
5.FEED FUNCTIONS PROGRAMMING B-63784EN/01
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- Acceleration/deceleration clamping near a base circle
If an acceleration calculated from the curvature radius of an involute
curve exceeds the value specified in the parameter, the feedrate in the
tangent direction is controlled so that the acceleration specified in the
parameter is not exceeded. An acceleration not exceeding a limit can be
maintained, so that efficient feedrate control tailored to the machine
limits can be exercised. Moreover, smooth, continuous feedrate control
can be exercised to reduce stress and strain in machining near a base
circle. When calculating acceleration, the curvature radius of an
involute curve and a feedrate in the tangent direction are used with a
circular acceleration expression, as follows:
Acceleration = F × F/R
F : Feedrate in the tangent direction
R : Curvature radius
Specify the maximum allowable acceleration in parameter No. 1663.
If a calculated acceleration/deceleration value is greater than a
maximum allowable value, the feedrate is clamped according to the
formula below:
Clamp feedrate = ationon/deceleraccelerati allowable maximum × radius curvature
If a resultant clamp feedrate is less than the minimum allowable
feedrate specified in parameter No. 1491, the minimum allowable
feedrate is used as a clamp feedrate.
CAUTION
A maximum allowable acceleration/deceleration
value is to be specified for each axis. So, use the
smaller of the maximum allowable
acceleration/deceleration values for the two involute
interpolation axes. If one of the values for the two
involute interpolation axes is 0, the
acceleration/deceleration clamp function is not
disabled, but the non-zero value is used as a
maximum allowable acceleration/deceleration value.
If both values are 0, the acceleration/deceleration
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