what do the variable P,I and D mean in PID(z) in simulink?

Hello, As you saw in my question, do P.I and D means Ku(ultimate gain),Ti and Td respectively when using the PID from simulink? thanks

[Guillaume]

We could turn back the question back on you and ask what do the variable Ku, Ti and Td mean for you?

They're obviously the proportional, integral and derivative constant respectively. What they mean exactly is completely documented in the help.

Answer 1

[SimTec]

Hello Birdman and Thank you so much for your help. So what I understood is that I have to write the value in the PID(z) in simulink as showed in the pictures.is it correct!

Answer 2

[Jim Riggs]

See the link to help in Guillaume's comment:

 Proportional
 Integral
 Differential

Answer 3

[SimTec]

Sorry, My question was wrong. I know those what they mean but my question when it comes to tuning a PID. in the PID(z) controller, I see P,I and D, using Ziegler Nichols, SHould I put the value calculated like P=Ku,I=Ti and D=Td or P=Kp,I=Ki and D=Kd? thanks

Answer 4

[Birdman]

This question can be answered in different aspects but let me start from explaining them in this way:

If you are going to write IDEAL(not reasonable in this form) PID structure, you may write it as follows:

PID(s)=(Kd*s^2+Kp*s+Ki)/s

and also, a second form, which is also widely used IDEAL(not reasonable in this form), is as follows:

PID(s)=Ku*(1+(1/Ti*s)+(Td*s))

Which one to use is totally up to the user. In the first form, you can think of each term as independent because every term has its gain and by setting each of them, you design a PID. In second form, you have a global gain for your PID and time constants Ti and Td decides the weight of I and D term in your controller respectively.

[Birdman]

Answer to

Hello Birdman and Thank you so much for your help. So what I understood is that I have to write the value in the PID(z) in simulink as showed in the pictures.is it correct!

See the attached figures, for both ideal and parallel PID, the thing that I explained in my answer.