Omron 8U0108-E1-01, User Manual

Page: 180 / 333

XtraDrive User Manual Chapter
6
: Servo Adjustment
6-13
The following wizard will help you to calculate your load inertia.
Estimation of equivalent load (
J
load
)
To tune your system, you should have an approximate estimation of the
Inertia (
J
load
) of the load attached to the motor.
If a cylinder load is mountain directly on motor axis
you should use
the following formula to calculate load inertia:
32
4
d l
J
load
× × ×
=
ρ π
Where ρ is the characteristic weight of the load [kg/m^3].
L is the length and d is the diameter of the load [m].
Estimation of Equivalent Load ( J
load
)
Case 1_ Load is a cylinder directly mounted or coupled to motor axis
:
32
4
d l
J
load
× × ×
=
ρ π
ρ is the density of the load material [kg/m^3]
L is the length
D is the diameter of the load [m]
Case 2_ Load is driven through a gear with ratio N
:
Equivalent load on motor is:
2
N
J
J
load
=
Case 3: Load is a mass driven by a ball screw
having pitch:
2
Pitch M
load
J
×
=
+ Jcoupling
J
load
, Kg.m
2
, M
Kg,
Pitch
meter/radian
Other Cases:
Make your own rough load inertia evaluations.