Language：English   Publishing type：Research paper (international conference proceedings)  

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Language：English   Publishing type：Research paper (international conference proceedings)  

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Authorship：Lead author,　Corresponding author   Language：English   Publishing type：Research paper (international conference proceedings)  

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical Engineers of Japan (IEE Japan)  

DOI： 10.1541/ieejeiss.138.263

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

An approach to control-oriented uncertainty modeling is presented for a class of elastic vibrating systems such as flexible structures, beams and strings, described by partial differential equations. Uncertainty bounding techniques are developed using the upper and lower bounds of the unknown eigenparameters. The result forms a basis for a finite-dimensional controller design in which closed loop stability and performance are guaranteed. A feasible set of systems is defined of all systems governed by a class of differential equations with certain norm bounds of the unknown input and output operators and with partially known bounds of the eigenparameters. Then the perturbation magnitude covering the feasible set is evaluated in the frequency domain where a standard truncated modal model is chosen as the nominal one. An upper bound to the truncated error magnitude which is calculated by linear programming is proposed. It is demonstrated that all the parameters formulating a feasible set are derived by finite element analysis for a flexible beam example, and feasibility of the proposed scheme is also illustrated by numerical bounding results. (c) 2006 Wiley Periodicals, Inc.

DOI： 10.1002/eej.20272

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Authorship：Lead author   Language：English  

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Language：English   Publishing type：Research paper (scientific journal)  

An approach to control-oriented uncertainty modeling is presented for a class of elastic vibrating systems such as flexible structures, beams and strings, described by partial differential equations. Uncertainty bounding techniques are developed using upper and lower bounds of the unknown eigenparameters. The result forms a basis for a finite-dimensional controller design in which closed loop stability and performance are guaranteed. A feasible set of systems is defined of all systems governed by a class of differential equations with certain norm bounds of unknown input and output operators and with partially known bounds of eigenparameters. Then the perturbation magnitude covering the feasible set is evaluated in frequency domain where a standard truncated modal model is chosen as the nominal one. An upper bound to the truncated error magnitude is proposed which is calculated using linear programming. It is demonstrated that all the parameters formulating a feasible set are derived using finite element analysis for a flexible beam example, and feasibility of the proposed scheme is also illustrated by numerical bounding results. © 2005, The Institute of Electrical Engineers of Japan. All rights reserved.

DOI： 10.1541/ieejeiss.125.77

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

In this paper, we propose a distributed routing method for multiple mobile robots under uncertain motion delays. The feature of the proposed method is that each AGV subsystem creates the routing to minimize the sum of the transportation time and the penalty for collision avoidance constraints taking into account motion delay disturbances for other AGVs. The computational results show that the total transportation time obtained by the proposed method is shorter than that of the conventional method under various type of motion delay disturbances.

DOI： 10.1109/IROS.2005.1545271

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Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：IRON STEEL INST JAPAN KEIDANREN KAIKAN  

In recent years, many control systems have been developed and applied to hot rolling in order to improve the quality of the finished products. Due to the plant characteristics and the control system performance variations over time, human experts intervene and modulate control gains to maintain and to improve the control system performance. Through a breakthrough, we can expect to attain the fully automated modulation of control gains without human intervention. A neural network model representing gain modulating actions by human was developed for a looper height controller in hot strip mills. The developed neural network model is a recurrent type neural network (RNN) which calculates the appropriate PID gains of the looper height controller based on the modification data Of human operations as training data. Further, a learning algorithm for the RNN model was developed to accelerate convergence of the gain modification process and to stabilize the looper movement. The neural gain tuning model was applied to the inter-stands looper height controller in hot strip mills. The usefulness of the developed model was checked through numerical experiments. From the experimental results, it was verified that the tuning actions by humans can be realized by the model. Through its learning mechanism, the model could also cope with disturbances such as changes in roll gap. This may lead to the stabilization of threading operations of hot strip mills.

