基于HFHA LCD的液压泵振动信号降噪方法研究

针对局部特征尺度分解LCD(Local Characteristic Scale Decomposition)降噪方法处理非平稳机械振动信号存在的缺点，提出一种基于高频谐波加入 局部特征尺度分解HFHA LCD(High Frequency Harmonic Added Local Characteristic Scale Decomposition)的方法来自适应实现液压泵非平稳振动信号降噪。该方法首先向原信号中加入高频谐波，然后对混合信号进行LCD分解，再以各内禀尺度分量ISC（Intrinsic Scale Component）与原信号的相关系数为准则选取有用ISC分量，最后以有用ISC分量重构原信号，达到降噪目的。仿真信号分析结果表明，HFHA LCD较LCD可以有效抑制模态混叠现象，提高分解精度，HFHA LCD降噪方法的效果也明显优于LCD降噪方法，基于HFHA LCD的液压泵振动信号降噪结果验证了该方法的有效性。

De noising Method Based on HFHA LCD for Vibration Signals of Hydraulic Pump

Aimed at defects of method based on LCD de noising in processing non stationary mechinery vibration signals, a method based on HFHA LCD, which adaptively eliminates noise, is presented for hydraulic pump’s non stationary vibration signals. Firstly, high frequency harmonic is added to original vibration signals; secondly, mixed signals is decomposed by LCD; thirdly, ISC’s Correlation with original vibration signals is treated as standard to sift useful ISC. Finally, original vibration signals is reformed by useful ISC to reach purpose of de noising. Analysis of simulation signals indicate that,compared to LCD, HFHA LCD can restrain mode mixing effectively and improve accuracy of LCD decomposition.At the same time, ability of de noising by HFHA LCD is also superior to LCD. Result of de noising prove the advantage of Method for Vibration Signals of Hydraulic Pump Based on HFHA LCD.