Extension motion assistance for upper limb using Proxy-Based Sliding Mode Control

Many people of all ages have sustained cervical cord injury in traffic accidents, falls, or sport accidents, which has resulted in their physical impairment. Among such individuals, dysfunction of the upper limb is of particular concern, even though recovery from dysfunction is possible through rehabilitation. In this study, we developed a wearable assistive robot for the upper limb; this robot can be used to perform various tasks involving upper limb motion in daily life. To achieve this, we devised an algorithm for assisting extension motion. Individuals with C5-level Cervical Cord Injury (CCI) cannot perform extension of the elbow on their own. Therefore, we calculated the reference velocity curve and the angle of extension only from the force in the direction of flexion. In this way, the wearer can autonomously adjust the movement.