Browsing by Author "Chin, Hung-I"

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Absolute Stability Analysis in Uncertain Static Fuzzy Control Systems with the Parametric Robust Popov Criterion
(2008)
Wu, Bing-Fei
;
Ma, Li-Shan
;
Perng, Jau-Woei
;
Chin, Hung-I
;
電控工程研究所
This study analyzes the absolute stability in static fuzzy logic control systems with certain and uncertain parameters. For certain static fuzzy control systems, the absolute stability can be analyzed with Popov criterion. The uncertain parameters for absolute stability analysis include the reference input, actuator gain and interval linear plant. The parametric robust Popov criterion based on Lur'e systems is applied to stability analysis respect to uncertain parameters. In our work, the parametric robust Popov criterion is applied to analyze absolute stability in static fuzzy logic control systems first time. This study can provide a valuable reference in designing fuzzy control systems. Finally, numerical simulations are provided to verify the analytical results.
Adaptive synchronization for unknown chaotic systems with fuzzy-neural network observer
(2006)
Wu, Bing-Fei
;
Ma, Li-Shan
;
Perng, Jau-Woei
;
Chin, Hung-I
;
Lee, Tsu-Tian
This investigation applies the adaptive fuzzy-neural observer (AFNO) to synchronize a class of unknown chaotic systems via scalar transmitting signal only. The proposed method can be used in synchronization if nonlinear chaotic systems can be transformed into the canonical form of Lur'e system type by the differential geometric method. In proposed approach, the receiver states can be reconstructed from one transmitted state using AFNO design. The adaptive fuzzy-niural network (INN) in AFNO is adopted to model the nonlinear term in the transmitter. Additionally, an observer is designed to estimate the other states of the master. Synchronization is achieved when all states are observed. The proposed scheme can adaptively estimated the transmitter states using AFNO, even if the transmitter changes into another chaotic system. Simulation results confirm that the proposed AFNO design is valid.
Robust control design for perturbed systems by frequency domain approach
(2007-09-01)
Wu, Bing-Fei
;
Chin, Hung-I
;
Perng, Jau-Woei
;
Lee, Tsu-Tian
;
電控工程研究所
This paper is concentrated on a perturbed vehicle control system whose gain margin (GM) and phase margin (PM) are analyzed and for which a novel controller design method satisfying the given specifications on GM, PM, and sensitivity is developed. The approach is applied to the plants with uncertain parameters that vary in intervals. Based on the parameter space method and robust stability criteria, gain and phase boundary curves are generated from the characteristic polynomial of the system with which a gain-phase tester is included in series to perform system stability analysis and controller design. The main concern in the controller design is to find a region in the controller coefficient plane so that the performance of the uncertain system satisfies given specifications. The proposed method is applied to an example of a bus system. Simulation results are given for illustration to show the system performances on GM and PM, and the desired controller meeting the specified conditions in frequency domain for the perturbed system is derived.
Robust longitudinal controller and observer design for vehicles with a riccati equation approach
(2006)
Wu, Bing-Fei
;
Ma, Li-Shan
;
Perng, Jau-Woei
;
Chin, Hung-I
;
Lee, Tsu-Tian
In this paper, the robust stabilizer with Riccati equations is applied to vehicle longitudinal system design. In our design, even if the uncertainties exist in vehicle systems, the designed observer and state feedback controller can stabilize the systems for any given initial conditions. In this method, Riccati equations are solved for finding positive-definite symmetry matrices to construct the observer and state feedback gain matrices. After the inter loop is stable, the PI controller is designed in outer loop for improving the ability of tracking performance. Finally, the simulation shows the feasibility of our design.
Stability analysis of equilibrium points in static fuzzy control systems with reference inputs and adjustable parameters
(2006)
Wu, Bing-Fei
;
Ma, Li-Shan
;
Perng, Jau-Woei
;
Chin, Hung-I
;
Lee, Tsu-Tian
In this paper, the stability in static fuzzy control systems for linear systems with different fixed reference inputs and adjustable parameters are analyzed. Under certain conditions, the unique equilibriums of error in fuzzy control systems can be solved with fixed reference. Furthermore, when the unique equilibrium is stable, the steady state error can be obtained from this stable equilibrium. Under the adjustable parameters and reference inputs, the equilibriums may have stable and unstable transformations each other respect to absolutely stability. Additionally, the insight mechanism for oscillation of equilibrium is also given with a numerical example.