Motion Control

[sadiah]

Hi,

I have been using PCI 7344 to control 3 ac servo motors. Everythings worked fine. xyx axes motion.

Since I want to compare the performance between PID and fuzzy control, I've bought Compact fieldpoint and Labview RT and all necessary equipment to realise the application. Please share with me on any helpful info eg: programming, things to caution, wiring etc

TQ

SADIAH

[Prashanth]

Hi Sadiah,

Below are some links that may be helpful to you:

PID Theory Explained
https://www.ni.com/en/shop/labview/pid-theory-explained.html

PID Control Toolset User Manual

https://www.ni.com/docs/en-US/bundle/372192d/resource/372192d.pdf

Regards,
Prashanth

[Jochen]

Sadiah,

please note that FieldPoint is much slower than a PCI-7344. While the 7344 can run PID cycles with up to 16 kHz FieldPoint will perform PID loops with about 100 Hz. To research general control behavior this might be ok but if you want to use FieldPoint in a real-world application you should figure out if the PID loop is fast enough for you.

If you need faster PID loop rates with the same or even more flexibility than FieldPoint please have a look at our compact RIO products.

Bes regards,

Jochen Klier
National Instruments Germany

[mfi.edu.my]

Dear Joachen,

I have been trying to run my servomotor system+load using softmotion. The motor runs but jerking. I check the program available for motion loop but could not figure out the problem.  Is this also being the reason why I am not getting the transfer function when determining the system identification.

TQ

SADIAH

[Jasper S]

Sadiah,

Does your motor constantly "jerk" or do you just see this behavior when it starts or stops a move?  Are you moving in a straight line, contour, doing a blend?  Have you set up the timing correctly?  You will need to configure your SoftMotion timing settings to correlate with the rates that both your RT and FPGA VIs are running. 

Finally, you may want to make sure your PID rates have been set up correctly, as discussed earlier in this post.

Regards,

Jasper S

[mfi.edu.my]

Another from me regarding the system identification of the plant. I did the open loop test, and the results were excellence. But when it come to system identification phase, adjusting the model does not bring out good comaprison between simulated and plot values.

What are the best model for my plant; should it be state space, ARX, ARMAX etc. Need suggestion frm whomever hasexperience with system identification.

TQ.

SADIAH