JetController: High-speed Ungrounded 3-DoF Force Feedback Controllers using Air Propulsion Jets

Title of the Paper

JetController: High-speed Ungrounded 3-DoF Force Feedback Controllers using Air Propulsion Jets

Paper Information

• Subject Area: Virtual Reality (VR), Force Feedback Technology, Ungrounded 3-DoF Force Feedback Devices
• Keywords: High-speed haptic feedback, air propulsion, ungrounded force feedback, virtual reality, 3 degrees of freedom

Research Background and Problems

• Identified Issues or Challenges:

  • Traditional vibration motors and linear resonant actuators (LRA) are limited to vibration directionality and cannot generate sustained force feedback.
  • Existing ungrounded force feedback devices based on propellers operate at slow speeds, with a maximum impact frequency of only 2Hz, unable to support fast-paced VR game events.
  • Grounded force feedback devices are restricted in application scope, while ungrounded devices generally fail to achieve high degrees of freedom and sustained force feedback.

• Significance:

  • High-quality haptic feedback can significantly enhance immersion and interaction realism in virtual reality and video games.
  • Actions such as automatic weapon simulation or high-speed cutting in VR games require devices to support high-frequency haptic impacts while maintaining a compact and lightweight structure to improve user experience.

• Research Motivation and Related Work:

  • Compared to previous air propulsion-based devices, JetController offers higher frequencies, stronger impact forces, and a more lightweight design.
  • The study explores the performance requirements of haptic feedback devices in relation to human button-pressing speeds and fast-paced game events.

Solution

• Proposed Method:

  • JetController: A device utilizing air propulsion technology to achieve ungrounded 3 degrees of freedom (3-DoF) force feedback.
  • High-speed pneumatic solenoids regulate compressed air to generate impact frequencies ranging from 20Hz (4.0N) to 50Hz (1.0N).

• Innovations:

  • First implementation of a high-speed (>20Hz) ungrounded 3-DoF force feedback device, supporting human button-pressing speeds and high-frequency automatic weapon events.
  • Lightweight system design, with the handheld component weighing only 158g, making it more portable compared to existing propeller-based devices.
  • Optimized noise control and air propulsion performance, significantly reducing noise while improving response speed.

• Implementation Steps and Key Technologies:

  • A composite force feedback system composed of five directional air nozzles.
  • Adjustment of nozzle positions to prevent airflows from interfering with the user.
  • Integration of a high-pressure air tank for mobile use and a backpack-style air compressor to extend usage scenarios.
  • High-speed solenoid valve control achieved through Arduino Nano and MOSFET transistors to generate haptic impacts.
  • Open-source design files (hardware models and C# control software) provided for researchers.

Research Outcomes

• Specific Results:

  • JetController achieved impact frequencies of 20Hz (4.0N) and 50Hz (1.0N), significantly outperforming existing technologies (<5Hz).
  • Integrated into popular VR games Beat Saber and Half-Life: Alyx, demonstrating support for complex 3-DoF interactions.

• Advantages:

  • The haptic feedback realism and immersion provided are significantly superior to commercial vibration controllers.
  • The lightweight design of the system makes it more suitable for prolonged use (handheld weight is only 23% of Thor’s Hammer).
  • Wireless options enhance user mobility, making it suitable for more gaming scenarios.

• Experimental or Evaluation Results:

  • User experience experiments showed that JetController significantly outperformed vibration controllers in directional recognition, realism, enjoyment, and overall experience.
  • In Beat Saber, 83.3% of participants preferred JetController; in Half-Life: Alyx, this proportion reached 91.7%.

• Limitations and Future Directions:

  • Noise may disturb others and requires further optimization or integration as part of the haptic experience.
  • Currently supports only 3-DoF force feedback; future plans include exploring rotational force feedback to achieve 6-DoF functionality.
  • The weight of the mobile version still has room for optimization, potentially using lighter pressure regulators and solenoids.
  • Multi-handle interactions may cause airflow interference with the user's body; dynamic nozzle adjustment techniques could be explored.

Conclusion

JetController delivers industry-leading ungrounded 3-DoF force feedback technology and excels in VR game user experience evaluations. The study also open-sourced the technical design, aiming to advance haptic interaction technologies and bring more possibilities to game and virtual reality interaction design.