Details of a Researcher - Namerikawa, Toru

Papers - Namerikawa, Toru

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Multiple Cooperative Bilateral Teleoperation with Time-Varying Delay

Nam Duc Do, Yusuke Yamashina, and Toru Namerikawa

SICE Journal of Control, Measurement, and System Integration (The Society of Instrument and Control Engineers) 4 ( 2 ) 89-96 - 96 2011.05

Research paper (scientific journal), Single Work, Accepted, ISSN 1882-4889

10911940390420110430155646PDF1.pdf

Robotic Mapping and Localization Considering Unknown Noise Statistics

Hamzah Ahmad and Toru Namerikawa

Journal of System Design and Dynamics (The Japan Society of Mechanical Engineers) 5 ( 1 ) 70-82 - 82 2011.01

Research paper (scientific journal), Single Work, Accepted, ISSN 1881-3046

This paper presents an analysis of H∞ Filter(HF) for Robotics Mapping and Localization with unknown noise statistics. HF which is also known as the minimax filter is proposed in this paper to estimate the robot and landmarks location while robot moves through an unknown environment. Some of the conditions are proposed to ensure that the state covariance in HF is converging to a steady state value. Furthermore, the analysis of HF convergence for a robot observing landmarks are presented to examine its behavior through the observations. From the experimental results, HF gives a sufficient estimation about the environment. Subsequently, such a result can provide other available estimation methods with the capability to ensure and improved estimation in robotic mapping and localization problem.

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Intermittent measurement in robotic localization and mapping with FIM statistical bounds

Ahmad Hamzah, Namerikawa Toru

IEEJ Transactions on Electronics, Information and Systems 131 ( 6 ) 1223 - 1232 2011

Research paper (scientific journal), Joint Work, Accepted, ISSN 0385-4221

The focus of study is to review the FIM statistical behavior in each EKF update and determine its potential in providing sufficient information about Robotic Localization and Mapping problem with intermittent measurements. We provide theoretical analysis and prove that the FIM can successfully describe both upper and lower bounds for the state covariance matrix whenever measurement data is not arrived during robot observations. This approach can give a better picture on how information are processed in EKF when measurement data is partially unavailable. Some simulation evaluations are also included to verify our results and consistently demonstrate the expected outcome. © 2011 The Institute of Electrical Engineers of Japan.

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Cooperative Control Based on Force-Reflection with Four-channel Teleoperation System

Nam Duc Do, Toru Namerikawa

2011 50TH IEEE CONFERENCE ON DECISION AND CONTROL AND EUROPEAN CONTROL CONFERENCE (CDC-ECC) (IEEE) 4879 - 4884 2011

Accepted

This paper focuses on a new Force-Reflection (FR) algorithm based on input-to-state stability (ISS) small gain theorem in cooperative work of Single Master-Multiple Slave (SMMS) teleoperation system with time varying communication delay. In this work, we propose a new position tracking control for object grasping and a new FR algorithm based on a PD control to transfer the positions, velocities and force information between both sides of teleoperation. The goals of these methods are to achieve the secure grasping by multiple slave robots and improve the tracking performance of the cooperation SMMS teleoperation system. To analyze stability of the system, the ISS small gain approach is used to show the overall force-reflecting teleoperation to be input-to-state stable. Several experimental results show the effectiveness of our proposed method.

Distributed Load Frequency Control of Electrical Power Networks via Iterative Gradient Methods

Toru Namerikawa, Taichiro Kato

2011 50TH IEEE CONFERENCE ON DECISION AND CONTROL AND EUROPEAN CONTROL CONFERENCE (CDC-ECC) (IEEE) 7723 - 7728 2011

Accepted

This paper discusses a distributed control for load frequency of electrical power networks based on iterative gradient methods. The control objective is to minimize the quadratic cost function of load frequency control problem, and we apply the distributed control methodology by using iterative gradient methods to complicated large scale electrical power networks. Iterative gradient methods have good flexibility and they are effective for complicated and time-varying distributed power networks. Several numerical simulation results of distributed power network systems including distributed generations, batteries, and renewable energies in order to show the effectiveness of the load frequency control compared with conventional decentralized control and centralized control.

