Passive Pointing System for Distant Screens Using Acoustic Position Estimator and Gravity Sensor

Abstract

This paper presents two passive pointing systems for a distant screen based on an acoustic position estimation technology. These systems are designed to interact with a distant screen such as a television set at home or digital signage in public as an alternative to a touch screen. The first system consists of a distant screen, three loudspeakers set around the screen, and two microphones as a pointing device. The second system consists of a distant screen, two loudspeakers set around the screen, and a smartphone equipping a microphone and a gravity sensor inside as a pointing device. The position of the pointer on the screen is theoretically determined by the position and direction of the pointing device in the space. The second 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 these systems. The loudspeakers of these systems radiate burst signal from 18 to 24kHz. The position of the microphone is estimated at a frame rate of 15 frames per second with a latency of 0.4s. 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 one of several partitioned areas in the screen.