Fractional Standalone Backstepping Control for Nonlinear Continuous Stirred Tank Reactor
Deep Mukherjee, G. Lloyds Raja, Palash Kundu, Apurba Ghosh
Abstract
ABSTRACT Controlling the molar concentration in a chemical reactor is a challenging task in the presence of noise and disturbance. Contrary to the reported works based on augmented method, this work proposes a novel fractional order standalone backstepping rule as a feasible alternative to stabilize the concentration of a nonlinear continuous stirred tank reactor process. The novel indirect biquadratic equiripple approximation technique is suggested to realize the behavior of fractional order element in the proposed rule with a suitable integer order process. The proposed approximation method is further modified by an additional exact phase approach to enhance the behavior of fractional order element. A comprehensive simulation study on both frequency and time domain platforms is carried out to establish the suitable fractional order in the proposed law. Closed‐loop performance and control efforts obtained through simulation studies vindicate that the proposed technique outperforms existing control strategies without unnecessary overshoots and yields relatively smooth control action in the presence of noise and disturbance. By abruptly altering the system settings, the robust stability investigation of the proposed rule is also carried out in the presence of load disturbance and noise. This proposed technique offers greater accuracy by resulting in less integral errors and total variation of input control action in both nominal and perturbed circumstances.