User`s manual

Using the Electronic CAM Feature
GFK-1742A Chapter 16 Using the Electronic CAM Feature 16-9
16
Blending Sectors
The process applied to blend adjacent sectors depends on their curve-fit order. The following
descriptions cover the possible scenarios.
1
st
order to 1
st
order
No action is taken to smooth the transition between successive linear sectors (that is, with curve-fit
order of 1). The profile simply connects the end point of one sector to the start point of the next
with a straight line.
1
st
order to 2
nd
order
When a quadratic (2
nd
order) sector follows a linear (1
st
order) sector, the polynomial coefficients
for the first segment of the quadratic sector are calculated so that the slope of the profile is equal on
either side of the starting point of that sector. That is, the initial slope of the quadratic sector is
made equal to the final slope of the linear sector.
2
nd
order to 1
st
order
When a linear (1
st
order) sector follows a quadratic (2
nd
order) sector no action is taken to smooth
the transition. This type of transition is not recommended (if it is avoidable) as it may result in
drastic velocity or acceleration changes on the controlled servo.
2
nd
order to 2
nd
order
When a quadratic (2
nd
order) sector follows another quadratic (2
nd
order) sector the polynomial
coefficients for the first segment of the second quadratic sector are calculated so that the slope of
the profile is equal on either side of the starting point of that sector. That is, the initial slope of the
second quadratic sector is made equal to the final slope of the first quadratic sector.
2
nd
order to 3
rd
order
When a cubic (3
rd
order) sector follows a quadratic (2
nd
order) sector the polynomial coefficients
for the first segment of the cubic sector are calculated so that the slope of the profile is equal on
either side of the starting point of that sector. That is, the initial slope of the cubic sector is made
equal to the final slope of the quadratic sector.
3
rd
order to 2
nd
order
When a quadratic (2
nd
order) sector follows a cubic (3
rd
order) sector the polynomial coefficients
for the first segment of the quadratic sector are calculated so that the slope of the profile is equal on
either side of the starting point of that sector. That is, the initial slope of the quadratic sector is
made equal to the final slope of the cubic sector.
3
rd
order to 3
rd
order
When two cubic (3
rd
order) sectors are adjacent, the slopes of the profile before and after the point
they meet are made equal. Also, the 2
nd
derivatives of the profile before and after the point the