Experimental evaluation for occupancy lighting control using combination of PIR and image-based sensors

Abstract

Recently, the effectiveness of image-based sensors, which are based on image-processing techniques, has been analysed in terms of occupancy lighting control in comparison with a passive infrared (PIR) sensor, which monitors changes in infrared radiation from moving occupants. However, the image-based sensor has two shortcomings: occupants cannot be accurately detected in a dark environment, and the overall energy consumption from the light and sensor is excessive. Therefore, we evaluated a combined approach that employs both the PIR sensor and the image-based sensor simultaneously. Because the combined sensor uses the image-based sensor only in a sufficiently bright environment, the first shortcoming can be overcome. In addition, an experiment, was conducted at a single office, demonstrating that the combined sensor's overall energy consumption decreased by 3.59% or more compared with either of its constituent sensors individually. Thus, the combined sensor resolves the major shortcomings of the image-based sensor's performance. Further discussion and careful analysis are included in this paper.