Quantitative analysis of ambient lighting quality outside the commercial pedestrian street of Pingdingshan Institute of Technology Liu Gangsong (School of Architecture, Harbin Institute of Technology, Harbin 150001, China) The evaluation index and lighting design principles of ambient lighting quality outside the pedestrian street.
1 Visually oriented citizens in the behavioral activities of the pedestrian street, whether it is self-individual personal behavior or social behavior of commercial shopping and public interaction, both have the dual character of privacy and publicity. () Therefore, the commercial pedestrian street ambient lighting not only meets the mutual recognition of people before close contact, but also provides enough visual information to identify pedestrians within a certain distance on the pedestrian street.
CIE Publication No. 92, "City Lighting Guide" states: / In areas where the Pacers use dominance, the most important role of night lighting is to identify people who are approaching or at a certain distance. In order to give people the necessary sense of security, it must be possible to distinguish whether others may be friendly, abnormal or infringing in order to have sufficient time to respond appropriately. Studies have shown that the minimum recognition distance required to distinguish any signs of hostility and take precautionary measures is 4m in front of the observer. The semi-column illumination of the recommended commercial pedestrian street Esemicyl recommends not less than 0. 8lx, which is the face recognition distance (dface). Illuminance at approximately 4 m. The pedestrian street recommends Esemuyl to be around 31x. Esemicyl should be higher at the main entrances and exits, around the iconic buildings, and on the commercial roads, generally around 51x.
The above chromatic illumination values ​​are all illuminance at a height of 1.5 m on the ground, that is, the average height of an adult's face. In addition, vertical illuminance, average cylindrical illuminance, and average spherical illuminance can also be used as the basis for evaluating the illuminance level of face recognition. German lighting expert D. Fisher pointed out that the brightness of the human face should be 1cd/m2 and the vertical illumination is about 10x.
2 Modeling Stereoscopic CIE No. 92 publication states that / for the lighting of public spaces such as streets and squares, the characteristics of people's appearance, street furniture and buildings should be considered. "Vertical illumination Evert and semi-column The ratio of the surface illuminance Esemicyl is a good indicator for evaluating the stereoscopic feeling of the personal characteristic.
The pedestrian street is an informal social place. The stereoscopic induction of personal characteristics should be natural and soft. The contrast is not too strong, but it should not be too dull. The following shows three situations of the three-dimensional shape.
(a indicates dramatic, blunt effect, Evert/Esemicy: 0.2; b indicates the result of natural balance, Ev (rt/Esami (yl=1.25; c indicates monotonous dull effect, Evert/Esemicyl = stereoscopic three sense) When the situation is between <1.3, a better three-dimensional shape can be obtained. This is the limit of the three-dimensional sense index given in "Visual and Visual Environment": very glaring stereoscopic feeling when Evert/Es*nlcyl = 0; very The flat shape is three-dimensional Evert/Esn-l: 1*57, which basically matches.
3 Illumination distribution In order to ensure the quality of commercial street road lighting, the road lighting average level (illuminance) value, brightness (illuminance) uniformity, lighting maintenance coefficient and glare limit value should be determined. The CIE intensity is also required to meet the requirements of the semi-cylindrical illumination ESC (mln) value in urban road lighting. The results show that the height of the 1.5m face on the ground, in order to maintain good visibility, the ESC of 0.8m in 4m is 0.8Lx, and the lighting standard of the commercial street in the suburbs is 2.7Lx. 1 is shown.
Table 1 CIE lighting standard standard parameters city or town center district commercial street suburban commercial street road situation motor vehicle and pedestrian mixed road single 1 pedestrian road 4 light color and color rendering light source color quality including light indicating color and light source color rendering performance Two aspects.
The apparent color of light, the color table, can be described by color temperature or correlated color temperature. The choice of source color table depends on the atmosphere to be formed by the light environment. For example, a 'warm' light with a red component (low color temperature) is close to the twilight mood, which creates an intimate and relaxed atmosphere.
According to Cffi's suggestion, China's lighting design standards divide the color table of light source into three categories, as shown in Table 2. Table 2: Color table type of light source Type color table Related color temperature (K) I warm < 1~5cd/m2, 60~80 between the light and dark vision of the human eye. The color rendering performance of a light source with good color rendering for pedestrian street illumination depends on the spectral energy distribution of the light source. In addition to choosing a suitable light source to visualize the color, the ambient light outside the commercial pedestrian street should also pay attention to the influence of the light source on the color appearance of the pedestrians on the street (such as dress, skin color, etc.). For example, the mercury lamp lighting that has been used frequently in the past, people often feel that the color is gray and gray, as if it is ill, because the mercury lamp has poor color rendering for human skin color. In general, the brightness of the pedestrian street is about the middle, that is, the intermediate visual state.
Recommended commercial pedestrian street ambient lighting using the light source of the color Ra source is metal halide lamp, high color rendering high pressure sodium lamp (Ra > 60), QL electrodeless lamp, three primary color fluorescent lamp, incandescent lamp.
5 Brightness ratio For the illumination of the various elements of commercial pedestrian streets such as architecture, sculpture, and greening, the brightness ratio of the brightness to the environmental background is also considered.
See Table 3. The brightness distribution of each component follows the principle of master-slave relationship to achieve the overall harmony.
6 Light Pollution Table 3 North American Lighting Engineering Association Lighting Manual (8th Edition) recommended for commercial pedestrian street light pollution including extra light to the sky and outdoor lighting effects than the intrusive light in the home. In the ambient lighting outside the commercial pedestrian street, the maximum brightness of the light pollution lighting effect is mainly glare, and the prevention of glare will be one of the main means to control light pollution.
Glare is divided into disability glare and discomfort glare. The slightly emphasized emphasis of the commercial pedestrian street outer ring in harmony with the surrounding environment is very emphasis on the 1:21:31:5 ambient lighting is generally uncomfortable glare. The reasons for this are as follows: the brightness of the surface of the light source or the reflecting surface of the lamp is high; the surrounding environment is dark, and the brightness of the eye is very low, even if the surface brightness of the light source or the lamp is low, glare is caused; Within, the larger the light source area and the larger the number, the more significant the glare is; the closer the light source is to the line of sight, the smaller the angle with the line of sight, and the more significant the glare.
The method of controlling discomfort glare is to limit the brightness of the light source or luminaire in the viewing direction. According to Bommel's experimental conclusions.
The recommended values ​​for uncomfortable glare in residential areas can be obtained: LA()25 should be less than: 1250, when the installation height is less than 4.500, when the installation height is between 4 5m and 6m; 000, the installation height is greater than 6m. Although it is derived from the environment of residential areas, it also has certain reference significance for glare control of ambient lighting outside commercial pedestrian streets.
For the control of light pollution, reference can be made to the relevant regulations and standards of CIE and developed countries. See Table 4. Table 4 Recommended for controlling the maximum value of the luminosity parameter of the interference light (light pollution). The maximum luminosity parameter used, calculated or measured based on the ambient or mixed living area bright ambient dark environment vertical illuminance used in the facility On the side of the site, on the vertical plane parallel to the relevant side, the recommended maximum is the intensity of the direct component of the illuminance (I used to see the bright surface of the luminaire, which is likely to cause damage to neighboring households or users) Trouble, not counting the increments of the valve limits seen in a short time or in an instant, only based on the impact of the facility itself, does not include the impact of existing lighting in this area, the restrictions apply only to the relevant locations seen on the roads and The recommended direction is 10cd/m2, the brightness is 1cd/m2, and the brightness is 0.1cd/m2.
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