ADLINK Technology HSL-4XMO, User Manual

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38 Operation Theory
There are several parameters that need to be set in order to make
a S-curve move. They are:
X
Pos: target position in absolute mode, in units of pulses
X
Dist: moving distance in relative mode, in units of pulses
X
StrVel: start velocity, in units of PPS
X
MaxVel: maximum velocity, in units of PPS
X
Tacc: time for acceleration (StrVel -> MaxVel), in units of
seconds
X
Tdec: time for deceleration (MaxVel -> StrVel), in units of
seconds
X
VSacc: S-curve region during acceleration, in units of PPS
X
VSdec: S-curve region during deceleration, in units of PPS
Figure 4-9: S-curve Profile Motion
Normally, the accel/decel period consists of three regions, two
VSacc/VSdec curves and one linear. During VSacc/VSdec, the
jerk (second derivative of velocity) is constant, and, during the lin-
ear region, the acceleration (first derivative of velocity) is constant.
In the first constant jerk region during acceleration, the velocity
goes from StrVel to ( VSacc). In the second constant jerk
region during acceleration, the velocity goes from (MaxVel –
StrVel) to MaxVel. Between them, the linear region accelerates