|dc.description.abstract||With the rapid development of LED lighting technology, how to effectively manage the lighting systems has become an important topic. Intelligent lighting can be a combination of management and monitoring features that adjusts the output of luminaires spatially or temporally, in order to provide lighting environments with energy efficiency and users’ well-being.
This study focuses on the lighting of a work environment with a computer monitor under an intelligent desk lamp. The lamp has the capability to control the central and outer luminous parts independently. Since the monitor also shines light to the user, we assume dimming the central luminous part would provide better illumination. By adjusting the correlated color temperature (CCT) and central illuminance, psycho- physical experiments are carried out to explore the impact of these two factors on visual comfort, visual fatigue and task performance. Luminaire control models are then established based on the experimental results.
The statistical analyses of the experimental data show that both the CCT and illuminance are not significant factors for the typing speed, typo-finding accuracy and CFF difference, and there is no interaction between the two independent variables. In the subjective assessments, only the brightness and glare perceptions are significantly influenced by the CCT and illuminance, and the other aspects evaluated in the questionnaire are not. The results show that changing the illuminance and CCT will affect the brightness perceptions in all the considered areas, including the central, left, and front reading areas.
To predict the brightness perception of the desk lamp under other operating conditions, the experimental data are used to model the brightness ratings as functions of CCT and illuminance. The R2 measures of goodness of fit are 0.9436, 0.9521 and 0.9476 for the central, left and front areas, respectively. All three R2 values are above 0.7, indicating that the models can well predict the brightness ratings. A weighted control model for the intelligent luminaire is then constructed by using the fitted models in all three areas. The region where the brightness rating is within 5 points plus or minus one standard error of the model is defined as the operating range for proper brightness. To account for user variations, the centroid of this region is our suggested operating point.||en_US|