Motoman PX2750, Manual

Page: 399 / 611

3.11 ARM Control
3-54
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Tool Load Information
Tool load information includes weight, a center of gravity position, and moment of inertia at
the center of gravity of the tool installed at the flange. These are registered in the tool file.
"
How to Calculate Tool Load Information
Weight: W (Unit:kg)
The total weight of the installing tool is set.
Set a little large value though it does not care by a rough value. Rase to a unit in each 0.5 to
1kg for small or middle robot and rase to a unit in each 1 to 5kg for large robot.
Center of gravity: xg, yg, zg (Unit: mm)
The center of gravity position of the installed tool is set as the position in the flange coordi-
nates.
It does not care by setting a rough value because it is usually difficult to get a strict center of
gravity position. 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
2
)
It is an moment of inertia of the tool at the center of gravity position.
The value is calculated around each axis of the coordinates which is in parallel to the flange
coordinates and whichever original position is the center of gravity position of the tool.
Set a large value though it does not care by a rough 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 need not usually set because
this data is small enough to the moment of inertia calculated from weight and the center of
gravity position.
Only when the moment of inertia of the tool is large (The size of the tool is, as a standard, in
* Flange Coodinates
XF: It is a direction right above when T axis
is 0 pulse position and the flange surface
of the manipulator turned to the front.
YF: Y axis led by XF,ZF
ZF: Perpendicular direction from flange surface
X F
Z F
Y F
XF'
ZF'
YF'
Center of Gravity Position
( Xg, Yg, Zg )
Iy
Iz
Ix
Inertia Moment around Center of Gravity
Ix, Iy, Iz
Weight:W