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1、A high speed tri-vision system for automotive applicationsMarc Anthony Azzopardi & Ivan Grech & Jacques LeconteAbstractPurpose Cameras are excellent ways of non-invasively monitoring the interior and exterior of vehicles. In particular, high speed stereovision and multivision systems are important f
2、or transport applications such as driver eye tracking or collision avoidance. This paper addresses the synchronisation problem which arises when multivision camera systems are used to capture the high speed motion common in such applications. MethodsAn experimental, high-speed tri-vision camera syst
3、em intended for real-time driver eye-blink and saccade measurement was designed, developed, implemented and tested using prototype, ultra-high dynamic range, automotive- grade image sensors specifically developed by E2V (formerly Atmel) Grenoble SA as part of the European FP6 project SENSATION (adva
4、nced sensor development for attention stress, vigilance and sleep/wakefulness monitoring). Results The developed system can sustain frame rates of 59.8 Hz at the full stereovision resolution of 1280 480 but this can reach 750 Hz when a 10 k pixel Region of Interest (ROI) is used, with a maximum glob
5、al shutte speed of 1/48000 s and a shutter efficiency of 99.7%. The data can be reliably transmitted uncompressed over standard copper Camera-Link cables over 5 metres. The synchronisation error between the left and right stereo images is less than 100 ps and this has been verified both electrically
6、 and optically. Synchronisation is auto- matically established at boot-up and maintained during resolution changes. A third camera in the set can be configured independently. The dynamic range of the 10bit sensors exceeds 123 dB with a spectral sensitivity extending well into the infra-red range. Co
7、nclusion The system was subjected to a comprehensive testing protocol, which confirms that the salient require- ments for the driver monitoring application are adequately met and in some respects, exceeded. The synchronization technique presented may also benefit several other auto- motive stereovis
8、ion applications including near and far- field obstacle detection and collision avoidance, road condition monitoring and others.KeywordsSynchronisation . High-speed automotive multivision . Active safety . Driver monitoring . Sensors1 IntroductionOver the coming years, one of the areas of greatest r
9、esearch and development potential will be that of automotive sensor systems and telematics 1, 2. In particular, there is a steeply growing interest in the utilisation of multiple cameras within vehicles to augment vehicle Human-Machine Interfacing (HMI) for safety, comfort and security.For external
10、monitoring applications, cameras are emerging as viable alternatives to systems such Radio, Sound and Light/Laser Detection and Ranging (RADAR, SODAR, LADAR/LIDAR). The latter are typically rather costly and either have poor lateral resolution or require mechanical moving parts.For vehicle cabin app
11、lications, cameras outshine other techniques with their ability to collect large amounts of information in a highly unobtrusive way. Moreover, cameras can be used to satisfy several applications at once by re-processing the same vision data in multiple ways, thereby reducing the total number of sens
12、ors required to achieve equivalent functionality. However, automotive vision still faces several open challenges in terms of optoelectronic-performance, size, reliability, power con- sumption, sensitivity, multi-camera synchronisation, inter- facing and cost.In this paper, several of these problems
13、are addressed. As an example, driver head localisation, point of gaze detection and eye blink rate measurement is considered for which the design of a dash-board-mountable automotive stereovision camera system is presented. This was developed as part of a large FP6 Integrated Project - SENSATION (Ad
14、vanced Sensor Development for Attention, Stress, Vigilance and Sleep/Wakefulness Monitoring). The overarching goal of extendable to multivision systems 58.The camera system is built around a matched set of prototype, ultra-high dynamic range, automotive-grade, image sensors specifically developed an
15、d fabricated by E2V Grenoble SA for this application. The sensor which is a novelty in its own right, is the AT76C410ABA CMOS monochrome automotive image sensor. This sensor imple- ments a global shutter to allow distortion-free capture of fast motion. It also incorporates an on- chipMulti-ROI featu
16、re with up to eight Regions Of Interest (ROI) with pre- programming facility and allows fast switching from one image to another. In this way, several real-time parallel imaging processing tasks can be carried out with one sensor. Each ROI is independently programmableon-the-flywith respect to integration time, gain, sub-sampling/binning, position, width and height.A fairly comprehensive series of“bench tests”were conducted in order to test the validity
