| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an inexpensive traffic flow measuring device of high accuracy. <P>SOLUTION: A fisheye camera comprising a fisheye lens and a variable focus lens for enlarging an image of the fisheye lens is mounted on the upper part of a post of a floodlight of a median strip, turning the center of the visual field directly below. The focus of the variable focus lens is adjusted according to a mounted situation such as the height of the post. To avoid a dead angle of the visual field of the fisheye camera caused by the post of the floodlight, traffic flow is measured by extracting the visual field from a point directly below the camera to the upstream end of the visual field in a lane with the fisheye camera mounted side set as the upstream side in a running direction, and extracting the visual field from the point directly below the camera to the downstream end of the visual field in a lane with the fisheye camera mounted side set as the downstream side in the running direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
