Control and Monitoring of pH process using Fuzzy Based Controller

Abstract

In today scenario Industries use different types of process variables and parameters for measurement. Among that pH is the most important parameter. These pH measurements are prominent in the industries like food & beverage, power plant, paper industries, paramedical industries etc. The smaller change in pH (amount of acid added, base solution and time) will lead to tedious effects in the process. The control of the pH process is also non-linear in nature and maintaining the pH value in the process is difficult for the desired transient response. In order to reduce problems fuzzy based system was designed and it is efficient than conventional integral controllers. Keywords: Control of pH process, Fuzzy logic, MATLAB. INTRODUCTION Control of the pH neutralization process plays an important role in different chemical plants, such as chemical and biological reaction, waste water treatment, electrochemistry and precipitation plants, production of pharmaceuticals, fermentation, and food production such as in vegetable oil refining. The technology used within the process industries has changed rapidly in recent years as plant processes have become more and more complex. These changes are due to the increasing need for better product quality and requirements for the reduction of operating costs, including those associated with energy usage. Another important factor that contributes to the development of process industry technology arises from environmental legislation which not only puts significant demands on the process industries but is also constantly being revised. It is a known fact that a pH process plant is very difficult to model and control. It is often difficult to achieve a high performance and robust pH control due to their time-varying and severe nonlinear characteristics. Hence pH control is often considered a bench mark for new models and control strategies. As a result, significant new constrains have emerged which reflect directly on plant process technology. Besides, sensors and actuators applied in industrial plants are devices which contribute with nonlinearities such as dead-zones, hysteresis and backlash. In order to overcome this issue, several linear control techniques have been used in nonlinear plants.