Specifications

Drive set-up procedure

14.4.3

Spline interpolation

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14.4.3 Spline interpolation

 General spline interpolation

Set the following machine data as the conditions for general spline interpolation to be

enabled within CNC.

• MD28530 PATH_VELO_SEGMENTS

Meaning: Number of polynomial spline per block

Setting this value allows the feed speed to be controlled to have better

waveform.

Standard setting value: 5

• MD28540 ARCLENGTH_SEGMENTS

Meaning: Number of polynomial spline within a single spline curve

Setting this value allows the deviation of feed speed to decrease on the

curve sections.

Standard setting value: 10

 Spline interpolation with NC program command

This allows the curve interpolation for linear blocks with the spline interpolation.

There are 3 types of spline curve for interpolation:

• A spline (Akima spline): Spline interpolation which always goes through the instructed

points. The radius of curvature does not vary continuously.

• B spline (B-spline): Smooth spline interpolation which goes by the instructed points.

• C spline (Cubic spline): Spline interpolation which always goes through the instructed

points and whose radius of curvature varies continuously on the instructed points.

A spline

B spline

C spline