MTS Series 793 - Manual (Page 76)

MTS Series 793 Tuning and Calibration
How to Manually Tune the Control Loop
Tuning Procedures 76
Tuning the Force Control Mode
To complete this task, you will make sure the force tuning values established in
your station parameter set are appropriate for the test you are about to run. To do
this, you will:
• Create and apply a simple tuning program.
• Evaluate the current force tuning values by comparing command and
feedback signals.
Once established, displacement tuning values are unlikely to require adjustment;
in contrast, optimal force tuning values are a function of your specimen’s
compliance and often change over time, or even from test-to-test. You should
also tune force whenever you make any change to the force train (such as
changing fixtures).
Prerequisites Be sure the following conditions are present before you begin tuning the force
control mode:
Standalone Controller and Automated Controllers:
• Hydraulic pressure is off.
• The specimen is not installed
Automated Controllers only:
• You have created a station configuration file.
• You have created a station parameter set.
Procedure
The following is a step-by-step tuning procedure for a force control mode. It is a
basic procedure that should work for most applications. However, you should
consider it a guideline. The background information presented in this chapter
should help you modify the following procedure for your specific system.