Manual, FT Sensor, Ethernet Axia
Document #9610-05-Ethernet Axia-05
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12.6 Reducing Noise
12.6.1 Mechanical Vibration
In many cases, perceived noise is actually a real fluctuation of force and/or torque, caused by
vibrations in the tooling or the robot arm. The Ethernet Axia sensor offers digital low-pass filters
that can dampen frequencies above a certain threshold. If digital low-pass filters are insufficient, a
digital filter may be added to the application software.
12.6.2 Electrical Interference
To reduce the effects of electrical noise on the sensor, do the following:
•
If interference by motors or other noise-generating equipment is observed, check the
sensor’s ground connections.
•
If sufficient grounding is not possible or does not reduce noise, consider using the sensor’s
digital low-pass filters.
•
Verify the power supply is Class 1, which has an earth ground connection.
12.7 Detecting Sensitivity Changes
Sensitivity checking of the sensor can also be used to measure the Ethernet Axia sensor’s health. Apply
known loads to the sensor and verifying the system output matches the known loads. For example, a sensor
mounted to a robot arm may have an end-effector attached to it. Use the following process to set a sensitivity
value:
1. If the end-effector has moving parts, they must be moved in a known position.
a. Place the robot arm in an orientation that allows the gravity load from the end-effector to exert load
on many sensor output axes.
2.
Record the output readings.
3.
Position the robot arm to apply another load, this time causing the outputs to move far from the earlier
readings.
4.
Record the second set of output readings.
5.
Find the differences from the first and second set of readings.
6.
Use the differences as a sensitivity value.
Even if the sensitivity values vary from sample set to sample set, these values can be used to detect gross
errors. Either the resolved outputs or the raw sensor voltages may be used (the same must be used for all
steps of this process).