Omron R88M-W60010T User Manual page 313

Operation
• Predictive control for positioning (Pn150.1 = 1)
This function operates by anticipating future position commands. It starts operation simultaneous-
ly with a command and is effective in shortening positioning time.
The tracking is different from the command tracking shape. With machinery that is prone to vibra-
tion, the vibration may increase when stopping. In that case, even with a positioning application,
use predictive control for tracking.
Predictive control for
positioning:
Enables high-speed positioning.
Position
Position command
Predictive Control Acceleration/Deceleration Gain (Pn151)
■
As this value is increased, the settling time is shortened without significantly changing the maximum
position deviation. If the value is set too high, overshooting will occur. The following diagram shows
an example of position deviation during operation by a trapezoidal speed command. Raising the pre-
dictive control acceleration/deceleration gain changes the position deviation from the dotted line to
the solid line and shortens the settling time.
Position deviation
Predictive Control Weighting Ratio (Pn152)
■
As this value is increased, the tracking deviation is reduced. If the positioning completed range is
large, this is also effective in shortening the settling time. If the value is set too high, torque vibration
and overshooting may occur. The following diagram shows an example of position deviation during
operation by a trapezoidal speed command. Raising the predictive control weighting ratio changes
the position deviation from the dotted line to the solid line and lowers the tracking deviation.
Predictive control for tracking:
Retains command shape.
Position propor-
tional control
Time
Predictive control acceleration/deceleration
gain (Pn151) is raised.
Time
Chapter 4
4-117