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A signal processing method for analyzing combustion noise based on multiple injection conditions

A technology of combustion noise and multiple injections, which is applied in the field of signal processing, can solve problems that cannot affect the integration, achieve accurate analysis, and realize the effect of precise segmentation

Active Publication Date: 2018-12-11
HARBIN ENG UNIV
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Problems solved by technology

But despite this, it is still impossible to integrate the impact of each injection on combustion noise, so as to evaluate combustion noise more effectively

Method used

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  • A signal processing method for analyzing combustion noise based on multiple injection conditions
  • A signal processing method for analyzing combustion noise based on multiple injection conditions
  • A signal processing method for analyzing combustion noise based on multiple injection conditions

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Embodiment Construction

[0022] The following examples describe the present invention in more detail.

[0023] combine figure 1 , the concrete steps of the present invention are as follows:

[0024] Step 1: According to the attached figure 2 The three-layer stationary wavelet packet decomposition is performed on the cylinder pressure signal x(t) under the condition of secondary injection of the diesel engine, and the stationary wavelet packet coefficient of the kth sub-band of the i-th layer is

[0025]

[0026] where f i,k (τ) is the stationary wavelet packet filter of the kth sub-band in the i-th layer, and its length L i =(2 i-1 )(L-1)+1. The stationary wavelet packet filter bank consists of wavelet filter h i (τ) and scale filter g i (τ), both of which are obtained by zero-interpolation at intervals of the previous filter

[0027]

[0028]

[0029] The signal component of the kth sub-band in layer i is

[0030]

[0031] At layer i, the decomposed signal is reconstructed

[0...

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Abstract

The present invention provides a signal processing method for analyzing combustion noise based on multiple injection conditions. The method includes: 1, decomposing a cylinder pressure signal of a diesel engine under the condition of secondary injection by a three-layer stationary wavelet packet decomposition, and reconstructing the wavelet packet sub-signal; 2, dividing that wavelet packet sub-signals in each frequency band into a pre-spray influence part and a main spray influence part according to the pre-main spray time in the time domain; 3, extracting the pre-main injection influence part divided in the step 2, calculating the stationary wavelet packet energy of each sub-signal pre-main injection stage, and taking the stationary wavelet packet energy as the combustion noise energy for comparative analysis. The method separates the influence of the pre-main injection in the time domain, also realizes the accurate division of the frequency spectrum by the translation invariance ofthe stationary wavelet packet, and refines the influence of the pre-main injection on the combustion noise from the time-frequency domain. The method has the advantages of direct and accurate analysisof the effect of pre-main injection on combustion noise, and can provide a parameter optimization method for multi-injection to reduce combustion noise of a diesel engine.

Description

technical field [0001] The invention relates to a signal processing method, in particular to a signal processing method for analyzing the influence of pre-main injection on combustion noise under the condition of multiple injections of a diesel engine. Background technique [0002] In response to the current stringent emission regulations, many diesel engine combustion technologies have been proposed and applied one after another. Among them, the diesel engine PPCI-LTC (partial premixed compression ignition-low temperature combustion) mode combined with the control strategy of pre-injection can not only achieve the goal of low emission and high efficiency, but also shorten the ignition delay and reduce combustion noise. Under this condition, selecting the appropriate pre-injection parameters can effectively reduce combustion noise, so the method of evaluating the influence of different injection parameters on combustion noise is very important. [0003] By processing the cy...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G06K9/00G06F17/14
CPCG06F17/148G06F2218/16G06F2218/06G06F2218/08
Inventor 刘龙陈曦明杜敬涛
Owner HARBIN ENG UNIV
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