LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

Real time PID

Hi everyone!

I developed a PID control using labview and it's working fine!

Now I need to get some values like the settling time of the control but I don't know how to do it properly and accurately!

I will adjust the VI I've developed.

navarro08_0-1617702482920.png

 

I am plotting the two signal ( set point and the signal I want to control).

 

Does somebody know how I can get this time?

Thank you very much!

 

0 Kudos
Message 1 of 4
(129 Views)

Hi navarro,

 

can you provide example data?

Or atleast an image showing those plots so we can provide comments?

 


@navarro08 wrote:

Now I need to get some values like the settling time of the control but I don't know how to do it properly and accurately!

I am plotting the two signal ( set point and the signal I want to control).

Does somebody know how I can get this time?


Do you know the signal/control theory to know how to determine settling times?

Can't you use that knowledge on your measurement data?

Best regards,
GerdW

using LV2011SP1 + LV2017 (+LV2020 sometimes) on Win10+cRIO
0 Kudos
Message 2 of 4
(68 Views)

Thanks for answering me!

Here you can see the graph I am getting.

 

navarro08_0-1617765835163.png

 

The thing is , I need to get the time it takes to become stable. I don't trust the time of this graph. I think the other modules are takin too much resource.

 

0 Kudos
Message 3 of 4
(56 Views)

Hi navarro,

 


@navarro08 wrote:

The thing is , I need to get the time it takes to become stable. I don't trust the time of this graph. I think the other modules are takin too much resource.


When you don't trust your own VI then you should improve it!

I would start with replacing all those ExpressVIs (mostly DAQAssistents) by plain DAQmx functions! This will greatly improve the performance of the VI.

Then you should switch over to hardware-timed DAQmx tasks to improve timing even more: no need to run a loop with a 10ms timer when your hardware can ensure a 100Hz samplerate much more precisely!

 

Btw. you also need to define "become stable": there is some fluctuation in your plot all the time…

Best regards,
GerdW

using LV2011SP1 + LV2017 (+LV2020 sometimes) on Win10+cRIO
0 Kudos
Message 4 of 4
(28 Views)