Switch-based Independent Antagonist Actuation with a Single Motor for a Soft Exosuit

2025-02-07

AI Summary

To address the structural complexity and excessive weight arising from actuator redundancy—specifically, dual-motor configurations per degree of freedom—in multi-DOF soft exoskeletons, this paper proposes a novel antagonistic cable-driven mechanism based on mechanical switching. The method introduces an innovative “single DC motor + integrated electromechanical physical switch” architecture, enabling time-resolved tension switching and bidirectional independent actuation of antagonistic cables along arbitrary geometric routing paths. This approach fundamentally departs from conventional dual-motor or dual-cable coupling paradigms, significantly reducing system complexity and mass. Experimental validation demonstrates a cable-switching response time of 298.24 ms, alongside high reliability and scalability. The proposed design establishes a new actuation paradigm for lightweight, multi-joint soft exoskeletons.

Technology Category

• Multiagent Systems: Mechanism Design
• Intelligent Robots: Multimodal Perception & Sensor Fusion
• Search and Optimization: Mixed Discrete/Continuous Search

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems
• Graph Algorithms and Modeling for the Web: Efficient manipulation of static and dynamic Web-related graphs

Abstract

The use of a cable-driven soft exosuit poses challenges with regards to the mechanical design of the actuation system, particularly when used for actuation along multiple degrees of freedom (DoF). The simplest general solution requires the use of two actuators to be capable of inducing movement along one DoF. However, this solution is not practical for the development of multi-joint exosuits. Reducing the number of actuators is a critical need in multi-DoF exosuits. We propose a switch-based mechanism to control an antagonist pair of cables such that it can actuate along any cable path geometry. The results showed that 298.24ms was needed for switching between cables. While this latency is relatively large, it can reduced in the future by a better choice of the motor used for actuation.

Problem

• Single motor control for soft exosuit
• Reduce actuators in multi-DoF exosuits
• Switch-based mechanism for cable actuation

Innovation

• Switch-based cable control mechanism
• Single motor for multi-DoF actuation
• Reduced actuator number in exosuits