Towards large scale smell display for enhancing immersion during walking in virtual environments

Incorporating olfactory stimuli into Virtual Reality (VR) has become a growing area of interest, offering new ways to enhance immersion and emotional engagement. However, current olfactory display solutions are often constrained by stationary emitters or wearable devices, which either restrict user mobility or cause discomfort. This thesis presents a novel approach to large-scale smell interaction in VR through a robot-mounted olfactory display that enables encounter-based scent delivery during natural walking. Built on a mobile Boston Dynamics Spot robot and an Olorama scent generator, the system autonomously navigates to predefined smell zones and synchronizes scent emission with user proximity, allowing for timed and spatially aligned olfactory cues without requiring users to wear additional hardware.The system was evaluated with a user study in a room-scale VR forest scenario with three distinct olfactory events, where the detection time, recognition accuracy, perceived intensity, and comfort of users during the interactions were assessed. Results show that users were generally able to detect and identify the smells correctly, with reaction times being influenced by differences in scent intensity. The results demonstrate that large-scale, robot-assisted scent delivery is not only technically feasible but also perceptually effective and well tolerated by users.By avoiding wearable gear, permanent installations, or room-specific infrastructure, the system offers a scalable and portable alternative for immersive olfactory interaction. It supports walk-based scenarios without confining users to a small area, enabling natural, spatially grounded scent delivery in various applications, including storytelling, therapy, or exhibitions. Overall, this work highlights the potential of mobile scent systems as a flexible and practical modality for enhancing immersion in VR.