Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Fuji Technology Press Ltd.  

<p>In this study, we propose a novel tailsitter unmanned aerial vehicle with configurable wings using a parallel link mechanism. It has two flight modes: a hover mode and a forward flight mode by pitching, similar to conventional tailsitters. In addition, it can deform its airframe in each flight mode. In the hover mode, it can tilt the frame in the pitch direction while hovering. In the forward flight mode, it can change the configuration of the wings during forward flight. In experiments, we show that it can transition from the hover mode to the forward flight mode with three wing configurations: non-staggered wings (biplane) and positively and negatively staggered wings (tandem wing plane), using an attitude controller for conventional quadrotors.</p>

DOI： 10.20965/jrm.2024.p1037

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Fuji Technology Press Ltd.  

<p>This study investigates the problem of distributed state estimation. A distributed Kalman filter algorithm is proposed, in which sensors exchange their innovations. A detailed analysis is conducted for the case of two sensor networks, demonstrating that the proposed algorithm outperforms the case where each sensor runs a conventional Kalman filter without communication. The upper bounds of error covariance matrices are also derived in the case of packet loss. Numerical examples verify the effectiveness of the proposed algorithm.</p>

DOI： 10.20965/jrm.2024.p0680

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Other Link： https://www.fujipress.jp/jrm/rb/robot003600030680/

Repository Public URL： https://hdl.handle.net/2324/7339174

Authorship：Lead author,　Corresponding author  

DOI： 10.1109/MCS.2024.3382374

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Authorship：Last author,　Corresponding author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：Advanced Robotics  

We present a novel approach that employs nonlinear model predictive control (NMPC) to address flock control while incorporating obstacle avoidance within a leader-follower framework. This strategy utilises each agent's predictive capabilities to navigate effectively. Building upon Reynolds' foundational flocking principles of cohesion, separation, and alignment, we adapt them to serve a navigation objective rather than focusing solely on formation tasks. In doing so, we introduce novel concepts that enhance our approach's robustness and flexibility. These concepts include the assessment of information credibility and significance received from neighbouring agents, along with the dynamic adjustment of trade-offs between reference values. We incorporate these features into our NMPC formulation and illustrate their advantages through numerical simulations and laboratory experiments.

DOI： 10.1080/01691864.2023.2299859

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

Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)   Publisher：The Institute of Systems, Control and Information Engineers  

DOI： 10.11509/sci.sci24.0_586

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Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)   Publisher：The Japan Joint Automatic Control Conference  

DOI： 10.11511/jacc.67.0_379

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Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：THE INSTITUTE OF SYSTEMS, CONTROL AND INFORMATION ENGINEERS (ISCIE)  

<p>We study the problem of optimal route generation for visiting measurement points in seismic surveys. For this purpose, we consider the employment of multiple drones to install seismometers at the measurement points. An algorithm combining fuzzy clustering and the traveling salesman problem is proposed to generate an energy-efficient path for each drone. Several practical conditions typically arising in this application are also taken into account.</p>

DOI： 10.5687/iscie.36.181

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical Electronics Engineers（IEEE）  

This work examines the generation and transmission expansion planning problem of offshore grids under different market clearing mechanisms: a home market design, a zonally cleared offshore bidding zone and a nodally cleared offshore bidding zone. It aims at answering two questions. Is knowing the market structure a priori necessary for effective generation and transmission expansion planning? And which market mechanism results in the highest overall social welfare? To this end, a multi-period, stochastic generation and transmission expansion planning formulation is developed for both nodal and zonal market designs. The approach considers the costs and benefits among stake-holders of hybrid offshore assets as well as gross consumer surplus. The methodology is demonstrated on a North Sea test grid based on projects from the European network of transmission system operators’ ten-year network development plan. An upper bound on potential social welfare in zonal market designs is calculated and it is concluded that from a generation and transmission perspective, knowing the market structure a priori is not strictly necessary but planning under the assumption of a nodal offshore bidding zone is recommended as it results in the highest overall social welfare and best risk adjusted return.

CiNii Research

Other Link： https://arxiv.org/abs/2301.00931

Authorship：Lead author,　Corresponding author   Language：Japanese  

Steering a fleet of vehicles with nonlinear MPC: flocking model and distributed control

Repository Public URL： https://hdl.handle.net/2324/7339173

Language：Japanese   Publisher：システム制御情報学会  

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Fuji Technology Press Ltd.  