Predictive Control and Estimation for Systems with Information Structured Constraints

Toru Namerikawa, Takeshi Hatanaka, Masayuki Fujita

2011 11TH INTERNATIONAL CONFERENCE ON CONTROL, AUTOMATION AND SYSTEMS (ICCAS) (IEEE) Vol. 4 ( No. 6 ) 538 - 543 2011

Accepted

This paper deals with a predictive control and estimation problem with information structured constraints in a constrained finite-time optimal control framework. A large-scale system with information structures is defined as a system in which each subsystem collects spatio-temporally different information, and in general it is necessary to collect and process information in a distributed fashion. We propose a novel predictive control scheme and an estimation law with local information that each distributed subsystem obtains. The effectiveness of the proposed control and estimation law is evaluated through numerical simulations of a simplified micro grid.

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Control Theory for Energy and Environment Problems

Toru Namerikawa

2010 IEEE Multi-conference on Systems and Control (The Institute of Electrical and Electronics Engineers (IEEE)) 2010.09

Four-channel force-reflecting teleoperation with impedance control

Do Nam Duc, Namerikawa Toru

International Journal of Advanced Mechatronic Systems 2 ( 5-6 ) 318 - 329 2010

Research paper (scientific journal), Joint Work, ISSN 1756-8412

This paper focuses on a bilateral control of teleoperation system with four-channel force-reflection (FR) algorithm and communication time delays. In this method, we propose a new system input of impedance control that relates to FR scheme of teleoperation. The goal of this paper is to improve the tracking performance and transparency, the control-based force-reflecting teleoperation uses a force feed forward channel in comparison with a conventional method to transfer the position, velocity and human force information from the master side to the slave side. Hence, we receive a four-channel architecture of the teleoperation system. Using variable damping values, the contact stability is achieved at the time when the slave robot contacts with the environment. To analyse stability of the system, one method based on Lyapunov technique is concerned, the input-to-state stability (ISS) small gain approach is used to show the overall force-reflecting teleoperation to be input-to-state stable. Several experimental results show the effectiveness of our proposed algorithm. © 2010 Inderscience Enterprises Ltd.

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Bilateral Teleoperation of Multiple Cooperative Robots with Time-Varying Delay

Nam Duc Do, Yusuke Yamashina, Toru Namerikawa

2010 IEEE INTERNATIONAL CONFERENCE ON CONTROL APPLICATIONS (IEEE) 2053 - 2058 2010

Accepted, ISSN 1085-1992

This paper deals with a passive-decomposition based control of bilateral teleoperation between a single master robot and multiple cooperative slave robots under time varying delay in the communication line. At first, we decompose the dynamics of multiple slave robots into two decoupled dynamics: the Shape-System describing dynamics of the cooperative works, and the Locked-System representing overall behavior of the multiple slave robots. Second, we propose a PD control method for bilateral teleoperation to guarantee the asymptotical stability of the system for time varying delay. Finally, experimental results show the effectiveness of our proposed teleoperation.

Sensor Network Scheduling Algorithm Considering Estimation Error Variance and Communication Energy

Takashi Takeda, Toru Namerikawa

2010 IEEE INTERNATIONAL CONFERENCE ON CONTROL APPLICATIONS (IEEE) 434 - 439 2010

Accepted, ISSN 1085-1992

This paper deals with a sensor scheduling algrithm considering estimation error variance and communication energy in sensor networked feedback systems. We propose a novel decentralized estimation algorithm with unknown inputs in each sensor node. Most existing works deal with the sensor network systems as sensing systems and it is difficult to apply them to the real physical feedback control systems Then some local estimates are merged and the merged estimates can be optimized in the proposed method and the estimation error covariance has a unique positive definite solution under some assumptions. Next, we propose a novel sensor scheduling algorithm in which each sensor node transmits information. A sensor node uses energy by communication between other sensor node or the plant. The proposed algorithm achieves a sub-optimal network topology with minimum energy and a desired variance. Experimental results show an effectiveness of the proposed method.

