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How ahc works – MTS Series 793 Controller User Manual

Page 63

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About Compensators

MTS Series 793 Controller Overview

Operation Concepts

63

Adaptive Harmonic Cancellation is typically used when programming with pure
sinewave commands or sine sweeps in acceleration control. Also, ALC is
typically used in high-frequency MAST systems for ground vehicle testing.

How AHC Works

Because cancellation occurs at the system output by means of a signal at the
system input, the phase response of the system must be known. The control
system model, or “model” for short, is an adaptive finite-impulse-response (FIR)
filter, and provides the phase response. Before you turn cancellation on, you must
train the system phase response by commanding the system with a sine sweep or
a random signal over the frequency range of operation.