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For the output feedback control problem of a T‐S fuzzy system, an H∞ observer‐controller synthesis method is proposed. First, with parallel distributed compensation fuzzy observer and cont...

The problems of observer-based feedback control and stability analysis for a T-S fuzzy system are investigated in this paper. Based on system output variable, a membership function dependent observer and a controller subject to observer errors are constructed to estimate the unknown system state and establish the closed-loop feedback control system. The derived stability criteria, which is not numerically solvable, is converted to a solvable optimization problem. An improved membership function dependent approach is proposed to reduce the conservativeness. The approximated values of membership functions and their derivatives are calculated based on the proposed piecewise-function method. Then, a piecewise decaying rate setting technique is presented to adjust the error convergent speed. A three-rule fuzzy system stability analysis example is given to show the conservativeness reduction effects, while an inverted pendulum cart control process is used to show the effectiveness of the proposed observer-based control scheme.