SANO Hideki | ![]() |
Graduate School of System Informatics / Department of System Science | |
Professor | |
Mathematics |
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In this paper, we study the problem of stabilizing one-dimensional parabolic systems with input delay. Especially, we consider the case of “distributed control”. The purpose is to derive the stabilizing controller of predictor type in an abstract space, by using a backstepping method combined with the semigroup theory. The use of the semigroup theory makes the proof of continuity of the inverse transformation easy. Also, it is shown that the abstract controller can be actually implemented by using a finite number of eigenvalues and eigenfunctions of the system operator. Finally, a numerical simulation result is presented to demonstrate our design method.
Springer Tokyo, 01 Jul. 2018, Japan Journal of Industrial and Applied Mathematics, 35 (2), 477 - 496, English[Refereed]
Scientific journal
This paper is concerned with reduction of the order of finite-dimensional stabilizing controllers for a class of distributed parameter systems. Since the middle of the 1980s, the design method of finite-dimensional stabilizing controllers of Sakawa type has been generalized for a wider class of parabolic distributed parameter systems with boundary control and/or boundary observation. The controller of Sakawa type consists of two kinds of observers: one is an observer of Luenberger type and the other is an estimator for residual modes. Especially, the latter is called residual mode filter (RMF), and it plays an essential role in the design of finite-dimensional stabilizing controllers when the order of RMF is “sufficiently large”. The purpose of this paper is to propose the design method containing low order RMF. An approach based on stability radius is employed.
Elsevier Ltd, 01 Jun. 2018, Automatica, 92, 49 - 55, English[Refereed]
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This paper is concerned with the stability analysis of a distributed parameter circuit with dynamic boundary condition. The distributed parameter circuit is written by the telegrapher's equations whose boundary condition is described by an ordinary differential equation. First of all, it is shown that, for any physical parameters of the circuit, the system operator generates an exponentially stableC0-semigroup on a Hilbert space. However, it is not clear whether the decay rate of the semigroup is the most precise one. In this paper, the spectral analysis is conducted for the system satisfying the distortionless condition, and it is shown that the semigroup satisfies the spectrum determined growthcondition.
Elsevier B.V., 01 Jan. 2018, Systems and Control Letters, 111, 34 - 39, English[Refereed]
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This paper concerns the H-infinity control problem of a coupled transport-diffusion system with Neumann boundary condition, related to parallel-flow heat exchange process. It is shown that, by using the previous approach for a single diffusion system, the H-infinity control problem can be solved by constructing a residual mode filter (RMF)-based controller which is of finite-dimension. A numerical simulation result is given to demonstrate the validity of the proposed method.
POLSKA AKAD NAUK, POLISH ACAD SCI, DIV IV TECHNICAL SCIENCES PAS, Feb. 2017, BULLETIN OF THE POLISH ACADEMY OF SCIENCES-TECHNICAL SCIENCES, 65 (1), 11 - 19, English[Refereed]
Scientific journal
Background: In mathematical epidemiology, age-structured epidemic models have usually been formulated as the boundary-value problems of the partial differential equations. On the other hand, in engineering, the backstepping method has recently been developed and widely studied by many authors. Methods: Using the backstepping method, we obtained a boundary feedback control which plays the role of the threshold criteria for the prediction of increase or decrease of newly infected population. Under an assumption that the period of infectiousness is same for all infected individuals (that is, the recovery rate is given by the Dirac delta function multiplied by a sufficiently large positive constant), the prediction method is simplified to the comparison of the numbers of reported cases at the current and previous time steps. Results: Our prediction method was applied to the reported cases per sentinel of influenza in Japan from 2006 to 2015 and its accuracy was 0.81 (404 correct predictions to the total 500 predictions). It was higher than that of the ARIMA models with different orders of the autoregressive part, differencing and moving-average process. In addition, a proposed method for the estimation of the number of reported cases, which is consistent with our prediction method, was better than that of the best-fitted ARIMA model ARIMA(1, 1, 0) in the sense of mean square error. Conclusions: Our prediction method based on the backstepping method can be simplified to the comparison of the numbers of reported cases of the current and previous time steps. In spite of its simplicity, it can provide a good prediction for the spread of influenza in Japan.
