Design and PID Control of Tendon-Driven Continuum Robot for Finger Rehabilitation

The adoption of robots in rehabilitation has seen a substantial rise, affirming their efficacy in facilitating recovery. Nonetheless, a notable gap exists in the market for products specifically tailored to assist with finger rehabilitation. Tendon-driven continuum robots (TDCRs) emerge as flexible robotic systems designed to emulate the properties of tendons and muscles. Comprising deformable segments connected through tendons or cables, these robots can flex, twist, and elongate. This structural configuration positions TDCRs as promising technological solutions for delivering heightened sensitivity and precision in the realm of finger rehabilitation. This study presents the design of a tendon-driven continuum robot (TDCR) as a wearable device tailored for patients requiring intensive finger rehabilitation. The developed robot facilitates intensive rehabilitation by leveraging more than 12 degrees of freedom (DoF) to provide individual actuation capabilities for each phalanx and joint. This design allows for abduction-adduction movements, as well as contraction-expansion, distinguishing it from previously developed active or passive hand exoskeletons. To assess the performance of the TDCR, we implemented a proportional-integral-derivative (PID) controller within a multibody model and simulation environment. Experimental evaluations focused on examining the motion of the distal interphalangeal (DIP), metacarpophalangeal (MCP), and proximal interphalangeal (PIP) joints. The results demonstrate that the phalanges effectively followed the desired reference, indicating the potential utility of TDCR in the field of finger rehabilitation.