Siemens SINAMICS S120 System Manual page 163

● Axis has been referenced (homed)
● The piston has been calibrated (r1407.3 = 1)
● The dead volume has been correctly parameterized (p0341, p0315, p0346 to p0348)
Velocity threshold
The velocity threshold (p1552) is the threshold, below which standstill and therefore stiction
are recognized.
When this threshold is fallen below, the force controller ensures that the force set in p1554 or
p1555 is controlled as long as the drive is at standstill (stationary).
Which of the two force setpoints is applied (p1554 or p1555) is determined by the sign of the
velocity setpoint.
Cutoff limit
The force controller is deactivated just before the setpoint is reached via the cutoff limit
(p1554) to prevent overshoots occurring while the servo solenoid valve is operational.
If p1554 is set to 100 %, then the force controller is not switched off until the force setpoint
(p1555 or p1556) is reached or unless the drive moves beforehand. This setting results in
overshoots in the actual velocity value.
Cylinder friction force
The cylinder friction force at a positive or negative velocity is set in p1555 or p1556
respectively.
Allowance must be made for the force of weight applied to the cylinder in p1555 or p1556
(e.g. with a cylinder mounting position other than 0 degrees, p0344). The value to be set can
be read in r0080 when the cylinder is moved slowly (e.g. in the JOG mode) in the positive or
negative direction.
If the force of weight applied to the cylinder varies as a function of load, then static force
compensation with force controller cannot be utilized.
Overview of important parameters (see SINAMICS S120/S150 List Manual)
• p1400[0...n]
• p1552[0...n]
• p1554[0...n]
• p1555[0...n]
• p1556[0...n]
Hydraulic Drive
System Manual, 04/2015, 6SL3097-4BA00-0BP1
Closed-loop control configuration
Stiction velocity threshold
Stiction shutdown rate action
Stiction force velocity positive
Stiction force velocity negative
Drive functions
5.4 Force control
163