A study on wrist-based haptic weight conveyance in immersive virtual environments

Abstract: Physical properties of objects are some of the features that are lost when users are immersed in today's virtual environments that usually only provide visual and auditory stimuli. In a quest to recover the physical perception of touch, in this work, we present two different studies to assess how force feedback applied solely on the wrist can convey weight. This localized approach is implemented with a wearable device, which is an advantage regarding mobility. Part of our motivation comes from balance tasks that involve interaction with objects, where there is a need to perceive their weight.We first propose an experiment to assess how we can use the force feedback on the wrist to alter the weight perception when manipulating physical props in VR.Then, we implement and evaluate two experiments in several days setting with a single participant, using only virtual representations of the objects. In the first experiment, we propose a task involving ordering objects, from the lightest to the heaviest. The second experiment also assesses weight perception, but at this time, asking the participants to compare only two objects grabbed at distinct points. In both procedures, the tasks are repeated hundreds of times to remove any bias that can come from memorizing the orders and combinations presented. From these studies, we found that the force stimuli localized on the wrist are sufficient to convey weight information. We also found that grabbing the objects at different points affects the perceived weight to a certain extent due to how the two motion axes of the wrist are placed. The behavior we observed in weight discrimination, and its limitations are equivalent to the ones found in previous studies performed using real weights.Besides these studies, an additional contribution of this work is an effective experimental design relying on a single participant in a long term setting.