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Experimental Evaluation of Reduction Technique for Time Delay of Turning Off Light to Occupancy Lighting Control

In this study, we clarify the effectiveness of the energy‐effective techniques for the occupancy lighting control that is based on an occupancy sensor. The time delay from detecting no occupant to turning off the light is used for performing the occupancy control to avoid erroneously turning off the light (hereafter referred to as false‐off). Our experiment was conducted at an actual home environment over 8 days. We evaluated the performance of an image‐based sensor, which detects the occupants using image‐processing techniques and time‐delay adaptation, which decreases the time delay without false‐off. Compared with a passive infrared sensor, the image‐based sensor increased the average sensing accuracy for occupants with small movements by 21.58% or more. In addition, compared with the no‐adaptation case, the time‐delay adaptation increased the rate of average lighting energy saving by 3.94% or more. However, the experimental results suggested that the parameter of the time‐delay adaptation should be carefully set in terms of the energy‐saving effect and false‐off. The analysis and its practical discussions are included in this paper to achieve further energy efficiency. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.