Danfoss MCO 305 Design Manual page 52

MCO 305 Design Guide
This chart shows a typical 'short' movement where
maximum velocity cannot be reached. In this case,
the curve ramps-up the acceleration (using
JERKMIN) for as long as possible. This may or may
not reach maximum acceleration, depending on
how far away the target position is. There will then
be an acceleration ramp-down (using JERKMIN2),
followed immediately by a deceleration ramp-up
(using JERKMIN3). Again, depending on the target
position, there may or may not be a constant
deceleration segment. The curve ends with a
deceleration ramp-down to 0 velocity at the target
position.
The chart below shows an example where the motor is initially moving in the "wrong" direction and must
turn around and 'go back' to the target position. Since it must "turn around", the curve starts with a
deceleration ramp-up segment (using JERKMIN3) to maximum deceleration.
This will slow the speed down until it turns around.
Deceleration continues at maximum deceleration
until 0 velocity is reached and the direction
reverses. At exactly this point, the motor is now
'speeding up'" but in the other direction. From this
point, the curve is similar to a normal movement to
a target position, except that the whole curve is
inverted because the direction has changed. The
curve will have an acceleration ramp-up segment
(going backwards), it may or may not have a
constant acceleration segment, it will have an
acceleration ramp-down segment, it may or may
not have a constant velocity segment, it will have a
deceleration ramp-up segment, it may or may not
have a constant deceleration segment, and finally it
will have a deceleration ramp-down to the target
position.
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