A power-assisting device is being developed to help older persons and people with disabilities move themselves from beds to wheelchairs. The device is intended to contribute to a more independent life for these people and to greater utilization of their latent abilities. Self-support assistance, i.e., the support provided by a power-assisting device to the person without the need for aid from a caregiver, and capability of the device to assist the movements of the people are discussed. A method for the production of power assistance and motion guidance is then proposed for the device. Finally, a test of the performance of the developed system is described.

A power-assisting device is presented to help elderly patients and patients with disabilities transfer themselves from beds to wheelchairs. The device is intended to contribute to a more independent life for the patients and to greater utilization of their disabilities. The development of the device, which consists of an upper part capable of motion in a horizontal plane and a lower part capable of motion in a vertical plane, is discussed. The production method for the power assistance and motion guidance of this device is proposed. Finally, the testing of the performance of the developed system in a basic experiment is described.

We developed a robotic orthosis capable of helping human forearm motion. This orthosis was carefully designed such that mechanical safety for human beings could be ensured. A power assist control scheme for the robotic orthosis is proposed. The performance of the developed system is examined by several experiments.

When two robot arms holding an object together they form a closed kinematic chain which enables generation and control of arbitrary internal forces on the object. The internal forces balance within the closed kinematic chain and therefore do not contribute to the resultant force that generates motion. However, they change the effective compliance realized on the object. Therefore when the object held by the robots makes a contact with a rigid environment the compliance at the contact location does not only depend on the inherent compliances and the posture of each robot arm but also depends on the internal forces exerted on the object. In cases when the contact location moves relative to each robot's tip, the compliance at the contact depends also on the variation of the contact location. In this study we propose a method that utilizes the internal forces to keep the contact compliance in primarily important directions close to the desired values regardless of the variation of the contact location and robots' posture.

This paper proposes a cooperative control scheme of dual-arm robots, which produces a reasonable pair of the two endpoint motions of the arms for a given relative motion. A dual-arm system with a linear motion is discussed, and the principle of the control scheme is presented. The redundancy of the system and the problem of the motion distribution are explained. The concept of the absolute motion which represents the total motion of the system is introduced, and a cooperative control scheme of dual-arm robots is proposed, using this absolute motion. Basic equations are presented and a cooperative control scheme of dual-arm robots with six degrees of freedom is proposed. Finally, several simulation and experimental results are given to illustrate the validity of the proposed control scheme.

When a mechanism is overconstrained it leads to the generation of internal forces. These forces do no work but have an effect on the apparent structural stiffness of the mechanisms. The degree of this effect depends on the magnitude or the mode of the internal forces and the geometry of the mechanisms. Internal forces may result from external or gravitational forces or the inertial loads during motion. If a mechanism has a closed chain structure, the redundant actuation may generate internal forces as well. -. . 'o The authors analyse the apparent structural stiffness of the closed mechanisms due to redundant actuation and the forces arising during dynamic motion.>

A control scheme for pneumatic drive systems is proposed. In general, static friction, Coulomb friction, and other nonlinear disturbances crucially worsen the performance of pneumatic drive systems. In the proposed control scheme, to guarantee robustness against such disturbances and stability of the motion, position feedback loops and pressure feedback loops are hierarchically connected. The stability of the motion is investigated by using a Lyapunov function. As a result, it is mathematically proven that the motion of pneumatic drive systems converges to a fixed desired point as time tends to infinity, even if the disturbances affect the motion. The effectiveness of this control scheme is demonstrated through some experimental results.>