Algorithms | latest | crest-factor

Crest factor

The crest factor is defined as the ratio of the peak amplitude to the RMS of a signal. It can be intepreted as a measure for the impulsiveness of a signal.

$CrestFactor=\frac{max|x|}{\sqrt{\frac{1}{N}\sum _{i=0}^{N-1}x[i{]}^2}}$

Applications

• Fault detection in bearings and gear boxes

References

• https://en.wikipedia.org/wiki/Crest_factor
• Caesarendra, W., & Tjahjowidodo, T. (2017). A Review of Feature Extraction Methods in Vibration-Based Condition Monitoring and Its Application for Degradation Trend Estimation of Low-Speed Slew Bearing. Machines, 5(4), 21. https://doi.org/10.3390/machines5040021
• Abouel-seoud, S. A. (2018). Fault detection enhancement in wind turbine planetary gearbox via stationary vibration waveform data. Journal of Low Frequency Noise Vibration and Active Control. https://doi.org/10.1177/1461348417725950

Code

INFO

The following snippet is written in a generic and unoptimized manner. The code aims to be comprehensible to programmers familiar with various programming languages and may not represent the most efficient or idiomatic Python practices. Please refer to implementations for optimized implementations in different programming languages.

code.py

import numpy as np


def crest_factor(signal: np.ndarray) -> float:
    return np.max(np.abs(signal)) / np.sqrt(np.mean(signal**2))

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