Finite-time Sliding Mode Control for Continuous Stirred Tank Reactor Based on Disturbance Observer

This paper aims to investigate the robust control problem of Continuously Stirred Tank Reactors (CSTR). A CSTR is one of the most essential pieces of equipment in chemical processes, whose effects of highly nonlinear dynamic and external disturbances make it very difficult to be controlled. Firstly, a novel finite-time sliding mode control is introduced that eliminates disturbance effects and ensures finite-time tracking. Secondly, to better compensate for disturbances and to improve controller performance, a finite-time disturbance observer is developed. Finally, an adaptive robust control method is introduced based on the proposed sliding mode control and the disturbance observer. Stability analysis is performed to investigate the finite-time tracking of the closed-loop system under the proposed controllers. Besides, to enhance the performance of the proposed controllers, the design parameters are tuned by the genetic optimization algorithm. Simulation results are produced to confirm the efficiency of the proposed methods in terms of tracking errors and convergence rates. The proposed finite-time sliding mode control and the adaptive finite-time sliding mode control with settling times of 1.73s and 1.71s as well as IAE of 0.509 and 0.4843, respectively, showed more desirable performance than other controllers.