Epson LS20, Manipulator Manual, Page: 57 / 176

Setup & Operation 4. Setting of End Effectors
LS20 Rev.4 45
4.3.2 Inertia Setting
Moment of Inertia and the Inertia Setting
The moment of inertia is defined as “the ratio of the torque applied to a rigid body and its
resistance to motion”. This value is typically referred to as “the moment of inertia”,
“inertia”, or “GD
2
”. When the Manipulator operates with additional objects (such as an
end effector) attached to the shaft, the moment of inertia of load must be considered.
CAUTION
■
The moment of inertia of the load (weight of the end effector and work piece)
must be 0.45 kg·m
2
or less. The LS20 series Manipulators are not designed to
work with a moment of inertia exceeding 0.45 kg·m
2
. Always set the moment of
inertia parameter to the correct moment of inertia. Setting a value that is smaller
than the actual moment of inertia may cause errors, excessive shock, insufficient
function of the Manipulator, and/or shorten the life cycle of parts/mechanisms.
The acceptable moment of inertia of load for a LS20 series Manipulator is 0.05 kg

m
2
at
the default rating and 0.45 kg

m
2
at the maximum. When the moment of inertia of the
load exceeds the rating, change the setting of the moment of inertia parameter of the
Inertia command. After the setting is changed, the maximum acceleration/deceleration
speed of Joint #4 at PTP motion corresponding to the “moment of inertia” value is set
automatically.
Moment of inertia of load on the shaft
The moment of inertia of load (weight of the end effector and work piece) on the shaft can
be set by the “moment of inertia” parameter of the Inertia command.
Enter a value into the [Load inertia:] text box on the [Inertia] panel ([Tools]-[Robot
Manager]). (You may also execute the Inertia command from the [Command Window].)
Automatic acceleration/deceleration setting of Joint #4 by Inertia
(moment of inertia)
0 0.10 0.20 0.30 0.40 (kg
･
m
2
)
Moment of inertia setting
120
100
80
60
40
20
(%)
115
12.8
7.4
100
EPSON
RC+