Abstract
User security is an important consideration for robots that interact with humans, especially for upper-limb rehabilitation robots, during the use of which stroke patients are often more susceptible to injury. In this paper, a novel safety supervisory control method incorporating fuzzy logic is proposed so as to guarantee the impaired limb's safety should an emergency situation occur and the robustness of the upper-limb rehabilitation robot control system. Firstly, a safety supervisory fuzzy controller (SSFC) was designed based on the impaired-limb's real-time physical state by extracting and recognizing the impaired-limb's tracking movement features. Then, the proposed SSFC was used to automatically regulate the desired force either to account for reasonable disturbance resulting from pose or position changes or to respond in adequate time to an emergency based on an evaluation of the impaired-limb's physical condition. Finally, a position-based impedance controller was implemented to achieve compliance between the robotic end-effector and the impaired limb during the robot- assisted rehabilitation training. The experimental results show the effectiveness and potential of the proposed method for achieving safety and robustness for the rehabilitation robot.
Highlights
Neurologic injuries such as strokes and spinal cord injuries (SCI) cause dysfunction to the neural system and motor function, which generally results in upper‐limb impairment and motion disabilities [1, 2, 3]
Due to the particular conditions of the participants, safety and robustness are strongly addressed in controller design, which has been a critical issue for the rehabilitation robot
A real‐time control system based on a safety supervisory strategy is designed, which mainly involves evaluating the physical state of the training impaired limb (PSTIL), a supervisory fuzzy controller (SSFC) and a position‐based impedance controller
Summary
Neurologic injuries such as strokes and spinal cord injuries (SCI) cause dysfunction to the neural system and motor function, which generally results in upper‐limb impairment and motion disabilities [1, 2, 3]. D10B,a1o2g7u:o20X1u3: 1 Safety Supervisory Strategy for an Upper-Limb Rehabilitation Robot Based on Impedance Control emergency situations, an emergency‐stop button and some specialized mechanical structures have been designed. The designed control system should combine robustness and safety, and be able to effectively manage reasonable disturbances and sudden emergencies. A real‐time control system based on a safety supervisory strategy is designed, which mainly involves evaluating the physical state of the training impaired limb (PSTIL), a SSFC and a position‐based impedance controller. The proposed SSFC makes decisions to adapt the desired force in response to reasonable disturbances, or to quickly stop the rehabilitation robot without doing harm to the training impaired limb when it suffers from a sudden spasm or twitch. Considering the essential characteristics of the PSTIL, the developed control system effectively combines robustness and safety and will perform a better rehabilitation exercise
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
