A methodology for LED placement in luminaires without lenses for optimal illumination of complex target areas

Street lighting still faces some challenges, e.g., reducing power consumption, lowering light pollution, and making adaptive luminaires more effective among many other concerns. It is evident that the arrival of light-emitting diodes (LEDs) in lighting systems has altered the state-of-the-art and design strategies in lighting. In a traditional approach, a single lamp, i.e., a single light point, is used. Then, by means of lenses, the specification of the radiation pattern is met. However, LED lamps allow for higher flexibility. It is possible to configure many small light sources, positioned and oriented at will. In this paper, a novel software tool able to provide the most suitable solution starting from a certain target lighting specification is proposed. This tool specifies the smallest number of LED required, their geometric orientation, and power levels in order to comply with all the specifications. It is especially useful when trying to light up an irregular, twisted area, although this methodology can be adapted to any geometry. Furthermore, to validate the proposed methodology, two lamps were tested in the streets of Oviedo, Spain, using a staggered arrangement.