Perceptual Dimensions of Physical Properties of Handheld Objects Induced by Impedance Changes

Haptics in virtual reality is the emerging dimension after audiovisual experiences. Researchers designed several handheld VR controllers to simulate haptic experiences in virtual reality environments. Some of these devices, equipped to deliver active force, can dynamically alter the timing and intensity of force feedback, potentially offering a wide array of haptic sensations. Past research primarily used a single index to evaluate how users perceive physical property parameters, potentially limiting the assessment to the designer's intended scope and neglecting other potential perceptual experiences. Therefore, this study evaluates not how much but how humans feel a physical property when stimuli are changed. We conducted interviews to investigate how people feel when a haptic device changes motion impedance. We used thematic analysis to abstract the results of the interviews and gain an understanding of how humans attribute force feedback to a phenomenon. We also generated a vocabulary from the themes obtained from the interviews and asked users to evaluate force feedback using the semantic difference method. A factor analysis was used to investigate how changing the basic elements of motion, such as inertia, viscosity, and stiffness of the motion system, affects haptic perception. As a result, we obtained four critical factors: size, viscosity, weight, and flexibility factor, and clarified the correspondence between these factors and the change of impedance.