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矢向 高弘  ヤコウ タカヒロ

教員組織電話番号
教育組織情報基盤センターFAX番号
職名特任教授メールアドレス
住所〒390-8621 長野県松本市旭3-1-1ホームページURL

プロフィール

研究分野
制御、システム工学
通信工学
機械力学、メカトロニクス
ロボティクス、知能機械システム
情報学基礎論
所属学会
所属学会
日本ロボット学会
日本機械学会
精密工学会
IEEE
学歴
出身大学院
1994 , 慶應義塾 , 理工学研究科 , 計算機科学専攻
1991 , 慶應義塾 , 理工学研究科 , 計算機科学専攻

出身学校・専攻等(大学院を除く)
1989 , 慶應義塾 , 工学部 , 計測工学科

取得学位
博士(工学) , 慶應義塾大学
受賞学術賞
2003 , ファナックFAロボット財団論文賞
研究職歴等
研究職歴
2021- , 信州大学 総合情報センター (特任教授)
2007- , 慶應義塾大学 理工学部 准教授
2009-2011 , 慶應義塾大学理工学部広報委員会幹事
2009-2011 , 慶應義塾大学理工学部システムデザイン工学科学習指導副主任
2008-2008 , ウィーン工科大学コンピュータ技術研究所、客員教授
2007-2009 , 慶應義塾大学理工学部教育計画委員会幹事
2006-2008 , 慶應義塾大学大学院理工学研究科総合デザイン工学専攻学習指導副主任
2004-2007 , 慶應義塾大学理工学部、助教授
2004-2006 , 慶應義塾大学学生総合センター矢上支部就職担当委員
2002-2004 , 東京大学非常勤講師
2001-2004 , 慶應義塾大学理工学部,専任講師
2000-2004 , 慶應義塾大学理工学部機械系計算機室 ,幹事
2000-2003 , 慶應義塾大学理工学部システムデザイン工学科 ,執行部補助
1998-2001 , 慶應義塾大学理工学部 ,助手
1996-1998 , 慶應義塾大学メディアネット本部ネットワークテクノロジーセンター(仮称)
1994-1996 , 日本鋼管株式会社情報システム部情報技術室

研究活動業績

研究業績(著書・
発表論文等)
書籍等出版物
42-47, Mn'M Workbook 3: Future Urban Intensities
フリックスタジオ 2014(Mar. 31)
Author:矢向 高弘


91-107, HUMAN – COMPUTER SYSTEMS INTERACTION: BACKGROUNDS AND APPLICATIONS 2 -Advances in Intelligent and Soft Computing-
Springer Berlin / Heidelberg 2012
Author:佐藤智矢; 境野翔; 矢向 高弘


17-32, Remote and Telerobotics
InTech 2010(May)
Author:Shinichi Hamasaki; YAKOH TAKAHIRO
Abstract:遠隔操作の操作性が通信遅延により低下してしまう問題点を、クロスモーダルな装飾により解消できる可能性があることを提案し、実験を通して検証している。


324-338, Engineering & Neuro-Psychoanalysis Forum Book
Springer-Verlag 2008(Oct.)
Author:Charlotte Roesener; Tobias Deutsch; Roland Lang Brit Muller; YAKOH TAKAHIRO
Abstract:工学と脳神経科学の境界領域の開拓を目指したフォーラムが査読論文を編纂したものであり、我々は脳の認知行動のモデル化や、シミュレータ構築、挙動に関する考察を記している。


数理工学基礎シリーズ「コンピュータの数理」
朝倉書店 2000(Oct.)
Author:矢向高弘; 村上俊之; 大西公平
Abstract:コンピュータのハードウェアの基礎から、2進数による数値計算法、C言語によるプログラミング、計算誤差にまで言及した工学者向けの教科書である。


データベースシステム概論 原書6版
丸善 1997(Mar.)
Author:藤原譲監訳
Abstract:データベースシステムの産みの親であるC. J. Dateが執筆した原典を和訳したものであり、特に関係型データベースと数学的集合論との対応付けが行われている。


論文
Real-Time Survey of Vaccine Safety of the mRNA-1273 SARS-CoV-2 Vaccine in Workplace Vaccination at Keio University
Vaccines 2022(Sep. 03)
Author:Kaho Okumura; Azusa Hara; Isa Inada; Daisuke Sugiyama; Takahiro Hoshino; Takahiro Yakoh; Hirokazu Yokoyama; Hisashi Urushihara


Re-shooting Resistant Blind Watermarking Framework Based on Feature Separation With Gaussian Mixture Model
IEEJ Transactions on Electrical and Electronic Engineering,17(4) 2022
Author:Yakoh, T.; Oi, M.


An NLP-Inspired Data Augmentation Method for Adverse Event Prediction Using an Imbalanced Healthcare Dataset
IEEE Access,10:81166-81176 2022
Author:Tomoki Ishikawa; Takahiro Yakoh; Hisashi Urushihara


Saliency Prediction based on Object Recognition and Gaze Analysis
IEEJ Transactions on Electronics, Information and Systems,141(1):76-84 2021(Jan. 01)
Author:Ishikawa T; Yakoh T
Abstract:Predicting the human visual attention in an image is called saliency prediction, and is an active research area in the field of neuroscience and computer vision. Early works on saliency prediction was performed by using low-level features. In recent years, convolutional neural networks (CNN) have been adapted for saliency prediction and achieved the state-of-the-art performance. However, the eye-gaze depends on the personality of each viewer and conventional methods did not take into account such individual properties of the viewer. Therefore, this paper proposes a novel saliency prediction method considering the influence of eye-gaze. Assuming that personality can be expressed as the degree of attention to an object, our proposed method considers the personality by learning which objects are likely to be perceived by each viewer, and weighting the universal saliency map with the generated mask based on the object detection results. The experimental results show that the proposed universal saliency map achieves higher accuracy than conventional methods on the public dataset, and the proposed weighted saliency map can reflect the variation of the eye-gaze influences among viewers. (1)


Saliency prediction based on object recognition and gaze analysis
Electronics and Communications in Japan 2021
Author:Ishikawa T; Yakoh T
Abstract:Predicting the human visual attention in an image is called saliency prediction and is an active research area in the field of neuroscience and computer vision. Early works on saliency prediction was performed by using low-level features. In recent years, convolutional neural networks have been adapted for saliency prediction and achieved the state-of-the-art performance. However, the eye-gaze depends on the personality of each viewer and conventional methods did not take into account such individual properties of the viewer. Therefore, this paper proposes a novel saliency prediction method considering the influence of eye-gaze. Assuming that personality can be expressed as the degree of attention to an object, our proposed method considers the personality by learning which objects are likely to be perceived by each viewer and weighting the universal saliency map with the generated mask based on the object detection results. The experimental results show that the proposed universal saliency map achieves higher accuracy than conventional methods on the public dataset, and the proposed weighted saliency map can reflect the variation of the eye-gaze influences among viewers.


A precise time synchronization method for real-time schedulers
Electronics and Communications in Japan,101(12):21-29 2018(Dec.)
Author:Kikutani T; Yakoh T
Abstract:This paper proposed a precise time synchronization method between schedulers of real-time operating systems by communicating time stamps over a network. An NTP-based communication protocol was used to measure the time offset between nodes. To minimize the measurement error, a light-weight network stack called RT-Messenger was used instead of common transmission control protocol/Internet protocol (TCP/IP) stack. Also, a Kalman filter was introduced to eliminate such error and to estimate time offset and drift. Furthermore, a real-time scheduler in RTAI/Linux (where RTAI is real-time application interface) was modified to compensate the time difference using the estimated offset and drift. The time compensation of a scheduler clock affects the next resume times for real-time tasks. Therefore, a recalculation process of next resume times for all real-time tasks and a reordering process of real-time task queue were added to the real-time scheduler. To validate the proposed method, time differences of resume times for two real-time tasks on different nodes were measured under various experimental conditions. The results confirm that the resume time differences were successfully kept lower than 400 ns with 300 ns standard deviation under the condition of observation period at 1 s and correction period at 10 s.


Frame transmission time control for TDMA-based ethernet
IEEE International Workshop on Factory Communication Systems - Proceedings, WFCS,2018-June:1-8 2018(Jul. 03)
Author:Hagino N; Yamamoto M; Yakoh T
Abstract:Processes of network-based control system require accurate timing control of frame transmission. A special network interface card (NIC) was proposed and implemented to adjust the timing accurately based on a dual queue structure and precise time synchronization mechanism in this paper. A high resolution measurement tool for frame transmission latency was also developed to validate the implementation. The measured results verified that the proposed NIC achieved the latency shorter than 790 ns and the deviation of it less than 49 ns while a commercial off-the-shelf NIC showed the latency longer than 9700 ns and the deviation of it more than 300 ns.


Position and velocity measurement method from a single image using modulated illumination
Proceedings - 2018 IEEE 15th International Workshop on Advanced Motion Control, AMC 2018,:353-358 2018(Mar. 10)
Author:Matsuo K; Yakoh T
Abstract:Visual feedback systems utilize position and velocity information estimated from frames captured by a camera. Since the velocity information is derrived through pseudo differential with two consecutive frames, the information must be delayed essentially, and the delay often limits the performance of visual feedback systems. To eliminate the delay, this paper proposed a novel technique to estimate position and velocity information from a single image. By detecting the start and end points of the motion blur of a target object in an image, the velocity information during the exposure time of the image can be estimated fundamentally. To tag such a temporal information on motion blurs, a modulated illumination was employed. This tagging method aimed to make motion blur detection robust against various background scenery. Some simulation results validated the feasibility of the proposed method.


Implementation of schedule management mechanism for S-TDMA switch
Proceedings - 2018 IEEE 15th International Workshop on Advanced Motion Control, AMC 2018,:575-580 2018(Mar. 09)
Author:Koyasu S; Yakoh T
Abstract:Recently, because of the development of industrial systems and network systems, the demands of telehaptics and telesurgery become higher. To realize these systems, a real-time communication which can guarantee deterministic delays and low jitters in a network is required. One of the real-time protocol is Synchronous-Time Division Multiple Access (S-TDMA). S-TDMA makes it possible to coexist of real-time and conventional TCP/IP communications over a multiple-hop network using Ethernet. In previous works, the schedule of real-time combinations was fixed. So this research introduces management mechanism of communication schedules by using the technology of Software Defined Networking (SDN). SDN is a notion to realize a dynamic and centralized control of network configuration by using one controller which can manage all equipments in the network. In this paper, the design and implementation of management mechanism of S-TDMA switches are discussed and performance of the implemented switches is verified. The experiment results confirm that it is possible to change time slot allocation, communication mode and paths dynamically. Results also show that the management system can control multiple switches in the network.


