Research On Indoor LED Glare Based On Visual Comfort

The problem of visual comfort of lighting emitting diode(LED)has gradually attracted people's attention in indoor lighting application,because of its small size,high brightness and adjustable light color.Based on the high dyilamic range image luminance test method,this thesis designs and develops the R/G/B/W LED sources modules,and its glare effect is systematically studied by subjective and objective analysis methods.Main tasks as follows:Firstly,based on the photographic characteristics and imaging principle of digital cameras,a calculation method to obtain luminance parameters is investigated according to the high dynamic range(HDR)image technology.The method combines a set of low dynamic range time series images into HDR images using Photosphere software.The gray value of the image is calculated and fitted with the tristimulus value RGB data obtained by linear transformation.The model of the luminance is obtained and the luminance of each color block of the standard color plate is calculated under three background luminance.The research results show that the average luminance error of each color block of the standard plate calculated in three background luminance is less than 9.22%,the luminance errors of all color block targets and the color targets are reduced with the decrease of background luminance,and the luminance error of the gray targets reaches minimum when the background luminance is in an appropriate scope.Secondly,based on the study of the effects of indoor LED discomfort glare,the R/G/B/W four color LED sources modules were designed and developed.The photoelectric performance of the modules was tested.The applicability of the HDR images luminance measurement method is verified to the module.The research results show that the calculated average error of luminance of W-LED source is 3.892%.The glare effect of R/G/B/V LED sources modules was studied in three different background luminance,and subjective and objective evaluation tests were carried out under each condition.The results show that the glare effect of the R/G/B/W LED sources is different in the three different background luminance;Larger the luminance of the four different spectral power distribution LED modules in the same background luminance lead to higher subjective rating score,namely more discomfort glare;The largest glare is caused by the B-LED and the smallest glare is caused by the W-LED in the four LED modules.Finally,based on the above research results,the glare evaluation models for R/G/B/W LED sources modules were established.The applicability of the model is verified by studying the glare effect of W-LED light source module based on HDR image in three background luminance.The experimental results show that the correlation coefficient between the WUGRmoaifsed value calculated by the model and the subjective score of the subject is R2=0.960,0.981,0.978 in three background luminance.The models were compared with UGR,mUGRspd and QUGRSPD model.The results show that the models have certain applicability,and the models are simpler than other models because of its fewer parameters.