Comparing Physical Human-Robot Interaction with Spring-and Elastomer-Based Series Elastic Actuators

Area of Science:

• Robotics
• Biomechanics
• Human-Robot Interaction

Background:

• Physical human-robot interaction (pHRI) is critical for rehabilitation exoskeleton design.
• Series Elastic Actuators (SEAs) enhance comfort and compliance in exoskeletons.
• Elastomers are a novel alternative to traditional springs in SEAs, but their human perception is understudied.

Purpose of the Study:

• To quantitatively and qualitatively compare human perception of elastomers versus springs in SEAs.
• To assess comfort and motion smoothness during interaction with different compliant elements.
• To inform the design of future SEAs for improved pHRI in exoskeletons.

Main Methods:

• Designed two mechanisms to compare spring and elastomer compliant elements.
• Employed a cross-over experimental design to mitigate learning effects.
• Collected quantitative and qualitative data on human interaction and perception.

Main Results:

• The elastomer was perceived as slightly more comfortable than the spring.
• Motion smoothness was rated as slightly better with the elastomer compared to the spring.
• Both quantitative and qualitative data supported the advantages of elastomers.

Conclusions:

• Elastomers show promise as a compliant element in SEAs for enhancing pHRI.
• The findings suggest elastomers can improve comfort and motion smoothness in rehabilitation exoskeletons.
• Further research into elastomer-based SEAs is warranted for advanced exoskeleton design.