Design and Analysis of Non-dynamic Hip Joint Assisted Exoskeletons

Abstract

To improve the human-machine coordination of existing assistive exoskeletons, this study utilizes experimental data collection of human lower limb motion to establish inverse kinematic and inverse dynamic models. Analysis is conducted on parameters such as angles, torques, and kinetic energy of the hip joint during walking. Based on these parameters, a variable stiffness spring-based energy storage element is proposed and designed for the passive hip joint assistive exoskeleton. Human-machine coupling simulations are carried out using Adams software to validate the designed exoskeleton's coordination with human movements. The simulation results indicate that the designed passive hip joint assistive exoskeleton demonstrates favorable human-machine coordination. Subsequently, the physical prototype of the exoskeleton is fabricated, and a wearable experiment is conducted. The experimental results show an average reduction of 5.6% in hip joint torque and 6.25% in work done during the gait cycle with the exoskeleton. This confirms the positive assistance effect of the passive hip joint assistive exoskeleton on the human walking.

Keywords

• Hip joint assisted exoskeleton
• Variable stiffness spring
• Inverse kinematic
• Inverse dynamic
• Simulation