Trajectory estimation of a skid-steering mobile robot propelled by independently driven wheels
Tokuji Okada; Abeer Mahmoud; Wagner Tanaka Botelho; Toshimi Shimizu, This paper analyses a mobile robot with independently rotating wheels travelling on uneven but smooth ground, including ascending or descending surfaces. We formulate a mathematical expression for the energy cost of the robot's movement. For our analysis, we utilise the principle of virtual work and assume that the robot moves with a fixed arrangement of wheel axes and without using a steering handle. The mathematical model reveals that the coefficient of friction and the payload distribution dominate the wheel behaviour, including slipping and skidding. We minimise the virtual work expression to determine the robot's motion complying with driven wheels. The model also enables us to estimate trajectories for different ground conditions. A hybrid robot, PEOPLER-II, is used to demonstrate the predicted motions, including turns and spins, by following angular velocity control rules. Experimental data verifies that the proposed formulation and minimisation of virtual work are valid techniques for predicting a robot's trajectory. The method described is widely applicable to wheeled robots having independently driven wheels., CAMBRIDGE UNIV PRESS
Robotica, 2012

Passivity based control for a magnetically levitated flexible beam with rate estimation via the extended Kalman filtering technique
Toshimi Shimizu; Minoru Sasaki; Tokuji Okada, Lead, This paper presents a passivity based control method combined with velocity estimation by an extended Kalman filter for a magnetically levitated flexible beam with both ends free by two electromagnets. An energy-based analysis concludes that the system can be decomposed into two passive subsystems: a mechanical subsystem consisting of the flexible beam and an electrical subsystem consisting of the electromagnets. We designed a passivity based controller independently for each subsystem. An output feedback controller for the mechanical subsystem computes the desired force that is required to achieve position convergence and vibration suppression of the flexible beam. A feed forward controller for the electrical subsystem computes the input voltage for the electromagnets to generate the desired force. In a practical point of view, structural and economic considerations restrict simultaneous usage of both position sensors and velocity sensors while the control strategy requires accurate measurements of the position and velocity of the flexible beam. We employ the extended Kalman filtering technique in order to estimate the velocity of the flexible beam from the measured micro-displacement vibration at a high sampling frequency. Effectiveness of the proposed controller and velocity estimator is demonstrated by a numerical simulation., IOS PRESS
International Journal of Applied Electromagnetics and Mechanics, 2011

Control of a two-link flexible manipulator using an artificial immune system and an adaptive neural network　　　　　　　　　　　　　　　
日本AEM学会誌, 2011, [Reviewed]

Motion Analysis with Experimental Verification of the Hybrid Robot PEOPLER-II for Reversible Switch between Walk and Roll on Demand
Tokuji Okada; Wagner Tanaka Botelho; Toshimi Shimizu, We propose a newly renovated mobile robot PEOPLER-II (Perpendicularly Oriented Planetary Legged Robot), and addresses its motion analysis for switching its locomotion from leg-type to wheel-type and vice versa. For the leg-type locomotion, particularly in a transitional state of sitting or standing, we propose a control method based on minimization of the total energy cost using the distribution of the motor power payload in the hip and knee joints, in addition to the method of keeping the same payload factor. Also, we discuss robot configurations for switching between the two locomotion types by considering environmental factors such as walking gaits, ground inclination angle and robot's traveling direction. Knee joint position of a pivotal foot determines knee ahead and knee behind gaits. In each switch, we check such characteristics as the hip joint rotation direction, robot center trajectory, and necessary total power in a practical point of use. Then we build three beneficial switching cycles aiming for moderate use of a motor, rider's comfort, and power saving. Finally, we demonstrate the switching by considering the aim and verify that the results of the analysis become useful for enabling switching on demand., SAGE PUBLICATIONS LTD
International Journal of Robotics Research, 2010

ロボット数式処理　　　　　　　　　　　　　　　
Haruhisa Kawasaki and Toshimi Shimizu, Joint work
昭晃堂, Nov. 2000

連続時間システムに対する強化学習を用いた1 自由度柔軟リンクロボットアームの制御　　　　　　　　　　　　　　　
上木 武流、清水 年美
システムインテグレーション部門講演会, 15 Dec. 2021, 計測自動制御学会
20211215, 20211217

筋骨格ロボットの運動と剛性の制御　　　　　　　　　　　　　　　
山床優太,清水年美
茨城講演会, 19 Aug. 2021, 日本機械学会
20210819, 20210819

アクタークリティック法による１自由度柔軟リンクロボットアームの制御　　　　　　　　　　　　　　　
安本有輝; 清水年美
2019年度茨城講演会, 22 Aug. 2019

二つのモータを用いた二関節筋駆動機構に関する研究　　　　　　　　　　　　　　　
遠藤晋作; 清水年美; 谷口翔太
2018年度茨城講演会, 22 Aug. 2018

Boundary Control of a Thin Rectangular Plate with Clamped-Clamped-Clamped-Free Boundary Conditions　　　　　　　　　　　　　　　
Toshimi Shimizu
SICE International Symposium on Control Systems 2018, 09 Mar. 2018

二関節筋駆動機構を有するロボットアームの筋収縮力空間の直和分割　　　　　　　　　　　　　　　
山口直紀; 清水年美
2016年度茨城講演会講演論文集, 26 Aug. 2016

衝突時におけるヒト上肢筋配列模倣型ロボットアームの運動特性の研究　　　　　　　　　　　　　　　
野内雄太; 清水年美
2015年度山梨講演会, 17 Oct. 2015

Multiple Error Filtered-X LMSを用いたアクティブ遮音ケースの開発　　　　　　　　　　　　　　　
市川拓弥; 清水年美
2015年度山梨講演会, 17 Oct. 2015

動的可操作性楕円体に基づく特性評価を利用したに関節筋ロボットの適応制御　　　　　　　　　　　　　　　
関和希; 高橋治; 清水年美
2012年度山梨講演会, 27 Oct. 2012

経路モデルを必要としないハウリングフィルタ付きアクティブノイズコントロール　　　　　　　　　　　　　　　
佐藤宏樹; 清水年美
2012年度山梨講演会, 27 Oct. 2012

平面2自由度フレキシブルアームの手先位置計測システムの構築　　　　　　　　　　　　　　　
高橋和也; 森坂雄大; カナラグランス; 清水年美
2012年度山梨講演会, 27 Oct. 2012

アクティブ動吸振器を用いた超高層構造物の制振制御　　　　　　　　　　　　　　　
庄司俊哉; 清水年美
2011年度茨城講演会, 25 Aug. 2011

重力環境下における二関節筋ロボットアームの挙動解析　　　　　　　　　　　　　　　
幸西義樹; 清水年美
2011年度茨城講演会, 25 Aug. 2011

Feb. 2001, The Japan Society of Mechanical Engineers

Dec. 1996, The Society of Instrument and Control Engineers