Mitsubishi Electric FR-E800 Instruction Manual page 478

NOTE
• The following are precautions for the orientation operation under V/F control.
• Couple the encoder with the motor shaft that stops the shaft at the specified position. Couple it with the speed ratio of 1:1
and without any mechanical looseness.
• To ensure correct positioning, the encoder must be set in the proper rotation direction, and the A and B phases must be
connected correctly.
• If the pulse signal from the encoder stops due to encoder signal loss or other factors during orientation, orientation may not
be completed.
• The X13 signal is valid until the speed reaches the orientation speed and the encoder Z phase pulse is detected.
• To terminate orientation, the start signal (STF or STR) must be first switched OFF, and then the X22 signal must be switched
OFF. As soon as this X22 signal is switched OFF, orientation control ends.
• When performing orientation control, properly set Pr.350 Stop position command selection.
If the values set are incorrect, proper orientation control will not be performed.
• Orientation control is disabled under the following conditions:
During auto tuning, during PID control, when the automatic acceleration/deceleration function is enabled, when the brake
sequence function is enabled, or when the second function is enabled
• If Signal loss detection (E.ECT) is activated while the X22 signal is ON, check for a break in the cable of the Z phase of the
encoder.
 Servo rigidity adjustment (Pr.362, Pr.396 to Pr.398) (Vector control)
• To increase the servo rigidity
Orientation speed integral time, make adjustments with the following procedures.
1.
Increase the Pr.362 Orientation position loop gain setting value to the extent that rocking
orientation stop.
2.
Increase Pr.396 and Pr.397 at the same rate.
Normally, adjust Pr.396 in the range from 10 to 100, and Pr.397 from 0.1 to 1.0 s.
(Note that these do not need to be set to the same rate.)
<Example>
When the Pr.396 setting value is multiplied by 1.2, divide the Pr.397 setting value by 1.2.
If vibration occurs during orientation stop, the scale cannot be raised any higher.
3.
Pr.398 Orientation speed gain (D term) is the lag/advance compensation gain.
*3
The limit cycle can be prevented by increasing the value, and operation can be stopped stably. However, the
torque decreases in relation to the position deviation, and the motor stops with deviation.
*1 Servo rigidity: The response when a position control loop is configured.
When the servo rigidity is raised, the holding force increases and operation becomes stable, but vibration occurs more easily.
When the servo rigidity is lowered, the holding force decreases, and the settling time increases.
*2 Rocking: Movement in which return occurs when the stopping position is exceeded.
*3 Limit cycle: A phenomenon that generates ± continuous vibration centering on the target position.
• Application of lag/advance control and PI control
PI control can be applied by setting Pr.398 = "0". Normally, use the lag/advance control. PI control should be used when using
a machine with a high spindle static friction torque requires a stop position accuracy.
• During orientation control, gain cannot be adjusted using Pr.820 Speed control P gain 1, Pr.821 Speed control integral time
1, and Pr.698 Speed control D gain.
*1
during orientation stop using Pr.396 Orientation speed gain (P term) or Pr.397
*2
does not occur during
15. (A) Application Parameters
15.5 Orientation control
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