An upper-limb teleoperation exoskeleton with stepless arm-length parameterization and adaptive force-triggered...

Area of Science:

• Robotics and Human-Machine Interaction
• Biomechanics and Exoskeleton Technology
• Control Systems Engineering

Background:

• Existing exoskeleton teleoperation systems face challenges with arm length adjustment, dynamic control, and precision.
• High-risk operations like deep-sea exploration and nuclear maintenance require advanced remote control solutions for personnel safety.

Purpose of the Study:

• To develop and validate a reproducible unilateral upper limb exoskeleton teleoperation system with enhanced kinematic matching and control.
• To address limitations in adaptability, accuracy, and dynamic response found in current teleoperation technologies.

Main Methods:

• A 7-DOF active drive exoskeleton architecture was designed, incorporating low-inertia joints, ergonomic alignment, passive scapulothoracic compensation, and digital adaptive arm length adjustment.
• A hybrid control strategy combining master-end position impedance control with slave-end force-based impedance feedback was implemented, utilizing Lagrange equations and adaptive weighted coefficients.
• System stability was verified using Lyapunov functions and the LaSalle invariance principle, with experiments conducted on a Franka Panda robot within a Linux real-time kernel and ROS architecture.

Main Results:

• The system demonstrated high-precision master-slave synchronization, accurately reproducing spatial trajectories with effective gravity compensation.
• Ablation experiments revealed significant reductions in peak contact force (68.8%) and minimal deviation in arm length measurement after multiple uses.
• The exoskeleton system successfully overcame adaptability and robustness deficiencies, achieving precise load compensation.

Conclusions:

• The developed unilateral upper limb exoskeleton teleoperation system offers superior adaptability, robustness, and precision for high-risk scenarios.
• The system's capabilities extend to potential applications in rehabilitation training for hemiplegic patients.
• This research advances teleoperation technology, providing a reliable solution for remote manipulation and human-robot interaction.