Real-Time Measurement and Control

cancel
Showing results for 
Search instead for 
Did you mean: 

Force and Torque on Sensor Always Register in the Z Force axis

Hi all,

 

I'm running into a really weird problem trying to sample and calibrate data from an ATI F/T sensor with a cRIO. No matter how I press on or torque the sensor, the Z- or Z+ channels register. I have followed ATI's guide of sampling 12 signals (6 values and 6 references), subtracting the references from the values, and multiplying the calibration matrix specific to my sensor by the values.

 

I have checked pin configurations, unit tested all parts of my code, and tried manually calculating results to check my sanity. I was thinking it might be a pin configuration issue, but all my references are around the same value and if the pins were switched, why would Z- be registered all the time? I am extremely lost on what to do.

 

I have reached out to ATI and they suggested that I check my pins (checked and rechecked), use their example software (all configured for a DAQ and not a cRIO), and try their demo software (again not compatible with a cRIO). I was wondering if it's my LabView code and not the physical device setup that is the problem?

 

Problem Details:

  • Applying force or torque on the F/T Sensor in any way except torque in the X+ and Y+ direction results in Z- force being registered.
  • Applying torque in the X+ and Y+ directions results in Z+ force being registered.
  • Flipping the sensor upside down and applying force in the Z direction still results in Z- force being registered.

 

Setup Information:

  • ATI Mini85 F/T connected to ATI FTIFPS1 amplifier.
  • ATI FTIFPS1 amplifier connected via a 9105-C-PS-D37-3.5 cable to a NI 9205 ADC.
  • NI 9205 in Mod3 on a cRIO-9040.
  • cRIO-9040 connected to PC via ethernet.
  • Programmed in LabView 2023 Q3 (64-bit)
0 Kudos
Message 1 of 2
(132 Views)

If you want to eliminate any problem with your code, can you look at the raw AI values on the NI-9205 in NI-MAX. Or do you have the capability to measure the voltages directly without having them connected to the NI-9205. The only other quick thing I would suggest is making sure you are using the correct wiring, differential or single-ended, for the amplifier output and that the grounding is all correct between the power of the F/T and its amplifier and the cRIO. There is a good guide to field wiring if that is something you are not familiar with:
https://www.ni.com/en/shop/data-acquisition/measurement-fundamentals/field-wiring-and-noise-consider...

Consultant Control Engineer
www-isc-ltd.com
0 Kudos
Message 2 of 2
(112 Views)