Evaluation Method And Experimental Research Of Light Environment Based On EEG

From green buildings to healthy buildings,the creation of indoor environment comfort has attracted more and more attention.At first,artificial environmental science only took thermal and humid environment and air quality as the main research objects to create a thermally comfortable environment.In recent years,environmental factors such as light environment and acoustic environment that are easily neglected have received more and more attention.Regrettably,most of the existing researches are based on the subjective evaluation of environmental satisfaction and comfort from the perspective of environmental changes,that is,from the perspective of working conditions or scene settings.Moreover,the relevant standards only stipulate the items that must be controlled and the items used for scoring from the aspect of building performance,and do not use the objective physiological indicators of the building users as the evaluation criteria.The light environment is an indispensable part of the built environment,but there is currently a lack of relevant research on the objective evaluation methods of the light environment.This paper selects EEG as the objective physiological indicator of light environment evaluation,separately elaborates the theoretical basis of EEG and evoked potential,theoretically analyzes the feasibility,advantages and disadvantages,and applicable scenarios of the two for light environment evaluation.On this basis,the preprocessing methods,analysis methods and statistical methods of EEG signals are introduced.On the theoretical basis,for the evoked potential part,the black and white checkerboard pattern flip stimulus is used to test the visual evoked potential under different illuminances.Using wavelet transform and energy analysis methods,the definition of the energy coefficient is given,and the energy coefficient is compared with the light environment variable.Significance analysis was performed to verify that the illuminance changes did cause the intensity of the visual evoked potential oscillations,and explained the relationship between PRVEP energy and biological energy consumption from a neurophysiological point of view.Finally,gave a satisfactory range of illuminance to the subjects and the energy coefficient range.For the EEG part,mainly by recording EEG data over a period of time and extracting the power of the four bands,the relationship between the power ratio of the four bands and the illuminance is analyzed.After the saliency analysis with the illuminance one by one,the most significant is selected.The logarithmic power of the β-band is used as the characteristic value,combined with subjective evaluation,gives the illuminance range that satisfies the subject and the average logarithmic power range of the β-band.Regardless of EEG or evoked potential,the core idea of this study is to find the characteristic values of EEG signals that are significantly related to the light environment variables,combined with the subject’s subjective evaluation of the light environment,and give the subject’s response to the light environment.The satisfactory range of light environment variables,or a certain characteristic value to express a certain subjective feeling,provides ideas and methods for reference in future research.