针对消噪过程中信号细节难以保留的问题,采用了一种基于小波变换的空域相关消噪方法。通过运用信号小波分解后与噪声的小波系数随尺度变化规律不同的特性,实现了信号与噪声的分离,同时给出了表面肌电信号噪声能量阈值的估计算法。实验结果表明,该消噪处理方法不仅能有效地去除肌电信号中的噪声,而且可以较好地保留肌电信号的边缘特征,为下肢表面肌电信号特征的提取创造了良好的条件。
Aiming at the problem of difficult to retain the details of signal in the process of de-noising, a de-noise method of the spatial correlation filtering(SCF) based on wavelet transformation was introduced. Through using the fact that signal and noise after wavelet decomposition have different characteristics with the wavelet scale, the separation of signal and noise was realized, and the arithmetic of estimating noise-energy threshold of superficial electromyography(SEMG) was proposed. The experimental results indicate that the method of the signal de-noising can be more effective in the de-noising SEMG noise, and it can reserve the fringe eharacter of SEMG, which offers good condition for withdrawing the characters of SEMG of the lower limb.