Weight And Inertia Settings - Epson VT Series Manipulator Manual

4.3 Weight and Inertia Settings

The WEIGHT and INERTIA (inertia moment and eccentricity) commands are for setting
the load parameters of the Manipulator. These settings optimize the Manipulator motion.
WEIGHT Setting
The WEIGHT command is for setting the load weight. The more the load weight
increases, the more the speed and acceleration/deceleration are reduced.
INERTIA Setting
The INERTIA command is for setting the inertia moment and the eccentricity of the load.
The more the inertia moment increases, the more the acceleration and deceleration of the
Arm #6 are reduced. The more the eccentricity increases, the more the acceleration and
deceleration for the Manipulator movement are reduced.
To ensure optimum Manipulator performance, make sure that the load (weight of the end
effector and work piece) and inertia moment of the load are within the maximum rating for
the Manipulator, and that Arm #6 does not become eccentric.
If the load or the inertia moment exceeds the ratings or if the load becomes eccentric,
follow the steps in the Setup & Operation 4.3.1 WEIGHT Setting and 4.3.2 INERTIA
Setting, to set parameters.
Setting parameters makes the operation of the Manipulator optimal, reduces vibration to
shorten the operating time, and improves the capacity for larger loads. In addition, it
reduces persistent vibration produced when the inertia moment of the end effector and
work piece is bigger.
The allowable load for VT series Manipulators is 6 kg at the maximum.
Due to the limitations of the moment and inertia moment shown in the table below, the
load (end effector weight + work piece weight) should also meet these conditions.
Allowable Load
Moment
The moment indicates amount of torque applied on the joint in order to support the gravity
on the load (end effector + work piece).
The moment increases as weight of the load and amount of eccentricity increase. As this
also increases the load applied on the joint, make sure to keep the moment within the
allowable value.
Inertia moment
The inertia moment indicates how difficult the load (end effector + work piece) to rotate
when the Manipulator joint starts to rotate (amount of inertia). The inertia moment
increases as weight of the load and amount of eccentricity increase. As this also increase
the load applied on the joint, make sure to keep the inertia moment within the allowable
value.
VT Rev.1
Joint Allowable Moment
Joint #4 12.0 N·m (1.22 kgf·m)
Joint #5
12.0 N·m (1.22 kgf·m)
Joint #6 7.0 N·m (0.71 kgf·m)
Setup & Operation 4. Setting of End Effectors
GD2/4 Allowable Moment of Inertia
0.3 kg·m
0.3 kg·m
0.1 kg·m
2
2
2
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