Manual, F/T Sensor, Ethernet Axia
Document #9610-05-Ethernet Axia-09
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4.6 Bias
Biasing is useful for eliminating the effects of gravity (tool weight) or other acting forces. When the bias
function is used, the software collects data for the forces and torques that are currently acting on the sensor
and use these readings as a reference for future readings. Future readings will have this reference subtracted
from them before they are transmitted. Bias may also be referred to as “zero out” or “tare” the sensor.
4.7 Tool Transformation
By default, the forces and torques are reported with respect to a point of origin on the sensor that is set by
ATI. Refer to the drawing in
Section 16.1—Axia80 Force/Torque Sensor 9230-05-1543
for the sensor’s point
of origin. The tool transformation function allows measurement of the forces and torques at a reference point
other than the sensor’s point of origin.
CAUTION:
If the customer sets a reference point that is at the same location to which
a force is applied, there will be no report of a torque applied to the sensor. As a result,
the sensor could be overloaded (refer to
Section 4.7.1—Avoid Overloading the Sensor
). Therefore, when evaluating overloading conditions, use
the sensor’s point of origin as the reference point.
The user defines a reference point by inputting a parameter set that is a series of (3) displacements (D
x
\ D
y
\
D
z
) and (3) rotations (R
x
\ R
y
\ R
z
), for example:
D
x
= -97.3 mm D
y
= 46.1 mm D
z
= 201.82 mm R
x
= +90° rotation R
y
= +180° rotation R
z
= 0° rotation
If zeros are entered for any of the parameter set values, the tool transformation is not performed for that
particular parameter. Entering zero for all of the parameters, turns the tool transformation feature off. Once a
new parameter set is entered and saved, previously entered parameter sets are no longer in effect.
Once a user enters a parameter set, the displacements are performed first. The displacements of the user
reference frame of origin from the sensor point of origin is shown in the following figure. In this figure, the
user reference frame of origin has not yet rotated relative to the sensor point of origin.
Figure 4.6—Tool Transformation : Distances
The robot side
of the sensor.
The tool side of
the sensor.
Sensing reference frame origin
that is set by the customer.
Customer tooling
X+
Y+
X+ Axis
before rotation.
Y+ Axis
before rotation.
Z+ Axis
before rotation.
Z+
201.82 mm
46.1 mm
97.3 mm