BIOMED CENTRAL LTD, May 2016, THEORETICAL BIOLOGY AND MEDICAL MODELLING, 13 (1), English[Refereed]
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This paper is concerned with the exponential stability of heat exchangers with delayed boundary feedback. Especially, heat exchangers of counter-flow type/parallel-flow type are treated, where they are respectively described by a coupled hyperbolic equations with time lag in the boundary feedback loop. When time lag does not exist, the exponential stability has been shown for counter-flow type by using the port Hamiltonian approach as well as the spectral analysis, and the conditions for the exponential stability to be assured are given. In this paper, time lag is expressed by using a transport equation, and the port Hamiltonian approach is applied to the whole system. A condition for the system with time lag to be exponentially stable is derived for counter-flow type and parallel-flow type. (C) 2016, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.
ELSEVIER SCIENCE BV, 2016, IFAC PAPERSONLINE, 49 (8), 43 - 47, English[Refereed]
International conference proceedings
In this paper, we discuss the problem of approximating stability radius appearing in the design procedure of finite-dimensional stabilizing controllers for an infinite-dimensional dynamical system. The calculation of stability radius needs the value of H-infinity-norm of a transfer function whose realization is described by infinite-dimensional operators in a Hilbert space. From the computational point of view, we need to prepare a family of approximate finite-dimensional operators and then to calculate the H-infinity-norm of their transfer functions. However, it is not assured that they converge to the value of H-infinity-norm of the original transfer function. The purpose of this study is to justify the convergence. In a numerical example, we treat parabolic distributed parameter systems with distributed control and distributed/boundary observation.
KYBERNETIKA, 2016, KYBERNETIKA, 52 (5), 824 - 835, English[Refereed]
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In this paper, we consider the H∞ control problem of a coupled transport-diffusion system related to parallel-flow heat exchange process. It is shown that, by using our previous result for a single diffusion system, the H∞ control problem can be solved by constructing a residual mode filter (RMF)-based controller which is of finite-dimension.
01 Oct. 2015, IFAC-PapersOnLine, 28 (25), 50 - 55, English[Refereed]
International conference proceedings
This paper is concerned with the problem of stabilizing one-dimensional parabolic systems related to formations by using finite-dimensional controllers of a modal type. The parabolic system is described by a Sturm-Liouville operator, and the boundary condition is different from any of Dirichlet type, Neumann type, and Robin type, since it contains the time derivative of boundary values. In this paper, it is shown that the system is formulated as an evolution equation with unbounded output operator in a Hilbert space, and further that it is stabilized by using an RMF (residual mode filter)-based controller which is of finite-dimension. A numerical simulation result is also given to demonstrate the validity of the finite-dimensional controller.
POLSKA AKAD NAUK, POLISH ACAD SCI, DIV IV TECHNICAL SCIENCES PAS, Mar. 2015, BULLETIN OF THE POLISH ACADEMY OF SCIENCES-TECHNICAL SCIENCES, 63 (1), 295 - 303, English[Refereed]
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In this paper, we consider the problem of enhancing the stability of a coupled transport-diffusion system related Ito parallel-flow heat exchange process. It is shown that the degree of stability can be enhanced by using a residual mode filter (RMF)-based controller which is of finite-dimension.
01 Feb. 2015, IFAC-PapersOnLine, 28 (1), 755 - 760, English[Refereed]
International conference proceedings
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In this paper, we study the finite-dimensional stabilization problem of the cascade consisting of the one-dimensional transport-diffusion process and an unstable Ordinary Differential Equation ( ODE) plant, where the ODE plant is connected with the transport-diffusion process through a filter. The input to the whole system is only Dirichlet boundary input to the transportdiffusion process, and the outputs are the Dirichlet data at the boundary of process domain and the output from the ODE plant. In this paper, we use the latest method and show that the one-dimensional transport-diffusion process with such input and output can be formulated as a system with A.-bounded output operator and direct feedthrough term. It is shown that, under the assumption that the ODE plant is controllable and observable, the finite-dimensional model of the whole system becomes controllable and observable, when the filter mentioned above is a Residual Mode Filter ( RMF). This fact enables us to construct a finite-dimensional stabilizing controller by using an RMF approach.
