How road surfaces reflect light in space is a physical characteristic that plays a key role in the design of road lighting installations: by European Standards the average luminance is the target quantity to assure the required safety conditions of the motorized road traffic. Lighting systems are designed (luminous flux installed per kilometre) to comply with the above requirement, starting from reference values of road surfaces reflection published in an old scientific document. These data are obsolete and not representative of current road surfaces, but they are still used to design current LED lighting systems. European Community funded a SURFACE project to provide to EU standard organization new traceable reference data, representative of current road surfaces used in EU. The paper presents the data collections and the impact on road lighting of using available old reference data versus SURFACE collected data of current road surfaces. Results highlight advantages in using bright pavements as well the need for introducing systems for flux control in road lighting installation to compensate for the discrepancies between current reference data and actual road surface data.
Taking into account the actual photometric characteristics of a road surface to design and then adjust a lighting installation is seldom done. In a lighting renovation, one of the Commission Internationale de l'Eclairage's standard r-tables is arbitrarily chosen although they are no longer representative of the characteristics of current road surfaces. The objective of the study is to assess an optimized, evolutive pavement and lighting combination, called Lumiroute®. To do this, two conventional designed sections were compared with two Lumiroute® sections. On-site measurements of road photometry, luminance and power consumption were conducted at regular intervals for three years. This paper presents the results of the photometric study together with an economic analysis. The Lumiroute® sections offer optimized performance and increased efficiency in comparison with the ordinary sections, particularly with regard to light and energy performance.
ABSTRACT:With recent developments in the field of technology and computer science, conventional methods are being supplanted by laser scanning and digital photogrammetry. These two different surveying techniques generate 3-D models of real world objects or structures. In this paper, we consider the application of terrestrial Laser scanning (TLS) and photogrammetry to the surveying of canal tunnels. The inspection of such structures requires time, safe access, specific processing and professional operators. Therefore, a French partnership proposes to develop a dedicated equipment based on image processing for visual inspection of canal tunnels. A 3D model of the vault and side walls of the tunnel is constructed from images recorded onboard a boat moving inside the tunnel. To assess the accuracy of this photogrammetric model (PM), a reference model is build using static TLS. We here address the problem comparing the resulting point clouds. Difficulties arise because of the highly differentiated acquisition processes, which result in very different point densities. We propose a new tool, designed to compare differences between pairs of point cloud or surfaces (triangulated meshes). Moreover, dealing with huge datasets requires the implementation of appropriate structures and algorithms. Several techniques are presented : point-to-point, cloud-to-cloud and cloud-to-mesh. In addition farthest point resampling, octree structure and Hausdorff distance are adopted and described. Experimental results are shown for a 475 m long canal tunnel located in France.
The objective of this work is to develop tools and methods for managers, lighting designers and road builders to optimize lighting both in interurban and urban areas. The goal is a complete characterization of the photometry of a large pavement sample panel, according to the criteria usually used in lighting such as Q0 and S1 and a characterization with an observation angle more adapted to the urban environment. In this contribution, the results of the initial characterisation of the pavement sample panel at 1° are presented.
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