Matching pursuit method for coupling modulation signal separation of gearbox vibration

Abstract

Vibration of faulty gearbox usually consists of smooth modulation and impulse modulation components. The successful application of signal sparse representation has demonstrated its effectiveness of feature extraction. However, it mainly concentrates in the impulse components but ignores the smooth modulation components, and the designed dictionary is lack of clear physical meaning, which brings poor universality. A novel method based on matching pursuit is proposed for coupling modulation signal separation of gearbox vibration. The designed smooth modulation dictionary based on the amplitude modulation atom fuses the operation and structure characteristics of gearbox, as well as the designed pulse modulation dictionary based on the impulse response function of single-degree-freedom system. So the dictionaries have clear physical meaning and wide universality. Simulation and experiment test validates the effectiveness of the proposed method, even if under the condition of strong noise and fully coupled modulation signals. The approach of amplitude recovery can significantly reduce the influence of over-matching.