机械振动微弱慢频变信号的混沌振子检测

机械振动微弱信号的检测与识别有利于早期故障的检测与诊断。用Duffing混沌振子检测微弱振动信号具有明显的优势。提出了用混沌振子检测慢变频微弱振动信号的方法。在给出Duffing混沌振子对微弱信号检测的基本原理后，根据慢频变信号的特征，对信号进行了周期离散，提出了对暂态信号进行时域延拓的方法，分析了可行性。提出了幅频联调方法，设计了检测原理，并给出了实现步骤。结合所提出的两种方法，对带噪声的频变微弱振动信号进行了检测分析。仿真结果和实际采集信号分析结果支持了所提出方法的适用性。

Detection by Chaotic Oscillator on Weak Signal Slowly Frequency Change of Mechanical Vibration

The detection and identification on weak signal of mechanical vibration were advantaged for forepart fault diagnosis. It has obvious superiority to detect the weak signals by Duffing chaotic oscillator. The detection by chaotic oscillator on weak signal slowly frequency change of mechanical vibration was first advanced. The weak signal slowly frequency change was dispersed according to its frequency change characteristics after the fundamental of weak signal detection by Duffing oscillator was introduced. A backward expand method for transient signal in time domain was advanced. The feasibility of this method was analyzed. For the detection of signals by Duffing oscillator, a combined adjustment method for the amplitude with frequency was presented. Its detection principle was designed and its realization steps were presented. Combining two methods, it is detected and analyzed that the weak signal slowly frequency change accompanied by noise. The applicability of the methods is verified by simulation analysis and real rotational signal analysis.