关键词: 振动与波, 差分振子, 时间历程, Hilbert变换, 故障诊断

Abstract:

Abstract: Single differential oscillator can only detect a certain frequency component in the periodic signal detection. In order to determine the interval of side band of the signal under strong noise background, it is feasible to test frequencies of the multiple differential oscillator array one by one. But it will undoubtedly bring great amount of calculation which is uneconomical. Hilbert transform can be used to obtain the low frequency component of the signal in the modulation signal envelope analysis. But, if the low frequency component contains strong noise, the following traditional spectrum analysis will be failure, which is undesired. To solve the problem, the time history of differential oscillator can be used to test the gained envelope signal that consists of strong noise. So, in this paper, a new weak modulation signal detection method, based on time history of differential oscillator, is proposed. First, Hilbert transform is used in the envelope demodulation to gain the envelope component of the signal. Then ,do envelope demodulation test on the gained component which contains strong noise through the method of differential oscillator time history. The method had been successfully applied in the early fan fault detection.