Abstract
Recently automatic wiper is equipped widely on vehicle. It can provide clear visibility to the driver but cause troublesome when the wiper do not work properly especially at drizzling rain because the rain sensor detect only adhesion rate of raindrop on the windshield. In this paper, we investigated the mechanism of driver’s control of windshield wiper by using driving simulator. We found that the major factors that influence on driver’s control of windshield wiper are increase in adhesion number, size and adhesion position of the raindrop. We also found that driver’s control of windshield wiper is caused by not only from decrease of visibility but also from attention attracted by raindrops (visual attention).