How and where to use PID controller?

[hiyan]

i wantto ask about PID controllaer where i use p wheere and which sitvation i use I and D ?2nd if i wantto controll motor speed through PID in which manner i mean where i use integral where i use d and p?

 

[epp]

Re: PID

P-proportional
It is used adjust response of your controller. If too big you will have large overshoot and oscillations in controller response (motor speed etc.). First you adjust this parameter.
I-integral
It is used to minimize steady state error. It should be small othervise you will cancel P part. This parameter is adjusted after tuninig of P part.
D-derivative
It is used to compensate large change of error (d(err)/dt). Usually one doesn't use it because it relies on data in "future". This paparemeter is tuned last.

 

[hiyan]

Re: PID

if i wantto controll MAchine speed like i wanna constant speed of machine which integral i will us e?

 

[epp]

Re: PID

Integrator is formed by an operational amplifier if you want to realise it in analog otherwise is digital. Try to do some serach in www. I found some good file about it but I cannot remember where I save it. When you make your controller you have to make it work then do fine tuning of your response by changing P and I term.

Regards.


P.S.
Please click helped.

 

[electronics_kumar]

Re: PID

i wantto ask about PID controllaer where i use p wheere and which sitvation i use I and D ?2nd if i wantto controll motor speed through PID in which manner i mean where i use integral where i use d and p?

I controller will reduce steady state error by increasing order of the system(also it will increase the number of zeros)
D controller will reduce overshoot by increasing damping of the system.....(it will also increase the number of zeros like I controller)

 

[hiyan]

Re: PID

Again question is which part of controller keep Motor speed constant ?




I ,p or D:?:

kindly explain me .thanks

 

[btbass]

PID

Have a look at Microchips website and application notes for motor control. Lots of examples and c code to implement constant speed. Normaly, a PI controller will do the trick.

 

[atc9443]

PID

Great sites to learn about PIDs

http://www.learncontrols.com
http://www.jashaw.com
also, PIDs with matlab and simulink tutorials:
**broken link removed**

 

[mobile-it]

Re: PID

Great sites to learn about PIDs

h**p://www.learncontrols.com
h**p://www.jashaw.com
also, PIDs with matlab and simulink tutorials:
h**p://www.library.cmu.edu/ctms/ctms/pid/pid.htm

I think the first link has to be: http://www.learncontrol.com

 

[atc9443]

PID

yea, forgive me about the mistake,
www.learncontrol.com is just a variant site from www.jashaw.com. So i suggest just going to www.jashaw.com