Title
Adaptive Assist-As-Needed Control Based On Actor-Critic Reinforcement Learning
Abstract
In robot-assisted rehabilitation, assist-as-needed (AAN) controllers have been proposed to promote subjects' active participation, which is thought to lead to better training outcomes. Most of these AAN controllers require a patient-specific manual tuning of the parameters defining the underlying force-field, which typically results in a tedious and time-consuming process. In this paper, we propose a reinforcement-learning-based impedance controller that actively reshapes the stiffness of the force-field to the subject's performance, while providing assistance only when needed. This adaptability is made possible by correlating the subject's most recent performance to the ultimate control objective in real-time. In addition, the proposed controller is built upon action dependent heuristic dynamic programming using the actor-critic structure, and therefore does not require prior knowledge of the system model. The controller is experimentally validated with healthy subjects through a simulated ankle mobilization training session using a powered ankle-foot orthosis.
Year
DOI
Venue
2019
10.1109/IROS40897.2019.8968464
2019 IEEE/RSJ INTERNATIONAL CONFERENCE ON INTELLIGENT ROBOTS AND SYSTEMS (IROS)
Keywords
Field
DocType
Assist-as-needed controller, robot-assisted training, reinforcement learning, wearable robotics, rehabilitation robotics
Wearable robot,Adaptability,Control theory,Computer science,Control engineering,Rehabilitation robotics,Heuristic dynamic programming,System model,Reinforcement learning
Conference
ISSN
Citations 
PageRank 
2153-0858
0
0.34
References 
Authors
0
4
Name
Order
Citations
PageRank
Yufeng Zhang111730.05
Shuai Li202.37
Karen J. Nolan313.81
Damiano Zanotto45512.02