Hi all,

I have an first order plus time delay system with

The system is defined as

There is some calculation given by ZN tuning method for FOPDT system

where

I had work out for the Kc and Ti and found that

Gc is given that

so Gc=0.1411*[1+(1/0.2s)] = 0.1441*[(0.2s+1)/0.2s]

but once i put this Gc into my system by Simulink, my wave seen oscillated very much. Can anyone tell me what i had done wrong and which parameter should i tunning ? Can i tune the Kc from 0.1411 to another value like 0.7?

Thankyou very much.

I have an first order plus time delay system with

**K=58.46**,**T(time constant)=0.55s,****Td(Time delay)=0.06s**and i had some trouble in design this PI Controller by using Ziegler Nichols tuning method.The system is defined as

**G=58.46/(0.55*s+1)*exp(-0.06*s)**There is some calculation given by ZN tuning method for FOPDT system

where

**Kc=0.9*T/(K*Td)**and**Ti=3.33*Td**I had work out for the Kc and Ti and found that

**Kc**=0.9*0.55/(58.46*0.06)=**0.1411****Ti**=3.33*(0.06)=**0.2**

Gc is given that

**Kc*[1+(1/Ti*s)]**,so Gc=0.1411*[1+(1/0.2s)] = 0.1441*[(0.2s+1)/0.2s]

but once i put this Gc into my system by Simulink, my wave seen oscillated very much. Can anyone tell me what i had done wrong and which parameter should i tunning ? Can i tune the Kc from 0.1411 to another value like 0.7?

Thankyou very much.

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