A precise time synchronization method for real-time schedulers
IEEJ Transactions on Electronics, Information and Systems,138(6):695-702 2018
Author:Kikutani T; Yakoh T
Abstract:This paper proposed a precise time synchronization method between schedulers of real-time operating systems by communicating timestamps over a network. An NTP based communication protocol was used to measure the time offset between nodes. To minimize the measurement error, a light-weight network stack called RT-Messenger was used instead of common TCP/IP stack. Also, a Kalman filter was introduced to eliminate such error and to estimate time offset and drift. Furthermore, a real-time scheduler in RTAI/Linux was modified to compensate the time difference using the estimated offset and drift. The time compensation of a scheduler clock affects the next resume times for realtime tasks. Therefore, a re-calculation process of next resume times for all real-time tasks and a re-ordering process of reak-time task queue were added into the real-time scheduler. To validate the proposed method, time differences of resume times for two real-time tasks on different nodes were measured under various experimental conditions. The results confirm that the resume time differences were successfully kept lower than 400 ns with 300 ns standard deviation under the condition of observation period at 1 s and correction period at 10 s.


無線マルチホップ通信の確率的性能予測手法
電気学会論文誌C,137(5):701-708 2017
Author:森静奈; 矢向高弘
Abstract:M2M (machine-to-machine) is required and spreads rapidly in recent years. Wireless multi-hop communication is one of the communication styles to construct M2M. However, the performance estimation of such wireless multi-hop communication is not so easy because the bit error ratio and symbol rate adaptation heavily depend on various environmental conditions. Stochastic network calculus (SNC) is a theory for the performance estimation of network. However, current SNC lacks ways to take wireless random errors, branching and joining of traffic flows into calculation, these are necessary to estimate the performance of sink-tree wireless-sensor network. This paper proposed a performance estimation method for sink-tree wireless multi-hop network based on SNC. The proposed method has three attractive points. Firstly, this introduces parameters of hop number and node number considering wireless random error due to packet collision. Secondly, this treats actual sink-tree network model by considering joining of traffic. Thirdly, this separates the service curve and bounding function calculation to avoid double counting. To evaluate the accuracy of the result of the proposed method, conventional estimation methods and simulation evaluation were conducted on a typical wireless multi-hop sensor data collection network. The results validate that the proposed method achieves much higher-accuracy than conventional methods.


Integration of Existing Ethernet Devices into Time-Division-Multiplexing Ethernet
2017 IEEE INTERNATIONAL CONFERENCE ON INDUSTRIAL TECHNOLOGY (ICIT),:1171-1176 2017
Author:Masaaki Yamamoto; Yakoh Takahiro
Abstract:Along with the development of industrial systems, real-time Ethernet (RTE) is widely utilized for control systems. S-TDMA is one of the RTE protocols, and it is a concept realizing a coexistence of real-time and best-effort communication over the Ethernet by time-division multiplexing. In previous work, a special switching hub capable of S-TDMA was implemented, and the capability of real-time communication on multi-hop topology was shown. It is expected to apply S-TDMA for the Internet; it is not practical that all nodes in the network support S-TDMA. Therefore, this paper proposes the integration method of existing Ethernet devices into S-TDMA network by using a pause frame. The performance of best-effort traffic between these devices over S-TDMA network was evaluated. The results verify the superiority of the proposed method. The proposed design greatly suppressed the performance deterioration of best-effort traffic. The throughput of the proposed method was 670 Mbps higher than that of the previous implementation at the effective bandwidth of 950 Mbps. The results also show the comparable performance, even if the number of hops has increased.


Selective Sending Block Determination Method Based on Quad-Tree Structure for Live Video Streaming System
情報処理学会第78回全国大会講演論文集,3:279-280 2016(Mar. 10)
Author:張寧; H矢向 高弘; HR


感覚提示の有効性の検証を目的とした遠隔作業環境の実装
情報処理学会第78回全国大会講演論文集,3:221-222 2016(Mar. 10)
Author:吉原大輔; 矢向 高弘


OpenFlowプロトコルを応用したS-TDMAスイッチの管理機構の実装
情報処理学会第78回全国大会講演論文集,3:205-206 2016(Mar. 10)
Author:山田佳史; 矢向 高弘


S-TDMAスイッチングハブの実装とその評価
情報処理学会第78回全国大会講演論文集,3:203-204 2016(Mar. 10)
Author:太田原香菜; 矢向 高弘


データリンク層の周期的な途絶がTCPのスループットに与える影響
情報処理学会第78回全国大会講演論文集,3:201-202 2016(Mar. 10)
Author:唐土慶太; 矢向 高弘


Performance Evaluation of TCP/IP over Time-Division Multiplexing Ethernet
PROCEEDINGS OF THE IECON 2016 - 42ND ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY,:4689-4694 2016
Author:Kana Otawara; Masaaki Yamamoto; Takahiro Yakoh
Abstract:S-TDMA is a concept to realize coexistence of RT (real-time) and non-RT traffic over switched Ethernet by separating them in a time-slot basis. Theoretically, coexistence is achieved even in multi-hop network if precise time synchronization among the all nodes on its communication path. However, since it is technically difficult, the construction of wide-area S-TDMA network was not yet achieved. This paper implemented S-TDMA switch on NetFPGA-1G-CML board with 1 Gbps Ethernet PHY, newly adding a few nanoseconds-level time synchronization and change mode mechanism to the previously presented implementation. Remarkably, this implementation enabled to examine the degree of throughput deterioration of non-RT with change-mode in one S-TDMA switch. Previous works regarding S-TDMA switch have never researched this issue. From the result of 1 ms period, TCP throughput was 14.65 Mbps when non-RT time-slot occupies 90% of each period. It was the worst value and only 4% of the result when non-RT time-slot occupies 100%. Such value is considered not practical if S-TDMA network is constructed in the real Internet infrastructure. Thus, further approaches to enhance TCP performance are discussed.


Stochastic Network Calculusを用いた スマートグリッド環境下のエンドツーエンド遅延分析
第58回自動制御連合講演会概要集,:1-5 2015(Nov. 14)
Author:森静奈; 矢向 高弘


実時間OS間の高精度時刻同期機構の実装と評価
第58回自動制御連合講演会概要集,:1-7 2015(Nov. 14)
Author:鞠谷達士; 矢向 高弘


スマートグリッドのための大規模ネットワークシミュレータの構築
情報処理学会第77回全国大会講演論文集,3:247-248 2015(Mar. 17)
Author:森静奈; 唐土慶太; 矢向 高弘


顕著性マップを用いて無線帯域変動に適応するライブビデオストリーミングシステム
情報処理学会第77回全国大会講演論文集,3:135-136 2015(Mar. 17)
Author:丸山大貴; 矢向 高弘


RT-Messenger を用いた時刻同期機構の実装と評価
情報処理学会第77回全国大会講演論文集,3:155-156 2015(Mar. 17)
Author:鞠谷達士; 上田和樹; 矢向 高弘


可視光通信のソフトウェア無線技術による適応制御に関する検討
情報処理学会第77回全国大会講演論文集,3:343-344 2015(Mar. 17)
Author:片山風人; 矢向 高弘


Selective Sending Block Determination Method Based on Quad-Tree Structure for Live Video Streaming Systems
IECON 2015 - 41ST ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY,:2367-2371 2015
Author:Ning Zhang; Takahiro Yakoh
Abstract:With the rapid development in internet and video coding technology, applications such as telesurgery and remote operations are becoming more and more popular. In such applications, any delay will significantly lower the performance and may sometimes lead to catastrophic results. As a result, lowdelay video streaming is demanded in such applications. Previous works have explored and established several live streaming systems based on fixed size block partitioning. Considering the effectiveness of identifying and extracting regions with similar image characteristics using variable sized block partitioning, this paper attempts to propose a live streaming system with variable sized block partitioning utilizing the quad-tree structure for lowdelay live video streaming under limited bandwidth.


OMNeT++を用いたEMSシミュレータの構築と性能評価
第57回自動制御連合講演会概要集,57:14-18 2014(Nov. 10)
Author:森静奈; 矢向 高弘
Abstract:電力系統の新しい制御手法として確率モデルに基づいた最適制御アルゴリズムの導入が検討されている.それらの提案は理論上,通信障害に対してロバストに設計されている.しかし万全を期すという観点から,想定される通信インフラを用いた大規模EMSをシミュレータ上に構築し,実際のネットワーク環境下での性能を評価しておくことが必要不可欠である.そこで本研究ではOMNeT++を用いて実際のEMSを想定した大規模なシミュレータを構築し,8000ノードまでの評価を行った.コンセントレータ1台に対し,800ノードを超えた場合に通信遅延が著しく大きくなることがわかった.


Feedback Controller with Low-Pass Filter based Delay Regulation for Networked Control System
IEEE Transactions on Industrial Electronics,61(7):3744-3752 2014(Jul. 01)
Author:矢代大祐; 矢向 高弘


低遅延ライブビデオストリーミングのための時間周波数推定に基づく送信ブロック画像選定手法
電気学会論文誌 C,134(12):1888-1896 2014
Author:阿部 太紀; 矢向 高弘
Abstract:To realize low delay live video streaming system over lossy network, each captured frame must be divided into block images, and these images must be encoded, packetized, and sent selectively. To improve the quality of reproduced frames at the receiver side, the selecting method of the block images must be sophisticated. This paper proposed an optimal selecting method of block images. The method consists of three phases based on the formulated two optimization problems. Firstly, a frequency analysis method is applied to the recent luminance value for each block area. Secondly, sendable block ratio is optimally distributed among block areas based on the result of frequency analysis to satisfy the available bandwidth condition. Finally, the optimal timings of sending are planned for each block area to minimize the error of reproduced image under the condition of assigned sendable block ratio. Some experiments were conducted to evaluate the proposed method using three frequently used reference video sequences. The results of comparison with the conventional method shows that the proposed method improved the mean squared error (MSE) of reproduced image up to 64%. Another results shows that the robustness of the proposed method against packet loss can be changed by modifying the parameter of the optimization problem.


