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

Aircraft multi-frequency vibration signal recognition method based on wavelet packet and STFT

A technology of vibration signal and identification method, which is applied in the direction of instruments, measuring ultrasonic/sonic/infrasonic waves, complex mathematical operations, etc., to achieve the effects of narrowing the frequency analysis range, improving frequency identification accuracy, and improving accuracy

Inactive Publication Date: 2018-10-02
NANJING UNIV OF SCI & TECH
View PDF5 Cites 4 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

But there is no relevant description in the prior art

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
  • Aircraft multi-frequency vibration signal recognition method based on wavelet packet and STFT
  • Aircraft multi-frequency vibration signal recognition method based on wavelet packet and STFT
  • Aircraft multi-frequency vibration signal recognition method based on wavelet packet and STFT

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0041] A series of complex vibration signals are produced in a certain link of the flight of the aircraft, and the sampling time is 0.005 seconds. The complex vibration signals are sampled within a period of time to obtain 2500 sampling signal data, and the identification method of the present invention is used to process the sampling signals in MATLAB The simulation analysis is carried out on the simulation platform.

[0042] Step 1. Use the wavelet function to perform wavelet packet decomposition on the complex vibration signal of the aircraft:

[0043] After using the sym7 wavelet function to decompose the complex vibration signal of the aircraft into three layers, the schematic diagram of the three-layer decomposition of the wavelet packet is as follows figure 2 As shown in Table 1, the corresponding frequency ranges of the nodes in the third layer of the wavelet packet tree are shown in Table 1.

[0044] Table 1. Corresponding frequency range of the third layer of the w...

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 proposes an aircraft multi-frequency vibration signal recognition method based on a wavelet packet and STFT, and the method comprises the steps: employing a wavelet function for the wavelet packet decomposition of a complex vibration signal of an aircraft; calculating the energy of each band after decomposition: calculating the energy of each band after decomposition and the percentage of the energy of each band to the total energy; reconstructing a frequency band with the maximum energy, extracting the frequency band with the maximum energy, and reconstructing the wavelet packetcoefficient in the frequency band into a signal component; carrying out the STFT analysis of the frequency band on which the frequency of the vibration signal of the aircraft is concentrated througha window function, and recognizing the main frequency in the vibration signal of the aircraft. The method provided by the invention can recognize the frequency in the complex vibration signal of the aircraft, so as to improve the stability and reliability of the aircraft.

Description

technical field [0001] The invention belongs to the field of complex vibration signal detection, in particular to an identification method for aircraft multi-frequency vibration signals based on wavelet packets and STFT. Background technique [0002] During the flight of the aircraft, the attitude of the aircraft is affected by interference factors such as complex airflow and the impact of the lateral overload of the aircraft, resulting in the generation of non-stationary vibration signals. Moreover, since new types of aircraft need to have the characteristics of high speed, high maneuverability, and long life, they will suffer from more severe and complex vibrations. The non-stationarity of the vibration signal brings great difficulties to the aircraft safety test and subsequent analysis. Therefore, the multi-frequency identification of this kind of non-stationary vibration signal can provide a reliable basis for the design of vibration damping filter, the research of high...

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): G01H17/00G06F17/14
CPCG01H17/00G06F17/14G06F17/148
Inventor 丁萌姚伟吴利平吴少文郭毓朱锐虞文杰郭健吴益飞
Owner NANJING UNIV OF SCI & TECH