Two-point haptic pattern recognition with the inverse filter method

Abstract

Touchscreens are widely used nowadays, yet still crucially lack haptic feedback for a rich interaction. Haptic feedback presents several benefits for touch interactions but can be difficult to achieve on a surface, due to issues of vibration propagation. The Inverse Filter Method enables to achieve localised multitouch haptic feedback on a glass surface by controlling the vibrations field over the entire surface. This recent method could enable a wide range of novel interactions. Yet, it has not been tested with users. This paper presents an initial study evaluating 2-point based pattern recognition using IFM with two fingers from each hand and with different timing difference in presentation, varying from 0 ms to 300 ms. The results are promising as participants could discriminate rather well the different patterns with averaged rates of 83% for simultaneous stimuli and up to 92% for stimuli separated by 300 ms.