近視領域作業のための可変輻輳機構を持つ立体視システムの設計と評価
電気学会論文誌 D,134(9):792-800 2014
Author:坂本 尚志; 矢向 高弘
Abstract:In general tele-operation, an operator watches a video captured by a remote camera to perceive the scene of the target operating space. However, typical monocular video diminishes the perceptivity and comfort of its operator because of the lack of a sense of depth. To provide a sense of depth, a binocular stereoscopic camera and 3D display are employed for a tele-operation system. In general, a stereoscopic camera must be adjusted for parallax, especially for near-field shooting. Therefore, a control strategy for the parallax of a binocular stereoscopic vision system is investigated. One of the serious issues for 3D displays is the vergence-accommodation conflict. Therefore, the proposed system controls its vergence angle to resolve the conflict for an object watched by an operator. To evaluate the perceptivity of the system, sensory evaluations were conducted using the proposed stereoscopic system that consists of a 3D display and pan-tiltvergence (PTV) controllable binocular stereoscopic camera. When the binocular parallax was controlled as proposed, the task completion time was shortened, and the correctness of a 2D-3D distinction test was improved. These results verified that the proposed system improves the perceptivity of the remote space, especially for near-field operation.


多重リングバッファ機構を用いた実時間通信とIP通信との両立手法
電気学会論文誌 C,134(8):1031-1038 2014
Author:上田 和樹; 鞠谷 達士; 矢向 高弘
Abstract:Recent Linux[7] kernel introduced an interrupt mitigation method called NAPI to reduce the overhead of interrupt handling procedures caused by frame arrival and transmission. However, NAPI caused serious delay and jitter in such procedures. On the other hand, many conventional real-time communication mechanisms were implemented independently to the existing network stack, and most of such mechanisms disabled the stack. Therefore, it is difficult to utilize both of real-time communication and IP communication in parallel. This paper proposed a parallel implementation method to realize both of real-time communication and IP communication simultaneously in a single computer unit. This method implement real-time network stack and IP network stack in parallel by using multiple queue functionality in a NIC (network interface card). Also, this method applied the interrupt mitigation method only to the IP stack. Therefore, this method achieved to reduce the overhead of the wide bandwidth of IP traffic, also to keep delay and jitter of real-time traffic enough small. Some experiments were conducted to measure the performance of the proposed method. The RTT (round trip time) delay of real-time communication was kept lower than 100 mu s even in high traffic load of 800 Mbitis with small jitter, while the RTT of IP communication varied between 100 mu s to 20 ms. This paper introduced the design, implementation, and evaluation of the proposed method.


Parallel Implementation of Real-Time Communication and IP Communication by using Multiple Ring Buffers
PROCEEDINGS OF 2014 10TH IEEE WORKSHOP ON FACTORY COMMUNICATION SYSTEMS (WFCS 2014),:1-8 2014
Author:Kazuki Ueda; Tatsushi Kikutani; Takahiro Yakoh
Abstract:Recent Linux[7] kernel introduced an interrupt mitigation method called NAPI to reduce the overhead of interrupt handling procedures caused by frame arrival and transmission. However, NAPI caused serious delay and jitter in such procedures. On the other hand, many conventional real-time communication mechanisms were implemented independently to the existing network stack, and most of such mechanisms disabled the stack. Therefore, it is difficult to utilize both of real-time communication and IP communication in parallel. This paper proposed a parallel implementation method to realize both of real-time communication and IP communication simultaneously in a single computer unit. This method implement real-time network stack and IP network stack in parallel by using multiple queue functionality in a NIC (network interface card). Also, this method applied the interrupt mitigation method only to the IP stack. Therefore, this method achieved to reduce the overhead of the wide bandwidth of IP traffic, also to keep delay and jitter of real-time traffic enough small. Some experiments were conducted to measure the performance of the proposed method. The RTT (round trip time) delay of real-time communication was kept lower than 100 mu s even in high traffic load of 800 Mbitis with small jitter, while the RTT of IP communication varied between 100 mu s to 20 ms. This paper introduced the design, implementation, and evaluation of the proposed method.


End-to-End Flow Control for Visual-Haptic Communication in the Presence of Bandwidth Change
ELECTRONICS AND COMMUNICATIONS IN JAPAN,96(11):26-34 2013(Nov.)
Author:Daisuke Yashiro; Dapeng Tian; Takahiro Yakoh
Abstract:This paper proposes an end-to-end flow controller for visual-haptic communication. A visual-haptic communication system transmits non-real-time packets, which contain large-size visual data, and real-time packets, which contain small-size haptic data. When the transmission rate of visual data exceeds the communication bandwidth, the visual-haptic communication system becomes unstable owing to buffer overflow. To solve this problem, an end-to-end flow controller is proposed. This controller determines the optimal transmission rate of visual data on the basis of the traffic conditions, which are estimated by the packets for haptic communication. Experimental results confirm that in the proposed method, a short packet-sending interval and a short delay are achieved under bandwidth change, and thus, high-precision visual-haptic communication is realized. (c) 2013 Wiley Periodicals, Inc. Electron Comm Jpn, 96(11): 26-34, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/ecj.11516


Feedback Controller with Low-Pass Filter based Delay Regulation for Networked Control System
IEEE Transactions on Industrial Electronics,61(7):3744-3752 2013(Jul. 01)
Author:矢代大祐; 矢向 高弘


帯域変動を伴う視触覚通信のための端末間フロー制御
電気学会論文誌D,132-D(6):600-606-7 2012(Jun. 01)
Author:矢代 大祐; 田 大鵬; 矢向 高弘


帯域幅に適応する多重記述符号化
情報処理学会論文誌,53(5):1489-1498-1498 2012(May 15)
Author:齋藤大地; 矢向 高弘
Abstract:多重記述符号化(MDC)は複数経路通信への応用が期待されるが,これまで回線の性能に適応する汎用的な符号化方式は提案されていない.本論文は,経路ごとに与えられる帯域条件に適応する記述子を生成可能な符号化法を提案する.確率密度分布が推定可能な応用には,エントロピー比を回線帯域の条件に適応させる符号化法式を提案している.また実時間応用など確率密度分布が推定不能な応用には,ビット幅を調整する符号化法式を提案している.提案する符号化法式を解析することにより,各々の特性を明らかにし,また実験結果から解析の有効性を検証している.Multiple description coding (MDC) is expected to apply multipath communication, though adaptive coding scheme to bandwidth constraints is not yet established. This paper proposes MDCs which adjust the size of multiple descriptions according to the bandwidth constraints. For applications that are possible to estimate possibility density function of transmitting data, entropy-configurable MDCs are designed. For applications in which it is hard to estimate possibility density function of transmitting data, bitwidth-configurable MDCs are designed. The characteristics of the proposed coding schemes are numerically analyzed. Also experimental results suggest the validity of the analysis.


Minimum Delay Switch for Synchronous TDMA Network
2012 INTERNATIONAL CONFERENCE ON COMPUTER SYSTEMS AND INDUSTRIAL INFORMATICS (ICCSII),:1-6 2012
Author:Hiroaki Nishijima; Takahiro Yakoh
Abstract:Minimum delay Ethernet switch was designed and implemented to construct Synchronous TDMA network. To minimize packet forwarding delay, a novel signal forwarding technique is introduced. The goal of this paper is realizing smaller delay than previous software based S-TDMA switch. The first point is discussion about some factors of delay and design to reduce them. In general, cut-through switch realizes shorter delay than store and forward switch. The proposed technique can realize shorter delay than cut-through switch in principle. To realize shorter delay, this paper proposed an implementation on FPGA boards. In addition, developing measurement equipment using FPGA and comparison between usual switch are also conducted. Experimental results of implemented hubs showed five times shorter delay and smaller jitter than usual software based implementation and other Ethernet switches. The maximum delay to transmit packet through each implemented switch in this paper was 400ns. This implement achieved low maximum delay of 1744ns and jitter of 40ns in 5-hops network. At the end of this paper, discussion about other delay factors and its affect to S-TDMA performance are also concluded.


Multiple Description Coding with Delta-Sigma Modulation
2012 10TH IEEE INTERNATIONAL CONFERENCE ON INDUSTRIAL INFORMATICS (INDIN),:863-868 2012
Author:Ryuta Shiomi; Daiki Abe; Takahiro Yakoh
Abstract:Multiple description coding (MDC) can be applied for multipath communication to reduce the negative affect of packet loss, and it is composed of three processes: encoding, quantizing, and decoding. Encoding and decoding are well researched in MDC, but there are few researches that focus on the quantization process. Therefore, this paper focuses on the quantization process of MDC. The aim of this paper is to improve the quality of the received data, and to reduce the bit width by employing static quantization (uniform quantization) with dynamic quantizer (Delta Sigma modulation). Performance evaluation was done using a block diagram input module XCos which is attached to the formula processing software Scilab. As a result of using the Delta Sigma modulation, the distortion improved by 95.2% when both of the descriptions were received, and 45.3% when only one of the description was received. Also, the experimental result showed that the quantization bit width can be reduced from 8 bit to 6 bit when the Delta Sigma modulation was used.


GPGPU Aided Method for Real-time Systems
2012 10TH IEEE INTERNATIONAL CONFERENCE ON INDUSTRIAL INFORMATICS (INDIN),:841-845 2012
Author:Yusuke Iwase; Daiki Abe; Takahiro Yakoh
Abstract:Guaranteeing real-time is required in the field of digital control. This is to start a task at a predetermined time, and complete the task before the predetermined deadline. However recently, it is getting difficult to guarantee such a completion. This is due to the fact that the amount of calculation within a period is increasing, and the period itself is being required to be shorter. As a method for parallel processing, GPGPU (General-Purpose computation on GPU) is recently attracting attention. However, tools to apply GPGPU to real-time system are not provided from the GPU vendor, and related research is not yet found. Therefore, this paper proposes and evaluates a method to operate GPGPU in real-time systems. From the experimental results, the proposed method dramatically reduced the jitter and the elapsed time comparing to the CPU itself, and also the conventional method. This shows that the proposed method improves the predictability of the completion time, and the GPU can be applied to real-time systems.


