Nonquadratic ${{cal H}}_\infty$ Stabilization Conditions for Observer-Based T–S Fuzzy Control Systems

This paper investigates the nonquadratic output-feedback stabilization problem for nonlinear systems in Takagi-Sugeno´s (T-S) form. To achieve improved performance in the H_∞ sense, this paper provides two kinds of relaxation techniques: one for the case where all premise variables are measurable and one for the case where the premise variables are immeasurable. In particular, the emphasis of the second technique is the use of estimated premise variables for nonquadratic Lyapunov functions.