Updated on 2025/09/30

写真a

 
西村　悠樹
 
Organization
Faculty of Environmental, Life, Natural Science and Technology Professor
Position
Professor
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Degree

  • 博士（情報科学） ( 2009.3   北海道大学 )

  • 修士（工学） ( 2005.3   北海道大学 )

Education

  • Hokkaido University   大学院情報科学研究科   システム情報科学専攻

    2005.4 - 2009.3

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  • Hokkaido University   大学院工学研究科   システム情報工学専攻

    2003.4 - 2005.3

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  • Hokkaido University   工学部   情報エレクトロニクス系システム工学科

    1998.4 - 2002.12

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Research History

  • Okayama University   学術研究院 環境生命自然科学学域（工）   Professor

    2025.4

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  • Kagoshima University   Graduate School of Science and Engineering   Associate Professor

    2012.4 - 2025.3

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  • Yamaguchi University   Graduate School of Science and Engineering   Assistant Professor

    2009.4 - 2012.3

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Papers

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Books

  • 理解しやすい制御工学

    柴田, 論, 穆, 盛林, 西村, 悠樹, 熊澤, 典良, 山本, 智規

    コロナ社  2025.5  （ ISBN:9784339032505 ）

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    Total pages：viii, 206p   Language：Japanese

    CiNii Books

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MISC

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Research Projects

  • Human assist control for safe personal mobilities

    Grant number：22H01514  2022.04 - 2025.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    中村 文一, 西村 悠樹, 佐藤 康之

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    Grant amount：\17290000 （ Direct expense: \13300000 、 Indirect expense：\3990000 ）

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  • Human assist control for safe personal mobilities

    Grant number：23K22784  2022.04 - 2025.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    中村 文一, 西村 悠樹, 佐藤 康之

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    Grant amount：\17290000 （ Direct expense: \13300000 、 Indirect expense：\3990000 ）

    自動車や船舶などの事故が大きな社会問題となる現代において，問題発生時の自動的な安全停止などリスク最小化移行技術が重要技術となってきている．本研究は，零化バリア関数を用いた，入力制約，外乱，システムのパラメータ誤差を考慮した広範囲の社会実装に耐えうる安全アシスト制御理論の構築を行い，電動車いす等への制御則を実装し実機実験によって制御理論の有効性を示すことが目的である．
    本年度は，理論的な研究成果として，入力制約を有する制御システムに対してViability Kernelに基づく厳密零化制御バリア関数を提案し，１入力の場合における制御則の連続性を示した．安全集合が閉集合，特にコンパクト集合である場合において，安全性は安全集合内の制御系の性質ではなく，安全集合外部，すなわち危険集合における制御系の性質であることを明らかにできた．また，実用安定性アシスト制御を用いた自動車のレーンキープ制御法を提案した．これらの理論的な研究成果についてはコンピュータシミュレーションにより有効性を示した．
    安全アシスト制御理論のパーソナルモビリティへの応用を考える際に，危険度の可視化は重要な技術である．本年度は，仮想入力を用いることにより，操作者に対する安全性の可視化法を開発した．また，深度センサ，RGBカメラを用いた画像提示システムの開発に成功した．
    また，本研究課題における実機実験におけるC#を用いた疑似リアルタイム制御について解説論文にまとめた．

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  • Construction of a Next-Generation Control Theory Driven by Highly-Complex Signals

    Grant number：20H02171  2020.04 - 2024.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    西村 悠樹, 佐藤 訓志, 中村 文一, 星野 健太

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    Grant amount：\17680000 （ Direct expense: \13600000 、 Indirect expense：\4080000 ）

    政府の「未来投資戦略2018」で求められている次世代モビリティや航空宇宙産業の理論的支柱であるシステム制御理論において，システムが持つ非線形性・不規則性・不連続性・高周波振動性等の複雑な性質を解析し制御設計に役立てる必要がある。本研究課題では，これら複雑な性質を高度複雑信号（ラフ信号）と捉え，その統一表現である非線形ラフシステムに基づく制御理論を提唱する。また，当該理論を電気系・ドローン・宇宙機の制御問題などに応用する。
    2021年度は2年目であったが，初年度に引き続き本研究課題の根幹部分について理論構築するとともに，実験環境を整備した。具体的には以下を実施した。
    理論面では，スライディングモード制御のように不連続特性を持つシステムのラフシステム化を開始するため、確率安定論的側面からの解析を引き続き実施した。また，非線形確率システムにおける安定論の再整理を伴うラフシステムへの本格的な拡張のため，非平滑確率リャプノフ関数や確率有限時間安定性・確率有界性についての考察を続けた。
    応用面では，電動車椅子の実験環境整備と制御のための既存結果の追実験を実施してラフ制御への糸口を探ったほか，超音波モータのラフ制御化のための有限時間整定制御を確率論をベースに検討し，サーボ制御実験を行った。そのほか，ラフ制御をするために有用と考えられる応用研究として，非線形制御理論に基づくロボットアームの衝突回避制御や船舶の軌道追従制御，非線形確率制御理論に基づくクアッドコプタの最適姿勢制御や宇宙機の姿勢制御などについて引き続き検討を続けた。

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  • Human assist control theory based on control barrier function

    Grant number：19H02162  2019.04 - 2022.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    Nakamura Hisakazu

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    Grant amount：\17420000 （ Direct expense: \13400000 、 Indirect expense：\4020000 ）

    As results of the research project, we have proposed a time-varying control barrier function and a collision avoidance control method. Moreover, we have developed a novel human assist control method which can consider shapes of control objects. Furthermore, we have proposed a strict zeroing control barrier function based. With the function, we can design a human assist control method based on zeroing control barrier functions.

