H. Ohtake

Kyushu Institute of Technology, Kitakyūshū, Fukuoka, Japan

Are you H. Ohtake?

Claim your profile

Publications (186)195.1 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: This study presents a nonmonotonically decreasing relaxation approach of Lyapunov functions to guaranteed cost control for discrete Takagi-Sugeno (T-S) fuzzy systems. First, the authors summarise the previous results on a relaxation of nonmonotonically decreasing of Lyapunov functions, and newly derive one lemma based on the previous results. Based on the newly derived lemma, they propose guaranteed cost control design for discrete T-S fuzzy systems. The design conditions can be represented in terms of linear matrix inequalities and provide more relaxed results than the existing approach. A design example is included to demonstrate the relaxation effectiveness of the proposed approach in guaranteed cost control.
    IET Control Theory and Applications 11/2014; 8(16):1716-1722. DOI:10.1049/iet-cta.2013.1132 · 1.84 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study presents a sum-of-squares (SOS) approach to stable control and guaranteed cost control of discrete polynomial fuzzy systems. The SOS framework presented in this paper offers a new paradigm over the existing linear matrix inequality (LMI) approaches to discrete Takagi-Sugeno (T??S) fuzzy models. At first, this study, newly introduces a discrete polynomial fuzzy model that is more general and effective than the well-known discrete T-S fuzzy model. With considering the operating domain, stable control design conditions are then derived based on state-dependent Lyapunov functions that contain quadratic Lyapunov functions as a special case. Hence, the design approach discussed in this study could be more general than the LMI design approaches based on quadratic Lyapunov functions. Moreover, this study also discusses a guaranteed cost control design which is carried out by minimising the upper bound of a given performance function. All the design conditions derived in this study can be represented in terms of SOS and are symbolically and numerically solved via the SOSOPT and the SeDuMi, respectively. Finally, the ball-and-beam system is provided as an example to illustrate the utility of the proposed SOS-based design approach.
    IET Control Theory and Applications 03/2014; 8(4):288-296. DOI:10.1049/iet-cta.2013.0645 · 1.84 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The dependence of a carbon black (CB) dispersion in a tensile-tested specimen of a vulcanized rubber on the compounding ratio of CB was evaluated by terahertz time-domain spectroscopy (THz-TDS). The near broken-out section of the specimens were investigated by THz-TDS, and the distribution of the absorbance in the THz regime, which directly affected by the CB dispersion, was investigated. It was found that the THz image of the CB dispersion in the samples showed a biased distribution between the fixed side and the pulled side of the tensile-tested specimens. It was also found that the difference of the CB dispersion of the both sides was decreased with the CB ratio.
    Lasers and Electro-Optics Pacific Rim (CLEO-PR), 2013 Conference on; 01/2013
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper proposes the minimum-type piecewise-Lyapunov-function-based switching fuzzy controller that switches accompanying the piecewise Lyapunov function. By applying this switching fuzzy controller with the minimum-type piecewise Lyapunov function, the relaxed stabilization criterion is obtained for continuous Takagi-Sugeno (T-S) fuzzy systems. Some conditions of the relaxed stabilization criterion are represented by bilinear matrix inequalities (BMIs), which contain some bilinear terms as the product of a full matrix and a scalar. According to the literature, the path-following method is very effective for this kind of BMI problem; hence, it is utilized to obtain solutions of the criterion. Xie et al. in 1997 chose two types (i.e., minimum type and maximum type) of piecewise Lyapunov functions as the Lyapunov function candidates. The reasons for why this study only chooses the minimum-type piecewise Lyapunov function as the Lyapunov function candidate are illustrated. Moreover, the numerical example shows the relaxation of the proposed criterion.
