Automotive Mirror-Replacement with Displays – Requirements and Test Procedures according to ISO 16505 and UN ECE R.46

This contribution presents a discussion of automotive mirror replacement by camera monitor systems (CMS) with a focus on the in vehicle displays and measurement of image quality. Display based automotive mirror replacement is a growing research and development field. Such systems can be used to improve factors of the indirect vision of the driver, to improve the aerodynamics and to optimize the fuel economy of new vehicles. The normative framework of the standard ISO 16505:2015 in combination with the amendment on UN ECE Regulation No. 46 enables the replacement of mandatory rear-view mirrors by CMS for road vehicles including passenger cars and commercial vehicles. Based on the characteristics of conventional mirrors, a CMS has to be designed for comparable functionality. This includes the real time behavior, the system resolution, and the dimensions of the displayed object and field of view. In order to evaluate and compare such systems, specific emphasis has to be given to the appropriate image quality criteria and testing of the criteria. In this contribution, beginning with system requirements, incorporating additional standards and regulations, different CMS requirements and test procedures according to ISO 16505 and UN ECE R.46 are discussed. Beside the image quality criteria of ISO 16505 the Regulation 46 requires also an operation mode in which the driver of the vehicle equipped with CMS e.g. can recognize two point light sources (e.g. passing beam headlights) rendered as two distinguishable separate point light sources. For testing this requirement two different parameter are applicable, the so-called point light source detection factor (PLSDF) or the so-called point light source contrast factor (PLSCF). A lab based measurement set up for this purpose is introduced. The contribution includes the following parameter and test procedure: - Point light sources test method - Magnification and resolution - Image quality e.g. luminance and contrast rendering - Time behavior of the system - Ergonomic aspects