Mitsubishi Electric MELDAS C6 Programming Manual page 270

13. Program Support Functions
Vector accuracy interpolation
When a fine segment is commanded and the angle between the blocks is extremely small (when
not using optimum corner deceleration), interpolation can be carried out more smoothly using the
vector accuracy interpolation.
Feed forward control
With this function, the constant speed error caused by the position loop control of the servo system
can be greatly reduced. However, as machine vibration is induced by the feed forward control,
there are cases when the coefficient cannot be increased.
In this case, use this function together with the smooth high gain (SHG) control function and stably
compensate the delay by the servo system's position loop to realize a high accuracy. As the
response is smoother during acceleration/deceleration, the position loop gain can be increased.
(1) Active feed forward control
Command during acceleration/
deceleration before interpolation
Command during acceleration/
deceleration after interpolation
Commanded path
+
−
+
Machine error
compensation
amount
262
13.12 High-accuracy control
Vector accuracy interpolation
Active feed forward control
Kp
+
Kv
−
S
Kp : Position loop gain
Kv : Speed loop gain
M : Motor
S : Segment
M
Detector