IEEE, 2014, 2014 INTERNATIONAL CONFERENCE ON MATHEMATICS AND COMPUTERS IN SCIENCES AND IN INDUSTRY (MCSI 2014), 261 - 266, English[Refereed]
International conference proceedings
This paper is concerned with observability and the related problem for a parallel flow two-fluid heat exchanger equation with diffusive terms. The observability results are stated under two kinds of boundary observations and the eigenvalues of the observability gramians are discussed. When one considers the inverse problem of estimating the initial states under the observations, it is expected that the reconstruction of the initial states under the observation at one outlet becomes more difficult than that under the observation at two outlets, from the physical point of view. The purpose of this paper is to explain the intuitive fact by using the eigenvalues of the observability gramians. © 2012 The authors 2012. Published by Oxford University Press on behalf of the Institute of Mathematics and its Applications. All rights reserved.
Dec. 2013, IMA Journal of Mathematical Control and Information, 30 (4), 463 - 472, English[Refereed]
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This paper is concerned with observability and the related problem for a parallel flow two-fluid heat exchanger equation with diffusive terms. The observability results are stated under two kinds of boundary observations and the eigenvalues of the observability gramians are discussed. When one considers the inverse problem of estimating the initial states under the observations, it is expected that the reconstruction of the initial states under the observation at one outlet becomes more difficult than that under the observation at two outlets, from the physical point of view. The purpose of this paper is to explain the intuitive fact by using the eigenvalues of the observability gramians.
OXFORD UNIV PRESS, Dec. 2013, IMA JOURNAL OF MATHEMATICAL CONTROL AND INFORMATION, 30 (4), 463 - 472, English[Refereed]
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We investigate the problem of enhancing the stability of a coupled transport-diffusion system with Dirichlet actuation and Dirichlet measurement. In the recent paper [H. Sano, Neumann boundary control of a coupled transport-diffusion system with boundary observation, J. Math. Anal. Appl. 377 (2011) 807-816], we treated the stabilization problem for the case with Neumann actuation and Dirichlet measurement, where the variable transformation of the state is performed by using the fractional power of an unbounded operator. However, we cannot use the similar transformation for the case with Dirichlet actuation and Dirichlet measurement, since it brings an ill-posed expression of the system. So, we use an algebraic approach for the formulation of the system. In this paper, it is shown that a reduced-order model with a finite-dimensional state variable is controllable and observable. The fact enables us to construct a finite-dimensional stability-enhancing controller for the original infinite-dimensional system by using a residual mode filter (RMF) approach. The novelty of this paper is the structure that the controller contains the dynamics with respect to the control variable. As a result, the state vector of the resulting closed-loop system includes the control variable as its entry. (C) 2011 Elsevier Inc. All rights reserved.
ACADEMIC PRESS INC ELSEVIER SCIENCE, Apr. 2012, JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS, 388 (2), 1194 - 1204, English[Refereed]
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In this paper, we consider an output tracking problem of a parallel-flow heat exchange process with distributed and boundary inputs. As the distributed inputs to the system, the output feedback control is first applied. Under zero boundary inputs, it is shown that the C(0) -semigroup describing the closed-loop system satisfies the spectrum determined growth condition. Next, we apply a backstepping method to the design of the boundary inputs for output tracking. Our main result shows that the output of the system reaches a reference signal in finite time under both the output feedback control and the boundary control law derived by the backstepping method. (C) 2011 Elsevier B.V. All rights reserved.
ELSEVIER SCIENCE BV, Nov. 2011, SYSTEMS & CONTROL LETTERS, 60 (11), 917 - 921, English[Refereed]
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We study the Neumann boundary stabilization problem of a coupled transport-diffusion system in the case where the observation is done at the boundary. In the recent paper of Sano and Nakagiri [H. Sano, S. Nakagiri, Stabilization of a coupled transport-diffusion system with boundary input, J. Math. Anal. Appl. 363 (2010) 57-72], we treated the stabilization problem for the case with Neumann boundary control and distributed observation. The novelty of this paper is the formulation of the boundary observation equation in a Hilbert space. We have an interesting result of its being expressed by using an A(1)(gamma)-bounded operator with gamma epsilon (1/2, 1). Moreover, it is shown that a reduced-order model with a finite-dimensional state variable is controllable and observable. This means that one can always construct a finite-dimensional stabilizing controller for the original infinite-dimensional system by using a residual mode filter (RMF) approach. (c) 2010 Elsevier Inc. All rights reserved.