<p>In this study, we investigate the problem of finding energy-efficient routes for multiple drones conducting a surface-wave seismic survey. The survey utilizes one seismic source and multiple measurement points spread over a designated area. Each drone carries a seismometer, and is tasked with visiting pre-specified points to take measurements of seismic signals by resting idle on the ground for a set time. Due to this mandatory idling time, their energy consumption is not proportional to the flight distance, nor it is possible to apply standard path minimization algorithms. To address this issue, we establish an energy consumption model for each drone and propose algorithms to optimally allocate points to each drone and generate routes that minimize total energy consumption. The validity of these algorithms is discussed using numerical simulations.</p>

DOI： 10.20965/jrm.2023.p0271

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Repository Public URL： https://hdl.handle.net/2324/6791127

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

DOI： https://doi.org/10.1016/j.ifacol.2023.10.840

Repository Public URL： https://hdl.handle.net/2324/7170224

Language：Japanese  

Connectivity in mobile robot networks

Language：Japanese   Publisher：システム制御情報学会  

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Authorship：Last author   Language：English   Publishing type：Research paper (scientific journal)   Publisher：The Japan Joint Automatic Control Conference  

DOI： 10.11511/jacc.66.0_396

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

This work examines the Generation and Transmission Expansion (GATE) planning problem of offshore grids under different market clearing mechanisms: a Home Market Design (HMD), a zonal cleared Offshore Bidding Zone (zOBZ) and a nodal cleared Offshore Bidding Zone (nOBZ). It aims at answering two questions. 1) Is knowing the market structure a priori necessary for effective generation and transmission expansion planning? 2) Which market mechanism results in the highest overall social welfare? To this end a multi-period, stochastic GATE planning formulation is developed for both nodal and zonal market designs. The approach considers the costs and benefits among stake-holders of Hybrid Offshore Assets (HOA) as well as gross consumer surplus (GCS). The methodology is demonstrated on a North Sea test grid based on projects from the European Network of Transmission System Operators' (ENTSO-E) Ten Year Network Development Plan (TYNDP). An upper bound on potential social welfare in zonal market designs is calculated and it is concluded that from a generation and transmission perspective, planning under the assumption of an nOBZ results in the best risk adjusted return.

DOI： 10.48550/ARXIV.2301.00931

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Authorship：Last author   Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)   Publisher：The Japan Joint Automatic Control Conference  

DOI： 10.11511/jacc.66.0_201

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：Proceedings of the IEEE Conference on Decision and Control  

This paper studies the relation between node deletion and algebraic connectivity for graphs with a hierarchical structure represented by layers. To capture this structure, the concepts of layered path graph and its (sub)graph cone are introduced. The problem is motivated by a mobile robot formation control guided by a leader. In particular, we consider a scenario in which robots may leave the network resulting in the removal of the nodes and the associated edges. We show that the existence of at least one neighbor in the upper layer is crucial for the algebraic connectivity not to deteriorate by node deletion.

DOI： 10.1109/CDC51059.2022.9992940

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Repository Public URL： https://hdl.handle.net/2324/6790819

Language：Others   Publishing type：Research paper (international conference proceedings)   Publisher：Institute of Electrical and Electronics Engineers: IEEE  

We propose a model predictive control (MPC) based approach to a flock control problem with obstacle avoidance capability in a leader-follower framework, utilizing the future trajectory prediction computed by each agent. We employ the traditional Reynolds' flocking rules (cohesion, separation, and alignment) as a basis, and tailor the model to fit a navigation (as opposed to formation) purpose. In particular, we introduce several concepts such as the credibility and the importance of the gathered information from neighbors, and dynamic trade-offs between references. They are based on the observations that near-future predictions are more reliable, agents closer to leaders are implicit carriers of more educated information, and the predominance of either cohesion or alignment is dictated by the distance between the agent and its neighbors. These features are incorporated in the MPC formulation, and their advantages are discussed through numerical simulations.

DOI： 10.1109/CCTA49430.2022.9966067

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CiNii Research

Repository Public URL： https://hdl.handle.net/2324/6625739

Language：Japanese   Publishing type：Research paper (other academic)   Publisher：The Japan Joint Automatic Control Conference  

Deadlock avoidance for robot navigation with potential field method in an unknown environment

DOI： 10.11511/jacc.65.0_8

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Other Link： https://www.jstage.jst.go.jp/article/jacc/65/0/65_8/_article/-char/en

Repository Public URL： https://hdl.handle.net/2324/6632465

Language：Japanese   Publishing type：Research paper (other academic)   Publisher：The Japan Joint Automatic Control Conference  

