Optimal H∞-Based Linear-Quadratic Regulator Tracking Control for Discrete-Time Takagi–Sugeno Fuzzy Systems With Preview Actions

This paper investigates the optimal tracking control problem for discrete-time Takagi–Sugeno (T–S) systems. The control signal has three components: preview control for the previewable reference signal, integral control for the tracking error, and the state-feedback control for the plant. The optimization objective is a quadratic form of the tracking error and the control signal. By using the augmentation technique, the tracking controller design problem is converted into a design problem of the state-feedback controllers for augmented T–S fuzzy systems. The quadratic optimization objective is equivalent to the two-norm (in fact, the square of the two-norm) of a controlled output. Assuming that the external inputs of the augmented systems are l2 bounded, the H∞ performance index is employed to investigate and optimize the controller design. The controller gains can be obtained by solving a sequence of linear matrix inequalities (LMIs). An example on electromechanical system shows the efficacy of the proposed design method.