Adaptive Fuzzy Fault-Tolerant Control for CSTR With State Constraints Dependent on Temperature and Concentration

The indispensable experimental equipment of the continuous stirred tank reactor (CSTR) is crucial in chemical production processes. This paper presents a novel adaptive state-dependent constraint control method for nonlinear CSTR system. The CSTR system is transformed into the nonlinear system with a pure feedback structure begins with the mean value theorem. Subsequently, the Fuzzy logic systems (FLS) is used to approximate unknown dynamics. Reactant concentration and mixture temperature are crucial variables in CSTR system. When these variables surpass the specified constraints, it can lead to a decrease in product quality and yield. The constraint boundaries considered in this paper are dependent on both state and time. Therefore, the time-varying asymmetric Barrier Lyapunov Function (BLF) is proposed to deal with state-dependent constraints. Additionally, the actuator fault is resolved in this paper, by considering fault-tolerant control strategy. Lyapunov stability analysis shows that all signals in a closed-loop system are bounded. Finally, the effectiveness of the control scheme is verified by the simulation of CSTR system.