Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

help to find control system element equation

help to find control system element equation

help to find control system element equation

hello everybody,

i am looking for a little help because i am so confuse. i have a second order transfer function system which i need to model in sumulink. i am making a temperature pid controller. i am using a heating element which is the process. how can i find out the process function/equation? i know how to work out equation from a electrical circuit, but i don't know how to work out the equation for a heating element.

please tell me if it doesn't make any seance to you.


RE: help to find control system element equation

You don't need to. The feedback can be just the output of the sensor. This should be just fine.
If you really want to model the temp sensor dynamics you can use a first order differential equation like
The solution is a natural exponential function.
Although, many sensors may behave differently.  

Fe (IronX32)

RE: help to find control system element equation

thanks for the replay. if i dont know what is my process function how can i find out my 2nd order transfer function?

what i came up with to use the phisical process to see the feedback output. make a graph and use those value to do the transfer function, am i right?

one more thing my input is duty cycle and set point is degree C. how are they related? i can use labview to tune and make the control system in no time, but i need to understand how come the input and set point is two different type, and how can i explain it.

RE: help to find control system element equation

Looks like a homework problem, read the site rules!

Mark Hutton


Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close