User`s manual

Functions

5-30

5. Functions

5.10 Offline auto-tuning function

The auto-tuning function is described here.

Offline auto-tuning is a function for automatically adjusting the servo system gain

according to the speed control cutoff frequency.

Offline auto-tuning operates the robot at a pre-determined operating pattern, estimates

the mover mass, and correctly sets the "Mover mass" (Fd-00) parameter. The control gain

is then automatically set from the "Speed control cut-off frequency" (Fd-01) that

determines the response of the speed control loop.

Note 1: It is not necessary to use this function when setting the parameters by following

the description in 6.3.3, "Reference graph for setting the acceleration and

position control cut-off frequency".

Note 2: To use the auto-tuning function, connect the robot to the equipment, and

operate it at the same load as when actually used. The servo system is optimally

adjusted for that load.

Note 3: During auto-tuning, the control mode for the speed control loop must be set to

"Speed PI control". (Cannot be correctly tuned under IP control.)

Note 4: Moment of inertia may not be estimated correctly, depending on the robot

model and operating conditions (load, etc.).

Note 5: During offline auto-tuning, information such as speed settings and torque data

can be checked as graphics on the user PC by using the TOP software for RD

series. So using the TOP software is recommended.

Note 6: When a PHASER series robot is used, magnetic pole position estimation must be

performed before this operation. For information on magnetic pole position

estimation,refer to section 5.17, "Magnetic pole position estimation action".

5.10.1 Offline auto-tuning method

(1) Parameter constants used in offline auto-tuning

Parameter constants used at this time are described below.

(a) Auto-tuning mode (FA-10)

This parameter constant permits you to run auto-tuning. To run auto-tuning, set it

to "oFL".

(b) Speed control cut-off frequency (Fd-01)

This parameter constant sets the response of the speed control loop. Set it within a

range where oscillation does not occur in the mechanical system. Setting this value

higher improves the response.

Note 1: In the case of a large load, the robot might oscillate unless the Fd-01

parameter is set small.