DOI： 10.2355/tetsutohagane1955.90.11_933

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

An optimal finite-dimensional modeling technique is presented for a standard class of distributed parameter systems for heat and diffusion equations. A finite-dimensional nominal model with minimum error bounds in frequency domain is established for spectral systems with partially known eigenvalues and eigenfunctions. The result is derived from a completely characterized geometric figure upon complex plane, of all the frequency responses of the systems that have (i) a finite number of given time constants T-i's and modal coefficients k(i)'s, (ii) an upper bound p to the infinite sum of the absolute values of all the modal coefficients k(i)'s, (iii) an upper bound T to the unknown T-i's, and (iv) a given dc gain G(0). Discussions are made on how each parameter mentioned above makes contribution to bounding error or uncertainty, and we stress that steady state analysis for dc input is used effectively in reduced order modeling and bounding errors. The feasibility of the presented scheme is demonstrated by a simple example of heat conduction in ideal copper rod.

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Publisher：The Society of Instrument and Control Engineers  

Route planning of multiple AGVs (Automated Guided Vehicles) is expected to minimize the transportation time without collision and deadlock among the AGVs in many transportation systems. In this paper, we propose an autonomous distributed route planning method for multiple mobile robots. The proposed method has a characteristic that each mobile robot individually creates a near optimal route through the repetitive data exchange among the robots and the local search of route using Dijkstra's algorithm. The proposed method is applied to several transportation route planning problems. The optimality of the solution generated by the proposed method is evaluated using the duality gap derived by Lagrangian relaxation method. A near optimal route plan within 5% of duality gap for a large scale transportation system consisting of 143 nodes and 15 AGVs can be obtained with five seconds of computation time by using Pentium III (1GHz) processor. Moreover, it is shown that the proposed method is effective for various types of problems despite the fact that each route for AGV is created without optimizing the entire objective function even when the velocity of each AGV is different.

DOI： 10.9746/sicetr1965.39.759

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

A control-oriented uncertainty modeling on frequency domain is presented for a class of spectral systems with unknown high-order modal parameters. At any user-specified frequency, the set of all the feasible frequency responses is characterized on the complex plane where it is said to be feasible if partial modal parameters of a system are given and the other unknown modal parameters meet certain conditions. We emphasize that such a characterization enables us to quantify the least upper bounds of errors for any nominal models, and also to develop further efficient results using additional information. It is shown in the paper that, the dc gain information of the system reduces the size of the feasible set to the half or smaller, for any frequencies. The efficiency of the presented scheme is demonstrated by a simple example of ideal flexible beam.

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

In this paper, we present a new interpretation of the subspace-based state space system identification (4SID) method by using a subspace extraction via Schur complement (SES). Several efficient implementations of subspace-based identification methods (e.g., N4SID, etc) have been thus far developed and proposed. We consider the MIMO output error state space model identification, the so-called MOESP, Making a comparison between the matrix obtained by the QR factorization in the MOESP and the Schur complement matrix of data product moments shows that the estimate of the extended observability matrix can be obtained by using the SES procedure. Viewing that fact that the Schur complement yielded by the subspace extraction coincides with the error covariance in the least squares (LS), our interpretation will pave the way for the derivation of the recursive algorithm of the 4SID method.

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

A procedure for control-oriented modeling of uncertainty is proposed for large flexible structures. Techniques on quantification of errors in modal truncated nominal models are developed for the case where a finite number of upper and lower bounds of the unknown modal parameters are given. A feasible set of systems matching the conditions is introduced, and then error bounds covering the feasible set are established in the frequency domain. The bounds are easily checked using linear programming for any user-specified frequency. The feasibility of the proposed scheme is illustrated by numerical study on an ideal flexible beam example.

