High Performance Tethered Knee Exoskeleton

Datasheet

Benefits/Advantages

Property Value
Lightweight Unilateral exoskeleton weight only 1 kg
High Torque Density Motor 7.0 Nm/kg, 4 times for other available devices
Effective Assistance Nominal torque is 48 or 64 Nm, can provide more than 50% torque assist for walking and reduce 75% muscle activities for squatting
High Bandwidth 65 Hz, walking and running are super stable
High Backdrivability 0.9 Nm, almost no mechanical resistance is felt
High Stiffness 15 ms
Interface Type >350 Nm/rad, more than average stiffness value of normal walking 260 Nm/rad
High Accuracy Tracking error < 3%

Tethered Exoskeleton Architecture

Video

Publication

Yu S, Huang TH, Wang D, Lynn B, Sayd D, Silivanov V, Park YS, Tian Y, Su H. Design and Control of a High-Torque and Highly-Backdrivable Hybrid Soft Exoskeleton for Knee Injury Prevention during Squatting . IEEE Robotics and Automation Letters (RA-L), 2019. PDF | Video

Comparison

Tethered System

  • Wearable structure weight: 1 kg
  • Transmission: 24:1 gear, bi-directional actuation
  • Torque output: >50 Nm torque, >6.5 rad/s speed
  • Control platform: MATLAB Simulink Realtime

    • Portable System

  • Total weight: 2.5 kg (unilateral), 3.9 kg (bilateral)
  • Transmission: 6:1 gear, bi-directional actuation
  • Torque output: 20 Nm torque, >26 rad/s speed
  • Control platform: Arduino Teensy 3.6 microcontroller