ACADEMIC PRESS INC ELSEVIER SCIENCE, May 2011, JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS, 377 (2), 807 - 816, English[Refereed]
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We consider the problem of stabilizing a coupled transport-diffusion system with boundary input. The system is described by two linear transport-diffusion equations and is not asymptotically stable. In order to stabilize the system with boundary input, sensor influence functions are assumed to be located at interior of the domain. First, we formulate the system as an evolution equation with unbounded output operators in a Hilbert space, using variable transformation. Next, we derive a reduced-order model with a finite-dimensional state variable for the infinite-dimensional system. Then, a stabilizing controller is constructed for the reduced-order model under an additional assumption. It is shown that the finite-dimensional controller together with a residual mode filter plays a role of a finite-dimensional stabilizing controller for the original infinite-dimensional system, if the order of the residual mode filter is chosen sufficiently large. Finally, the validity of the design method is demonstrated through a numerical simulation. (C) 2009 Elsevier Inc. All rights reserved.
ACADEMIC PRESS INC ELSEVIER SCIENCE, Mar. 2010, JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS, 363 (1), 57 - 72, English[Refereed]
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This paper is concerned with the observability problem of a parallel-flow two-fluid heat exchanger equation with diffusion term. First, the case where two fluid temperatures are measured it the outlet is considered. It is shown that, the observed system with the measurements becomes observable oil any interval of time through a concrete series expression of the solution. Next, the two cases where each one of two fluid temperatures is measured at, the outlet, are considered. It is also shown that the observed system with the only one measurement, becomes observable on any interval of time except for the special cases of physical constant's appearing in the equation. For the exceptional cases the unobservable subspace is finite dimensional and is characterized by using the eigenfunctions of heat equation with fluid transfer term.
JAPAN ACAD, May 2009, PROCEEDINGS OF THE JAPAN ACADEMY SERIES A-MATHEMATICAL SCIENCES, 85 (5), 61 - 66, English[Refereed]
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In this paper, we treat feedback control of parallel-flow heat exchanger equations with distributed and boundary inputs. As the distributed inputs to the system, the output feedback control is first applied under zero boundary inputs. Then, it is shown that the C-0-semigroup describing the closed-loop system satisfies the spectrum determined growth condition. Next, we apply a forwardstepping method to the design of the boundary inputs. Our main result shows that, for any initial data belonging to a linear space, the solution of the system becomes zero in finite time under both the output feedback control and the control law derived by the forwardstepping method.
WORLD SCIENTIFIC AND ENGINEERING ACAD AND SOC, 2009, RECENT ADVANCES IN APPLIED MATHEMATICS, 1, 106-111, 106 - +, English[Refereed]
International conference proceedings
We consider a feedback control problem of first-order coupled hyperbolic partial integro-differential equations with distributed and boundary inputs. As the distributed inputs to the system, the output feedback control is first applied under zero boundary inputs. Then, we apply a backstepping method to the design of the boundary inputs. Our main result shows that, for any initial data belonging to a linear space, the solution of the system becomes zero in finite time under both the output feedback control and the control law derived by the backstepping method. Further, the exact formula of feedback solutions is presented. Two applications to the parallel-flow heat exchange equations and the reactor equations of plug-flow type are given.
WORLD SCIENTIFIC AND ENGINEERING ACAD AND SOC, 2009, RECENT ADVANCES IN APPLIED MATHEMATICS, 1, 112-119, 112 - +, English[Refereed]
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In this paper, we treat the problem of stabilizing a flexible cable with two rigid loads which is described by two kinds of hyperbolic equations. From the engineering point of view, the model can be regarded as a distributed parameter overhead crane which conveys two loads simultaneously. In this, the mass of the cart is assumed to be not zero. After deriving a control law which does not increase an energy defined for the model, we prove the asymptotic stability of the closed-loop system by using the LaSalle's invariance principle. The stabilization problem is also discussed for the case of the system with one rigid load.
OXFORD UNIV PRESS, Sep. 2008, IMA JOURNAL OF MATHEMATICAL CONTROL AND INFORMATION, 25 (3), 353 - 366, English[Refereed]
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This paper is concerned with the dynamical analysis of parallel-flow heat exchanger equations with observation at the outlet of tube/control at the inlet of tube. The parallel-flow heat exchanger equation is super-stable under zero boundary condition. The system can be described by an unbounded operator of lower triangular form through a variable transformation. By calculating a Co-semigroup generated by the operator, it is shown that the system is observable if both fluid temperatures are measured at the outlet, and that the system is observable with respect to the non-negative cone of the state space if either of them is measured at the outlet. Moreover, it is shown that the system is reachable if both fluid temperatures are controlled at the inlet, and that the system is reachable with respect to the non-negative cone of the state space if either of them is controlled at the inlet.