    IEEE Transactions on Fuzzy Systems 12/2012; 20(6):1166-1173. DOI:10.1109/TFUZZ.2012.2196049 · 6.31 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Piecewise Lyapunov functions and non-quadratic Lyapunov functions have been employed to analyse Takagi-Sugeno (T-S) fuzzy systems for getting relaxed results in the literature. Nevertheless, until now piecewise non-quadratic Lyapunov functions have not been used to design T-S fuzzy control systems. Motivated by the aforementioned concerns, this study utilises the minimum-type piecewise non-quadratic Lyapunov function to design the discrete T-S fuzzy control system. Based on the piecewise non-quadratic Lyapunov function, the switching non-parallel distributed compensation control law is proposed to obtain the relaxed stabilisation criterion. Owing to that some conditions of the proposed criterion are bilinear matrix inequalitiy conditions, the particle swarm optimisation algorithm is applied for finding out the solution of the criterion. An example is provided to illustrate the effectiveness of the proposed criterion.
    IET Control Theory and Applications 08/2012; 6(12):1918-1925. DOI:10.1049/iet-cta.2010.0697 · 1.84 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper proposes shared control in wireless-based remote stabilization for nonlinear systems. Shared control that is newly named in this paper can be regarded as simultaneous stabilization of plural nonlinear systems (in different places) by a single (common) controller. This paper consists of two parts. The first part addresses the basis of wireless-based remote stabilization for a single nonlinear system with time-varying delay. We derive a delay-dependent sufficient condition for ensuring the stability of Takagi–Sugeno (T-S) fuzzy models with time-varying delays that are globally (or semiglobally at least) equivalent to nonlinear systems with wireless communication time delays. A feature of the derived condition is to be able to obtain the maximum time delay for ensuring the stability of wireless-based remote control system for given feedback gains. The second part presents shared control of plural nonlinear systems via a single controller. To design a (common) shared controller to stabilize plural nonlinear systems, we derive also a shared control version of the stability condition for T-S fuzzy models with time-varying delays. Design examples demonstrate the utility of this proposed design approach.
    IEEE/ASME Transactions on Mechatronics 06/2012; 17(3):443-453. DOI:10.1109/TMECH.2012.2187303 · 3.65 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents wireless vision-based stabilization of an indoor microhelicopter via visual simultaneous localization and mapping. The so-called parallel tracking and mapping (PTAM) technique using a small single wireless camera on the helicopter is utilized to detect the position and attitude of the helicopter. We construct the measurement system that is able to calibrate the mapping between local coordinate system in the PTAM and world coordinate system and is able to realize noise detection and elimination. In addition, we design the guaranteed cost (stable) controller for the dynamics of the helicopter via a linear matrix inequality approach. Although path tracking control only via the small single wireless vision sensor is a quite difficult task, the control results demonstrate the utility of our approach.
    IEEE/ASME Transactions on Mechatronics 06/2012; 17(3):519-524. DOI:10.1109/TMECH.2011.2181532 · 3.65 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a sum-of-squares (SOS) approach to polynomial fuzzy observer designs for three classes of polynomial fuzzy systems. The proposed SOS-based framework provides a number of innovations and improvements over the existing linear matrix inequality (LMI)-based approaches to Takagi-Sugeno (T-S) fuzzy controller and observer designs. First, we briefly summarize previous results with respect to a polynomial fuzzy system that is a more general representation of the well-known T-S fuzzy system. Next, we propose polynomial fuzzy observers to estimate states in three classes of polynomial fuzzy systems and derive SOS conditions to design polynomial fuzzy controllers and observers. A remarkable feature of the SOS design conditions for the first two classes (Classes I and II) is that they realize the so-called separation principle, i.e., the polynomial fuzzy controller and observer for each class can be separately designed without lack of guaranteeing the stability of the overall control system in addition to converging state-estimation error (via the observer) to zero. Although, for the last class (Class III), the separation principle does not hold, we propose an algorithm to design polynomial fuzzy controller and observer satisfying the stability of the overall control system in addition to converging state-estimation error (via the observer) to zero. All the design conditions in the proposed approach can be represented in terms of SOS and are symbolically and numerically solved via the recently developed SOSTOOLS and a semidefinite-program solver, respectively. To illustrate the validity and applicability of the proposed approach, three design examples are provided. The examples demonstrate the advantages of the SOS-based approaches for the existing LMI approaches to T-S fuzzy observer designs.
    IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics: a publication of the IEEE Systems, Man, and Cybernetics Society 04/2012; 42(5):1330-42. DOI:10.1109/TSMCB.2012.2190277 · 3.78 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents hovering control of an indoor micro helicopter only using single visual sensor feedback. The control technique is based on the parallel tracking and mapping (PTAM), a kind of visual simultaneous localization and mapping, using a small single wireless camera on the helicopter. The six degree of freedom of the helicopter is detected via the PTAM. The nonlinear dynamics of the helicopter is converted to a Takagi-Sugeno fuzzy model. To design the guaranteed cost (stable) controller, a Takagi-Sugeno fuzzy model-based design is carried out via a linear matrix inequality approach. The hovering control results demonstrate the utility of our approach even though single wireless vision sensor based stabilization is extremely a difficult task in practice.
    Decision and Control (CDC), 2012 IEEE 51st Annual Conference on; 01/2012
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents fuzzy model-based servo control for a class of nonlinear descriptor systems. In our previous paper, servo control based on error dynamics using error vector and input difference was proposed. In this paper, we extend the servo control technique to nonlinear descriptor systems. The descriptor system can represent larger class of nonlinear systems than the typical state-space models. We show the construction method of fuzzy descriptor system for servo control and derive servo controller design conditions for fuzzy descriptor systems in the form of LMI. Moreover, the servo control which is applicable to switching of target point is also discussed. Design examples illustrate the utility of this approach.
    Fuzzy Systems (FUZZ-IEEE), 2012 IEEE International Conference on; 01/2012
  • Source
    Kazuo Tanaka, Hiroshi Ohtake, Toshiaki Seo, H.O. Wang
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a sum of squares (SOS, for brevity) based observer design for a more general class of polynomial fuzzy systems with the polynomial matrices A<sub>i</sub>(x(t)) and B<sub>i</sub>(x(t)) that are permitted to be dependent of the states x(t). First, we briefly summarize previous works on SOS-based observer designs for two limited classes of polynomial fuzzy systems. To overcome the difficulty of the fact that does not realize the so-called separation principle design for the more general class, this paper provides a practical design procedure of a polynomial fuzzy controller and a polynomial fuzzy observer without lack of guaranteeing the stability of the overall control system in addition to converging state estimation error (via the observer) to zero. The design approach discussed in this paper is more general than the existing LMI approaches (to T-S fuzzy controller and observer designs) and also than the previous SOS-based observer designs. To illustrate the validity of the design approach, a design example is provided. The example shows the utility of our SOS approach to the polynomial fuzzy observer-based control for the more general class of polynomial fuzzy systems.
    American Control Conference (ACC), 2011; 08/2011
  • Hiroshi Ohtake, Kazuo Tanaka, Hua O. Wang
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents an improved approach to servo control for nonlinear systems with constraints on inputs and states using the fuzzy model-based control approach. In our previous paper, servo control based on error dynamics using error vector and input difference was proposed. Although the approach can achieve servo control with constraints on both of inputs and states, error dynamics with time-varying extra terms cannot be applied. In this paper, time-varying cancellation input is newly introduced. By using the cancellation input, servo control for error dynamics with time varying extra terms is achieved. We derive servo controller design conditions and constraint conditions on inputs and states in the form of LMI. Design examples illustrate the utility of this approach.
    Proceedings of the American Control Conference 06/2011; DOI:10.1109/ACC.2011.5991129
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a polynomial fuzzy observer design for a wider class of polynomial fuzzy systems via a sum of squares (SOS, for brevity) approach. The proposed SOS-based framework provides a number of innovations and improvements over the existing LMI-based approaches to Takagi-Sugeno (T-S) fuzzy controller and observer designs. First, we briefly summarize previous results for a class of polynomial fuzzy systems that is more general representation of the well-known T-S fuzzy system. Next, we propose a polynomial fuzzy observer to estimate states in a wider class of polynomial fuzzy systems and derive SOS conditions to design polynomial fuzzy controllers and observers. A remarkable feature of the SOS design conditions is that they realize the so-called separation principle, that is, that a polynomial fuzzy controller and observer for this class can be separately designed without lack of guaranteeing the stability of the overall control system in addition to converging state estimation error (via the observer) to zero. The design conditions in the proposed approach can be represented in terms of SOS and are symbolically and numerically solved via the recent developed SOSTOOLS and a semidefinite program (SDP) solver, respectively. To illustrate the validity and applicability of the proposed approach, a design example is provided. The example demonstrates advantages of the SOS-based approach for the existing LMI approaches to T-S fuzzy observer designs.