Robot Localization and Mapping Problem with Unknown Noise Characteristics

Hamzah Ahmad, Toru Namerikawa

2010 IEEE INTERNATIONAL CONFERENCE ON CONTROL APPLICATIONS (IEEE) 1275 - 1280 2010

Accepted, ISSN 1085-1992

In this paper, we examine the H-infinity Filter-based SLAM especially about its convergence properties. In contrast to Kalman Filter approach that considers zero mean gaussian noise, H-infinity Filter is more robust and may provide sufficient solutions for SLAM in an environment with unknown statistical behavior. Due to this advantage, H-infinity Filter is proposed in this paper, to efficiently estimate the robot and landmarks location under worst case situations. H-infinity Filter requires the designer to appropriately choose the noise's covariance with respect to gamma to obtain a desired outcome. We show some of the conditions to be satisfy in order to achieve better estimation results than Kalman Filter. From the experimental results, H-infinity Filter performs better than Kalman Filter for a case of bigger robot initial uncertainties. Subsequently, this proved that H-infinity Filter can provide another available estimation method for especially in SLAM.

Bilateral Teleoperation of Wheeled Mobile Robot with Time Delay using Virtual Image Robot.

Yasunori Kawai, Toru Namerikawa, Masayuki Fujita

Proceedings of the IEEE International Conference on Control Applications, CCA 2010, Yokohama, Japan, September 8-10, 2010 (IEEE) 77 - 82 2010

Accepted

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Network-Topology Independent Cooperative Target-enclosing Behavior by Swarms of Vehicles

KAWAKAMI Hiroki and Namerikawa Toru

Transactions of the Society of Instrument and Control Engineers (The Society of Instrument and Control Engineers) 45 ( 12 ) 688-695 2009.12

Research paper (conference, symposium, etc.), Joint Work, Accepted

This paper deals with cooperative target-enclosing problem for swarms of vehicles with dynamic network-topology.
First, we introduce a dynamic network topology that depends on relative distance between the vehicles.
Secondly, we propose the target-enclosing strategy based on consensus seeking with dynamic network-topology.
In proposed strategy, at least one vehicle has to acquire the states of target-object. Furthermore, we prove that
convergence speed of each vehicle is independent of network-topology. To analyze the convergence of target-enclosing
behavior under dynamic network topology, algebraic graph theory and matrix theory are utilized.
Finally, numerical simulation results and experimental results are provided that demonstrate the effectiveness of
the proposed method.

Consensus Problem for Multi-Agent Systems and Cooperative Capturing Behavior

Toru Namerikawa

Systems, Control and Information (The Institute of Systems, Control and Information Engineers) 53 ( 10 ) 443-448 - 448 2009.10

Research paper (scientific journal), Single Work

複数の対象が協調して作業を行うマルチエージェントに関しては，これまでにも議論されているが，近年グラフ理論とシステム制御理論の融合からのアプローチが注目を集めています．
本稿では，マルチエージェントの合意問題に対し，意制御則の設計法と情報結合構造について解説し，更にビークルフォーメーションとビークル群による協調取り囲み行動などの応用について紹介する．

Delay-Independent Stabilization of Teleoperation Systems with Time-Varying Delay

Hiroyuki FUJITAand Toru Namerikawa

SICE Journal of Control, Measurement, and System Integration (The Society of Instrument and Control Engineers) 2 ( 3 ) 177–183 - 183 2009.05

Research paper (conference, symposium, etc.), Joint Work, Accepted, ISSN 1882-4889

This paper deals with stability of nonlinear teleoperation systems with time-varying communication delays.
The proposed method is the use of passivity-based controllers with time-varying gains which depend on the rate of
change of time-varying delay. In our proposed method, the stability condition is independent of the magnitude of the
communication delay and the damping of the system. The delay-independent stability is shown via Lyapunov stability
methods. Several experimental results show the effectiveness of our proposed teleoperation structure.

