Directional Force Feedback: Mechanical Force Concentration for Immersive Experience in Virtual Reality

In recent years, consumer-level virtual-reality (VR) devices and content have become widely available. Notably, establishing a sense of presence is a key objective of VR and an immersive interface with haptic feedback for VR applications has long been in development. Despite the state-of-the-art force feedback research being conducted, a study on directional feedback, based on force concentration, has not yet been reported. Therefore, we developed directional force feedback (DFF), a device that generates directional sensations for virtual-reality (VR) applications via mechanical force concentrations. DFF uses the rotation of motors to concentrate force and deliver directional sensations to the user. To achieve this, we developed a novel method of force concentration for directional sensation; by considering both rotational rebound and gravity, the optimum rotational motor speeds and rotation angles were identified. Additionally, we validated the impact of DFF in a virtual environment, showing that the users' presence and immersion within VR were higher with DFF than without. The result of the user studies demonstrated that the device significantly improves immersivity of virtual applications.