    FUZZ-IEEE 2011, IEEE International Conference on Fuzzy Systems, Taipei, Taiwan, 27-30 June, 2011, Proceedings; 01/2011
  • [Show abstract] [Hide abstract]
    ABSTRACT: We have estimated the intensity change in THz pulses emitted from a dipole-type photoconductive antenna as a function of the beam deflection of a pumping laser. The result shows the beam deflection affects the intensity variation of THz pulses comparable to the random errors in the THz-TDS measurements.
    01/2011; DOI:10.1109/irmmw-THz.2011.6104879
  • Hiroshi Ohtake, Kazuo Tanaka, H.O. Wang
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents servo control for nonlinear systems with constraints on both of inputs and states using the fuzzy model-based control approach. In our previous paper, we proposed servo control with input constraint by introducing input difference between present input and final input. However, it is difficult to constrain both of state of the nonlinear systems and the control input at the same time since time-derivatives of state are used. In this paper, we construct the nonlinear error system based on error vector between state and the target point for servo control. By employing the error system representation and the input difference, servo control with constraints on both of inputs and states can be achieved. We derive LMI conditions for designing servo controller and for constraining control inputs and states. Servo controller with constraints is designed by simultaneously solving servo controller design condition and the constraint conditions. A design example illustrates the utility of this approach.
    Intelligent Control (ISIC), 2010 IEEE International Symposium on; 10/2010
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents a sum of squares (SOS, for brevity) approach to polynomial fuzzy observer design for polynomial fuzzy systems. First, we briefly summarize previous results with respect to a polynomial fuzzy system and controller that are more general representation of the well-known Takagi-Sugeno (T-S) fuzzy system and controller, respectively. Secondly, we propose a polynomial fuzzy observer to estimate states of the polynomial fuzzy system and derive an SOS condition to design a polynomial fuzzy controller and observer. A key feature of the SOS design condition is that it realizes the so-called separation principle, that is, that a polynomial fuzzy controller and a polynomial fuzzy observer can be separately designed without lack of guaranteeing the stability of the overall control system. The design approach discussed in this paper is more general than the existing LMI approaches (to T-S fuzzy controller and observer designs). In addition, the design condition in the proposed approach can be represented in terms of SOS and is symbolically and numerically solved via the recent developed SOSTOOLS and a semidefinite program (SDP) solver, respectively. To illustrate the validity of the design approach, a design example is provided. The example shows the utility of our SOS approach to the polynomial fuzzy observer-based control.
    Decision and Control, 2009 held jointly with the 2009 28th Chinese Control Conference. CDC/CCC 2009. Proceedings of the 48th IEEE Conference on; 01/2010
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In this study, the piecewise Lyapunov function based switching fuzzy controller is proposed to get a relaxed criterion for the H<sub>∞</sub> control of continuous T-S fuzzy systems. The particle swarm optimization (PSO) algorithm, which is useful for nonlinear optimization problem, is utilized with the LMI tool to get the optimal H<sub>∞</sub> performance due to that some conditions of the criterion are bilinear with the s-procedure parameters. The simulation results have shown the validity of the proposed H<sub>∞</sub> control method.
    Decision and Control, 2009 held jointly with the 2009 28th Chinese Control Conference. CDC/CCC 2009. Proceedings of the 48th IEEE Conference on; 01/2010
  • H. Ohtake, K. Tanaka, H.O. Wang
    [Show abstract] [Hide abstract]
    ABSTRACT: This correspondence presents servo and nonlinear model following controls for a class of nonlinear systems using the Takagi-Sugeno fuzzy model-based control approach. First, the construction method of the augmented fuzzy system for continuous-time nonlinear systems is proposed by differentiating the original nonlinear system. Second, the dynamic fuzzy servo controller and the dynamic fuzzy model following controller, which can make outputs of the nonlinear system converge to target points and to outputs of the reference system, respectively, are introduced. Finally, the servo and model following controller design conditions are given in terms of linear matrix inequalities. Design examples illustrate the utility of this approach.
