Siemens SINUMERIK 802D sl Function Manual

Compensation (K3)
11.4 Following error compensation (feedforward control)
Turning, Milling, Nibbling
226 Function Manual, 11/2012, 6FC5397-1CP10-5BA0
11.4 Following error compensation (feedforward control)
11.4.1 General
Axis-specific following error
The following error can be reduced to almost zero with the help of the feedforward control.
This feedforward control is therefore also called "following error compensation".
Particularly during acceleration in contour curvatures, e.g. circles and corners, this following
error leads to undesirable, velocity-dependent contour violations. The SINUMERIK 802D sl
control is equipped with the "Speed feedforward control" feedforward control type.
Activation/deactivation in part program
The feedforward control can be activated and de-activated by means of the following high-
level language elements in the part program:
● FFWON - Feedforward control ON
● FFWOF - Feedforward control OFF (activation setting)
With MD32630 FFW_ACTIVATION_MODE, the activation (via FFWON) or de-activation (via
FFWOF) of a specific axis can be determined:
● FFWON and FFWOF are used to activate and de-activate respectively the feedforward
control of all axes/spindles for which MD32630=1 is set.
● MD 32630 should therefore have identical settings for axes that interpolate with each
other.
The feedforward control should only be switched on or off while the axis/spindle is stationary
to prevent jerk. This is the responsibility of the programmer.
Conditions
The following points should be noted before the feedforward control is applied:
● Rigid machine behavior
● Precise knowledge about the machine dynamic response
● No sudden changes in the position and speed setpoints

Siemens SINUMERIK 802D sl Specifications

General

Brand	Siemens
Model	SINUMERIK 802D sl
Category	Controller
Language	English