Technology Category
Intelligent Robots: ManipulationMultiagent Systems: Mechanism DesignGame Theory and Economic Paradigms: Mechanism Design
Design, Modelling and Experimental Evaluation of a Tendon-driven Wrist Abduction-Adduction Mechanism for an upper limb exoskeleton
🤖 AI Summary
This study addresses the challenges of conventional wrist exoskeleton actuation mechanisms—namely excessive weight, high friction, and structural complexity—by proposing a novel abduction–adduction actuation mechanism based on a single tendon cable coupled with a helical torsion spring for passive tensioning. The design leverages Bowden cable transmission and a clock spring to achieve self-tensioning without requiring antagonistic actuation. Kinematic and dynamic modeling guides the selection of spring stiffness, thereby reducing reliance on empirical tuning. Experimental validation demonstrates strong agreement between simulation predictions and actual performance trends, with the chosen spring configuration achieving a balanced trade-off among range of motion, output torque, and repeatability. These results effectively support the development and optimization of lightweight, compact cable-driven wrist exoskeletons.
Technology Category
Application Category
📝 Abstract
Wrist exoskeletons play a vital role in rehabilitation and assistive applications, yet conventional actuation mechanisms such as electric motors or pneumatics often introduce undesirable weight, friction, and complexity. This paper presents a novel single-cable (tendon), torsional-spring-assisted actuation mechanism for wrist abduction-adduction, and a simulation-based method for selecting its stiffness parameters. The mechanism employs a single Bowden cable passively tensioned by a spiral torsional spring (clock spring) to maintain continuous cable tension without antagonistic actuation. Kinematic and dynamic modeling of the mechanism was performed to estimate the required torque and identify optimal spring parameters. These simulation-derived parameters guided the design of a functional prototype, which was experimentally evaluated with five participants with no motor disabilities (NMD) under varying arm positions and loading conditions using three spring configurations to account for user variability and modeling uncertainties. Experimental results show consistent agreement with simulation-derived trends, with the nominal spring configuration achieving balanced motion range, torque demand, and repeatability. The results demonstrate that simulation-informed stiffness selection can effectively guide the design of compact, cable-driven wrist exoskeletons while reducing reliance on empirical tuning.
Problem
Research questions and friction points this paper is trying to address.
wrist exoskeleton
tendon-driven mechanism
abduction-adduction
actuation complexity
rehabilitation robotics
Innovation
Methods, ideas, or system contributions that make the work stand out.
tendon-driven
torsional spring
wrist exoskeleton
simulation-based design
cable actuation
🔎 Similar Papers
No similar papers found.