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Publisher：The Society of Instrument and Control Engineers  

An approach is presented for modeling uncertainty from a priori information of a plant. A feasible model set is defined of all systems governed by a class of differential equations with certain norm bounds of unknown input and output operators and partially known eigenparameters. Then an unstructured uncertainty class of models including the feasible model set is characterized with least magnitude of additive perturbation in frequency domain. An example of finite dimensional compensator design is demonstrated to illustrate the usefulness of the approach.

DOI： 10.9746/sicetr1965.35.349

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

An approach is presented for modeling with least additive uncertainty from a priori information of a plant. A feasible set of systems is defined as the set of all systems governed by a dass of differential equation with certain norm bounds of unknown input and output operators as well as partially known eigenparameters. Then an unstructured uncertainty class including the feasible set is characterized with least magnitude of additive perturbation in frequency domain. An example of finite dimensional compensator design is demonstrated to illustrate the usefulness of the presented approach.

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Publisher：The Society of Instrument and Control Engineers  

In this paper, robust identification of discrete time systems in time domain is studied. An approach is proposed to estimate the nominal model, minimizing the errors, with iterative computation on numerator and donominator. Methods are proposed to reduce the influence of noise on the proposed scheme. Numerical study shows effectiveness of these methods for idenifying characteristics in low frequency range of systems in the presence of noise.

DOI： 10.9746/sicetr1965.34.1374

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：PERGAMON PRESS LTD  

A study is presented on relationships between subspace approaches and conventional parameter estimation schemes. We focus on identification of single-input-single-output(SISO) systems via the Subspace State Space Identification (4SID) method. We show that an intermediate vector which appears in the 4SID procedure is equal to the parameter of the system pulse transfer function if the model set includes the system with noise free measurements. We also show explicitly, in a elementary way, that the intermediate vector is also equivalent to the estimate via the eigenvector method in the case that the column size of the extended observability matrix is equal to "(the order of the model) + 1". Furthermore, we demonstrate that using a modified cost functional in the Eigenvector method corresponds to the IV-4SID method and hence gives a consistent estimate even for colored noise.

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：I E E E  

In this paper, we present a reduced order modeling technique for a stable self-adjoint spectral system with unbounded input/output operators. An uncertainty model which covers the original distributed parameter system is formulated in view of finite dimensional controller design using linear robust control theory. The model is made of a finite dimensional nominal plant and frequency domain additive error bounds. The nominal model is a modal truncation containing a feed-through term with no de errors between the nominal plant and the system. The bound is computable using elements of the system and partial knowledge of spectral structure. The formula obtained can be readily applicable to a wide class of systems including heat conduction and diffusion, and easily extended for systems with vibration.

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DOI： 10.1541/ieejeiss1987.115.7_882

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DOI： 10.5687/iscie.5.365

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Publisher：The Society of Instrument and Control Engineers  

For a parabolic distributed parameter system with boundary inputs, we consider a finite dimensional approximation scheme of Galerkin type and propose a method yielding approximation models with no static errors.<br>We illustrate a modal interpretation of the approximation model in the caseeigenfunction is employed for the coordinate function and show that the magnitude of the approximation errors of the higher order modes are proportional to the first-order differential of the system input.<br>We verify above results numerically both by simulation study in time domain and error evaluation in frequency domain, for an example of a constant parameter system.

DOI： 10.9746/sicetr1965.27.1366

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Other Link： https://jlc.jst.go.jp/DN/JALC/00012918980?from=CiNii

Publisher：Kyushu University  

DOI： 10.15017/1498359

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Event date： 2022.11.26

Language：Japanese  

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Event date： 2022.11.26

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Event date： 2022.11.26

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Event date： 2022.11.26

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Event date： 2022.11.26

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Event date： 2022.11.26

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2022.3.7 - 2022.3.10

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2021.3.1 - 2021.3.4

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2020.3.2 - 2020.3.5

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2020.1.4 - 2020.1.5

Language：Japanese   Presentation type：Symposium, workshop panel (nominated)  

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Event date： 2020

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Event date： 2020

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese  

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Language：Japanese   Presentation type：Oral presentation (general)  

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