Area Light Effect Method for Illumination Calculation in BLM
Since its introduction, BIM technology has become a research hotspot in the electrical design industry with its advantages of three-dimensional design, collaborative design, building electrical energy consumption analysis and pipeline collision inspection; especially the emergence of Autodesk Revit software has integrated the building electrical Lighting design is pushed to a new level. Compared with traditional two-dimensional and three-dimensional software, BIM has the advantages of ensuring the complete transmission of information among various disciplines, collision inspection, refined design, and visualization[2]. The British Cabinet Office released the "Government Construction Strategy" as early as May 2011, stipulating that by 2016, all public construction projects must meet the BIM secondary standard; my country has also promulgated national standards related to BIM, including "China BIM Standard System CBIMS Frame>Close. Calculation of illuminance is the key to the entire lighting design. When calculating, the calculated illuminance value and power density value should be considered to meet the design requirements, aiming to provide users with a good living environment.
Get the spatial illuminance analysis table through Autodesk Revit, and use the known average estimated illuminance to get the illuminance difference of the required lighting level. Further verify whether the power density value of the room meets the requirements, which greatly improves the design efficiency, but the estimated illuminance value is quite different from the actual illuminance value.
The literature proposes the area light effect method to calculate the indoor illuminance value, but this paper simply proposes this calculation method without further elaborating its use value. In literature [10], aiming at the disadvantages of the utilization coefficient method, such as single type of calculation structure, that is, it can only calculate the illuminance value of a regular-shaped room, difficult table look-up, cumbersome calculation, etc., a illuminance calculation method based on fuzzy utilization coefficient is proposed. This algorithm solves the problem of using It is difficult to look up the coefficient table and the calculation is cumbersome, but the illuminance value calculated by using the fuzzy utilization coefficient method is very different from the actual value.
In the literature, a simplified calculation method is proposed in the case that the conventional coefficient method is used to calculate the illuminance value and the lighting power density value are cumbersome. Two new physical quantities are introduced, effective luminous flux and fuzzy coefficient, which are composed of luminous flux, utilization coefficient, maintenance coefficient and light efficiency, utilization coefficient, maintenance coefficient respectively. In the design process, the illuminance value and power density value are calculated by querying the effective luminous flux and fuzzy coefficient in the simplified calculation table. Although the algorithm process is quick and easy to calculate, it is necessary to obtain the required utilization coefficient value by looking up the table.
The literature proposes the illuminance calculation based on MATLAB's RBF neural network, compared to other illuminance calculation methods. To a certain extent, the amount of manual calculation is reduced, but the disadvantage is that training requires a large number of samples and the number of samples is calculated by using the coefficient method. Calculations are inaccurate. Documents [13-141 use DIALux lighting software to simulate and calculate the building illuminance value. The results show that the illuminance value is close to the actual value. Therefore, for the situation where the building illuminance value is difficult to measure, the building illuminance value can be measured by using the DIALux lighting software. The illuminance value is simulated and calculated; however, the software algorithm is closed and cannot be used by users. None of the above methods can improve the design efficiency under the conditions of strong adaptability to illuminance calculation, no need for a large number of look-up tables, and high calculation accuracy.
