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The main theme of this paper is to present robust fuzzy controllers for a class of discrete fuzzy bilinear systems. First, the parallel distributed compensation method is utilized to design a fuzzy controller, which ensures the robust asymptotic stability of the closed-loop system and guarantees an H[infinity] normbound constraint on disturbance attenuation for all admissible uncertainties. Second, based on the Schur complement and some variable transformations, the stability conditions of the overall fuzzy control system are formulated by linear matrix inequalities. Finally, the validity and applicability of the proposed schemes are demonstrated by a numerical simulation and the Van de Vusse example. Index Terms--Discrete fuzzy bilinear system (DFBS), linear matrix inequality (LMI), parallel distributed compensation (PDC), robust H[infinity] control, Takagi-Sugeno (T-S) fuzzy model, Van de Vusse example.

This brief considers the problem of stabilization of uncertain singularly perturbed systems with pole-placement constraints by using [H.sup.[infinity]] dynamic output feedback design. Based on the Lyapunov stability theorem and the tool of linear matrix inequality (LMI), we solve dynamic output feedback gain matrices and a set of common positive-definite matrices, and then some sufficient conditions are derived to stabilize the singularly perturbed systems with parametric uncertainties. Moreover, the developed [H.sup.[infinity]] criterion guarantees that the influence of external disturbance is as small as possible and the poles of the closed-loop system are all located inside the LMI stability region. By the guaranteed [epsilon]-bound issue, the proposed scheme can stabilize the systems for all [epsilon] [member of] (0, [epsilon] *). A circuit system is given to illustrate the validity of the proposed schemes. Index Terms--Dynamic output feedback design, linear matrix inequality (LMI), Lyapunov stability theorem, singular perturbation systems.

In this paper, the concepts of car maneuvers, fuzzy logic control (FLC), and sensor-based behaviors are merged to implement the human-like driving skills by an autonomous car-like mobile robot (CLMR). Four kinds of FLCs, fuzzy wall-following control, fuzzy corner control, fuzzy garage-parking control, and fuzzy parallel-parking control, are synthesized to accomplish the autonomous fuzzy behavior control (AFBC). Computer simulation results illustrate the effectiveness of the proposed control schemes. The setup of the CLMR is provided, where the implementation of the AFBC on a field-programmable gate array chip is also addressed. Finally, the real-time implementation experiments of the CLMR in the test ground demonstrate the feasibility in practical car maneuvers. Index Terms--Autonomous fuzzy behavior control (AFBC), car-like mobile robot (CLMR), field-programmable gate array (FPGA), fuzzy logic control (FLC), garage parking, parallel parking, real-time implementation.

This paper is devoted to design and implement a car-like mobile robot (CLMR) that possesses autonomous garage-parking and parallel-parking capability by using real-time image processing. For fuzzy garage-parking control (FGPC) and fuzzy parallel-parking control (FPPC), feasible reference trajectories are provided for the fuzzy logic controller to maneuver the steering angle of the CLMR. We propose two FGPC methods and two FPPC methods to back-drive or head-in the CLMR to the garage and the parking lot, respectively. Simulation results illustrate the effectiveness of the developed schemes. The overall experimental setup of the parking system developed in this paper is composed of a host computer, a communication module, a CLMR, and a vision system. Finally, the image-based real-time implementation experiments of the CLMR demonstrate the feasibility and effectiveness of the proposed schemes. Index Terms--Car-like mobile robot, fuzzy logic control, garage parking, parallel parking, real-time implementation.

The stability and D-stability problems of the multiparameter singularly perturbed discrete-time systems and its reduced subsystems are explored in this paper. The critical stability criterion of the discrete system is adopted to examine the stability bounds. A three-step algorithm is proposed to determine an upper bound of the norm of the multiparameter vector [epsilon] = [[[epsilon].sub.1] [[epsilon].sub.2] ... [[epsilon].sub.N].sup.T]. A numerical example is given to compare the new results with those of previous literature. Index Terms--Singular perturbation parameter, singularly perturbed discrete-time systems, stability bound, state-space approach.

In this paper, based on Lyapunov stability theorem, matrix measure, and norm inequalities, a new approach for the robust stability of perturbed systems with a class of noncommensurate time delays is presented. Two classes of linear parametric perturbations are treated: (1) unstructured and (2) highly structured perturbations. Several concise sufficient conditions, delay-dependent or delay-independent, are proposed to guarantee the asymptotic stability and positive stability degree of the perturbed multiple time-delay systems. Finally, two numerical examples are given to demonstrate the applications of these quantitative results.