Ti-Hung Chen

Adaptive fuzzy sliding mode control for a class of underactuated systems

This paper proposes an adaptive fuzzy sliding-mode controller for a class of underactuated systems. Here, the underactuated system is decoupled into two subsystems, and respectively define a sliding surface for each subsystem. The fuzzy models are applied to estimate the unknown functions of the controlled underactuated system. Then, we will propose the adaptive fuzzy sliding model controller to guarantee the tracking performance. Finally, computer simulations are given to demonstrate the tracking performance of the proposed control strategy.

Quasi-sliding mode control for a class of multivariable discrete time bilinear systems

In this paper, we adopt the two quasi-sliding mode control for a class of multivariable discrete time bilinear systems. By applying the proposed control strategies, the system states would move into a boundary layer of the sliding surface and remain in the boundary layer in finite time. Thus, the stability of the overall system could be guaranteed. Finally, the computer simulation is applied to illustrate the control performance of the proposed control strategies.

The fuzzy c-regression model for lithium battery

In this paper, the fuzzy c-regression model of the lithium battery and its application to the estimation of the state of charge (SOC) is proposed. We apply the fuzzy c-regression models (FCRM) to formulate the parameters in the equivalent circuit model (ECM) of the lithium battery. Based on these fuzzy c-regression models, we can estimate the SOC of the given lithium battery. The direct current internal resistance (DCIR) test method under the room temperature is applied to determine the parameters of the ECM. Simulation results demonstrate the effectiveness of the proposed approach.

Discrete sliding mode controller design with fast output sampling technique for discrete-time T-S fuzzy system

In this paper, the discrete sliding mode control (DSMC) design with fast output sampling (FOS) technique for discrete-time T-S fuzzy system is presented. To guarantee the stability of the overall system, the control law of DSMC with the system state is adopted. Instead of applying the state observer to estimate the system state, we apply the FOS technique and identify the relation between the system state and the system output for the multi-rate system. Thus, the control law of DSMC would be redesigned as the function of the system output. This method is more practical and simple to implement the applying the state observer. Simulation results would demonstrate the effectiveness of the proposed control strategy.

Decentralized adaptive fuzzy integral sliding mode control for a class of large-scale system

This paper presents a decentralized adaptive fuzzy integral sliding mode controller (DAFISMC) for a class of large-scale systems in which not all the system states are available for measurement, but the system outputs are measurable. First, we adopt a fuzzy model to approximate the large scale system, and then design an observer to estimate the system states. Next, we propose a DAFISMC to control the large-scale system such that the tracking performance of the overall control system can be achieved. By the strictly-positive-real Lyapunov stability theorem, the stability of the overall system is analyzed. Computer simulations are given to demonstrate the effectiveness of the proposed control strategy.

Piecewise H-infinity Controller Design for a Class of T-S Fuzzy Systems with Time Delay

In this paper, a piecewise Hinfin controller design is proposed for a class of T-S fuzzy systems with time-delay. For a given T-S fuzzy system, we design the observer to estimate the states and the controller to guarantee the global stability with Hinfin performance of the resulting closed loop fuzzy control system. Subsequently, the controller design problem is characterized in terms of three LMIs, the first one is for the control gain with the current states, the second one is for the control gain with the time-delay states, and the third one is for observer gain. Finally, a simulation example illustrates the design procedure and demonstrates the performance of the proposed control strategy.

Vibration and Stability of Initially Stressed Hybrid Composite Plates in Hygrothermal Environments

Vibration and stability of hybrid composite plates with arbitrary initial stresses in hygrothermal environments are investigated. The governing equations, including the effects of moisture-caused, thermal, and initial stresses, are established based on the variational energy method. The influence of temperature and moisture on material properties of the hybrid composite plates is considered. The initial stress is taken to be a combination of a uniaxial load and pure bending. Example of an initially and hygrothermally stressed hybrid laminated plate with simply supported edges is solved. Effects of the layer thickness ratio, fiber volume fraction, initial stresses, temperature, and moisture concentration on the natural frequency and buckling load of hybrid composite plates are studied.

Estimation of the asympototic stability region of uncertain fuzzy systems with bounded controllers using variable structure system design approach

In this paper, the problem of estimating the asymptotic stability region (ASR) of uncertain nonlinear systems is considered. Our approach is based on Takagi-Sugeno (T-S) fuzzy model and variable structure control (VSC) technique. To simplify the problem, we use a state transformation to reduce the system order of the T-S fuzzy systems. Then we design the sliding surface for the transformed system. By the Lyaponov stability theorem, the ASR can be estimated. A simulation example is presented to verify the effectiveness of the proposed scheme.

The quasi-sliding mode control for a class of discrete-time bilinear systems

In this paper, we propose the two quasi-sliding mode control for bilinear systems. By proper choice of the parameters in the control law, the system states will move within the quasi-sliding mode control band. Finally, the simulations are given to illustrate the effectiveness of the proposed controller.

The piecewise Lyapunov functions based the delay-independent H ∞ controller design for a class of time-delay T-S fuzzy system

This paper presents the piecewise Lyapunov functions based the delay- independent Hinfin controller design for a class of time-delay T-S fuzzy system. First, we apply a piecewise observer to estimate the states. Then, a piecewise delay-independent Hinfin controller is designed to guarantee the Hinfin performance. Subsequently, the problem of control design is characterized in terms of two LMIs, one for the control gain and the other for observer gain, and the LMIs can be effectively solved by convex optimization technique. Simulation results demonstrate the applicability and the effectiveness of the proposed controller.