    IEEE TRANSACTIONS ON CYBERNETICS 01/2010; · 3.47 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents the stability analysis for polynomial fuzzy systems by utilizing the equality constraints of sum-of-squares (SOS) Program. Recently, T-S fuzzy systems have been extended to polynomial fuzzy systems, in which the consequent parts could be polynomial sub-systems. Moreover, stability and stabilization analyses for polynomial fuzzy systems have been done based on polynomial Lyapunov functions that contain quadratic Lyapunov functions as a special case. Since polynomials exist in the sub-systems and the positive definite matrices of the Lyapunov functions, the linear matrix inequality (LMI) tools are not valid for the polynomial analyses. Instead of LMI tools, SOSTOOLS of Matlab toolbox is applied to solve solutions for the polynomial analyses. The SOS program of SOSTOOLS can solve two kinds of constraints that are equality constraints and inequality constraints. The existing stability and stabilization analyses for polynomial fuzzy systems represent their conditions only in the inequality constraints. This paper analyzes the stability of the polynomial fuzzy systems by polynomial Lyapunov functions, and represents the new stability conditions not only in terms of the inequality constraints but also in terms of the equality constraints.
  • [Show abstract] [Hide abstract]
    ABSTRACT: This paper presents stability analysis of nonlinear systems using a new type of Lyapunov functions. We define so-called multiple mixed max-min based Lyapunov functions that contain existing piecewise Lyapunov functions as a special case. The extension is realized by multiple mixed connection of max and min operations for plural local quadratic functions. Hence, stability analysis discussed in this paper is more relaxed than those based on existing piecewise Lyapunov functions in addition to quadratic Lyapunov functions. Relaxed stability conditions based on multiple mixed max-min based Lyapunov functions are derived by considering switching conditions among the plural local quadratic functions. The derived stability conditions are represented in terms of bilinear matrix inequalities (BMIs). Unfortunately, BMIs cannot be generally solved via LMI solvers. Therefore, to simply solve BMIs, we propose a practical way that combines an LMI solver and particle swarm optimization. In this paper, two analytical examples are provided. The examples illustrate that our approach provides more relaxed stability results than existing piecewise Lyapunov functions approaches.
    FUZZ-IEEE 2010, IEEE International Conference on Fuzzy Systems, Barcelona, Spain, 18-23 July, 2010, Proceedings; 01/2010

Publication Stats

2k Citations
195.10 Total Impact Points

Institutions

  • 2012–2014
    • Kyushu Institute of Technology
      Kitakyūshū, Fukuoka, Japan
  • 2001–2012
    • The University of Electro-Communications
      • Department of Mechanical Engineering and Intelligent Systems
      Edo, Tōkyō, Japan
    • Chiba University
      • Graduate School of Science and Technology
      Tiba, Chiba, Japan
    • Kobe University
      • Department of Chemistry
      Kōbe, Hyōgo, Japan
  • 2007
    • Boston University
      • Department of Mechanical Engineering
      Boston, Massachusetts, United States
  • 2005–2006
    • Osaka University
      • Department of Biotechnology
      Suita, Osaka-fu, Japan
  • 2001–2006
    • NEC Corporation
      Edo, Tōkyō, Japan
  • 1999–2006
    • Tohoku University
      • • Institute of Fluid Science
      • • Institute for Materials Research
      Japan
  • 1993–2006
    • Hiroshima University
      • • Department of Molecular Biotechnology
      • • Graduate School of Engineering
      Hiroshima-shi, Hiroshima-ken, Japan
  • 1999–2001
    • Institute for Molecular Science
      Okazaki, Aichi, Japan
  • 2000
    • Fukuyama University
      Hukuyama, Hiroshima, Japan
  • 1998
    • National Fisheries University
      Simonoseki, Yamaguchi, Japan