ADLINK PCI-8158 - Manual (Page 57)

Operation Theory 47
4.2.3 Trapezoidal speed profile
A trapezoidal speed profile means the acceleration/deceleration
area follows a first-order linear velocity profile (constant accelera-
tion rate). The profile chart is shown as follows:
The area of the velocity profile represents the distance of this
motion. Sometimes, the profile looks like a triangle because the
desired distance is smaller than the area of given speed parame-
ters. When this situation happens, the motion controller will lower
the maximum velocity but keep the acceleration rate to meet the
distance requirement. The chart of this situation is shown as
below:
This kind of speed profile could be applied on velocity mode, posi-
tion mode in one axis or multi-axes linear interpolation and two
axes circular interpolation modes.
4.2.4 S-curve and Bell-curve speed profile
S-curve means the speed profile in accelerate/decelerate area fol-
lows a second-order curve. It can reduce vibration at the begin-
ning of motor start and stop. In order to speed up the acceleration/
deceleration during motion, we need to insert a linear part into