针对轨边声学轴承信号有用特征微弱、易被强噪声掩盖的问题,设计实现了一种将最小熵解卷积与改进局域均值分解相结合的方法,达到信号降噪与故障诊断目的。利用三次Hermite插值改善LMD并提高LMD分解精度。将采集到的强噪信号进行MED降噪...针对轨边声学轴承信号有用特征微弱、易被强噪声掩盖的问题,设计实现了一种将最小熵解卷积与改进局域均值分解相结合的方法,达到信号降噪与故障诊断目的。利用三次Hermite插值改善LMD并提高LMD分解精度。将采集到的强噪信号进行MED降噪,再利用改进LMD算法进行分解,使多分量信号分解成单分量信号,并计算各分量的峭度值,挑选出峭度值最大的分量,最后利用包络谱分析,提取滚动轴承的故障特征。计算信号的峰值信噪比(PSNR,Peak Signal to Noise Ratio),将其作为降噪指标,体现方法的降噪性能。实验结果表明,设计的方法应用于轴承故障诊断,能将信号信噪比提高5.13 dB,能精准定位并提取轴承缺陷位置和信号特征,具有较好降噪和信息分辨能力。展开更多
Hermite interpolation is a very important tool in approximation theory and nu- merical analysis, and provides a popular method for modeling in the area of computer aided geometric design. However, the classical Hermit...Hermite interpolation is a very important tool in approximation theory and nu- merical analysis, and provides a popular method for modeling in the area of computer aided geometric design. However, the classical Hermite interpolant is unique for a prescribed data set, and hence lacks freedom for the choice of an interpolating curve, which is a crucial requirement in design environment. Even though there is a rather well developed fractal theory for Hermite interpolation that offers a large flexibility in the choice of interpolants, it also has the short- coming that the functions that can be well approximated are highly restricted to the class of self-affine functions. The primary objective of this paper is to suggest a gl-cubic Hermite in- terpolation scheme using a fractal methodology, namely, the coalescence hidden variable fractal interpolation, which works equally well for the approximation of a self-affine and non-self-affine data generating functions. The uniform error bound for the proposed fractal interpolant is established to demonstrate that the convergence properties are similar to that of the classical Hermite interpolant. For the Hermite interpolation problem, if the derivative values are not actually prescribed at the knots, then we assign these values so that the interpolant gains global G2-continuity. Consequently, the procedure culminates with the construction of cubic spline coalescence hidden variable fractal interpolants. Thus, the present article also provides an al- ternative to the construction of cubic spline coalescence hidden variable fractal interpolation functions through moments proposed by Chand and Kapoor [Fractals, 15（1） （2007）, pp. 41-53].展开更多
文摘针对轨边声学轴承信号有用特征微弱、易被强噪声掩盖的问题,设计实现了一种将最小熵解卷积与改进局域均值分解相结合的方法,达到信号降噪与故障诊断目的。利用三次Hermite插值改善LMD并提高LMD分解精度。将采集到的强噪信号进行MED降噪,再利用改进LMD算法进行分解,使多分量信号分解成单分量信号,并计算各分量的峭度值,挑选出峭度值最大的分量,最后利用包络谱分析,提取滚动轴承的故障特征。计算信号的峰值信噪比(PSNR,Peak Signal to Noise Ratio),将其作为降噪指标,体现方法的降噪性能。实验结果表明,设计的方法应用于轴承故障诊断,能将信号信噪比提高5.13 dB,能精准定位并提取轴承缺陷位置和信号特征,具有较好降噪和信息分辨能力。
基金partially supported by the CSIR India(Grant No.09/084(0531)/2010-EMR-I)the SERC,DST India(Project No.SR/S4/MS:694/10)
文摘Hermite interpolation is a very important tool in approximation theory and nu- merical analysis, and provides a popular method for modeling in the area of computer aided geometric design. However, the classical Hermite interpolant is unique for a prescribed data set, and hence lacks freedom for the choice of an interpolating curve, which is a crucial requirement in design environment. Even though there is a rather well developed fractal theory for Hermite interpolation that offers a large flexibility in the choice of interpolants, it also has the short- coming that the functions that can be well approximated are highly restricted to the class of self-affine functions. The primary objective of this paper is to suggest a gl-cubic Hermite in- terpolation scheme using a fractal methodology, namely, the coalescence hidden variable fractal interpolation, which works equally well for the approximation of a self-affine and non-self-affine data generating functions. The uniform error bound for the proposed fractal interpolant is established to demonstrate that the convergence properties are similar to that of the classical Hermite interpolant. For the Hermite interpolation problem, if the derivative values are not actually prescribed at the knots, then we assign these values so that the interpolant gains global G2-continuity. Consequently, the procedure culminates with the construction of cubic spline coalescence hidden variable fractal interpolants. Thus, the present article also provides an al- ternative to the construction of cubic spline coalescence hidden variable fractal interpolation functions through moments proposed by Chand and Kapoor [Fractals, 15（1） （2007）, pp. 41-53].