Smooth merging for autonomous vehicles by centralized control

DOI： 10.11511/jacc.65.0_588

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Other Link： https://www.jstage.jst.go.jp/article/jacc/65/0/65_588/_article/-char/en

Repository Public URL： https://hdl.handle.net/2324/6791125

Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

We propose a novel quadrotor with a 3-axis deformable frame using parallel link modules. By adding three servo motors to the frame, it has two configurations, namely, roll-pitch deformation mode and yaw deformation mode. In the roll-pitch deformation mode, it can tilt and fold the frame in the roll and pitch directions independently, which gives it 6 controllable degrees of freedom (CDOF). In the yaw deformation mode, it can contract the whole frame in the yaw direction. We propose a design method without thrust loss at any deformed state in both modes. In experiments, we show that it can fly stably even when deformed in both modes by the extended conventional control method. Furthermore, its applications are presented to demonstrate its high versatility.

DOI： 10.1109/LRA.2022.3191195

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Language：Others   Publishing type：Research paper (scientific journal)   Publisher：Institute of Electrical and Electronics Engineers ({IEEE})  

A large AC loss is generated in armature windings composed of a REBa2Cu3Oy (REBCO, RE = rare earth, Eu, Gd, etc.) wire in a fully superconducting synchronous generator. In aircraft applications, liquid nitrogen is suitable for cooling windings because of its specific heat capacity and dielectric strength. The evaporation of liquid refrigerant significantly decreases the dielectric strength, which results in an increase in the risk of accidents by discharging. For safe operation, the temperature in the generator is set below the boiling point of nitrogen (∼77 K). We calculated the temperature rise caused by the AC loss and others by applying a method that estimates the AC loss from the experimental results. This paper addresses the electromagnetic-thermal analysis in finite element method to calculate the temperature rise and proves the feasibility of a fully superconducting generator cooled by liquid nitrogen, that is, the temperature is maintained below 77 K. The output power is 10 MW. The temperature of liquid nitrogen was assumed to be 65 K, and its flow speed was set as a parameter. Additionally, we confirmed that designing a method that determines the number of parallel conductors of REBCO windings considering the temperature rise can enhance the output power density.

DOI： 10.1109/TASC.2022.3160660

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Language：Japanese   Publishing type：Research paper (other academic)  

Multiple drone route optimization for a seismic survey

Authorship：Corresponding author   Language：Japanese   Publishing type：Research paper (conference, symposium, etc.)   Publisher：システム制御情報学会  

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Language：Japanese   Publishing type：Research paper (other academic)  

Smooth obstacle avoidance for mobile robots using pure-pursuit algorithms

Other Link： https://www.jstage.jst.go.jp/article/jacc/64/0/64_746/_article/-char/en

Repository Public URL： https://hdl.handle.net/2324/6791124

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

DOI： 10.1109/TASC.2021.3055452

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

Towards Next Generation Mobility and Sustainable Society

DOI： 10.11499/sicejl.60.509

Other Link： https://www.jstage.jst.go.jp/article/sicejl/60/7/60_509/_article/-char/en

Repository Public URL： https://hdl.handle.net/2324/6790815

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

DOI： 10.1016/j.ifacol.2021.06.064

Repository Public URL： http://hdl.handle.net/2324/4785187

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

DOI： 10.1177/09596518211004303

Repository Public URL： http://hdl.handle.net/2324/4785190

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

DOI： 10.1109/TASC.2020.2974705

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

DOI： 10.1109/TASC.2020.2989746

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

DOI： 10.1109/TASC.2020.2971671

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

DOI： 10.21820/23987073.2020.2.6

Repository Public URL： http://hdl.handle.net/2324/4785183

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

Towards Flexible and Robust Networks

DOI： 10.11499/sicejl.58.741

Other Link： https://www.jstage.jst.go.jp/article/sicejl/58/10/58_741/_article/-char/en

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

Conceptual design and electromagnetic analysis of superconducting induction motors using REBa2Cu3Oy tapes

DOI： 10.11527/jceeek.2019.0_31

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

Cooling Property of 1kW Fully-superconducting Synchronous Motor with REBa₂Cu₃O_y Wires

DOI： 10.11527/jceeek.2019.0_32

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

DOI： 10.23919/ECC.2019.8795985

Repository Public URL： http://hdl.handle.net/2324/4785154

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

DOI： 10.1109/CDC.2018.8619614

Repository Public URL： http://hdl.handle.net/2324/4785151

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

DOI： 10.1109/CDC.2018.8619555

Repository Public URL： http://hdl.handle.net/2324/4785200

Language：Japanese  

My Journey of Research－Cambridge, Minnesota and Lund

DOI： 10.11509/isciesci.62.11_466

Other Link： https://www.jstage.jst.go.jp/article/isciesci/62/11/62_466/_article/-char/en

