified by simulations and experiments.The results show that the proposed method is effective to extract modal parameters of a planetary gearbox.

关 键 词：模态频率 结构阻尼比 能量算子 行星齿轮箱 

分 类 号：TH113.1[机械工程—机械设计及理论] TH132.425