Observer-based adaptive fuzzy control of a class of nonlinear systems with unknown symmetric nonlinear dead zone input

• We establish a class of nonlinear systems with unknown symmetric nonlinear dead-zone input.
• The nonlinear symmetric dead-zone model is linearized by the using of the differential mean value theorem.
• The observer-based adaptive fuzzy control design overcomes the influence of dead-zone input on the system stability.
• The stability of the closed-loop system is proven through the Lyapunov method.

In this study, we propose an observer-based adaptive fuzzy controller for a class of nonlinear systems with unknown symmetric nonlinear dead zone input. First, we establish the nonlinear symmetric dead zone model, which is then transformed into a linear symmetric dead zone model for processing. Next, we apply the observer-based adaptive fuzzy control method to the transformed model. The stability of the closed-loop system is proved using the Lyapunov function analysis method. Our simulation results demonstrate that the proposed method achieves the desired performance.