Output tracking for nonlinear discrete-time systems via fuzzy control approach.

The output tracking control problem is investigated for a class of nonlinear discrete-time systems via Takagi–Sugeno (T–S) fuzzy observer-based control approach. A delayed fuzzy observer is firstly established to estimate state variables and premise variables. Then, a target state is built to convert the output tracking problem into the stabilization problem of a tracking error system. As a result, we can use the approaches for stabilization problems to realize the output tracking. Finally, a new delayed nonquadratic Lyapunov function is introduced to design controller gains and observer gains separately. Two practical examples, subsuming PWM buck converter and mass–spring–damper system, are considered to show the effectiveness of our results. A numerical example demonstrates the superiority of the proposed method. [ABSTRACT FROM AUTHOR]