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  • Construction of nonlinear stochastic robust control theory based on non-Markov model and discontinuous feedback

    Grant number：17H03282  2017.04 - 2020.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    Nishimura Yuki

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    Grant amount：\17940000 （ Direct expense: \13800000 、 Indirect expense：\4140000 ）

    Many technologies for the realization of super-smart society are generally influenced by irregular noises and vibrations. The aim of this study was to construct a stochastic stability theory for analyzing and controlling stochastic nonlinear systems, especially achieving the elimination and attenuation for irregular system noises in a practical view point. In this study, we analyzed various singular properties of stability for nonlinear stochastic systems, and then tried developing nonlinear stochastic robust control easily applied to practical systems. The validity of the proposed methods was confirmed by numerical simulation and some experimental results.

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  • Development of Control Theory for Unbounded-Variation Systems Based on Rough Path Analysis

    Grant number：16K14287  2016.04 - 2020.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Challenging Exploratory Research

    Nishimura Yuki

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    Grant amount：\3770000 （ Direct expense: \2900000 、 Indirect expense：\870000 ）

    The aim of this study was to build a basic theory of stabilization for dynamical systems driven by unbounded-variation signals, named "rough controlled systems", which are augmented systems of stochastic differential equation systems. In this study, we obtained system representations of the dynamics of rough controlled systems via rough path analysis, derived a new sufficient condition for controllability of nonlinear controlled systems influenced by unbounded-variation signals, and developing a control strategy by using correction terms, which represents the effects of unbounded-variation signals. Then, we also try extending stochastic stability analysis to rough controlled systems.

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  • Development of topological control theory for decision making

    Grant number：15H04022  2015.04 - 2018.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    Nakamura Hisakazu

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    Grant amount：\16770000 （ Direct expense: \12900000 、 Indirect expense：\3870000 ）

    This research aims to design a framework of combining decision and control from the view point of topology. The major achievements are as follows. Development of a control strategy that dynamically identifies the desired state by the minimum projection method, development of the local minimum connection method for static control Lyapunov function design, and development of a human safety assist control strategy by using control barrier functions. By the preceding achievements, this research elucidates that a control Lyapunov function and a control barrier function are effective for the combination of decision and control.

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  • Construction of nonlinear stochastic optimal control theory for attenuating system noises

    Grant number：25820184  2013.04 - 2017.03

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Young Scientists (B)

    Nishimura Yuki

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    Grant amount：\4290000 （ Direct expense: \3300000 、 Indirect expense：\990000 ）

    We derived conditions that stochastic stability for dynamical systems is not influenced by their system noises, and then proposed sufficient conditions that the trajectories of controlled systems converge to some (weak) invariant set. The forms of stochastic Lyapunov functions, ensuring stochastic asymptotic stability, are relaxed to non-differentiable in order to increase the number of stabilizable stochastic systems. The sufficient conditions for stochastic integral-input-to-state stability and almost sure bounded stability were also derived, respectively. And then, stabilization strategy for nonholonomic systems by adding Gaussian white noises was developed.

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  • Study on the nonlinear control using transformation to state-jump system

    Grant number：22360167  2010 - 2012

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (B)

    YAMASHITA Yuh, NAKAMURA Hisakazu, NISHIDA Gou, NISHIMURA Yuki, TSUZUKI Takayuki

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    Grant amount：\16770000 （ Direct expense: \12900000 、 Indirect expense：\3870000 ）

    his study proposes a framework of control system design methodologies bywhich the state space of a dynamical controlled object is extended by adding new continuous or discretecoordinates and a desired closed-loop is designed on the augmented space allowing state-jumps on thenew coordinates. Furthermore, methods of the degeneracy of the extended space for obtaining adiscontinuous static feedback law or a control law with discrete states are given. By introducingstate-jumps, we can construct a controller mathematically even for decision-making problems of thedynamical systems.

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  • Construction of nonlinear optimal control theory based on fusion of quantization methods for HJB equations and stochastic processes

    Grant number：22760320  2010 - 2012

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Young Scientists (B)

    NISHIMURA Yuki

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    Grant amount：\4160000 （ Direct expense: \3200000 、 Indirect expense：\960000 ）

    To stabilize nonlinear control systems such as nonholonomic systems, discontinuous state-feedback control laws should be designed 。 Furthermore, energy conservation measures are recently required for controlling mechanical and electrical dynamical systems。 To solve the problems at one time, this research has proposed a new numerical approximation method for nonlinear optimal regulator problems by combining two quantization methods of Hamilton-Jacobi-Bellman equations and stochastic processes。 The industrial value of the proposed method has been confirmed by the experimental researches of controlling ultrasonic motors。

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  • Establishment of nonlinear control theory taking into account global structure of manifold

    Grant number：19560435  2007 - 2009

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research  Grant-in-Aid for Scientific Research (C)

    YAMASHITA Yuh, NAKAMURA Hisakazu, NISHIDA Gou, NISHIMURA Yuki

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    Grant amount：\4420000 （ Direct expense: \3400000 、 Indirect expense：\1020000 ）

    This study presents a general framework for controlling nonlinear systems on general manifolds including non-Euclidean spaces which precedent control theories cannot handle. Global attitude control of satellites, obstacle avoidance of vehicles, and control of acrobots are examples of our problem. This framework provides design procedures generating control laws automatically with discontinuity, logic, or randomness, of which properties are necessary to stabilize such systems on non-Euclidean spaces.

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