A dual-microphone-based active noise reduction method for trackside acoustic signals of train bearings

An active noise reduction and acoustic signal technology, applied in the direction of frequency response correction, etc., can solve the problems that the denoising effect needs to be further improved, the array signal processing algorithm is complex, and it is difficult to eliminate in-band noise, etc., so as to reduce the number of microphones and simplify the processing algorithm , The effect of eliminating in-band noise

CN110740407BActive Publication Date: 2020-11-24ANHUI UNIVERSITY
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
Publication Date
2020-11-24

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Abstract

The invention discloses a dual-microphone-based active noise reduction method for train bearing railside acoustic signals. Two microphones are placed beside the railroad track. On the same vertical line, the dual microphones simultaneously collect the sound from the wheel-set bearings, wheel-rail contact noise and background noise. Then, the signals collected by the reference microphones are demodulated and remodulated, so that the Doppler distortion rules of the noise signals collected by the two microphones are consistent. Finally, the least mean square algorithm is used to complete the active noise reduction of the acoustic signal of the train bearing trackside. The invention adopts dual microphones to realize the denoising of the acoustic signal of the train bearing rail, has the advantages of using less microphones, can eliminate in-band noise, and self-adaptive active noise reduction, and can effectively improve the signal-to-noise ratio of the acoustic signal of the train bearing rail . The invention can be used for acoustic fault diagnosis of train bearing rail edge.
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Description

Technical field

[0001] The invention belongs to the field of high-speed train bearing fault diagnosis, and in particular relates to a dual-microphone-based active noise reduction method for train bearing railside acoustic signals. Background technique

[0002] As an important transportation tool worldwide, the safe operation of trains is directly related to the safety of property and the lives of passengers. As a key component of the train, real-time monitoring and diagnosis of its health status is particularly important for wheel-set bearings. The trackside acoustic diagnosis technology uses microphones placed on both sides of the rail to collect the sound signals emitted by the bearing when the train passes, and obtains the bearing health information through signal processing. However, since the sound signal emitted by the bearing in the early stage of failure is relatively weak, it is often submerged by noise, which brings difficulties to accurate diagnosis. In the rail-side ...

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Embodiment Construction

[0030] In order to make the above-mentioned features and advantages of the present invention more obvious, the following describes the present invention in detail with reference to the accompanying drawings and embodiments:

[0031] Step (1-1). In this article, simulate the actual situation and construct the simulation signal of bearing and wheel-rail contact noise, such as Figure 4 (a) and Figure 4 (c) Shown. The two microphones synchronously collect the sound signal and noise signal from the bearing of the wheelset. The signals collected by the two microphones are like Figure 4 (b) and Figure 4 (d) Shown.

[0032] Step (1-2): Perform inverse modulation signal processing on the signal ref(t) collected by the reference microphone in the time domain and frequency domain to obtain the signal ref_correct(t), such as Figure 5 As shown in (a), then the signal ref_correct(t) is re-modulated to obtain the signal ref_modulate(t), as Figure 5 As shown in (b), the Doppler distortion law...