OXFORD UNIV PRESS, Mar. 2007, IMA JOURNAL OF MATHEMATICAL CONTROL AND INFORMATION, 24 (1), 137 - 147, English[Refereed]
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This paper is concerned with the problem of reachability of parallel-flow heat exchanger equations with boundary inputs. It is shown that the system with boundary inputs is formulated as a boundary control system which is well-defined in the sense of Curtain and Zwart (1995), and further that it is reachable through a concrete expression of the solution. In addition, the reachable subspace is given for the case where only one boundary input is added to the system.
JAPAN ACAD, Jan. 2007, PROCEEDINGS OF THE JAPAN ACADEMY SERIES A-MATHEMATICAL SCIENCES, 83 (1), 1 - 4, English[Refereed]
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In this paper, we study the stabilization problem of a flexible cable with two rigid loads which is described by two kinds of hyperbolic equations. From the engineering point of view, the model can be regarded as a distributed parameter overhead crane which conveys two loads simultaneously. After deriving a control law which does not increase an energy defined for the model, we prove the asymptotic stability of the closed-loop system, using the LaSalle's invariance principle. Finally, we show that the control law works effectively through a numerical simulation.
KINOKUNIYA CO LTD, Oct. 2006, JAPAN JOURNAL OF INDUSTRIAL AND APPLIED MATHEMATICS, 23 (3), 225 - 237, English[Refereed]
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In this note, we treat a linear bioprocess model with recycle loop and analyze the spectrum of the closed-loop operator in order to discuss the exponential stability. It is shown that a C-0-semigroup generated by the closed-loop operator satisfies the spectrum determined growth assumption and that the recycle loop works effectively for the process through a numerical simulation.
IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, Aug. 2005, IEEE TRANSACTIONS ON AUTOMATIC CONTROL, 50 (8), 1200 - 1205, English[Refereed]
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This paper is concerned with stability analysis of a mono-tubular heat exchanger equation with static output feedback. The mono-tubular heat exchanger equation is exponentially stable when the input variable is identically zero. In this paper, it is shown that the C-0-semigroup generated by the closed-loop operator consisting of the mono-tubular heat exchanger equation and the output feedback law satisfies the spectrum determined growth assumption. (C) 2003 Elsevier B.V. All rights reserved.
ELSEVIER SCIENCE BV, Dec. 2003, SYSTEMS & CONTROL LETTERS, 50 (5), 363 - 369, English[Refereed]
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This paper is concerned with boundary control of a linear distributed parameter bioprocess. Huang's result (Ann. Differential Equations 1(1) (1985) 43) on the spectrum determined growth assumption is applied to prove that the closed-loop system becomes exponentially stable under a certain condition with respect to the feedback gain. Moreover, it is shown that the decay rate of the open-loop system is given by letting the feedback gain tend to zero. (C) 2003 The Franklin Institute. Published by Elsevier Science Ltd. All rights reserved.
PERGAMON-ELSEVIER SCIENCE LTD, Aug. 2003, JOURNAL OF THE FRANKLIN INSTITUTE-ENGINEERING AND APPLIED MATHEMATICS, 340 (5), 293 - 306, English[Refereed]
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An H-infinity control problem with measurement feedback for infinite-dimensional discrete-time (IDDT) systems whose homogeneous parts are described by Riesz-spectra operators is considered. The aim is to construct a finite-dimensional stabilizing controller for the IDDT system that makes the H-infinity norm of the closed-loop transfer function less than a given positive number delta. For that purpose, we first formulate the IDDT system as an IDDT system in l(2) and derive a finite-dimensional reduced-order system for the IDDT system in l(2). A stabilizing controller that makes the H-infinity norm of the closed-loop transfer function less than another positive number is then constructed for the reduced-order model. The finite-dimensional controller together with a residual mode filter plays a role of a finite-dimensional stabilizing controller that makes the H-infinity norm of the closed-loop transfer function less than delta for the original IDDT system, if the order of the residual mode filter is chosen sufficiently large.
