Closed-Loop Force Control - Siemens SINUMERIK 840D Description Of Functions

4 Firmware Drive Functions

4.4 Closed-loop force control

4.4 Closed-loop force control
Preconditions
Start-up of force
controller
Force limitation
Static friction
compensation
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SINUMERIK 840D/SIMODRIVE 611 digital Descr. of Functions HLA Module (FBHLA) – 04.00 Edition
S
Pressure sensors must be installed
S
Force limitation and/or static friction injection activated
(MD 5241: FORCECTRL_CONFIG)
S
Piston position must have been calibrated (see Section 3.9.4)
The letters have the fol-
lowing meaning:
A: Area
P: Pressure
F: Force
A
A
A
MD 5131
MD 5132
Fig. 4-11 Actual force measurement sensing
To start up the force controller, it is possible to redirect the measuring functions
and function generator from the velocity controller to the force controller by set-
ting bit 8 in MD 5650. In this setting, velocity setpoints are interpreted as force
setpoints in units of kN. This mode is deactivated by resetting MD 5650, bit 8
(mm/min → kN).
Force limitation is required
S
in certain machining processes for which the "Travel to fixed stop" function
must be implemented or
S
to work material in the machining of force profiles.
This compensation function is needed to compensate the effects of static fric-
tion occurring when the traversing direction changes (reduction of contour er-
rors, see e.g. circularity test).
A A
A B
F
B
F
A
B
P P
A B
Measured
value sensing
A
B
MD 5131
MD 5133
F F
A B
–
DF=F =F
piston actual
–
F
set
Force controller
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04.00
02.99
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