Understanding Closed-Loop Multivariable Transfer Function Identification

Understanding Closed-Loop Multivariable Transfer Function Identification Model Predictive Control (MPC) technology is widely and commonly used in refinery, petrochemical, and manufacturing plants. As a matter of fact, MPC has drawn interest from several other industries as well.

Dynamic models play a vital role in Model Predictive Technology (MPC). The models are used as MPC controllers. One of the most important things about MPC is; closed-loop multivariable identification. Modeling & identification is an important part of MPC technology.

What is closed-loop identification?

Closed-loop identification is defined by the process that’s identified using data collected from closed-loop tests. Here, the underlying process remains fully or partly under feedback control. The closed-loop identification can be seen from both the operational point of view and the control theoretical point of view.

Model Predictive Control (MPC) application is very challenging and beneficial at the same time.

Depending on the class of the process, closed-loop identification processes can be characterized as follows   

Large scale and complex Slow & high-level disturbances Slow dominant dynamics Local non-linearity

Why identification is an important part of MPC technology?

A good identification test plays a crucial role in the successful identification of the MPC process. Now, industries that rely on MPC applications use a series of openloop and single-variable step tests. Usually, the tests are executed manually.

Because this test method offers several benefits, this test method is practiced in several industries. Although there are certain problems involved in the test processes, the problems can be solved easily by using automatic multivariable tests.

The advantages of closed-loop test conduction are  

It plays a great part in reducing the disturbance while processing operation and eliminating product off-specification.

It allows the operators to carry out the identification test task easily and efficiently.

A closed-loop test lessens the numbers of errors.

One important thing about closed-loop identification you should know about is the choice of the model structure. It depends on three conflict issues. The issues are  

The consistency of the model The compactness level of the model The numerical complexity of the model (in parameter estimation)

Want to know more about closed-loop multivariable identification? Explore the website https://www.picontrolsolutions.com/products/columbo/ of Pi Control Solutions to see what we can do for you. We extend our services to different varieties of industries. If you want to collaborate with us, feel free to get connected to our team.