TAYLOR & FRANCIS LTD, Feb. 2003, INTERNATIONAL JOURNAL OF SYSTEMS SCIENCE, 34 (3), 205 - 214, English[Refereed]
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In this paper, we consider H∞ control problem with measurement feedback for flexible beam equation systems. The aim is to construct a finite-dimensional H∞ controller with a given level δ for the flexible beam equation system. For that purpose, we first formulate the system as an infinite-dimensional system in l2 and derive a finite-dimensional reduced-order system for the infinite-dimensional system. Then, an H∞ controller with level d less than δ is constructed for the reduced-order model. The finite-dimensional controller together with a residual mode filter plays a role of a finite-dimensional H∞ controller with level δ for the original flexible beam equation system, if the order of the residual mode filter is chosen sufficiently large.
Dec. 2002, IMA Journal of Mathematical Control and Information, 19 (4), 477 - 491, English[Refereed]
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In this paper, we study H-infinity control of linear parabolic systems with unbounded output operators. Our aim is to construct a finite-dimensional stabilizing controller for the linear parabolic system that makes the H-infinity norm of the closed-loop transfer function less than a given positive number delta. To this end, we first derive a finite-dimensional reduced-order system for the linear parabolic system. Then, for the reduced-order model, we construct a stabilizing controller that makes the H-infinity norm of the closed-loop transfer function less than another positive number. It is proved that the finite-dimensional controller together with a residual mode filter plays a role of a finite-dimensional stabilizing controller that makes the H-infinity norm of the closed-loop transfer function less than delta for the original linear parabolic system, if the order of residual mode filter is chosen sufficiently large.
TAYLOR & FRANCIS LTD, Nov. 1999, INTERNATIONAL JOURNAL OF CONTROL, 72 (16), 1466 - 1479, English[Refereed]
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In this paper, we consider H-infinity control of linear and semilinear diffusion systems by using a finite-dimensional controller. The main aim is to construct a finite-dimensional stabilizing controller for the linear diffusion system that makes the H-infinity norm of the closed-loop transfer function less than a given positive number delta. For that purpose, we first derive a finite-dimensional reduced-order system for the linear diffusion system. Then, a stabilizing controller that makes the H-infinity norm of the closed-loop transfer function less than another positive number is constructed for the reduced-order model. It is proved that the finite-dimensional controller, together with a residual mode filter, plays a role of a finite-dimensional stabilizing controller that makes the H-infinity norm of the closed-loop transfer function less than delta for the original linear diffusion system if the order of residual mode filter is chosen sufficiently large. Moreover, it is shown that the finite-dimensional H-infinity controller constructed for the linear diffusion system also works as a finite-dimensional H-infinity controller for a semilinear diffusion system with sufficiently small nonlinear term.
SIAM PUBLICATIONS, 1999, SIAM JOURNAL ON CONTROL AND OPTIMIZATION, 37 (2), 409 - 428, English[Refereed]
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The stabilization problem of infinite-dimensional systems with periodically time-varying bounded input and unbounded output operators is considered. The unboundedness of the periodically time-varying ouput operators is assumed to be A(gamma)-bounded. For example, the systems contain linear diffusion systems with boundary control and observation, where the actuator and sensor influence functions periodically vary with respect to the time variable. The aim of this paper is to show that a controller, which consists of a finite dimensional stabilizing controller constructed for the finite-dimensional reduced-order modal model and a residual mode filter, works as a finite-dimensional stabilizing controller for the original infinite-dimensional system if the order of residual mode filter is chosen to be sufficiently large.
TAYLOR & FRANCIS LTD, Jun. 1998, INTERNATIONAL JOURNAL OF SYSTEMS SCIENCE, 29 (6), 643 - 651, English[Refereed]
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This paper investigates the exponential stability of a model of a heat exchanger of counterflow type, whose boundary conditions are governed by boundary feedbacks. A theorem by F. L. Huang is applied to prove that the system satisfies the spectrum-determined growth assumption.
