2006 Fiscal Year Final Research Report Summary
Development of the Standard Daylight Source Model Based on the Cloud Property and Estimation of the Solar Energy by the Geostational Meteological Satellite Images.
Grant-in-Aid for Scientific Research (C)
|Allocation Type||Single-year Grants |
|Research Institution||Kyoto University |
UETANI Yoshiaki Kyoto University, Graduate School of Engineering, Associate Professor -> 京都大学, 工学研究科, 助教授 (00258302)
|Project Period (FY)
2005 – 2006
|Keywords||daylighting / energy saving / sky luminance / meteorological satellite / cloud amount / daylight control system / Video-Colorimetry / Sustainable Daylighting|
The purposes of the research are as follows :
1)To develop the daylight source model which expresses the fluctuations of weather, time, and season by the meteorologically measured atmospheric parameters.
2)To improve the accuracy of my own quasi-real time daylight model based on the geostationary meteorological satellite images.
3)To establish the "Sustainable Daylighting" which utilizes the natural light as much as possible, provides the comfortable luminous environment to the people, and reduce the CO2 emission.
In two years, the following research were conducted :
a)Automatic cloud amount measurement with 5 minutes intervals : A digital camera with a fisheye lens is colorimetrically calibrated by a spectro-colorimeter using my own Video-Colorimetry technique. The whole sky is captured as a circle sky image which is converted to the absolute values of distributions of luminance and correlated color temperature. The cloud amount is counted with the thresholds of luminance and correlated co
b)Estimation of the sky luminance distribution with 60 minutes intervals: The new sky luminance model is developed. The model is composed of optical scattaring, refraction and reflection processes of aerosol. The atmospheric parameters are decided by the geostationary meteorological satellite images.
c)Development of the daylight control system operating simultaneously with the sky luminance distribution : By measuring the sky luminance distribution using the another digital camera with a fisheye lens, the illuminance distribution in a room with windows are calculated. The minimum artificial lightings are dimmed to add the shortfall of the illuminance compared to the standard illuminance requirement. The experiment appealed the feasibility of the system. The simulation using annual measured data of sky luminance showed about 50% of electric power could be saved.
d) Combine of the sky luminance model by the satellite images and daylight control system above mentioned : Though 60 minutes intervals is longer than the digital camera, the geostationary meteorological satellite images cover the world. The initial and running costs are lower than light sensors. The simulations showed that ambient lightings are able to be controlled by the combine system. Less
Research Products (24 results)