What does it mean to cycle in Virtual Reality? Exploring Cycling Fidelity and Control of VR Bicycle Simulators

Title of the Paper

What does it mean to cycle in Virtual Reality? Exploring Cycling Fidelity and Control of VR Bicycle Simulators

Paper Information

• Field of Study: Design and evaluation of cycling simulators in virtual reality
• Keywords: Virtual reality, cycling, mobility, bicycle simulator, control, simulation fidelity

Research Background and Problem

• Problems or challenges identified by the authors:

  • Current virtual reality (VR) bicycle simulators often use fixed-platform designs, which lack a complete cycling experience, including balance, coordination, and physical movement through space.
  • VR head-mounted devices occupy the cyclist's visual channel, making it unclear how much external realism is required and the degree of precision needed for bicycle control.
  • Creating highly realistic VR cycling experiences is often costly and time-consuming, but it is unclear whether this level of realism is always necessary.

• Importance:

  • Bicycle simulators play a significant role in entertainment, health, and research evaluation. Enhancing their realism and safety can provide users with a more immersive virtual cycling experience while reducing the impact of VR-related sickness (e.g., motion sickness).

• Research motivation and related work:

  • The authors reviewed related studies and found that while software fidelity has limited impact on the cycling experience, hardware fidelity is critical to user experience outcomes.
  • Previous research has focused on reducing VR motion sickness and enhancing immersion but lacks systematic exploration of how hardware fidelity affects cycling safety, realism, and motion sickness.

Solution

• Methods or solutions proposed by the authors:

  • Design and evaluate three types of VR cycling simulators:
    1. Bikeless: No physical bicycle is used, only handlebars and pedals.
    2. Stationary: A bicycle mounted on a fixed platform.
    3. Tandem: A mobile tandem bicycle that enables spatial movement for a more realistic cycling experience.
  • Investigate four levels of control (no control, steering only, pedaling only, steering + pedaling) and analyze their impact on cycling realism and safety.

• Innovations:

  • Propose a tandem bicycle-based simulator design to achieve a more realistic VR cycling experience while exploring whether a physical bicycle is necessary for simulation.
  • Use experimental design to systematically compare the effects of hardware and control dimensions on virtual cycling, including evaluations of safety, realism, and motion sickness.

• Implementation steps and key technologies:

  • Develop a virtual environment using Unity, integrated with VR devices (Oculus Quest) and sensors (Arduino board and pedal sensors).
  • Set up experimental equipment and conduct experiments with 24 participants in both indoor and outdoor scenarios.
  • Collect data on movement metrics, head rotation, and subjective questionnaire feedback, including motion sickness, realism, and safety.

Research Findings

• Specific findings:

  • Experimental results show:
    • The Bikeless setup provides the highest sense of safety but has lower realism.
    • The Tandem setup delivers the highest cycling realism without significantly increasing motion sickness.
    • The steering + pedaling control combination significantly enhances users' sense of control over the virtual cycling experience.

• Advantages over existing solutions:

  • The proposed tandem bicycle setup provides a more realistic cycling experience, which fixed-platform simulators cannot achieve.
  • Regarding the necessity of a physical bicycle, experimental data indicate that a bicycle is not essential in virtual environments, supporting the design of lower-cost indoor simulators.

• Experimental or evaluation results:

  • All setups exhibited low VR motion sickness scores (SSQ), and the Tandem setup achieved the highest IPQ (Presence Questionnaire) scores.
  • In participants' subjective rankings, Tandem was considered the most realistic, while Bikeless was deemed the safest.

• Limitations and future directions:

  • Limitations:
    • Complex scenarios such as downhill routes and multi-turn paths were not explored.
    • The safety of the Tandem setup still requires optimization, such as improving braking mechanisms.
    • Only fixed steering handlebars were used, without investigating natural steering methods based on body tilts.
  • Future directions:
    • Study control requirements for virtual cycling in complex routes.
    • Explore the introduction of environmental factors such as wind speed and noise in indoor setups to enhance realism.
    • Develop more versatile VR mobile simulators that support other micro-mobility modes, such as electric scooters.