Siemens SINUMERIK 840Di Function Manual page 445

2.5.4 Position control with proportional-plus-integral-action controller
Function
For standard applications, the core of the position controller is a proportional-action controller
with the manipulation options described above connected in series upstream.
It is possible to connect an I component for special applications (e.g. electronic gear). The
resulting proportional-plus-integral-action controller then corrects the error between setpoint
and actual positions down to zero in a finite, settable time period when the appropriate
machine data are set accordingly.
Caution
When the proportional-plus-integral-action controller is active, overshoots occur in the actual
position. In this instance, you must decide whether this effect is admissible or acceptable for
the application in question. Expert knowledge of control engineering and measurements
taken using servo trace are absolutely essential when using this function. If incorrect settings
are made for the relevant machine data, there is a risk of damaging the machine, due to
possible instability.
Background
The transfer function of the proportional-plus-integral-action controller is as follows:
K
R
T :
n
Procedure
1. First optimize the position control loop as a proportional-action controller first using the
2. Increase the tolerances of the following machine data while measurements are being
3. Activate the position control loop as a proportional-plus-integral-action controller by
Velocities, Setpoint/Actual-Value Systems, Closed-Loop Control (G2)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
: P component gain
Integral time
tools described in the previous subsections.
taken to determine the quality of the position control with proportional-plus-integral-action
controller:
– MD36020 $MA_POSITIONING_TIME
– MD36030 $MA_STANDSTILL_POS_TOL
– MD36040 $MA_STANDSTILL_DELAY_TIME
– MD36400 $MA_CONTOUR_TOL
setting the following machine data:
MD32220 $MA_POSCTRL_INTEGR_ENABLE ; set value 1
Detailed Description
2.5 Optimization of the control
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