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

DOI： 10.1007/s10915-018-0696-8

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

DOI： 10.23919/ACC.2018.8431273

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

DOI： 10.1007/978-3-319-67068-3_27

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

DOI： 10.1109/CDC.2017.8264601

Repository Public URL： http://hdl.handle.net/2324/4784752

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

DOI： 10.1109/CCTA.2017.8062611

Repository Public URL： http://hdl.handle.net/2324/4784751

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

DOI： 10.1016/j.ifacol.2017.08.559

Repository Public URL： http://hdl.handle.net/2324/4784749

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

DOI： 10.1109/CDC.2016.7798875

Repository Public URL： http://hdl.handle.net/2324/4784741

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

Other Link： https://iopscience.iop.org/article/10.1088/1742-6596/744/1/012063

Repository Public URL： http://hdl.handle.net/2324/4784739

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

DOI： 10.1109/CDC.2013.6759855

Repository Public URL： http://hdl.handle.net/2324/4784734

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

DOI： 10.1002/tal.539

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

H^∞ Optimization in Damper Placement for Interstory Control of Bending-shear Building Model

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

DOI： 10.1016/j.scs.2010.08.002

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

Optimal Damper Placement in Building Structures for H^∞ Norm

DOI： 10.3130/aijs.75.2163

Repository Public URL： https://hdl.handle.net/2324/6791126

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

H^∞ Optimization in Damper Placement for Interstory-drift and Acceleration Control of Building Structures

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

Optimal Damper Placement for Minimum Interstorey-drift Transfer Function

Language：Japanese  

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

DOI： 10.12989/eas.2010.1.3.289

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

Repository Public URL： https://hdl.handle.net/2324/6791123

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

Uncertainty Analysis of Base-isolated Buildings with Uncertain Base-isolation Systems

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

Uncertainty Analysis of Base-isolated Buildings with Uncertain Base-isolation Systems

Event date： 2023.3

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

Venue：立命館大学 びわこ・くさつキャンパス   Country：Japan  

Event date： 2023.3

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

Venue：立命館大学 びわこ・くさつキャンパス   Country：Japan  

Event date： 2022.12

Language：English   Presentation type：Oral presentation (general)  

Venue：Cancun   Country：Mexico  

Event date： 2022.12

Language：English  

Venue：Cancun   Country：Mexico  

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Event date： 2022.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇都宮   Country：Japan  

Event date： 2022.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：宇都宮   Country：Japan  

Event date： 2022.11

Language：Japanese  

Venue：宇都宮   Country：Japan  

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Event date： 2022.11

Language：Japanese  

Venue：宇都宮   Country：Japan  

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Event date： 2022.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Trieste   Country：Italy  

Event date： 2022.8

Language：English   Presentation type：Oral presentation (general)  

Venue：Trieste   Country：Italy  

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Event date： 2022.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都リサーチパーク   Country：Japan  

Event date： 2022.5

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：京都リサーチパーク   Country：Japan  

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Event date： 2021.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.11

Language：Japanese   Presentation type：Oral presentation (general)  

Venue：オンライン   Country：Japan  

Event date： 2021.3

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2019.6

Language：English  

Venue：Naples   Country：Italy  

We study the disturbance attenuation problem in a heterogeneous mass chain where both the number of masses and the mass distribution may change. The paper studies the scalar transfer functions from the disturbance at a boundary point to a given intermass displacement. It is shown that these transfer functions can be represented in the form of composition sequences generated by Möbius transformations. The framework aims at devising a method of designing the interconnection impedances in the mass chain in a scale-free manner. That is, the resulting design guarantees certain performance criteria for mass chains of any length and any mass distribution. A graphical method is provided for such an interconnection design problem.

Event date： 2019.3

Language：Japanese  

Country：Japan  

Event date： 2018.12

Language：English  

Venue：Miami   Country：United States  

This paper studies the problem of reconstructing continuous-time signals from discrete-time uniformly sampled data. This signal reconstruction problem has been studied by the authors in various contexts, and led to a new signal processing paradigm. The key idea there is to employ a physically realizable signal generator model, and design an (sub)optimal filter via H^ infty(mathbb C- +) optimal sampled-data control theory. The present paper aims at extending this framework to a more general setting where observed data are acquired through an acquisition device (prefilter) that has compact support. In this way, the framework can capture the properties of processing signals with a localized acquisition filter. We give a general setup as well as approximate solution methods along with their convergence results. A simulation is presented to illustrate some properties of the result.

