煤矿开采
煤礦開採
매광개채
COAL MINING TECHNOLOGY
2015年
4期
9-13,35
,共6页
HHT法%煤冲击破坏%低频电磁信号%EMD分解%分离式霍普金森杆
HHT法%煤遲擊破壞%低頻電磁信號%EMD分解%分離式霍普金森桿
HHT법%매충격파배%저빈전자신호%EMD분해%분리식곽보금삼간
HHT method%impact failure of coal%low-frequency electromagnetic signal%EMD decomposition%split Hopkinson pres-sure bar
针对煤冲击破坏低频磁场信号的高噪声、非线性、非平稳等特征，将HHT时频分析方法引入到低频磁场信号的时频分析中，介绍了HHT时频分析方法及原理，利用该方法对煤冲击破坏低频磁场信号进行去噪分析和时频处理。研究结果表明： EMD分解重构不但可对信号进行去噪处理，还能很好地刻画出低频电磁信号的非线性、非平稳性及脉冲特性；低频磁场信号的频谱图可清晰表示出能量随时间和频率的动态变化，从频谱图中得出，低频磁场信号的优势频率在0～40 Hz之间，其持续时间小于2 s；与傅里叶变换和小波分析相比， HHT分析方法的时间、频率分辨率较高，有完全的时频局部性，可很好地描述电磁信号的时变特征，是电磁信号时频分析的有效方法。
針對煤遲擊破壞低頻磁場信號的高譟聲、非線性、非平穩等特徵，將HHT時頻分析方法引入到低頻磁場信號的時頻分析中，介紹瞭HHT時頻分析方法及原理，利用該方法對煤遲擊破壞低頻磁場信號進行去譟分析和時頻處理。研究結果錶明： EMD分解重構不但可對信號進行去譟處理，還能很好地刻畫齣低頻電磁信號的非線性、非平穩性及脈遲特性；低頻磁場信號的頻譜圖可清晰錶示齣能量隨時間和頻率的動態變化，從頻譜圖中得齣，低頻磁場信號的優勢頻率在0～40 Hz之間，其持續時間小于2 s；與傅裏葉變換和小波分析相比， HHT分析方法的時間、頻率分辨率較高，有完全的時頻跼部性，可很好地描述電磁信號的時變特徵，是電磁信號時頻分析的有效方法。
침대매충격파배저빈자장신호적고조성、비선성、비평은등특정，장HHT시빈분석방법인입도저빈자장신호적시빈분석중，개소료HHT시빈분석방법급원리，이용해방법대매충격파배저빈자장신호진행거조분석화시빈처리。연구결과표명： EMD분해중구불단가대신호진행거조처리，환능흔호지각화출저빈전자신호적비선성、비평은성급맥충특성；저빈자장신호적빈보도가청석표시출능량수시간화빈솔적동태변화，종빈보도중득출，저빈자장신호적우세빈솔재0～40 Hz지간，기지속시간소우2 s；여부리협변환화소파분석상비， HHT분석방법적시간、빈솔분변솔교고，유완전적시빈국부성，가흔호지묘술전자신호적시변특정，시전자신호시빈분석적유효방법。
For the high-noise, nonlinear and non-stationary characteristics of low-frequency signal in impact failure process of coal, introducing HHT time-frequency analysis method into low-frequency signal analysis, denoising and time-frequency disposing of low-fre-quency signal was finished with this method.Results showed that EMD decomposition and reconstitution could not only denoise signal, but also describe well nonlinear, non-stationary and pulsing characteristics of low-frequency electromagnetic signal.Spectrogram of low-frequency magnetic signal could clearly show dynamic variation of energy with time and frequency.From spectrogram, dominant fre-quency of low-frequency magnetic signal was within 0~40Hz and its duration was less than 2s.Compared with Fourier transform and wavelet analysis, HHT method has higher time and frequency resolution, whole time-frequency localization and could well describe time-varying characteristic of electromagnetic signal, which is effective method for time-frequency analysis of electromagnetic signal.
