Control of Inverse Response Processes by Model Predictive Control (MPC)

Due to the presence of Right Half Plane (RHP) zeros in the system, inverse response processes becomes hard to be identified and controlled. It happens when two separate effects are taking place at the same time but in different direction. Although inverse response problem is not infrequent to occur in industry especially chemical process industry, not many researchers pay attention towards controlling and solving this problem. In this paper, the author aims to compare the performance of the Model Predictive Control (MPC), Proportional Integral Derivative (PID), and Simple Internal Model Control (SIMC) in producing satisfactory control output for inverse response processes. Under this main objective, the author specifies it into three sub objectives. The first one is to design a MPC, PID, and SIMC for typical inverse response process. The second one is to measure the performance of the various controllers for set-point tracking or servo problem and lastly to compare the performance of the designed controllers.
To ensure that all the objectives can be accomplished, proper methods need to be set and done throughout the progress of the project. To achieve objective 1, the author will make a proper selection on the type of controller to be used for this project and write the MATLAB coding for the selected controller, MPC, PID, and SIMC. It is crucial to identify the suitable methods and make a proper analysis on the performance of the controller. Three methods, Integral of Absolute Error (IAE), Integral of Squared Error (ISE), and Integral of Time-weighted Absolute Error (ITAE) have been proposed in order to analyse and measure the performance of the designed controller. These methods will be further elaborated in the research methodology part of this paper. And in the end, to attain last objective, the author will compare the results of measurements based on set-point tracking condition.
This project principally covers the simulation analysis and project design where the author will accomplish most of the task by using the MATLAB software during the course of this project. In end of this project, the author determines that MPC provides the quickest response compared to PID and SIMC controller other than producing satisfactory overall performance and is suitable to be used to control an inverse response process. Not only that this project can achieve its objective within time constraint, it is also feasible as the project is easily understood and the software that will be used to design the controller is fairly available.