恰当的制动片形状设计,可抑制盘式制动器的高频尖叫。为分析发生噪声的原因和抑制方法,对一个存在13 k Hz尖叫的制动器,建立了一个截止到27 k Hz、含300自由度的模型。该模型用复特征值分析、子结构模态构成分析、能量馈入分析等方法,...恰当的制动片形状设计,可抑制盘式制动器的高频尖叫。为分析发生噪声的原因和抑制方法,对一个存在13 k Hz尖叫的制动器,建立了一个截止到27 k Hz、含300自由度的模型。该模型用复特征值分析、子结构模态构成分析、能量馈入分析等方法,分析了对制动片开槽、倒角及其组合等4种形状修改模式降噪的机制。结果表明:双开槽的制动片修改,对抑制噪声效果不明显;但对两端做倒角的制动片修改,效果明显,其特征值实部与原设计相比,下降50%,这一结果与试验定性一致。这表明:制动片倒角导致各阶模态振型的改变及其叠加,因此,降低了对噪声模态的能量馈入。展开更多
Purpose–The electromechanical brake system is leading the latest development trend in railway braking technology.The tolerance stack-up generated during the assembly and production process catalyzes the slight geomet...Purpose–The electromechanical brake system is leading the latest development trend in railway braking technology.The tolerance stack-up generated during the assembly and production process catalyzes the slight geometric dimensioning and tolerancing between the motor stator and rotor inside the electromechanical cylinder.The tolerance leads to imprecise brake control,so it is necessary to diagnose the fault of the motor in the fully assembled electromechanical brake system.This paper aims to present improved variational mode decomposition(VMD)algorithm,which endeavors to elucidate and push the boundaries of mechanical synchronicity problems within the realm of the electromechanical brake system.Design/methodology/approach–The VMD algorithm plays a pivotal role in the preliminary phase,employing mode decomposition techniques to decompose the motor speed signals.Afterward,the error energy algorithm precision is utilized to extract abnormal features,leveraging the practical intrinsic mode functions,eliminating extraneous noise and enhancing the signal’s fidelity.This refined signal then becomes the basis for fault analysis.In the analytical step,the cepstrum is employed to calculate the formant and envelope of the reconstructed signal.By scrutinizing the formant and envelope,the fault point within the electromechanical brake system is precisely identified,contributing to a sophisticated and accurate fault diagnosis.Findings–This paper innovatively uses the VMD algorithm for the modal decomposition of electromechanical brake(EMB)motor speed signals and combines it with the error energy algorithm to achieve abnormal feature extraction.The signal is reconstructed according to the effective intrinsic mode functions(IMFS)component of removing noise,and the formant and envelope are calculated by cepstrum to locate the fault point.Experiments show that the empirical mode decomposition(EMD)algorithm can effectively decompose the original speed signal.After feature extraction,signal enhancement and fault identificatio展开更多
文摘恰当的制动片形状设计,可抑制盘式制动器的高频尖叫。为分析发生噪声的原因和抑制方法,对一个存在13 k Hz尖叫的制动器,建立了一个截止到27 k Hz、含300自由度的模型。该模型用复特征值分析、子结构模态构成分析、能量馈入分析等方法,分析了对制动片开槽、倒角及其组合等4种形状修改模式降噪的机制。结果表明:双开槽的制动片修改,对抑制噪声效果不明显;但对两端做倒角的制动片修改,效果明显,其特征值实部与原设计相比,下降50%,这一结果与试验定性一致。这表明:制动片倒角导致各阶模态振型的改变及其叠加,因此,降低了对噪声模态的能量馈入。
基金funded by the Science Foundation of China Academy of Railway Science,grant number 2020YJ175.
文摘Purpose–The electromechanical brake system is leading the latest development trend in railway braking technology.The tolerance stack-up generated during the assembly and production process catalyzes the slight geometric dimensioning and tolerancing between the motor stator and rotor inside the electromechanical cylinder.The tolerance leads to imprecise brake control,so it is necessary to diagnose the fault of the motor in the fully assembled electromechanical brake system.This paper aims to present improved variational mode decomposition(VMD)algorithm,which endeavors to elucidate and push the boundaries of mechanical synchronicity problems within the realm of the electromechanical brake system.Design/methodology/approach–The VMD algorithm plays a pivotal role in the preliminary phase,employing mode decomposition techniques to decompose the motor speed signals.Afterward,the error energy algorithm precision is utilized to extract abnormal features,leveraging the practical intrinsic mode functions,eliminating extraneous noise and enhancing the signal’s fidelity.This refined signal then becomes the basis for fault analysis.In the analytical step,the cepstrum is employed to calculate the formant and envelope of the reconstructed signal.By scrutinizing the formant and envelope,the fault point within the electromechanical brake system is precisely identified,contributing to a sophisticated and accurate fault diagnosis.Findings–This paper innovatively uses the VMD algorithm for the modal decomposition of electromechanical brake(EMB)motor speed signals and combines it with the error energy algorithm to achieve abnormal feature extraction.The signal is reconstructed according to the effective intrinsic mode functions(IMFS)component of removing noise,and the formant and envelope are calculated by cepstrum to locate the fault point.Experiments show that the empirical mode decomposition(EMD)algorithm can effectively decompose the original speed signal.After feature extraction,signal enhancement and fault identificatio
