Development of hybrid intelligent fractional order control for Non Linear interacting tank system

Abstract

The control of liquid level in the coupled spherical tank system is a challenging benchmark control problem. The dynamics is widely related to many real systems such as distillation column, boiler process, oil refineries and many more. Most of the chemical processes are non-linear in nature. It is a most challenging benchmark control problem owing to its non-linear and non-minimum phase characteristics. Several researchers studied and investigated about reducing the non-linearity problem and their approaches provide better result. But, few works have been reported for validating the developed control strategies through the experimental setup. Thus, there lies a good opportunity to develop some advanced controllers and to implement them in real-time on the experimental set-up of a non-linear interacting coupled spherical tank system in the laboratory. newlineThis thesis provides the control of non-linear interacting coupled spherical tank system with detailed information about the process involved along with its hardware setup. The objective of the present research is to maintain the water level at the desired set point value and also simultaneously ensure robust performances, when there is a load disturbance. Based on the mathematical model, control algorithms are developed in order to maintain constant liquid levels in the presence of disturbances which is arising due to sudden opening of the valve in the tanks. Conventional control techniques are not satisfactory and increases complexity in its control design. newlineInitially, for regulating desired liquid level in both the tanks, PI (Proportional Integral) controller has been designed and implemented in real-time. Satisfactory response in terms of rise time, settling time and peak overshoot are not achieved with the conventional controller due to the high non-linear nature of the process. newline