Optimal design of optical system for LED road lighting with high illuminance and luminance uniformity

Hu, Xiaojia; Qian, Keyuan

doi:10.1364/ao.52.005888

Cited by 37 publications

(18 citation statements)

References 7 publications

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“…Luo et al focused on achieving a uniform distribution of luminance onto the road surface, where irradiance distribution was not considered, and little discussion was provided for the final illumination pattern and the stray light control in sidewalk direction [11]. Some other researchers used tilted whole lens system and the light source to realize the shifted illumination pattern onto the road surface [12][13][14][15][16][17][18]. The discontinuous optical surfaces are often used in these designs to control the ray direction, potentially leading to glare.…”

Section: Introductionmentioning

confidence: 99%

Catadioptric freeform optical system design for LED off-axis road illumination applications

Zhu¹,

Ma²,

Hu³

et al. 2017

Opt. Express

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Abstract:The aim of this paper is to develop a new composite structure of catadioptric optical system containing both freeform refractive surface and freeform total internal reflective (TIR) surface for LED road illumination applications. The role of freeform refractive part is to generate the shifted general rectangular illumination pattern to optimally match the shape of the road surface. The application of TIR mechanism is aimed to control the stray light in the sidewalk direction of the road luminaire and maximize the efficient energy efficiency. In this paper, we use the "double pole" ray mapping technique to design the refractive optical surface and the θ-φ coordinate ray mapping technique to derive the freeform TIR surface. The simulation shows that the novel catadioptric design has relatively high collection efficiency, thus high average illuminance level inside the effective illumination area. This lens also has good control of stray light on the backside of the road luminaire.

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Section: Introductionmentioning

confidence: 99%

Catadioptric freeform optical system design for LED off-axis road illumination applications

Zhu¹,

Ma²,

Hu³

et al. 2017

Opt. Express

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“…Thus the propagation angle δ of the ray incident upon the outer surface must decrease monotonically from a positive maximum value to a negative minimum value with increasing emission angle ϕ. From this tendency, the propagation angle δ is approximated to decrease linearly with an increase in emission angle ϕ, as follows: (12) where δo and βo denote the propagation angles when a ray whose emission angle is ϕsplit enters and emerges from the outer surface of the peripheral TIR part, and are associated with the intersection point COT. In addition, k is a constant that determines the propagation angle when a ray whose emission angle is maximum (ϕ = ϕmax) enters the outer surface of the peripheral TIR part.…”

Section: (3)mentioning

confidence: 99%

“…The LED lens can be designed using a differential equation method [8][9][10][11], a parameter optimization method [12][13][14][15], or a simultaneous multiple surface (SMS) method [16][17][18], and it often includes one or more freeform surfaces, for the sake of low price and high efficiency. The differential equation method is an LED lens design method in which differential equations relating to the propagation of rays through an LED lens are solved assuming that one surface of the lens is already known; then the other surface is freeform.…”

Section: Introductionmentioning

confidence: 99%

“…20.5.614 flux efficiency of an LED lens with a single freeform free-form surface is limited by the other surface that is not set as the freeform surface. Parameter optimization is another design method, in which all surfaces of an LED lens are described parametrically, and the parameter values are adjusted using an optimization method so that a desired illuminance distribution can be formed, and simultaneously the maximum luminous flux efficiency can be attained [12][13][14][15]. However, the parameter optimization method has a drawback, in that the lens performance depends on the initial values of the parameters and may become trapped in a local minimum during optimization.…”

Section: Introductionmentioning

confidence: 99%

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Design Method for a Total Internal Reflection LED Lens with Double Freeform Surfaces for Narrow and Uniform Illumination

Yang¹,

Park²,

Beom‐Hoan³

et al. 2016

Journal of the Optical Society of Korea

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In this paper, we propose a novel differential equation method for designing a total internal reflection (TIR) LED lens with double freeform surfaces. A complete set of simultaneous differential equations for the method is derived from the condition for minimizing the Fresnel loss, illumination models, Snell's Law of ray propagation, and a new constraint on the incident angle of a ray on the light-exiting surface of the lens. The last constraint is essential to complete the set of simultaneous differential equations. By adopting the TIR structure and applying the condition for minimizing the Fresnel loss, it is expected that the proposed TIR LED lens can have a high luminous flux efficiency, even though its beam-spread angle is narrow. To validate the proposed method, three TIR LED lenses with beam-spread angles of less than 22.6° have been designed, and their performances evaluated by ray tracing. Their luminous flux efficiencies could be obviously increased by at least 35% and 5%, compared to conventional LED lenses with a single freeform surface and with double freeform surfaces, respectively.

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“…Noor-EAlam et al, [14], proposed a grid-based lighting location problem where mixed integer programming (MIP) models were developed to minimise the amount of darkness and excess supply of light in an open park. Optimising the design of specific parts relating to the luminaire itself has been attempted in order to minimise energy consumption and optimise light distribution [15]. Other topics related to the optimisation of light photometric factors include the problem of optimising road lighting distribution [16], and the optimisation of the height of luminaires to improve energy efficiency and satisfy target illuminance of demand areas [17].…”

Section: Introductionmentioning

confidence: 99%

A Multi-Objective Mixed Integer Programming Model for Minimising Obtrusive Effects and Installation Costs of Night-time Lighting on Construction Sites

Hammad¹,

Akbarnezhad²,

Rey³

2016

Proceedings of the International Symposium on Automation and Robotics in Construction (IAARC)

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The increase in the rate of urbanisation worldwide has led to a boom in the construction industry sector in most major cities. To cope with the associated rising demand for further services and facilities, contractors find themselves frequently obliged to extend working hours on construction sites. Construction of major infrastructure projects, such as road works, is conducted at times of the day when less disruption is likely to result to the affected population. As a result, night work is now a common sighting on many construction sites. To allow for better vision for construction personnel on sites, floodlights are deployed during night work to light up work zones. There is an expense however to the adoption of construction lighting, particularly when considering the social and environmental impacts arising due to light pollution. In a residential district, and especially when infrastructure projects are taking place, the lighting system utilised on a construction site can be a cause of major disruption to the people and wildlife in the vicinity of the site. This paper attempts to model the problem of construction lighting through an optimisation model that minimises both construction light set-up costs and the maximum light pollution perceived at lightsensitive receivers. At the same time, the model ensures an appropriate coverage level to avoid impairing workers' vision on site. The developed formulations take the format of a Mixed Integer Programming model. An illustrative case study is applied to a construction project to demonstrate the applicability of the model.

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Optimal design of optical system for LED road lighting with high illuminance and luminance uniformity

Cited by 37 publications

References 7 publications

Catadioptric freeform optical system design for LED off-axis road illumination applications

Catadioptric freeform optical system design for LED off-axis road illumination applications

Design Method for a Total Internal Reflection LED Lens with Double Freeform Surfaces for Narrow and Uniform Illumination

A Multi-Objective Mixed Integer Programming Model for Minimising Obtrusive Effects and Installation Costs of Night-time Lighting on Construction Sites

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