PD controller with LPF based jitter buffer for real-time communication
International Workshop on Advanced Motion Control, AMC,:1-6 2012
Author:Daisuke Yashiro; Takahiro Yakoh
Abstract:This paper proposes a jitter buffer for IP-based network which regulates packet-receiving interval. The proposed method utilizes a PD controller to adjust queue length of the jitter buffer to avoid overrun and underrun. In addition, the derivative value of packet-receiving interval is converged to zero by a low-pass filter. Proposed jitter buffer improves control performance of feedback control systems including time-varying delay elements. Validity of the proposed method is confirmed by experiments of position control through a network emulator. © 2012 IEEE.


触覚鉗子によるバイラテラル遠隔操作のための遅延補償器
日本コンピュータ外科学会誌,13(3):314-315 2011(Nov.)
Author:矢代大祐; 矢向 高弘


Optimal Dynamic Quantizer Based Acceleration Control with Narrow Bandwidth
IECON 2011: 37TH ANNUAL CONFERENCE ON IEEE INDUSTRIAL ELECTRONICS SOCIETY,:2612-2617 2011
Author:Daisuke Yashiro; Dapeng Tian; Takahiro Yakoh
Abstract:Data quantization is required to design motion control systems with narrow bandwidth. However, performance and stability is significantly deteriorated when control signals in feedback loop is quantized. Therefore, in this paper, optimal dynamic quantizer is utilized to compensate a quantized control signal of disturbance observer based acceleration control systems. Analytical results and experimental results of a position control through a network confirm the validity of the proposed approach. These results show that proposed approach reduces unignorable steady-state errors.


Auditory Decorator of Complex Sounds for Teleoperation Systems
2011 9TH IEEE INTERNATIONAL CONFERENCE ON INDUSTRIAL INFORMATICS (INDIN),:227-232 2011
Author:Hirohiko Kuramata; Takahiro Yakoh
Abstract:Communication delay in network is inevitable issue and it causes discomfort in manipulation of teleoperation systems. One of the solutions for this problem is decorator. Decorator is a technique to decrease the discomfort by modifying visual or auditory feedback based on the other information, which is transmitted with shorter delay, to its operator. In the former study, the artificial modification improves the usability of teleoperation. In this paper, we proposed an auditory decorator composed of complex sounds. Complex sounds have an ability to express multidimensional information. Therefore, with the complex sound, various information can be included in auditory information. We chose chord sounds and sign sounds as complex sounds and implemented the auditory decorator. From result of the user study to evaluate the proposed decorator, the proposed decorator is more effective to improve the usability of teleoperation system than the conventional one.


Three Ratio Configuration Methods for Multiple Description Correlating Transform Coding
2011 IEEE INTERNATIONAL SYMPOSIUM ON INDUSTRIAL ELECTRONICS (ISIE),:826-831 2011
Author:Daichi Saitoh; Takahiro Yakoh
Abstract:Multiple description coding (MDC) is one of source coding techniques to encode realtime application source into multiple bitstreams. MDC supports multiple quality levels of decoding when transmitted over lossy channels such as packet networks. An MDC source encoder provides different representations of the source such that; when all descriptions are available at the receiver, an high-quality reconstruction of the source is possible, while if only a small number of descriptions is available, a reconstruction is still possible even though a lower quality, but acceptable is obtained. Therefore, this coding technique is expected to apply applications which prefer accepting error of data to retransmitting the lost or erroneous data over multipath noisy network. Multiple Description Correlating Transforms coding (MDCTC) is a method to realize MDC with a matrix. Based on this method, this paper proposes the three ratio configuration method for Multiple Description Correlating Transforms coding (RMDCTC), which can control the volume ratio of descriptions to source data. Therefore, RMDCTC can adjust the data size ratio among descriptions to fit the ratio of channel bandwidths and is suitable to apply error allowable communicating applications over asymmetric multipath noisy network. In addition, each three ratio configuration method has different feature. Therefore, it is possible to select suitable method as the situation demands. As a result, the proposed methods are more practical method than traditional MDCTC.


Ratio configurable Multiple Description Correlating Transforms Coding
2011 IEEE INTERNATIONAL CONFERENCE ON INDUSTRIAL TECHNOLOGY (ICIT),:352-357 2011
Author:Daichi Saitoh; Takahiro Yakoh
Abstract:Multiple description coding (MDC) is one of source coding techniques which generate several descriptions from a single data. A decoder of MDC reconstructs the data from these descriptions. Even if some descriptions are lost, the decoder can reconstruct a similar data from the other descriptions. Therefore, this coding technique is expected to apply applications which prefer accepting error of data to retransmitting the lost or erroneous data over multipath noisy network. Multiple description correlating transforms coding (MDCTC) is a method to realize MDC with a matrix. Based on this method, this paper proposes the method, ratio configurable multiple description correlating transforms coding (RMDCTC), which can adjust the data size ratio among descriptions to fit the ratio of channel bandwidths. The proposed method is suitable to apply error allowable communicating applications over asymmetric multipath noisy network. Mathematical analysis and experimental results verify the effectiveness of the proposed method.


触覚を有する8自由度手術用両腕ロボットの開発
日本コンピュータ外科学会誌,12(3):208-209 2010(Nov.)
Author:三留郁弥; 矢向 高弘


Feasibility Study of GPGPU Acceleration for PC-based Control
8th France-Japan and 6th Europe-Asia Congress on Mechatronics,:560-563 2010(Nov.)
Author:Keita Koyama; YAKOH TAKAHIRO
Abstract:GPUを用いた制御計算高速化の可能性についてGPGPUの優位性および実時間OSからの利用方法の観点から検討した上で、実時間OSからの利用方法の枠組みを提案し、実装・評価を通じて検証を行った。


ネットワークを介したサーボ制御のためのPI制御器を用いた端末間フロー制御
電気学会論文誌,130-D(3):268-276-276 2010(Mar.)
Author:矢代大介; 久保亮吾; 矢向 高弘; 大西公平
Abstract:This paper presents a novel flow control method using a PI controller for servo control over networks. The UDP is known to be effective for motion control systems over networks such as bilateral teleoperation. However, UDP does not have a mechanism for congestion avoidance. The congestion, which causes large communication delay, jitter, and packet loss, deteriorates the performance and stability of control systems over networks. To avoid this congestion, a novel flow control method, which adjusts a packet-sending period in real time, is proposed. The validity of the proposed method is shown by simulation and experimental results.


Development of 16-DOF Telesurgical Forceps Master/Slave Robot with Haptics
IECON 2010 - 36TH ANNUAL CONFERENCE ON IEEE INDUSTRIAL ELECTRONICS SOCIETY,:2081-2086 2010
Author:Wataru Motooka; Takahiro Nozaki; Takahiro Mizoguchi; Keisuke Sugawara; Fumiya Mitome; Keishi Okuda; Midori Miyagaki; Daisuke Yashiro; Takahiro Yakoh; Kouhei Ohnishi; Yasuhide Morikawa; Naoki Shimojima
Abstract:Minimally invasive surgery (MIS) has attracted attention recently. MIS such as endoscopic surgery considers a patient's quality of life. In endoscopic surgeries, bilateral control systems are strongly required to apply. It is necessary to develop the multi Degrees Of Freedom (DOF) robot to achieve various operation procedures including endoscopic surgery. In this paper, 16-DOF haptic telesurgery master/slave robot is developed. This master/slave robot has two arms, and each arm has 8-DOF. The bilateral control using 4ch controller is implemented in the master/slave robot. Experiments of peeling motion and suturing motion are performed by a surgeon to evaluate the development robot.


Data transmission using priority queue for multi-DOF haptic communication
International Workshop on Advanced Motion Control, AMC,:70-75 2010
Author:Daisuke Yashiro; Takahiro Yakoh; Kouhei Ohnishi
Abstract:This paper proposes a novel data transmission method for a haptic communication through LAN. In a practical sense, the terminals, that implement the bilateral control, are connected through a number of concentrators. These concentrators have communication-bandwidth limitation. This limitation make it impossible to achieve both of short packet-sending period tp and low delay T, because short tp often causes a network congestion. As a result, the enough large tp, which never causes the network congestion, is often selected taking the worst traffic condition into account. However, this approach deteriorates the transparency of the haptic communication. To solve this problem, this paper innovates a priority queue (PQ) at the switch to reduce the large delay in case of the network congestion. As a result, highly transparent bilateral control through LAN is achieved. The validity of the proposed method is confirmed by the experiment. © 2010 IEEE.


A detection method of active queue management in communication paths
Proceedings of the IEEE International Conference on Industrial Technology,:1009-1013 2010
Author:Junji Iwatani; Takahiro Yakoh
Abstract:In this paper, we discuss how to discriminate the queue type in the network for end-to-end congestion control. FAST TCP is one of end-to-end congestion avoidance techniques and designed to accept FIFO and drop tail queue. However, existing AQM routers in the recent Internet may interrupt that such end-to-end congestion avoidance protocols perform well. At first, we examine the behavior of FAST TCP over RED router by simulation and show ploblems. Then, we discuss how to discriminate the queue type in FAST TCP communications. ©2010 IEEE.


Hybrid Multipath Routing for Packet Distribution using Ant Colony Optimization
6th International Conference on Information Technology and Applications,:6 pages 2009(Nov.)
Author:Distad Chirananthava; 矢向 高弘
Abstract:インターネットにおいて,利用可能な複数経路を動的にかつ自律分散的に探索するアルゴリズムを提案し,PlanetLabを用いた地球規模の実験評価を通じて有効性を示している。


End-to-End Flow Control using PI controller for Force Control System over TCP/IP Network
2009 7TH IEEE INTERNATIONAL CONFERENCE ON INDUSTRIAL INFORMATICS, VOLS 1 AND 2,:194-199 2009
Author:Daisuke Yashiro; Takahiro Yakoh; Kouhei Ohnishi
Abstract:This paper presents a novel flow control method using PI controller for motion control system over network. UDP/IP protocol is known to be effective for motion control systems over network such as bilateral control system. However, UDP does not have a mechanism of congestion avoidance. The congestion, which causes large communication delay, jitter and packet loss, significantly deteriorates performance and stability of motion control systems. To avoid this congestion, a novel congestion control method, which adjusts a packet-sending period in real time, is proposed. The validity of the proposed method is shown by simulation and experimental results.


