Function overview
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5.3.2
Relative positioning
In the case of relative positioning, the target position is added to the current position. Since no fixed zero is required,
referencing is not compulsory. It does, however, make sense in many cases, in order to bring the drive to a defined position.
Adding of relative positionings allows for example endless positioning in one direction for a trimming unit or a conveyor belt
(incremental dimension).
5.3.3
Absolute positioning
The target position is approached independent of the current position. In order to execute an absolute positioning we
recommend prior referencing of the drive. In the case of absolute positioning the target position is a fixed (absolute) position
referred to the zero or reference point.
5.3.4
Driving profile generator
Driving profiles are categorized in time-optimal and jerk-limited positioning. In the case of time-optimal positioning the
maximum set acceleration is used for starting and braking. The drive approaches the target in the shortest time possible, the
velocity profile is trapezoidal, and the acceleration profile is block-shaped.
In the case of jerk-limited positioning the acceleration profile is trapezoidal and the velocity profile is therefore of third order.
Since the acceleration changes continuously, the drive is extremely gentle on the mechanics.
a(t)
a(t)
a(t)
t
t
t
v(t)
t
v(t)
t
v(t)
t
at time optimal
jerk limit
jerk limit
Figure 5:
Driving profiles of item servo positioning controller C 1-Series
