【摘要】 首先介绍了两种国内外比较有代表性的小波阈值改进方法,并在传统软、硬阈值函数的基础上提出了一种新的改进阈值函数,通过对小波系数的阈值处理,使得去噪后的信号在过分平滑与边缘振荡现象之间达到合理的平衡。对一段压气机台架实验数据的仿真分析表明:该方法在去噪的同时减少了有用信息的损失,在信噪比增益和最小均方差误差方面的性能指标要优于传统软、硬阈值法,同时在3种改进阈值函数方法中具有最佳的去噪性能。更多还原

【Abstract】 Two typical methods for modifying wavelet threshold functions were introduced,and basing on traditional soft and hard threshold functions,a new modified threshold function was proposed. Through the threshold processing of wavelet coefficients,the signals de-noised reached the balance between excessive smoothness and edge oscillations. Simulating experiment data from a compressor bench shows that this method can reduce the loss of useful information while de-noising the signals,and the performance index is superior to traditional soft and hard in SNR gain and in the minimum mean square error,and it has the best de-noising performance of three modified threshold methods.更多还原