Localized Haptic Texture: A Rendering Technique Based on Taxels for High Density Tactile Feedback

We investigate the relevance of surface haptic rendering techniques for tactile devices. We focus on the two major existing techniques and show that they have complementary benefits. The first one, called Surface Haptic Object (SHO), which is based on finger position, is shown to be more suitable to render sparse textures; while the second one, called Surface Haptic Texture (SHT), which is based on finger velocity, is shown to be more suitable for dense textures and fast finger movements. We hence propose a new rendering technique, called Localized Haptic Texture (LHT), which is based on the concept of taxel considered as an elementary tactile information that is rendered on the screen. By using a grid of taxels to encode a texture, LHT is shown to provide a consistent tactile rendering across different velocities for high density textures, and is found to reduce user error rate by up to 77.68% compared to SHO.