Instant frequency estimation method based on edge detection

A technology of instantaneous frequency and edge detection, which can be used in measurement devices, testing of mechanical parts, testing of machine/structural parts, etc.

Inactive Publication Date: 2017-02-01
NANJING UNIV OF INFORMATION SCI & TECH
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Problems solved by technology

For example, the adjacent order analysis method of orthogonal compensation matrix combined with discrete Fourier is greatly affected by the change of order amplitude and the degree of interference between adjacent orders.
However, the number of source signals required for independent component analysis to separate signals must not be less than the number of independent components, which makes the adjacent order analysis method of independent component analysis combined with peak search have limitations in actual use.

Method used

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  • Instant frequency estimation method based on edge detection
  • Instant frequency estimation method based on edge detection
  • Instant frequency estimation method based on edge detection

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Embodiment Construction

[0021] The present invention will be further described below in conjunction with the accompanying drawings. The following examples are only used to illustrate the technical solution of the present invention more clearly, but not to limit the protection scope of the present invention.

[0022] In this embodiment, a signal is first simulated. Sampling frequency f s =5012HZ, sampling time 5s. The reference frequency varies linearly from 20Hz to 100Hz.

[0023] The frequency at the nth sampling moment is expressed as f(n)=20+80n / N. The angular velocity at the nth sampling moment is expressed as w(n)=2π f(n), is the phase angle rotated at the nth sampling moment, and Δt is the sampling time interval.

[0024] The amplitude of the first-order frequency signal jumps at 500, as shown in formula (3):

[0025]

[0026] The amplitude of the second-order frequency signal changes sinusoidally, as shown in formula (4):

[0027] B(n)=0.8+sin(2πn / N) (4)

[0028] The amplitude of t...

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Abstract

The invention discloses an instant frequency estimation method based on edge detection. Through the use of the time-frequency spectrum of the short-time Fourier transform, one can effectively feel the frequency variation of the signal components and the boundary technology of effectively extracting the picture pixel changes in SOBEL operator edge detection. When the two are combined, the frequency of some order component of the signal can be effectively extracted. According to the invention, the edge detection technology in picture processing technology is employed. Under proper parameters, it is possible to rapidly and accurately determine the frequency edges. In comparison to other methods, the method is advantageous both in terms of the complexity and the calculation amount.

Description

technical field [0001] The invention relates to an instantaneous frequency estimation method based on edge detection, and belongs to the technical field of mechanical equipment fault diagnosis. Background technique [0002] Rotating machinery has become an indispensable part of industrial production. In order to ensure the normal operation of rotating machinery, it is particularly important to perform status detection and fault diagnosis on rotating machinery. Vibration signals in the acceleration and deceleration stages of rotating machinery contain rich state information, and it is easier to find system defects that are usually difficult to find when studying this stage. Therefore, being able to effectively extract the fault features at this stage is an important link in the fault diagnosis of rotating machinery and is of great significance to the normal operation of rotating machinery. [0003] In order to better understand the fault information of rotating machinery, va...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01M13/00G01H17/00
CPCG01M13/00G01H17/00
Inventor 王丽华谢阳阳张永宏赵晓平陶润喆
Owner NANJING UNIV OF INFORMATION SCI & TECH
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