Abolhassan Razminia

This study presents a black-box identification and a self-tuning control design of a nonlinear continuously stirred tank reactor (CSTR). Analyzing and controlling the CSTR is a challenging topic because of its highly nonlinear dynamics and its sensitivity, which, in turn, requires a high-performance control design. The data set used in the identification is collected from the nonlinear dynamical equations of the CSTR in the presence of white and colored noises for considering realistic conditions. Then, linear model structures are selected, and by employing the online and offline estimation methods, the best representation of the CSTR is determined based on a fitness index. By employing the results of the online identification algorithms, a self-tuning proportional–integral–derivative (PID) controller is designed which provides an ability to control the CSTR in the presence of unwanted signals (i.e., noise and disturbance) and variations in system dynamics by considering several tuning parameters including forgetting factor and suitable initial values. The performance of the proposed approach is compared with several works in the literature, reflecting the superiority of the presented technique.