Acoustic-based passive pointing system for distant screens

This paper presents a passive pointing system for a distant screen based on an acoustic position estimation technology in conjunction with a gravity sensor on a smartphone. The system is designed to interact with a distant large screen such as a television set at home or digital signage in public. The system consists of a screen, two loudspeakers set around the screen, and a smartphone as a pointing device having a microphone and a gravity sensor inside. The position of the pointer is theoretically determined by the position and direction. This smartphone-based system approximates the position and direction by the two-dimensional position of the microphone horizontally and the pitch angle from the gravity sensor vertically. In this paper, we report experiments to evaluate the performance of the system. The loudspeakers of the system radiate burst signal from 18 to 24 kHz. The position of the smartphone is estimated at a frame rate of 15 Hz with a latency of 0.4 second. The accuracy of the pointer was measured as an angle error below 10 degrees for 100% of all frames. We confirmed that it has enough accuracy to point to each region which is divided area in the screen for applications such as quiz or questionnaire on digital signage.