M
OVE
P
ROFILES
SD4840EK User Manual
ADVANCED MICRO CONTROLS INC.
22
Definition of Acceleration Types (continued)
S-Curve Accelerations (continued)
Triangular S-Curve Acceleration
When the Acceleration Jerk parameter is set low, Triangular S-Curve acceleration usually results. This occurs
because the programmed maximum acceleration value is not reached before the SD4840EK must start
decreasing the acceleration value as the move’s speed approaches its programmed maximum value. Triangu-
lar S-Curve is the smoothest form of acceleration, but the time needed to reached the move’s programmed
speed is increased. An example is shown in figure R2.3 where the acceleration and jerk settings results in a
move that takes twice as long as a Constant Acceleration move to achieve the same velocity.
Figure R2.3 Triangular S-Curve Acceleration
Additional information, including example move calculations, can be found in section 3,
A Simple Move
As shown in the figure below, a move from A (Current Position) to B (Target Position) consists of several
parts.
Figure R2.4 A Trapezoidal Profile
1) The move begins at point A, where the motor jumps from rest to the configured
Starting Speed
. The motor
then accelerates at the programmed
Acceleration Value
until the speed of the motor reaches the
Programmed Speed
. Both the Acceleration Value and the Programmed Speed are programmed when the
move command is sent to the SD4840EK.
2) The motor continues to run at the Programmed Speed until it reaches the point where it must decelerate
before reaching point B.
3) The motor decelerates at the
Deceleration Value
, which is also programmed by the move command, until
the speed reaches the Starting Speed, which occurs at the Target Position (B). The motor stops at this point.
Note that the acceleration and deceleration values can be different in the move.
Figure R2.4 above shows a Trapezoidal Profile. A Trapezoidal Profile occurs when the Programmed Speed is
reached during the move. This occurs when the number of steps needed to accelerate and decelerate are less
than the total number of steps in the move. Figure R2.5 below shows a Triangular Profile. A Triangular Pro-
file occurs when the number of steps needed to accelerate to the Programmed Speed and decelerate from the
Programmed Speed are greater than the total number of steps in the move. In this case, the profile will accel-
erate as far as it can before decelerating and the Programmed Speed is never reached.
Figure R2.5 A Triangular Profile
S
PEED
AC
C
EL
ER
A
T
IO
N
TIME
TIME
2t
2t
Programmed
Speed
SPE
ED
POSITION
A
B
SP
E
ED
POSITION
A
B
Содержание SD4840EK
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Страница 38: ...MOVE PROFILES SD4840EK User Manual ADVANCED MICRO CONTROLS INC 38 Notes...
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Страница 78: ...COMMAND DATA FORMAT SD4840EK User Manual ADVANCED MICRO CONTROLS INC 78 Notes...
Страница 94: ...INSTALLING THE SD4840EK SD4840EK User Manual ADVANCED MICRO CONTROLS INC 94 Notes...
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