AtaTouch: Robust Finger Pinch Detection for a VR Controller Using RF Return Loss

Abstract

Handheld controllers are an essential part of VR systems. Modern sensing techniques enable them to track users' fnger movements to support natural interaction using hands. The sensing techniques, however, often fail to precisely determine whether two fngertips touch each other, which is important for the robust detection of a pinch gesture. To address this problem, we propose AtaTouch, which is a novel, robust sensing technique for detecting the closure of a fnger pinch. It utilizes a change in the coupled impedance of an antenna and human fngers when the thumb and fnger form a loop. We implemented a prototype controller in which AtaTouch detects the fnger pinch of the grabbing hand. A user test with the prototype showed a fnger-touch detection accuracy of 96.4%. Another user test with the scenarios of moving virtual blocks demonstrated low object-drop rate (2.75%) and false-pinch rate (4.40%). The results and feedback from the participants support the robustness and sensitivity of AtaTouch. the controllers to support natural interaction using gestures (e.g., Facebook's Oculus Touch [19], Valve Index Controller [10], and Tactual Labs [23]). Hand gestures such as a pinch gesture enable users to manipulate objects dexterously, grabbing and moving small virtual blocks, clicking a button, and controlling a slide bar [13]. Further, a simple thumb and fnger pinch interaction was reported to be useful in comfortable virtual text entry methods [4, 12].