Unlock instant, AI-driven research and patent intelligence for your innovation.

Zero phase filter design method based on EMD (Empirical Mode Decomposition)

A filter design, zero-phase technology, used in instruments, calculations, computer parts, etc., can solve problems such as abnormality and imperfect judgment conditions

Active Publication Date: 2018-11-13
NANJING INST OF TECH
View PDF5 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Some experts and scholars have put forward corresponding IMF judgment conditions, but these judgment conditions are not perfect, resulting in some abnormal effects in the screening process

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Zero phase filter design method based on EMD (Empirical Mode Decomposition)
  • Zero phase filter design method based on EMD (Empirical Mode Decomposition)
  • Zero phase filter design method based on EMD (Empirical Mode Decomposition)

Examples

Experimental program
Comparison scheme
Effect test

example

[0066] figure 2 is a non-stationary signal X(t), image 3 Yes figure 2 Spectrum diagram, the frequency range of filtering is now required: 85K~185KHz, f n =85Hz, f N =185Hz, such as Figure 4 , 5 As shown, through the above steps, zero-phase filtering is realized.

[0067] The first step: determine the frequency resolution of the used EMD, according to the method of the present invention, determine the used EMD is 0.85.

[0068] Take x(t)=X(t), f n =85Hz,f N =185Hz, since 185×0.85>85, take f=185Hz.

[0069] Take the maximum magnitude value A max ( Figure 4 2), the minimum amplitude value A min ( Figure 4 in -2).

[0070] The second step: use step 2 to construct the filtered harmonic signal: y(t)=20×cos(2π×185×t).

[0071] third step:

[0072] (1) Construct h(t)=x(t)+y(t).

[0073] (2) Use EMD to decompose h(t) to obtain IMF1 and the remaining amount r(t).

[0074] (3)k(t)=IMF1-y(t)

[0075] (4) take j i (t)=k(t), since

[0076] f N ×0.85 i =185×0.85 i ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention discloses a zero phase filter design method based on EMD (Empirical Mode Decomposition). A decomposition effect measurement index index is determined, then a frequency decomposition ratebeta of EMD which meets the decomposition effect measurement index index is determined according to a decomposition effect segmentation line, and a filtering signal is constructed by the frequency decomposition rate beta, so that the zero phase filter design method can ensure accurate instantaneous phase information of a non-stationary signal and implements zero phase filtering of the non-stationary signal. The method which is disclosed by the invention and uses a ratio of a mean line to a screened object as an IMF (Intrisical Mode Function) judgment condition, when the ratio is smaller thana constant value, considers that a mean allowance does not need to be removed and a qualified IMF is obtained, so that signal decomposition is stable in the screening process and an abnormal conditioncannot be generated.

Description

technical field [0001] The invention belongs to the technical field of digital signal processing, and in particular relates to a zero-phase filter design method based on EMD (Empirical modedecomposition, empirical mode decomposition). Background technique [0002] Most of the signals in engineering are non-stationary signals, and digital filters are an indispensable part of signal processing in engineering data acquisition. Digital filter processing is analyzed from the perspective of system response, which is to multiply the modulus of the system frequency response on the model characteristic, and the phase characteristic is to add the phase of the system frequency response to the input phase. Therefore, the phase of the system frequency response is added to the signal, which changes the relative phase relationship between each component. Even if the modulus of the system frequency response is constant for each component of the signal, the signal has a great change in the t...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): G06K9/00
CPCG06F2218/02
Inventor 胥保春吴京秋汪木兰
Owner NANJING INST OF TECH