Low delay live video streaming system for interactive use
IEEE International Conference on Industrial Informatics (INDIN),:1481-1486 2008
Author:Kenta Endoh; Kurima Yoshida; T. Yakoh
Abstract:With the rapid growth of the Internet, users are increasingly seeking real-time multimedia application services. To meet this requirement, many streaming methods are developed. However, most of streaming systems are used for ornamental use such as video on demand(VOD). Users for such application do not require interaction, so reducing jitter is the most important issues. Therefore, users don't demand low delay systems. On the other hand, the systems for the interactive use such as remote control, tele-surgery and so on, demand the extremely low delay and low jitter. This article propose the new live video streaming system featured by the low delay and low jitter. This paper expresses the methods of encoding and transmitting videos and describes the results of the simulations that indicate the availability of the system. ©2008 IEEE.


Implementation and evaluation of decorators for delayed live streaming video on remote control system
IEEE International Conference on Industrial Informatics (INDIN),:1220-1225 2008
Author:Shinichi Hamasaki; Takahiro Yakoh
Abstract:A remote control system is one of the applications of communication. An user at a local side requires feedback information from a remote side to operate. In general, visual information and haptic information are used. However, it is impossible to synchronize local side and remote side perfectly because of communication delay and processing time. When the delay becomes long, the operability of remote control system becomes worse. To overcome this difficulty, this article proposed to introduce visual decorators, which are mainly researched in the field of virtual reality, in remote control system. The proposed decorators superimposed real-time remote side information on delayed remote video playout. A position decorator indicated the position of remote robot, and a force decorator indicated the force of the robot. Experimental results showed two decorators improve the operability of the remote control system over network with delay. This results confirmed the effectiveness of proposed decorators for remote control system with delayed video playout. ©2008 IEEE.


Fault Tolerant Multipath Routing with Overlap-aware Path Selection and Dynamic Packet Distribution on Overlay Network for Real-Time Streaming Applications
WFCS 2008: IEEE INTERNATIONAL WORKSHOP ON FACTORY COMMUNICATION SYSTEMS, PROCEEDINGS,:287-+ 2008
Author:Tatsuo Ishida; Takahiro Yakoh
Abstract:In this paper we propose overlap-aware path selection and dynamic packet distribution due to failure detection in multipath routing overlay network. Real-time communications that utilize UDP do not ensure reliability for realizing transmission. Therefore congestion or failure in a network deteriorates the quality of service significantly. The proposed method seeks an alternate path that hardly overlaps an IP path so as to improve its reliability. The proposed method also detects congestion or failure by differential of packet loss rate and apportion packets to the IP path and the alternate path dynamically. Evaluation on PlanetLab shows the proposed method avoids congestion Consequently the influence of congestion and failure lessens and the proposed multipath routing improves the reliability which can be used for real-time communications.


Cooperative Route Searching System Considering Dynamics of Traffic Flow
6th IFAC Symposium on Intelligent Autonomous Vehicles,:6 pages 2007(Sep.)
Author:堤計太; 矢向 高弘
Abstract:ネットワークルーティングの技術を車両経路制御へ応用することにより、道路交通網全体としてのスループットを向上することを提案し、シミュレーションにより効果を示している。


Fairness and Utilization in Multipath Network Flow Optimization
IEEE International Conference on Industrial Informatics,:1096-1101 2006(Aug.)
Author:石田達夫; 上田健吾; 矢向 高弘
Abstract:ネットワークフロー問題を公平性と利用効率を両立させるために多目的最適化問題として記述し、これを解くことにより達成できることを示した。


Performance Evaluation of Synchronous TDMA Switching Hub in Multi-hop Environment
IEEE International Workshop on Factory Communication Systems,:321-328 2006(Jun.)
Author:上田健吾; 矢向 高弘
Abstract:IXP-1200を用いて同期型TDMAスイッチングハブを実装した。マルチホップ環境下での通信遅延を実測することで、本実装の実時間性が優れていることを示した。


ネットワークを介したバイラテラル遠隔操作
電気学会論文誌,126-D(2):161-167-167 2006(Feb.)
Author:名取賢二; 辻俊明; 矢向 高弘; 大西公平
Abstract:オブザーバ理論をむだ時間補償に応用することを考案し、通信を介したバイラテラルシステムに適用し、信濃町-矢上間のキャンパスネットワーク上での実験により有効性を示している。


A Controller Design Method for Mutually Interacted Decentralized Systems
計測自動制御学会論文集,41(7):547-554-554 2005(Jul.)
Author:Yutaka Uchimura; YAKOH TAKAHIRO; Kohei Ohnishi
Abstract:個別に設計された制御器が相互作用しあう分散システム全体の振る舞いや安定性について定式化・解析し、その上で複数制御器の構成法および制御器設計の手続きを含む総合的な分散システムの制御系設計手法を提案している。


Bilateral robot system on the real-time network structure
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS,51(5):940-946 2004(Oct.)
Author:Y Uchimura; T Yakoh
Abstract:This paper presents a bilateral robot system, which is driven by the static friction-free drive system and implemented on the real-time network structure. The goal is to realize a force reflecting bilateral teleoperation with haptic impression transmission over computer networks. The paper considers two subjects relating to the bilateral robot. The first is static friction, which degrades the performance of manipulation and results in a poor haptic impression. A new transmission mechanism named twin drive system developed by the authors resolves this problem. The transmission mechanism, which resembles the differential gear of automobiles, is essentially free of static friction. This static-friction-free motion greatly contributes to the broad range of motion control applications. The second subject is the time delay of the network, which may cause serious problems such as instability of the feedback system. To avoid such delay, the authors developed a new real-time network protocol stack (RTNP). The detailed mechanism of the twin drive system and architecture of the RTNP are presented, and the control scheme and experimental results are also shown.


A Controller Design Method on Decentralized Systems
IECON 2004: 30TH ANNUAL CONFERENCE OF IEEE INDUSTRIAL ELECTRONICS SOCIETY, VOL 3,:2961-2966 2004
Author:Yutaka Uchimura; Takahiro Yakoh; Kouhei Ohnishi
Abstract:In this paper, we propose a new controller design method of for decentralized system. The method includes an arrangement scheme of multi-controllers and a controller design procedure via the LMI method. The arrangement scheme is based on analysis of a transitional probability matrix, which is induced from a connection matrix. In the scheme, we characterize the stable equilibrium value of probability matrix as the dense of the connection and determines the order of the subsystem. Multi-controllers are arranged according to the priory order and constitute a decentralized control system. The controller design utilizes the function of LMI based methods, which enables one to put constraints on the form of the feedback controller. By applying a change of variables method and setting up the structure of variable to be the same as the controller structure, the desired controller is obtained. We show a design procedure of a stabilizing controller. The validity of proposed methods is examined on a numerical model.


Development of time division switching hub for synchronous TDMA
WFCS 2004: IEEE INTERNATIONAL WORKSHOP ON FACTORY COMMUNICATION SYSTEMS, PROCEEDINGS,:45-50 2004
Author:K Ueda; T Yakoh
Abstract:In this article. the prototyping of a synchronous hybrid switching hub is discussed. It uses the network processor IXP 1200 in multi-hop networks. In general, transmission times caused by a switching hub / router vary according to its load and the traffic of networks. it is because delay distributes whenever packets pass through a router even if real-time communication net-works are used for all subnets. To stabilize the transmission time, this article proposes a real-time switching hub for the protocols so as to synchronize all of communication and forwarding processes for a periodical communication for global networks.


Development of gel-structured electro-rheological fluids and their application to mechanical damper elements
8TH IEEE INTERNATIONAL WORKSHOP ON ADVANCED MOTION CONTROL, PROCEEDINGS,:541-545 2004
Author:Y Kakinuma; T Yakoh; T Aoyama; H Anzai
Abstract:Electrorheological fluids E are functional fluids whose viscoelastic property varies according to the intensity of the applied electric field. The disadvantages of E are the sedimentation of E particles and the requirement of seal mechanism. n order to solve these problems, gel structured elecrorheological fluids E are developed in this study. The basic characteristics of E film is experimentally analy ed. ased on the results of basic analysis, the E was applied to the mechanical damper elements.


End-to-end delay evaluation on multipath routing IP network
8TH IEEE INTERNATIONAL WORKSHOP ON ADVANCED MOTION CONTROL, PROCEEDINGS,:481-486 2004
Author:S Hakataya; T Yakoh
Abstract:Real-time communication infrastructure is required for distant motion control. This paper proposes a multipath policy routing based on class-based queueing. Isolating queues and links for an UDP's real-time flow from other non real-time flows, it is expected to reduce the delays and jitters of a real-time flow. Some simulation results show the efficiency of our proposal. It turns out that our proposed multipath routing achieves minimum end-to-end delay theoretically, and eliminates the jitter of real-time flow whether a bottleneck link exists or not.


A real-time network based bilateral robot control with prioritized transfer of state variables
8TH IEEE INTERNATIONAL WORKSHOP ON ADVANCED MOTION CONTROL, PROCEEDINGS,:475-480 2004
Author:Y Uchimura; T Yakoh; K Ohnishi
Abstract:This paper proposes a prioritization scheme of the control state variables transmitted via a computer network, considering time delay. The robustness of each state variable against time delay is evaluated, and then the priority order is assigned. The priority based data transfer is implemented on a real-time network system by a device named Responsive Processor. The network system is applied to a bilateral robot system, which is driven by a controller based on impedance matching theory. The control algorithm employs an adaptive hybrid control method, which adjusts the hybrid combination ratio of position control and force control depending on the variation of the remote environment. Experiments were conducted to evaluate the priority assignment. Various combinations of the time delay and state variables were set up. The results conducted to the different stiffness objects, verified the effectiveness of priority assignment and supported the analytical results.


