Wen-Jer Chang

National Taiwan Ocean University, Keelung, Taiwan, Taiwan

Are you Wen-Jer Chang?

Claim your profile

Publications (83)40.59 Total impact

  • Wen-Jer Chang, Bo-Jyun Huang
    [Show abstract] [Hide abstract]
    ABSTRACT: The multi-constrained robust fuzzy control problem is investigated in this paper for perturbed continuous-time nonlinear stochastic systems. The nonlinear system considered in this paper is represented by a Takagi–Sugeno fuzzy model with perturbations and state multiplicative noises. The multiple performance constraints considered in this paper include stability, passivity and individual state variance constraints. The Lyapunov stability theory is employed to derive sufficient conditions to achieve the above performance constraints. By solving these sufficient conditions, the contribution of this paper is to develop a parallel distributed compensation based robust fuzzy control approach to satisfy multiple performance constraints for perturbed nonlinear systems with multiplicative noises. At last, a numerical example for the control of perturbed inverted pendulum system is provided to illustrate the applicability and effectiveness of the proposed multi-constrained robust fuzzy control method.
    ISA Transactions 09/2014; · 2.26 Impact Factor
  • Wen-Jer Chang, Fung-Lin Hsu, Bo-Jyun Huang
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper proposes a passive fuzzy controller design methodology for stabilization of nonlinear system with external disturbance based on multiplicative noised Takagi-Sugeno fuzzy model and parallel distributed compensation control design. Applying the Itô's formula and the sense of mean square, the sufficient conditions are developed to analyze the stability and to design the controller for stochastic nonlinear systems. The sufficient conditions derived in this paper belong to the linear matrix inequality forms which can be solved efficiently by convex optimal programming algorithm. Besides, the passivity theory is applied to discuss the effect of external disturbance on system. Finally, a ball and beam system is provided in the example to demonstrate the applications of the proposed fuzzy controller design technique.
    2013 International Conference on Fuzzy Theory and Its Applications (iFUZZY); 12/2013
  • Wen-Jer Chang, Bo-Jyun Huang
    [Show abstract] [Hide abstract]
    ABSTRACT: The variance and passivity constrained fuzzy control problem for the nonlinear ship steering systems with state multiplicative noises is investigated. The continuous-time Takagi-Sugeno fuzzy model is used to represent the nonlinear ship steering systems with state multiplicative noises. In order to simultaneously achieve variance, passivity, and stability performances, some sufficient conditions are derived based on the Lyapunov theory. Employing the matrix transformation technique, these sufficient conditions can be expressed in terms of linear matrix inequalities. By solving the corresponding linear matrix inequality conditions, a parallel distributed compensation based fuzzy controller can be obtained to guarantee the stability of the closed-loop nonlinear ship steering systems subject to variance and passivity performance constraints. Finally, a numerical simulation example is provided to illustrate the usefulness and applicability of the proposed multiple performance constrained fuzzy control method.
    Mathematical Problems in Engineering 03/2013; 2013. · 1.38 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This article presents an estimated state feedback fuzzy controller design method for uncertain passive discrete-time nonlinear stochastic systems with multiplicative noises. The nonlinear stochastic systems considered in this article are represented by Takagi–Sugeno (T–S) fuzzy models. For describing stochastic behaviors, stochastic differential equations are used to structure the stochastic T–S fuzzy model for representing nonlinear stochastic systems. Besides, the uncertainties of the controlled system are considered for dealing with molding errors and varying parameters. The concept of parallel distributed compensation is employed in this article to construct the estimated state feedback fuzzy controllers. Applying the Lyapunov and passivity theories, the sufficient stability conditions are derived in terms of linear matrix inequality. Finally, a numerical example is provided to show the effectiveness and applicability of the proposed fuzzy controller design approach.
    Journal- Chinese Institute of Engineers 01/2013; 36(6). · 0.24 Impact Factor
  • Wen-Jer Chang, Bo-Jyun Huang
    [Show abstract] [Hide abstract]
    ABSTRACT: A passive fuzzy controller design methodology is developed in this paper to achieve state variance constraint for continuous-time Takagi-Sugeno (T-S) fuzzy models. The proposed fuzzy controller is constructed by the concept of Parallel Distributed Compensation (PDC). Based on the Lyapunov theory, the sufficient conditions are derived to guarantee the stability of the closed-loop system. Besides, the passivity and variance constraints are also considered in the derivations of these sufficient conditions. These sufficient conditions belong to the Linear Matrix Inequality (LMI) forms, which can be solved by the convex optimal programming algorithm. Finally, the feasibility and validity of the proposed method are illustrated with a numerical simulation example.
