Standing assistance considering a voluntary movement and a postural adjustment

In this paper, we propose a standing assistance scheme that uses a patient's own physical strength. In the previous researches, conventional assistive robots do not require patients to use their own physical strength to stand, which leads to decreased strength in the elderly. Therefore, an assistive robot that allows a patient to maximally use their remaining physical strength is desired. For realizing this objective, we propose a standing assistance scheme that realizes two functions, one is a motion assistance function using a patient's own physical strength, and the other is postural adjustment function. In general, a human movement consists of a voluntary movement which mainly generates the body motion and a postural adjustment which keeps the body stability during the motion. Our proposed scheme assists with the minimum force that enables the voluntary movement with their remaining physical strength and keeps the body stability according to their postural adjustment. For realizing two different approaches in same time, we propose a body movement vector for dividing a human motion into a voluntary movement and a postural adjustment. Using the proposed idea, our prototype assistive robot can help elderly patients to stand using their remaining physical strength maximally by two assistive functions.