Force Limitation; Stiction Compensation; Stiction Compensation Using The Force Controller - Siemens SINAMICS S120 System Manual

Drive functions
5.4 Force control
5.4.1

Force limitation

Force limitation threshold (plus/minus) around the force of weight and weight force limiting.
If a pressure sensor is installed and connected for the pressures at A and B, the force
limitation in p1400 can be activated.
In the case that the value set in the parameters p1520 and p1521 plus the force due to
weight (p1532) may be exceeded – or if there is a possibility that the force due to weight
(p1532) minus the value set in the parameters p1520 and p1521 is fallen below, then the
force controller ensures that the set cylinder force values are limited to the corresponding
values.
Since only the cylinder force is measured and controlled, it may be necessary to take into
account the force due to weight in parameter p1520 and the friction force in parameters
p1521 and p1532.
An additional force limitation value, with the same effect as p1520/p1521, can be entered
from the control, e.g. when traversing to the fixed stop. The lower of the two force limit
thresholds is then applied.
Overview of important parameters (see SINAMICS S120/S150 List Manual)
• p1400[0...n]
• p1520[0...n]
• p1521[0...n]
• p1532[0...n]
5.4.2

Stiction compensation

5.4.2.1

Stiction compensation using the force controller

If the pressures at A and B are sensed, then the stiction compensation using the force
controller can be activated (p1400.2=1).
Static force compensation using the force controller should not be activated if the cylinder is
required to hold a fluctuating force due to weight. In addition, the offset of the valve control
voltage and the piston must already have been calibrated. Parameters p1552 to p1556 can
be calibrated using the circularity test.
Preconditions
The following preconditions must be fulfilled to use stiction compensation with the force
controller:
● Pressure sensors must be available for p
● The force controller must have already been commissioned.
● External force (F
162
Closed-loop control configuration
CO: Force limit upper/motoring
CO: Force limit lower/regenerative
CO: Force offset, force limit
) does not change.
center
and p
A B
System Manual, 04/2015, 6SL3097-4BA00-0BP1
Hydraulic Drive