The Best of Two Worlds — Innovations in Light Measurement Technology

The Best of Two Worlds — Innovations in Light Measurement Technology

From legislation and standardization to the practical assessment of light

Chr. Schwanengel¹, Dr. Udo Krüger², Bob Liu^3*

^1,2TechnoTeam BV GmbH; Ilmenau, Germany

3Light-All; Shanghai, P.R.China

*Contact email address: info@technoteam.de; bob-liu@light-all.com

Abstract — The contribution is focused on the trends in the standardization of laboratory conditions and the evaluation of light. We will present how the predominantly theoretical work in CIE and GTB working groups is being transformed into productive laboratories that enable the automotive industry to monitor and develop its own innovations in terms of measurement technology.

In the CIE TC2-67 - "Photometry of road illumination devices, light signalling devices and retroreflective devices for road vehicles" (currently undergoing committee draft status) camera-based measurement laboratories, which are crucial for headlamp development, are being included for the first time. The best of two worlds is the combination of classical goniophotometry in combination with a high-contrast camera.

The basis for selecting suitable high-contrast cameras is described in the Technical Report CIE244:2021 - "Characterization of imaging luminance measuring devices (ILMDs)" published last year. This report describes for the first time extended quality indices that can be used to classify ILMDs suitable for this application.

Suitable photometric and geometric ILMDs (referred to as type II) allow laboratories with an additional measuring screen to work considerably faster and, in the case of VELAS (VEhicle Lighting Assessment System), even to measure complete vehicles. VELAS is used for assessment in accordance with C-NCAP in China and is the world's first goniometer measurement laboratory for complete vehicles. Combining a high-contrast camera with a goniophotometer lays the foundation for the GTB Taskforce, which deals with evaluating ADB (Adaptive Driving Beam) systems on vehicles under laboratory conditions (TF-VLLTP).  

Keywords-component; CIE; GTB; standardisation; assessment of light