Virtual Reality (VR) sickness is common with symptoms such as headaches, nausea, and disorientation, and is a major barrier to using VR. We propose WalkingVibe, which applies unobtrusive vibrotactile feedback for VR walking experiences, and also reduces VR sickness and discomfort while improving realism. Feedback is delivered through two small vibration motors behind the ears at a frequency that strikes a balance in inducing vestibular response while minimizing annoyance. We conducted a 240-person study to explore how visual, audio, and various tactile feedback designs affect the locomotion experience of users walking passively in VR while seated statically in reality. Results showed timing and location for tactile feedback have significant effects on VR sickness and realism. With WalkingVibe, 2-sided step-synchronized design significantly reduces VR sickness and discomfort while significantly improving realism. Furthermore, its unobtrusiveness and ease of integration make WalkingVibe a practical approach for improving VR experiences with new and existing VR headsets.

We present HeadBlaster, a novel wearable technology that creates motion perception by applying ungrounded force to the head to stimulate the vestibular and proprioception sensory systems. Compared to motion platforms that tilt the body, HeadBlaster more closely approximates how lateral inertial and centrifugal forces are felt during real motion to provide more persistent motion perception. In addition, because HeadBlaster only actuates the head rather than the entire body, it eliminates the mechanical motion platforms that users must be constrained to, which improves user mobility and enables room-scale VR experiences. We designed a wearable HeadBlaster system with 6 air nozzles integrated into a VR headset, using compressed air jets to provide persistent, lateral propulsion forces. By controlling multiple air jets, it is able to create the perception of lateral acceleration in 360 degrees. We conducted a series of perception and human-factor studies to quantify the head movement, the persistence of perceived acceleration, and the minimal level of detectable forces. We then explored the user experience of HeadBlaster through two VR applications: a custom surfing game, and a commercial driving simulator together with a commercial motion platform. Study results showed that HeadBlaster provided significantly longer perceived duration of acceleration than motion platforms. It also significantly improved realism and immersion, and was preferred by users compared to using VR alone. In addition, it can be used in conjunction with motion platforms to further augment the user experience.

Virtual Reality (VR) sickness occurs when exposure to a virtual environment causes symptoms that are similar to motion sickness, and has been one of the major user experience barriers of VR. To reduce VR sickness, prior work has explored dynamic field-of-view modification and galvanic vestibular stimulation (GVS) that recou-ples the visual and vestibular systems. We propose a new approach to reduce VR sickness, called PhantomLegs, that applies alternating haptic cues that are synchronized to users' footsteps in VR. Our prototype consists of two servos with padded swing arms, one set on each side of the head, that lightly taps the head as users walk in VR. We conducted a three-session, multi-day user study with 30 participants to evaluate its effects as users navigate through a VR environment while physically being seated. Results show that our approach significantly reduces VR sickness during the initial exposure while remaining comfortable to users.