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

A design method of zero-phase filter based on emd

A filter design and design method technology, applied in the direction of instruments, calculations, computer components, etc., can solve problems such as abnormalities and imperfect judgment conditions

Active Publication Date: 2021-06-11
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
  • A design method of zero-phase filter based on emd
  • A design method of zero-phase filter based on emd
  • A design method of zero-phase filter based on emd

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] Step 1: Determine the frequency resolution of the EMD used. According to the method of the present invention, the EMD used is determined to be 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 an EMD-based zero-phase filter design method. By determining the decomposition effect measurement index index, and then determining the frequency resolution rate β of the EMD satisfying the decomposition effect measurement index index according to the decomposition effect dividing line, the frequency resolution rate β Construct filter signal, make the present invention can guarantee the accurate instantaneous phase information of non-stationary signal, realize the zero-phase filtering of non-stationary signal, the present invention adopts the method for IMF judgment condition as the ratio between mean line and screened object, when this ratio When it is less than a constant value, it is considered that it is no longer necessary to remove the mean margin, and a qualified IMF is obtained, so that the signal decomposition is stable in the screening process and no abnormal situation will occur.

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 Patents(China)
IPC IPC(8): G06K9/00
CPCG06F2218/02
Inventor 胥保春吴京秋汪木兰
Owner NANJING INST OF TECH