| 摘要 |
PURPOSE:To plot a map so that it may be similar to a landscape which is actually seen by obtaining the advancing direction theta of an automobile, performing rotational transformation for an angle theta with center at the position of the automobile, then projection-converting the map and plotting it on the screen of a display. CONSTITUTION:Map data in accordance with the present position of the automo bile is read out from a CD-ROM 1 and stored in a map data buffer memory 8, then a specified bird's-eye view is plotted. When the automobile moves a specified distance and reaches a specified point P on a planar map, a system controller CPU 7 obtains the advancing bearing theta of the automobile from a bearing sensor 3 through a CPU 5 for calculating a position and performs coordi nate rotating transformation processing so that the map may be rotated by thetawith center at the position P. Next, the controller 7 performs the projection- converting processing by taking the advancing direction as the direction of the line of sight and a specified height Q backward from the position P as the point of sight. The controller transmits the obtained map data to a display device 10 so as to display the bird's-eye view on a CRT. |
