YASKAWA NX100 Instructions Manual page 104

8.4 ARM Control
Center of gravity position: xg, yg, zg (Unit: mm)
The center of gravity position of the installed tool is set as the position in the flange coordi-
nates.
Since it is usually difficult to get a strict center of gravity position, it can be set with a rough
value. Presume and set a center of gravity position roughly from outline of the tool.
Set the value when the center of gravity position of the installed tool is clear from specifica-
tions, etc.
Moment of inertia at the center of gravity: lx, ly, lz (Unit: kg m
It is an moment of inertia of the tool at the center of gravity position.
The value is calculated around the each axis of the coordinates which is in parallel to the
flange coordinates and which home position is the center of gravity position of the tool.
It is not required to set a correct value, however, it is recommended to set a value slightly
larger than the actual value.
This setting is used to calculate the moment of inertia which loads to each axis of the manipu-
lator. However, the moment of inertia at the center of gravity does not need to be set when
this data is small enough for the moment of inertia calculated from weight and the center of
gravity position.
However, the setting is required when the moment of inertia of the tool is large (as a rough
guide, the tool is considered to be large when the tool size is about more than 2-times the dis-
tance between the flange and the center of gravity).
The size of the tool is not too big.
Setting the moment of inertia at center
of gravity is not necessary.
Rough value of the moment of inertia at the center of gravity can be calculated by the follow-
ing methods.
- Method to approximate the entire tool in hexahedron or cylinder.
- Method to calculate from each weight and center of gravity position of plural mass.
Refer to the following setting examples for details.
The size of the tool is big.
Setting the moment of inertia at center
of gravity is necessary.
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