Development of Wrist Interface Based on Fully Actuated Coaxial Spherical Parallel Mechanism for Force Interaction

Area of Science:

• Robotics and Mechanical Engineering
• Biomechanics and Human-Machine Interaction

Background:

• Developing wrist robotic exoskeleton interfaces (REIs) for force interaction requires a large range of motion, high torque output, and low inertia.
• Existing REIs may not fully replicate human wrist capabilities for dynamic motion response and natural interaction.

Purpose of the Study:

• To propose and develop a wrist REI based on a fully actuated coaxial spherical parallel mechanism (FC-WREI).
• To achieve a device with pure rotational motion, high torque synthesis, and low moving parts inertia, mimicking human wrist functionality.

Main Methods:

• Design and implementation of a fully actuated coaxial spherical parallel mechanism (CSPM) for the wrist exoskeleton.
• Mechanical design optimization and analysis to achieve desired performance characteristics.
• Experimental validation of torque output, range of motion, and inertia compared to human wrist capabilities and similar devices.

Main Results:

• The FC-WREI provides a torque output of 56.49-130.43% of the maximum human wrist isometric torque.
• The device ensures a consistent range of motion without interfering with natural human wrist movement.
• The inertia of the FC-WREI is up to 5.35 times lower than comparable existing devices.

Conclusions:

• The proposed FC-WREI successfully meets the requirements for wrist force interaction REIs.
• Its mechanical advantages, including pure rotation, high torque, and low inertia, make it suitable for diverse applications.
• The FC-WREI demonstrates significant improvements over similar devices, enhancing its applicability in human-robot interaction.