Performance and limitations
Functional limitations
Correction of axis play
Example
Reverse
IREC
Dmin (Pr+)
Tmin
(Pr-) Dmin
Forward
The application for correcting axis play allows you to to obtain a positioning of the cams on a mechanical position whatever the direction.
In the example, recalibration is done in a backwards direction. The actual mechanical position is the value delivered by the encoder in the backward direction and the corrected value in the forward direction (end).
A safety distance (Dmin) is necessary between the position of the cames and the points of return. (Pr+ and Pr-). This distance corresponds to the value of axis play that is given when the adjusting the track.
In addition, the actual application of the correction (in forward direction in the example) is effective 4 ms after the change in direction. Also the cams must be positioned in such a way that the direction of development is correctly established:
4 ms (Tmin) before the switch to the first cam.
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Performance and limitations
Anticipation Example with anticipation
Tmin
With anticipation
(Re)Start
Forward
Cam switching is anticipated (in time) in relation to the actual crossing of thresholds.
The value is fixed by the anticipation factor (T anticip = n x 50 microseconds).
Following a (re)start or a change of direction, there is a delay (Tmin) until anticipation is applied. For correct operation, the first cam switch should not be expected before this delay.
T min = 2 x ( T anticip + 4 ms)
The delay required for the axis to reach speed can be added to t min to increase precision.
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