Camera-link and synchronism in automotive multi-vision systems

Abstract

Cameras are excellent ways of non-invasively monitoring the interior and exterior of vehicles. The motivations for cabin monitoring are largely safety related and include occupant detection, occupant classification, and driver vigilance/drowsiness monitoring. Exterior vehicular monitoring has wider motivations including road surface condition monitoring, lane-departure warning systems, blind spot warning, collision warning/mitigation/avoidance, vehicle security, traffic sign detection and adaptive cruise control. The large number of cameras envisaged, necessitates the development of a novel, high performance methodology for interfacing several cameras to a central processing hub over a single lightweight cable whilst preserving a high degree of synchronicity between stereovision or multivision sets. Such a solution, which is also backward compatible with the Camera-Link® standard, is thus presented. This results in substantial cabling, weight and cost savings while simultaneously guaranteeing superior performance. A stereovision design and implementation is presented that makes use of prototype, ultra-high dynamic range, automotive-grade image sensors developed by ATMEL Grenoble SA as part of the European FP6 Project - SENSATION (Advanced Sensor Development for Attention, Stress, Vigilance and Sleep/Wakefulness Monitoring).