構造ヘルスモニタリング用ワイヤレスセンサに関する研究
日本地震工学論文集,3(4):1-13-13 2003(Nov.)
Author:長井望; 三田彰; 矢向 高弘; 佐藤忠信
Abstract:構造ヘルスモニタリング用にワイヤレスネットワーク技術を応用したセンサネットワークを提案し、理論解析、プロトタイプ製作、評価試験を行った。


分散リアルタイム制御技術の研究
情報処理学会誌,44(1):27-33 2003(Jan.)
Author:H矢向 高弘; HR#H内村裕; HR#H森澤光晴; HR


Real-time network system by Responsive Processor and its application to bilateral robot control
IECON'03: THE 29TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY, VOLS 1 - 3, PROCEEDINGS,40(2):1209-1214 2003
Author:Y Uchimura; T Yakoh; N Yamasaki; K Ohnishi
Abstract:This paper presents a new network device, which is named Responsive Processor, plus its message handler, which is a basic protocol for the device. These are designed for a hard real-time control application such as a robot control. By using the Responsive Processor and message handler, we developed a bilateral robot system that transfers haptic impression over a network. First, we discuss the network system requirements from the view of real-time control. Then, we introduce the main features and functions of the Responsive Processor. Implementation of the message handler, which is designed to maintain real-time performance, is described in detail. Benchmarks for using the message handler with the Responsive processor are also shown. The results of experiments conducted on a bilateral robot system verified real-time performance of the entire system.


Synchronous Time Division Internet for Time-Critical Communication Services
Proc. of EUROMICRO International Workshop on Real-Time LANs in the Internet Age,:111-115 2002(Jun.)
Author:矢向高弘
Abstract:実時間通信を可能にするためのインターネットの拡張方法として同期型時分割方式を提案した。また実装方法についても提案している。


Dynamic model of decentralized systems with informational connection
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS,49(3):707-715 2002(Jun.)
Author:Y Fujimoto; T Yakoh; K Ohnishi
Abstract:This paper presents a design method of decentralized systems with informational connection. The informational connection in this paper denotes an event link which establishes a signal links among physical controlled plants via a communication network. A dynamic transition of an informational connection among decentralized systems is considered and the mathematical structures are discussed using a concept of eigenvalues and eigen-connections over the Galois field GF(2). The global system has variable-structure characteristics due to the transition of informational connection. Examples of decentralized variable-structure systems are shown. In industry, there are many engineering systems that have a dynamic transition of an informational connection. The mathematical model would be useful for analysis and synthesis of various informationally connected systems.


Dynamic model of decentralized systems with informational connection
IEEE transactions on industrial electronics,49(3):707-715 2002(Jun.)
Author:Fujimoto Yasutaka; Yakoh Takahiro; Ohnishi Kouhei
Abstract:This paper presents a design method of decentralized systems with informational connection. The informational connection in this paper denotes a event link which establish a signal links among physical controlled plants via communication network. A dynamic transition of informational connection among decentralized systems is considered and the mathematical structures are discussed using a concept of eigenvalues and eigen-connections over the Galois field GF(2). The global system has variable structure characteristics due to the transition of informational connection. Examples of decentralized variable structure systems are shown. In an industry field, there are many engineering systems that have dynamic transition of informational connection. The mathematical model would be useful for analysis and synthesis of various informationally connected systems.


Configuration and readhesion control for a mobile robot with external sensors
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS,49(1):241-247 2002(Feb.)
Author:Y Umeda; T Yakoh
Abstract:Since a wheeled mobile robot is subject to non-holonomic constraints, the position and the configuration of the robot cannot be derived directly from only the rotation angle of its wheels. In other words, the position and the configuration of a mobile robot cannot be calculated correctly if its wheels skid. For the purpose of the position estimation of a mobile robot, some external sensors are used, in general. This paper uses position information from a position-sensitive detector camera that is a high-speed visual sensor to correct the errors that are due to skid and so on. Also, we estimate a skid of wheels by using its visual information. In this paper, we propose a control system that enables control of both the configuration of the robot and the skid of wheels simultaneously by including these estimated values in the control loop of a mobile manipulator.


Synchronized TDMA in multi hop network to stabilize transmission time
IECON-2002: PROCEEDINGS OF THE 2002 28TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY, VOLS 1-4,:2903-2908 2002
Author:T Yakoh
Abstract:In this article, transmission time in multi hop networks is discussed. In general, transmission times caused by a router vary according to the router's load and traffic of networks. So when two nodes communicate with each other via some routers, real-time property never be ensured even if these nodes are a part of subnet organized by conventional factory communication systems. To stabilize the transmission time, this article propose to revise factory communication protocols so as to synchronize the assignment of time-slots for a periodical communication for each side segments of routers. Very simple example of synchronized time-slot assignment method is also shown.


Smooth tactile display in mouse using electro-rheological gel
ISIE 2002: PROCEEDINGS OF THE 2002 IEEE INTERNATIONAL SYMPOSIUM ON INDUSTRIAL ELECTRONICS, VOLS 1-4,:424-429 2002
Author:K Matsuura; T Yakoh; T Aoyama; H Anzai; K Sakurai; K Isobe
Abstract:In recent years, mice have been used widely as one of the important pointing devices of a computer. The mouse which has high performance and multiple functions is required in order to improve the usability of a computer. Some researches which add a tactile display function to a mouse have been done, and mice with the tactile display using a vibrator have been put on the market. However. acoustic noise generated by the vibrator make its user uncomfortable. Then., this article proposed and developed a new tactile display mouse using passive and fail-safe device called ERG (Electro-rheological Gel). First. the characteristics of ERG were measured through some experiments. From the results, it is found that the stiffness of ERG is an electrically controllable characteristic when ERG and electrode is sliding. Then the device was incorporated into the click button of a mouse and evaluated through some identification tests by some human to identify the button's stiffness. In shortly, identification rate was over 90%. Consequently, the developed tactile display can successfully express multi-level of tactile senses. Finally some application of the tactile display also proposed.


Network resource allocation method for communicating control systems
7TH INTERNATIONAL WORKSHOP ON ADVANCED MOTION CONTROL, PROCEEDINGS,:80-85 2002
Author:N Nagai; T Yakoh
Abstract:In order to realize distributed control systems, it is required to tie tip plural distributed subsystems through a network, and the fusion of control engineering and realtime communication technology is also required. In this article, a new network resource allocation method is proposed. This is based on a traffic control queuing mechanism called ALTQ. To fill the delay time constraints for each flow, an online measurement mechanism of each packet transmission time in a router is introduced into a conventional ALTQ to limit the number of flows. This article shows the design and the implementation of the measurement mechanism. Also some experimental results shows the efficiency of the proposed method.


Bilateral robot system on the real time network structure
7TH INTERNATIONAL WORKSHOP ON ADVANCED MOTION CONTROL, PROCEEDINGS,:63-68 2002
Author:Y Uchimura; K Ohnishi; T Yakoh
Abstract:This paper presents a bilateral robot system, which is driven by the static friction free drive system and implemented on the real time network, structure. The goal is to realize a force feedback teleoperation with haptic impression transmission over computer networks. The paper considers two subjects relating to the bilateral robot. The first is static friction, which degrades the performance of manipulation and results in a poor haptic impression. A new transmission mechanism named a "twin drive system" developed by the authors resolves this problem. The transmission mechanism, which resembles the differential gear of automobiles, is essentially free of static friction, because all the components are always spinning. This static friction free motion greatly contributes to the broad range of motion control applications. The second subject is the time delay of the network, which may cause serious problems such as instability of the feedback system. To avoid such delay, the authors developed a new real-time network structure and protocol. The detailed mechanism of the twin drive system and architecture of the real-time protocol are presented, and the control scheme and experimental results are shown.


ツインドライブシステムを用いたセンサレスバイラテラルロボットマニピュレータ
精密工学会誌,Vol.67(No.11):1834-1838-1838 2001(Nov.)
Author:林田宣宏; 矢向高弘; 村上俊之; 大西公平
Abstract:モータの摩擦を低減するツインドライブシステムを提案し、センサレスバイラテラルロボットに応用した。


A sensorless bilateral robot manipulator based on twin drive system
Seimitsu Kogaku Kaishi/Journal of the Japan Society for Precision Engineering,67(11):1834-1838 2001(Nov.)
Author:Nobuhiro Hayashida; Takahiro Yakoh; Toshiyuki Murakami; Kouhei Ohnishi
Abstract:A bilateral robot is one of the remote control robots. By implementing the force feed back, it is possible for the operator to have the sense of the touch. But the force sensor is affected by unknown disturbance such as its temperature variation and so on. For that reason, it is not expected to use the force sensor at the extreme situation. In the sensorless approach, the reaction torque observer is used. But the reaction observer is easy to be influenced of the friction. This makes it difficult to estimate the external force. To address the above issue, this article proposes a twin drive system. This system is composed of two motors and one differential mechanism. It is required to control two motors for two degrees of freedom. To consider the above issue, two virtual motors are proposed. One is deal with the output control and the other is for friction compensation. The twin drive system brings a sophisticated ability to the system, which is a reduction ability of the friction. By using this system, it is possible to realize the remote control robot, where the operator can feel the obstacle which the slave robot touches. This system may help the remote control work more skillfully. The validity of the proposed method is confirmed by the experimental results.