Event date： 2018.12

Language：English  

Venue：Miami   Country：United States  

We present two sensitivity function trade-offs that apply to a class of networks with a string topology. In particular we show that a lower bound on the H-infinity norm and a Bode sensitivity relation hold for an entire family of sensitivity functions associated with growing the network. The trade-offs we identify are a direct consequence of growing the network, and can be used to explain why poorly regulated low frequency behaviours emerge in long vehicle platoons even when using dynamic feedback.

Event date： 2018.8

Language：Japanese   Presentation type：Oral presentation (general)  

Country：Japan  

Event date： 2018.7

Language：English  

Country：Japan  

This note studies the disturbance amplification in an interconnected heterogeneous mass chain in which one end is connected to a movable point. Each interconnection is represented by a general mechanical impedance function. The problem arises in the design of multi-storey buildings subjected to earthquake disturbances, or bidirectional control of vehicle platoons. Recurrence relations with respect to the number of masses are derived for the scalar transfer functions from the movable point displacement to a given intermass displacement. In particular, each relation takes the form of a Moebius transformation.

Event date： 2018.6

Language：English  

Venue：Milwauke   Country：United States  

We give a method for designing a mechanical impedance to suppress the propagation of disturbances along a chain of masses. The key feature of our method is that it is scale free. This means that it can be used to give a single, fixed, design, with provable performance guarantees in mass chains of any length. We illustrate the approach by designing a bidirectional control law in a vehicle platoon in a manner that is independent of the number of vehicles in the platoon.

Event date： 2017.12

Language：English  

Venue：Melbourne   Country：Australia  

This paper studies the problem of reconstructing continuous-Time signals from discrete-Time uniformly sampled data. This signal reconstruction problem has been studied by the authors in various contexts, and led to a new signal processing paradigm. The crux there is to employ a physically realizable signal generator model, and design an (sub)optimal filter via H^TC(C₊) optimal sampled-data control theory. The present paper extends this framework to the situation where sampling is more general having a generalized sampling kernel. It is more consistent with a more general framework, for example, wavelet signal expansion, and can lead to a more general applications. We give a general setup along with a solution via fast-sample/fast-hold approximation. A simulation is presented to illustrate the result.

Event date： 2017.8

Language：English  

Venue：Kohala Coast   Country：United States  

This paper studies the disturbance rejection problem for sampled-data control systems, where disturbance signal occurs below and above the Nyquist frequency simultaneously. Two discrete-time controllers are designed via H^∞ optimal control in two steps; at first a controller is designed to reject the low-frequency components, and then we construct the generalized plant including the first controller to design the second controller, which has the capability of rejecting the high-frequency components. In view of the well-known sampling theorem, one recognizes that any high-frequency components may be detected only as an alias in the low base band, and hence it is impossible to recover or detect such frequency components. The authors recently showed in [13] that this assumption depends crucially on the underlying analog model, and it is indeed possible to track or reject such frequency components by introducing multirate signal processing techniques. This paper aims to make this design technique applicable to the case in which the target frequencies lie both below and above the Nyquist frequency. Detailed analysis of multirate closed-loop systems are given. It is shown via examples that rejection of lower- and higher-frequency signals than the Nyquist frequency can be achieved.

Event date： 2016.12

Language：English  

Venue：Las Vegas   Country：United States  

This paper studies the problem of tracking or disturbance rejection for sampled-data control systems, where the tracking signal can have frequency components higher than the Nyquist frequency. In view of the well-known sampling theorem, one recognizes that any high-frequency components may be detected only as an alias in the low base band, and hence it is impossible to recover or detect such frequency components. This paper examines the basic underlying assumption, and shows that this assumption depends crucially on the underlying analog model. We show that it is indeed possible to recover such high-frequency signals, and also that, by introducing multirate signal processing techniques, it is possible to track or reject such frequency components. Detailed analysis of multirate closed-loop systems and zeros and poles are given. It is shown via examples that tracking of high-frequency signals beyond the Nyquist frequency can be achieved with satisfactory accuracy.

