Lighting Spacing in Curved Tunnel Using LED Lights

At present, there are no specified rules that clarify the relationship between the arrangement of LED lights, spacing of LED lights, curvaturer adius, and blind area. Thus, the maximum allowable spacing and maximum blind area are explored in terms of different luminaire arrangements with the two constraints of flicker frequency and blind area boundary. First of all, according to four luminaire arrangements, i.e., outside unilateral arrangement, inside unilateral arrangement, symmetrically bilateral arrangement, and alternate bilateral arrangement, the expression with respect to the blind area, luminaire spacing and tunnel curvature radiusis obtained with the aid of plane geometry, and through partial differential, their relationships are determined. Secondly, the relationship between the maximum allowable spacing and the parameters of the blind area boundary (car length and car width) is analyzed with the blind area boundary as the main constraint. Finally, by partial differential or algebraic method, different car types are used as examples for verifying the maximum allowable blind area and maximum allowable luminaire spacing with different luminaire arrangements. It is found when either the luminaire spacing or the curvature radius is settled, the blind area increases with the luminaire spacingor curvature radius.In the case of inside unilateral arrangement, the luminaire spacing increases with the car length or curvature radius. For outside unilateral arrangement, it increases with the car length or curvature radius, while decreasing with the car width. If the blind area is considered for bilateral arrangement, the luminaire spacing does not meet the requirements, indicating that only if luminaire spacing is large enough, the blind area exists. Through the comparison of different car models, it is concluded that inside unilateral arrangement is desirable for unilater alluminaire arrangement, and both symmetrically bilateral arrangement and alternate bilateral arrangement are acceptable for bilateral luminaire arrangement.