    Power Electronics and Drive Systems (PEDS), 2013 IEEE 10th International Conference on; 01/2013
  • Wen-Jer Chang, Yao-Chung Chang
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper studies the line-integral fuzzy Lyapunov function based fuzzy controller design for continuous-time Takagi-Sugeno fuzzy systems with multiplicative noises. For stability analysis and synthesis, the sufficient conditions are derived via line-integral fuzzy Lyapunov functions. These conditions belong to the linear matrix inequality forms which can be solved by the convex optimal programming algorithm. In addition, the passivity theory is utilized to deal with the effect of external disturbance in the system. Finally, a numerical example is supplied to show the usefulness and effectiveness of the proposed design method.
    Control and Automation (ICCA), 2013 10th IEEE International Conference on; 01/2013
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a relaxed scheme of fuzzy controller design for continuous-time nonlinear stochastic systems that are constructed by the Takagi–Sugeno (T–S) fuzzy models with multiplicative noises. Through Nonquadratic Lyapunov Functions (NQLF) and Non-Parallel Distributed Compensation (Non-PDC) control law, the less conservative Linear Matrix Inequality (LMI) stabilization conditions on solving fuzzy controllers are derived. Furthermore, in order to study the effects of stochastic behaviors on dynamic systems in real environments, the multiplicative noise term is introduced in the consequent part of fuzzy systems. For decreasing the conservatism of the conventional PDC-based fuzzy control, the NQLF stability synthesis approach is developed in this paper to obtain relaxed stability conditions for T–S fuzzy models with multiplicative noises. Finally, some simulation examples are provided to demonstrate the validity and applicability of the proposed fuzzy controller design approach.
    Journal of the Franklin Institute 10/2012; 349(8):2664–2686. · 2.42 Impact Factor
  • Wen-Jer Chang, Yu-Teh Meng, Kuo-Hui Tsai
    [Show abstract] [Hide abstract]
    ABSTRACT: In this article, Takagi–Sugeno (T–S) fuzzy control theory is proposed as a key tool to design an effective active queue management (AQM) router for the transmission control protocol (TCP) networks. The probability control of packet marking in the TCP networks is characterised by an input constrained control problem in this article. By modelling the TCP network into a time-delay affine T–S fuzzy model, an input constrained fuzzy control methodology is developed in this article to serve the AQM router design. The proposed fuzzy control approach, which is developed based on the parallel distributed compensation technique, can provide smaller probability of dropping packets than previous AQM design schemes. Lastly, a numerical simulation is provided to illustrate the usefulness and effectiveness of the proposed design approach.
    International Journal of Systems Science 04/2011; 2011(pp. 1–17). · 1.31 Impact Factor
  • Wen-Jer Chang, Che-Pin Kuo, Bo-Jyun Huang
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper deals with the control problem of nonlinear stochastic ship steering system. The system exhibits nonlinear interaction on three degrees of freedom (surge, sway and yaw) by means of main propellers aft of the ship. For guaranteeing the global stability, the Takagi-Sugeno (T-S) fuzzy model is employed to represent nonlinear ship steering system. Using the technique of Imperfect Premise Matching (IPM), the fuzzy controller is designed without limitation of sharing the same membership function of the fuzzy model. In other words, the IPM technique provides a generalization in designing the fuzzy controller. Besides, the fuzzy controller design can be enhanced more flexibility and robustness than one applies Parallel Distributed Compensation (PDC) approach. Based on the Lyapunov theory, the stability conditions are derived into Linear Matrix Inequality (LMI) problems for applying the convex optimal algorithm. At last, simulation results are given to show the effectiveness of the proposed design method.
    01/2011;
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper deals with the problem of observer-based robust passive fuzzy control for uncertain Takagi-Sugeno (T-S) fuzzy model with multiplicative noises. For describing the stochastic behaviors of the system, the stochastic differential equation is used to structure the stochastic T-S fuzzy model. And, the uncertainties of the controlled system are considered in this paper for dealing with molding errors and varying parameters. Furthermore, using the Lyapunov function and passivity theory, the sufficient stability conditions can be derived in term of Linear Matrix Inequality (LMI) via two-step procedure. Finally, the numerical simulations are proposed to show the effectiveness and usefulness of this paper.
    01/2011;
  • Wei Chang, Wen-June Wang, Wen-Jer Chang
