THORLABS KBD101 User Manual page 61

velocity
maximum
velocity (v)
The S-curve profile is a trapezoidal curve with an additional 'Jerk' parameter, which limits
the rate of change of acceleration and smooths out the contours of the motion profile.
Jerk Setting – This parameter is specified in mm/s
0 to 46566139. It is used to specify the maximum rate of change in acceleration in a
single cycle of the basic trapezoidal curve.
In this profile mode, the acceleration increases gradually from 0 to the specified
acceleration value, then decreases at the same rate until it reaches 0 again at the
specified velocity. The same sequence in reverse brings the axis to a stop at the
programmed destination position.
Example
1 2
A
J
The figure above shows a typical S-curve profile. In segment (1), the S-curve profile
drives the axis at the specified jerk (J) until the maximum acceleration (A) is reached.
The axis continues to accelerate linearly (jerk = 0) through segment (2) . The profile
then applies the negative value of jerk to reduce the acceleration to 0 during segment
(3). The axis is now at the maximum velocity (V), at which it continues through
segment (4). The profile then decelerates in a similar manner to the acceleration
phase, using the jerk value to reach the maximum deceleration (D) and then bring the
axis to a stop at the destination.
acceleration (slope) a
Fig. 6.7 Graph of a trapezoidal velocity profile
3 4
V
-J
Time
Fig. 6.8 Typical S-Curve Profile
Brushless DC Servo Driver K-Cube
3
and accepts values in the range
5 6 7
-J
D
J
time
A - acceleration
D - deceleration
V - velocity
J - jerk
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