Sound signal noise reduction method and system of foreign matter in electric energy meter

Abstract

The invention discloses a sound signal noise reduction method and system of foreign matter in an electric energy meter on the basis of short-time energy, multi-scale entropy and EMD. The method includes the steps that noise data generated by shaking of the foreign matter in the electric energy meter is collected; foreign matter sound signal data is extracted through short-time energy positioning;the extracted foreign matter sound signal data is subjected to empirical mode decomposition (EMD), and the multi-scale entropy of each stage of intrinsic mode function (IMF) component obtained throughEMD is calculated; the multi-scale entropy of the IMF components is subjected to noise reduction and filtering to obtain sound signals, obtained after noise reduction and filtering, of the foreign matter in the electric energy meter. The method has the advantages that short-time energy positioning can be used for data extraction to increase the processing speed; the sound signals of the foreign matter in the electric energy meter are processed through multi-scale entropy and empirical mode decomposition, which is a self-adaptive process, and the defect that traditional spectrum subtraction noise reduction estimation is not accurate is overcome; meanwhile, introduction of new noise is avoided to the maximum degree, and the foreign matter in the electric energy meter can be accurately detected.

Description

technical field [0001] The invention relates to the technical field of electric energy meters, in particular to a method and system for reducing noise of foreign matter sound signals in electric energy meters based on short-term energy, multi-scale entropy and EMD. Background technique [0002] The existing automatic detection device for foreign matter in the electric energy meter simulates the manual method, designs the structure of the shaker meter, and realizes the shaker meter and sound collection through electrical control. Process the collected sound to judge whether there are foreign objects. Due to the large background noise in the external environment, for example: the sound of the motor belt, the noise generated by the work of the operator and the operation of the machine, etc. These interfering noises may affect the final detection results. [0003] The sound signal of foreign objects in the electric energy meter is a nonlinear and non-stationary signal. At pres...

AI Technical Summary

Problems solved by technology

Although the principle of spectral subtraction is simple and easy to implement in real time, it is too rough, and the estimation of noise is easy to be inaccurate, so it is not an adaptive process; secondly, the positioning of the collected sound data is not accurate enough, and the data is redundant; finally, it is easy to introduce new noise

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