電気粘性流体のクラッチ機構への応用に関する研究
日本機械学会論文誌(C編),Vol.67(No.657):409-414 2001(May)
Author:三ツ木勇人; 矢向高弘; 青山藤詞郎; 桜井宏治
Abstract:電気粘性流体を用いて電気的にトルク伝達率を変化させることが可能なクラッチ機構を試作した。


複数台ハンドアイシステムにおける複数対象物追従制御
精密工学会誌,Vol.67(No.3):473-477 2001(Mar.)
Author:矢向高弘; 青木貴史; 大西公平
Abstract:複数台のハンドアイで複数対象物を追う際、対象物が交差してもハンドアイ同士が衝突することなく追従できる制御方式を提案した。


移動マニピュレータにおける台車とアームの協調作業
電気学会論文誌,121-D(3):377-382-382 2001(Mar.)
Author:矢向高弘; 中村大介
Abstract:マニピュレータの乗った台車全体を冗長マニピュレータとして捉え、直行2軸に位置と力の非干渉なハイブリッド制御系を構成した。


仮想力伝播に基づく協調マニピュレータの分解制御
精密工学会誌,Vol.67(No.2):241-245-245 2001(Feb.)
Author:矢向高弘; 伊藤正尚; 大西公平
Abstract:多関節マニピュレータにおいて、エンドエフェクタからベースへ向かって仮想力を伝播させるという、ヤコビ行列を用いない新しい逆運動学解法を提案し、協調マニピュレータの制御に応用している。


時間制約の厳しいマルチメディアのためのリアルタイム通信機構
情報処理学会論文誌,Vol.42(No.2):189-196 2001(Feb.)
Author:佐藤秀雄; 矢向高弘
Abstract:物体の質感を伝える新しいメディアの概念を提案し、試作を行っている。特に、これを遠隔地で実現するためのリアルタイム通信機構の設計と開発、性能評価について述べている。


Fundamental Study on Electro-Rheological Fluids and Their Applications to Force Display Devices
Proc. of International Conference on Mechanical Engineering 2000(Nov.)
Author:鈴木順也; 矢向高弘; 青山藤詞郎; 桜井宏治
Abstract:電気粘性流体をクラッチの媒体として利用した際の基本性能を測定した。また、PID制御を行うことにより、力覚提示装置の試作を行っている。


Motion Control of Unconstrained Object by Multiple Mobile Robots
IEEE. International Conference on AdvancedMotion Control(AMC2000),:120-125 2000(Mar.)
Author:T.Yajima; T.Yakoh; T.Murakami; Kouhei Ohnishi
Abstract:本論文では,複数台移動ロボットによる対象物押し作業に伴う位置と力のハイブリッド制御手法を提案している.特に,対象物の安定な運搬走行を実現するための力分配法について示している.


自律分散制御におけるシステムのダイナミカル結合の一表現法
電気学会論文誌,120-D(1):80-87-87 2000(Jan.)
Author:石建信; 藤本康孝; 矢向 高弘; 大西公平
Abstract:コンピュータネットワークに代表される情報結合システムを数学的に表現するための定式化を行っている。


情報結合システムの動的モデル
電気学会論文誌,120-D(1):19-28-28 2000(Jan.)
Author:藤本康孝; 石建信; 矢向 高弘; 大西公平
Abstract:コンピュータネットワークに代表される結合が時間変化を行う情報結合システムを数学的に取り扱うための手法を提案している。


Analysis and synthesis of decentralized systems with informational connection
IECON 2000: 26TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY, VOLS 1-4,:2602-2607 2000
Author:Y Fujimoto; T Yakoh; K Ohnishi
Abstract:This paper presents a design method of decentralized systems with informational connection. The informational connection in this paper denotes a event link which establish a signal links among physical controlled plants via communication network. A dynamic transitions of informational connection among decentralized systems is considered and the mathematical structures are discussed using a concept of eigenvalues and eigen-connections over the Galois field GF(2). The global system has variable structure characteristics due to the transition of informational connection. One example of a decentralized realization of sliding mode control is shown. In an industry field, there are many engineering systems which have dynamic transition of informational connection. The mathematical model proposed in this paper will be useful for analysis and synthesis of various informationally connected systems.


A real-time communication mechanism for RTLinux
IECON 2000: 26TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY, VOLS 1-4,:2437-2442 2000
Author:H Sato; T Yakoh
Abstract:This article proposes a new real-time communication mechanism called RT-Messenger. This mechanism is designed to handle communication messages with interrupt-level priority. Although RT-Messenger is independent to communication devices, we implemented this mechanism to support Ethernet as additional functions of RTLinux, a real-time extended Linux. Some performance evaluations show that this mechanism is enough fast to communicate and to synchronize between two real-time programs which run on different computers. Also an experimental result shows that two robot systems are successfully controlled bilaterally.


Application of electro-rheological fluids to flexible mount and damper devices
IECON 2000: 26TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY, VOLS 1-4,:1815-1820 2000
Author:T Yakoh; T Aoyama
Abstract:This article introduces two applications of Electro-Rheological Fluid (ERF), an ERF rubber flexible mounting element and an ERF Damper, in order to suppress the vibration of machine elements. Both of them are manufactured and the results of their basic performance measurements confirm that the compliance and the damping of them can be changed according to the intensity of applied electric field. Also three ERF mounts applied to the supporting elements of a table make the resonance frequency of the table changeable. Furthermore the ERF damper applied into a tool shank increases the accuracy of cutting process.


A sensorless force control in twin drive system
IECON 2000: 26TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY, VOLS 1-4,:2231-2236 2000
Author:N Hayashida; T Yakoh; T Murakami; K Ohnishi
Abstract:This article describes the method of a sensorless force control in twin drive system. The twin drive system is composed of two motors connected by a differential mechanism. Its generated output is the difference of torque between two motors. Since its two motors can continue to drive even when the system makes a stationary motion, the effective static friction of the system is drastically reduced. The disturbance torque is so small, this system is able to estimate the eternal disturbance torque more than usual motor. By using this system, it is possible to construct, the force sensorless controller more exactly.


A comparison study between parallel and serial linked structures in biped robot system
IECON 2000: 26TH ANNUAL CONFERENCE OF THE IEEE INDUSTRIAL ELECTRONICS SOCIETY, VOLS 1-4,:2614-2619 2000
Author:M Morisawa; T Yakoh; T Murakami; K Ohnishi
Abstract:This article describes the features of two contrastive mechanisms in biped robot system. One of the compared models is the serial mechanism in which each link is connected in series. Each joint is driven by its own actuator independently. Another model is the parallel mechanism and there is a single close linked chain. One of the important merits of using parallel mechanism to the biped robot is that all actuator can be placed on the upper leg, thus the inertia of the leg can be smaller, even if its kinematics and dynamics becomes more complicated. In the biped robot with parallel mechanism, all joint angle is set as a variable as well as serial mechanism and the geometric constraint function can be defined by the kinematic relation of every close I linked chain. From the second order differential of this function, the angular acceleration of passive joint is represented by the angular acceleration of the active joint. Thus the dynamic equation is derived. In this paper, theoretical analysis of the biped robot motion with parallel and serial mechanism are shown. Various numerical results are useful to a mechanical design.


Fine real-time processing in distributed systems
2000 IEEE INTERNATIONAL WORKSHOP ON FACTORY COMMUNICATION SYSTEMS, PROCEEDINGS,:135-142 2000
Author:T Yakoh; H Sato; T Aoyama
Abstract:In this article, a simple communication mechanism for real-rime operating systems is proposed to support communicating real-time processes in distributed systems. To extract the primitive requirements for a communication mechanism, communicating real-time processes are classified and discussed. Then a communication mechanism is designed to meet these requirements. The proposed mech anism handles communication messages with interrupt-level priority cooperatively with the real-time scheduler which are working in the target real-time operating system. Although the proposed mechanism is independent to the target operating systems and communicating devices, this article shows the implementation of this mechanism as an additional subsystem for RT-Linux, a real-time extended Linux, to support Ethernet. Some performance evaluations show that this implementation is enough fast to communicate and to synchronize between two real-rime processes which is running on different computers. Also an experimental result shows that two robot systems are successfully controlled cooperatively connected with Ethernet. These results shows the proposed mechanism is quite efficient to build communicating real-lime processes in distributed systems.


A motion control of unconstrained object in mobile robot system
6TH INTERNATIONAL WORKSHOP ON ADVANCED MOTION CONTROL, PROCEEDINGS,:120-125 2000
Author:T Yajima; A Nagami; T Yakoh; T Murakami; K Ohnishi
Abstract:This paper describes a strategy far a pushing operation by wheeled robot. In the conventional approach, the kinematics of the pushing object is mainly focused without considering the dynamical effects such as friction. In this case, it is difficult to cope with environmental variations since the contact point of pushing motion is fixed on the object's surface and the motion of the end effector is limited by friction earn. To address the above issue, the proposed approach makes it possible to achieve not only the control of driving force but also the position control of contact point by using hybrid controller based on disturbance observes: Here the disturbances are compensated by workspace observer so that an acceleration control of the object is realized in workspace. Then the configuration control of the whole system is also easily carried out. Several numerical and experimental results are also shown to confirm the feasibility of the proposed method.


A friction compensation in twin drive system
6TH INTERNATIONAL WORKSHOP ON ADVANCED MOTION CONTROL, PROCEEDINGS,:187-192 2000
Author:N Hayashida; T Yakoh; T Murakami; K Ohnishi
Abstract:A novel method of friction compensation based on twin drive system is discussed in the's peeper. The twin drive system in. composed of two motors connected by a differential mechanism. Then the generated torque of the system is the torque difference between two motors. Also these motor's are continuously driven to reduce the influence of static friction in each motor even, if the system has a stationary motion. This is one of the remark able points in the proposed approach of twin drive system. Furthermore this paper introduces virtual coordinates to construct the controller. The validity of the proposed system is confirmed by several experimental results.


An approach to biped robot with parallel mechanism
6TH INTERNATIONAL WORKSHOP ON ADVANCED MOTION CONTROL, PROCEEDINGS,:537-541 2000
Author:M Morisawa; T Yakoh; T Murakami; K Ohnishi
Abstract:This paper describes a 3 dimensional biped robot whose each leg is composed of a novel 6-DOF(degree of freedom) parallel mechanism. The proposed mechanism is suited to walk, and a total weight of each leg is expected to be lighter than serial linked biped robot. This is one of the remarkable features of the proposed mechanism. One side leg consists of three linked arms. Each arm has two active and four passive joints, and is placed in the same direction. There are two kinds of arms whose positions of the active joints are different. Thus, the robot can move without interference of each arm. In this paper, theorical analysis of the biped robot motion with parallel mechanism is shown. Furthermore a 3D dynamic simulator is developed to implement sever(II simulations. To confirm the feasibility of the proposed mechasnim, the walking motion is tested by the developed simulator.


