Siemens SINUMERIK 840D Description Of Functions page 74

3 Start-Up
3.9 Fine adjustment and optimization
Optimization of
controller I
component
3-74
SINUMERIK 840D/SIMODRIVE 611 digital Descr. of Functions HLA Module (FBHLA) – 04.00 Edition
Test run:
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As long as the damping effect improves, the the D-action time value can be
raised further:
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Leave D-action time at its old value if the damping effect does not improve.
(see Fig. 3-22 – f )


The smoothing time constant is set to values w 1 ms as a function of the con-
trolled system for "calculate controller".
Owing to the fact that a derivative action amplifies the actual value noise, it is
necessary in this case to find a compromise between
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the derivative action (and thus vibration damping)
(set MD 5430: SPEEDCTRL_PT1_TIME as low as possible, i.e. high corner
frequency of D-action component or wide D-action frequency range)
and
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the noise of the manipulated variable.
Like the P component setting, the optimization criterion here is the maximum
acceptable overshoot of the closed velocity control loop.
The main area of application is the valve/cylinder combination f
with values T >>0.
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For applications f + f (see figs. 3-22, 3-23) improvements of the damping


characteristics are only to be expected at specific points when T
cases T =0 is the best choice.
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Note
A second iteration loop (optimize P and D components) with further improve-
ments can be connected in series downstream.
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Integrator/reset time (T
Objective:
Implementation:
Note
The I component is deactivated if T
zero (MD 5406=0, MD 5407=0, MD 5408=0).
)
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Elimination of errors in feedforward control channel.
T >5 ms, taking the overshoot behavior
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of the valve frequency response into account.
=0 (MD 5409) or if the P component is
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 Siemens AG 2000. All rights reserved
02.99
(see Fig. 3-24)

}0, in most
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