PULSE Reflex Advanced Order Analysis Type 8705

When combined with PULSE Reflex Basic Order Analysis Type 8704, this option provides a comprehensive set of order analysis tools for understanding the vibration behavior of rotating machinery.

Uses

• Leakage-free, high accuracy order analysis
• Deals with fast speed sweeps and high order numbers
• Aircraft or automotive engine vibration
• Determination of critical speeds and resonances
• Root cause analysis of tonal sound quality issues
• Phased order analysis – e.g., as input to SPC
• Vehicle NVH benchmarking

Features

• Tracked re-sampling FFT analysis
• Order analysis based on order domain spectra
• Tachometer dropout/spurious pulse correction
• Tachometer smoothing
• Tachometer pulse train synthesis from RPM profile
• Autotracker - RPM profile and tachometer synthesis from response signals

Order analysis is integrated into the same workflow as all the other analysis functions (CPB, FFT, and overall analysis) in PULSE Reflex Core. In fact all that is necessary to analyse with tracked resampling is to tick the “Tracked Sampling” box in the property pane of the required FFT element – see FFT vs. Time example below. When the box is unchecked, the element becomes a standard FFT vs. Time analyzer.





The complete analysis workflow is illustrated in the figure below, in which a recording has been imported to the Project Browser; is loaded into the Time Editor for listening and simultaneous viewing of frequency and order content; is then analysed to show the tracked orders versus RPM, and finally the results are stored back into the Project Browser.




Note: The spectrogram inside the Time Editor is synchronised with the time display so that, when a signal is played, the time cursors move together across the screen, making it easy to relate audible sounds to visible features in the spectrogram display. This stage in the process enables decisions to be made on optimal parameters for analyzing the data in the process chain. Note that the spectrogram feature requires PULSE Reflex Advanced Processing Type 8703.

The final step - automatically generating a report containing all the analysis results - is only one one mouse click away.

Useful features that help prepare the input data for analysis are: 

• Tachometer pulse train synthesis from an RPM profile; e.g., from CAN data or voltage-proportional-to-speed data
• Tachometer repair:
       - Spline fit for smoothing of profiles
       - Hermite spline for fixing wild points in a profile, usually caused by double or missing pulse anomalies
• An Auto-tracker task for generating an RPM profile from FFT vs. Time output of non-tachometer signals; e.g., acceleration or sound pressure data. When combined with tachometer pulse train synthesis, this enables RPM-related analysis of data without a tachometer measurement.