Advanced Micro Controls Inc. SMD17E2 User Manual page 47

SMD17E2 User Manual
S-Curve Acceleration Equations (continued)
Triangular S-Curve Acceleration (continued)
The value of the Acceleration Jerk parameter can now be easily calculated.
j = ------- -
t 2 
2a
j = ------- -
Ja 2a
s
-------- - = ------- -
100
Ja t = 200a
s
200
J = -------- -
This value represents the ideal Acceleration Jerk parameter value for a triangular S-curve acceleration. Set-
ting the value lower than this will result in a longer acceleration period, while setting the value above this will
result in a trapezoidal S-curve acceleration.
When a = a
s c
The above examples assume that you can increase the programmed acceleration value to keep the accelera-
tion time the same. If your constant acceleration value is the maximum your system will allow, then using 
S-curve accelerations will lengthen the time needed to accelerate to your desired speed.
In the case of Triangular S-curve accelerations where the Acceleration Jerk parameter is optimized at 200/t,
the value of "t" must be twice that of the acceleration period when constant acceleration is used. For example,
assume a equivalent constant acceleration of 20,000 steps/sec
tion value must remain at 20,000 steps/sec
eration Jerk parameter should be set to 50 (200/4.0)
20 Gear Drive, Plymouth Ind. Park, Terryville, CT 06786
Tel: (860) 585-1254 Fax: (860) 584-1973 http://www.amci.com
a
s
 a t  
j =
s
t
 
Ja
s
j = -------- -
 
t 100
s
Acceleration Jerk parameter = 200 / acceleration time
t
2
C
ALCULATING
2
that is applied for 2.0 seconds. If the accelera-
, then the acceleration phase will take 4.0 seconds and the Accel-
M P
OVE ROFILES
47