Perceptual Attention to Contact Analogue Head-Up Displays
Leonard Stapleton HUSAT, Loughborough University, Leics., UK
Driving under adverse viewing conditions (e.g., at night, during dusk, in fog, etc.) is commonly recognized as a contributing factor in accident causation (e.g., Hills, 1980; Olson, 1988). Recent developments address providing drivers with additional visual information under such conditions (see, e.g., Mulvanny, 1993). Such technologies are generically referred to as vision enhancement systems (VESs). These systems acquire an image of the forward portion of the road scene ahead, which is then presented in an enhanced format to the driver. The system of interest in the present study uses a head-up display (HUD) format to provide the driver with the enhanced information.
With a HUD system, real-time video footage of the central portion of the road scene ahead is obtained, using, for example, an infrared camera. The obtained image is processed to convert it into a visible format. This image is then reflected off the inside of the front windshield or an intermediate virtually transparent screen. The optics that project the image simultaneously collimate it so that it appears on a focal plane at some distance in front of the driver (see Fig. 15.1).
The fields of view of the camera and the HUD image are matched so that the image overlays the portion of the forward road scene that is viewed by the camera. Thus, elements within the image overlay the objects and