Control of a wheeled mobile robot with two image processing grades
6TH INTERNATIONAL WORKSHOP ON ADVANCED MOTION CONTROL, PROCEEDINGS,:586-589 2000
Author:T Nakashima; T Yakoh; T Murakami; K Ohnishi
Abstract:This paper proposes a new method for trajectory planning of a mobile robot with 3D image processing. Recent advances of computer technology make it possible to realize a real time feedback of visual information in motion control system. in the almost all methods, it is assumed that environment and/or shape of obstacles are given. In the practical implementation, however, this assumption resricts the robot motion to realize a desired task. To address the above issue, this paper introduces level Set Method(LSM) to recognize 3D shape of unknown obstacle. The proposed approach has a simplified image porocessing and is easily applicable to motion control of the mobile robot.


New representation of systems with effect variables
6TH INTERNATIONAL WORKSHOP ON ADVANCED MOTION CONTROL, PROCEEDINGS,:216-221 2000
Author:K Ueno; T Yakoh; T Murakami; K Ohnishi
Abstract:This paper describes a study for a no vel system representation. The considered system is composed of several elements that have interaction among them. In the system representation, the conventional approach has been paying attention to the elements expressing a system. Hen! the proposed approach focuses on the system interactions from a viewpoint of system connection. To describe the hierarchical structure of the dynamical system connections, this paper introduce an additional variables, called "effect" variables. Then system matrices land equations are derived using "effect" variables. This feature makes it easy to design a new system.


A Temporal Data Accumulation System from a Distributed Observation Network
Proc. of International Conference on Industry, Engineering and Management Systems 1999(Mar.)
Author:矢向高弘
Abstract:コンピュータネットワークを活用して多地点の観測データを高速に回収するための手法を提案し、シミュレーション評価により有効性を示している。


μ-PULSER: A Reactive Operating System for Personal Robots
System and Computers in Japan,26(4):1-10 1995
Author:矢向高弘; 菅原智義; 安西祐一郎
Abstract:上記論文の英訳である。


開放型分散ロボット環境における無線パケット通信のための動的なタイムスロット割り当て機構
日本ロボット学会論文誌,Vol.12(No.8):1-9-87 1994(Nov.)
Author:矢向高弘; 岩沢透; 安西祐一郎
Abstract:無線パケット通信を行う場合、パケットの衝突が避けられず、タイムスロットを割り当てるのが一般的であるが、そのタイムスロット割り当てを開放環境で利用できるように拡張している。


A server-client version of “Genomatica” integrated genome information browser
Proc. of Genome Informatics Workshop, V,5:202-203 1994(Oct.)
Author:秋山泰; 矢向高弘; 森浩禎; 小笠原直毅
Abstract:ゲノムデータベースとブラウザとをサーバクライアントモデルの通信型システムとして構築することにより、常に最新のデータを閲覧できるシステムを開発している。


μ-PULSER: パーソナルロボットを構築するためのリアルタイムオペレーティングシステム
電子情報通信学会論文誌,Vol.J77-D-I(No.2):207-214-214 1994(Feb.)
Author:矢向高弘; 菅原智義; 安西祐一郎
Abstract:オペレーティングシステムPULSERを、マイクロカーネル技術を用いて再実装することにより、システムの動的な構成変更が可能となり、ロボットハードウェアの構成変更に対応できるようにしている。


PULSER: リアクティブシステムの構築に適したオペレーティングシステム
日本ソフトウェア科学会論文誌コンピュータソフトウェア,Vol.11(No.1):23-35-35 1994(Jan.)
Author:矢向高弘; 菅原智義; 安西祐一郎
Abstract:ロボット用のソフトウェアには、リアクティブなソフトウェア、生成的なソフトウェア、対話的なソフトウェアが混在する。それらを適切にスケジューリングするオペレーティングシステムを提案、開発し、性能評価を行っている。


A NEW REACTIVE OPERATING SYSTEM FOR HUMAN-ROBOT INTERACTION
ADVANCED ROBOTICS,8(4):371-383 1994
Author:T YAKOH; Y ANZAI
Abstract:Robots which interact and cooperate with humans are required to be sensitive to changes of their surrounding environment for handling physical resources and supporting open and distributed human-robot-computer systems. But it is difficult to incorporate sensitivity into real-time systems, and to identify the owner of a physical resource in an open and distributed human-robot-computer society. In this paper, we formulate a physical ownership model which is a possible solution to the managing of physical resources among humans and robots. Then we present a reactive operating system PULSER which supports the implementation of the model. A new interrupt mechanism is proposed to support sensitivity with real-time facility and a physical resource manager is implemented to support the ownership model. Also, we describe a new facility for wireless communication in open and distributed systems.


Physical Ownership and Task Reallocation for Multiple Robots with Heterogeneous Goals
Proc. of International Conference on Intelligent and Cooperative Information Systems,:80-87 1993(May)
Author:矢向高弘; 安西祐一郎
Abstract:物理共有資源の排他制御問題の定式化と、それを解決しながら資源の交換を行いあうロボット制御システムの実装を行っている。


DESIGNING INTERFACES OF AUTONOMOUS AGENTS
HUMAN-COMPUTER INTERACTION, VOL 2,19:86-91 1993
Author:T YAKOH; N YAMASAKI; Y ANZAI
Abstract:自律的なエージェントのインタフェースを設計するための要因である感受性、モデル、表象についての分析を行い、自律移動ロボットの効果的なインタフェースを実装している。


MACS - AN EFFICIENT MULTICAST MECHANISM FOR RADIOPACKET COMMUNICATION AMONG MULTIPLE MOBILE ROBOTS
IEEE PACIFIC RIM CONFERENCE ON COMMUNICATIONS, COMPUTERS AND SIGNAL PROCESSING : PROCEEDINGS, VOLS 1 AND 2,:561-564 1993
Author:T YAKOH; T IWASAWA; Y ANZAI
Abstract:無線パケット通信におけるタイムスロット割り当てアルゴリズムを開放環境で利用できるように拡張した通信機構MACSを実装し、性能評価を行っている。


PULSER - A SENSITIVE OPERATING SYSTEM FOR OPEN AND DISTRIBUTED HUMAN-ROBOT-COMPUTER INTERACTIVE SYSTEMS
IEEE INTERNATIONAL WORKSHOP ON ROBOT AND HUMAN COMMUNICATION : PROCEEDINGS,:404-409 1992
Author:T YAKOH; T SUGAWARA; T AKIBA; T IWASAWA; Y ANZAI
Abstract:人間とのインタラクションを行うロボット用のオペレーティングシステムPULSERを開発し、その性能評価を行っている。


講演・口頭発表等
Uncertainty Principle in Real-Time Communication - Battle of Quickness against Correctness in NBCS -
先進的運動制御に関する国際ワークショップ 2012(Mar. 25)
Presenter:矢向 高弘


コンピュータネットワークを用いた広域制御
日本機械学会 運動と制御研究会(MOVIC) 1999(Nov.)
Presenter:矢向高弘
Abstract:コンピュータネットワークによる実時間通信の可能性を示すとともに、広域制御の具体的な応用例を紹介した。


MISC
学界情報 国際会議レポート
電気学会論文誌D,132(7):PNL7-4 2012(Jul. 01)
Author:矢向 高弘


最適分散動的量子化器に基づく帯域制限を伴う加速度制御
電気学会研究会資料. IIC, 産業計測制御研究会,2012(133):25-30 2012(Mar. 06)
Author:矢代 大祐; 矢向 高弘


帯域変動を伴う視触覚通信のための端末間フロー制御
電気学会研究会資料. IIC, 産業計測制御研究会,2011(25):11-16 2011(Mar. 08)
Author:矢代 大祐; 矢向 高弘


Bilateral teleoperation through networks
IEEJ Transactions on Industry Applications,126(2):161-167 2006
Author:Kenji Natori; Toshiaki Tsuji; Takahiro Yakoh; Kouhei Ohnishi
Abstract:Nowadays haptics (tactile sensation) is receiving much attentions. To transmit a vivid tactile sensation, real-time processing is necessary. In these circumstances, time delay caused in networks or some devices is a very serious problem. Therefore in this paper, influence of time delay on bilateral systems for haptics is examined. At first, the influence is verified by the analysis based on an evaluation index "Transparency". Characteristic behavior of time delay can be found out. Then experimental results via the network between Shinanomachi and Yagami campus (Keio University) are shown. Transmission of vivid tactile sensation of remote environment is realized.


ネットワークを介したバイラテラル遠隔操作
電気学会研究会資料. IIC, 産業計測制御研究会,2005(16):41-46 2005(Mar. 09)
Author:名取 賢二; 辻 俊明; 矢向 高弘; 大西 公平


分散リアルタイムネットワーク
日本機械学會誌 = Journal of the Society of Mechanical Engineers,106(1021):944-945 2003(Dec. 05)
Author:矢向 高弘; 西 宏章


分散リアルタイムネットワーク
日本機械学会誌,106(1021):36-37 2003(Dec.)
Author:矢向 高弘; 西宏章


力制御に基づいた移動ロボットによる対象物の運動制御
電気学会研究会資料. IIC, 産業計測制御研究会,2000(1):109-114 2000(Mar. 10)
Author:矢嶋 達生; 矢向 高弘; 村上 俊之; 大西 公平


移動ロボットにおけるマルチタスク処理を用いたヒューマンアクティブフィードバックシステムの一考察
電気学会研究会資料. IIC, 産業計測制御研究会,1999(1):33-38 1999(Jan. 14)
Author:矢嶋 達生; 矢向 高弘; 村上 俊之; 大西 公平


人間とマルチロボットを含む物理世界計算システムの提案
日本機械学会ロボティクス メカトロニクス講演会論文集,:63-68 1992
Author:矢向高弘

特許等知的財産
登録済特許
情報処理システム,制御装置,検出装置,情報処理方法,制御方法,検出方法,及びプログラム
マスタスレーブ装置,マスタ装置,スレーブ装置,制御方法及びコンピュータプログラム
マルチメディア通信装置
電気レオロジー素子およびこれを備えた電気レオロジーデバイス
フリクションフリードライブシステム