Tianyou Chai

Fuzzy direct adaptive control for a class of nonlinear systems

A direct adaptive tracking control architecture is proposed for a class of continuous-time nonlinear dynamic systems, for which an explicit linear parameterization of the uncertainty in the dynamics is either unknown or impossible. The architecture employs fuzzy systems to approximate the optimal controller which is designed on the assumption that all the dynamics in the system are known, develops fuzzy sliding controller to compensate for the plant uncertainties, smooth the control signals and increase robustness. Global asymptotic stability is established in the Lyapunov sense, with the tracking errors converging to a neighborhood of zero. The simulation results verify the effectiveness of the proposed control algorithm.

Fuzzy adaptive control for a class of nonlinear systems

An adaptive tracking control architecture is proposed for a class of continuous-time nonlinear dynamic systems, for which an explicit linear parameterization of the uncertainty in the dynamic is either unknown or impossible. The architecture employs fuzzy systems to approximate nonlinear functions, uses fuzzy sliding controller to compensate for the plant uncertainties. Global asymptotic stability is established in the Lyapunov sense, with the tracking errors converging to a neighborhood of zero.

New approaches on H∞ control of T--S fuzzy systems with interval time-varying delay

An improvement in a method for transfecting a cell with a nucleic acid the improvement comprising contacting the cell with a liposomal transfection composition comprising the nucleic acid, sphingosine or a derivative thereof, having a protonable amino group in the sphingosine moiety, and at least one helper lipid.

Direct adaptive control and robust analysis for unknown multivariable nonlinear systems with fuzzy logic systems

In this paper, we are dealing with the problem of controlling an unknown nonlinear dynamical system modeled by fuzzy logic systems. In the ideal case of complete model matching, convergence of the state to zero plus boundedness of all signals in the closed loop system is ensured. Moreover, the robustness of the controller designed in the ideal case is given in the framework of singular perturbation theory.

FUZZY DIRECT ADAPTIVE CONTROL FOR A CLASS OF DECENTRALIZED NONLINEAR SYSTEMS

In this paper, a stable fuzzy direct control scheme is presented for a class of interconnected nonlinear systems with unknown nonlinear subsystems and unknown nonlinear interconnections. In this control algorithm, fuzzy logic systems are employed to approximate the optimal controllers, which are designed on the assumption that all dynamics for each subsystem are known; then the fuzzy controllers and adaptation mechanisms for each subsystem depend only on local measurements to provide asymptotic tracking of a reference trajectory. In addition, a fuzzy sliding mode controller is developed to compensate for the fuzzy approximating errors and attenuate the interactions between subsystems. Global asymptotic stability is established in the Lyapunov sense, with the tracking errors converging to a neighborhood of zero. A simulation example is given to illustrate the performance of the proposed method.

Properties of multivariable fuzzy controller under Gödel's implication

In this paper, we obtain the upper bounds and lower bounds for a multivariable fuzzy logic controller under Godels implication without any constraint conditions, and gave a sufficient condition in which fuzzy outputs can reach their upper and lower bounds.