A challenge: Support of standing balance in assistive robotic devices

Abstract

Neurological patients using a powered lower-body exoskeleton for rehabilitation of standing and walking skills in an upright body pose face the safety challenge of postural instability and fall. Current research, therefore, develops exoskeletons with self-balancing functions. This study suggests basing the exoskeleton's stabilization of standing posture on a human-derived postural control mechanism. A corresponding control system has previously been successfully tested with specific balancing tasks in humanoid robots. Here, we provide a short introduction into the control method and, using a lightweight robot, present as a test of the balancing an experimental shift in the body weight distribution (as if, e.g., a human exoskeleton user was raising an arm or leaning the upper body or lifting an external weight). An overview of other specific balancing tests previously already investigated in humans and humanoids is also briefly mentioned. Overall, the tests will allow the quantification of the capabilities of self-balancing exoskeletons developed for patients with partial paralysis of lower body sensorimotor functions.