基于HHT的超声电机噪声源分析  

Analysis of noise source in ultrasonic motor based on HHT

作　　者：向馗[1] 郭吉丰[1] 蒋静坪[1] 

机构地区：[1]浙江大学电气工程学院,浙江杭州310027

出　　处：《振动工程学报》2005年第2期200-203,共4页Journal of Vibration Engineering

摘　　要：对超声电机的噪声信号做希尔伯特-黄变换(HHT),发现噪声中从始至终都含有10kHz左右的成分。在分析了电机运动机理后,以转子为对象建立碰撞摩擦模型,从系统的加速度响应中,同样分解出10kHz左右的成分。说明系统运动非线性产生的分数次谐波,是诱发噪声的直接原因。对定子作有限元分析,得到定子的一阶模态频率为10.74kHz,与噪声频率非常接近,表明分数次谐波激发了定子共振,为噪声输出提供了能量源。为了降低噪声,可以考虑降低定子、转子的碰撞强度或改进定子、转子的结构。The unorderly noise signal of the ultrasonic motor is decomposed into Hilbert spectrum with two main frequency bands by HHT. One band centralizes at 20 kHz which origin is pumping frequency, and the other centralizes at 10 kHz which emit the noise audible to the human ear. The ultrasonic motor works through the impact and rubbing between the stator and the rotor. From this point, the dynamic equations of the rotor are established based on the rigid-body dynamics principles and solved by the fourth-order Runge-Kutta method. The result shows that nonlinearity of the system induces the fractional harmonic which roots in the noise. The finite element analysis of the stator indicates that the energy of the noise comes from the resonance of the stator at 10.74 kHz. For reducing the noise, weakening the impact or remodeling the stator and the rotor can be useful, and the former is better.

关 键 词：超声电机 噪声 希尔伯特-黄变换 碰撞摩擦模型 加速度响应 

分 类 号：TB533.1[理学—物理] TM3[理学—声学]