Motion Control Engineering Nidec iControl, User Manual, Page: 104 / 453

4-15
Shaping the Speed Profile
iControl AC
4
• Final Approach to the Floor -
Final approach to the floor can be
customized in many different ways.
If tracking accuracy is very good, you
can probably program as follows on
the iView Pattern > Common tab:
• Leveling speed = Your desired
leveling speed. A typical number
is from 2 to 4.
• Leveling Distance = your choice. A typical number is from 0.12 to 0.25.
If tracking is not perfect, you can begin to introduce values in Leveling Speed and Distance that
allow you to mold the shape of the last few inches of approach.
• Excessive Motor Noise - If there is excessive motor noise or if acceleration or decelera-
tion feels rough, reduce Acceleration and/or Deceleration to provide the desired results.
Also, verify that:
• TORQMAX Drive - At lower speeds the drive automatically selects a lower carrier fre-
quency to produce more current from the drive. If required, adjust LX02 (LF.38)
Switching Frequency = 0. This will set the carrier frequency to 8 KHz. In addition,
reduce drive gain value, LC03, LC04 (LF.31) and LC08, LC09 (LF.32). DO NOT reduce
LC03, LC04 (LF.31) below 1200 or LC08, LC09 (LF.32) below 800 as a loss of control
will result.
• Bunching up of Deceleration Rate - If you are observing a bunching up of decelera-
tion rate (an increase in the deceleration rate as you reach the last few feet of approach to
the floor), it is generally due to inaccurate tracking.
• Increase lag compensation via Lag Delay on the controller’s Configuration > Pattern >
Common tab.
• Improve tracking or lower the value of the Flare Jerk and/or Approach Jerk parame-
ters. Remember that there are very real limits to how low you can set these parameters
(1.75 ft/s
3
is often as low as you can go).