Event date： 2016.7

Language：English  

Venue：Southampton   Country：United Kingdom  

This paper studies the problem of passive control of a multi-storey building subjected to an earthquake disturbance. The building is represented as a homogeneous mass chain model, i.e., a chain of identical masses in which there is an identical passive connection between neighbouring masses and a similar connection to a movable point. The paper considers passive interconnections of the most general type, which may require the use of inerters in addition to springs and dampers. It is shown that the scalar transfer functions from the disturbance to a given inter-storey drift can be represented as complex iterative maps. Using these expressions, two graphical approaches are proposed: one gives a method to achieve a prescribed value for the uniform boundedness of these transfer functions independent of the length of the mass chain, and the other is for a fixed length of the mass chain. A case study is presented to demonstrate the effectiveness of the proposed techniques using a 10-storey building model. The disturbance suppression performance of the designed interconnection is also verified for a 10-storey building model which has a different stiffness distribution but with the same undamped first natural frequency as the homogeneous model.

Event date： 2013.12

Language：English  

Venue：Florence   Country：Italy  

This paper introduces the problem of passive control of a chain of N identical masses in which there is an identical passive connection between neighbouring masses and a similar connection to a movable point. The problem arises in the design of multi-storey buildings which are subjected to earthquake disturbances, but applies in other situations, for example vehicle platoons. The paper will study the scalar transfer functions from the disturbance to a given intermass displacement. It will be shown that these transfer functions can be conveniently represented in the form of complex iterative maps and that these maps provide a method to establish boundedness in N of the H _∞-norm of these transfer functions for certain choices of interconnection impedance.

Event date： 2010.7

Language：Japanese  

Country：Other  

20185 H^∞ Optimization in Damper Placement for Interstory-drift and Acceleration Control of Building Structures

Event date： 2010.7

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2009.7

Language：Japanese  

Country：Other  

Uncertainty Analysis of Base-isolated Buildings with Uncertain Base-isolation Systems

Event date： 2009.7

Language：Japanese   Presentation type：Oral presentation (general)  

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Event date： 2009.5

Language：Japanese  

Country：Other  

Uncertainty Analysis of Base-isolated Buildings with Uncertain Base-isolation Systems

Event date： 2009.5

Language：Japanese   Presentation type：Oral presentation (general)  

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Language：English   Presentation type：Oral presentation (general)  

Venue：Berlin, Germany (Online)   Country：Other  

Language：Japanese   Publisher：The Society of Instrument and Control Engineers  

DOI： 10.11499/sicejl.61.451

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Language：Japanese  

DOI： https://doi.org/10.11499/sicejl.58.741

Other Link： https://doi.org/10.11499/sicejl.58.741

Language：Japanese  

DOI： 10.11509/isciesci.62.11_466

Language：Japanese  

Language：Japanese  

21458 Uncertainty Analysis of Base-isolated Buildings with Uncertain Base-isolation Systems

Language：Japanese  

2011 Uncertainty Analysis of Base-isolated Buildings with Uncertain Base-isolation Systems

Type：Competition, symposium, etc. 

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Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

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Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

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Type：Peer review 

Number of peer-reviewed articles in foreign language journals：5

Proceedings of International Conference Number of peer-reviewed papers：21

Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

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Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

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Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

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Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

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Type：Peer review 

Number of peer-reviewed articles in foreign language journals：7

Proceedings of International Conference Number of peer-reviewed papers：15

Type：Academic society, research group, etc. 

Type：Peer review 

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Type：Peer review 

Number of peer-reviewed articles in foreign language journals：7

Proceedings of International Conference Number of peer-reviewed papers：5

Type：Academic society, research group, etc. 

Type：Academic society, research group, etc. 

Type：Peer review 

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Type：Competition, symposium, etc. 

Type：Competition, symposium, etc. 

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：3

Number of peer-reviewed articles in Japanese journals：1

Proceedings of International Conference Number of peer-reviewed papers：1

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：4

Proceedings of International Conference Number of peer-reviewed papers：6

Type：Peer review 

Number of peer-reviewed articles in foreign language journals：3

Proceedings of International Conference Number of peer-reviewed papers：6

Audience：General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Lecture

Audience：Infants,　Schoolchildren,　Junior students,　High school students

Type：Seminar, workshop

Type：Seminar, workshop

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Type：Lecture

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Audience：General,　Scientific,　Company,　Civic organization,　Governmental agency

Type：Lecture

海外大学院でのPhD取得およびその後の海外での研究活動における自身の経験をもとに，研究や日常生活，その他について紹介する．

Type：Lecture

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Audience：Infants,　Schoolchildren,　Junior students,　High school students

Type：Seminar, workshop

Type：Seminar, workshop

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