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper studies the stabilization problem of a kind of large-scale fuzzy system. The large-scale fuzzy system consists of a large number of nonlinear subsystems which are linked through time-varying interconnections. Furthermore, S-procedure is used to solve the transformation from non-LMI problem to LMI problem. Finally, a numerical simulation for a large-scale fuzzy system is given to show the applications of the present approach.
    Proceedings of the IEEE International Conference on Systems, Man and Cybernetics, Anchorage, Alaska, USA, October 9-12, 2011; 01/2011
  • Wen-Jer Chang, Che-Pin Kuo, Po-Hsun Chen
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents the stabilization conditions for designing fuzzy controller of two-link arm robot via Linear Parameter Varying (LPV) Takagi-Sugeno (T-S) fuzzy models. With the movable supportive base, the stochastic behavior of concerned system is considered in this paper for investigating the real environment. As mentioned above, combining the LPV system with T-S fuzzy model can approximate better the nonlinear two-link arm robot. Besides, the multiplicative noise term is introduced in the consequent part of fuzzy model to represent the stochastic behaviors. Based on the Lyapunov stability theory, the stability conditions are derived into Linear Matrix Inequality (LMI) problems that can be solved by using the convex optimal algorithm. Finally, simulation results are given to demonstrate the usefulness and applicability of the proposed fuzzy controller design approach.
    01/2011;
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a passive fuzzy controller design method for stabilizing the uncertain nonlinear stochastic inverted pendulum robot system. Through Takagi-Sugeno (T-S) fuzzy modeling approach, the complex nonlinear properties can be described by combining several linear sub-systems and determined membership functions. The Ito stochastic differential equation is employed to represent dynamics of systems in this paper. Applying the modeling approach, the T-S fuzzy model with multiplicative noise can be built for describing the nonlinear stochastic system. Besides, the uncertainties of the controlled system are considered in this paper for dealing with molding errors and varying parameters. Hence, the robust control problem is also discussed and investigated in this paper. Finally, the numerical simulations are proposed to show the effectiveness of the present design approach.
    FUZZ-IEEE 2011, IEEE International Conference on Fuzzy Systems, Taipei, Taiwan, 27-30 June, 2011, Proceedings; 01/2011
  • Wen-Jer Chang, Liang-Zhi Liu, Cheung-Chieh Ku
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper investigates the fuzzy control problem of a class of nonlinear continuous-time stochastic systems with achieving the passivity performance. A model-based observer feedback fuzzy control utilizing the concept of so-called parallel distributed compensation (PDC) is employed to stabilize the class of nonlinear stochastic systems that are represented by the Takagi-Sugeno (T-S) fuzzy models. Based on the Lyapunov criteria, the Linear Matrix Inequality (LMI) technique is used to synthesize the observer feedback fuzzy controller design such that the closed-loop system satisfies stability and passivity constraints, simultaneously. Finally, a numerical example is given to demonstrate the applicability and effectiveness of the proposed design method. KeywordsObserver feedback fuzzy control–parallel distributed compensation–passivity property–Takagi-Sugeno fuzzy model
    International Journal of Control Automation and Systems 01/2011; 9(3):550-557. · 0.95 Impact Factor
  • Wen-Jer Chang, Che-Pin Kuo, Cheung-Chieh Ku
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents the fuzzy controller design using Imperfect Premise Matching (IPM) for inverted pendulum robot system. With the movable supportive base, the inverted pendulum robot system can be applied to simulate human stance. Moreover, the Takagi-Sugeno (T-S) fuzzy model is employed to describe the complex nonlinearities of the system. And, the multiplicative noise term is introduced in the consequent part of fuzzy system to present the stochastic behavior of system. In order to extend the application of this paper, the IPM technique provides a generalization approach in designing proposed fuzzy controller. Based on the IPM, the fuzzy controller design can be enhanced more flexibility and robustness than one applies Parallel Distributed Compensation (PDC) approach. Finally, simulation results are given to demonstrate the usefulness and applicability of the proposed fuzzy controller design approach.
    01/2011;
  • Wen-Jer Chang, Wen-Yuan Wu, Cheung-Chieh Ku
