Axis slip parameters

These are parameters in the UCC configuration file (.ini) that can be modified to adjust the axis slip mechanism. It can be useful to switch off axis slip for machines which have high drive stiction (static friction).


Default parameters:

In the .ini file under [ServoConfiguration]

SlipCheckDuration = 0.4
SlipDistancePercentage = 0.2
MaximumMoveSpeedSlipPercentage = 0.05

We have an AXIS SLIP if:

-  The axis has not moved by at least 20 % (0.2 - SlipDistancePercentage) of the estimated distance expected within a pre-defined time (0.4 - SlipCheckDuration). This will only be checked for speeds higher than 5 % (MaximumMoveSpeedSlipPercentage) of the maximum speed.


To switch off AXIS SLIP set the MaximumMoveSpeedSlipPercentage to 1.

- Axis Slip is checked for speeds higher than the maximum speed (which does not happen).
- The D to A increases but does not wait until it is in OVERDRIVE (generally 20 % higher than the maximum speed). 
- Contrary to the OVERDRIVE which disengages the motors, the Axis Slip leaves them engaged but goes through a FAST STOP and a BACK OFF (when an axis slip occurs).
- Axis slip is useful when a machine is pushing against something and cannot move. However, when a machine has inherently high STICTION, it becomes a problem.


See also