PROJECT TITLE :

Human–Robot Interaction Control of Rehabilitation Robots With Series Elastic Actuators

ABSTRACT:

Rehabilitation robots, by necessity, have direct physical interaction with humans. Physical interaction affects the controlled variables and could even cause system instability. Therefore, human-robot interaction management design is vital in rehabilitation robotics analysis. This paper presents an interaction control strategy for a gait rehabilitation robot. The robot is driven by a completely unique compact series elastic actuator, that provides intrinsic compliance and backdrivablility for safe human-robot interaction. The management style is predicated on the actuator model with consideration of interaction dynamics. It consists mainly of human interaction compensation, friction compensation, and is enhanced with a disturbance observer. Such a management theme permits the robot to attain low output impedance when operating in human-in-charge mode and achieve correct force tracking when operating in force management mode. Due to the direct physical interaction with humans, the controller style should additionally meet the steadiness demand. A theoretical proof is provided to point out the guaranteed stability of the closed-loop system underneath the proposed controller. The proposed style is verified with an ankle robot in walking experiments. The results can be readily extended to different rehabilitation and assistive robots driven with compliant actuators while not a lot of issue.