Oxford University Press, 1998, IMA Journal of Mathematical Control and Information, 15 (4), 317 - 330, English[Refereed]
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rn this paper, we consider H-infinity control of infinite-dimensional linear time-varying (IDLTV) systems whose homogeneous parts are of modal type, by using a finite-dimensional controller. The aim is to construct a finite-dimensional stabilizing controller for the IDLTV system that makes the norm of the closed-loop operator less than a given positive number delta. To this end, a finite-dimensional model is firstly derived for the IDLTV system, and a stabilizing controller that makes the norm of the closed-loop operator less than another positive number gamma(<delta) is constructed for the finite-dimensional model. Then it is shown that a controller, which consists of a residual mode filter and the controller mentioned above, becomes a finite-dimensional stabilizing controller for the given IDLTV system such that the closed-loop operator has norm less than delta, if the order of the residual mode filter is chosen sufficiently large. (C) 1997 Academic Press.
ACADEMIC PRESS INC, Dec. 1997, JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS, 216 (2), 667 - 684, English[Refereed]
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This paper deals with an application of inertial manifold theory to boundary stabilization of semilinear diffusion systems on a one-dimensional domain. It is shown that a Sakawa type of controller plays an important role in the construction of an inertial manifold for the closed-loop system with a given semilinear diffusion system. This means that the use of a Sakawa type of controller reduces the stabilization problem for the closed-loop system to the one on the inertial manifold. (C) 1995 Academic Press, Inc.
ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS, Nov. 1995, JOURNAL OF MATHEMATICAL ANALYSIS AND APPLICATIONS, 196 (1), 18 - 42, English[Refereed]
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This paper is concerned with the stabilization problem of infinite-dimensional systems with A(gamma)-bounded output operators. An operator is said to be A(gamma)-bounded if it can be written as C(A + c)(gamma) for some bounded operator C and some scalar c (see [1]). For example, the linear diffusion system with distributed (or boundary) control and boundary observation is formulated as an evolution equation with bounded input operator and A(gamma)-bounded output operator in a Hilbert space. The purpose of this paper is to show that the closed-loop system with a finite-dimensional controller containing residual mode filter, which Balas introduced for infinite-dimensional systems with bounded input and output operators, is exponentially stable if the order of residual mode filter is chosen sufficiently large.
PERGAMON-ELSEVIER SCIENCE LTD, Sep. 1994, APPLIED MATHEMATICS LETTERS, 7 (5), 17 - 22, English[Refereed]
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The stabilization of semi-linear parabolic distributed systems by means of boundary controls is treated, formulating the partial differential equation describing the system as an evolution equation in a Hilbert space. Here, by using the properties of an analytic semigroup, the global existence of the solution under static output feedback is shown. Moreover, in the similar way, the global existence of the solution and the stabilizability for the system which installs a finite dimensional dynamic compensator is shown.
TAYLOR & FRANCIS LTD, Aug. 1994, INTERNATIONAL JOURNAL OF CONTROL, 60 (2), 243 - 263, English[Refereed]
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This paper deals with the stabilization of semilinear parabolic distributed systems by means of boundary controls. The partial differential equation describing the system is formulated as a semilinear evolution equation in a Hilbert space by using a variable transformation. Here it is shown that the solution globally exists for the closed-loop system which installs a finite-dimensional dynamic compensator by using the properties of an analytic semigroup. Moreover, a sufficient condition for stabilization of the system is derived by making use of the modified Gronwall's inequality developed in this paper.
ELSEVIER SCIENCE BV, Feb. 1994, SYSTEMS & CONTROL LETTERS, 22 (2), 145 - 156, English[Refereed]
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An approach via inertial-manifold theory is presented as a way to study the problem of stabilizing semilinear diffusion systems using finite-dimensional controllers. It is shown that a Sakawa type of controller plays an important role in the construction of an inertial manifold for the closed-loop (controlled) semilinear diffusion system. This means that the use of a Sakawa type of controller reduces the stabilization problem for the closed-loop system to the one on the inertial manifold. © 1994 Oxford University Press.
1994, IMA Journal of Mathematical Control and Information, 11 (1), 75 - 92, English[Refereed]
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Oral presentation
Oral presentation
Oral presentation
Oral presentation
Oral presentation
Oral presentation
The Institute of Systems, Control and Information Engineers
The Society of Instrument and Control Engineers
The Mathematical Society of Japan
The Japan Society for Industrial and Applied Mathematics
システム制御情報学会
日本数学会
計測自動制御学会
日本応用数理学会
Competitive research funding
Competitive research funding
Competitive research funding
Competitive research funding
Competitive research funding
Competitive research funding
Competitive research funding
Competitive research funding