Control method of a human support robot for independent living by center of gravity information of upper body

Abstract

For the patients with disabled lower limbs, independent living is difficult to perform and the subsequent lack of physical exercises of their upper body in daily life may cause disuse syndrome. In order to assist the patients to live independently and exercise their upper body in daily life, a human support robot (HSR) is developed, and a novel control method, using the upper body gravity information, is proposed to control the HSR. Based on the information of upper body's center of gravity(COG), the HSR can move according to the user's intention. Under the assistance of the HSR, patients can move to any direction by shifting their upper body. Four force sensors are used to measure the user's weight distribution. Through analyzing the force data from 4 sensors, user's motion intention can be inferred by the proposed intention recognition method, and then it is used to control the HSR to move in the intended velocity. To distinguish the moving intention and the stationary intention, a parameter of intention strength is introduced. At last, an experiment is conducted to verify the performance of control method.