Main Content

Time-Synchronous Averaging

Use time-synchronous averaging (TSA) when you are working with data from rotating machinery.

With rotating machinery, a single rotation period encapsulates the full gamut of machinery component interaction. Averaging over uniform rotation angles or complete rotations, rather than averaging over more arbitrary time segments, rejects any noise, disturbance, or periodic signal content that is not coherent with the rotation. This rotation-based averaging is calledtime-synchronous averaging, orTSA.

  • Tacho Information— Rotation rate, specified as one of the following:

    • Constant rotation speed (RPM)— Use constant RPM when your rotation rate is fixed both in time and across all ensemble members.

    • Tacho signal— Use a tacho signal when you have a tachometer that transmits pulses at specific angular points in the rotation. Your tacho signal must have the same length as your data signal.

    • Compute nominal speed (RPM)— Compute the nominal rotation speed for each individual machine when processing the tacho signal. Select this option if the rotation speeds of your machines vary across the ensemble and you plan on filtering the TSA signal (see过滤器TSA信号). The app stores the computed rotation speeds in a condition variable with the suffixrpm.

      For an example of performing TSA processing with varying nominal wheel speeds, seeIsolate a Shaft Fault Using Diagnostic Feature Designer

  • Interpolation method— Select the interpolation to use when computing the TSA signal. For information on the interpolation methods and the algorithms for using them, seetsa.

  • Pulses per rotation— Number of tachometer pulses in each rotation. Set this parameter only when using a tacho signal.

  • Number of rotations— Typically, a TSA signal averages over a single rotation. Increase the number of rotations when you want to improve frequency resolution for follow-on filtering of the TSA signal.

The software stores the results of the computation in a new variable. The new variable name includes the source signal name with the suffixtsa.

Additional Information

For more information on: