How to do system identification with LabVIEW?

[allendavid]

Hi,everybody.

I'm trying to make an identification experiment in lab. An incremental encoder is installed on a gear  which is driven by a motor.

And the output data is collected by DAQ system. Now I want to use  Pseudo-Random Binary Sequence  as input stimulus signal.

How to make it with LabVIEW? Above all, how to impose the PRBS on the system? I don't know if I need some other hardware to stimulate system with PRBS or not.

I hope somebody can help me. THANKS! 

[Dennis_Knutson]

Check the posting at http://forums.ni.com/ni/board/message?board.id=170&message.id=67805&query.id=0#M67805

[allendavid]

Where are MLS Sequence Waveform.vi (outputs a waveform) and Binary MLS.vi (outputs an array)?
If PRBS is generated by LabVIEW, how to output to the hardware? How to implement it as a system input?

Thanks!

[Dennis_Knutson]

If your search didn't turn them up, then you probably have the base package of LabVIEW and the functions are not included. The search function is at the top of the functions palette.

You can use either function provide data to a DAQ output. If you want to use an analog output, you just have to wire the waveform to a DAQmx Write. Look at any of the shipping examples for DAQ output. Most of them use waveforms such as a sine wave but it doesn't matter. Waveform data is waveform data.

[allendavid]

Thank you, you're a real veteran!

I have a 6024E board. If I  want to put the PRBS data on a motor, do I need some additional DAC component? I'm a real rookie.

[Dennis_Knutson]

The 6024 has 2 analog outputs.

[allendavid]

If I use the 2 analog output of 6024E, which kind of motor shall I choose, DC or AC?

[allendavid]

If I use the 2 analog output of 6024E, which kind of motor shall I choose, DC or AC? Is it easier to control DC than AC?

[Dennis_Knutson]

I'm not experienced in motor control. You should post this as a new question. There's a motor control board.