Guillaume Mario Dotreppe

Daytime Running Lamps (DRLs) are a crucial feature in vehicle design by enhancingvehicle visibility. According to ECE R48 regulations, current European standardsrequire two DRLs to be installed at a minimum distance of 600 mm apart.With advancements in technology and changing preferences in lighting aesthetics,there has been growing demand for the design of continuous single strip DRLs.This study analyses the influence of DRL configuration on left turn critical gapestimation and vehicle detection distance. Specifically, three configurations werecompared: no DRL, single DRL, and dual DRL. Psychophysical experiments wereconducted in a real-world environment, involving 59 participants who performed ve-hicle detection and left turn critical gap judgment tasks under two speed scenarios(50 km/h and 90 km/h). The data were analyzed using independent-samples andpaired-samples t-tests. The results showed that single and dual DRLs performed sim-ilarly in both tasks. Therefore, single DRLs, when matched in luminous intensity,provide road safety related performance comparable to dual DRLs and can thereforebe considered an optional alternative within the current regulatory context. Fur-thermore, irrespective of the DRL configuration, vehicle detection results showedthat participants detected vehicles at longer distances with DRL turned on. Olderparticipants chose longer left turn critical gaps than younger drivers. Additionally,higher oncoming vehicle speeds led to larger left turn critical gaps. At 50 km/h,males detected dual DRLs earlier than females.Overall, these findings confirm the visibility benefits of DRLs and highlight the com-bined effects of speed, age, gender, and DRL configuration.

Light electric vehicles within the L category are expected to play a significant role in promoting sustainable urban transport, advantageous for both society and the environment. The batteries in these vehicles are well suited for swapping, necessitating appropriate standards. This paper outlines the European Stan4SWAP project, which analyzed the standardization and regulation framework relevant to this application, and drafted the standardization roadmap which highlights development needs on short, medium and long term.

Light electric vehicles within the L category are expected to play a significant role in promoting sustainable urban transport, advantageous for both society and the environment. The batteries in these vehicles are well-suited for swapping, necessitating appropriate standards. This paper outlines the European Stan4SWAP project, which analyzed the standardization and regulation framework relevant to this application, and drafted the standardization roadmap which highlights development needs on short, medium and long term. This paper was originally presented on the EVS38 in Gothenburg [1] and has been expanded to include the outcomes of the project.

Daytime Running Lamps (DRLs) are a crucial feature in vehicle design by enhancing vehicle visibility. Accordingto ECE R48 regulations, current European standards require two DRLs to be installed at a minimum distance of600 mm apart. However, advancements in light source technology and material science currently allow for moreinnovative designs, such as a single continuous DRL spanning the front of a vehicle. This layout raises importantquestions about the safety implications of single DRL configurations compared with the traditional dual DRL setup.This study compares the performance of no DRL, single DRL and dual DRL configurations. Psychophysical testswith participants are performed in a real environment. Participants completed a vehicle detection and a left turncritical gap judgment task across two different speed scenarios (50 km/h and 90 km/h). The results show that singleand dual DRLs perform similarly in left turn critical gap and vehicle detection analyzes. Thus, single DRLs, whenmatched in luminous intensity, provide road safety related performance comparable to dual DRLs and can therefore beconsidered a optional alternative within the current regulatory context. When comparing the no DRL condition withthe DRL installed condition, the vehicle detection analysis results showed that participants detected vehicles at longerdistances under the (single or dual) DRL conditions, indicating that DRLs enhance vehicle visibility. Meanwhile, olderparticipants tended to choose longer left turn critical gaps than younger drivers, indicating more cautious behavior,while participants overall accepted larger left turn critical gaps at higher vehicle speeds in response to greater perceivedtraffic risk and uncertainty.

An important aspect of photometry is the use of baffles to block stray light, such as light reflected of the walls and floor, or light from other sources, from reaching the detector. The detector will often be placed in a baffle tube to limit the field-of-view of the detector to a narrow field around the optical axis, and the tube itself will usually have internal apertures to block reflections from the sides of the tube. The inside edges of the internal apertures can forward-diffract light onto the detector. In most cases this may be negligible, but for highest-accuracy applications may be significant. This paper describes a method to use stellation, i.e. introducing “teeth” to the inside edge of the internal apertures of a baffle tube, to reduce the forward diffraction by as much as 50 %.

Vehicular Visible Light Communication (V-VLC) offers a compelling alternative communication technology for Intelligent Transportation Systems, leveraging its license-free spectrum, wide bandwidth, energy efficiency, and existing transmitters. Accurate optical channel modelling is essential for evaluating V-VLC feasibility and performance in vehicular environments. For this, accurate transmitter representations are required. Low beam headlights and daytime running lights are primary candidates for VLC transmitters, yet simplified light source models often lack photometric realism compared to actual vehicle headlights. A comparison of a Lambertian and a measured low-beam emission patterns reveals that Lambertian models underestimate communication range while overestimating mobility. A narrow beam better reflects the low beam irradiance but requires careful design considerations for an optimal representation. This study examines the differences between the source models commonly used and suggests alternative modelling approaches depending on the communication range.

Standardisation bodies including the CIE and IESNA propose several test distances for far-field photometry based on the applicability of the inverse square law. Depending on the beam width, luminaire size and configuration, various guidelines regarding the minimal test distance are proposed. Recent literature suggests some norms are overoptimistic and larger far-field distances are required. Furthermore, the proposed test distances are only based on observations along the optical axis, whereas a strong angular variation of the limiting photometric distance was recently demonstrated. Therefore, this work presents a comparison between the regulations and the observations made in recent literature, assessing the application region of the standardised test distances as a function of the luminaire characteristics and the location of the measurement equipment.

Unlike radio-frequency (RF) systems, including Wi-Fi and cellular networks, which encounter interference, bandwidth limitations, network congestion, and security vulnerabilities, Vehicular Visible Light Communication (V-VLC) offers a compelling alternative as a communication medium. Its unlicensed spectrum, extensive bandwidth, energy efficiency, and existing transmitters render it a promising option for vehicular communication in the context of Intelligent Transportation Systems. By integrating V-VLC with traditional RF communication systems, a vast ecosystem of interconnected vehicles can be realised, thereby enhancing safety and efficiency for future fleets of (autonomous) vehicles. Despite successful integration of VLC in indoor environments, further investigation is required for outdoor applications. This study examines current channel modelling approaches for V-VLC within the framework of Intelligent Transportation Systems. Through a review of the literature within the period between 2013 and 2024 the advancements of V-VLC as a valuable addition to vehicular networks, with a specific emphasis on photometric aspects of the optical channel models, are assessed.