Mitsubishi Electric FR-V500 Instruction Manual page 173

Orientation (Pr. 350 to Pr. 362, Pr. 393 to Pr. 399)
(4) Fine adjustment of the orientation stop position (Pr. 361 "position shift"
(factory setting: 0))
The orientation stop position will deviate by the value set x 360
Finely adjust the position by changing this setting value in 10 increments.
The orientation stop position will differ according to the direction that the encoder is installed in.
(Refer to the drawings below.)
Motor
View from A
Foward
1024
(90°)
(5) Adjustment of the servo rigidity
Pr. 396 orientation speed gain (P term)
"
Pr. 397 orientation speed integral time
"
Pr. 398 orientation speed gain (D term)
"
Pr. 362 orientation position loop gain
"
• To increase the servo rigidity*
1) Increase the Pr. 362
orientation stop.
2) Increase Pr. 396 and Pr. 397 at the same rate.
Generally adjust Pr. 396 in the range from 10 to 100, and Pr. 397 from 0.1 to 1.0s.
(Note that these do not need to be set to the same rate.)
<Example>
When the Pr. 396 value is multiplied by 1.2, divide the Pr. 397 value by 1.2.
If vibration occurs during orientation stop, the scale cannot be raised any higher.
3) Pr. 398 is the lag/advance compensation gain.*
The limit cycle can be prevented by increasing the value, and the running can be stopped stably. However, the
torque in regard to the position deviation will drop, and the motor will stop with deviation.
POINT
Application of lag/advance control and PI control
PI control can be applied by setting Pr. 398 to 0. Normally, the lag/advance control is selected. Use PI control in
the following cases.
When using a machine with a high spindle stationary friction torque and requires a stopping position precision.
REMARKS
*1. Servo rigidity: This is the response when a position control loop is configured.
When the servo rigidity is raised, the holding force will increase, the running will stabilize, but vibration will occur easily.
When the servo rigidity is lowered, the holding force will drop, and the setting time will increase.
*2. Limit cycle*:This is a phenomenon that generates ± continuous vibration centering on the target position.
*3. Rocking: Movement in which return occurs if the stopping position is exceeded.
Case 1
Encoder
Belt
A
Reverse
3072
(270°)
2048
(180°)
(factory setting: 60)
"
(factory setting: 0.333)
"
(factory setting: 1)
"
(factory setting: 10)
"
during orientation stop in Pr. 396 or Pr. 397, adjust with the following procedures.
1
orientation position loop gain
"
2
/ Pr. 851 number of encoder pulses
° "
Case 2
Encoder
Motor
Belt
A
View from A
Forward
Reverse
3072 1024
(270°) (90 ° )
2048
(180 ° )
value to the extent that rocking does not occur during
"
164
x4.
"