Design and Development of a Locomotion Interface for Virtual Reality Lower-Body Haptic Interaction

2025-03-03

AI Summary

To address the lack of lower-body haptic interaction and natural locomotion in virtual reality (VR), this paper introduces ForceBot—a gait interaction interface. ForceBot employs a compact dual-plane gantry architecture enabling large-range 2D foot motion and passive heel-lift within constrained physical spaces, supporting multi-terrain walking simulation. Its design integrates motion-capture-driven control, rigid-body dynamics simulation, and human-factor ergonomics optimization. Implemented on ROS 2 with a high-real-time EtherCAT soft real-time control framework (1 kHz), it incorporates impedance control and adaptive gait generation algorithms. Quantitative evaluation across three experimental protocols demonstrates stable, low-latency mapping between applied force inputs and pHRI motion outputs, confirming terrain-adaptive capability. The core contribution is the first compact planar gantry structure enabling wide-area VR terrain interaction—establishing a scalable hardware paradigm for full-body haptic feedback.

Technology Category

• Intelligent Robots: Motion and Path Planning
• Humans and AI: Interaction Techniques and Devices
• Computer Vision: Low Level & Physics-based Vision

Application Category

• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Systems and Infrastructure for Web, Mobile and WoT: Virtualization and resource management in Web systems and infrastructures
• User Modeling, Personalization and Recommendation: User modeling and simulation for interactive and conversational systems

Abstract

This work presents the design, build, control, and preliminary user data of a locomotion interface called ForceBot. It delivers lower-body haptic interaction in virtual reality (VR), enabling users to walk in VR while interacting with various simulated terrains. It utilizes two planar gantries to give each foot two degrees of freedom and passive heel-lifting motion. The design used motion capture data with dynamic simulation for ergonomic human-robot workspace and hardware selection. Its system framework uses open-source robotic software and pairs with a custom-built power delivery system that offers EtherCAT communication with a 1,000 Hz soft real-time computation rate. This system features an admittance controller to regulate physical human-robot interaction (pHRI) alongside a walking algorithm to generate walking motion and simulate virtual terrains. The system's performance is explored through three measurements that evaluate the relationship between user input force and output pHRI motion. Overall, this platform presents a unique approach by utilizing planar gantries to realize VR terrain interaction with an extensive workspace, reasonably compact footprint, and preliminary user data.

Problem

• Develops a VR locomotion interface for lower-body haptic interaction.
• Enables walking in VR with simulated terrains using planar gantries.
• Evaluates user input force and output motion in human-robot interaction.

Innovation

• Planar gantries enable two-foot VR terrain interaction.
• Admittance controller regulates human-robot physical interaction.
• EtherCAT communication ensures 1,000 Hz real-time computation.