Rockwell Automation Allen-Bradley PowerFlex 750 Series

Rockwell Automation Publication 750-RM100A-EN-P - August 2019 75
Reference Motion Planners Chapter 9
Figure 21 - Acceleration Limiting
Acceleration and deceleration times can be readjusted to make up for the added dwell
time if required. However, times quickly go to zero when the limit approaches about half
the required maximum acceleration because the area under the curve becomes square.
Any further lowering of the limit beyond this point forces a velocity dwell to be added,
which increases acceleration and deceleration times.
Figure 22 - Acceleration Limiting with Adjusted Times
0 0.5 1 1.5 2 2.5
0
5000
Pos
[counts]
Compare Trajectories
Not Limitied
AccDec Lim = 1.5
AccDec Lim = 1.0
0 0.5 1 1.5 2 2.5
0
50
Vel
[RPM]
0 0.5 1 1.5 2 2.5
-2
0
2
Accel
[rev/sec
2
]
0 0.5 1 1.5 2 2.5
Time [sec]
-10
0
10
Jerk
[rev/sec
3
]
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
0
5000
Pos
[counts]
Compare Trajectories
Not Limitied
AccDec Lim = 1.5
AccDec Lim = 1.0
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
0
50
Vel
[RPM]
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
-2
0
2
Accel
[rev/sec
2
]
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
-10
0
10
Jerk
[rev/sec
3
]
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
Time [sec]
0
0.5
Energy
[rev
2
/sec
3
]