Using torque-sensor for servo control feedback loop

[Lysandros]

Dear NI-enthusiasts,

for a HiL application I am planning to use a brushless servo motor (around 1-2 kW rated power ) for generating a specific torque-load profile. For the torque-command, a PXI platform will be probably used. Most servo drives use the instantaneious motor current for estimating the generated torque. However, I would like to use an external torque sensor for closing the feedback loop, since I want to control the load at a point which is slightly offset to the servo rotor (amplitude & phase shift). Is this possible? Have similar cases been implemented with NI-hardware?

Best regards

L.A.

[Duffy2007]

Hello Lysandros89,

the question in this point is, how fast should the control loop run.

As an example, if you are using an EtherCat drive and a PXI controller you could run control loops with round about 1-2ms, depending on the system.

Another option is to use a cRIO with a 9514 modul and an addtional modul for your torque sensor, then you have the option to implement your own motion controller in the FPGA, but this make more effort for the programming part.

The easier way is to use a EtherCat drive and to drive slower on the part you want to inspect and implementing a control loop with the torque sensor in the RT part of the system.

Hope this helps a little bit with your decision.