ADLINK Technology PCI-8254, User Manual

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104 Motion Control Theory
4.3.3.2 S-curve
An S-curve is a curve where the speed profile in the jerk area can
be represented by second-order profile. This helps to reduce
motor vibration at start up and stop time as indicated by points (t1,
t3, t5, t7) in figure below.
To shorten acceleration and deceleration time the linear section (t2,
t6) is inserted in these area to maintain the maximum acceleration
and so get an acceleration-time (A-T) chart in Trapezoidal.
Figure 4-19: S-curve's velocity, acceleration, and jerk versus time
Start velocity
End velocity
Max. velocity
Max. acceleration
Max. acceleration
Acc.
Dec.
Distance
Time
Time
Time
Tacc Tdec
Acceleration
Jerk
Velocity