基于調(diào)制隨機(jī)共振的轉(zhuǎn)子故障早期檢測(cè)

噪聲是影響旋轉(zhuǎn)機(jī)械早期故障檢測(cè)的主要因素。只有抑制噪聲增強(qiáng)信號(hào)、提高信噪比，才能從噪聲中提取故障特征信息，為故障診斷特別是早期故障檢測(cè)提供可靠的依據(jù)。文中根據(jù)非線性雙穩(wěn)系統(tǒng)在噪聲和弱周期信號(hào)作用下的周期響應(yīng)特性，將調(diào)制技術(shù)與隨機(jī)共振原理相結(jié)合，提出了調(diào)制隨機(jī)共振方法，實(shí)現(xiàn)了在較寬的頻率范圍內(nèi)從強(qiáng)噪聲中檢測(cè)微弱周期信號(hào)。理論分析、數(shù)值仿真和實(shí)驗(yàn)結(jié)果表明，對(duì)信號(hào)進(jìn)行調(diào)制產(chǎn)生的差頻分量可形成低頻信號(hào)，該低頻信號(hào)通過(guò)雙穩(wěn)系統(tǒng)易產(chǎn)生隨機(jī)共振，從而使隨機(jī)共振發(fā)生在具有優(yōu)良頻率特性的低頻區(qū)，能使微弱的故障信號(hào)特征突出、明顯而易于捕捉。該方法靈活、可靠，在轉(zhuǎn)子系統(tǒng)早期故障檢測(cè)方面的應(yīng)用是可行的。

Noise is the main factor influencing incipient rotor machine failure detection. Only when the noise is suppressed and SNR is improved, the failure characteristic information can be picked up from noise supplying the reliable basis for failure detection especially the incipient failure detection. The modulated stochastic resonance method is proposed according to the period response characteristics in nonlinear bistable system caused by noise and weak period signal. The weak periodic signals can be distinguished from strong noise in broaden frequency range with this method. The theoretical analysis, numerical simulation and experiment results manifest that differential frequency component generated by signal modulation can form low frequency signal. The stochastic resonance is easily generated when the low frequency signal acts on the bistable system. The frequency of stochastic resonance is on low frequency range making the characteristics of weak fault signal obviously and easily to capture. The method is flexible, reliable and effective in application of the incipient fault detection in rotor system.