| 摘要 |
PURPOSE:To estimate a correct current position of a moving object by updating position information received respectively by first and second receiver means for receiving position information from a transmitter provided on a signpost and position information from global positioning system (GPS) satellites. CONSTITUTION:A processor 5 samples output signals of a bearing sensor 1 and a distance sensor 2 with predetermined intervals, resolves them into a two-dimensional coordinate (x, y) in east, west, south and north directions and adds them to a previous accumulated coordinate (X, Y) to calculate a current coordinate (X1, Y1). When the processor 5 receives position information from a position information transmitter 8 with a vehicle V passing by a signpost 7, it replaces the calculated coordinate (X1, Y1) with the position information. The processor 5, when it receives position signals from GPS satellites 9a to 9c, replaces the calculated coordinate (X1, Y1) with the position information. Since position information from the transmitter 8 at the post 7 is absolute position information, a correct current position of a moving object can be estimated. |
