Feedforward control

Feedforward control
(following error compensation)

Function

Axial following errors can be reduced to almost zero with feedforward control. This feedforward control is therefore also called following error compensation. Particularly during acceleration in contour curvatures, e.g. circles and corners, the axial following error leads to undesirable, velocity-dependent contour violations.

• Velocity-dependent speed feedforward control
  The following error can be reduced almost to zero at constant velocity with this mode of feedforward control.
• Acceleration-dependent torque feedforward control
  In order to achieve precise contours even when the demand for dynamics is at its highest, the torque feedforward control – provided the settings are right – can compensate the following error almost completely, even during acceleration.

Benefits

• Reduction of unwanted, speed-dependent contour errors during acceleration processes on contour curvatures, e.g. circles and corners
• Excellent machining precision, even at high path velocities