PropelWalker: A Leg-Based Wearable System With Propeller-Based Force Feedback for Walking in Fluids in VR

Area of Science:

• Virtual Reality (VR)
• Haptic Feedback
• Human-Computer Interaction

Background:

• Simulating real-world walking in virtual reality (VR) across diverse fluid mediums remains a significant challenge.
• Existing haptic interfaces struggle to accurately replicate the complex forces encountered when interacting with different materials.

Purpose of the Study:

• To introduce PropelWalker, a pair of calf-worn haptic devices designed to simulate buoyancy and resistant forces in VR.
• To evaluate the technical performance and user perception of the PropelWalker system for realistic haptic feedback.

Main Methods:

• PropelWalker utilizes four ducted fans (two per calf) to control airflow strength and direction in real-time.
• Technical evaluations measured force generation capabilities (up to 27N, 0.85s response time) and force stability.
• Three user perception studies assessed just-noticeable-difference (JND) for airflow force, distinguishability of simulated mediums, and impact on VR presence.

Main Results:

• PropelWalker can generate vertical forces up to 27N in both upward and downward directions within 0.85 seconds.
• The system demonstrated stable force maintenance with minimal turbulence.
• Users could distinguish four simulated walking mediums (dry ground, water, mud, sand) with 94.2% accuracy and reported significantly improved VR presence.

Conclusions:

• PropelWalker effectively simulates the forces associated with walking in various fluid mediums in VR.
• The system enhances the sense of presence and immersion for users in virtual environments.
• This haptic device offers a promising solution for more realistic and engaging VR experiences.