Signal Processing Concepts and Engineering Insights. 


Explore signal processing concepts, algorithm comparisons, and practical engineering insights.
Topics include FFT vs STFT, FRF analysis, filtering techniques, and other signal processing methods used in real engineering workflows. 

Signal FundamentalsWhat Is a Peak in Signal Analysis? (And Why It Matters)

What Is a Peak in Signal Analysis? (And Why It Matters)

In signal analysis, a peak represents a point where the signal reaches a local maximum.

Peaks often indicate important events or features in a signal.

What Is a Peak in Signal Analysis

What Is a Peak?

A peak is a point where the signal is higher than its neighboring values.


Mathematical Idea


Mathematical Idea


Intuition

“The highest point in a small region”


Peak Finding result with markers

Peak Finding result


Types of Peak values

1. Local Peak value

  • Small peaks within neighborhood values


2. Global Peak value

  • Highest value in entire signal


3. Sharp vs Broad Peak values

  • Sharp → sudden event
  • Broad → gradual change


Why Peak values Matter

Peaks help identify.

Machine Faults

  • abnormal vibration spikes


Biomedical Signals

  • ECG → heartbeat detection


Audio Signals

  • loud events


Peaks = key events in signals


Peak Detection Methods

Simple Method

  • Compare neighboring values


Threshold Method

  • Detect peaks above a certain value


Advanced Methods

  • Smoothing + detection
  • Statistical methods (IQR, Z-score) → Outlier detection


MALMIJAL Application
  • Peak Detection function
  • IQR (Inter-Quartile Range) outlier detection

detected peaks highlighted

Detected peaks highlighted (refer to Samples/peaks, outliers.mmj)


outlier detection

Outlier detection using IQR (refer to Samples/peaks, outliers.mmj)


Peak Parameters

Important features

  • Peak height → amplitude
  • Peak position → time
  • Peak width → duration


Challenges in Peak Detection

  • Noise can create false peaks
  • Overlapping peak values
  • Weak signals


Solution

  • Filtering (MA, EMA, FIR, IIR)
  • Envelope(amplitude) detection


MALMIJAL Workflow

Peak Analysis
  1. Load a signal
  2. Apply filtering (optional)
  3. Run peak detection
  4. Extract peak features


Load signal (t_y.out)Load a signal (t_y.out) and display

 

Run Peak Finding

Peak Finding by clicking Ok


Extract peak features

Extract peak features


Key Takeaways

  • Peak = local maximum
  • Represents important events
  • Used in many real-world applications
  • Detection requires careful tuning


Conclusions

A peak represents a local maximum in a signal and serves as a key indicator of important events or features.

  • Peaks provide valuable insights in many real-world applications, such as machine fault detection, biomedical signals, and audio analysis.
  • They can be detected using various methods, including simple comparison, thresholding, and statistical approaches like Z-score, IQR, depending on the situation.
  • However, noise and overlapping signals can cause false detections, so proper filtering and preprocessing are essential.

In summary,
peak detection is a fundamental technique for identifying significant events in signals, and accurate results depend on careful tuning and preprocessing.


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