Occupancy distribution estimation for smart light delivery with perturbation-modulated light sensing

Abstract

The advent of modern light-emitting diode (LED) techniques enables us to develop novel lighting systems with numerous previously unavailable features. Specifically, by using the fixtures for both illumination and to interrogate the space, source-to-sensor communication becomes possible at very low cost. In this paper, we present a novel framework to estimate the occupancy distribution in an indoor space using color-controllable LED fixtures (the same fixtures providing the illumination, simultaneously) and sparsely distributed non-imaging color sensors. By modulating randomly generated perturbation patterns onto the drive signals of the LED fixtures and measuring the changes in the color sensor responses, we are able to recover a light transport model for the room. Two approaches are proposed to estimate the spatial distribution of the occupancy, based on a light blockage model and a light reflection model, respectively. These two approaches, which can be combined, can faithfully reveal the occupancy scenario of the indoor space, while preserving the privacy of its occupants. An occupancy-sensitive lighting system can be designed based on this technique.