CANopen Programmer's Manual - Maccon.de

7: Profile Position, Velocity, and Torque Mode Operation CANopen Programmer’s Manual
Trapezoidal vs. S-Curve Profile: Some Design Considerations
Difference Between Trapezoidal and S-Curve Profiles
Here is a review of the differences between trajectory and S-curve profiles, and some design
considerations indicated by those differences:
Trapezoidal Profile S-Curve Profile Design Considerations
Unlimited jerk, operation not as
smooth.
Supports separate acceleration and
deceleration rates.
Supports modification of current move
parameters during current move,
allowing the execution of a series of
moves as a continuous profile.
Generally requires less torque than the
S-curve profile to complete an equal
move in equal time.
Limited jerk, smoother operation. If the application cannot tolerate jerk,
use S-curve.
Does not support separate
deceleration rate; uses acceleration
rate for acceleration and deceleration.
Does not support modification of
current move. A series of moves
requires a series of discrete profiles.
Generally requires more torque than a
trapezoidal profile to complete an
equal move in equal time, to make up
for time sacrificed for gentler starts and
stops.
If the application can tolerate jerk,
other features available exclusively in
trapezoidal profile may indicate its use.
If a separate deceleration rate is
critical, the trapezoidal profile is
indicated.
If current move modification is critical,
the trapezoidal profile is indicated.
Designers switching a profile from
trapezoidal to S-curve or lowering the
value of Trajectory Jerk Limit (index
0x2121, p. 202) might notice some
slowing. A higher Profile Acceleration
can be applied to compensate, but
watch out for amplifier and motor
limits.
198 Copley Controls