1. Engineering Department ,Ordnance Engineering College, Shijiazhuang, 050003;2. Automobile Engineering Department , Academy of Military Transportation, Tianjin, 300161
Abstract： For the non-stationary and color noise characteristics of accelerating vibration signal from diesel engine , a method based on computed order tracking (COT) and bi-spectrum is proposed. The unstable signal is re-sampled at constant angular interval and the stabilized signal is obtained at the order area, then to analyze by bi-spectrum method. The simulation shows that the order bi-spectrum analysis is superior to the conventional bi-spectrum. To utilize the information from order bi-spectrum results fully , the novel concept—bi-spectrum characteristic order plane is put forward . Different working conditions of engine can be reflected by comparing the accumulated energy within order plane. Experimental results indicate that this method can extract feature of accelerating vibration signal effectively.
2013, Vol. 32 
