Control design of a coupled-tank apparatus

Abstract

Modeling and designing a suitable controller for a process plays a crucial role in

deciding the efficiency c;lnd safety of process in industries. In this dissertation, coupled

tank apparatus is used to model a multivariable level process and the process model thus

obtained is used to study the interaction analysis so as to design a controller for the

process. The process model is identified by means of an open loop step test and FirstOrder-

Plus-Time-Delay (FOPTD) model parameters are determined using various

parameter identification methods. The 'Best fit' process parameter model obtained is

used for interaction analysis using steady state relative gain array. The condition number

for the multivariable coupled tank process was calculated to check for sensitivity issues.

Depending on the interaction analysis, the multivariable coupled-tank was decoupled

into 2 SISO loops (Single Input Single Output). Different controller designs based on the

model of the process were implemented. The results obtained were investigated to select

a suitable control design for coupled tank apparatus.