Delta RMC151 - Manual (Page 985)

9 Register Reference
Velocity control: %/(pu/sec 3 )
% = percent of maximum Control Output (default is 10V)
Range: ≥ 0
Default Value: 0
Description
The Double Differential Gain is available only on position and velocity axes with the High-
Order Control parameter set to Accel Control. The Double Differential Gain controls how
much of the Control Output is is added to the PFID Output due to the difference between
the Target Acceleration and the Actual Acceleration or Target and Actual Jerk for position
or velocity control, respectively. Position control is defined as when the Current Control
Mode is Position PID. Velocity control is defined as when the Current Control Mode is
Velocity PID.
Each gain of the axis contributes to the Control Output. The contribution from the Double
Differential Gain is called the Double Differential Output Term.
Advanced: I-PD Control
The Double Differential Gain controls how much the PFID Output is adjusted based on the
change in the Actual Acceleration or Actual Jerk for position or velocity control,
respectively. Position control is defined as when the Current Control Mode is Position I-
PD. Velocity control is defined as when the Current Control Mode is Velocity I-PD.
Tuning
See the Tuning Active Damping and Acceleration Control topic for details.
Definition
PositionPID
D
n
= (A
Target
n - A
Actual
n) x K
DD
Velocity PID
D
n
= (J
Target
n - J
Actual
n) x K
DD
Position I-PD
D
n
= - (A
Actual
n - A
Actual
n-1 ) x K
DD
Velocity I-PD
D
n
= - (J
Actual
n - J
Actual
n-1 ) x K
DD
where
D
n
= Double Differential Term at sample n [% of maximum Control Output]
A = Acceleration [pu/sec 2 ]
J = Acceleration [pu/sec 3 ]
K
DD
= Double Differential Gain [%/(pu/sec 2 ) or %/(pu/sec 3 )]
pu = position-unit
The Double Differential Gain units are: Percent of the maximum Control Output per
position units per second squared (pu/sec 2 ). The default value of the maximum Control
Output is 10V, but can be changed using the Output Scale parameter.
9.2.2.4.15. Active Damping Proportional Gain
Type: Axis Parameter Register
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