    [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this paper is to study the H(∞) constrained fuzzy controller design problem for discrete-time Takagi-Sugeno (T-S) fuzzy systems with multiplicative noises by using the state observer feedback technique. The proposed fuzzy controller design approach is developed based on the Parallel Distributed Compensation (PDC) technique. Through the Lyapunov stability criterion, the stability analysis is completed to develop stability conditions for the closed-loop systems. Besides, the H(∞) performance constraints is also considered in the stability condition derivations for the worst case effect of disturbance on system states. Solving these stability conditions via the two-step Linear Matrix Inequality (LMI) algorithm, the observer-based fuzzy controller is obtained to achieve the stability and H(∞) performance constraints, simultaneously. Finally, a numerical example is provided to verify the applicability and effectiveness of the proposed fuzzy control approach.
    ISA Transactions 10/2010; 50(1):37-43. · 2.26 Impact Factor
  • Wen-Jer Chang, Cheung-Chieh Ku, Pei-Hwa Huang
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper focuses on the robust passive stability and stabilization problems for uncertain nonlinear stochastic time-delay systems. Via the fuzzy modeling approach, the nonlinear stochastic system is described by Takagi–Sugeno (T–S) fuzzy model in which the consequent parts are presented by linear stochastic time-delay differential equation. With Lyapunov–Krasovskii function and improved Jensen's inequality, the stability criteria are derived. In addition, the passivity theory is employed to discuss external disturbance effect on system for achieving attenuation performance. According to the proposed design method, the fuzzy controller is carried out by parallel distributed compensation (PDC) concept to guarantee the robust asymptotical stability and attenuation performance of system in the sense of mean square. Finally, a synchronous generator power system is presented to manifest the application and effectiveness of the proposed fuzzy control method.
    Fuzzy Sets and Systems 08/2010; 161:2012-2032. · 1.75 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents the relaxed nonquadratic stabilization conditions for designing fuzzy controller of inverted pendulum robot system via Takagi-Sugeno (T-S) stochastic fuzzy models. With the movable supportive base, the inverted pendulum robot system is applied to simulate human stance. Besides, the stochastic behavior of concerned system is also considered in this paper for investigating the real environment. As mentioned above, the T-S fuzzy model is used to simulate nonlinear inverted pendulum robot system. And, the multiplicative noise term is introduced in the consequent part of fuzzy system. In order to extend the application of this paper, the nonquadratic relaxed technique is employed to develop the stability conditions for finding the feasible solutions. Finally, simulation results are given to demonstrate the usefulness and applicability of the proposed fuzzy controller design approach.
    Control and Automation (ICCA), 2010 8th IEEE International Conference on; 07/2010
  • Cheung-Chieh Ku, Pei-Hwa Huang, Wen-Jer Chang
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper proposes a passive fuzzy controller design methodology for nonlinear system with multiplicative noises. Applying the Itô's formula and the sense of mean square, the sufficient conditions are developed to analyze the stability and to design the controller for stochastic nonlinear systems which are represented by the Takagi–Sugeno (T–S) fuzzy models. The sufficient conditions derived in this paper belong to the Linear Matrix Inequality (LMI) forms which can be solved by the convex optimal programming algorithm. Besides, the passivity theory is applied to discuss the effect of external disturbance on system. Finally, some numerical simulation examples are provided to demonstrate the applications of the proposed fuzzy controller design technique.
    Journal of the Franklin Institute 06/2010; 347(5):732-750. · 2.42 Impact Factor
  • Source
    Cheung-Chieh Ku, Pei-Hwa Huang, Wen-Jer Chang
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper addresses the problem of designing robust pas-sive fuzzy controller for uncertain nonlinear drum-boiler sys-tem with multiplicative noise. For this problem, the Ta-kagi-Sugeno (T-S) fuzzy model is employed to represent the nonlinearities of boiler system to be an analyzed system. Based on the T-S fuzzy model, the sufficient stability condi-tions are developed as the Linear Matrix Inequality (LMI) problem by Itô's formula and Lyapunov function. Besides, the strictly input passive theory is employed to discuss the exter-nal disturbance effect on system and investigate attenuation performance for disturbance. With applying the proposed con-troller design technique, the perturbed nonlinear boiler system with multiplicative noise can be guaranteed to be mean square stable and strict input passive.
    Journal of Marine Science and Technology. 01/2010; 18:211-220.

Publication Stats

193 Citations
40.59 Total Impact Points

Institutions

  • 1999–2012
    • National Taiwan Ocean University
      • • Department of Marine Engineering
      • • Department of Electrical Engineering
      Keelung, Taiwan, Taiwan
  • 2004
    • Air Force Institute of Technology
      Air Force Academy, Colorado, United States
  • 2002–2004
    • National Central University
      • Department of Electrical Engineering
      Taoyuan City, Taiwan, Taiwan