6 - 8
6. GENERAL GAIN ADJUSTMENT
(c)Adjustment description
1) Speed loop gain (parameter No.PB09)
This parameter determines the response leve l of the speed control loop. Increasing this v alue
enhances response but a too high value will make the mec hanical system liable to vibrate. The actual
response frequency of the speed loop is as ind icated in the following expression.
Speed loop gain setting
Speed loop response
frequency(Hz) (1 ratio of load inertia moment to servo motor inertia moment) 2
2) Speed integral compensation (VIC: parameter No.PB10)
To eliminate stationary deviation against a command, the speed control loop is under proportional
integral control. For the speed integral c ompensation, set the time constant of this integral control.
Increasing the setting lowers the response level. However, if the load inertia moment ratio is large or
the mechanical system has any vibrator y element, the mechanical system is liable to vibrate unless
the setting is increased to some degree. The gu ideline is as indicated in the following express ion.
2000 to 3000
Speed loop gain setting/ (1 ratio of load inertia moment to
servo motor inertia moment setting)
Speed integral compensation
setting(ms)
3) Model loop gain (PG1: Parameter No.PB07)
This parameter determines the response leve l to a position command. Increasing the model loop gain
improves track ability to a position command, but a too hi gh value will make overshooting liable to
occur at the time of setting.
Model loop gain
guideline
Speed loop gain setting
(1 ratio of load inertia moment to servo motor inertia moment) to
1
4
1
8