Development of advanced control scheme for nonlinear process using soft computing techniques

Abstract

newline Industries have many units of operations, which may utilize reactors for different purposes. Continuous stirred tank reactor (CSTR) is widely used and has acquired an important role in process industries. It exhibits highly nonlinear dynamics and usually has ample operating ranges. In general reactors are either exothermic or endothermic. Most of the researchers focusing on the control of ideal CSTR models, but the proposed research work focus on designing the controllers for an irreversible, exothermic CSTR. Designing a controller for the process which exhibits a huge parameter variation is really a challenging task. The objective of this research work is to develop a single controller having the knowledge to address the complication of using PID controllers that are tuned for different operating points and to develop a suitable controller which should have an adaptive knowledge to function in all operating region and to have the ability to improve local searching capability by employing a soft computing technique. To fulfil the objectives of the proposed research, various works have been carried out at different levels. In the first phase of research work two different PID tuning rules are applied to the benchmark nonlinear CSTR process and analyzed the performance of the system. Both the servo and regulatory responses provided in the results clearly mentions that the IMC PID control method is capable to respond better than the empirically tuned PID in a dynamically varied set point profile. The gain margin and phase margin values are comparatively greater in IMC PID control, which ensured that the output response was smooth when compared to other method.