MTS Systems FlexTest SE Service Information

About Tuning
Model 493.02 Controller Service
Tuning
209
Random function
generator
When tuning AIC compensator configurations, it is necessary to
generate random functions to properly simulate typical test conditions.
Random functions employ a pre-emphasis filter to make the
convergence rate constant over all frequencies. The random function
options include:
• Random - 1/F
2
• Random - 1/F
• Random - Flat (none)
• Random - F
• Random - F
2
Frequency A low-frequency waveform is adequate for most testing. Tests at higher
frequencies cause a frequency shift that cannot be completely
corrected with the PIDF adjustments.
• Do your initial tuning at a low frequency, and then fine tune at the
highest frequency in your test program. Common values are
1–2 Hz.
• Servo adjustments that do not improve performance at high
frequencies generally indicate that the servovalve is running at
100% capacity or the HPS is running at 100% capacity.
This characteristic can easily be seen when tuning with a sine
waveform. The feedback waveform appears to be more like a ramp
waveform when running at 100% capacity.
Amplitude A system tuned at a low amplitude may become unstable at high
amplitudes. Tuning should be accomplished under conditions similar
to the anticipated usage.
• Use a moderate amplitude (5% to 10% full scale) for initial tuning.
• Be sure the maximum velocity of the tuning command is 10% to
50% of the maximum velocity of the system.
• Increase the amplitude for fine tuning.
• You may find it helpful to check tuning over a variety of
amplitudes by creating a test that cycles once at each of the target
amplitudes.

MTS Systems FlexTest SE Specifications

General

Brand	MTS Systems
Model	FlexTest SE
Category	Controller
Language	English