Standing assistance which realizes voluntary movements of the patient within a safety motion tolerance

Abstract

This paper proposes a novel standing assistance robot, which realizes voluntary movements of the patient within a safety motion range. In previous studies, conventional assistive robots did not require patients to use their own physical strength to stand, which leads to decreased strength in the elderly. Such general assistive robots helped patients by using a fixed motion reference pathway in spite of their original intention, and as a result, these robots failed to use the physical strength of the patients. Therefore, we have clarified the range of motion that allows patients to move their body safely and applied this safety tolerance for assistive robot control. However, determining whether a patient's movements are within a safe tolerance may not be enough to successfully assist the patient. For example, the robot should assist its patient immediately if the patient falls down even if this motion is done within safety tolerance. Thus, in this paper, we extend from our previous safety tolerance to safety "motion" tolerance. Furthermore, we implement this idea to our assistive robot control using damping control algorithm. Proposed idea is implemented to our new prototype and its effectiveness is verified by experimental results with elderly subjects who lives in the nursing care house.