Robust stabilization of running self-sustaining two-wheeled vehicle with varying speed and mass variations

Satoh Hiroshi, Namerikawa Toru

Nihon Kikai Gakkai Ronbunshu, C Hen/Transactions of the Japan Society of Mechanical Engineers, Part C (Japan Society of Mechanical Engineers) 75 ( 752 ) 882 - 889 2009.04

Research paper (scientific journal), Accepted, ISSN 0387-5024

This paper deals with robust stabilization of running self-sustaining two-wheeled vehicle with varying running speed and mass variations. Recently, there have been a lot of research results about stabilization of two-wheeled vehicle. These researches have achieved the stable running only by the steering control. However, an actual two-wheeled vehicle is stabilized by not only the steering control, but the control of a vehicle's center of gravity. We have proposed the stabilization control method of two-wheeled vehicle in the state of stillness, and have shown the effectiveness of proposed approach. In this research, we construct the control system for the running stabilization of two-wheeled vehicle. H^∞ control problem is used to design the controller to achieve running stability even if the running speed and the mass of two-wheeled vehicle would change. The experimental results show effectiveness of proposed approach for robustness.

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速度と質量の変動に対する自立走行二輪車のロバスト安定化

佐藤拓史, 滑川徹

日本機械学会論文集, C編 (日本機械学会) 75 ( 752 ) 882-889 2009.04

Research paper (scientific journal), Joint Work

本研究では静止状態において安定化させる目的で開発した自立走行二輪車に対して，走行安定化を目的とした制御系を構成する．走行を考慮したモデリングを行い，導出した数学モデルが静止時の場合の拡張となっていることを確認した．二輪車の走行速度と質量の変動を考慮した制御系をH∞制御系設計問題を用いて設計し，実際に走行速度を変動した場合と，付加質量を搭載した場合においても安定化が実現できた．これにより，速度変動や質量変動に対して提案するロバスト姿勢制御系の有効性が確認された．

Bilateral Control of Nonlinear Teleoperation with Time Varying Delays

Hisanosuke Kawada and Toru Namerikawa

Transactions of the Society of Instrument and Control Engineers (Society of Instrument and Control Engineers) 45 ( 1 ) 18-26 2009.01

Research paper (conference, symposium, etc.), Joint Work, Accepted

This paper addresses the bilateral control of nonlinear teleoperation with time varying delays. The proposed
control strategies are two types of simple PD-type controllers which directly connect the master and slave robots by position and velocity signals over the delayed communication. For the velocity control, the first controller has a time varying D-gains which depend on the rate of change of delays and the second one has a constant
D-gains which are designed under stability condition. Moreover the both controllers have explicit position feedback/feedforward control. Using Lyapunov-Krasovskii function, the delay-depend stability of the origin is shown
for the range of the gains. Furthermore the proposed framework enforces master-slave position coordination
and static force reflection. Several simulation and experimental results show the effectiveness of our proposed
framework.

10911937617020100411175258PDF1.pdf

GIMC structure based Anti-Windup control considering L2 performance

Nakashima Yusuke, Namerikawa Toru

Proceedings of the IEEE International Conference on Control Applications (IEEE = Institute of Electrical and Electronics Engineers) ( 5281047 ) 956 - 961 2009.01

ISSN 1085-1992

This paper deals with GIMC (Generalized Internal Model Control) structure based Anti-Windup (AW) control system design. First, we setup a L2 performance criterion based on GIMC structure for Anti-Windup control problems. The design problem is formulated as an optimization problem with a parameter Q. Then we calculate the optimization problem and find an optimal Q. Finally, the effectiveness of proposed method is shown by experimental results for a magnetic suspension system. © 2009 IEEE.

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2008 American Control Conference -ACC 2008-

NAMERIKAWA Toru

システム/制御/情報 53 ( 1 ) 48 2009.01

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