加速度信号小波降噪的改进算法

目的:人体运动产生的加速度信号在采集过程中经常会混入各种噪声和干扰,这给后续的研究带来了困难,因此对采集得到的加速度信号进行降噪处理是后期运动功能评价的前提和基础。方法:为了更好地分离有用信号和噪声干扰,根据小波阈值降噪的原理和小波高频系数方差的分布,针对小波分解层数的确定、阈值估计和阈值函数的选择3个方面提出了改进的算法。结论:实验结果证明,改进的算法能够很好地抑制噪声对加速度信号的干扰,提高了评估的准确度,达到了预计的效果。

Wavelet De-noising Algorithm of Acceleration Signal

Acceleration signal of human body motion often mixed with a variety of noise and interference, which makes the subsequent research more difficult. So the noise reduction is the premise and foundation of later motor function evaluation. In order to separate the useful signal and noise better, according to the principle of wavelet threshold de-noising and variance distribution of the high frequency wavelet coefficients, the algorithm is proposed regarding the three aspects including the decomposition level determination, the threshold estimation and the selection of threshold function. Experimental results show that, the improved algorithm can effectively reduce the noise, improve the accuracy of the assessment, and achieve the expected results.