Siemens Sinumerik 840D Series Function Manual page 71

02.99
10.03
Optimization of
controller
P component
Optimization of
controller
D component
 Siemens AG, 2003. All rights reserved
SINUMERIK 840D/SIMODRIVE 611 digital, HLA Module (FBHLA) - 10.03 Edition
Relevant machine data:
MD 5406: SPEEDCTRL_GAIN_A (P gain of velocity controller A)
MD 5407: SPEEDCTRL_GAIN
MD 5408: SPEEDCTRL_GAIN_B (P gain of velocity controller B)
The theoretical characteristic data of the valve and cylinder are used to calcu-
late a suggested P gain value. The positive feedback area (MD 5406...MD 5408
<0) is included in the calculation to damp the drive system.
The adjustment to real conditions on the machine (special damping require-
ments) should be made according to the following criteria:
1. P component must be as positive as possible.
Optimization direction
< 0
2. The acceptable overshoot behavior represents the upper limit for the setting.
Note
P<0 (positive feedback) may be necessary to achieve the required damping
behavior. However, this setting will degrade the control quality. Friction in
particular causes prolonged settling times.
Threshold values (typical):
S
f P>0


S
f P<0, or around zero

S
f P>0

(f ...f see section 3.9.5 point 1...3)


Note
The P gain is indicated as a % of MD 5435: CONTROLLED_SYSTEM_GAIN.
P=-100% compensates the feedforward control.
Relevant machine data:
MD 5431: SPEEDCTRL_DIFF_TIME_A (derivative-action time T
MD 5432: SPEEDCTRL_DIFF_TIME
MD 5433: SPEEDCTRL_DIFF_TIME_B (derivative-action time T
MD 5430: SPEEDCTRL_PT1_TIME
The positive phase displacement of the derivative term can be used to actively
damp the controlled system for f
The derivative-action time constant/corner frequency parameters must be set to
values higher than the minimum natural frequency of valve and drive.
3.9 Fine adjustment and optimization
(P gain of velocity controller)
MD 5406
MD 5407
MD 5408
0 > 0
controller A)
(derivative-action time T
controller)
controller B)
(velocity controller smoothing time
constant)
type.

3 Startup
of velocity
V
of velocity
V
of velocity
V
3-71