Real time auto gain tuning

Outline

Load inertia of the machine is estimated at real time, and the optimum gain is set up automatically based on the estimated result. A load, which has a resonance, also can be handled owing to the adaptive fil- ter.

Position/speed

Gain auto

Filter auto

 

 

setting

tuning

Torque

Motor

command

 

 

command

Position/speed

Applied

current

 

Current

 

control

filter

control

Motor

 

 

Operation command under

 

 

 

 

actual operation conditions

 

 

 

 

 

Resonant frequency estimate

 

 

 

Load inertia estimate

 

 

 

 

Real time auto

 

 

 

 

gain tuning

 

Motor

 

 

 

 

 

 

 

 

speed

 

 

 

 

Encoder

 

 

Servo driver

 

 

Application range

Under the following conditions, the real time auto gain tuning may not function properly.

In such case, use the normal mode auto gain tuning (see page 193 "Adjustments") or manual gain tuning (see page 197 "Adjustments").

 

Conditions under which the real time auto gain tuning is prevented from functioning

 

• When the load inertia is smaller/larger than the rotor inertia

Load inertia

(3 times or less; or 20 times or more)

 

• When the load inertia fluctuates

Load

• When the machine stiffness is extremely low

• When any unsecured part resides in such as backlash, etc.

 

 

• In case of a continuous low speed operation under 100 [r/min].

Operation pattern

• In case of soft acceleration/deceleration under 2000 [r/min] per 1 [s].

 

• When acceleration/deceleration torque is smaller than unbalanced load/viscous friction torque.

 

 

How to use

[1]Stop the motor (Servo-OFF).

[2]Set up Pr21 (Real-time auto tuning set-up) to 1 – 6. Set up value before shipment is1.

Setting value

Real-time auto tuning

Changing degree of load inertia during operation

Adaptive filter

0

Not used

No

[1]

 

Little change

 

2

 

Change slowly

Yes

3

Used

Change s haply

 

4

 

Little change

 

5

 

Change slowly

No

6

 

Change s haply

 

7

Not used

Yes

When the changing degree of the load inertia is too large, set Pr21 to 3 or 6.

When the influence of resonance is conceivable, select “adaptive filter YES”.

[3]Set 0 – 2 to Pr22 (real-time auto tuning machine stiffness).

[4]Turn the servo ON to operate the machine ordinarily.

[5]To increase the response performance, gradually increase Pr22 (Machine stiffness at real-time auto tuning). When any noise or vibration is found, decrease the Pr22 to a lower value soon.

[6]To store the result, write the data into the EEPROM.

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Panasonic MINAS A3 Series manual Real time auto gain tuning, Outline, Application range, How to use