ViESTac: A Multimodal VR Evaluation Suite for Novel Tactile Devices

Abstract

Virtual Reality (VR) applications designed for the purpose of testing or evaluating tactile devices are strongly predisposed to the respective device display capabilities, and are developed across multiple software platforms. This thesis presents "ViESTac", a multimodal VR evaluation suite for evaluating and comparing novel tactile devices. To account for the wide variety of existing devices and their tactile capabilities and idiosyncrasies, an extensive literature review was conducted to determine the requirements for such a suite. ViESTac contains two virtual environments, one for simulating different tactile properties of virtual objects like stiffness, macro-roughness, fine-roughness, temperature, friction, and the other for supporting positioning accuracy in standard tasks in VR or teleoperation (such as pickand-place, peg-in-hole, etc). ViESTac also allows easy integration of tactile devices, and can support popular, unobtrusive hand tracking systems such as the Leap Motion controller. The potentiality of this VR suite has been exemplified through an evaluation study involving two tactile devices - FingerTac and FerroVibe - and thirteen participants. Tasks on discriminating contact point orientation, texture, stiffness were carried out in addition to object positioning. Results showed that participants could almost immaculately distinguish between the different conditions tested for the tactile properties, with little variance. Tactile guidance for positioning tasks was found to be moderately helpful as compared to the complexity of the tasks. Furthermore, both devices were compared on grounds of trajectory lengths, completion times and overall helpfulness. Collectively, these served as a testament to the working of ViESTac.