Feed Forward Function - Panasonic MINAS A6N Series Operating Instructions Manual

5
Adjustment
Outline
When position control is used, positional deviation can be further reduced when
compared with deviation where control is made only by feedback, and response is also
improved, by calculating the velocity control command necessary for operation based
on the internal positional command, and by adding velocity feed forward to the speed
command calculated by comparison with position feedback.
The response time of the velocity control system is also improved by calculating torque
command necessary for operation based on the velocity control command and by adding
torque feed forward calculated by comparison with velocity feedback to the torque
command.
Related Parameter
For A6N series, the velocity feed forward and torque feed forward can be used.
Class No.
1
1
1
1
Usage Example of Velocity Feed Forward
When velocity feed forward filter is set to 50（0.5 ms）,After check to waveform graphic
functions of "PANATERM", the velocity feed forward gain is gradually increased with
the velocity feed forward filter set at approx. 50.The velocity feed forward will become
effective.The positional deviation during operation at a constant velocity is reduced as shown
in the equation below in proportion to the value of velocity feed forward gain.
Positional deviation [unit of command] = command speed [unit of command/s] /
positional loop gain [1/s] × (100 - velocity feed forward gain [%]) / 100
Rev.2.00
5. Manual Gain Tuning (Application)

Feed Forward Function

Title
Velocity feed forward
10
gain
Velocity feed forward
11
filter
Torque feed forward
12
gain
Torque feed forward
13
filter
Positional deviation
Motor speed
Command speed
Function
Multiply the velocity control command calculated
according to the internal positional command by the
ratio of this parameter and add the result to the speed
command resulting from the positional control process.
Set the time constant of 1st delay filter which affects the
input of velocity feed forward.
Multiply the torque command calculated according
to the velocity control command by the ratio of this
parameter and add the result to the torque command
resulting from the velocity control process.
Set up the time constant of 1st delay filter which affects
the input of torque feed forward.
Velocity feed forward gain
0[%]
Positional deviation within the
constant speed range will
50[%]
reduce as the velocity
forward gain is increased.
80[%]
Time
1
2
3
4
5
6
7
5-49