MTS Material Test Systems User Manual

Page 54

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Description

Item

Program

3

Transducer feedback

4

If the gain is set too high, unstable system operation can result. This instability may cause specimen damage.
Consequently, gain should be set as high as possible while maintaining stable system operation.

Rate (D)

The rate adjustment improves the servo control loop dynamic stability by reducing the overshoot at higher
proportional gain settings. It reduces the system bandwidth, closing the servovalve in anticipation of achieving
the commanded position through the rate of change in feedback. The following figure shows the effect of
adding rate to a transducer feedback signal that has already been adjusted for gain.

Table 11: Rate adjustment

Description

Item

Response time

1

Overshoot

2

Program

3

Transducer feedback

4

Reset (I) (DC conditioners only)

The reset adjustment increases system accuracy during static or low-frequency operation, when the actuator
cannot keep the commanded position. It reduces the error between command and feedback by integrating
out offsets in the DC portion of the feedback.

54 MTS Material Test System Operation

6.0 Getting Started

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