Design of a Multi-Joint Passive Exoskeleton for Vertical Jumping Using Optimal Control.

Area of Science:

• Biomechanics
• Robotics
• Human Augmentation

Background:

• Exoskeleton design and evaluation are time-consuming and costly.
• Simulations can accelerate exoskeleton development by modeling user-exoskeleton interactions.
• Existing simulations often focus on continuous movements, neglecting high-force, fast-motion tasks.

Purpose of the Study:

• To implement a passive exoskeleton-human interaction simulation for optimizing vertical jump height.
• To investigate the impact of various design parameters on jump performance.
• To identify optimal configurations for enhancing human explosive power.

Main Methods:

• Developed a planar human model with ankle, knee, and hip joints in OpenSim.
• Utilized Moco software for optimal control to determine muscle excitation for maximum jump height.
• Simulated passive exoskeleton interactions, varying spring stiffness, joint configurations, pulley types, and engagement angles.

Main Results:

• Jump height increased with spring stiffness up to an optimal point.
• Single-joint knee exoskeletons were more effective than hip or ankle.
• Multi-joint exoskeletons showed marginal improvement over single-knee designs.
• Elliptic pulleys offered advantages over round pulleys under tension limitations.
• Initial spring engagement angles up to 50 degrees did not reduce jump height.

Conclusions:

• Passive exoskeletons can effectively augment vertical jump height.
• Knee joint augmentation and multi-joint systems show significant potential.
• Design parameters like spring stiffness and pulley type influence performance.
• Simulation provides a valuable tool for optimizing exoskeleton designs for dynamic tasks.