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Acceleration Setting
Profiling Condition
AA > ½ A, but AA < A
S-curve profile with a variable period of constant acceleration. Increasing the AA value above
the pure S-curve level (AA > ½ A), the time required to reach the target velocity and the target
distance is decreased. However, increasing AA also increases jerk.
AA = ½ A
Pure S-curve (no period of constant acceleration—smoothest motion).
AA = A
Trapezoidal profile (but can be changed to an S-curve by specifying a new AA value less than A).
AA < ½ A; or AA > A
When you issue the GO command, the move will not be executed and an error message,
*INVALID CONDITIONS FOR S_CURVE ACCELERATION—FIELD n, will be displayed.
AA = zero
S-curve profiling is disabled. Trapezoidal profiling is enabled. AA tracks A. (Track means the
command's value will match the other command's value and will continue to match whatever
the other command's value is set to.) However, if you enter an average decel command (e.g.,
ADA, HOMADA, etc.) equal to zero, you will receive the "INVALID DATA-FIELD n" error.
AA ≠ zero and AA ≠ A
S-curve profiling is enabled only for standard moves. All subsequent standard moves for that
axis must comply with this equation: ½ A ≤ AA < A.
AA > ½ A
Average accel/decel is raised above the pure S-curve level; this decreases the time required to
reach the target velocity and distance. However, increasing AA also increases jerk. After
increasing AA, you can reduce jerk by increasing A, but be aware that increasing A requires a
greater torque to achieve the commanded velocity at the mid-point of the acceleration profile.
No AA value ever entered
Profile will default to trapezoidal. AA tracks A.
If you never change the
A
or
However, once you change
A deceleration
For example, if you never change the
once you change
, the
AD
ADA
Calculating Move Times. The calculation for determining S-curve average accel and decel move times is
as follows (calculation method identical for S-curve and trapezoidal moves):
Scaling affects the
average acceleration (
AA
acceleration (
,
, etc.). See page
A
AD
NOTE: Equations for calculating jerk are provided on page 17.
Programming Example
; In this example, prog1 executes a pure S-curve and takes 1 second
; to reach a velocity of 5 rps; prog2 executes a trapezoidal profile
; and takes 0.5 seconds to reach a velocity of 5 rps.
SCALE0
; Disable scaling
DEL Prog1 ; Delete program called prog1
DEF Prog1 ; Begin definition of prog1
MA0
; Select incremental positioning mode
D40000
; Set distance to 40,000
A10
; Set max. accel to 10 revs/sec/sec
AA5
; Set avg. accel to 5 revs/sec/sec
AD10
; Set max. decel to 10 revs/sec/sec
ADA5
; Set avg. decel to 5 revs/sec/sec
V5
; Set velocity to 5 revs/sec
GO1
; Execute motion
END
; End definition of prog1
DEL Prog2 ; Delete program called prog2
DEF Prog2 ; Begin definition of prog2
MA0
; Select incremental positioning mode
D40000
; Set distance to 40,000
A10
; Set max. accel to 10 revs/sec/sec
AA10
; Set avg. accel to 10 revs/sec/sec
AD10
; Set max. decel to 10 revs/sec/sec
ADA10
; Set avg. decel to 10 rev/sec/sec
V5
; Set velocity to 5 revs/sec
GO1
; Execute motion
END
; End definition of program #2
16
Gemini GV6K/GT6K Command Reference
AA
deceleration commands,
,
AA
deceleration will no longer track changes in
or
command values,
AD
ADA
command value will no longer track the changes in the
Velocity
Time =
or
Time =
A
avg
,
, etc.) the same as it does for the
AA
ADA
19
for details on scaling.
(see move profile drawings below)
www.comoso.com
AA
deceleration will track
AA
will track the
ADA
AA
AA
∗
2 Distance
A
avg
A
V
S-Curve
0
1
V
Trapezoidal
0
1
Move profiles
acceleration
.
AA
acceleration.
command value. But
command value.
maximum
T
2
3
T
2
3
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