Festo Контроллер позиционирования CPX-CMAX - Manual (Page 385)

B. Basic controlling principles
B−43
Festo P.BE−CPX−CMA X−CONTROL−EN en 0908NH
B.8.4 Behaviour of standstill control
After completion of a positioning task, position control is
switched to force control to keep the drive at a standstill.
Reversing does not occur at the time of reaching the standstill
condition, but:
ć 200 ms later or
ć when the change in the actual force after reaching the
standstill condition is more than 25% of the friction hysĆ
teresis.
The standstill condition has been reached if
ć the tolerance has been reached once and
ć the position error is within 70% of the permissible tolerĆ
ance window and
ć the speed is less than 4 mm/s and
ć the chamber pressures are smaller than the supply presĆ
sure (especially in vertical operation with large masses,
chamber pressures that are larger than the supply presĆ
sure may briefly occur).
If the drive leaves its tolerance window for standstill position
during standstill control or if the speed exceeds 4 mm/s, then
the position controller is activated to move the drive back to
its target position. If the drive has reached the target position
and the standstill conditions, standstill control is re−activated,
provided one of the stated conditions for the delay time or
force control is fulfilled.