In recent years, a rapid increase in bedridden elderly, due to cerebral strokes and other diseases, has become a social problem due to soaring medical costs and heavy burden of long term care support. Therefore, development of walk rehabilitation devices for the elderly, suffered from cerebral strokes, is strongly expected. In the research so far, the authors have developed a rollator with a chest support pad that can rotate freely with one degree of freedom, and the effectiveness of its walk assistance was evaluated. In this study, a novel rollator using a motor-driven chest support pad was developed. A compact system to combine data collect system and motor control was configured. Walk measurements for six subjects were conducted using the developed rollator. The relationship between the movements of the lower limbs and rotation of the motor driven chest support pad was investigated. Time series and power spectrum results were analyzed, and the effectiveness of the motor-driven chest support pad on movement of the lower limb during walking was discussed.

Cooperative control algorithms for a redundant finger-arm robot were proposed in a previous study, based on the movement of the human hand-arm system. With these algorithms, the finger-arm robot arm was able to complete a constrained task by integrating admittance control and impedance control with the manipulability control of the fingers. The manipulability of the fingers was controlled using both an approximate global search (i.e., the top search method) and a local optimization method. However, the dynamic characteristics of these methods have not yet been studied. In this study, the conventional cooperative control algorithms were developed further by extending them to dynamic movement in the admittance control of a redundant multi-finger-arm robot with manipulability control of the fingers. We clarified the relationship between the feasibility of the virtual dynamics and the motion speed, as well as the range of the achievable virtual dynamics. This paper evaluates and discusses the proposed methods in terms of the finger manipulability control. The experimental results show that the algorithms responded to more dynamic movement, and a broader range of virtual dynamics was achievable.

This paper deliberates the spatial cognitive ability of the moving distance of the human hand, which is measured by using motion capture. Before the movement begins, the subject is shown a standard length. Then, both horizontal and vertical blindfold hand movements were measured using the proposed protocol for six right handed subjects in order to investigate the cognitive ability of the moving distance of the human hand. The experimental results show that the average moving distances obtained in both directions were quite smaller than the standard length an inverse "V" pattern in percentage result was observed only in the horizontal movement. The experimental result also demonstrated an interesting relationship between the hand moving distance and manipulability of the upper limb. © 2007 IEEE.

This paper investigates the motion forms of robots generated by the Q-Learning algorithm during the learning process. We analyzed the manner in which a caterpillar robot, which performs looping motions using two actuators, acquires advance actions by focusing on the process. By observing a series of processes, we confirmed that various motion forms appeared or disappeared as a result of their interactions with the learning process and approach an optimum motion form. In most algorithms, such motion forms cannot appear in the learning process because its framework is almost predetermined by the teacher data, and the cost functions for learning cannot be usually considered as a continuous process. The characteristics of reinforcement learning are very interesting from the viewpoint of biological evolution. This paper describes the effects of the interaction between the robot kinematics and the environment as a direct result of changing the environment. In addition, this study challenged the acquisition of two-dimensional motions with a starfish robot having four actuators. The result demonstrates that the robot can obtain a reasonable motion from the complicated relationships with the environment by skillfully employing its structure. Moreover, this paper implies that the reward manipulation may give a new insight for the learning process by the investigations performed in this study. This paper examines the possibility of the reward combinations for generating arbitrary motions.

The advancement of multimedia services including audio/visual media has been rapid. The applications of cellular phones, in particular, have increased by using these technologies. In addition, if force telecommunication were realized, force information would become a next leading factor in the multimedia service. In this field, a robotic master/slave system is a leading candidate. This system has been studied as a teleoperation system between an operator and an environment; the operator controls only the master device whereas the slave device is never controlled. For multimedia applications, such systems require flexibility and bidirectionatity because force telecommunication must consider the interactions between users. This paper details the fundamental issues of force communication from a viewpoint of human perception. With regard to the control system, this study uses an integrated hybrid control master/slave system that helps to find a key factor of equal bilateral force telecommunication in the sensory aspect. The employed system has a function to change the proportion of force display to position display by varying a weight parameter. We discuss the basic control performance of a force telecommunication system and evaluate qualitative feelings of users by using a psychological evaluation method.

The main advantage of Reinforcement Learning is that it provides unexpected solutions for a designer. This study shows how a mobile robot can obtain unexpected motion forms by using Reinforcement Learning. Results show the the mobile robot with two-dimensional mobile ability can obtain unexpected motion forms for both advance motion and rotation motion. The mechanisms for these motions were investigated in order to understand how to obtain these motions. Moreover, since this system has a two-dimensional factor, this study examines the learning characteristic for the oblivion of the learning knowledge. In addition, this study examines the learning of the knowledge manipulation method to obtain new learning results with respect to the two-dimensional factor.

脳卒中患者のリハビリテーションとしてトレッドミルによる歩行訓練を行うという手法は臨床的に広く用いられてきたが、現行の歩行訓練機器のほとんどは利用者下肢部に注目し、下肢部の反復強制運動を行うものである。一方、申請者らはこれまでに１自由度回転機構付きの胸部支持パッドを有する歩行車を試作し、歩行運動の特徴を定量的に評価した。利用者は提案の歩行車で歩行する際に、胸部支持パッドの回転により利用者腰部のスイングが自然に引き出され、ベルトを介して足が引っ張られることによって利用者の歩行意欲の向上を図りながら、歩行のリズム感をつかめやすいという特徴がある。そこで本研究は、これまでの研究成果を活かして、回転型胸部支持パッドを有するトレッドミル型歩行訓練機の開発を行い、その効果を評価することを目的とする。 本年度は研究計画の初年度であり、まずハードウェアの設計製作を含めたシステムの開発に取り組む。従来の研究成果を参考しながら、身長180cm、体重100kgまでの人が利用可能な回転型胸部支持パッドとその周辺支持機構を設計・試作したのち、市販品のトレッドミルに取り付けることによって回転型支持パッドを有するトレッドミル歩行訓練機器のハードウェアを製作した。また、歩行中利用者の運動情報を測定するため、支持パッドへの圧力を測る力センサと、歩行者下肢部の運動を測定するゴニオメータなどのセンサを用いており、これらのセンサ情報を集計するための計測系を構築した。本年度の研究内容に係わる研究発表については、学術講演会で２件の発表実績があった。

本研究では、利用者の歩行意欲を能動的に促進できる駆動型胸部支持パッドを有する歩行車の開発を行った。試作した歩行車では、身長180cm、体重100kgまでの利用者を想定して設計されており、支持パッドに力センサ4個を取り付けることで体重による圧力を計測できる。また、駆動モータの制御系とセンサ計測系を連動するためのシステム構築を行い、さらに外部電源のコードレス化を実現した。歩行車補助効果の評価としては、膝伸展角および足首回転角度の変動が胸部支持パッドの回転と連動していることがパワースペクトル解析によって明らかになっており、相関係数の結果から下肢部の運動が支持パッドの回転と強く関連したことが示された。